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Sample records for bruneri reduviidae triatominae

  1. Spermatogenesis in Nesotriatoma bruneri (Usinger 1944) (Hemiptera, Triatominae).

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    Reis, Y V; Alevi, K C C; Moreira, F F F; Azeredo-Oliveira, M T V

    2016-08-19

    The Nesotriatoma genus consists of the species N. flavida N. bruneri and N. obscura, forming the Flavida complex. Variation in the size and morphological differences intraspecific of N. flavida led to the description of N. bruneri. Two years later, the same author proposed the synonymization of N. bruneri with N. flavida. Only in 1981 the specific status N. bruneri was recovered by means of morphological analysis of the genitalia. However, recently by genetic analysis, it was suggested that N. bruneri and N. flavida should be again synonymized. As Chagas disease has no cure, the main way to minimize the incidence of this disease is by vector control. Thus, grouping biological data from these hematophagous insects can assist in the development of vector control programs and mainly assist in taxonomic issues of synonymization. Thus, this paper describes spermatogenesis of N. bruneri. Three adult N. bruneri males were cytogenetically analyzed. The meiotic behavior observed for N. bruneri was very similar to that observed for the triatomine species with 23 chromosomes: during prophase, chromatin compaction was observed, the chromocenter composition was characterized (X 1 , X 2 and Y), and the species karyotype was confirmed as 2n = 23 (20A + X 1 X 2 Y), as it was observed for N. flavida. Moreover, it was possible to observe anaphase and telophase. Thus, this study describes reproductive aspects of N. bruneri in order to contribute to the biological knowledge of these insects of epidemiological importance. Furthermore, this corroborates the synonymization of N. bruneri with N. flavida.

  2. Why are the subfamily relationships of Triatominae (Hemiptera: Reduviidae) important?

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    Schaefer, Carl W.

    2005-01-01

    Why are the subfamily relationships of Triatominae (Hemiptera: Reduviidae) important?-This question is really two: Is Triatominae a phylogenetically valid monophyletic subfamily; and, if it is, to what other reduviid subfamilies is it most closely related? If the answer to the first question is Yes, then what one knows about one member of Triatominae may be true for other members; if the answer is No, then no such prediction can be made. Because many members of Triatominae are of medical impo...

  3. An overview on the ecology of Triatominae (Hemiptera:Reduviidae).

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    Galvão, Cleber; Justi, Silvia A

    2015-11-01

    Chagas disease, the American trypanosomiasis, is an important neglected tropical illness caused by the flagellate protozoan Trypanosoma cruzi (Kinetoplastida, Trypanosomatidae) and transmitted by insects of the subfamily Triatominae (Hemiptera: Reduviidae). Here we provide an overview on the current knowledge about Triatominae ecology, its association with human, T. cruzi infection and the immediate consequences of habitat fragmentation. We also discuss the geographic distribution of the species and the importance of predicting their distributions to control programs. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Cytogenetics and genome evolution in the subfamily Triatominae (Hemiptera, Reduviidae).

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    Panzera, F; Pérez, R; Panzera, Y; Ferrandis, I; Ferreiro, M J; Calleros, L

    2010-01-01

    The subfamily Triatominae (Hemiptera, Reduviidae), vectors of Chagas disease, includes over 140 species. Karyotypic information is currently available for 80 of these species. This paper summarizes the chromosomal variability of the subfamily and how it may reveal aspects of genome evolution in this group. The Triatominae present a highly conserved chromosome number. All species, except 3, present 20 autosomes. The differences in chromosome number are mainly caused by variation in the number of sex chromosomes, due to the existence of 3 sex systems in males (XY, X(1)X(2)Y and X(1)X(2)X(3)Y). However, inter- and intraspecific differences in the position, quantity and meiotic behavior of constitutive heterochromatin, in the total genome size, and in the location of ribosomal 45S rRNA clusters, have revealed considerable cytogenetic variability within the subfamily. This cytogenetic diversity offers the opportunity to perform cytotaxonomic and phylogenetic studies, as well as structural, evolutionary, and functional analyses of the genome. The imminent availability of the complete genome of Rhodnius prolixus also opens new perspectives for understanding the evolution and genome expression of triatomines. The application of fluorescence in situ hybridization for the mapping of genes and sequences, as well as comparative analyses of genome homology by comparative genomic hybridization will be useful tools for understanding the genomic changes in relation to evolutionary processes such as speciation and adaptation to different environments. Copyright 2010 S. Karger AG, Basel.

  5. Molecular phylogeny of Triatomini (Hemiptera: Reduviidae: Triatominae).

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    Justi, Silvia Andrade; Russo, Claudia A M; Mallet, Jacenir Reis dos Santos; Obara, Marcos Takashi; Galvão, Cleber

    2014-03-31

    The Triatomini and Rhodniini (Hemiptera: Reduviidae) tribes include the most diverse Chagas disease vectors; however, the phylogenetic relationships within the tribes remain obscure. This study provides the most comprehensive phylogeny of Triatomini reported to date. The relationships between all of the Triatomini genera and representatives of the three Rhodniini species groups were examined in a novel molecular phylogenetic analysis based on the following six molecular markers: the mitochondrial 16S; Cytochrome Oxidase I and II (COI and COII) and Cytochrome B (Cyt B); and the nuclear 18S and 28S. Our results show that the Rhodnius prolixus and R. pictipes groups are more closely related to each other than to the R. pallescens group. For Triatomini, we demonstrate that the large complexes within the paraphyletic Triatoma genus are closely associated with their geographical distribution. Additionally, we observe that the divergence within the spinolai and flavida complex clades are higher than in the other Triatoma complexes. We propose that the spinolai and flavida complexes should be ranked under the genera Mepraia and Nesotriatoma. Finally, we conclude that a thorough morphological investigation of the paraphyletic genera Triatoma and Panstrongylus is required to accurately assign queries to natural genera.

  6. Complete mitochondrial genome of Triatoma infestans (Hemiptera, Reduviidae, Triatominae), main vector of Chagas disease.

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    Pita, Sebastián; Panzera, Francisco; Vela, Jesús; Mora, Pablo; Palomeque, Teresa; Lorite, Pedro

    2017-10-01

    The complete mitogenome of Triatoma infestans, the main vector of Chagas disease in South America, was obtained by combining Illumina and Sanger sequencing sequence data. The 17,301bp long genome contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region. The number, order and orientation of mitochondrial genes are the same as in T. dimidiata, the only Triatominae mt genome published so far. The main differences between both mitogenomes are found in the control region and in the intergenic spacer between the nd1 gene and the tRNA-Ser. Comparative analysis with other Reduviidae species shows high conservation in the mt genome organization. Molecular phylogeny using all available complete mt genomes from Reduviidae species confirms the close relationship between Triatominae and Stenopodainae. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Geological Changes of the Americas and their Influence on the Diversification of the Neotropical Kissing Bugs (Hemiptera: Reduviidae: Triatominae)

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    Justi, Silvia A.; Galvão, Cleber; Schrago, Carlos G.

    2016-01-01

    Background The family Reduviidae (Hemiptera: Heteroptera), or assassin bugs, is among the most diverse families of the true bugs, with more than 6,000 species. The subfamily Triatominae (kissing bugs) is noteworthy not simply because it is the only subfamily of the Reduviidae whose members feed on vertebrate blood but particularly because all 147 known members of the subfamily are potential Chagas disease vectors. Due to the epidemiological relevance of these species and the lack of an efficient treatment and vaccine for Chagas disease, it is more common to find evolutionary studies focusing on the most relevant vectors than it is to find studies aiming to understand the evolution of the group as a whole. We present the first comprehensive phylogenetic study aiming to understand the events that led to the diversification of the Triatominae. Methodology/Principal Findings We gathered the most diverse samples of Reduviidae and Triatominae (a total of 229 Reduviidae samples, including 70 Triatominae species) and reconstructed a robust dated phylogeny with several fossil (Reduviidae and Triatominae) calibrations. Based on this information, the possible role of geological events in several of the major cladogenetic events within Triatominae was tested for the first time. We were able to not only correlate the geological changes in the Neotropics with Triatominae evolution but also add to an old discussion: Triatominae monophyly vs. paraphyly. Conclusions/Significance We found that most of the diversification events observed within the Rhodniini and Triatomini tribes are closely linked to the climatic and geological changes caused by the Andean uplift in South America and that variations in sea levels in North America also played a role in the diversification of the species of Triatoma in that region. PMID:27058599

  8. Geological Changes of the Americas and their Influence on the Diversification of the Neotropical Kissing Bugs (Hemiptera: Reduviidae: Triatominae).

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    Justi, Silvia A; Galvão, Cleber; Schrago, Carlos G

    2016-04-01

    The family Reduviidae (Hemiptera: Heteroptera), or assassin bugs, is among the most diverse families of the true bugs, with more than 6,000 species. The subfamily Triatominae (kissing bugs) is noteworthy not simply because it is the only subfamily of the Reduviidae whose members feed on vertebrate blood but particularly because all 147 known members of the subfamily are potential Chagas disease vectors. Due to the epidemiological relevance of these species and the lack of an efficient treatment and vaccine for Chagas disease, it is more common to find evolutionary studies focusing on the most relevant vectors than it is to find studies aiming to understand the evolution of the group as a whole. We present the first comprehensive phylogenetic study aiming to understand the events that led to the diversification of the Triatominae. We gathered the most diverse samples of Reduviidae and Triatominae (a total of 229 Reduviidae samples, including 70 Triatominae species) and reconstructed a robust dated phylogeny with several fossil (Reduviidae and Triatominae) calibrations. Based on this information, the possible role of geological events in several of the major cladogenetic events within Triatominae was tested for the first time. We were able to not only correlate the geological changes in the Neotropics with Triatominae evolution but also add to an old discussion: Triatominae monophyly vs. paraphyly. We found that most of the diversification events observed within the Rhodniini and Triatomini tribes are closely linked to the climatic and geological changes caused by the Andean uplift in South America and that variations in sea levels in North America also played a role in the diversification of the species of Triatoma in that region.

  9. Geological Changes of the Americas and their Influence on the Diversification of the Neotropical Kissing Bugs (Hemiptera: Reduviidae: Triatominae)

    OpenAIRE

    Justi, Silvia A.; Galv?o, Cleber; Schrago, Carlos G.

    2016-01-01

    Background The family Reduviidae (Hemiptera: Heteroptera), or assassin bugs, is among the most diverse families of the true bugs, with more than 6,000 species. The subfamily Triatominae (kissing bugs) is noteworthy not simply because it is the only subfamily of the Reduviidae whose members feed on vertebrate blood but particularly because all 147 known members of the subfamily are potential Chagas disease vectors. Due to the epidemiological relevance of these species and the lack of an effici...

  10. Comparative bionomics of four populations of Meccus longipennis (Hemiptera: Reduviidae: Triatominae) under laboratory conditions.

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    Martínez-Ibarra, José Alejandro; Nogueda-Torres, Benjamín; Licón-Trillo, Ángel; Villagrán-Herrera, María Elena; de Diego-Cabrera, José Antonio; Montañez-Valdez, Oziel Dante; Rocha-Chávez, Gonzalo

    2013-04-01

    The values of biological parameters related to the life cycles of four populations of Meccus longipennis (Reduviidae: Triatominae) were evaluated. Cohorts of each of the four studied populations from different geographical areas of Mexico were maintained under similar laboratory conditions and then compared. The population from El Saucito de Araujo was different from the other three studied populations, which could help explain the secondary importance of M. longipennis in the state of Chihuahua. This paper also supports the proposition that biological traits are important criteria for determining relationships between populations.

  11. Association between antennal phenotype, wing polymorphism and sex in the genus Mepraia (Reduviidae: Triatominae).

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    Moreno, Mariana Laura; Gorla, David; Catalá, Silvia

    2006-05-01

    Mepraia spinolai and Mepraia gajardoi (Hemiptera, Reduviidae) are only found in the arid regions of northern Chile. Mepraia is the only genus of Triatominae with marked wing polymorphism. Females of both species are micropterous, males of M. spinolai may be micropterous, brachypterous or macropterous, while males of M. gajardoi are always brachypterous. Because of this wing polymorphism, Mepraia can be used as a model to analyze morphological adaptations related to the flying activity and evolutionary relationships in the Triatominae. The study presented here analyses the antennal phenotype of the Mepraia species and carries out a comparison with the two species of Triatoma included in the spinolai complex (Triatoma eratyrusiformis and Triatoma breyeri). The analysis of the antennal phenotype of Mepraia showed a marked intraspecific phenotypic variability related with sex and wing condition. The number and length of multiporous trichoid sensilla (TH) on the pedicel are significantly higher and longer in winged males and are strongly reduced in females. The great length of the TH sensillum is an infrequent characteristic within Triatominae. The results show that phenetic distances between sexes are greater than between the two species. Similarity between the Mepraia species and T. eratyrusiformis was found as they all show long bristles (BR) and TH and two sized basiconic receptors (BA), a pattern that have not been observed in other species of Triatominae. These characters are not present in T. breyeri.

  12. Comparative biology of the two sister species of Triatominae (Hemiptera: Reduviidae Biologia comparativa de duas espécies irmãs de Triatominae (Hemiptera: Reduviidae

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    Ana Laura Carbajal de la Fuente

    2010-02-01

    Full Text Available INTRODUCTION: Triatoma pseudomaculata and T. wygodzinskyi (Hemiptera: Reduviidae: Triatominae are two Brazilian vectors of Chagas disease. The first is an arboricolous species in sylvatic environment and considered a vector of T. cruzi in peridomestic structures; the second, a rupicolous species in the wild environment of no epidemiological importance. In order to test the assumption that sister species share biological traits, comparative studies of their development cycle and blood ingestion were conducted. METHODS: Eggs laid by five field females of each species were randomly selected. The nymphs were observed daily and fed on mice weekly. The time required to pass through the different stages to adulthood was recorded in days. The triatomines were weighed individually before and after feeding. The mortality rate according to each nymphal stage was calculated. RESULTS AND CONCLUSIONS: Analysis of the results shows that they display only minor biological differences even though they exhibit a distinct ecology. This suggests that the biological traits are important criteria to determine the relationship between species.INTRODUÇÃO: Triatoma pseudomaculata e T. wygodzinskyi (Hemiptera: Reduviidae: Triatominae são dois vetores Brasileiros da doença de Chagas. A primeira é uma espécie arborícola em ambiente silvestre e considerada vetor do T. cruzi em estruturas peridomesticas. A segunda é rupícola em ambientes silvestres e sem importância epidemiológica. Com o objetivo de testar a hipótese que espécies irmãs compartilham características semelhantes, realizamos um estudo comparativo do ciclo biológico e ingesta alimentar. MÉTODOS: Ovos pertencentes a cinco fêmeas de cada espécie provenientes do campo foram selecionados aleatoriamente. As ninfas foram observadas diariamente e alimentadas com camundongos semanalmente. O tempo requerido para passar até o estágio adulto foi registrado em dias. Os triatomíneos foram pesados

  13. [Diversity of Triatominae (Hemiptera: Reduviidae) in Santander, Colombia: Epidemiological implications].

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    Esteban, Lyda; Montes, José Mauricio; Angulo, Víctor Manuel

    2017-01-24

    Domestic and wild triatomines in the department of Santander have an epidemiological impact, as recently they have been linked to outbreaks of acute Chagas disease. The analysis of their diversity and temporal variation contributes to the understanding of their biology and ecology in one of the most endemic areas of the country. To analyze triatominae diversity in two regions of Santander. We analyzed the triatomine records for Santander contained in the CINTROP-UIS entomology lab database. We grouped the information for two regions: the Middle Magdalena area and the Andean region, and for each one we designed species accumulation and range-abundance curves, we calculated diversity and equality indices, and we analyzed colonization and temporal variation or persistence of the community. Ninety five percent of triatomines came from the Andean area and 4.57% from Magdalena Medio, with nine and ten species each. The dominant species in the Andean area were Rhodnius prolixus and Triatoma dimidiata while in Magdalena Medio they were Rhodnius pallescens and Panstrongylus geniculatus. We found a greater diversity and richness in Middle Magdalena compared to the Andean area. The temporal variation showed persistence of communities over time. Results revealed differences in the diversity of the two regions and the potential of wild species to occupy artificial ecotopes. Triatomines intrusion and the recent involvement of wild species in the transmission of Trypanosoma cruzi emphasize the need to further investigate the ecology of these vectors in order to guide population control strategies.

  14. Description of the cave organ in three species of the genus Belminus (Hemiptera: Reduviidae: Triatominae) by optical and scanning electron microscopy.

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    Sandoval, Claudia Magaly; Nieves, Elsa; Angulo, Víctor Manuel; Aldana, Elis

    2011-09-01

    The cave organ is a sensory receptor in the antenna pedicel of some Reduviidae. This paper describes this organ for the first time in three species of the genus Belminus, Belminus corredori, Belminus ferroae and Belminus herreri, by optical and scanning electron microscopy. The structures presented a general pattern similar to one reported for other species of Triatominae.

  15. Biology of three species of North American Triatominae (Hemiptera: Reduviidae: Triatominae) fed on rabbits.

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    Martínez-Ibarra, José Alejandro; Alejandre-Aguilar, Ricardo; Paredes-González, Edgar; Martínez-Silva, Miguel Alejandro; Solorio-Cibrián, Miriam; Nogueda-Torres, Benjamín; Trujillo-Contreras, Francisco; Novelo-López, Mónica

    2007-12-01

    Aspects related to hatching, lifetime, number of blood meals for molting, mortality, feeding time, and postfeeding defecation delay were evaluated and compared in each instar of three North American Triatominae: Triatoma gerstaeckeri, Triatoma lecticularia and Triatoma protracta, all of them fed on rabbits. No significant differences (p > 0.05) were found among the three species regarding mean hatching rate, which was close to 20 days. Egg-to-adult development times were significantly shorter (p < 0.05) for T. lecticularia. Number of blood meals for molting to next instar ranged from one to five for T. protracta, and from one to six for T. gerstaeckeri and T. lecticularia. Mortality rates were higher in younger nymphs of T. lecticularia and T. protracta, while rates in T. gerstaeckeri were higher in fifth-instar nymphs. Mean feeding time was longest in T. gerstaeckeri, followed by T. lecticularia. More than twice the number of T. gerstaeckeri nymphs completed the development process, if compared to the nymphs from the other two species. Defecation delay was less than 10 min for T. lecticularia, T. protracta and the youngest nymphs of T. gerstaeckeri. Results point out that these three species may be important potential vectors of Trypanosoma cruzi for human populations, in areas of Mexico where these species are currently present.

  16. Biology of three species of North American Triatominae (Hemiptera: Reduviidae: Triatominae fed on rabbits

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    José Alejandro Martínez-Ibarra

    2007-12-01

    Full Text Available Aspects related to hatching, lifetime, number of blood meals for molting, mortality, feeding time, and postfeeding defecation delay were evaluated and compared in each instar of three North American Triatominae: Triatoma gerstaeckeri, Triatoma lecticularia and Triatoma protracta, all of them fed on rabbits. No significant differences (p > 0.05 were found among the three species regarding mean hatching rate, which was close to 20 days. Egg-to-adult development times were significantly shorter (p < 0.05 for T. lecticularia. Number of blood meals for molting to next instar ranged from one to five for T. protracta, and from one to six for T. gerstaeckeri and T. lecticularia. Mortality rates were higher in younger nymphs of T. lecticularia and T. protracta, while rates in T. gerstaeckeri were higher in fifth-instar nymphs. Mean feeding time was longest in T. gerstaeckeri, followed by T. lecticularia. More than twice the number of T. gerstaeckeri nymphs completed the development process, if compared to the nymphs from the other two species. Defecation delay was less than 10 min for T. lecticularia, T. protracta and the youngest nymphs of T. gerstaeckeri. Results point out that these three species may be important potential vectors of Trypanosoma cruzi for human populations, in areas of Mexico where these species are currently present.

  17. Bioactivity of the latex from Parahancornia amapa (Apocynaceae on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae under laboratory conditions

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    Marcio B. P. Lopes

    2014-12-01

    Full Text Available Bioactivity of the latex from Parahancornia amapa (Apocynaceae on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae under laboratory conditions. The aim of this study was to verify the effects of the methanolic fraction of the latex from Parahancornia amapa (Apocynaceae (PALAM on individuals of the species Rhodnius nasutus Stål (Hemiptera, Triatominae. Many of the insects treated with the substance presented deformities and these may interfere in the feeding and possibly hinder the reproductive capacity. They also presented significant mortality during the molt when compared to the control group, noting a gradual increase in mortality. The treated insects also presented delayed nymphal development (5th instar and higher adult longevity.

  18. Infestation by Triatoma pallidipennis (Hemiptera: Reduviidae: Triatominae) is associated with housing characteristics in rural Mexico.

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    Cohen, Justin M; Wilson, Mark L; Cruz-Celis, Adriana; Ordoñez, Rosalinda; Ramsey, Janine M

    2006-11-01

    Long-term control of Chagas disease requires not only interruption of the human transmission cycle of Trypanosoma cruzi Schyzotrypanum, Chagas, 1909 by controlling its domestic triatomine vectors but also surveillance to prevent reinfestation of residences from sylvatic or persistent peridomestic populations. Although a number of potential risk factors for infestation have been implicated in previous studies, the explanatory power of resulting models has been low. Two years after cessation of triatomine vector control efforts in the town of Chalcatzingo, Morelos, 78 environmental, socioecological, and spatial variables were analyzed for association with infestation by Triatoma pallidipennis Stal 1872 (Hemiptera: Reduviidae: Triatominae), the principal vector of T. cruzi. We studied 712 residences in this rural community to identify specific intradomestic and peridomestic risk factors that predicted infestation with T. pallidipennis. From numerous characteristics that were identified as correlated with infestation, we derived multivariate logistic regression models to predict residences that were more or less likely to be infested with T. pallidipennis. The most important risk factors for infestation included measurements of house age, upkeep, and spatial location in the town. The effects of certain risk factors on infestation were found to be modified by spatial characteristics of residences. The results of this study provide new information regarding risk factors for infestation by T. pallidipennis that may aid in designing sustainable disease control programs in rural Mexico.

  19. Triatoma boliviana sp. n. (Hemiptera: Reduviidae: Triatominae) de los valles subandinos de La Paz - Bolivia, similar a Triatoma nigromaculata Stål, 1859

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    Martinez Avandano, Eddy; Chávez Espada, Tamara; Sossa Gil, Dino; Aranda Asturizaga, Roberto; Vargas Mamani, Benigno; Vidaurre Pietro, Pablo

    2007-01-01

    International audience; Triatoma bolivianasp. n. (Hemiptera: Reduviidae: Triatominae) from Sub Andean valleys of La Paz - Bolivia, related to Triatoma nigromaculata Stål, 1859. We present the description of Triatoma boliviana sp. n. based on morphological external characters of 3 males and 3 females following the keys of Lent and Wygodzinsky (1979) and Carcavallo et al. (1997). The new species are very similar to Triatoma nigromaculata and was captured in Sub Andean valleys from Muñecas Provi...

  20. Feeding behaviour of Belminus ferroae (Hemiptera: Reduviidae), a predaceous Triatominae colonizing rural houses in Norte de Santander, Colombia.

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    Sandoval, C M; Ortiz, N; Jaimes, D; Lorosa, E; Galvão, C; Rodriguez, O; Scorza, J V; Gutiérrez, R

    2010-06-01

    Belminus ferroae (Hemiptera: Reduviidae) was collected from houses in the localities of San Alberto and Santa Catalina in the municipality of Toledo, Department of Norte de Santander, Colombia. Precipitin tests revealed that the main hosts of B. ferroae are insects belonging to the order Blattodea, whose haemolymph serves as food (89.43%). A low rate of haematophagy was indicated on rodents, dogs and humans (7.32%) and no natural infection with Trypanosoma cruzi was found by either microscopic examination or polymerase chain reaction. The finding of B. ferroae inside houses, feeding primarily on Blattodea with only a minor tendency to feed on vertebrate blood, is indicative of both the evolutionary path from predator to blood-sucker taken by Triatominae and their tendency to adapt from silvatic to domestic habitats.

  1. Study of the external female genitalia of 14 Rhodnius species (Hemiptera, Reduviidae, Triatominae) using scanning electron microscopy

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    2014-01-01

    Background Among the vectors of Chagas disease (Hemiptera: Reduviidae:Triatominae), there are eighteen Rhodnius species described and some are difficult to identify. The aim of this article is to contribute to the specific identification of fourteen Rhodnius spp. through morphological characters of the external female genitalia. Methods Female abdomens were cut transversely. The specimens were then prepared for examination by using scanning electron microscopy. Results The careful examination of the dorsal, posterior and ventral sides revealed characteristics that allowed the identification of each of the fourteen species. Conclusion The use of external female genitalia as characteristics are proposed as a tool for specifically identifying Rhodnius species, and an identification key for these species is presented. PMID:24405517

  2. Morphological evidence suggests homoploid hybridization as a possible mode of speciation in the Triatominae (Hemiptera, Heteroptera, Reduviidae).

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    Costa, Jane; Peterson, A Townsend; Dujardin, Jean Pierre

    2009-03-01

    All known significant insect vectors of Trypanosoma cruzi are members of the Reduviidae, subfamily Triatominae. Infections with this parasite are the cause of Chagas disease, the single most costly parasitic disease in the Western Hemisphere. The Triatominae are almost completely restricted to the Americas, with >130 species distributed in several foci of species richness and endemism; nevertheless, the processes involved in the diversification of this group remain poorly understood. The Triatoma brasiliensis species complex was recently proposed based on geography, morphology, ecology, and molecular data, and is believed to comprise two species and two subspecies. Here, we report results from a broad series of studies, in which first-generation offspring of experimental crosses were studied in terms of wing morphometry and phylogenetic position. Morphometrics, morphological, ecological and geographic analyses were consistent with the hypothesis of T. brasiliensis macromelasoma as a product of hybridization between two others (T. brasiliensis brasiliensis and T. juazeirensis). Although evidence is supportive of the hypothesis of speciation via hybridization as a mode of triatomine diversification, the case is not as-yet conclusive, and confirmation via molecular markers is necessary.

  3. Estudo morfométrico do gênero Panstrongylus Berg, 1879 (Hemiptera, Reduviidae, Triatominae Morphometric study of the genus Panstrongylus Berg, 1879 (Hemiptera, Reduviidae, Triatominae

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    Carolina Magalhães dos Santos

    2003-10-01

    Full Text Available The subfamily Triatominae is actually represented by 137 species distributed among 6 tribes and 19 genera. Within this subfamily, the genus Panstrongylus, Berg 1879, is composed by 13 species widespread in sylvatic, peridomestic, and domestic habitats of Neotropical regions. These species are vectors of Chagas disease and consequently are found associated with its main hosts, such as birds and mammals. Interest in species of this genus has been increasing in the last few years. Reports of several authors indicate these Triatominae to invade and colonize houses, increasing their epidemiological significance. Morphometry was used in this study to investigate correlations among possible closely related species. We measured 224 specimens among 13 species through a set of metric variables of the head. The results indicated that the genus Panstrongylus seems to be homogeneous since 10 of the 14 species were shown to be closely related.

  4. Description of the male genitalia of Belminus rugulosus Stål and Belminus corredori Galvão & Angulo, and comments on the holotype of Parabelminus yurupucu Lent & Wygodzinsky (Hemiptera: Heteroptera: Reduviidae: Triatominae: Bolboderini).

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    Gil-Santana, Hélcio R; Galvão, Cleber

    2013-12-13

    The male genitalia of Belminus rugulosus Stål and Belminus corredori Galvão & Angulo are described and illustrated for the first time. Comments on the holotype of Parabelminus yurupucu Lent & Wygodzinsky are presented (Hemiptera: Heteroptera: Reduviidae: Triatominae: Bolboderini). A discussion on previous data in the literature on male genitalia of species of Belminus Stål is provided.

  5. Community-based sampling methods for surveillance of the Chagas disease vector, Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    Weeks, E N I; Davies, C; Rosales, C Cordón; Yeo, M; Gezan, S A; Parra-Henao, G; Cameron, M M

    2014-09-01

    In Guatemala, the most widespread vector of Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae), the causative agent of Chagas disease, is Triatoma dimidiata (Latreille) (Hemiptera: Reduviidae: Triatominae). T. dimidiata is native to Guatemala and is present in both domestic and sylvatic habitats. Consequently, control of T. dimidiata is difficult because after successful elimination from homes, individual insects can recolonize homes from the surrounding environment. Therefore, intensive long-term surveillance of this species is essential to ensure adequate control is achieved. Manual inspection for signs of infestation, the current method used to monitor Triatominae throughout Central and South America, is labor and time-consuming, so cost-effective alternatives are needed. The current study compared the effectiveness of the current method of surveillance of T. dimidiata with community-based techniques of G6mez-Nuñez sensor boxes, collection and observation of bugs by householders, and presence of triatomine-like feces on walls. Although manual inspection was the most sensitive method when used alone, collection by householders also was sensitive and specific and involved less effort. Sensor boxes were not sensitive indicators of T. dimidiata infestation when used alone. Two recorded variables, visual inspection for feces and the sighting of bugs by householders, were sensitive and specific indicators of infestation, and in combination with collection by householders and sensor boxes these methods were significantly more likely to detect infestations than manual inspection alone. A surveillance program that combines multiple community-based techniques should have low cost and involve minimal effort from the government and at the same time promote sustainable community involvement in disease prevention.

  6. Importance of species of Triatominae (Heteroptera: Reduviidae) in risk of transmission of Trypanosoma cruzi in western Mexico.

    Science.gov (United States)

    Martínez-Ibarra, J A; Grant-Guillén, Y; Morales-Corona, Z Y; Haro-Rodríguez, S; Ventura-Rodríguez, L V; Nogueda-Torres, B; Bustos-Saldaña, R

    2008-05-01

    The epidemiological risk of infection by Trypanosoma cruzi Chagas in human populations of western Mexico is still under study. Although most vectors in this region and their vector capability are already known, new studies estimating the risk and the importance of individual Triatominae species (Hemiptera: Reduviidae) for T. cruzi transmission are necessary. For 1 yr, every month, > 400 human dwellings and their surroundings in eight communities of two western Mexico states were searched for triatomines. More than 1,000 specimens representing four species were collected and checked for T. cruzi infection. Based on the usual entomological indices, only the inhabitants of Gavilán El Progreso-La Villita are at serious risk of vectorial infection by T. cruzi. A population of Meccus longipennis (Usinger) was found living in peridomestic rock pile boundary walls after an insecticide spraying. It was confirmed the major role of peridomestic habitats as shelter areas for triatomines, particularly in rock pile boundary walls and chicken roosts. Triatominae presence also was verified in certain sylvatic habitats, including primarily heaps of stones. The important role of M. longipennis in the potential transmission of T. cruzi in the region and the secondary role of M. picturatus (Usinger) and Triatoma barberi Usinger also were confirmed. Null colonization of houses by T. barberi, which was collected primarily in peridomestic habitats, differs from its common intradomiciliary collection in other studies. Meccus pallidipennis (Stål) most probably does not exist in Nayarit. Meccus mazzottii (Usinger) and Meccus phyllosomus (Burmeister) are no longer found in Nayarit and Jalisco. Additional studies are necessary to determine the current epidemiological situation in other areas of western Mexico.

  7. Phylogeny and niche conservatism in North and Central American triatomine bugs (Hemiptera: Reduviidae: Triatominae), vectors of Chagas' disease.

    Science.gov (United States)

    Ibarra-Cerdeña, Carlos N; Zaldívar-Riverón, Alejandro; Peterson, A Townsend; Sánchez-Cordero, Víctor; Ramsey, Janine M

    2014-10-01

    The niche conservatism hypothesis states that related species diverge in niche characteristics at lower rates than expected, given their lineage divergence. Here we analyze whether niche conservatism is a common pattern among vector species (Hemiptera: Reduviidae: Triatominae) of Trypanosoma cruzi that inhabit North and Central America, a highly heterogeneous landmass in terms of environmental gradients. Mitochondrial and nuclear loci were used in a multi-locus phylogenetic framework to reconstruct phylogenetic relationships among species and estimate time of divergence of selected clades to draw biogeographic inferences. Then, we estimated similarity between the ecological niche of sister species and tested the niche conservatism hypothesis using our best estimate of phylogeny. Triatoma is not monophyletic. A primary clade with all North and Central American (NCA) triatomine species from the genera Triatoma, Dipetalogaster, and Panstrongylus, was consistently recovered. Nearctic species within the NCA clade (T. p. protracta, T. r. rubida) diverged during the Pliocene, whereas the Neotropical species (T. phyllosoma, T. longipennis, T. dimidiata complex) are estimated to have diverged more recently, during the Pleistocene. The hypothesis of niche conservatism could not be rejected for any of six sister species pairs. Niche similarity between sister species best fits a retention model. While this framework is used here to infer niche evolution, it has a direct impact on spatial vector dynamics driven by human population movements, expansion of transportation networks and climate change scenarios.

  8. Perfil electroforético de proteínas presentes en la saliva de Triatoma dimidiata (Hemiptera: Reduviidae:Triatominae Electrophoretic profile of salivary proteins of Triatoma dimidiata (Hemiptera: Reduviidae:Triatominae

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    Mónica Flórez

    2009-08-01

    Full Text Available Introducción: Los triatominos (Hemiptera: Reduviidae:Triatominae son insectos hematófagos que secretan una saliva rica en proteínas con propiedades anticoagulantes, antihistamínicas, vasodilatadoras y antiplaquetarias que facilitan su proceso de alimentación en el huésped vertebrado y favorecen la transmisión a éste de los protozoarios que se desarrollan en sus glándulas salivales. Estas proteínas son características de cada especie de triatomino y pueden ayudar a diferenciar especies, incluso aquellas fenotípicamente similares. Objetivo: Describir los perfiles electroforéticos de las proteínas salivales de Triatoma dimidiata encontrados en el intradomicilio, peridomicilio y extradomicilio en un área endémica en Santander. Materiales y métodos: Se disectaron las glándulas salivales de insectos adultos de T. dimidiata de tres municipios de Santander procedentes de colonias de laboratorio y de campo. Los perfiles de proteínas se visualizaron realizando una electroforesis de una dimensión en geles de poliacrilamida tenidos con azul de Coomassie. Resultados: Los perfiles electroforéticos de las proteínas presentes en la saliva de T. dimidiata muestran hasta 33 bandas en el rango de 23,7 a 228,8 kDa, con una alta concentración en la región 41 a 99,7 kDa. El índice de polimorfismo para T. dimidiata fue de 0,9646. Conclusión: El perfil electroforético de las proteínas salivares de T. dimidiata mostró una composición proteica compleja, donde las bandas más prominentes tienen pesos moleculares menores de 45 KDa. No se pudieron establecer agrupamientos basados en las regiones geográficas y lugares de captura, a pesar de la gran variabilidad intraespecífica observada. Sin embargo, se pudieron establecer diferencias claras a nivel de especie entre T. dimidiata y el grupo externo utilizado, P. geniculatus. Salud UIS 2009; 41: 121-127.Introduction: The triatomines (Heteroptera, Reduviidae, Triatominae are hematophagous insects

  9. Triatominae species of Suriname (Heteroptera: Reduviidae) and their role as vectors of Chagas disease

    OpenAIRE

    Hiwat, Hélène

    2014-01-01

    Nine species of Triatominae, representing three tribes and five genera, are currently known in Suriname. An annotated list of the species based on the collections of the Bureau of Public Health (Suriname), the National Zoological Collection Suriname and the National History Museum Leiden (the Netherlands) is provided. Additionally, the results of several years of opportunistic collection in two domestic environments are presented. The most common species are Rhodnius pictipes Stål, 1972,...

  10. Large-scale patterns in morphological diversity and species assemblages in Neotropical Triatominae (Heteroptera: Reduviidae).

    Science.gov (United States)

    Fergnani, Paula Nilda; Ruggiero, Adriana; Ceccarelli, Soledad; Menu, Frédéric; Rabinovich, Jorge

    2013-12-01

    We analysed the spatial variation in morphological diversity (MDiv) and species richness (SR) for 91 species of Neotropical Triatominae to determine the ecological relationships between SR and MDiv and to explore the roles that climate, productivity, environmental heterogeneity and the presence of biomes and rivers may play in the structuring of species assemblages. For each 110 km x 110 km-cell on a grid map of America, we determined the number of species (SR) and estimated the mean Gower index (MDiv) based on 12 morphological attributes. We performed bootstrapping analyses of species assemblages to identify whether those assemblages were more similar or dissimilar in their morphology than expected by chance. We applied a multi-model selection procedure and spatial explicit analyses to account for the association of diversity-environment relationships. MDiv and SR both showed a latitudinal gradient, although each peaked at different locations and were thus not strictly spatially congruent. SR decreased with temperature variability and MDiv increased with mean temperature, suggesting a predominant role for ambient energy in determining Triatominae diversity. Species that were more similar than expected by chance co-occurred near the limits of the Triatominae distribution in association with changes in environmental variables. Environmental filtering may underlie the structuring of species assemblages near their distributional limits.

  11. Descrição de ovos e ninfas de Triatoma klugi (Hemiptera, Reduviidae, Triatominae Description of eggs and nymphs of Triatoma klugi (Hemiptera, Reduviidae, Triatominae

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    José Jurberg

    ópolis, in the State of Rio Grande do Sul. The local of capture of the Triatominae is placed enters 700 and 800 m of altitud (29º18'38''S, 51º04'57''W. Together with T. oliveirai (Neiva, Pinto & Lent, 1939, its morphologically related species, is the only ones of the complex that had not been found, until the moment, in the State of Mato Grosso, Mato Grosso do Sul and Goiás, Brazil. In experimental conditions, already it was tested and proven its susceptibilities to the infection for Trypanosoma cruzi (Chagas, 1909 and Trypanosoma rangeli (Tejera, 1920. The comparative analysis of the ornaments of the exocorium of eggs and of three nymphs of T. klugi by optic microscopy and scanning electron microscopy showed some morphologic particularities, with prominence for: the ventral face of the head, the stridulatory sulcus and the last abdominal segments (IX, X - future genitalia and XI - anal duct. These data contribute for the magnifying of the distinguishing parameters aiming at diagnosis of T. klugi during its nymphal development.

  12. First report of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in the State of Acre, Brazil.

    Science.gov (United States)

    Meneguetti, Dionatas Ulises de Oliveira; Tojal, Simone Delgado; Miranda, Pedro Raimundo Mathias de; Rosa, João Aristeu da; Camargo, Luis Marcelo Aranha

    2015-01-01

    This paper reports, for the first time, the presence of Rhodnius montenegrensis in the State of Acre, Brazil. Two female R. montenegrensis were collected in a dwelling in the rural area of Rio Branco, Acre, Brazil. The occurrence of this species was confirmed, and the number of Triatominae species in the State of Acre increased from four to five. Further studies should be performed to reach a clearer understanding of the ecology of this arthropod, its possible role in transmitting Chagas' disease and rangeliosis, and its current geographical distribution in the region.

  13. Triatominae species of Suriname (Heteroptera: Reduviidae) and their role as vectors of Chagas disease

    Science.gov (United States)

    Hiwat, Hélène

    2014-01-01

    Nine species of Triatominae, representing three tribes and five genera, are currently known in Suriname. An annotated list of the species based on the collections of the Bureau of Public Health (Suriname), the National Zoological Collection Suriname and the National History Museum Leiden (the Netherlands) is provided. Additionally, the results of several years of opportunistic collection in two domestic environments are presented. The most common species are Rhodnius pictipes Stål, 1972, Rhodnius robustus Larrouse, 1972 and Panstrongylus geniculatus (Latreille, 1811). The significance of the species as vectors of Chagas disease in Suriname is discussed. PMID:25004146

  14. Morphology of the spermathecae of twelve species of Triatominae (Hemiptera, Reduviidae) vectors of Chagas disease.

    Science.gov (United States)

    Nascimento, Juliana Damieli; Ribeiro, Aline Rimoldi; Almeida, Larissa Aguiar; de Oliveira, Jader; Mendonça, Vagner José; Cilense, Mário; da Rosa, João Aristeu

    2017-12-01

    Trypanosoma cruzi, the etiological agent of Chagas disease, is transmitted by triatomines that have been described in a large number of studies. Most of those studies are related to external morphology and taxonomy, but some biochemical, genetic and physiological studies have also been published. There are a few publications in the literature about the internal organs of Triatominae, for instance the spermathecae, which are responsible for storing and maintaining the viability of the spermatozoids until the fertilization of the oocytes. This work aims to study the spermathecae of twelve species of triatomines obtained from the Triatominae Insectarium of the Faculty of Pharmaceutical Sciences, UNESP, Araraquara, using optical microscopy and scanning electron microscopy. The spermathecae of the twelve species studied showed three morphological patterns: a) P. herreri sn, P. lignarius, P. megistus, Triatoma brasiliensis, T. juazeirensis, T. sherlocki and T. tibiamaculata have spermathecae with a thin initial portion and an oval-shaped final portion; b) R. montenegrensis, R. nasutus, R. neglectus, R. pictipes and R. prolixus have tubular and winding spermathecae; c) T. infestans has oval spermathecae. In addition to the three morphological patterns, it was noted that each of the twelve species has particular features that differentiate them. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Levantamento da fauna de Triatominae (Hemiptera: Reduviidae em ambiente domiciliar e infecção natural por Trypanosomatidae no Estado de Mato Grosso do Sul Survey of Triatominae (Hemiptera: Reduviidae fauna in domestic environments and natural infection by Trypanosomatidae in the State of Mato Grosso do Sul

    Directory of Open Access Journals (Sweden)

    Paulo Silva de Almeida

    2008-08-01

    Full Text Available Entre 2000 a 2004, foi realizado levantamento da fauna de Triatominae (Hemiptera: Reduviidae e exame de infecção natural por Trypanosomatidae, no Estado de Mato Grosso do Sul. Um total de 13.671 espécimes foram capturados. Na análise faunística das espécies capturadas, Triatoma sordida foi caracterizada como muito abundante, muito freqüente, constante e dominante. Os índices de infecção natural para Trypanosoma cruzi apresentaram os valores de 3,2% para Panstrongylus geniculatus, 0,6% para Rhodnius neglectus e 0,1% para Triatoma sordida, apesar do Estado de Mato Grosso do Sul apresentar-se livre da transmissão vetorial endêmica.Between 2000 and 2004, a survey of Triatominae fauna (Hemiptera: Reduviidae and examination of natural infection caused by Trypanosomatidae in the State of Mato Grosso do Sul, Brazil, was conducted. A total of 13,671 specimens were collected. Through fauna analysis on the insects that were caught, Triatoma sordida was characterized as very abundant, very frequent, constant and dominant. The rates of natural infection with Trypanosoma cruzi were 3.2% for Panstrongylus geniculatus, 0.6% for Rhodnius neglectus and 0.1% for Triatoma sordida. Nevertheless, the State of Mato Grosso do Sul is free from endemic vector transmission.

  16. Potential Distribution of Chagas Disease Vectors (Hemiptera, Reduviidae, Triatominae) in Colombia, Based on Ecological Niche Modeling.

    Science.gov (United States)

    Parra-Henao, Gabriel; Suárez-Escudero, Laura C; González-Caro, Sebastián

    2016-01-01

    Ecological niche modeling of Triatominae bugs allow us to establish the local risk of transmission of the parasite Trypanosoma cruzi, which causes Chagas disease. This information could help to guide health authority recommendations on infection monitoring, prevention, and control. In this study, we estimated the geographic distribution of triatomine species in Colombia and identified the relationship between landscape structure and climatic factors influencing their occurrence. A total of 2451 records of 4 triatomine species ( Panstrongylus geniculatus , Rhodnius pallescens , R. prolixus , and Triatoma maculata ) were analyzed. The variables that provided more information to explain the ecologic niche of these vectors were related to precipitation, altitude, and temperature. We found that the species with the broadest potential geographic distribution were P. geniculatus , R. pallescens , and R. prolixus . In general, the models predicted the highest occurrence probability of these vectors in the eastern slope of the Eastern Cordillera, the southern region of the Magdalena valley, and the Sierra Nevada of Santa Marta.

  17. Potential Distribution of Chagas Disease Vectors (Hemiptera, Reduviidae, Triatominae) in Colombia, Based on Ecological Niche Modeling

    Science.gov (United States)

    Suárez-Escudero, Laura C.; González-Caro, Sebastián

    2016-01-01

    Ecological niche modeling of Triatominae bugs allow us to establish the local risk of transmission of the parasite Trypanosoma cruzi, which causes Chagas disease. This information could help to guide health authority recommendations on infection monitoring, prevention, and control. In this study, we estimated the geographic distribution of triatomine species in Colombia and identified the relationship between landscape structure and climatic factors influencing their occurrence. A total of 2451 records of 4 triatomine species (Panstrongylus geniculatus, Rhodnius pallescens, R. prolixus, and Triatoma maculata) were analyzed. The variables that provided more information to explain the ecologic niche of these vectors were related to precipitation, altitude, and temperature. We found that the species with the broadest potential geographic distribution were P. geniculatus, R. pallescens, and R. prolixus. In general, the models predicted the highest occurrence probability of these vectors in the eastern slope of the Eastern Cordillera, the southern region of the Magdalena valley, and the Sierra Nevada of Santa Marta. PMID:28115946

  18. Insects found in birds' nests from Argentina. Pseudoseisura lophotes Reichenbach, 1853 and Anumbius annumbi (Vieillot, 1817) (Aves: Furnariidae), hosts of Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    Paola, Turienzo

    2014-02-24

    The insect fauna of the nests of Pseudoseisura lophotes (Reichenbach, 1853) (Aves: Furnariidae) from Argentina was investigated. A total of 110 species (68 identified to species, 22 identified to genus, 20 identified to family) in 40 families of 10 orders of insects was found in these nests. Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae) was found again in nests of P. lophotes, corroborating after 73 years the first observations made by Mazza in 1936. The occurrence of the insects in nests of P. lophotes is compared with the previously known insect fauna in nests of A. annumbi, Furnarius rufus (Furnariidae), and Myiopsitta monachus (Psittacidae). The insect fauna in additional nests of Anumbius annumbi from the same and/or different localities is given, and used in comparisons. The first occurrence of Cuterebridae (Diptera) in birds' nests, their pupae as the overwintering stage, and the second simultaneous infestation by two species of Philornis (Diptera: Muscidae) on the same nestlings are presented. Other simultaneous infestations of different hematophagous arthropods (Hemiptera: Cimidae; Reduviidae: Triatominae, and Acari: Argasidae) are remarked and discussed.

  19. Biological aspects of crosses between Triatoma recurva (Stål), 1868 (Hemiptera: Reduviidae: Triatominae) and other members of the Phyllosoma complex.

    Science.gov (United States)

    Martínez-Ibarra, José Alejandro; Nogueda-Torres, Benjamín; Licón-Trillo, Ángel; Alejandre-Aguilar, Ricardo; Salazar-Schettino, Paz María; Vences-Blanco, Mauro Omar

    2015-06-01

    The degree of reproductive isolation between Triatoma recurva (Stål) (Hemiptera: Reduviidae: Triatominae) and the six species of the genus Meccus plus T. mexicana (Herrich-Schaeffer) (Hemiptera: Reduviidae) was examined. Fertility and the segregation of morphological characteristics were examined in two generations of hybrids from crosses between these species. The percentage of couples with offspring (fertile) was low in the vast majority of sets of crosses, with the exception of that between T. recurva female and M. phyllosomus male. In all studied sets of crosses, no first- (F1) or second- (F2) generation individuals were morphologically similar to T. recurva but instead shared the morphology of the other parental species. A similar phenomenon was observed in the three successful sets of backcrosses. These results indicated that different recorded levels of reproductive fitness among T. recurva and the species of Meccus involved in this study, plus T. mexicana, are present and that they were apparently influenced by differing mechanisms of isolation. The presence of some degree of reproductive compatibility between studied triatomines of distinct genera (Meccus spp. and Triatoma spp.) reinforces the need for generic revision of the tribe Triatomini. © 2015 The Society for Vector Ecology.

  20. Atlas of Mexican Triatominae (Reduviidae: Hemiptera) and vector transmission of Chagas disease

    Science.gov (United States)

    Ramsey, Janine M; Peterson, A Townsend; Carmona-Castro, Oscar; Moo-Llanes, David A; Nakazawa, Yoshinori; Butrick, Morgan; Tun-Ku, Ezequiel; de la Cruz-Félix, Keynes; Ibarra-Cerdeña, Carlos N

    2015-01-01

    Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs) were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission. PMID:25993505

  1. Atlas of Mexican Triatominae (Reduviidae: Hemiptera) and vector transmission of Chagas disease.

    Science.gov (United States)

    Ramsey, Janine M; Peterson, A Townsend; Carmona-Castro, Oscar; Moo-Llanes, David A; Nakazawa, Yoshinori; Butrick, Morgan; Tun-Ku, Ezequiel; la Cruz-Félix, Keynes de; Ibarra-Cerdeña, Carlos N

    2015-05-01

    Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs) were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission.

  2. Karyosystematics of Triatoma rubrofasciata (De Geer, 1773) (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    Alevi, Kaio Cesar Chaboli; Borsatto, Kelly Cristine; Moreira, Felipe Ferraz Figueiredo; Jurberg, José; De Azeredo-Oliveir, Maria Tercília Vilela

    2015-08-03

    Triatoma rubrofasciata (De Geer) is the first species of triatomine described, and little is known on its vector biology. Studies are restricted to starvation resistance, interspecific morphometric variability, morphometry of testis follicles, coloration of the testicular peritoneal sheath, ultrastructure of the male accessory glands, phylogeny and cytogenetics. Thus, this study aims to address the karyosystematics of T. rubrofasciata and the possible events related to karyotype evolution of this species. Four adult males were analyzed cytogenetically. The analysis of meiotic metaphases of T. rubrofasciata allowed to confirm the karyotype of species, out more, 2n = 25 (22A + X1X2Y). This number is very important for taxonomic and evolutionary inferences on the species, because of the 88 triatomine species with described karyotype, only T. rubrofasciata exhibits 25 chromosomes. Based on the hypothesis of the karyotype 2n = 22 (20A + XY) as ancestral for triatomines, we propose three evolutionary hypotheses for the emergence of the karyotype of T rubrofasciata, all supported by agmatoploidy events (fission). Basically the hypotheses are 1) fission for a pair of autosomes, resulting in 22 autosomes and later fission of sex chromosome X; 2) fission of pair of autosomes and the sex chromosome X concomitantly; 3) fission of sex chromosome X and subsequently fission of pair of autosomes. Thus, this study highlights for the first time the importance of the number of chromosomes of T. rubrofasciata as characteristic diagnosis in Triatominae subfamily and describes three evolutionary hypotheses that possibly led the emergence of karyotype of this insect of global importance.

  3. External female genitalia of six species of the genus Meccus (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    Rivas, Nancy; Sánchez-Cordero, Victor; Camacho, Alejandro D; Alejandre-Aguilar, Ricardo

    2017-12-01

    Triatomine classification is based on morphological characteristics. Studies have been conducted to improve their identification by observing many characteristics. However, there are problems of differentiating among highly interrelated species and new criteria are required. The purpose of this study was to determine the morphological differences in the external female genitalia of M. pallidipennis, M. longipennis, M. picturatus, M. bassolsae, M. mazzottii, and M. phyllosomus in order to distinguish among species using scanning electron microscopy. Observations were made of the dorsal, posterior, lateral, and ventral views of the female external genitalia for each species. In the six species we studied, relevant differences were observed in the dorsal view of the X segment, as well as the IX, VIII, and VII tergites. In the posterior and lateral view, the most visible differences were registered in the gonocoxite size of the segments VIII, IX, and X. Finally, in the ventral view of the VII sternite, differences among species were observed in the size of the inflection in the top and upper corner. Our results show that it was possible to differentiate among the triatominae species for each of the four views by using a scanning electron microscope to analyze morphological characteristics of the VII, VIII, IX, and X abdomen segments. © 2017 The Society for Vector Ecology.

  4. Atlas of Mexican Triatominae (Reduviidae: Hemiptera and vector transmission of Chagas disease

    Directory of Open Access Journals (Sweden)

    Janine M Ramsey

    2015-05-01

    Full Text Available Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission.

  5. Holocentric chromosome evolution in kissing bugs (Hemiptera: Reduviidae: Triatominae): diversification of repeated sequences.

    Science.gov (United States)

    Pita, Sebastián; Lorite, Pedro; Vela, Jesús; Mora, Pablo; Palomeque, Teresa; Thi, Khoa Pham; Panzera, Francisco

    2017-09-06

    The analysis of the chromosomal and genome evolution in organisms with holocentric chromosomes is restricted by the lack of primary constriction or centromere. An interesting group is the hemipteran subfamily Triatominae, vectors of Chagas disease, which affects around 6 to 7 million people worldwide. This group exhibits extensive variability in the number and chromosomal location of repeated sequences such as heterochromatin and ribosomal genes. This paper tries to reveal the significant differences of the repeated sequences among Triatoma species through the use of genomic DNA probes. We analysed the chromosomal distribution and evolution of repeated sequences in Triatoma species by genomic in situ hybridization (GISH) using genomic DNA probes from two North American Triatoma species. These genomic probes were hybridized both on their own chromosomes and on other Triatoma species from North and South America, with different amounts and chromosome location of C-heterochromatin. The results were compared with those previously described using South American Triatoma genomic probes. We observed two chromosomal hybridization patterns: (i) very intense hybridization signals concentrated on specific chromosomal regions or particular chromosomes; and (ii) lower intensity hybridization signals dispersed along all chromosomes. Self-GISH on T. rubrofasciata and T. dimidiata chromosomes presented strong hybridization signals on all C-heterochromatin regions. However, when we perform genomic cross-hybridizations, only strong signals are detected on the Y chromosome, leaving the C-heterochromatic autosomal regions unmarked. We confirm that repeated DNA of the Y chromosome is shared among Triatoma species and probably represents an ancestral character of the Triatomini tribe. On the contrary, autosomal heterochromatic regions are constituted by species-specific DNA repeats, most probably satDNA families, suggesting that Triatoma speciation involved the amplification of diverse

  6. Nuclear rDNA-based molecular clock of the evolution of triatominae (Hemiptera: Reduviidae, vectors of Chagas disease

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    Bargues MD

    2000-01-01

    Full Text Available The evolutionary history and times of divergence of triatomine bug lineages are estimated from molecular clocks inferred from nucleotide sequences of the small subunit SSU (18S and the second internal transcribed spacer (ITS-2 of the nuclear ribosomal DNA of these reduviids. The 18S rDNA molecular clock rate in Triatominae, and Prosorrhynchan Hemiptera in general, appears to be of 1.8% per 100 million years (my. The ITS-2 molecular clock rate in Triatominae is estimated to be around 0.4-1% per 1 my, indicating that ITS-2 evolves 23-55 times faster than 18S rDNA. Inferred chronological data about the evolution of Triatominae fit well with current hypotheses on their evolutionary histories, but suggest reconsideration of the current taxonomy of North American species complexes.

  7. Distribution and evolution of repeated sequences in genomes of Triatominae (Hemiptera-Reduviidae inferred from genomic in situ hybridization.

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    Sebastian Pita

    Full Text Available The subfamily Triatominae, vectors of Chagas disease, comprises 140 species characterized by a highly homogeneous chromosome number. We analyzed the chromosomal distribution and evolution of repeated sequences in Triatominae genomes by Genomic in situ Hybridization using Triatoma delpontei and Triatoma infestans genomic DNAs as probes. Hybridizations were performed on their own chromosomes and on nine species included in six genera from the two main tribes: Triatomini and Rhodniini. Genomic probes clearly generate two different hybridization patterns, dispersed or accumulated in specific regions or chromosomes. The three used probes generate the same hybridization pattern in each species. However, these patterns are species-specific. In closely related species, the probes strongly hybridized in the autosomal heterochromatic regions, resembling C-banding and DAPI patterns. However, in more distant species these co-localizations are not observed. The heterochromatic Y chromosome is constituted by highly repeated sequences, which is conserved among 10 species of Triatomini tribe suggesting be an ancestral character for this group. However, the Y chromosome in Rhodniini tribe is markedly different, supporting the early evolutionary dichotomy between both tribes. In some species, sex chromosomes and autosomes shared repeated sequences, suggesting meiotic chromatin exchanges among these heterologous chromosomes. Our GISH analyses enabled us to acquire not only reliable information about autosomal repeated sequences distribution but also an insight into sex chromosome evolution in Triatominae. Furthermore, the differentiation obtained by GISH might be a valuable marker to establish phylogenetic relationships and to test the controversial origin of the Triatominae subfamily.

  8. Phylogeny and biogeography of Triatominae (Hemiptera : Reduviidae): molecular evidence of a New World origin of the Asiatic clade

    Czech Academy of Sciences Publication Activity Database

    Hypša, Václav; Tietz, D. F.; Zrzavý, Jan; Rego, Ryan O. M.; Galvao, C.; Jurberg, J.

    2002-01-01

    Roč. 23, č. 3 (2002), s. 447-457 ISSN 1055-7903 R&D Projects: GA AV ČR IAA6022801 Institutional research plan: CEZ:AV0Z6022909 Keywords : Triatominae * phylogeny * biogeography Subject RIV: EG - Zoology Impact factor: 2.590, year: 2002

  9. Distribution and evolution of repeated sequences in genomes of Triatominae (Hemiptera-Reduviidae) inferred from genomic in situ hybridization.

    Science.gov (United States)

    Pita, Sebastian; Panzera, Francisco; Sánchez, Antonio; Panzera, Yanina; Palomeque, Teresa; Lorite, Pedro

    2014-01-01

    The subfamily Triatominae, vectors of Chagas disease, comprises 140 species characterized by a highly homogeneous chromosome number. We analyzed the chromosomal distribution and evolution of repeated sequences in Triatominae genomes by Genomic in situ Hybridization using Triatoma delpontei and Triatoma infestans genomic DNAs as probes. Hybridizations were performed on their own chromosomes and on nine species included in six genera from the two main tribes: Triatomini and Rhodniini. Genomic probes clearly generate two different hybridization patterns, dispersed or accumulated in specific regions or chromosomes. The three used probes generate the same hybridization pattern in each species. However, these patterns are species-specific. In closely related species, the probes strongly hybridized in the autosomal heterochromatic regions, resembling C-banding and DAPI patterns. However, in more distant species these co-localizations are not observed. The heterochromatic Y chromosome is constituted by highly repeated sequences, which is conserved among 10 species of Triatomini tribe suggesting be an ancestral character for this group. However, the Y chromosome in Rhodniini tribe is markedly different, supporting the early evolutionary dichotomy between both tribes. In some species, sex chromosomes and autosomes shared repeated sequences, suggesting meiotic chromatin exchanges among these heterologous chromosomes. Our GISH analyses enabled us to acquire not only reliable information about autosomal repeated sequences distribution but also an insight into sex chromosome evolution in Triatominae. Furthermore, the differentiation obtained by GISH might be a valuable marker to establish phylogenetic relationships and to test the controversial origin of the Triatominae subfamily.

  10. The nuclear elongation factor-1α gene: a promising marker for phylogenetic studies of Triatominae (Hemiptera: Reduviidae).

    Science.gov (United States)

    Díaz, Sebastián; Triana-Chávez, Omar; Gómez-Palacio, Andrés

    2016-09-01

    Molecular systematics is a remarkable approach for understanding the taxonomic traits and allows the exploration of the inter-population dynamics of several species in the Triatominae subfamily that are involved in Trypanosoma cruzi transmission. Compared to other relevant species that transmit vector-borne diseases, such as some species of the Diptera, there are relatively few nuclear genetic markers available for systematic studies in the Triatominae subfamily. Molecular systematic studies performed on Triatominae are based on mitochondrial gene fragments and, less frequently, on nuclear ribosomal genes or spacers. Due to the fact that these markers can occasionally present problems such as nuclear mitochondrial genes (NUMTs) or intra-genomic variation for high gene copy numbers, it is necessary to use additional nuclear markers to more reliably address the molecular evolution of Triatominae. In this study, we performed phylogenetic analysis using the nuclear elongation factor-1 alpha (EF-1α) gene in individuals from 12 species belonging to the Triatomini and Rhodniini tribes. Genetic diversities and phylogenetic topologies were compared with those obtained for the mitochondrial 16S rRNA and Cytochrome b (cyt b) genes, as well as for the D2 variable region of the ribosomal 28S rRNA gene. These results indicate that the EF-1α marker exhibits an intermediate level of diversity compared to mitochondrial and nuclear ribosomal genes, and that phylogenetic analysis based on EF-1α is highly informative for resolving deep phylogenetic relationships in Triatominae, such as tribe or genera. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Susceptibility and resistance to deltamethrin of wild and domestic populations of Triatoma infestans (Reduviidae: Triatominae in Bolivia: new discoveries

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    Stéphanie Depickère

    2012-12-01

    Full Text Available Bolivia is a high-endemic country for Chagas disease, for which the principal vector is Triatoma infestans (Triatominae. This is a mainly domestic species that is also found in the wild environment. Recently, an increasing number of studies have shown the importance of Triatominae resistance to insecticides, especially in Bolivia. Data regarding the susceptibility/resistance of wild and domestic populations of T. infestans to deltamethrin are presented. For the first time, domestic populations of the department of Santa Cruz were tested, showing low resistance. Although most of the wild populations were found to be susceptible to deltamethrin, three populations from three departments showed a mortality rate of less than 100%. This result is emphasised here.

  12. Description and characterization of the melanic morphotype of Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae

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    Fernando Braga Stehling Dias

    2014-10-01

    Full Text Available Introduction For the first time we provide the description of the melanic (dark morphotype of Rhodnius nasutus and determine the pattern of genetic inheritance for this characteristic. Methods Dark morph R. nasutus specimens were crossbred with standard (typically patterned R. nasutus. Results We present the first occurrence of the melanic morphotype in the genus Rhodnius. The crossbreeding results demonstrate that the inheritance pattern of this characteristic follows Mendel's simple laws of segregation and an independent assortment of alleles. Conclusions Phenotypic variation of R. nasutus reinforces the heterogeneity found in the Triatominae. Descriptions of new species in this subfamily require rigorous validation criteria.

  13. First report of Rhodnius stali (Hemiptera, Reduviidae, Triatominae) in the State of Acre and in the Brazilian Amazon.

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    Meneguetti, Dionatas Ulises de Oliveira; Castro, Gabriela Vieira de Souza; Castro, Mariane Albuquerque Lima Ribeiro; Souza, Janis Lunier de; Oliveira, Jader de; Rosa, João Aristeu da; Camargo, Luis Marcelo Aranha

    2016-01-01

    This paper reports, for the first time, the presence of Rhodnius stali in the state of Acre and in the Brazilian Amazon. Specimens of R. stali were collected by the Federal University of Acre in Rio Branco. The number of Triatominae species in the State of Acre increased from five to six. This was also the first report of R. stali in the Brazilian Amazon. The occurrence of R. stali is worrisome, since this species has been found naturally infected by Trypanosoma cruzi and there has been evidence of its domiciliation capabilities.

  14. First report of Panstrongylus lignarius , Walker, 1873 (Hemiptera, Reduviidae, Triatominae), in the State of Rondônia, Brazil.

    Science.gov (United States)

    Terassini, Flávio Aparecido; Stefanello, Carlise; Camargo, Luís Marcelo Aranha; Meneguetti, Dionatas Ulises de Oliveira

    2017-01-01

    This study reports, for the first time, the presence of Panstrongylus lignarius in the State of Rondonia, Brazil. Specimen of P. lignarius was collected from a flat in an urban area of the municipality of Porto Velho, Western Amazon. With this finding of P. lignarius, the number of Triatominae species in the State of Rondonia has increased from six to seven. The occurrence of P. lignarius is worrisome, because this species has been found to be naturally infected with Trypanosoma cruzi and there has been evidence of its domiciliation capabilities in other countries of South America.

  15. First report of Eratyrus mucronatus, Stal, 1859, (Hemiptera, Reduviidae, Triatominae), in the State of Rondônia, Brazil.

    Science.gov (United States)

    Meneguetti, Dionatas Ulises de Oliveira; Trevisan, Olzeno; Rosa, Renato Moreira; Camargo, Luís Marcelo Aranha

    2011-01-01

    This paper reports, for the first time, the presence of the Eratyrus mucronatus species in the State of Rondonia, Brazil. These specimens were caught by chance in the forest and later they were collected using luminous traps. After finding these specimens, the number of the Triatominae genera in Rondonia rose to four, while its species rose to seven. Complimentary studies will be conducted in order to allow for clearer understanding the ecology of this arthropod, its possible role in transmitting Chagas' disease and its current geographical distribution.

  16. First report of Eratyrus mucronatus, Stal, 1859, (Hemiptera, Reduviidae, Triatominae, in the State of Rondônia, Brazil

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    Dionatas Ulises de Oliveira Meneguetti

    2011-08-01

    Full Text Available INTRODUCTION: This paper reports, for the first time, the presence of the Eratyrus mucronatus species in the State of Rondonia, Brazil. METHODS: These specimens were caught by chance in the forest and later they were collected using luminous traps. RESULTS: After finding these specimens, the number of the Triatominae genera in Rondonia rose to four, while its species rose to seven. CONCLUSIONS: Complimentary studies will be conducted in order to allow for clearer understanding the ecology of this arthropod, its possible role in transmitting Chagas' disease and its current geographical distribution.

  17. First report of Rhodnius stali (Hemiptera, Reduviidae, Triatominae in the State of Acre and in the Brazilian Amazon

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    Dionatas Ulises de Oliveira Meneguetti

    2016-06-01

    Full Text Available Abstract: INTRODUCTION: This paper reports, for the first time, the presence of Rhodnius stali in the state of Acre and in the Brazilian Amazon. METHODS: Specimens of R. stali were collected by the Federal University of Acre in Rio Branco. RESULTS: The number of Triatominae species in the State of Acre increased from five to six. This was also the first report of R. stali in the Brazilian Amazon. CONCLUSIONS: The occurrence of R. stali is worrisome, since this species has been found naturally infected by Trypanosoma cruzi and there has been evidence of its domiciliation capabilities.

  18. Distribuição Geográfica e Dispersão Alti-latitudinal de Alguns Gêneros e Espécies da Tribo Triatomini Jeannel, 1919 (Hemiptera, Reduviidae, Triatominae

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    Galvão Cleber

    1998-01-01

    Full Text Available Geographical Distribution and Alti-latitudinal Dispersion of Some Genera and Species of the Tribe Triatomini Jeannel, 1919 (Hemiptera, Reduviidae, Triatominae - With the currently known distribution of genera and species of the tribe Triatomini Jeannel, 1919, maps and diagrams were prepared, showing the geographical area occupied by the species and their respective dispersion in grades of latitude and altitude. Two genera are not treated: Panstrongylus Berg, 1879, already published and Triatoma Laporte, 1832, that is being published partially in several articles. Genus Eratyrus Stal, 1859, has two species, while Dipetalogaster Usinger, 1939, Mepraia Mazza, Gajardo & Joerg, 1940, Paratriatoma Barber, 1938 and recently created genus Hermanlentia Jurberg & Galvão, 1997, have only one each. The study of these maps and diagrams permits a better knowledge about some ecological requirements of Chagas' disease vectors and detects gaps in the geographical distribution, where the species were not found but probably they could be prevalent

  19. Alguns aspectos da biologia de Triatoma pseudomaculata Corrêa & Espínola, 1964, em condições de laboratório (Hemiptera:Reduviidae:Triatominae

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    Teresa Cristina M Gonçalves

    1997-03-01

    Full Text Available Biology of Triatoma pseudomaculata Corrêa & Espínola, 1964, under Laboratory Conditions (Hemiptera:Reduviidae:Triatominae - Observations were made on the evolutive cycle of Triatoma pseudomaculata, held under laboratory conditions, fed weekly on bird (pigeon. Of 60 eggs obtained, only 34 nymphs reached the adult stage in a period of X(S=398±76 days. The following parameters were observed: the time immature stages took to develop from egg to adult emergence; the occurrence of the first meal; the time-lapse between the presenting of the blood-meal and the begining of feeding; time of feeding; amount of blood ingested; variation of weight 24 hr after the blood-meal and until the next blood-meal; and the defecation pattern. The experiment was carried out for 20 months, held in BOD incubator with the average of temperature and humidity of 28±1ºC and 80±5% RU, respectively

  20. Anatomy of the spermatophore in triatomines (Hemiptera, Reduviidae, Triatominae) and its applications to the study of Chagas disease vector biology.

    Science.gov (United States)

    Pereira-Lourenço, Ariane S; Santos-Mallet, Jacenir R; Freitas, Simone P C

    2013-10-01

    The present study focused on spermatophore structure, transfer, and subsequent destination inside bloodfeeding females of the species Triatoma infestans and Rhodnius neglectus. The morphology of the spermatophore differed between the species studied, such that in T. infestans, the shape was ovaloid, whereas in R. neglectus, the shape resembled a rod. Structures' spine-like cuticulars distributed across the inner surface of the vagina of both species were observed; however, the role of these cuticulars is unknown in Triatominae. In both species, there was an opening in the spermatophore exactly where the common oviduct is connected, thereby making it possible to confirm that the process of spermatozoid migration takes place through this opening. The results obtained show that the spermatophores of T. infestans and R. neglectus differ in size, shape, and structure. Therefore, they can be used as taxonomic markers and may provide information regarding physiology and evolution.

  1. Detection of a Potential New Bartonella Species "Candidatus Bartonella rondoniensis" in Human Biting Kissing Bugs (Reduviidae; Triatominae).

    Science.gov (United States)

    Laroche, Maureen; Berenger, Jean-Michel; Mediannikov, Oleg; Raoult, Didier; Parola, Philippe

    2017-01-01

    Among the Reduviidae family, triatomines are giant blood-sucking bugs. They are well known in Central and South America where they transmit Trypanosoma cruzi to mammals, including humans, through their feces. This parasitic protozoan is the causative agent of Chagas disease, a major public health issue in endemic areas. Because of the medical and economic impact of Chagas disease, the presence of other arthropod-borne pathogens in triatomines was rarely investigated. In this study, seven triatomines species involved in the transmission of T. cruzi were molecularly screened for the presence of known pathogens generally associated with arthropods, such as Rickettsia, Bartonella, Anaplasmataceae, Borrelia species and Coxiella burnetii. Of all included triatomine species, only Eratyrus mucronatus specimens tested positive for Bartonella species for 56% of tested samples. A new genotype of Bartonella spp. was detected in 13/23 Eratyrus mucronatus specimens, an important vector of T. cruzi to humans. This bacterium was further characterized by sequencing fragments of the ftsZ, gltA and rpoB genes. Depending on the targeted gene, this agent shares 84% to 91% of identity with B. bacilliformis, the agent of Carrion's disease, a deadly sandfly-borne infectious disease endemic in South America. It is also closely related to animal pathogens such as B. bovis and B. chomelii. As E. mucronatus is an invasive species that occasionally feeds on humans, the presence of potentially pathogenic Bartonella-infected bugs could present another risk for human health, along with the T. cruzi issue.

  2. The biology of three Mexican-American species of Triatominae (Hemiptera: Reduviidae): Triatoma recurva, Triatoma protracta and Triatoma rubida.

    Science.gov (United States)

    Martínez-Ibarra, José Alejandro; Paredes-González, Edgar; Licón-Trillo, Ángel; Montañez-Valdez, Oziel Dante; Rocha-Chávez, Gonzalo; Nogueda-Torres, Benjamín

    2012-08-01

    The values of biological parameters related to hatching, lifespan, the number of blood meals between moults, mortality, time lapse before the beginning of feeding, feeding time and defecation delay for each instar of three Mexican-American species of Triatominae, Triatoma recurva, Triatoma protracta (former subspecies protracta) and Triatoma rubida (former subspecies uhleri), were evaluated and compared. No significant (p > 0.05) differences were recorded among the three species with respect to the average time required to hatch. This time was approximately 19 days. The average egg-to-adult development time was significantly (p < 0.05) shorter for T. rubida. The number of blood meals at each nymphal instar varied from one-five for each species. The mortality rates were higher for the first-instar nymphs of the three species studied. The mean time lapse before the beginning of feeding was between 0.3-3 min for most nymphs of all instars of each species studied. The mean feeding time was the longest for T. recurva, followed by T. protracta. The defecation delay was less than 10 min for T. recurva and T. rubida. Given these results, only T. rubida should be considered an important potential vector of Trypanosoma cruzi transmission to humans in areas of Mexico where these species exist, whereas T. recurva and T. protracta would be of secondary importance.

  3. The biology of three Mexican-American species of Triatominae (Hemiptera: Reduviidae: Triatoma recurva, Triatoma protracta and Triatoma rubida

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    José Alejandro Martínez-Ibarra

    2012-08-01

    Full Text Available The values of biological parameters related to hatching, lifespan, the number of blood meals between moults, mortality, time lapse before the beginning of feeding, feeding time and defecation delay for each instar of three Mexican-American species of Triatominae, Triatoma recurva, Triatoma protracta (former subspecies protracta and Triatoma rubida (former subspecies uhleri, were evaluated and compared. No significant (p > 0.05 differences were recorded among the three species with respect to the average time required to hatch. This time was approximately 19 days. The average egg-to-adult development time was significantly (p < 0.05 shorter for T. rubida. The number of blood meals at each nymphal instar varied from one-five for each species. The mortality rates were higher for the first-instar nymphs of the three species studied. The mean time lapse before the beginning of feeding was between 0.3-3 min for most nymphs of all instars of each species studied. The mean feeding time was the longest for T. recurva, followed by T. protracta. The defecation delay was less than 10 min for T. recurva and T. rubida. Given these results, only T. rubida should be considered an important potential vector of Trypanosoma cruzi transmission to humans in areas of Mexico where these species exist, whereas T. recurva and T. protracta would be of secondary importance.

  4. [Morphologic, morphometrical, and histological aspects of the eggs of four species of the genera Meccus (Hemiptera, Reduviidae, Triatominae)].

    Science.gov (United States)

    Obara, Marcos Takashi; Barata, José Maria Soares; da Silva, Nilza Nunes; Ceretti Júnior, Walter; Urbinatti, Paulo Roberto; da Rosa, João Aristeu; Jurberg, José; Galvão, Cleber

    2007-02-01

    The objective of this work was to analyze the morphological, morphometrical, and histological characteristics of eggs of four triatomine bugs species still not studied, in order to understand phylogenetic aspects and to facilitate parameters used in taxonomy, with the purpose of a specific and generic characterization of these vectors in public health. The eggs of each species had come from the collections of the Laboratory of Triatomine bugs and Culicid mosquitoes of the Faculdade de Saúde Pública - USP (Faculty of Public Health/USP). The morphologic studies were carried out through optic microscopy (OM) and scanning electronic microscopy (SEM). The eggs were measured with the help of the digital paquimeter Starrett 727. In relation to histological measures, Microtome Leica RM 2145 was used. Similarities were evidenced in the exocorial architecture of the eggs when they were studied by OM and SEM. This similarity among the eggs suggests a recent speciation, probably derived from common ancestry, representing a monophyletic group. Some structures were also detected by the histological cuts. The study has contributed to the magnification and recognition in generic and specific terms of the Triatominae subfamily. These new data will be able to subsidize a better understanding to determine roles for each vector species and to facilitate parameters to be used in taxonomy.

  5. [Development of Rhodnius pictipes Stal, 1872 fed on mice and through a silicone membrane (Hemiptera, Reduviidae, Triatominae)].

    Science.gov (United States)

    Rocha, D da S; da Fonseca, A H; Costa, F A; Jurberg, J; Galvão, C

    1997-01-01

    Rhodnius pictipes (Hemiptera, Reduviidae) from Serra Norte, State of Pará, Brazil, acclimatized in an insectary at the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Departamento de Entomologia, Instituto Oswaldo Cruz, were fed through a silicone membrane. In order to know the viability and the efficiency of this membrane compared with insects fed on mice, the number of bloodmeals taken, period of development of the five nymphal instars, longevity of adults, average amount of blood intake in each meal and percent of mortality were observed. A total of 310 insects, were used, comprising 50 nymphs of each instar, as well as 30 male and 30 female adults. Insects fed artificially had reduced minimal and maximal periods of development than the group fed on mice. The largest relative increase of body weight was observed in the 2nd instar followed by the 1st, and the amount of blood ingested increased during the development, to the 5th instar for both groups. There were no significant differences between the groups fed artificially and in vivo according to Tukey's test for p > 0.05. The percent of mortality in the 1st instar was 18% for artificially fed and 16% for the group fed on mice; these percentages decreased as insects developed until the 4th instar, without mortality, returning to increase in the 5th instar. R. pictipes was shown to be easily adaptable to artificial feeding, and could be considered as an important and viable experimental model.

  6. Detection of a Potential New Bartonella Species “Candidatus Bartonella rondoniensis” in Human Biting Kissing Bugs (Reduviidae; Triatominae)

    Science.gov (United States)

    Laroche, Maureen; Berenger, Jean-Michel; Mediannikov, Oleg; Raoult, Didier; Parola, Philippe

    2017-01-01

    Background Among the Reduviidae family, triatomines are giant blood-sucking bugs. They are well known in Central and South America where they transmit Trypanosoma cruzi to mammals, including humans, through their feces. This parasitic protozoan is the causative agent of Chagas disease, a major public health issue in endemic areas. Because of the medical and economic impact of Chagas disease, the presence of other arthropod-borne pathogens in triatomines was rarely investigated. Methodology/Principal findings In this study, seven triatomines species involved in the transmission of T. cruzi were molecularly screened for the presence of known pathogens generally associated with arthropods, such as Rickettsia, Bartonella, Anaplasmataceae, Borrelia species and Coxiella burnetii. Of all included triatomine species, only Eratyrus mucronatus specimens tested positive for Bartonella species for 56% of tested samples. A new genotype of Bartonella spp. was detected in 13/23 Eratyrus mucronatus specimens, an important vector of T. cruzi to humans. This bacterium was further characterized by sequencing fragments of the ftsZ, gltA and rpoB genes. Depending on the targeted gene, this agent shares 84% to 91% of identity with B. bacilliformis, the agent of Carrion’s disease, a deadly sandfly-borne infectious disease endemic in South America. It is also closely related to animal pathogens such as B. bovis and B. chomelii. Conclusions As E. mucronatus is an invasive species that occasionally feeds on humans, the presence of potentially pathogenic Bartonella-infected bugs could present another risk for human health, along with the T. cruzi issue. PMID:28095503

  7. Detection of a Potential New Bartonella Species "Candidatus Bartonella rondoniensis" in Human Biting Kissing Bugs (Reduviidae; Triatominae.

    Directory of Open Access Journals (Sweden)

    Maureen Laroche

    2017-01-01

    Full Text Available Among the Reduviidae family, triatomines are giant blood-sucking bugs. They are well known in Central and South America where they transmit Trypanosoma cruzi to mammals, including humans, through their feces. This parasitic protozoan is the causative agent of Chagas disease, a major public health issue in endemic areas. Because of the medical and economic impact of Chagas disease, the presence of other arthropod-borne pathogens in triatomines was rarely investigated.In this study, seven triatomines species involved in the transmission of T. cruzi were molecularly screened for the presence of known pathogens generally associated with arthropods, such as Rickettsia, Bartonella, Anaplasmataceae, Borrelia species and Coxiella burnetii. Of all included triatomine species, only Eratyrus mucronatus specimens tested positive for Bartonella species for 56% of tested samples. A new genotype of Bartonella spp. was detected in 13/23 Eratyrus mucronatus specimens, an important vector of T. cruzi to humans. This bacterium was further characterized by sequencing fragments of the ftsZ, gltA and rpoB genes. Depending on the targeted gene, this agent shares 84% to 91% of identity with B. bacilliformis, the agent of Carrion's disease, a deadly sandfly-borne infectious disease endemic in South America. It is also closely related to animal pathogens such as B. bovis and B. chomelii.As E. mucronatus is an invasive species that occasionally feeds on humans, the presence of potentially pathogenic Bartonella-infected bugs could present another risk for human health, along with the T. cruzi issue.

  8. Morfometría geométrica del borde corial y del collar de huevos de cinco especies del género Rhodnius Stal (Heteroptera, Reduviidae, Triatominae

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    Ximena Páez-Colasante

    2008-12-01

    Full Text Available Resumen. La taxonomía y sistemática de la subfamilia Triatominae (Heteroptera, Reduviidae se basan principalmente en caracteres biométricos y morfológicos de las formas adultas y, en algunos casos, de las ninfas. La Morfometría Geométrica es capaz de descomponer la forma en sus componentes tamaño isométrico y conformación. En el presente trabajo se utilizó laMorfometría Geométrica como herramienta de análisis de la configuración geométrica que resulta de la unión de los extremos del borde corial y del collar (configuración borde corial-collar de los huevos eclosionados de cinco especies del género Rhodnius Stal. Los huevos se observaron por Microscopía Electrónica de Barrido y las imágenes digitalizadas fueron analizadas morfogeométricamente. Estudiando el tamaño geométrico de la configuración borde corial-collar, se halló que no existen diferencias estadísticamente significativas entre las cinco especies deTriatominos. En cuanto a la conformación, se determinaron diferencias entre las especies al ser sometidas a un análisis discriminante. Se encontró además que la variación del tamaño contribuye a la variación en la conformación, es decir, efecto alométrico. Los resultados obtenidos indican que la conformación de la configuración geométrica “borde corial-collar” de los huevos de Rhodnius podría ser utilizada como herramienta taxonómica para este grupo. Morfometria geométrica da borda corial e colarinho de ovos de cinco espécies do Gênero Rhodnius (Heteroptera Reduviidae, Triatominae.Resumo. A taxonomia e sistemática da subfamília Triatominae (Heteroptera Reduviidae esta baseada principalmente em caracteres biométricos e morfológicos das formas adultas, e em alguns casos, das ninfas. A morfometria geométrica é capaz de descompor a forma em seus componentes, tamanho isométrico e conformação. No presente trabalho utilizou-se a morfometria geométrica como ferramenta de análise da configura

  9. Susceptibilidade de Rhodnius neglectus, Rhodnius robustus e Triatoma infestans (Hemiptera, Reduviidae, Triatominae à infecção por duas cepas de Trypanosoma cruzi (Kinetoplastidae, Trypanosomatidae utilizando xenodiagnóstico artificial Susceptibility of Rhodnius neglectus, Rhodnius robustus and Triatoma infestans (Hemiptera, Reduviidae, Triatominae to two Trypanosoma cruzi strains infection (Kinetoplastidae, Trypanosomatidae using artificial xenodiagnosis

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    Luciamáre Perinetti Alves Martins

    2000-12-01

    Full Text Available A susceptibilidade de ninfas de 3º estádio de Rhodnius neglectus, R. robustus e Triatoma infestans às cepas Y e AMJM de Trypanosoma cruzi foi verificada utilizando xenodiagnóstico artificial. Para a leitura do xenodiagnóstico, as fezes dos triatomíneos foram examinadas a cada dois dias, a partir do 5º até o 31º dia pós infecção, pela técnica de compressão abdominal. Os resultados mostraram diferenças na susceptibilidade dos triatomíneos para as duas cepas estudadas e o período ótimo de leitura variou do 11º ao 19º dias para a cepa Y e do 11º ao 15º dias para a cepa AMJM. Também, pôde-se concluir que para a cepa Y, as três espécies de triatomíneos demonstraram boa susceptibilidade, enquanto para a cepa AMJM, a melhor susceptibilidade foi observada com R. neglectus, seguida pelo T. infestans e R. robustus.The susceptibility of 3rd instar nymph of Triatominae Rhodnius neglectus, R. robustus and Triatoma infestans to Trypanosoma cruzi Y and AMJM strains was verified using artificial xenodiagnosis. After the accomplishment of the xenodiagnosis, the faeces of the Triatominae were analyzed on two-day intervals from day 5 until day 31 post infection, using the abdominal compression technique. The results showed differences in the susceptibility of the Triatominae for the two strains studied, and the optimal period reading differed from day 11 to day 19 for the Y strain and from day 11 to day 15 for the AMJM strain. For the Y strain, all three Triatominae species showed good susceptibility, whereas in the AMJM strain, the highest susceptibility was observed with R. neglectus, followed by T. infestans and R. robustus.

  10. Toxicological, Enzymatic, and Molecular Assessment of the Insecticide Susceptibility Profile of Triatoma infestans (Hemiptera: Reduviidae, Triatominae) Populations From Rural Communities of Santa Cruz, Bolivia.

    Science.gov (United States)

    Santo-Orihuela, Pablo L; Vassena, Claudia V; Carvajal, Guillermo; Clark, Eva; Menacho, Silvio; Bozo, Ricardo; Gilman, Robert H; Bern, Caryn; Marcet, Paula L

    2017-01-01

    A wide range of insecticide resistance profiles has been reported across Bolivian domestic and sylvatic populations of Triatoma infestans (Klug, 1834) (Hemiptera, Reduviidae), including some with levels proven to be a threat for vector control. In this work, the insecticide profile of domestic T. infestans was studied with standardized toxicological bioassays, in an area that has not undergone consistent vector control. F1 first-instar nymphs hatched in laboratory from bugs captured in three communities from the Santa Cruz Department were evaluated with different insecticides. Moreover, the enzymatic activity of esterases and cytochrome P450 monooxygenases was measured in individual insects to evaluate the possible mechanism of metabolic resistance to pyrethroids. In addition, the DNA sequence of sodium channel gene (kdr) was screened for two point mutations associated with pyrethroid resistance previously reported in T. infestans.All populations showed reduced susceptibility to deltamethrin and α-cypermethrin, albeit the RR50 values varied significantly among them. Increased P450 monooxygenases and permethrate esterases suggest the contribution, as detoxifying mechanisms, to the observed resistance to deltamethrin in all studied populations. No individuals presented either mutation associated to resistance in the kdr gene. The level of susceptibility to α-cypermethrin, the insecticide used by the local vector control program, falls within an acceptable range to continue its use in these populations. However, the observed RR50 values evidence the possibility of selection for resistance to pyrethroids, especially to deltamethrin. Consequently, the use of pyrethroid insecticides should be closely monitored in these communities, which should be kept under entomological surveillance and sustained interventions. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email

  11. The Heteroptera of the Netherlands Antilles – IX Reduviidae (Assassin Bugs)

    NARCIS (Netherlands)

    Cobben, R.H.; Wygodzinsky, P.

    1975-01-01

    A survey is given of the assassin bugs (Reduviidae) collected on the six Netherlands Antilles. All together 22 species were sampled: 6 Emesinae, 1 Saicinae, 8 Harpactorinae, 1 Piratinae, 4 Stenopodinae, 1 Triatominae and 1 Phymatinae. Sixteen species were captured on the three islands of the Leeward

  12. Insects found in birds' nests from Argentina: Coryphistera alaudina Burmeister, 1860 (Aves: Furnariidae), their inquiline birds and mammals, new hosts for Psammolestes coreodes Bergroth, 1911 and Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    Turienzo, Paola; Di Iorio, Osvaldo

    2014-06-03

    The insect fauna in nests of Coryphistera alaudina Burmeister, 1860 (Aves: Furnariidae) were studied in the provinces of Santiago del Estero, Chaco, Córdoba, and La Pampa in Argentina. A total of 7364 insect specimens comprising 77 taxa in a total of 29 families and 7 orders was found in their nests: 40 identified to species, 23 identified to genus, and 14 identified to family. Coryphistera alaudina and some of their vertebrate inquilines are new host records for the triatomine bugs Psammolestes coreodes Bergroth, 1911 and/or Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae). The insects in the nests of C. alaudina are separated by functional guilds, and their permanence time inside the nests are presented in a new manner and discussed.

  13. Phylogenetic approach to the study of Triatomines (Triatominae, Heteroptera).

    Science.gov (United States)

    Tartarotti, E; Azeredo-Oliveira, M T V; Ceron, C R

    2006-05-01

    Triatomines are insects belonging to the Hemiptera order, Heteroptera suborder, Reduviidae family and Triatominae subfamily. All members of this subfamily are hematophagous. Triatomines evolved from Reduviidae predators and they are probably polyphyletic in origin. The combination of anatomical, physiological and ethological factors observed in this group, as well as the plesiomorphic and apomorphic characters that differentiate the five tribes and fourteen triatomine genera reinforce the polyphiletic hypotesis. However if we consider the five groups of triatomines, the Rhodniini, Cavernicolini, Bolboderini, Linshcosteini and Alberproseniini tribes constitute monophyletic groups, while the Triatomini tribe is considered polyphyletic. The New World is the center of triatomine diversity and seems to be the point of group origin. Of approximately 137 triatomine species, 105 are only found in the Americas. It is now considered that triatomines represent a polyphyletic group defined according to their convergent apomorphic hematophagous characters, which have appeared several times in Reduviidae. This study revises the phylogeny of these vectors of Chagas' disease, covering such topics as the origin of hematophagy in triatomines and ancestral proposal for the group.

  14. Phylogenetic approach to the study of Triatomines (Triatominae, Heteroptera

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    E. Tartarotti

    Full Text Available Triatomines are insects belonging to the Hemiptera order, Heteroptera suborder, Reduviidae family and Triatominae subfamily. All members of this subfamily are hematophagous. Triatomines evolved from Reduviidae predators and they are probably polyphyletic in origin. The combination of anatomical, physiological and ethological factors observed in this group, as well as the plesiomorphic and apomorphic characters that differentiate the five tribes and fourteen triatomine genera reinforce the polyphiletic hypotesis. However if we consider the five groups of triatomines, the Rhodniini, Cavernicolini, Bolboderini, Linshcosteini and Alberproseniini tribes constitute monophyletic groups, while the Triatomini tribe is considered polyphyletic. The New World is the center of triatomine diversity and seems to be the point of group origin. Of approximately 137 triatomine species, 105 are only found in the Americas. It is now considered that triatomines represent a polyphyletic group defined according to their convergent apomorphic hematophagous characters, which have appeared several times in Reduviidae. This study revises the phylogeny of these vectors of Chagas' disease, covering such topics as the origin of hematophagy in triatomines and ancestral proposal for the group.

  15. Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard and Borellia bruneri (Rehn (Orthoptera: Acrididae

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    Yanina Mariottini

    2015-06-01

    Full Text Available Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005-06 to 2011-12 in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p > 0.05, suggesting that these species have such a primary sex ratio. However, a significant bias in sex composition in adults of both species was observed (p < 0.05. The sex ratio in adults of D. maculipennis was different in five of the 18 sampling dates carried out. In three sampling dates it was biased toward males, while in the other two it was biased toward females. Taking into account the sex ratio by sampling season, significant differences were recorded in two seasons. In 2007-08 the sex ratio was biased toward males (1 F:2.26 M, while in 2008-09 it was biased toward females (1.35 F:1 M. The sex ratio in adults of B. bruneri was always biased toward males (p < 0.05. We conclude that results obtained in this study indicate that various factors like differential survival, dispersion, predation, among others, could have modified the primary sex ratio in these species.

  16. Evolutionary History of Assassin Bugs (Insecta: Hemiptera: Reduviidae): Insights from Divergence Dating and Ancestral State Reconstruction

    Science.gov (United States)

    Hwang, Wei Song; Weirauch, Christiane

    2012-01-01

    Assassin bugs are one of the most successful clades of predatory animals based on their species numbers (∼6,800 spp.) and wide distribution in terrestrial ecosystems. Various novel prey capture strategies and remarkable prey specializations contribute to their appeal as a model to study evolutionary pathways involved in predation. Here, we reconstruct the most comprehensive reduviid phylogeny (178 taxa, 18 subfamilies) to date based on molecular data (5 markers). This phylogeny tests current hypotheses on reduviid relationships emphasizing the polyphyletic Reduviinae and the blood-feeding, disease-vectoring Triatominae, and allows us, for the first time in assassin bugs, to reconstruct ancestral states of prey associations and microhabitats. Using a fossil-calibrated molecular tree, we estimated divergence times for key events in the evolutionary history of Reduviidae. Our results indicate that the polyphyletic Reduviinae fall into 11–14 separate clades. Triatominae are paraphyletic with respect to the reduviine genus Opisthacidius in the maximum likelihood analyses; this result is in contrast to prior hypotheses that found Triatominae to be monophyletic or polyphyletic and may be due to the more comprehensive taxon and character sampling in this study. The evolution of blood-feeding may thus have occurred once or twice independently among predatory assassin bugs. All prey specialists evolved from generalist ancestors, with multiple evolutionary origins of termite and ant specializations. A bark-associated life style on tree trunks is ancestral for most of the lineages of Higher Reduviidae; living on foliage has evolved at least six times independently. Reduviidae originated in the Middle Jurassic (178 Ma), but significant lineage diversification only began in the Late Cretaceous (97 Ma). The integration of molecular phylogenetics with fossil and life history data as presented in this paper provides insights into the evolutionary history of reduviids and clears

  17. Evolution, Systematics, and Biogeography of the Triatominae, Vectors of Chagas Disease.

    Science.gov (United States)

    Monteiro, Fernando Araujo; Weirauch, Christiane; Felix, Márcio; Lazoski, Cristiano; Abad-Franch, Fernando

    2018-01-01

    In this chapter, we review and update current knowledge about the evolution, systematics, and biogeography of the Triatominae (Hemiptera: Reduviidae)-true bugs that feed primarily on vertebrate blood. In the Americas, triatomines are the vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Despite declining incidence and prevalence, Chagas disease is still a major public health concern in Latin America. Triatomines occur also in the Old World, where vector-borne T. cruzi transmission has not been recorded. Triatomines evolved from predatory reduviid bugs, most likely in the New World, and diversified extensively across the Americas (including the Caribbean) and in parts of Asia and Oceania. Here, we first discuss our current understanding of how, how many times, and when the blood-feeding habit might have evolved among the Reduviidae. Then we present a summary of recent advances in the systematics of this diverse group of insects, with an emphasis on the contribution of molecular tools to the clarification of taxonomic controversies. Finally, and in the light of both up-to-date phylogenetic hypotheses and a thorough review of distribution records, we propose a global synthesis of the biogeography of the Triatominae. Over 130 triatomine species contribute to maintaining T. cruzi transmission among mammals (sometimes including humans) in almost every terrestrial ecoregion of the Americas. This means that Chagas disease will never be eradicated and underscores the fact that effective disease prevention will perforce require stronger, long-term vector control-surveillance systems. © 2018 Elsevier Ltd All rights reserved.

  18. The triatominae species of French Guiana (Heteroptera: Reduviidae).

    Science.gov (United States)

    Bérenger, Jean-Michel; Pluot-Sigwalt, Dominique; Pagès, Frédéric; Blanchet, Denis; Aznar, Christine

    2009-12-01

    An annotated list of the triatomine species present in French Guiana is given. It is based on field collections carried out between 1993-2008, museum collections and a literature review. Fourteen species, representing four tribes and six genera, are now known in this country and are illustrated (habitus). Three species are recorded from French Guiana for the first time: Cavernicola pilosa, Microtriatoma trinidadensis and Rhodnius paraensis. The two most common and widely distributed species are Panstrongylus geniculatus and Rhodnius pictipes. The presence of two species (Panstrongylus megistus and Triatoma maculata) could be fortuitous and requires confirmation. Also, the presence of Rhodnius prolixus is doubtful; while it was previously recorded in French Guiana, it was probably mistaken for R. robustus. A key for French Guiana's triatomine species is provided.

  19. A new species of Rhodnius from Brazil (Hemiptera, Reduviidae, Triatominae)

    Science.gov (United States)

    da Rosa, João Aristeu; Justino, Hernany Henrique Garcia; Nascimento, Juliana Damieli; Mendonça, Vagner José; Rocha, Claudia Solano; de Carvalho, Danila Blanco; Falcone, Rossana; Oliveira, Maria Tercília Vilela de Azeredo; Alevi, Kaio Cesar Chaboli; de Oliveira, Jader

    2017-01-01

    Abstract A colony was formed from eggs of a Rhodnius sp. female collected in Taquarussu, Mato Grosso do Sul, Brazil, and its specimens were used to describe R. taquarussuensis sp. n. This species is similar to R. neglectus, but distinct characters were observed on the head, thorax, abdomen, female external genitalia and male genitalia. Chromosomal differences between the two species were also established. PMID:28769676

  20. Trapping Triatominae in Silvatic Habitats

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    Noireau François

    2002-01-01

    Full Text Available Large-scale trials of a trapping system designed to collect silvatic Triatominae are reported. Live-baited adhesive traps were tested in various ecosystems and different triatomine habitats (arboreal and terrestrial. The trials were always successful, with a rate of positive habitats generally over 20% and reaching 48.4% for palm trees of the Amazon basin. Eleven species of Triatominae belonging to the three genera of public health importance (Triatoma, Rhodnius and Panstrongylus were captured. This trapping system provides an effective way to detect the presence of triatomines in terrestrial and arboreal silvatic habitats and represents a promising tool for ecological studies. Various lines of research are contemplated to improve the performance of this trapping system.

  1. [Triatominae: growing trend to domesticity].

    Science.gov (United States)

    Berenger, J M; Pages, F

    2007-06-01

    Triatominae are biting hematophageous insects that have been wild vectors of the parasite Trypanosoma curzi for thousands of years. The arrival of man with his cortege of domestic animals and impact on the natural environment led these insects to adapt to the human environment so well that many species are now domesticated. Insect extermination programs have allowed satisfactory control of parasite transmission but have also promoted replacement of the exterminated species by species that were once semi-domestic or wild.

  2. Ecotope effect in Triatoma brasiliensis (Hemiptera: Reduviidae) suggests phenotypic plasticity rather than adaptation.

    Science.gov (United States)

    Batista, V S P; Fernandes, F A; Cordeiro-Estrela, P; Sarquis, O; Lima, M M

    2013-09-01

    Triatoma brasiliensis (Hemiptera: Reduviidae) is an important vector of Chagas' disease in both sylvatic and peridomestic ecotopes. Discriminating between these populations of Triatominae has been proposed as a means of investigating re-infestation rates of human dwellings. Geometric morphometrics have been widely applied in the study of Triatominae polymorphisms at species and population levels. This study characterizes morphometric differences between sylvatic and peridomestic populations, as well as between sexes in T. brasiliensis specimens from Jaguaruana, Ceará, in northeastern Brazil. No differences in either the shape or size of the cephalic capsule were apparent between sexes or ecotopes. However, the wings showed differentiation in shape and size. Sexual dimorphism was detected, with females presenting significantly higher values and conformations. Size differentiation was also evident, with sylvatic specimens being generally larger than peridomestic examples. These results indicate that differences in the wings of T. brasiliensis may be related to the existence of phenotypic plasticity, and variations in size and shape may be associated with different ecotopes, possibly as a result of conditions in each micro-habitat, such as temperature, relative humidity, food supply and density. © 2012 The Royal Entomological Society.

  3. Heterochromatin base pair composition and diversification in holocentric chromosomes of kissing bugs (Hemiptera, Reduviidae)

    Science.gov (United States)

    Bardella, Vanessa Bellini; Pita, Sebastián; Vanzela, André Luis Laforga; Galvão, Cleber; Panzera, Francisco

    2016-01-01

    The subfamily Triatominae (Hemiptera, Reduviidae) includes 150 species of blood-sucking insects, vectors of Chagas disease or American trypanosomiasis. Karyotypic information reveals a striking stability in the number of autosomes. However, this group shows substantial variability in genome size, the amount and distribution of C-heterochromatin, and the chromosome positions of 45S rDNA clusters. Here, we analysed the karyotypes of 41 species from six different genera with C-fluorescence banding in order to evaluate the base-pair richness of heterochromatic regions. Our results show a high heterogeneity in the fluorescent staining of the heterochromatin in both autosomes and sex chromosomes, never reported before within an insect subfamily with holocentric chromosomes. This technique allows a clear discrimination of the heterochromatic regions classified as similar by C-banding, constituting a new chromosome marker with taxonomic and evolutionary significance. The diverse fluorescent patterns are likely due to the amplification of different repeated sequences, reflecting an unusual dynamic rearrangement in the genomes of this subfamily. Further, we discuss the evolution of these repeated sequences in both autosomes and sex chromosomes in species of Triatominae. PMID:27759763

  4. Heterochromatin base pair composition and diversification in holocentric chromosomes of kissing bugs (Hemiptera, Reduviidae

    Directory of Open Access Journals (Sweden)

    Vanessa Bellini Bardella

    Full Text Available The subfamily Triatominae (Hemiptera, Reduviidae includes 150 species of blood-sucking insects, vectors of Chagas disease or American trypanosomiasis. Karyotypic information reveals a striking stability in the number of autosomes. However, this group shows substantial variability in genome size, the amount and distribution of C-heterochromatin, and the chromosome positions of 45S rDNA clusters. Here, we analysed the karyotypes of 41 species from six different genera with C-fluorescence banding in order to evaluate the base-pair richness of heterochromatic regions. Our results show a high heterogeneity in the fluorescent staining of the heterochromatin in both autosomes and sex chromosomes, never reported before within an insect subfamily with holocentric chromosomes. This technique allows a clear discrimination of the heterochromatic regions classified as similar by C-banding, constituting a new chromosome marker with taxonomic and evolutionary significance. The diverse fluorescent patterns are likely due to the amplification of different repeated sequences, reflecting an unusual dynamic rearrangement in the genomes of this subfamily. Further, we discuss the evolution of these repeated sequences in both autosomes and sex chromosomes in species of Triatominae.

  5. Deciphering morphology in Triatominae: the evolutionary signals.

    Science.gov (United States)

    Dujardin, J P; Costa, J; Bustamante, D; Jaramillo, N; Catalá, S

    2009-01-01

    Many species of Triatominae show evidence for morphological plasticity. Frequent taxonomic questions arose from this variability leading to disputes about describing new subspecies, species or even genera. We suggest this phenotypic flexibility is primarily an intraspecific feature, but with potential for evolutionary changes. We present arguments for a selection regime leading to the separation of species having low developmental canalization into morphologically distinct ecotypes. We suggest that these ecotypes, or morphs, or forms, may have evolutionary importance even if gene flow still exists between them. Thus, although we consider the morphological plasticity of Triatominae as an intraspecific trait, we defend the idea that it might represent a common evolutionary route to new species. Speciation processes in Triatominae could result from disruptive selection regimes combined with weak developmental canalization. Added to this basic pattern, accidental events could hasten evolutionary change. We suggest the heterosis as one of them.

  6. Study of the Salivary Glands in Triatominae (Hemiptera, Reduviidae, Triatominae): Their Color and Application to the Chagas Disease Vector Evolution.

    Science.gov (United States)

    de Oliveira, Jader; Ravazi, Amanda; Souza, Eder Dos Santos; Moreira, Felipe Ferraz Figueiredo; Galvão, Cleber; da Rosa, João Aristeu; Alevi, Kaio Cesar Chaboli

    2017-09-01

    Chagas disease is caused by Trypanosoma cruzi and transmitted by feces of a triatomine that has the habit of defecating during blood feeding. The salivary glands of triatomines are important to hematophagy because their saliva is rich in anticoagulant and hemolytic proteins. The salivary glands of some Rhodnius species analyzed are reddish due to the presence of nitrophorins (antihemostatic activity). The present study aimed to analyze the color pattern of the salivary glands of 67 triatomine species to evaluate whether the presence of nitrophorins is a synapomorphy of Rhodnius or the tribe Rhodniini, or if it is shared with triatomines of the tribes Triatomini and Cavernicolini. Since only the species of the tribe Rhoniini present red glands, it is admitted that the presence of nitrophorin proteins is a synapomorphy of the tribe Rhodniini and that this tribe has derived more recently when compared with Triatomini and Cavernicolini.

  7. The presence of the ancestral insect telomeric motif in kissing bugs (Triatominae) rules out the hypothesis of its loss in evolutionarily advanced Heteroptera (Cimicomorpha)

    Science.gov (United States)

    Pita, Sebastián; Panzera, Francisco; Mora, Pablo; Vela, Jesús; Palomeque, Teresa; Lorite, Pedro

    2016-01-01

    Abstract Next-generation sequencing data analysis on Triatoma infestans Klug, 1834 (Heteroptera, Cimicomorpha, Reduviidae) revealed the presence of the ancestral insect (TTAGG)n telomeric motif in its genome. Fluorescence in situ hybridization confirms that chromosomes bear this telomeric sequence in their chromosomal ends. Furthermore, motif amount estimation was about 0.03% of the total genome, so that the average telomere length in each chromosomal end is almost 18 kb long. We also detected the presence of (TTAGG)n telomeric repeat in mitotic and meiotic chromosomes in other three species of Triatominae: Triatoma dimidiata Latreille, 1811, Dipetalogaster maxima Uhler, 1894, and Rhodnius prolixus Ståhl, 1859. This is the first report of the (TTAGG)n telomeric repeat in the infraorder Cimicomorpha, contradicting the currently accepted hypothesis that evolutionarily recent heteropterans lack this ancestral insect telomeric sequence. PMID:27830050

  8. Melt With This Kiss: Paralyzing and Liquefying Venom of The Assassin Bug Pristhesancus plagipennis (Hemiptera: Reduviidae).

    Science.gov (United States)

    Walker, Andrew A; Madio, Bruno; Jin, Jiayi; Undheim, Eivind A B; Fry, Bryan G; King, Glenn F

    2017-04-01

    Assassin bugs (Hemiptera: Heteroptera: Reduviidae) are venomous insects, most of which prey on invertebrates. Assassin bug venom has features in common with venoms from other animals, such as paralyzing and lethal activity when injected, and a molecular composition that includes disulfide-rich peptide neurotoxins. Uniquely, this venom also has strong liquefying activity that has been hypothesized to facilitate feeding through the narrow channel of the proboscis-a structure inherited from sap- and phloem-feeding phytophagous hemipterans and adapted during the evolution of Heteroptera into a fang and feeding structure. However, further understanding of the function of assassin bug venom is impeded by the lack of proteomic studies detailing its molecular composition.By using a combined transcriptomic/proteomic approach, we show that the venom proteome of the harpactorine assassin bug Pristhesancus plagipennis includes a complex suite of >100 proteins comprising disulfide-rich peptides, CUB domain proteins, cystatins, putative cytolytic toxins, triabin-like protein, odorant-binding protein, S1 proteases, catabolic enzymes, putative nutrient-binding proteins, plus eight families of proteins without homology to characterized proteins. S1 proteases, CUB domain proteins, putative cytolytic toxins, and other novel proteins in the 10-16-kDa mass range, were the most abundant venom components. Thus, in addition to putative neurotoxins, assassin bug venom includes a high proportion of enzymatic and cytolytic venom components likely to be well suited to tissue liquefaction. Our results also provide insight into the trophic switch to blood-feeding by the kissing bugs (Reduviidae: Triatominae). Although some protein families such as triabins occur in the venoms of both predaceous and blood-feeding reduviids, the composition of venoms produced by these two groups is revealed to differ markedly. These results provide insights into the venom evolution in the insect suborder

  9. History of insecticide resistance of Triatominae vectors.

    Science.gov (United States)

    Pessoa, Grasielle Caldas Dávila; Vinãs, Pedro Albajar; Rosa, Aline Cristine Luiz; Diotaiuti, Liléia

    2015-01-01

    In the last 15 years, different types of Triatominae resistance to different insecticides have been reported; thus, resistance may be more widespread than known, requiring better characterization and delimitation, which was the aim of this review. This review was structured on a literature search of all articles from 1970 to 2015 in the PubMed database that contained the keywords Insecticide resistance and Triatominae . Out of 295 articles screened by title, 33 texts were selected for detailed analysis. Insecticide resistance of Triatomines is a complex phenomenon that has been primarily reported in Argentina and Bolivia, and is caused by different factors (associated or isolated). Insecticide resistance of Triatominae is a characteristic inherited in an autosomal and semi-dominant manner, and is polygenic, being present in both domestic and sylvatic populations. The toxicological profile observed in eggs cannot be transposed to different stages of evolution. Different toxicological profiles exist at macro- and microgeographical levels. The insecticide phenotype has both reproductive and developmental costs. Different physiological mechanisms are involved in resistance. Studies of Triatomine resistance to insecticides highlight three deficiencies in interpreting the obtained results: I) the vast diversity of methodologies, despite the existence of a single guiding protocol; II) the lack of information on the actual impact of resistance ratios in the field; and III) the concept of the susceptibility reference lineage. Research on the biological and behavioral characteristics of each Triatominae species that has evolved resistance is required in relation to the environmental conditions of each region.

  10. Cryptic speciation in the Triatoma sordida subcomplex (Hemiptera, Reduviidae) revealed by chromosomal markers.

    Science.gov (United States)

    Panzera, Francisco; Pita, Sebastián; Nattero, Julieta; Panzera, Yanina; Galvão, Cleber; Chavez, Tamara; Rojas De Arias, Antonieta; Cardozo Téllez, Lourdes; Noireau, François

    2015-09-29

    Chagas disease vectors (Hemiptera-Reduviidae) comprise more than 140 blood-sucking insect species of the Triatominae subfamily. The largest genus is Triatoma, subdivided in several complexes and subcomplexes according to morphology, ecology and genetic features. One of them is the sordida subcomplex, involving four species: Triatoma sordida, T. guasayana, T. garciabesi and T. patagonica. Given the great morphological similarity of these species, their taxonomic identification, evolutionary relationships and population differentiation have been controversial for many years and even today remain under discussion. We simultaneously analyzed two chromosomal markers, C-heterochromatin distribution and 45S ribosomal genes chromosomal position, of 139 specimens from several sordida subcomplex populations from Argentina, Bolivia, Brazil and Paraguay, collected both in nature and from several established insectaries. Our results were compared with COI sequences deposited in GenBank. We recognized five chromosomal taxa with putative hybrids, which each differ in at least one chromosome marker. Most of them present significant differences in their mtDNA sequences. The chromosomal taxa here show a significant chromosome differentiation involving changes in the C-heterochromatin content and in the ribosomal clusters position. This paper identifies several erroneously classified populations by morphological methods, delimits the geographical distribution of each taxon and proposes the existence of a new cryptic species, widely distributed in Argentina. We also suggest that sordida sibling species involve closely related as well as evolutionary distant species. Taxonomic status of each chromosomal taxon is discussed considering phenotypic and genetic results previously published.

  11. The cuticular hydrocarbons of the Triatoma sordida species subcomplex (Hemiptera: Reduviidae).

    Science.gov (United States)

    Calderón-Fernández, Gustavo Mario; Juárez, Marta Patricia

    2013-09-01

    The cuticular hydrocarbons of the Triatoma sordida subcomplex (Hemiptera: Reduviidae: Triatominae) were ana-lysed by gas chromatography and their structures identified by mass spectrometry. They comprised mostly n-alkanes and methyl-branched alkanes with one-four methyl substitutions. n-alkanes consisted of a homologous series from C21-C33 and represented 33-45% of the hydrocarbon fraction; n-C29 was the major component. Methyl-branched alkanes showed alkyl chains from C24-C43. High molecular weight dimethyl and trimethylalkanes (from C35-C39) represented most of the methyl-branched fraction. A few tetramethylalkanes were also detected, comprising mostly even-numbered chains. Several components such as odd-numbered 3-methylalkanes, dimethylalkanes and trimethylalkanes of C37 and C39 showed patterns of variation that allowed the differentiation of the species and populations studied. Triatoma guasayana and Triatoma patagonica showed the most distinct hydrocarbon patterns within the subcomplex. The T. sordida populations from Brazil and Argentina showed significantly different hydrocarbon profiles that posed concerns regarding the homogeneity of the species. Triatoma garciabesi had a more complex hydrocarbon pattern, but it shared some similarity with T. sordida. The quantitative and qualitative variations in the cuticular hydrocarbons may help to elucidate the relationships between species and populations of this insect group.

  12. The cuticular hydrocarbons of the Triatoma sordida species subcomplex (Hemiptera: Reduviidae

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    Gustavo Mario Calderon-Fernandez

    2013-09-01

    Full Text Available The cuticular hydrocarbons of the Triatoma sordida subcomplex (Hemiptera: Reduviidae: Triatominae were ana-lysed by gas chromatography and their structures identified by mass spectrometry. They comprised mostly n-alkanes and methyl-branched alkanes with one-four methyl substitutions. n-alkanes consisted of a homologous series from C21-C33 and represented 33-45% of the hydrocarbon fraction; n-C29 was the major component. Methyl-branched alkanes showed alkyl chains from C24-C43. High molecular weight dimethyl and trimethylalkanes (from C35-C39 represented most of the methyl-branched fraction. A few tetramethylalkanes were also detected, comprising mostly even-numbered chains. Several components such as odd-numbered 3-methylalkanes, dimethylalkanes and trimethylalkanes of C37 and C39 showed patterns of variation that allowed the differentiation of the species and populations studied. Triatoma guasayana and Triatoma patagonica showed the most distinct hydrocarbon patterns within the subcomplex. The T. sordida populations from Brazil and Argentina showed significantly different hydrocarbon profiles that posed concerns regarding the homogeneity of the species. Triatoma garciabesi had a more complex hydrocarbon pattern, but it shared some similarity with T. sordida. The quantitative and qualitative variations in the cuticular hydrocarbons may help to elucidate the relationships between species and populations of this insect group.

  13. Some considerations about the ecology of Triatominae

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    François Noireau

    2005-09-01

    Full Text Available Observations on the ecology of silvatic Triatominae are still fragmentary, principally because target species in control process are almost exclusively domestic. Report of silvatic species invading human dwellings must lead research to be focused on their original ecology, in order to assist in understanding their process of domestication and devising strategies for surveillance.As informações sobre a ecologia de Triatominae silvestres são ainda incompletas, sobretudo porque as espécies mais importantes, alvos dos programas de controle, são exclusivamente domésticas. Registros de espécies silvestres invadindo as habitações humanas devem ser investigados para ampliação do conhecimento de sua ecologia no ambiente natural, de modo que se possa compreender melhor o processo de domiciliação e se criar novas estratégias para vigilância.

  14. Karyotype of Rhodnius montenegrensis (Hemiptera, Triatominae).

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    Alevi, K C C; Ravazi, A; Mendonça, V J; Rosa, J A; Azeredo-Oliveira, M T V

    2015-01-16

    The Triatominae subfamily comprises 6 tribes. The tribe Rhodniini comprises 2 genera and 22 nominal species. Rhodnius montenegrensis (Hemiptera, Triatominae) was recently described as evolutionarily related to R. robustus. Therefore, in order to contribute to karyosystematic study of the tribe Rhodniini, this report describes the number of chromosomes and compares the karyotype of R. montenegrensis to that of all other species in the tribe, in order to determine the karyotypic evolution of the tribe Rhodniini. The seminiferous tubules of adult males, after being removed and fixated on a cover slip, were processed with lacto-aceto-orcein for cytogenetic analysis. R. montenegrensis, as well as all other species of the tribe Rhodniini showed 22 chromosomes (20 autosomes + XY). Thus, we hereby describe the karyotype of the species R. montenegrensis and mainly highlight that the tribe Rhodniini displays karyotypic homogeneity, demonstrating itself as a derived group to a lesser extent when compared to the number of chromosomes of the common ancestors of the subfamily Triatominae.

  15. Triatominae-Trypanosoma cruzi/T. rangeli: Vector-parasite interactions.

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    Vallejo, G A; Guhl, F; Schaub, G A

    2009-01-01

    Of the currently known 140 species in the family Reduviidae, subfamily Triatominae, those which are most important as vectors of the aetiologic agent of Chagas disease, Trypanosoma cruzi, belong to the tribes Triatomini and Rhodniini. The latter not only transmit T. cruzi but also Trypanosoma rangeli, which is considered apathogenic for the mammalian host but can be pathogenic for the vectors. Using different molecular methods, two main lineages of T. cruzi have been classified, T. cruzi I and T. cruzi II. Within T. cruzi II, five subdivisions are recognized, T. cruzi IIa-IIe, according to the variability of the ribosomal subunits 24Salpha rRNA and 18S rRNA. In T. rangeli, differences in the organization of the kinetoplast DNA separate two forms denoted T. rangeli KP1+ and KP1-, although differences in the intergenic mini-exon gene and of the small subunit rRNA (SSU rRNA) suggest four subpopulations denoted T. rangeli A, B, C and D. The interactions of these subpopulations of the trypanosomes with different species and populations of Triatominae determine the epidemiology of the human-infecting trypanosomes in Latin America. Often, specific subpopulations of the trypanosomes are transmitted by specific vectors in a particular geographic area. Studies centered on trypanosome-triatomine interaction may allow identification of co-evolutionary processes, which, in turn, could consolidate hypotheses of the evolution and the distribution of T. cruzi/T. rangeli-vectors in America, and they may help to identify the mechanisms that either facilitate or impede the transmission of the parasites in different vector species. Such mechanisms seem to involve intestinal bacteria, especially the symbionts which are needed by the triatomines to complete nymphal development and to produce eggs. Development of the symbionts is regulated by the vector. T. cruzi and T. rangeli interfere with this system and induce the production of antibacterial substances. Whereas T. cruzi is only

  16. Differentiation between Triatoma arthurneivai and Triatoma wygodzinskyi (Hemiptera: Reduviidae: Triatominae) using cytotaxonomy.

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    Alevi, K C C; Imperador, C H L; Moreira, F F F; Jurberg, J; Azeredo-Oliveira, M T V

    2016-06-20

    Using classic morphometric techniques to examine the head and thorax of Triatoma specimens, researchers identified a possible taxonomic problem involving T. arthurneivai (Lent & Martins) and T. wygodzinskyi (Lent). A recent geometric morphometric study indicated that the insects captured outside the Serra do Cipó region, State of Minas Gerais, Brazil, were T. wygodzinskyi. The misidentification of T. arthurneivai as T. wygodzinskyi could result in several problems associated with entoepidemiological lifting, the biological characterization of the species, and phylogenetic reconstruction. For the first time, we describe the use of cytogenetic analysis as a tool for differentiation between T. arthurneivai and T. wygodzinskyi. The results indicated that both species had the same number of chromosomes 2n = 22 (20A + XY). However, analyses of spermatocytes during early prophase indicated that it was possible to differentiate T. arthurneivai and T. wygodzinskyi, because only T. arthurneivai exhibited heteropycnotic blocks distributed in the chromatin. Therefore, we highlight the analysis of spermatocytes as a taxonomic tool for the characterization of T. arthurneivai and T. wygodzinskyi, and suggest that the technique can be used for entoepidemiological lifting in vector control programs. Thus, the results presented here, in conjunction with morphometric analyses, are of utmost taxonomic and epidemiological importance for the identification of T. arthurneivai and T. wygodzinskyi specimens.

  17. Mitochondrial Genes Reveal Triatoma jatai as a Sister Species to Triatoma costalimai (Reduviidae: Triatominae).

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    Teves, Simone Caldas; Gardim, Sueli; Carbajal de la Fuente, Ana Laura; Lopes, Catarina Macedo; Gonçalves, Teresa Cristina Monte; dos Santos Mallet, Jacenir Reis; da Rosa, João Aristeu; Almeida, Carlos Eduardo

    2016-03-01

    Triatoma jatai was described using a set of morphological structures from specimens collected in Paranã municipality of Tocantins State, Brazil. Under a Bayesian framework and using two mitochondrial genes (16S and COI), phylogenetic analysis recovered T. jatai as a sister species to Triatoma costalimai with higher genetic distances than between other well-recognized species. Our results agree with previous suggestions based on morphometric analysis. In the light of the non-monophyly of Matogrossensis subcomplex, the inclusion of T. jatai shall be considered for reevaluating this group. © The American Society of Tropical Medicine and Hygiene.

  18. Biological, morphological and morphometric studies of Triatoma melanocephala Neiva & Pinto, 1923 (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    De Oliveira, Jader; Mendonça, Vagner J; De Araújo, Renato Freitas; Nascimento, Eliane Góes; Da Rosa, João Aristeu

    2015-09-04

    Triatoma melanocephala Neiva & Pinto is found in the Brazilian states of Bahia, Paraíba, Pernambuco, Rio Grande do Norte, and Sergipe. In addition to the species' specific description, eight other articles on this insect were found in the literature. In this study, data was obtained on the morphology, morphometry, and life cycle of T. melanocephala, since this vector is of epidemiological and taxonomic importance. The specimens studied were obtained from a colony that has been kept at the Triatomine Insectarium of the College of Pharmaceutical Sciences of São Paulo State University's in Brazil. The morphological studies were performed using scanning electron microscopy. These studies characterized the eggs, the external adult female genitalia, and the ninth ventral abdominal segments of male and female nymphs. The morphometric studies characterized the five nymphal instars and the adult stage by measuring the head, thorax, abdomen, antennae, and mouthparts parameters. The life cycle of T. melanocephala was developed starting by 15 couples in the fifth instar. They were fed on Swiss mice every two weeks and observed daily. During daily observation, minimum temperature, maximum temperature, and relative humidity of the laboratory were measured. The results of the biological, morphometric, and morphological studies have increased the knowledge available on T. melanocephala.

  19. Triatoma vitticeps subcomplex (Hemiptera, Reduviidae, Triatominae): a new grouping of Chagas disease vectors from South America.

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    Alevi, Kaio Cesar Chaboli; de Oliveira, Jader; de Azeredo-Oliveira, Maria Tercília Vilela; da Rosa, João Aristeu

    2017-04-13

    Triatomines have been grouped into complexes and subcomplexes based largely on morphological and geographical distribution. Although these groupings are not formally recognised as taxonomic ranks, they are likely monophyletic. However, recent studies have demonstrated that some subcomplexes from South America did not form monophyletic groups, and reorganisations have been suggested. One suggested reorganisation is to exclude Triatoma vitticeps, T. melanocephala, and T. tibiamaculata from the T. brasiliensis subcomplex. However, T. vitticeps and T. melanocephala exhibit several similar characteristics, including morphologic, cytogenetic, and phylogenetic features, a factor which supports the creation of a new subcomplex. Thus, this study aimed to describe the T. vitticeps subcomplex. T. vitticeps and T. melanocephala are sister species and share a phylogenetic relationship, several similar morphological characteristics, the same composition of constitutive heterochromatin (Xs CG-rich and Y AT-rich), the same karyotype (2n = 20A + X 1 X 2 X 3 Y), and the same meiotic behaviour during spermatogenesis. Based on karyosystematics, for example, the T. vitticeps subcomplex may differ from all of the other subcomplexes from South America, as well as from the Rhodniini tribe and the genus Panstrongylus. We argue that the case of agmatoploidy involving the X chromosome was responsible for the karyotype divergence of this subcomplex in relation to the other South America subcomplexes. Based on the phenotypic characteristics (morphology) and genotypes (cytogenetics and molecular features), we propose the creation of the monophyletic T. vitticeps subcomplex, which we believe is distinct from all other subcomplexes from South America.

  20. Sexual distinction between 5th instar nymphs of six species of Triatominae (Hemiptera, Reduviidae

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    João Aristeu da Rosa

    1992-06-01

    Full Text Available The aim of this paper is to present the analysis of sexual morphological differences observed in 5th instar nymphs of the following species: Panstrongylus megistus; Rhodnius neglectus; Triatoma brasiliensis; T. infestans; T. matogrosensis and T. tibiamaculata. Male and female nymphs were examined and photographed with a Scanning Electron Microscope. The 9th segment dimensions of dorsal and ventral faces were determined through a Profile Projector. Results and statistical analysis showed significant differences: the 9th sternite is significantly broader in male than female nymphs, while in five species; tergites in female nymphs are broad and in male are narrow.

  1. Geographic distribution and morphometric differentiation of Triatoma nitida usinger 1939 (Hemiptera: Reduviidae: Triatominae in Guatemala

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    Monroy Carlota

    2003-01-01

    Full Text Available Triatoma nitida was found in 14 (0.4% out of 3,726 houses located in six departments across Guatemala, which were surveyed from 1994 to 1998 by the man-hour collection method. Compared to previous information, the distribution of T. nitida in Guatemala has increased from five to nine departments; the species is present in mild climates at altitudes from 960 to 1,500 m. Fourteen percent of the intradomestic T. nitida were infected with Trypanosoma cruzi. The species was often found in conjunction with other triatomines (T. dimidiata and Rhodnius prolixus. The domestic and peridomestic presence of T. nitida in Guatemala was rare, but occasionally this species was colonizing human-made constructions. T. nitida appears to have a low importance as Chagas disease vector in Guatemala, as indicated by its scarce presence in the domestic habitats and defecation patterns. However, it clearly has potential to become a Chagas vector so we recommend an on-going study of the intradomestic presence of T. nitida following the control programs in Guatemala. Morphometric analysis of 47 T. nitida males from three localities showed quantitative differences between the populations, which indicates that geographic distance is an important factor in the structuring of T. nitida populations.

  2. Triatoma jatai sp. nov. in the state of Tocantins, Brazil (Hemiptera: Reduviidae: Triatominae)

    Science.gov (United States)

    Gonçalves, Teresa Cristina Monte; Teves-Neves, Simone Caldas; dos Santos-Mallet, Jacenir Reis; Carbajal-de-la-Fuente, Ana Laura; Lopes, Catarina Macedo

    2013-01-01

    Triatoma jatai sp. nov. is the first new species of triatomine to be described in the state of Tocantins, in the northern region of Brazil. It was caught on rock outcrops in the wild environment and, more recently, invading homes. While T. jatai sp. nov. is morphologically similar to Triatoma costalimai, it is distinguished by its general colouring, differences in the blotches on the connexivum, wing size in females and external structures of the male genitalia. The type series has been deposited in the Entomological Collection and Herman Lent Collection, Oswaldo Cruz Institute-Oswaldo Cruz Foundation, Rio de Janeiro, Brazil. PMID:23828010

  3. Diversidad de Triatominae (Hemiptera: Reduviidae en Santander, Colombia: implicaciones epidemiológicas

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    Lyda Esteban

    2017-01-01

    Conclusiones. Los resultados evidenciaron diferencias en la diversidad de las dos regiones, además del potencial de las especies silvestres para ocupar ecótopos artificiales. La intrusión de triatominos y la reciente incriminación de especies silvestres en la transmisión de Trypanosoma cruzi, indican la necesidad de un mayor conocimiento de la ecología de estos vectores para orientar las estrategias de control.

  4. Rhodnius barretti, a new species of Triatominae (Hemiptera: Reduviidae) from western Amazonia

    Science.gov (United States)

    Abad-Franch, Fernando; Pavan, Márcio G; Jaramillo-O, Nicolás; Palomeque, Francisco S; Dale, Carolina; Chaverra, Duverney; Monteiro, Fernando A

    2013-01-01

    Rhodnius barretti , a new triatomine species, is described based on adult specimens collected in rainforest environments within the Napo ecoregion of western Amazonia (Colombia and Ecuador). R. barretti resembles Rhodnius robustus s.l. , but mitochondrial cytochrome b gene sequences reveal that it is a strongly divergent member of the “robustus lineage”, i.e., basal to the clade encompassing Rhodnius nasutus , Rhodnius neglectus , Rhodnius prolixus and five members of the R. robustus species complex. Morphometric analyses also reveal consistent divergence from R. robustus s.l. , including head and, as previously shown, wing shape and the length ratios of some anatomical structures. R. barretti occurs, often at high densities, in Attalea butyracea and Oenocarpus bataua palms. It is strikingly aggressive and adults may invade houses flying from peridomestic palms. R. barretti must therefore be regarded as a potential Trypanosoma cruzi vector in the Napo ecoregion, where Chagas disease is endemic. PMID:24473808

  5. Description of Rhodnius marabaensis sp. n. (Hemiptera, Reduviidae, Triatominae) from Pará State, Brazil

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    Souza, Eder dos Santos; Von Atzingen, Noé Carlos Barbosa; Furtado, Maria Betânia; de Oliveira, Jader; Nascimento, Juliana Damieli; Vendrami, Daniel Pagotto; Gardim, Sueli; da Rosa, João Aristeu

    2016-01-01

    Abstract Rhodnius marabaensis sp. n. was collected on 12 May 2014 in the Murumurú Environmental Reserve in the city of Marabá, Pará State, Brazil. This study was based on previous consultation of morphological descriptions of 19 Rhodnius species and compared to the identification key for the genus Rhodnius. The examination included specimens from 18 Rhodnius species held in the Brazilian National and International Triatomine Taxonomy Reference Laboratory in the Oswaldo Cruz Institute in Rio de Janeiro, Brazil. The morphological characteristics of the head, thorax, abdomen, genitalia, and eggs have been determined. Rhodnius prolixus and Rhodnius robustus were examined in more detail because the BLAST analysis of a cyt-b sequence shows they are closely related to the new species, which also occurs in the northern region of Brazil. The most notable morphological features that distinguish Rhodnius marabaensis sp. n. are the keel-shaped apex of the head, the length of the second segment of the antennae, the shapes of the prosternum, mesosternum and metasternum, the set of spots on the abdomen, the male genitalia, the posterior and ventral surfaces of the external female genitalia, and the morphological characteristics of the eggs. Rhodnius jacundaensis Serra, Serra & Von Atzingen (1980) nomen nudum specimens deposited at the Maraba Cultural Center Foundation - MCCF were examined and considered as a synonym of Rhodnius marabaensis sp. n. PMID:27833419

  6. Isoenzymes detect variation in populations of Triatoma brasiliensis (Hemiptera: Reduviidae: Triatominae).

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    Costa, J; Freitas-Sibajev, M G; Marchon-Silva, V; Pires, M Q; Pacheco, R S

    1997-01-01

    Triatoma brasiliensis is one of the most important vectors of Chagas disease in the semiarid zone of the northeast of Brazil. Intraspecific morphological and behavioural variation has been reported for different populations. Results for four distinct populations using eight isoenzymes are reported here. The literature describes three subspecies: T. brasiliensis brasiliensis Neiva, 1911; T. brasiliensis melanica Neiva & Lent, 1941 and T. brasiliensis macromelasoma Galvão, 1956. These subspecies differ mainly in their cuticle colour pattern and were regarded as synonyms by Lent and Wygodzinsky (1979). In order to evaluate whether the chromatic pattern is a morphological variation of different melanic forms within T. brasiliensis or due to interspecific variation, field collections were performed in localities where these three subspecies have been described: Caicó (Rio Grande do Norte), the type-locality for T. b. brasiliensis; Petrolina (Pernambuco) for T. b. macromelasoma and Espinosa (Minas Gerais) for T. b. melanica. A fourth distinct chromatic pattern was found in Juazeiro (Bahia). A total of nine loci were studied. Values of Nei's genetic distance (D) were calculated. T. b. brasiliensis and T. b. macromelasoma are the closest populations with a D = 0.295. T. b. melanica had a D > or = 0.537 when compared to the others, a distance in the range of interspecific variation for other triatomine species.

  7. Ecotopes, natural infection and trophic resources of Triatoma brasiliensis (Hemiptera, Reduviidae, Triatominae).

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    Costa, J; de Almeida, J R; Britto, C; Duarte, R; Marchon-Silva, V; Pacheco, R da S

    1998-01-01

    Triatoma brasiliensis is considered as one of the most important Chagas disease vectors in the northeastern Brazil. This species presents chromatic variations which led to descriptions of subspecies, synonymized by Lent and Wygodzinsky (1979). In order to broaden bionomic knowledge of these distinct colour patterns of T. brasiliensis, captures were performed at different sites, where the chromatic patterns were described: Caicó, Rio Grande do Norte (T. brasiliensis brasiliensis Neiva, 1911), it will be called the "brasiliensis population"; Espinosa, Minas Gerais (T. brasiliensis melanica Neiva & Lent 1941), the "melanica population" and Petrolina, Pernambuco (T. brasiliensis macromelasoma, Galvão 1956), the "macromelasoma population". A fourth chromatic pattern was collected in Juazeiro, Bahia the darker one in overall cuticle coloration, the "Juazeiro population". At the sites of Caicó, Petrolina and Juazeiro, specimens were captured in peridomiciliar ecotopes and in wilderness. In Espinosa the specimens were collected only in wilderness, even though several exhaustive captures have been performed in peridomicile at different sites of this municipality. A total of 298 specimens were captured. The average registered infection rate was 15% for "brasiliensis population" and of 6.6% for "melanica population". Specimens of "macromelasoma" and of "Juazeiro populations" did not present natural infection. Concerning trophic resources, evaluated by the precipitin test, feeding eclecticism for the different colour patterns studied was observed, with dominance of goat blood in household surroundings as well as in wilderness.

  8. A genitália externa na tribo Bolboderini (Hemiptera, Reduviidae, Triatominae

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    Herman Lent

    1984-03-01

    Full Text Available Sete espécies da tribo bolboderini, pertencentes aos gêneros Bolbodera, Belminus, Microtriatoma e Parabelminus, duas das quais já encontradas naturalmente infectadas com Trypanosoma cruzi, foram analisadas e comparadas tendo como enfoque oito estruturas da genitália externa dos machos: Processo mediano do pigóforo (PrP, Processo da conjuntiva (PrCj, Extensão mediana da placa basal (EPIb, Processo do endosoma (PrEn, Suporte do falosoma (SPh, Falosoma (Ph, Processo do gonoporo (PrG e a Vesica (V. Microtriatoma trinidadensis (lent, 1951 e M. borbai Lent & Wygodzinsky, 1979 mostraram um plano estrutural morfológico semelhante a Parabelminus yurupucu Lent & Wygodzinsky, 1979 e P. carioca Lent, 1943 e deferindo nitidamente de Belminus peruvianus Herrer, Lent & Wygodzinsky, 1954 e B. herreri Lent & Wygodzinsky, 1979 e de Bolbodera scabrosa, Valdés, 1910, não só pela ausência como pela forma de determinadas estruturas. Estas observações comparativas confirmam as afinidades entre Microtriatoma e Parabelminus e suas relações com belminus e Bolbodera.Seven species of the Bolboderini tribe belonging to the genera bolbodera, Belminus, Microtriatoma and Parabelminus, two of them found naturally infected with Trypanosoma cruzi, were analysed and compared emphasizing eight structures of the male external genitalia: median process of pygophore (PrP, conjunctiva process (PrCj, pedicel (EP1b, endosoma process (PrEn, struts (SPh, phallosoma (Ph, medium bridge (PrG and vesica (V. Microtriatoma trinidadensis (Lent, 1951 and M. borbai Lent & Wygodzinsky, 1979 have shown a structural morphological aspect similar to Parabelminus yurupucu Lent & Wygodzinsky, 1979 and P. carioca Lent, 1943 differing clearly from Belminus peruvianus Herrer, Lent & Wygodzinsky, 1954, B. herreri Lent & Wygodzinsky, 1979 and Bolbodera scabrosa valdés, 1910, not only by the absence but by the shape of some structures. These comparative observations confirm the affinity between Microtriatoma and Parabelminus and their relations with Belminus and Bolbodera.

  9. [Triatoma dimidiata populations' (Hemiptera: Reduviidae: Triatominae) feeding behaviour in an endemic zone and related epidemiological implications].

    Science.gov (United States)

    Farfán-García, Ana E; Angulo-Silva, Víctor M

    2011-02-01

    Determining Triatoma dimidiata's feeding behaviour in domiciliary and extra-domiciliary habitats in an endemic area of the Santander department in Colombia. The ELISA technique was used for processing the intestinal contents of 367 insects captured in rural areas around the municipalities of Capitanejo and Macaravita. 12 anti-animal species specific polyclonal anti-sera were used in ELISA. T. dimidiata hosts were determined by reactivity to each anti-serum; host percentages were established. 42.2% of the intestinal content processed by ELISA was reactive for blood proteins from one or more than 10 hosts. Domestic animal proteins were identified in all reactive intra-domiciliary and peridomestic insects, most often chicken blood, followed by that from goats, canines and humans. Blood from domestic animals like goats, chicken and horses was also detected in wild insects. Blood from animals such as armadillo and fara were identified in intra-domiciliary insects. Human host protein was found in 11% of intra-domiciliary and peri-domiciliary insects. The vector's eclectic nature in domiciliary and extra-domiciliary habitats was determined by identifying human blood in wild and domestic animals. The wild populations' mobility towards domiciliary and peri-domiciliary areas was demonstrated by finding domestic animals' blood in them and wild animals' blood in domestic and peri-domestic insects. These results contribute towards understanding Trypanosoma cruzi transmission-cycles.

  10. Third record of Rhodnius amazonicus and comparative study with R. pictipes (Hemiptera, Reduviidae, Triatominae).

    Science.gov (United States)

    da Rosa, João Aristeu; Souza, Eder Santos; da Costa Teixeira, Adelson; Barbosa, Rosenildo Ribeiro; de Souza, Aecildo José; Belintani, Tiago; Nascimento, Juliana Damieli; Gil-Santana, Hélcio Reinaldo; de Oliveira, Jader

    2017-12-01

    Rhodnius amazonicus Almeida et al. (1973) is a triatomine of rare occurrence. This species was found for the third time in Breves city, Pará state, Brazil. Morphometric and morphological studies were carried out on one male and one female. Lent and Wygodzinsky (1979) considered this species as a synonym of R. pictipes, until its revalidation after 23 years by Bérenger and Pluot-Sigwalt (2002). Considering the synonym mentioned above, a comparative study between these two species was performed in order to report the third encounter of this species, and increase the number of morphological characters that distinguish R. amazonicus from R. pictipes. The dorsal side of the head, the dorsal and ventral portions of the thorax, the dorsal, ventral and posterior sides of the female genitalia, eggs and the median process of the pygophore were examined by scanning electronic microscopy (SEM). The head, thorax, abdomen and egg parameters of these two species were also measured. The identification of characters on the head, stridulatory sulcus, mesosternum, metasternum, scutellum, process of urotergite I, external female genitalia, pygophore and eggs made the distinction between R. amazonicus and R. pictipes possible. This study has shown the new characters recorded and described for the first time for R. amazonicus and R. pictipes by SEM here made it possible to confirm the morphological separation between these two species. The morphometric analysis also confirmed that the above two taxa are different at specific level. Copyright © 2017. Published by Elsevier B.V.

  11. Cytotaxonomy of the Brasiliensis subcomplex and the Triatoma brasiliensis complex (Hemiptera: Reduviidae: Triatominae).

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    Alevi, Kaio C C; Rosa, João A; Azeredo-Oliveira, Maria Tercília V

    2014-07-22

    We analyzed the classical cytotaxonomy of the Brasiliensis subcomplex (Triatoma brasiliensis Neiva, T. juazeirensis Costa & Felix, T. melanica Costa, Argolo & Felix, T. melanocephala Neiva & Pinto, T. petrochiae Pinto & Barreto, T. lenti Sherlock & Serafim, T. sherlocki Papa, Jurberg, Carcavallo, Cerqueira & Barata, T. tibiamaculata Pinto and T. vitticeps Stal) and the T. brasiliensis complex (T. b. brasiliensis, T. b. macromelasoma Neiva & Lent, T. juazeirensis, T. melanica and T. sherlocki). The five members of the T. brasiliensis complex share the same cytogenetic characteristics. Merely T. sherlocki show differences in spermatids, which confirms the status of more differentiated member of the complex. T. lenti also presented the same cytogenetic characteristics described for the species of the T. brasiliensis complex, which supports possible grouping of the species as sixth member of the complex, although further analysis as molecular and experimental crosses are needed to corroborate this hypothesis. T. petrochiae, T. vitticeps, T. tibiamaculata and T. melanocephala presented one or more characteristics that allow questioning grouping in the proposed Brasiliensis subcomplex. Thus, we suggested that Brasiliensis subcomplex and T. brasiliensis complex should be constituted by the same triatomines (T. b. brasiliensis, T. b. macromelasoma, T. juazeirensis, T. melanica and T. sherlocki). However, we draw attention to T. lenti and suggest that although new analyzes should be performed, possibly this species is the sixth member of the T. brasiliensis complex. 

  12. Biological and genetic aspects of experimental hybrids from species of the Phyllosoma complex (Hemiptera: Reduviidae: Triatominae).

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    Martínez-Ibarra, José Alejandro; Ventura-Rodríguez, Luz Verónica; Meillon-Isais, Karla; Barajas-Martínez, Héctor; Alejandre-Aguilar, Ricardo; Lupercio-Coronel, Patricia; Rocha-Chávez, Gonzalo; Nogueda-Torres, Benjamín

    2008-05-01

    The present work is a thorough investigation of the degree of reproductive isolation between Meccus mazzottii and Meccus longipennis, Meccus picturatus, Meccus pallidipennis and Meccus bassolsae, as well as between M. longipennis and M. picturatus. We examined fertility and segregation of morphological characteristics in two generations of hybrids derived from crosses between these species. The percentage of pairs with (fertile) offspring was highest in the set of crosses between M. longipennis and M. picturatus, and lowest between M. mazzottii and M. picturatus. Most first-generation (F1) individuals from crosses involving M. mazzottii were morphologically similar to this species, while only F1 x F1 progeny of parental crosses between M. mazzottii and M. longipennis had offspring second generation that looked like M. mazzottii. The results indicate that different degrees of reproductive isolation apparently exist among the species of the Phyllosoma complex examined in this study. The biological evidence obtained in this study does not support the proposal that M. longipennis and M. picturatus are full species. It could indicate on the contrary, that both could be considered as subspecies of a single polytypic species. On the other hand, biological evidence supports the proposal that M. mazzottii is a full species.

  13. Ecological patterns of blood-feeding by kissing-bugs (Hemiptera: Reduviidae: Triatominae).

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    Rabinovich, Jorge Eduardo; Kitron, Uriel Dan; Obed, Yamila; Yoshioka, Miho; Gottdenker, Nicole; Chaves, Luis Fernando

    2011-06-01

    Host use by vectors is important in understanding the transmission of zoonotic diseases, which can affect humans, wildlife and domestic animals. Here, a synthesis of host exploitation patterns by kissing-bugs, vectors of Chagas disease, is presented. For this synthesis, an extensive literature review restricted to feeding sources analysed by precipitin tests was conducted. Modern tools from community ecology and multivariate statistics were used to determine patterns of segregation in host use. Rather than innate preferences for host species, host use by kissing-bugs is influenced by the habitats they colonise. One of the major limitations of studies on kissing-bug foraging has been the exclusive focus on the dominant vector species. We propose that expanding foraging studies to consider the community of vectors will substantially increase the understanding of Chagas disease transmission ecology. Our results indicate that host accessibility is a major factor that shapes the blood-foraging patterns of kissing-bugs. Therefore, from an applied perspective, measures that are directed at disrupting the contact between humans and kissing-bugs, such as housing improvement, are among the most desirable strategies for Chagas disease control.

  14. Biological and genetic aspects of crosses between species of the genus Meccus (Hemiptera: Reduviidae Triatominae).

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    Martínez-Ibarra, José Alejandro; Grant-Guillén, Yunuen; Ventura-Rodríguez, Luz Verónica; Osorio-Pelayo, Paola Denisse; Macías-Amezcua, Michael Dassaejv; Meillón-Isáis, Karla; Alejandre-Aguilar, Ricardo; Rodríguez-Bataz, Elvia; Nogueda-Torres, Benjamín

    2011-05-01

    The degree of reproductive isolation between Meccus phyllosomus and the remaining five species of the genus Meccus, as well as between Meccus bassolsae and Meccus pallidipennis, Meccus longipennis and Meccus picturatus, was examined. Fertility and the segregation of morphological characteristics were examined in two generations of hybrids from crosses between these species. The percentage of couples with offspring (fertile) was high in the vast majority of sets of crosses, with the exception of that between ♀M. phyllosomus and ♂Meccus mazzottii. In sets of crosses involving M. bassolsae specimens, no first-generation (F1) individuals were morphologically similar to M. bassolsae, but instead shared the morphology of the other parental species. A similar phenomenon was observed in most sets of crosses involving M. phyllosomus. These results indicated that different degrees of reproductive isolation exist among the species of Meccus involved in this study. The biological evidence obtained in this study does not support the proposal that M. bassolsae is a full species. It could indicate that, on the contrary, it should be considered a subspecies of a single polytypic species. The biological evidence does support the proposal that M. phyllosomus is a full species.

  15. Population genetic structure of Meccus longipennis (Hemiptera, Reduviidae, Triatominae), vector of Chagas disease in West Mexico.

    Science.gov (United States)

    Brenière, Simone Frédérique; Waleckx, Etienne; Magallón-Gastélum, Ezequiel; Bosseno, Marie-France; Hardy, Xavier; Ndo, Cyrille; Lozano-Kasten, Felipe; Barnabé, Christian; Kengne, Pierre

    2012-03-01

    The originally wild species of the Meccus complex are important vectors of Chagas disease in Mexico. In West Mexico, Meccus longipennis plays an important epidemiological role. To understand the genetic structure of the domestic and wild populations of this species, a preliminary study with five polymorphic microsatellite loci was conducted. The population genetics analysis showed high structuring between peridomestic biotopes, with breeding subunits detected in a single peridomestic structure. In the wild environment, two genetic patterns were observed according to the biotope, possible breeding subunits in large rocky formations and a larger panmictic unit in agropastoral areas, suggesting considerable dispersal of bugs in this biotope. Moreover, the discovery of two foci of wild populations at the edge of Guadalajara city raises the question of new urban areas where the phenomenon of bug incursions into households could constitute a risk of transmission of Chagas disease. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Estudo morfológico de Triatoma guazu Lent & Wygodzinsky, 1979 (Hemiptera, Reduviidae, Triatominae

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    Galindez-Girón Itamar

    1997-01-01

    Full Text Available A female of Triatoma guazu Lent & Wygodzinsky, 1979, a rare species from which the allotype was recently described, was studied by scanning electronic microscopy and videomicroscope. Some structures of the head and the thorax are shown. Some of them could have taxonomic importance, as the oculo-ocellar region, the buccula, the anterolateral angle of the collar, the scutellum, wings and the stridulatory sulcus, which has an unusual lateral high rim

  17. Triatoma jatai sp. nov. in the state of Tocantins, Brazil (Hemiptera: Reduviidae: Triatominae

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    Teresa Cristina Monte Goncalves

    2013-06-01

    Full Text Available Triatoma jatai sp. nov. is the first new species of triatomine to be described in the state of Tocantins, in the northern region of Brazil. It was caught on rock outcrops in the wild environment and, more recently, invading homes. While T. jatai sp. nov. is morphologically similar to Triatoma costalimai, it is distinguished by its general colouring, differences in the blotches on the connexivum, wing size in females and external structures of the male genitalia. The type series has been deposited in the Entomological Collection and Herman Lent Collection, Oswaldo Cruz Institute-Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.

  18. Ecotopes, Natural Infection and Trophic Resources of Triatoma brasiliensis (Hemiptera, Reduviidae, Triatominae

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    Jane Costa

    1998-01-01

    Full Text Available Triatoma brasiliensis is considered as one of the most important Chagas disease vectors in the northeastern Brazil. This species presents chromatic variations which led to descriptions of subspecies, synonymized by Lent and Wygodzinsky (1979. In order to broaden bionomic knowledge of these distinct colour patterns of T. brasiliensis, captures were performed at different sites, where the chromatic patterns were described: Caicó, Rio Grande do Norte (T. brasiliensis brasiliensis Neiva, 1911, it will be called the "brasiliensis population"; Espinosa, Minas Gerais (T. brasiliensis melanica Neiva & Lent 1941, the "melanica population" and Petrolina, Pernambuco (T. brasiliensis macromelasoma, Galvão 1956, the "macromelasoma population". A fourth chromatic pattern was collected in Juazeiro, Bahia the darker one in overall cuticle coloration, the "Juazeiro population". At the sites of Caicó, Petrolina and Juazeiro, specimens were captured in peridomiciliar ecotopes and in wilderness. In Espinosa the specimens were collected only in wilderness, even though several exhaustive captures have been performed in peridomicile at different sites of this municipality. A total of 298 specimens were captured. The average registered infection rate was 15% for "brasiliensis population" and of 6.6% for "melanica population". Specimens of "macromelasoma" and of "Juazeiro populations" did not present natural infection. Concerning trophic resources, evaluated by the precipitin test, feeding eclecticism for the different colour patterns studied was observed, with dominance of goat blood in household surroundings as well as in wilderness

  19. Rhodnius barretti, a new species of Triatominae (Hemiptera: Reduviidae) from western Amazonia.

    Science.gov (United States)

    Abad-Franch, Fernando; Pavan, Márcio G; Jaramillo-O, Nicolás; Palomeque, Francisco S; Dale, Carolina; Chaverra, Duverney; Monteiro, Fernando A

    2013-01-01

    Rhodnius barretti, a new triatomine species, is described based on adult specimens collected in rainforest environments within the Napo ecoregion of western Amazonia (Colombia and Ecuador). R. barretti resembles Rhodnius robustus s.l., but mitochondrial cytochrome b gene sequences reveal that it is a strongly divergent member of the "robustus lineage", i.e., basal to the clade encompassing Rhodnius nasutus, Rhodnius neglectus, Rhodnius prolixus and five members of the R. robustus species complex. Morphometric analyses also reveal consistent divergence from R. robustus s.l., including head and, as previously shown, wing shape and the length ratios of some anatomical structures. R. barretti occurs, often at high densities, in Attalea butyracea and Oenocarpus bataua palms. It is strikingly aggressive and adults may invade houses flying from peridomestic palms. R. barretti must therefore be regarded as a potential Trypanosoma cruzi vector in the Napo ecoregion, where Chagas disease is endemic.

  20. Triatoma sordida Stål 1859 (Hemiptera, Reduviidae: Triatominae in palms of northeastern Argentina

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    Bar María Esther

    2001-01-01

    Full Text Available Several palms species provide an important habitat for triatomines and associate vertebrates in tropical America. The objective of this work is to identify the triatomine species living in the palms of rural areas in the Province of Corrientes, and to estimate the potential epidemiological risk they represent for the residents of nearby houses. The survey was carried out in a palm community in Colonia Laurel, Department San Roque, Province of Corrientes, Argentina. Samplings were performed in October, November and December 1998; January, February and March 1999; May and June 1999. Thirty palms: 27 (90% Butia yatay (Mart. Becc. and 3 Acrocomia aculeata (Jacq. Lodd ex Mart. were dissected. Triatoma sordida Stål 1859 was found in 96.2% of B. yatay and in all the A. aculeata palms. A total of 272 live T. sordida was collected; 36 of them (13.2% were found in bird nests in the frond and the remainder in other locations of the tree. The mean number of triatomines per palm was 9.6 (range 1-60, mode 2. T. sordida was collected during all the sampling months and all stages were present at all seasons. The highest population density was reached in spring and the lowest in autumn. Trypanosoma cruzi was detected in 38.5% in feces of 174 examined insects and identified as such, both by microscopical examination and PCR. This is the first finding of T. sordida populations in B. yatay, an endemic palm of South America distributed in southern Brazil, Uruguay and northeastern Argentina. The high infection prevalence found in this work suggests that T. sordida plays an essential role in the maintenance of the wild T. cruzi transmission cycle in northeastern Argentina.

  1. Cathepsin L of Triatoma brasiliensis (Reduviidae, Triatominae): sequence characterization, expression pattern and zymography.

    Science.gov (United States)

    Waniek, Peter J; Pacheco Costa, Juliana E; Jansen, Ana M; Costa, Jane; Araújo, Catarina A C

    2012-01-01

    Triatoma brasiliensis is considered one of the main vectors of Chagas disease commonly found in semi-arid areas of northeastern Brazil. These insects use proteases, such as carboxypeptidase B, aminopeptidases and different cathepsins for blood digestion. In the present study, two genes encoding cathepsin L from the midgut of T. brasiliensis were identified and characterized. Mature T. brasiliensis cathepsin L-like proteinases (TBCATL-1, TBCATL-2) showed a high level of identity to the cathepsin L-like proteinases of other insects, with highest similarity to Rhodnius prolixus. Both cathepsin L transcripts were highly abundant in the posterior midgut region, the main region of the blood digestion. Determination of the pH in the whole intestine of unfed T. brasiliensis revealed alkaline conditions in the anterior midgut region (stomach) and acidic conditions in the posterior midgut region (small intestine). Gelatine in-gel zymography showed the activity of at least four distinct proteinases in the small intestine and the cysteine proteinase inhibitors transepoxysuccinyl-l-leucylamido-(4-guanidino)butane (E-64) and cathepsin B inhibitor and N-(l-3-trans-propylcarbamoyl-oxirane-2-carbonyl)-l-isoleucyl-l-proline (CA-074) were employed to characterize enzymatic activity. E-64 fully inhibited cysteine proteinase activity, whereas in the samples treated with CA-074 residual proteinase activity was detectable. Thus, proteolytic activity could at least partially be ascribed to cathepsin L. Western blot analysis using specific anti cathepsin L antibodies confirmed the presence of cathepsin L in the lumen of the small intestine of the insects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Resistance to Starvation of Triatoma rubrofasciata (De Geer, 1773 under Laboratory Conditions (Hemiptera: Reduviidae: Triatominae

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    Rojas Cortéz Mirko G

    1998-01-01

    Full Text Available The present work aims at learning the period of resistance to starvation (molting/death of Triatoma rubrofasciata in different stages of development and the respective loss of weight until death. Eggs of specimens from the greater area of the city of São Luis in the State of Maranhão, Brazil, yielded approximately 300 nymphs. These nymphs were placed in labelled Borrel glasses, in which they were weekly fed on rats (Rattus norvegicus, until reaching the stage to be observed. The experiments were conducted in a climatic chamber regulated at 29 ± 1° C, 70% relative humidity and 12 hr photoperiod. The resistance to starvation increased according to the stage of development, except for adult bugs, whose results were similar to the 3rd stage nymphs. In all these development stages there was an abrupt loss of weight in the first week, followed by a gradual loss until death. Comparing this work with those of other authors, it was observed that T. rubrofasciata is among the less resistant triatomine species.

  3. Resistance to starvation of Rhodnius neivai Lent, 1953 (Hemiptera: Reduviidae: Triatominae under experimental conditions

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    Daniel R Cabello

    2001-05-01

    Full Text Available The period of resistance to starvation and the loss of weight until death of Rhodnius neivai in all stages of development were studied. Work was based on experiments conducted under controlled laboratory conditions. One hundred specimens of each nymphal instar were observed: 50 were fed on chicken and 50 on rabbit. Adult females and males were kept together and fed on each host. All bugs were weighed weekly until death. Laid eggs were collected weekly and observed during five weeks to obtain hatchability. Resistance to starvation was similar with both hosts and increased with the evolutionary stage, excepting the 5th nymphal instar and adults. With both hosts, loss of weight was abrupt in the first week and steady in the following weeks. In adults, on the first weeks after eating, there was little or no mortality, after which mortality increased rapidly with the starving time. Reproductive output was higher in the bugs fed on rabbit. R. neivai is among the least resistant triatomine species.

  4. A revision of thirteen species of Triatominae (Hemiptera: Reduviidae vectors of Chagas disease in Mexico

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    Salazar-Schettino Paz Maria

    2010-10-01

    Full Text Available Vectors of Trypanosoma cruzi, parasite responsible for Chagas disease, are divided in intradomestic, peridomestic and sylvatic. The intradomestic are Triatoma barberi and Triatoma dimidiata, two species that represent the highest health risk among the Mexican population. Triatoma dimidiata is a species found mainly inside human habitats, but in Yucatan, it corresponds to the peridomicile vectors. Also in the peridomicile most of Chagas disease vectors are found: Meccus bassolsae, M. longipennis, M. mazzottii, M pallidipennis, M. phyllosomus, M picturata, Triatoma gerstaeckeri, T mexicana, T rubida, Dipetalogaster máxima (the last two are in the process of becoming adapted to the domicile, Panstrongylus rufotuberculatus which occasionally enters the domicile in its adult stage, and Rhodnius prolixus, which is practically controlled in the country. Peridomestic vectors are of lower risk in the transmission dynamics, as compared to the intradomestic ones. For the control of the intradomestic vectors, health education programs, improvements of housing, and the use of pesticides are essential To control the peridomestic vectors, health education programs are required, as well as the use of mosquito nets on doors and windows and around beds, aside from cementing the stone wall fences.

  5. Chromosome homogeneity in populations of Triatoma brasiliensis Neiva 1911 (Hemiptera - Reduviidae - Triatominae

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    Panzera Francisco

    2000-01-01

    Full Text Available Triatoma brasiliensis is the most important vector of Chagas disease in the semiarid zone of the Northeast of Brazil. Several authors have reported the occurrence of four chromatic patterns with morphological, ecological, and genetic differences. In order to determine the existence of cytogenetic differentiation between these chromatic forms, we analyzed their karyotypes and the chromosome behavior during the male meiotic process. Triatoma brasiliensis shows distinct and specific chromosome characteristics, which differ from those observed in all other triatomine species. However, no cytogenetic differences were observed between the four chromatic forms of T. brasiliensis. The lack of chromosome differentiation among them could indicate that the populations of this species are in a process of differentiation that does not involve their chromosomal organization.

  6. Feeding, defecation, and development times of Meccus longipennis Usinger, 1939 (Hemiptera: Reduviidae: Triatominae under laboratory conditions

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    José Alejandro Martínez-Ibarra

    2003-10-01

    Full Text Available Aspects related to hatching, time-lapse between presenting the blood-meal and beginning of feeding, feeding time, postfeed defecation delay, mortality, and fecundity for each stage of Meccus longipennis life-cycle were evaluated. The bugs were maintained in a dark incubator at 27 ± 1ºC and 80 ± 5% rh, were fed weekly and checked daily for ecdysis or death. The hatching rate observed for 300 eggs was 76.7% and the average time of hatching was 19.8 days. Mean time-lapse between presentation of the blood meal and the beginning of feeding was under 5 min in nymphal stages and postfeed defecation delay was under 10 min in most stages, except in fourth and fifth stages. Mean feeding time was longer than 10 min in most stages, except in fourth stage. One hundred thirty-one nymphs (N (65.5% completed the cycle and the average time from NI to adult was 192.6 ± 34.8 days. The average span in days for each stage was 18.1 for NI, 21.4 for NII, 29.5 for NIII, 45.5 for NIV and 55.9 for NV. The number of bloodmeals at each nymphal stage varied from 1 to 5. The mortality rate was 3.29 for NI, 6.8 for NII, 2.92 for NIII 3.76 for NIV, and 10.16 for NV nymphs. The average number of eggs laid per female in a 9-month period was 615.6. Based on our results, we conclude that M. longipennis has some biological and behavioral characteristics which influence its capacity of becoming infected and transmitting Trypanosoma cruzi to human populations in those areas of Mexico where it is currently present.

  7. Preliminary results of random amplification of polymorphic DNA among Triatominae of the phyllosoma complex (Hemiptera, Reduviidae

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    Brenière Simone F

    2003-01-01

    Full Text Available In Mexico, Triatoma longipennis (Usinger, Triatoma picturata (Usinger, and Triatoma pallidipennis (Stal, primary Chagas disease vector species of the phyllosoma complex, were analyzed by randomly amplified polymorphic DNA (RAPD. Sixteen decametric primers resolved individual profiles not identical, but partially discriminative between species. Analysis based on pairwise presence/absence comparisons between the three species was performed using three primers and two outgroup species Triatoma infestans (Klug and Triatoma barberi (Usinger. Fifty-three bands in total were scored, although only two bands were constant among the three phyllosoma complex species. Two other bands were constant only for T. longipennis and T. picturata together, and not present in T. pallidipennis. Neighbor Joining tree and the multiple correspondence analysis discriminated T. pallidipennis clearly from the other two species, although there was overlap between T. longipennis and T. picturata. The results indicate a close relationship between the studied species and support the hypothesis of their recent evolution. The suitability of RAPD to discern populations within the species is discussed.

  8. Differential transcriptome analysis supports Rhodnius montenegrensis and Rhodnius robustus (Hemiptera, Reduviidae, Triatominae as distinct species.

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    Danila Blanco de Carvalho

    Full Text Available Chagas disease is one of the main parasitic diseases found in Latin America and it is estimated that between six and seven million people are infected worldwide. Its etiologic agent, the protozoan Trypanosoma cruzi, is transmitted by triatomines, some of which from the genus Rhodnius. Twenty species are currently recognized in this genus, including some closely related species with low levels of morphological differentiation, such as Rhodnius montenegrensis and Rhodnius robustus. In order to investigate genetic differences between these two species, we generated large-scale RNA-sequencing data (consisting of four RNA-seq libraries from the heads and salivary glands of males of R. montenegrensis and R. robustus. Transcriptome assemblies produced for each species resulted in 64,952 contigs for R. montenegrensis and 70,894 contigs for R. robustus, with N50 of approximately 2,100 for both species. SNP calling based on the more complete R. robustus assembly revealed 3,055 fixed interspecific differences and 216 transcripts with high levels of divergence which contained only fixed differences between the two species. A gene ontology enrichment analysis revealed that these highly differentiated transcripts were enriched for eight GO terms related to AP-2 adaptor complex, as well as other interesting genes that could be involved in their differentiation. The results show that R. montenegrensis and R. robustus have a substantial quantity of fixed interspecific polymorphisms, which suggests a high degree of genetic divergence between the two species and likely corroborates the species status of R. montenegrensis.

  9. Triatominae (Hemiptera, Reduviidae) in the Pantanal region: association with Trypanosoma cruzi, different habitats and vertebrate hosts.

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    Santos, Filipe Martins; Jansen, Ana Maria; Mourão, Guilherme de Miranda; Jurberg, José; Nunes, Alessandro Pacheco; Herrera, Heitor Miraglia

    2015-01-01

    The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection. The fieldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at five selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads. In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher efficiency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests. Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruziin the Pantanal region.

  10. Triatominae as a model of morphological plasticity under ecological pressure

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    Dujardin JP

    1999-01-01

    Full Text Available The use of biochemical and genetic characters to explore species or population relationships has been applied to taxonomic questions since the 60s. In responding to the central question of the evolutionary history of Triatominae, i.e. their monophyletic or polyphyletic origin, two important questions arise (i to what extent is the morphologically-based classification valid for assessing phylogenetic relationships? and (ii what are the main mechanisms underlying speciation in Triatominae? Phenetic and genetic studies so far developed suggest that speciation in Triatominae may be a rapid process mainly driven by ecological factors.

  11. Efeito de extratos de plantas do Cerrado em Dipetalogaster maxima (Uhler (Hemiptera, Reduviidae Effect of Cerrado plant extracts on Dipetalogaster maxima (Uhler (Hemiptera, Reduviidae

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    André A. M. Coelho

    2009-01-01

    Full Text Available A transmissão da doença de Chagas ocorre, principalmente, por meio de fezes de hemípteros hematófagos (Triatominae, os quais ingerem o Trypanosoma cruzi ao se alimentarem do sangue de pessoas ou outros mamíferos infectados. Para o controle dos triatomíneos, os piretróides são os principais inseticidas utilizados. Entretanto, algumas populações de insetos demonstraram resistência a determinados piretróides, indicando a necessidade do desenvolvimento de novos inseticidas eficazes no controle desses vetores. Assim, foi avaliada a atividade inseticida de 83 extratos vegetais, pertencentes a 35 espécies diferentes, em ninfas do primeiro estádio de Dipetalogaster maxima (Uhler, 1894 (Hemiptera: Reduviidae, triatomíneo encontrado no México. Para o teste tópico, foram aplicados 50 ìg de cada extrato nos tergitos abdominais de dez ninfas, em duplicata. Como controles, foram utilizados insetos tratados com etanol, acetona ou sem nenhum tipo de tratamento. Os triatomíneos foram observados durante 28 dias. Nenhum extrato apresentou atividade inseticida significativa, entretanto, o extrato hexânico do fruto e o etanólico da casca do caule de Simarouba versicolor (Simaroubaceae inibiram a taxa de ecdise em D. maxima (40% e 25%, respectivamente. Sugere-se que estes extratos sejam quimicamente investigados e monitorados por ensaios biológicos a fim de determinar os componentes, para que estes possam ser utilizados como modelos moleculares ou como compostos biorracionais nos programas de controle de insetos.Chagas disease, also known as American Trypanosomiasis, is chiefly transmitted by faeces of haematophagous bugs (Triatominae that ingested Trypanosoma cruzi from blood of infected people or other mammals. Pyrethroids have been the main insecticides used against these insects. However, some populations of insects have shown significant levels of resistance to several pyrethroids, indicating the need of new insecticides for the control of

  12. Triatominae as a model of morphological plasticity under ecological pressure

    OpenAIRE

    Dujardin, Jean-Pierre; Panzera, P.; Schofield, C.J.

    1999-01-01

    The use of biochemical and genetic characters to explore species or population relationships has been applied to taxonomic questions since the 60s. In responding to the central question of the evolutionary history of #Triatominae$, i.e. their monophyletic or polyphyletic origin, two important questions arise (i) to what extent is the morphologically-based classification valid for assessing phylogenetic relationships ? and (ii) what are the main mechanisms underlying speciation in #Triatominae...

  13. Seasonality and Temperature-Dependent Flight Dispersal of Triatoma infestans (Hemiptera: Reduviidae) and Other Vectors of Chagas Disease in Western Argentina.

    Science.gov (United States)

    Di Iorio, Osvaldo; Gürtler, Ricardo E

    2017-09-01

    Flight dispersal of Triatominae is affected by climatic conditions and determines the spatiotemporal patterns of house invasion and transmission of Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae). We investigated the detailed time structure and temperature dependencies of flight occurrence of Triatoma infestans Klug (Hemiptera: Reduviidae) and other triatomine species in a rural village of western Argentina by taking advantage of the attraction of adult triatomines to artificial light sources. Most of the village's streetlight posts were systematically inspected for triatomines twice between sunset and midnight over 425 nights in the spring-summer seasons of 1999-2002, an unprecedented light-trap sampling effort for any triatomine species. In total, 288 adults were captured, including 122 Triatoma guasayana Wygodzinsky and Abalos, 89 T. infestans, 72 Triatoma eratyrusiformis Del Ponte, and 5 Triatoma garciabesi Carcavallo et al. Adult sex ratios were balanced in T. infestans and strongly male-biased in other species. Nearly all flight-dispersing triatomines were caught when temperatures at sunset were >20 °C (range, 16.6-31.7 °C), suggesting a putative threshold around 17-18 °C. Triatomine catches were rare on rainy days. Logistic regression analysis revealed that the proportion of nights in which at least an adult T. infestans was caught increased highly significantly with increasing temperature at sunset and was modified by collection month, with greater catches in early spring and no sex differential. This study confirms that spring represents a previously overlooked, important dispersal period of T. infestans, and shows large variations among and within Triatominae in their temporal patterns of flight occurrence, abundance, and sex ratio. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Triatominae survey (Hemiptera: Reduviidae: Triatominae) in the south-central region of the state of Bahia, Brazil between 2008 and 2013.

    Science.gov (United States)

    Mendonça, Vagner José; de Oliveira, Jader; Rimoldi, Aline; Filho, Júlio C R Ferreira; de Araújo, Renato Freitas; da Rosa, João Aristeu

    2015-05-01

    Triatomine surveillance in rural areas, artificial ecotypes, and natural ecotopes of the cities of Caturama, Ibipitanga, Macaúbas, and Seabra in the south-central region of the Brazilian state of Bahia was carried out between 2008 and 2013. Natural infection by Trypanosoma cruzi was evaluated in the specimens collected to monitor vectors of Chagas disease. A total of 1,357 specimens were collected, and four species were identified: Triatoma sordida (83%), Triatoma lenti (16.4%), Triatoma pseudomaculata (0.5%), and Panstrongylus geniculatus (0.1%). Triatoma sordida was found in four cities, only 0.7% in intradomiciliary environments. Triatoma lenti was found only in Macaúbas; 8.5% were found in intradomiciliary environments, 88.3% in peridomiciliary environments, and 3.1% in sylvatic environments. Natural infection by T. cruzi was 0.5% for T. sordida and 3.1% T. lenti. All of these cases were found in peridomiciliary environments of Macaúbas. As the results show, triatomines were found in intradomiciliary environments in three cities that were surveyed in the south-central region of the state of Bahia. Thus, an epidemiologic survey should be performed to avoid the risk of transmission to the population. © The American Society of Tropical Medicine and Hygiene.

  15. Ocorrência de Psammolestes coreodes Bergroth, 1911 (Hemiptera: Reduviidae: Triatominae no Estado de Mato Grosso do Sul Occurrence of Psammolestes coreodes Bergroth, 1911 (Hemiptera: Reduviidae: Triatominae, in the State of Mato Grosso do Sul

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    Paulo Silva de Almeida

    2009-10-01

    Full Text Available Neste trabalho, relata-se a ocorrência de Psammolestes coreodes Bergroth, 1911 pela primeira vez no Estado de Mato Grosso do Sul. Em 2006, um espécime foi capturado em um ambiente peridomiciliar do município de Miranda, incluindo o Estado de Mato Grosso do Sul, na distribuição geográfica dessa espécie.This paper describes the occurrence of Psammolestes coreodes Bergroth, 1911, for the first time in the State of Mato Grosso do Sul. In 2006, a specimen was caught in a peridomestic environment in the municipality of Miranda, thereby including Mato Grosso do Sul within the geographical distribution of this species.

  16. Estudos sobre a resistência ao jejum e aspectos nutricionais de Cavernicola lenti Barrett & Arias, 1985 (Hemiptera, Reduviidae, Triatominae Studies on the resistance to fasting and nutritional aspects of Cavernicola lenti Barret & Arias, 1985 (Hemiptera, Reduviida, Triatominae

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    Jane Margaret Costa

    1989-01-01

    Full Text Available In order to widen the present knowledge on the biology of this species, a study on the resistance to starvation was carried out among all nymphal stages and the adult stage (male and female. All evolutive stages were weighed on precision scale in three different nutritional situations: fed, non-fed and death registered after starvation. This procedure has allowed us to calculate the amount of blood taken in each stage and during the whole cycle, the average loss of weight during starvation and its relations with the initial weight. The insects were fed on mice and after eclosion or ecdisis they were isolated for observation of the starving period. Throuhout the whole experiment they were kept in a B. O. D./DOB incubator (28ºC and 90%R.U.. The resistance to starvation of the insects has grown from the first stage on (average of 15.5 days to the fifth stage (average of 75.64 days; on the adult stage, the resistance period was equal to the third stage with an average of 41.76 for the males and 44.82 for the females. The amount of ingested blood was greater at the fifth stage worth 34.14 mg, corresponding to 2,04 times its initial weight. The average weight loss during the starvation was greater at the adult stage (23.95 mg, corresponding to 61.52% of the total weight.

  17. Estudos sobre a resistência ao jejum e aspectos nutricionais de Triatoma lecticularia (Stal, 1859 (Hemiptera, Reduviidae, Triatominae Studies on the resistance to fasting and nutritional aspects of Triatoma lecticularia (Stal, 1859 (Hemiptera, Reduviidae, Triatominae

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    José Jurberg

    1989-09-01

    Full Text Available Foi feito um estudo sobre a resistência ao jejum em todas as fases evolutivas e pesagens em diferentes situações nutricionais de Triatoma lecticularia (alimentado; não alimentado; na morte após o jejum com temperatura e umidade registradas. Observou-se que os períodos de resistência das fases ninfais apresentaram médias (dias crescentes: 1º: 45,84; 2º: 61; 3º: 88,74; 4º: 123,47; 5º 162,30. Na fase adulta as médias foram aproximadas à do 3º estádio (para os machos 88,94 e para as fêmeas 83,66. O procedimento de pesagens permitiu registrar a quantidade de sangue ingerido, a perda de peso durante o jejum e o respectivo percentual em relação ao peso inicial. Esta espécie tem assinalada sua distribuição geográfica na região Neártica, onde tem sido encontrda infectada com Trypanosoma cruzi associada a Neotoma micropus Baird e Spermophilus variagatus (Erxeleben.The resistance to fasting of Triatoma lecticularia was studied in all phases of the life cycle and the insect weighed in different nutritional situations (fed, not fed, death after starvation. The temperature and humidity level were also recorded. The nymphal phases showed increasing resistance to fasting as demonstrated by the following averages (days 1st 45.84; 2nd 61; 3rd 88.74; 4th 123.44; 5th 162.30. Upon the adult phase, the averages were similar to those of the 3rd stage for the male insects 88.94 and for females 83.66. The weighing technique allowed for the measeurement of the quantity of blood ingested, the weight loss during the fast and the percentage weight lost as related to the initial weight. The species is found in the Neartic region where it has been found infected with Trypanosoma cruzi and is associated with the terrestial rodents Neotoma micropus Baird and Spermophilus variagatus (Erxelebem.

  18. Triatoma vandae sp. n. do complexo oliveirai encontrada no estado de Mato Grosso, Brasil (Hemiptera: Reduviidae: Triatominae Triatoma vandae sp.n. of the oliveirai complex from the State of Mato Grosso, Brazil (Hemiptera: Reduviidae: Triatominae

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    Rodolfo U Carcavallo

    2002-07-01

    Full Text Available There are several specific complexes belonging to the genus Triatoma Laporte, 1832, which are generally associated to specific geographic areas. Recent publications have linked the oliveirai complex to ecosystems of Mato Grosso, which are also present in other Brazilian states and even in other bordering countries as eastern Paraguay. The study of the abundant material collected during the last years allowed the description of several new species of the oliveirai complex: T. jurbergi Carcavallo, Galvão & Lent, 1998; T. baratai Carcavallo & Jurberg, 2000 and T. klugi Carcavallo, Jurberg, Lent & Galvão, 2001. Another new species belonging to the same complex is described here as T. vandae sp.n. It originates from the state of Mato Grosso, and has been reared in the insectary of the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Departamento de Entomologia, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro.

  19. Inter-specific and developmental differences on the array of antennal chemoreceptors in four species of triatominae (Hemiptera: Reduviidae

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    M Gracco

    2000-01-01

    Full Text Available The aim of the work was to investigate the pattern of chemoreceptor sensilla in adults and fifth stage nymphs of Rhodnius prolixus, R. neglectus, Triatoma infestans and T. sordida in order to study differences and similarities between genera and species. Three types of sensilla were analyzed by light microscopy: thin-walled trichoidea, thick-walled trichoidea and basiconica. The number of sensilla of each three types were counted. The length of the antennal segments were also used as a variable for the analysis. The statistical analysis showed that the number of these antennal chemoreceptors had significant differences between species and between adults and nymphs of each species. Discriminant analysis separates incompletely the fifth stage nymphs of the four species and showed similarity between them. Discriminant analysis performed with 12 variables of the antennae, allowed a complete separation of the adults of the four species.

  20. Influence of light conditions on adult mortality and egg-laying of Triatoma brasiliensis neiva, 1911 (Hemiptera: Reduviidae: Triatominae

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    Carlos Brisola Marcondes

    1992-12-01

    Full Text Available We compared, for Triatoma brasiliensis, the egg-laying process and the mortality of adults under conditions of almost permanent darkness and with normal laboratory luminosity. Mortality did not differ between groups. The egg-laying per vial and per female was significantly greater in the group of normal luminosity. We consider that it is not recommendable to keep the adults of this species under complete darkness. Other biological aspects should be analysed in relation to luminosity.

  1. Repellency of the Components of the Essential Oil, Citronella, to Triatoma rubida, Triatoma protracta, and Triatoma recurva (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    Zamora, D; Klotz, S A; Meister, E A; Schmidt, J O

    2015-07-01

    The kissing bugs--Triatoma rubida (Uhler), Triatoma protracta (Uhler), and Triatoma recurva (Stal)--are common hematophagous bugs in southeastern Arizona and responsible for severe allergic reactions in some individuals who are bitten. They also possess the potential to transmit the blood parasite, Trypanosoma cruzi. We previously found the essential oil, citronella, to be an excellent deterrent of feeding of T. rubida on a restrained mouse. In this work, we tested major components--alcohols, aldehydes, and monoterpenes--of citronella oil for repellency against the three common triatome species endemic in southern Arizona. The following citronella oil components--geraniol, citronellol, limonene, and citronellal--in different concentrations and combinations were tested. All components of citronella oil demonstrated some inhibition of feeding, ranging from very weak inhibition (limonene) to significant inhibition (geraniol and citronellol). A mixture of geraniol and citronellol was found to be repellant at concentrations of .165 and .165 vol%, respectively, for all three triatome species. Citronellal and limonene had no significant repellent activity. The repellent activity of citronella oil appears to be acting through direct contact with the bugs rather than diffusion of vapors. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. [Triatoma vandae sp.n. of the oliveirai complex from the State of Mato Grosso, Brazil (Hemiptera: Reduviidae: Triatominae)].

    Science.gov (United States)

    Carcavallo, Rodolfo U; Jurberg, José; Rocha, Dayse da Silva; Galvao, Cleber; Noireau, François; Lent, Herman

    2002-07-01

    There are several specific complexes belonging to the genus Triatoma Laporte, 1832, which are generally associated to specific geographic areas. Recent publications have linked the oliveirai complex to ecosystems of Mato Grosso, which are also present in other Brazilian states and even in other bordering countries as eastern Paraguay. The study of the abundant material collected during the last years allowed the description of several new species of the oliveirai complex: T. jurbergi Carcavallo, Galvão Lent, 1998; T. baratai Carcavallo Jurberg, 2000 and T. klugi Carcavallo, Jurberg, Lent Galvão, 2001. Another new species belonging to the same complex is described here as T. vandae sp.n. It originates from the state of Mato Grosso, and has been reared in the insectary of the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Departamento de Entomologia, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro.

  3. Molecular Evidence of Demographic Expansion of the Chagas Disease Vector Triatoma dimidiata (Hemiptera, Reduviidae, Triatominae) in Colombia

    Science.gov (United States)

    Gómez-Palacio, Andrés; Triana, Omar

    2014-01-01

    Background Triatoma dimidiata is one of the most significant vectors of Chagas disease in Central America and Colombia, and, as in most species, its pattern of genetic variation within and among populations is strongly affected by its phylogeographic history. A putative origin from Central America has been proposed for Colombian populations, and high genetic differentiation among three biographically different population groups has recently been evidenced. Analyses based on putatively neutral markers provide data from which past events, such as population expansions and colonization, can be inferred. We analyzed the genealogies of the nicotinamide adenine dinucleotide dehydrogenase 4 (ND4) and the cytochrome oxidase subunit 1-mitochondrial genes, as well as partial nuclear ITS-2 DNA sequences obtained across most of the eco-geographical range in Colombia, to assess the population structure and demographic factors that may explain the geographical distribution of T. dimidiata in this country. Results The population structure results support a significant association between genetic divergence and the eco-geographical location of population groups, suggesting that clear signals of demographic expansion can explain the geographical distribution of haplotypes of population groups. Additionally, empirical date estimation of the event suggests that the population's expansion can be placed after the emergence of the Panama Isthmus, and that it was possibly followed by a population fragmentation process, perhaps resulting from local adaptation accomplished by orographic factors such as geographical isolation. Conclusion Inferences about the historical population processes in Colombian T. dimidiata populations are generally in accordance with population expansions that may have been accomplished by two important biotic and orographic events such as the Great American Interchange and the uplift of the eastern range of the Andes mountains in central Colombia. PMID:24625572

  4. Triatominos (Reduviidae: Triatominae en un foco de enfermedad de Chagas en Talaigua Nuevo (Bolívar, Colombia.

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    Luis Alberto Corté

    2005-12-01

    Full Text Available Introducción. Se describen las características e importancia epidemiológica de los triatominos presentes en un foco de enfermedad de Chagas en el municipio de Talaigua Nuevo, departamento de Bolívar. Objetivo. Determinar y correlacionar características ecológicas de los triatominos presentes en un foco de Chagas en el municipio de Talaigua Nuevo, Bolívar. Materiales y métodos. La captura de los triatominos se realizó en 300 domicilios del casco urbano en los que se revisaron el intra y peridomicilio, así como ambientes extradomésticos (palmas de vino y cúmulos de madera y leña. Resultados. Se capturaron 103 triatominos pertenecientes a cuatro especies: Triatoma maculata, Eratyrus cuspidatus, Panstrongylus geniculatus y Rhodnius prolixus. T. maculata, fue la especie predominante (92,3%. El 93% de los triatominos fueron capturados en ambientes intradomiciliarios. Conclusión. Se reporta por primera vez en Bolívar la captura de individuos de T. maculata infectados naturalmente con Trypanosoma sp. Se amplía la distribución geográfica de P. geniculatus y R. prolixus. El análisis de correspondencias múltiples no encontró ninguna relación significativa entre las características físicas de las viviendas y la presencia de triatominos dentro de ellas.

  5. Comparison of biological fitness in crosses between subspecies of Meccus phyllosomus (Hemiptera: Reduviidae: Triatominae) in southern Mexico.

    Science.gov (United States)

    Martínez-Ibarra, José Alejandro; Nogueda-Torres, Benjamín; Salazar-Montaño, Luis Fernando; García-Lino, Juan Carlos; Arroyo-Reyes, Demver; Hernández-Navarro, Juan Ángel

    2017-02-01

    Understanding the biological parameters of some triatomine subspecies of Meccus phyllosomus (Burmeister) is a crucial first step in estimating the epidemiologic importance of this group. Biological parameters related to hatching, lifetime, number of blood meals to molt, percentage of females at the end of the cycle, number of laid eggs, and mortality for each instar of 3 M. phyllosomus subspecies [M. p. mazzottii (Usinger), M. p. pallidipennis (Stål), and M. p. phyllosomus] and their laboratory hybrids were evaluated and compared. No significant differences (P > 0.05) were found among the experimental hybrids (MaPa, MaPhy, PaPhy) and reciprocal cohorts. In 5 (hatching, number of blood meals to molt, accumulative mortality, percentage of females, and mean number of laid eggs) of the 6 studied parameters (with the exception of development time), the hybrid cohorts had better fitness results than the parental cohorts involved in each set of crosses. The increase in hybrid fitness found in our study could lead to an increase in the epidemiologic risks caused by transmission of Trypanosoma cruzi to humans. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  6. [Occurrence of Psammolestes coreodes Bergroth, 1911 (Hemiptera: Reduviidae: Triatominae), in the State of Mato Grosso do Sul].

    Science.gov (United States)

    Almeida, Paulo Silva de; Gonçalves, Guilmara Maria do Amaral; Minzão, Luiz Donizethe; Larson, Ramão Virgilio Genro; Cristaldo, Luis Carlos Medina; Ceretti Júnior, Walter; Obara, Marcos Takashi; Barata, José Maria Soares

    2009-01-01

    This paper describes the occurrence of Psammolestes coreodes Bergroth, 1911, for the first time in the State of Mato Grosso do Sul. In 2006, a specimen was caught in a peridomestic environment in the municipality of Miranda, thereby including Mato Grosso do Sul within the geographical distribution of this species.

  7. New record and cytogenetic analysis of Psammolestes tertius Lent & Jurberg, 1965 (Hemiptera, Reduviidae, Triatominae) from Bahia State, Brazil.

    Science.gov (United States)

    Oliveira, J; Alevi, K C C; Fonseca, E O L; Souza, O M F; Santos, C G S; Azeredo-Oliveira, M T V; da Rosa, J A

    2016-06-20

    This paper reports on the first occurrence of Psammolestes tertius in the Chapada Diamantina region, located in the city of Seabra, Bahia State, in northeastern Brazil. Following an active search, 24 P. tertius specimens were collected from Phacellodomus rufifrons (rufous-fronted thornbird) nests. The insects did not present any symptoms of infection by Trypanosoma cruzi. P. tertius males were cytogenetically analyzed, and the results were compared with those of other specimens from the Brazilian State of Ceará. Triatomines from both locations presented the same cytogenetic characteristics: 22 chromosomes, little variation in the size of the autosomes, Y chromosomes that were larger than the X chromosomes, a chromocenter formed only by the sex chromosomes during prophase, and autosomes lacking constitutive heterochromatin. However, it is important to note that this species shows intraspecific chromosomal variation. In light of the results obtained, it is recommended that more studies be performed to characterize P. tertius. These studies will be particularly helpful in understanding this species in ecological, biological, biogeographical, and phylogenetic terms.

  8. Distribución actual e importancia epidemiológica de las especies de triatominos (Reduviidae: Triatominae en Colombia

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    Jorge A. Molina

    2000-12-01

    Full Text Available Se presenta la distribución geográfica y la importancia epidemiológica en la transmisión de la enfermedad de Chagas de las 23 especies de triatominos presentes en Colombia, tomando como base los registros bibliográficos existentes en el pais y las colecciones de referencia del Laboratorio de Entomologia del Instituto Nacional de Salud y del Centro de Investigaciones en Microbiologia y Parasitologia Tropical de la Universidad de los Andes; además, se realiza un análisis de las condiciones ecológicas en las cuales han sido registrados triatominos en los paises con fronteras con Colombia para poder establecer la presencia de posibles especies que aún no se han registrado en nuestro pais. De esta manera. existe la posibilidad de tener en Colombia especies con hábitos silvestres como: Alberprosenia malheiroi. Belminus laportei y Cavernicola lenti, preentes todas ellas en los departamentos amazónicos; Triatoma nigromaculata en la Cordillera Oriental y con hábitos intradomiciliarios; Panstrongylus chinai con posibilidad de encontrarse en hábitats selváticos o en las viviendas de los colonos de la Amazonia debido a su atracción por la luz y Alberprosenia goyovargasien hábitats silvestres de la frontera con Venezuela. Se resalta la importancia de la vigilancia entomológica a nivel nacional como estrategia para reforzar los estudios de triatominos silvestres en Colombia.

  9. Influence of the blood meal source on the biology of Meccus picturatus Usinger 1939 (Hemiptera: Reduviidae: Triatominae under laboratory conditions

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    Martínez-Ibarra José Alejandro

    2003-01-01

    Full Text Available Aspects related to hatching, time-lapse between presenting the blood meal and beginning of feeding, feeding time, postfeed defecation delay,life time, mortality and fecundity for each stage of Meccus picturatus, life-cycle were evaluated and compared in two cohorts of M. picturatus fed on hens or rabbits. The hatching rate observed for each of the two studied groups of eggs was 78.1% (n = 2298 on the group fed on hens and 82.1% (n = 2704 on that fed on rabbits, and the average time of hatching was 20 days. Mean time-lapse for beginning feeding was under 3 min in nymphal stages and postfeed defecation delay was under 10 min in all stages, in both cohorts. Mean feeding time was significantly (P 0.05 differences were recorded among the average times from NI to adult in the cohort fed on hens (196.8 ± 15.8 days and the average time in the cohort fed on rabbits (189.5 ± 22.9. The average span in days for each stage fed on hens was not significantly different to the average span for each stage fed on rabbits. The number of blood meals at each nymphal stage varied from 1 to 6 in both cohorts. The mortality rates were higher on fifth nymphal stage, in both cohorts. No significant (P > 0.05 differences were recorded on mortality rates on most nymphal stages of both cohorts. The average number of eggs laid per female from the cohort fed on hens in a 9-month period was 791.1, whereas the average number of eggs in the cohort fed on rabbits was 928.3.

  10. Biology of three species of the Meccus phyllosomus complex (Hemiptera: Reduviidae: Triatominae fed on blood of hens and rabbits

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    José Alejandro Martínez-Ibarra

    2006-11-01

    Full Text Available Aspects related to hatching, life time, number of blood meals to molt, mortality, feeding time and postfeed defecation delay for each instar of Meccus phyllosomus, M. mazzottii, and M. bassolsae, life-cycle were evaluated and compared in two cohorts of each of those three species, fed on hens or rabbits. No significant (p > 0.05 differences were recorded among cohorts fed on hens respect to cohorts fed on rabbits in M. phyllosomus and M. mazzottii and the average time of hatching was 21.5 days for cohorts fed on hens and 22.5 for cohorts fed on rabbits. Average egg-to-adult development times were no significant (p > 0.05 different between both cohorts of M. phyllosomus and M. mazzotti, independent of the blood meal source. The average span in days for each instar fed on hens was not significantly different to the average span for each instar fed on rabbits, when comparisons were made by species. The number of blood meals at each nymphal instar varied from 1 to 6 in both cohorts of each species. The mortality rates were higher on older nymphs, in both cohorts of M. phyllosomus and M. bassolsae, whereas they were higher on first instar nymphs on M. mazzottii. Mean feeding time was no significant (p > 0.05 different in triatomines fed on hens or fed on rabbits, when each species were compared separately. A similar number of nymphs of each cohort, completed the cycle. Defecation delay was no significant (p > 0.05 different when cohorts fed on hens and fed on rabbits were compared by species. Most of the studied parameters showed no significant (p > 0.05 differences among those cohorts fed on hens and for fed on rabbits, which could mean a high degree of association of those species with birds as much as mammals, under wild conditions, increasing their capacity to colonize human dwellings.

  11. Eye colour as a genetic marker for fertility and fecundity of Triatoma infestans (Klug, 1834 Hemiptera, Reduviidae, Triatominae

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    Pires Herton Helder Rocha

    2002-01-01

    Full Text Available Eye colour of Triatoma infestans is controlled at a single autosomal locus, with black-eye as the dominant gene and red-eye as the recessive. Inheritance of these characters follows a classical Mendelian system, enabling eye colour to be used as a marker for studies of mating frequency. We found no significant differences in oviposition rates and egg hatching rates irrespective of parental phenotypes. Different mating schedules between red-eye and black-eye parents showed that eye colour did not affect mating competence. Females mated with a single male or with different males together or in succession produced similar numbers of fertile eggs, with the eye colour of the offspring reflecting exposure to the different males. We conclude that although a single mating can provide sufficient sperm for the whole reproductive life of the female, multiple matings can result in balanced assortative sperm usage from the spermatheca.

  12. Morphological Studies on the Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae, Triatominae Genital Structures and Eggs of Different Chromatic Forms

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    Jane Costa

    1997-07-01

    Full Text Available Triatoma brasiliensis is considered one of the most important Chagas disease vectors being a widespread species in semiarid areas of northeastern Brazil. The species displays distinct chromatic patterns of the cuticle in different localities. Four populations were analyzed in this study: 1-Caicó, Rio Grande do Norte, it will be called the brasiliensis population; 2-Espinosa, Minas Gerais, the melanica population; 3-Petrolina, Pernambuco, the macromelasoma population, and 4-Juazeiro, Bahia, the darker one in overall cuticle coloration, the Juazeiro population. In order to differentiate the four populations of T. brasiliensis, a comparative morphological analysis of external genital structures and of eggs were carried out. The analysis of the male genital structures evidenced minor individual structural variations that did not correlate with chromatic differences or the geographical origins, emphasizing the importance of examining sufficiently large and representative samples before using minor genital variations for taxonomic diagnosis. By scanning electron microscopy of the egg exochorion, each chromatic population presented a distinct ornamentation pattern. The melanica population differed mainly from the other populations studied since it had about 40.6%, 69.6% and 76.6% more perforations, on each cell exochorion, than the brasiliensis, the Juazeiro and the macromelasoma populations respectively. In the melanica population the perforation layout is also peculiar, with densely distributed perforations over all the egg surface. Morphometric measures of the eggs showed statistically significant differences: the macromelasoma population presented the longest length (2.43 mm while the shortest was recorded in the brasiliensis population (2.29 mm.

  13. First Report of Widespread Wild Populations of Triatoma infestans (Reduviidae, Triatominae) in the Valleys of La Paz, Bolivia

    Science.gov (United States)

    Buitrago, Rosio; Waleckx, Etienne; Bosseno, Marie-France; Zoveda, Faustine; Vidaurre, Pablo; Salas, Renata; Mamani, Elio; Noireau, François; Brenière, Simone Frédérique

    2010-01-01

    Wild populations of Triatoma infestans, the main vector of Chagas disease in the Southern Cone countries, may be involved in reinfestation of human dwellings, limiting the success of vector-control campaigns in Bolivia. Knowledge of the distribution of these populations remains incomplete. We report here the detection of T. infestans wild populations in large areas in the department of La Paz, Bolivia. Among 18 sylvatic areas investigated, 17 were positive with T. infestans specimens. The infection rate of captured T. infestans with Trypanosoma cruzi was 85.7% in adult specimens. These results expand the geographical distribution of wild populations of T. infestans; it may be distributed throughout the Inter-Andean Dry Forest eco-region of Bolivia. The current information allows us to propose the hypothesis that a sylvatic origin of the reinfestation is located in the valleys of La Paz. PMID:20348501

  14. The modern morphometric approach to identify eggs of Triatominae.

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    Santillán-Guayasamín, Soledad; Villacís, Anita G; Grijalva, Mario J; Dujardin, Jean-Pierre

    2017-01-31

    Egg morphometrics in the Triatominae has proved to be informative for distinguishing tribes or genera, and has been based generally on traditional morphometrics. However, more resolution is required, allowing species or even population recognition, because the presence of eggs in the domicile could be related to the species ability to colonize human dwellings, suggesting its importance as a vector. We explored the resolution of modern morphometric methods to distinguish not only tribes and genera, but also species or geographic populations in some important Triatominae. Four species were considered, representing two tribes and three genera: Panstrongylus chinai and P. howardi, Triatoma carrioni and Rhodnius ecuadoriensis. Within R. ecuadoriensis, two geographical populations of Ecuador were compared. For these comparisons, we selected the most suitable day of egg development, as well as the possible best position of the egg for data capture. The shape of the eggs in the Triatominae does not offer true anatomical landmarks as the ones used in landmark-based morphometrics, except for the egg cap, especially in eggs with an evident "neck", such as those of the Rhodniini. To capture the operculum shape variation, we used the landmark- and semilandmark-based method. The results obtained from the metric properties of the operculum were compared with the ones provided by the simple contour of the whole egg, as analyzed by the Elliptic Fourier Analysis. Clear differences could be disclosed between the genera, between the species - among which two very close species (P. chinai and P. howardi), as well as between two allopatric, conspecific populations. The whole egg contour (including the operculum) produced reclassification scores much more satisfactory than the ones obtained using the operculum only. We propose the outline-based approach as the most convenient characterization tool to identify unknown eggs at the species or population levels.

  15. Classification, evolution, and species groups within the Triatominae.

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    Schofield, C J; Galvão, Cleber

    2009-01-01

    Classification of the Triatominae has become a complex balance between traditional approaches and a wide variety of evolutionary interpretations. On the one hand is the need for a stable classification of practical use for those involved in vector surveillance and control. On the other is the desire to adequately reflect evolutionary theory derived from a range of molecular, cytogenetic and morphometric comparisons, with additional complications raised by current interpretations of the subfamily as a recently derived polyphyletic assemblage. Here we review key aspects of triatomine systematics and evolution, to derive a pragmatic classification that seeks to build on traditional morphological concepts within the context of current evolutionary theories.

  16. Distribución de los triatominae en Colombia

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    Hernando Ucrós

    1960-10-01

    Full Text Available This report complies the data published in Colombia literature on the geographic distribution of triatominae. It alos includes the geographic distribution of the reported cases of chagas disease of human infestations by trypanosoma rangeli ariarii and other undetermined trypanosomas. It is emphasized that the triatominae are distributed in localities whose altitude varies between 0 and 2133 meters above sea level and where the median annual temperature varies from 18 to 29 centigrade. The national literature registers at present only 35 to 40 human cases of chagas disease. Since 90 per cent of Colombian territory has an altitude of less than 20.000 meters above sea level there is a possibility that not only the distribution of traitominae but also human trypanosomiasis are more widely spread than is at present known. Tje existence of rhodnius prolixus is also reported in the following localities: Bucaramanga and Piedecuesta, Santander del Sur department, and Chinácota, San Cayetano, Santiago, Tibú, Tres Bocas, Catama and Villa del Rosario, Santander del Norte department.

  17. Nucleolar persistence during spermatogenesis of the genus Rhodnius (Hemiptera, Triatominae).

    Science.gov (United States)

    Alevi, Kaio Cesar Chaboli; da Costa Castro, Nayara Fernanda; Lima, Anna Claudia Campaner; Ravazi, Amanda; Morielle-Souza, Alessandra; de Oliveira, Jader; da Rosa, João Aristeu; de Azeredo Oliveira, Maria Tercília Vilela

    2014-08-01

    The Triatominae subfamily is comprised of 18 genera and six tribes. The tribe Rhodniini is comprised of two genera (Rhodnius and Psammolestes). Nucleolar persistence is defined by the presence of the nucleolus or nucleolar corpuscles during the meiotic metaphase. To date, this phenomenon has been described for 13 species of triatomine that are included in the genera Triatoma, Rhodnius, and Panstrongylus. Thus, because the phenomenon of nucleolar persistence has been described in only two species of the genus Rhodnius, we have analyzed the nucleolar behavior during spermatogenesis of eight species of the genus Rhodnius (R. colombiensis, R. montenegrensis, R. nasutus, R. neglectus, R. neivai, R. pictipes, R. prolixus, and R. robustus), with a focus on nucleolar persistence. By means of cytogenetic analysis with silver ions, nucleolar behavior during spermatogenesis is described in the eight species of Rhodnius analyzed. In all of them nucleolar behavior was similar and the phenomenon of nucleolar persistence was often observed. Therefore, we confirm nucleolar persistence as a peculiarity of the genus Rhodnius. However, it is emphasized that new cytogenetic analysis should be performed in the Triatominae subfamily, more specifically among the 15 genera that do not exhibit the nucleolar behavior described, in order to assess whether this phenomenon is truly a synapomorphy of these hematophagous insects. © 2014 International Federation for Cell Biology.

  18. Diploid chromosome set of kissing bug Triatoma baratai (Hemiptera, Triatominae).

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    Alevi, K C C; Reis, Y V; Borgueti, A O; Mendonça, V J; Rosa, J A; Azeredo-Oliveira, M T V

    2015-02-06

    Triatomines are insects that are taxonomically included in the Hemiptera order and Triatominae subfamily. Based on phenotypic similarity, capacity hybridization, and genetic and ecological aspects, the triatomine species can be grouped into specific complexes and subcomplexes. However, these groupings have not been confirmed. Cytogenetic analyses are important cytotaxonomic tools for improving the taxonomic knowledge of triatomines. Thus, we examined the karyotype of Triatoma baratai and compared the results with those of other species in the Matogrossensis subcomplex in order increase the understanding of vector potential. We also examined the cytotaxonomic classification of this insect. Triatoma baratai, similarly to other species that currently compose the Matogrossensis subcomplex, contains 22 chromosomes (20A + XY). Here, we describe the diploid chromosome set of T. baratai. We confirmed their current classification in the Matogrossensis subcomplex and demonstrated that the species in this subcomplex present karyotype homogeneity.

  19. Triatominae in furnariid nests of the Argentine Gran Chaco.

    Science.gov (United States)

    Marti, G A; Echeverria, M G; Waleckx, E; Susevich, M L; Balsalobre, A; Gorla, D E

    2014-06-01

    Triatomines (Hemiptera, Reduviidae) are bloodsucking insects involved in the transmission of Trypanosoma cruzi, the causative agent of Chagas disease, an important public health problem in Latin America. The triatomine species found in sylvatic habitats generally play a limited epidemiological role compared to domestic species, but they may act as a reinfestation source of dwellings after insecticide spraying and have to be carefully considered in control strategies of Chagas disease transmission. The objectives of this work were to carry out a survey of the sylvatic triatomine species colonizing Furnariidae nests in a typical area of the Chaco region of Argentina during the winter and to study the parasites and natural enemies associated with the collected triatomines. Sixty-three triatomine specimens were collected from Furnariidae nests (Coryphistera alaudina and Phacellodomus sibilatrix) randomly selected within the study area. Fifty-four were identified as Psammolestes coreodes, seven as Triatoma platensis, and two as Triatoma infestans. Specimens of T. infestans and T. platensis were found in one nest. The first finding of instar nymphs of T. infestans x T. platensis in a sylvatic habitat is reported. For the first time, sylvatic collected specimens of T. platensis were found infected by T. cruzi. Triatoma virus was found in one Ps. coreodes specimen. © 2014 The Society for Vector Ecology.

  20. Can body traits, other than wings, reflect the flight ability of Triatominae bugs?

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    María Laura Hernández

    2015-12-01

    Full Text Available Abstract: INTRODUCTION : Insects of the subfamily Triatominae are vectors of Trypanosoma cruzi , the Chagas disease parasite, and their flying behavior has epidemiological importance. The flying capacity is strikingly different across and within Triatominae species, as well as between sexes or individuals. Many Triatoma infestans individuals have wings but no flying muscles. In other Triatominae species, no clear relationships were found between wing length and flying behavior. If wing presence or size is not reflective of the flying behavior, which other parts of the body could be considered as reliable markers of this important function? METHODS : The genus Mepraia has exceptional characteristics with invariably wingless females and wingless or winged males. We calculated the porous surface exposed to odorant molecules to estimate the olfactory capacity of Mepraia spinolai . The head shape and thorax size were estimated using the geometric morphometric approach and traditional morphometric techniques, respectively. RESULTS : Alary polymorphism in M. spinolai was significantly associated with consistent modification of the thorax size, head shape, and notable change in the estimated olfactory capacity. The macropterous individuals had a larger olfactory surface and thorax size and significantly different head shape compared to those of the micropterous individuals. CONCLUSIONS: We concluded that these structural changes could be associated with the flying potential of Triatominae. Thus, morphological attributes not found on wings could help determine the likely flying potential of the bugs.

  1. Can body traits, other than wings, reflect the flight ability of Triatominae bugs?

    Science.gov (United States)

    Hernández, María Laura; Dujardin, Jean Pierre; Gorla, David Eladio; Catalá, Silvia Susana

    2015-01-01

    Insects of the subfamily Triatominae are vectors of Trypanosoma cruzi , the Chagas disease parasite, and their flying behavior has epidemiological importance. The flying capacity is strikingly different across and within Triatominae species, as well as between sexes or individuals. Many Triatoma infestans individuals have wings but no flying muscles. In other Triatominae species, no clear relationships were found between wing length and flying behavior. If wing presence or size is not reflective of the flying behavior, which other parts of the body could be considered as reliable markers of this important function? The genus Mepraia has exceptional characteristics with invariably wingless females and wingless or winged males. We calculated the porous surface exposed to odorant molecules to estimate the olfactory capacity of Mepraia spinolai . The head shape and thorax size were estimated using the geometric morphometric approach and traditional morphometric techniques, respectively. Alary polymorphism in M. spinolai was significantly associated with consistent modification of the thorax size, head shape, and notable change in the estimated olfactory capacity. The macropterous individuals had a larger olfactory surface and thorax size and significantly different head shape compared to those of the micropterous individuals. We concluded that these structural changes could be associated with the flying potential of Triatominae. Thus, morphological attributes not found on wings could help determine the likely flying potential of the bugs.

  2. Cladistics and biogeography of the assassin bug genus Rasahus Amyot & Serville (Heteroptera: Reduviidae: Peiratinae)

    NARCIS (Netherlands)

    Morrone, J.J.; Coscarón, M. del C.

    1998-01-01

    The assassin bug genus Rasahus Amyot & Serville (Heteroptera: Reduviidae: Peiratinae) comprises 26 Neotropical species. A cladistic analysis of the genus was carried out using 63 characters from external morphology, body vestiture, and male and female genitalia, with the species considered as

  3. Epidaus wangi (Hemiptera: Heteroptera: Reduviidae), a new assassin bug from Tibet, China.

    Science.gov (United States)

    Chen, Zhuo; Zhu, Guangxiang; Wang, Jianyun; Cai, Wanzhi

    2016-08-18

    Epidaus wangi Chen, Zhu, Wang & Cai, sp. nov. (Hemiptera: Heteroptera: Reduviidae: Harpactorinae) from Tibet, China, is described and illustrated based on male and female specimens. The new species is morphologically similar to E. tuberosus Yang, 1940. The new species represents the first record of Epidaus species from Tibet.

  4. Triatoma rubrovaria (Blanchard, 1843 (Hemiptera, Reduviidae, Triatominae II: trophic resources and ecological observations of five populations collected in the State of Rio Grande do Sul, Brazil

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    Almeida Carlos Eduardo

    2002-01-01

    Full Text Available Triatoma rubrovaria has become the most frequently captured triatomine species after the control of T. infestans in the State of Rio Grande do Sul (RS, Brazil. Isoenzymatic and chromatic studies indicate the existence of, at least, two distinct phenotypic patterns of T. rubrovaria in RS. The geographic variation noted through molecular tools may also result in distinct profiles of vectorial potentiality. In order to enhance our understanding of the bionomic knowledge of T. rubrovaria separate batches of the species were collected from different municipalities of RS distant from 72 to 332 km: Santana do Livramento (natural ecotope, Santana do Livramento (artificial ecotope, Santiago (natural ecotope, Canguçu (peridomicile and Encruzilhada do Sul (natural ecotope. A total of 285 specimens were collected, 85 specimens kept sufficient fecal material in their guts for the precipitin analysis. The results indicated the food eclecticism for this species and the anti-rodent serum showed the highest positivity in most localities. From the total of analyzed samples, only 1.3% of unique positivity for human blood was registered, all of them for Santiago population. This reactivity to human blood may be associated to pastures activities in the field.

  5. Biology of Triatominae (Reduviidae Hemiptera from North of Formosa County (Goiás-Brazil I. Length of life cycle of Triatoma sordida (Stal. 1859

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    Dalva A. Mello

    1976-12-01

    Full Text Available In the present paper the life cycle of Triatoma sordida was studied. The mean length from egg to adult was 213 days. The mean length in days from each stage was: 24.3 (± 1.30 for the first. 32.8 (± 1.45 (2nd, 36.1 (± 1.50 (3rd, 44.6 (± 1.85 (4th and 52.0 (± 1.92 (5th. The mean egg incubation períod was 23.2 (± 1.40. Overall mortality was 18.8% and egg viability was 82.5%.Foi estudado no presente trabalho o ciclo biológico do Triatoma sordida A média da duração do ciclo de ovo a adulto foi 213 dias. A média de duração em dias para cada estágio foi 24,3 (± 1,30 para o primeiro, 32,8 (± 1,45 para o segundo, 36,1 (± 1,50 para o terceiro, 44,6 (± 1,85 para o quarto e 52,0 (± 1,92 para o quinto. A média do período de incubação dos ovos foi 23,2 (± 1,40. A mortalidade em todos ps estágios foi 18,8% e a viabilidade dos ovos foi 82,5%.

  6. Revalidation and redescription of Triatoma brasiliensis macromelasoma Galvão, 1956 and an identification key for the Triatoma brasiliensis complex (Hemiptera: Reduviidae: Triatominae).

    Science.gov (United States)

    Costa, Jane; Correia, Nathália Cordeiro; Neiva, Vanessa Lima; Gonçalves, Teresa Cristina Monte; Felix, Márcio

    2013-09-01

    Triatoma brasiliensis macromelasoma is revalidated based on the results of previous multidisciplinary studies on the Triatoma brasiliensis complex, consisting of crossing experiments and morphological, biological, ecological and molecular analyses. These taxonomic tools showed the closest relationship between T. b. macromelasoma and Triatoma brasiliensis brasiliensis. T. b. macromelasoma is redescribed based on specimens collected in the type locality and specimens from a F1 colony. The complex now comprises T. b. brasiliensis, T. b. macromelasoma, Triatoma melanica, Triatoma juazeirensis and Triatoma sherlocki. An identification key for all members of the complex is presented. This detailed comparative study of the morphological features of T. b. macromelasoma and the remaining members of the complex corroborates results from multidisciplinary analyses, suggesting that the subspecific status is applicable. This subspecies can be distinguished by the following combination of features: a pronotum with 1+1 narrow brownish-yellow stripes on the submedian carinae, not attaining its apex, hemelytra with membrane cells darkened on the central portion and legs with an incomplete brownish-yellow ring on the apical half of the femora. Because the T. brasiliensis complex is of distinct epidemiological importance throughout its geographic distribution, a precise identification of its five members is important for monitoring and controlling actions against Chagas disease transmission.

  7. Ecological niche and geographic distribution of the Chagas disease vector, Triatoma dimidiata (Reduviidae: Triatominae): Evidence for niche differentiation among cryptic species.

    Science.gov (United States)

    Gómez-Palacio, Andrés; Arboleda, Sair; Dumonteil, Eric; Townsend Peterson, A

    2015-12-01

    The principal vector of Chagas disease in Central America, Triatoma dimidiata, shows considerable diversity of habitat, phenotype, and genotype across its geographic range (central Mexico to southern Ecuador), suggesting that it constitutes a complex of cryptic species. However, no consistent picture of the magnitude of ecological differentiation among populations of this complex has yet been developed. To assess ecological variation across the complex, we broadened the geographic coverage of phylogeographic data and analyses for the complex into Colombia and Mexico, with additional nuclear (ITS-2) and mitochondrial (ND4) DNA sequences. This information allowed us to describe distributions of previously documented clades in greater detail: Group I, from central Guatemala south to Ecuador; Group II, across Mexico south through the Yucatán Peninsula to Belize and northern Guatemala; and Group III, in northern Guatemala, Belize, and the Yucatán Peninsula. Using ecological niche modeling, we assessed ecological niche differentiation among the groups using four hypotheses of accessible areas (M) across the distribution of the complex. Results indicated clear niche divergence of Group I from Group II: the speciation process thus appears to have involved genetic and ecological changes, suggesting divergence in populations in response to environmental conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Conducta alimentaria de poblaciones de triatoma dimidiata (hemiptera: reduviidae: triatominae) en una zona endémica y sus implicaciones epidemiológicas

    OpenAIRE

    Farfán-García, Ana E.; Angulo-Silva, Víctor M.

    2012-01-01

    Objetivo Determinar la conducta alimentaria de Triatoma dimidiata en hábitats domiciliarios y extradomiciliarios en una zona endémica de Santander, Colombia. Materiales y métodos Mediante la técnica de ELISA, se procesaron 367 contenidos intestinales de insectos capturados en zonas rurales de los municipios de Capitanejo y Macaravita. Estos fueron procesados por medio de la técnica de ELISA, con 12 antisueros policlonales anti-especie animal específicos. Los hospederos de T. dimidiata fueron ...

  9. [Spatio-temporal analysis of the biophysical and ecological conditions of Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae) in the northeast region of Colombia].

    Science.gov (United States)

    Badel-Mogollón, Jaime; Rodríguez-Figueroa, Laura; Parra-Henao, Gabriel

    2017-03-29

    Due to the lack of information regarding biophysical and spatio-temporal conditions (hydrometheorologic and vegetal coverage density) in areas with Triatoma dimidiata in the Colombian departments of Santander and Boyacá, there is a need to elucidate the association patterns of these variables to determine the distribution and control of this species. To make a spatio-temporal analysis of biophysical variables related to the distribution of T. dimidiate observed in the northeast region of Colombia. We used the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) data bases registering vector presence and hydrometheorologic data. We studied the variables of environmental temperature, relative humidity, rainfall and vegetal coverage density at regional and local levels, and we conducted spatial geostatistic, descriptive statistical and Fourier temporal series analyses. Temperatures two meters above the ground and on covered surface ranged from 14,5°C to 18,8°C in the areas with the higher density of T. dimidiata. The environmental temperature fluctuated between 30 and 32°C. Vegetal coverage density and rainfall showed patterns of annual and biannual peaks. Relative humidity values fluctuated from 66,8 to 85,1%. Surface temperature and soil coverage were the variables that better explained the life cycle of T. dimidiata in the area. High relative humidity promoted the seek of shelters and an increase of the geographic distribution in the annual and biannual peaks of regional rainfall. The ecologic and anthropic conditions suggest that T. dimidiata is a highly resilient species.

  10. Spatio-temporal analysis of the biophysical and ecological conditions of Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae in the northeast region of Colombia

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    Jaime Badel-Mogollón

    2017-03-01

    Conclusions: Surface temperature and soil coverage were the variables that better explained the life cycle of T. dimidiata in the area. High relative humidity promoted the seek of shelters and an increase of the geographic distribution in the annual and biannual peaks of regional rainfall. The ecologic and anthropic conditions suggest that T. dimidiata is a highly resilient species.

  11. Species of the subfamily Triatominae Jeannel, 1919 (Hemiptera: Reduviidae present in the Collection of Chagas Disease Vectors (FIOCRUZ-COLVEC, State of Minas Gerais

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    Rita de Cássia Moreira de Souza

    2014-12-01

    Full Text Available Introduction Biological collections are depositories of information on different species and contribute to the knowledge, protection, conservation and maintenance of biodiversity. Methods A list of triatomine species currently included in the Collection of Chagas Disease Vectors (FIOCRUZ-COLVEC was prepared from the database made available by the Reference Center on Environmental Information. Results COLVEC curatorship houses 4,778 specimens of triatomines, of which 811 come from other American countries (Argentina, Bolivia, Colombia, Costa Rica, the United States of America, Guatemala, Mexico, Peru, Uruguay and Venezuela and 3,967 are autochthonous from Brazil. Altogether, 56 species of Chagas disease vectors are represented in the COLVEC: two species of the Tribe Cavernicolini Usinger, 1944; fifteen species of the tribe Rhodniini Pinto, 1926, of which 12 are of the genus Rhodnius and 3 are of the genus Psamolestes; and 39 species of the tribe Triatomini Jeannel, 1919, represented by the genus Dipetalogaster, two species of the genus Eratyrus, two of the genus Meccus, seven of the genus Panstrongylus and 27 of the genus Triatoma. Conclusions This list provides important data on the diversity of triatomines currently included in COLVEC, including the expanded area of Panstrongylus lutzi occurrence in the municipalities Pirapora and Januária, State of Minas Gerais. The maintenance and expansion of the collection ensures the preservation of biodiversity and further studies.

  12. Resistencia a lambdacihalotrina y fenitrotión en una población de campo de Panstrongylus geniculatus (Hemiptera: Reduviidae: Triatominae

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    Flor A. Torres P

    2013-12-01

    Full Text Available Introducción: Panstrongylus geniculatus es un triatomino silvestre, vector del Trypanosoma cruzi, intruso en domicilios humanos. Determinar la susceptibilidad a insecticidas de uso común en esta especie es indispensable para detectar prematuramente cepas resistentes. Objetivo: Este estudio se propuso analizar la susceptibilidad a lambdacihalotrina y fenitrotión en dos cepas (laboratorio y campo de P. geniculatus. Metodología: se estableció la susceptibilidad a lambdacihalotrina y fenitrotión por aplicación tópica, en la cepa de laboratorio-Molagavita 2003 y en la población de campo-Chorreras 2012 en ninfas del primer estadio de P. geniculatus. Se calcularon valores de dosis letal 50 y dosis letal 99 (DL50 y la DL99 para cada insecticida. También se determinaron valores de grado de resistencia (GR para cada insecticida: DL50 población de campo/DL50 cepa de laboratorio. Resultados: Las DL50 y DL99 en la población de campo y la cepa de laboratorio (en ng/i, fueron: 1,194; 5,764 y 0,024; 0,131 para lambdacihalotrina y 1,476; 7,354 y 0,482; 5,471 para fenitrotión, respectivamente. Los grados de resistencia fueron: GR= 48,9 para lambdacihalotrina y GR= 3,06 para fenitrotión. Conclusiones: La población de campo mostró resistencia a lambdacihalotrina y fenitrotión, probablemente como consecuencia del uso de agroquímicos en la zona. Implementar medidas para la detección temprana de resistencia en triatominos es importante en el diseño de programas de control vectorial.

  13. Cría masiva y uso de ninfas de Rhodnius pallescens, Barber, 1932 (Hemiptera, Reduviidae, Triatominae para ensayos biológicoso

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    Mónica Flórez M

    2015-04-01

    Full Text Available Introducción: Rhodnius pallescens es una especie silvestre que hace intrusión a las viviendas en zonas en las cuales se han presentado brotes de Chagas agudo en Colombia; y para el estudio de sus características biológicas y el monitoreo de la susceptibilidad o resistencia de poblaciones de campo a insecticidas, se requiere del uso de una gran cantidad de insectos mantenidos en el laboratorio. Objetivo: Establecer condiciones de cría de ninfas de R. pallescens que permitan su mejor aprovechamiento en ensayos biológicos. Metodología: Se utilizó una cepa de laboratorio de R. pallescens proveniente de San Martin (Cesar, Colombia y se realizaron bioensayos para: estimar el tiempo de alimentación, establecer condiciones de cría, estimar tiempos de desarrollo ninfal y comparar la fecundidad usando dos fuentes de alimentación y varios tipos de soporte. Resultados: 60 minutos de ofrecimiento de alimento permite la alimentación de 95% de las ninfas. El promedio de oviposición diario/hembra fue de 2,7 huevos y no varío significativamente con el consumo de sangre de gallina o ratón. La duración promedio del ciclo de vida desde huevo hasta el estadio ninfa-V fue de 128,6 días. El uso de cartulina negra y plumas dentro de los frascos de cría mejora la oviposición. Ninfas-V alimentadas desde ninfa-I y pesadas a los 5 o 6 días permite un aprovechamiento del 89% de las ninfas. Conclusiones: Los resultados de este trabajo brindan conocimiento para la cría masiva y el uso de ninfas de Rhodnius pallescens en ensayos biológicos.

  14. Ecological aspects of Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae in palms of the Chapada do Araripe in Ceará, Brazil

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    Fernando Braga Stehling Dias

    2008-12-01

    Full Text Available The aim of this work is to present aspects related to the ecology of Rhodnius nasutus Stål, 1859 in palms from Chapada do Araripe in Ceará, Brazil. The following five species of palms were investigated: babaçu (Attalea speciosa, buriti (Mauritia flexuosa, carnaúba (Copernicia prunifera, catolé (Syagrus oleracea and macaúba-barriguda (Acrocomia intumescens. Fifth palms were dissected (10 specimens for each species. The overall infestation index was 86%, with a total of 521 triatomines collected. The Trypanosoma cruzi Chagas, 1909 Index was 16.8% and two insects presented mixed infection with Trypanosoma rangeli Tejera, 1920. A precipitin test showed that R. nasutus from palms of Chapada do Araripe are associated with opossum and bird although other possible bloodmeals were observed. Our results showing a high index of infestation of the palms as well as T. cruzi infection, the association of R. nasutus with the most diverse species of palms and proximity of these palms to houses demonstrate the importance of this area for sylvatic T. cruzi transmission and suggest the need for epidemiological surveillance in the region of the Chapada do Araripe.

  15. Ecological aspects of Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae) in palms of the Chapada do Araripe in Ceará, Brazil.

    Science.gov (United States)

    Dias, Fernando Braga Stehling; Bezerra, Cláudia Mendonça; Machado, Evandro Marques de Menezes; Casanova, Cláudio; Diotaiuti, Liléia

    2008-12-01

    The aim of this work is to present aspects related to the ecology of Rhodnius nasutus Stål, 1859 in palms from Chapada do Araripe in Ceará, Brazil. The following five species of palms were investigated: babaçu (Attalea speciosa), buriti (Mauritia flexuosa), carnaúba (Copernicia prunifera), catolé (Syagrus oleracea) and macaúba-barriguda (Acrocomia intumescens). Fifth palms were dissected (10 specimens for each species). The overall infestation index was 86%, with a total of 521 triatomines collected. The Trypanosoma cruzi Chagas, 1909 Index was 16.8% and two insects presented mixed infection with Trypanosoma rangeli Tejera, 1920. A precipitin test showed that R. nasutus from palms of Chapada do Araripe are associated with opossum and bird although other possible bloodmeals were observed. Our results showing a high index of infestation of the palms as well as T. cruzi infection, the association of R. nasutus with the most diverse species of palms and proximity of these palms to houses demonstrate the importance of this area for sylvatic T. cruzi transmission and suggest the need for epidemiological surveillance in the region of the Chapada do Araripe.

  16. Revalidation and redescription of Triatoma brasiliensis macromelasoma Galvão, 1956 and an identification key for the Triatoma brasiliensis complex (Hemiptera: Reduviidae: Triatominae

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    Jane Costa

    2013-09-01

    Full Text Available Triatoma brasiliensis macromelasoma is revalidated based on the results of previous multidisciplinary studies on the Triatoma brasiliensis complex, consisting of crossing experiments and morphological, biological, ecological and molecular analyses. These taxonomic tools showed the closest relationship between T. b. macromelasoma and Triatoma brasiliensis brasiliensis. T. b. macromelasoma is redescribed based on specimens collected in the type locality and specimens from a F1 colony. The complex now comprises T. b. brasiliensis, T. b. macromelasoma, Triatoma melanica, Triatoma juazeirensis and Triatoma sherlocki. An identification key for all members of the complex is presented. This detailed comparative study of the morphological features of T. b. macromelasoma and the remaining members of the complex corroborates results from multidisciplinary analyses, suggesting that the subspecific status is applicable. This subspecies can be distinguished by the following combination of features: a pronotum with 1+1 narrow brownish-yellow stripes on the submedian carinae, not attaining its apex, hemelytra with membrane cells darkened on the central portion and legs with an incomplete brownish-yellow ring on the apical half of the femora. Because the T. brasiliensis complex is of distinct epidemiological importance throughout its geographic distribution, a precise identification of its five members is important for monitoring and controlling actions against Chagas disease transmission.

  17. Peridomiciliary colonies of Triatoma vitticeps (Stal, 1859 (Hemiptera, Reduviidae, Triatominae infected with Trypanosoma cruzi in rural areas of the state of Espírito Santo, Brazil

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    Claudiney Biral dos Santos

    2005-08-01

    Full Text Available In Brazil, the colonization of human dwellings by triatomines occurs in areas with native vegetation of the caatinga or cerrado types. In areas of Atlantic forest such as in the Brazilian state of Espírito Santo, there are no species adapted to live in human habitations. The few autochthonous cases of Chagas disease encountered in Espírito Santo have been attributed to adult specimens of Triatoma vitticeps that invade houses from forest remnants. In recent years, the entomology unit of the Espírito Santo State Health Secretariat has recorded nymphs infected with flagellates similar to Trypanosoma cruzi in rural localities. Entomological surveys were carried out in the residences and outbuildings in which the insects were found, and serological examinations for Chagas disease performed on the inhabitants. Four colonies were found, all associated with nests of opossums (Didelphis aurita, 111 specimens of T. vitticeps, and 159 eggs being collected. All the triatomines presented flagellates in their frass. Mice inoculated with the faeces presented trypomastigotes in the circulating blood and groups of amastigotes in the cardiac muscle fibres. Serological tests performed on the inhabitants were negative for T. cruzi. Even with the intense devastation of the forest in Espírito Santo, there are no indications of change in the sylvatic habits of T. vitticeps. Colonies of this insect associated with opossum nests would indicate an expansion of the sylvatic environment into the peridomicile.

  18. Patrones electroforéticos de hemoproteínas salivares (nitroforinas de Rhodnius colombiensis y Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae

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    Andrea Arévalo

    2007-01-01

    Conclusión. Estos resultados demuestran la utilidad de la técnica para la diferenciación entre R. prolixus y R. colombiensis en adición a métodos morfométricos y moleculares previamente utilizados para diferenciar estas dos especies.

  19. Patrones electroforéticos de hemoproteínas salivares (nitroforinas) de Rhodnius colombiensis y Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae)

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    Andrea Arévalo; Julio César Carranza; Felipe Guhl; Gustavo Adolfo Vallejo

    2007-01-01

    Introducción. La electroforesis de hemeproteínas salivares en geles de almidón es una técnica de reciente aplicación para diferenciar especies del género Rhodnius que poseen gran similaridad fenotípica o para diferenciar subpoblaciones de la misma especie, separadas geográficamente. De las 15 especies de Rhodnius descritas en latinoamérica, por lo menos ocho han sido reportadas en el territorio colombiano. Objetivo. Utilizar la electroforesis de hemeproteínas salivares para diferenciar R. ...

  20. Sensibilidad de diferentes especies de Rhodnius (Hemiptera, Reduviidae, Triatominae a una cepa brasileña de Trypanosoma rangeli (SC58/KP1-

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    Daniella Barreto-Santana

    2015-03-01

    Materiales y métodos. Se seleccionaron treinta ninfas de cada especie después de xenodiagnóstico artificial en sangre infectada con T. rangeli. Se examinaron periódicamente muestras de heces y hemolinfa. Los insectos con hemolinfas infectadas fueron alimentados en ratones a fin de comprobar la transmisión por picadura y posteriormente disecados para confirmar la infección de las glándulas salivales. Resultados. En Rhodnius pictipes se encontró un mayor porcentaje de infección intestinal que en las otras especies. Se detectaron epimastigotes y tripomastigotes en la hemolinfa de las cuatro especies, y se encontró que el parasitismo fue menor en las especies del linaje R. robustus. Rhodnius robustus y R. neglectus no transmitían T. rangeli a ratones por picadura: después de la disección, sus glándulas no estaban infectadas. Solo un espécimen de R. nasutus y dos de R. pictipes transmitieron el parásito por la picadura. La tasa de infección glandular fue de 16 % para R. pictipes y de 4 % para R. nasutus. Conclusiones. La capacidad infecciosa (hemolinfática, intestinal y glandular y la transmisión de T. rangeli (SC-58/KP1- fueron mayores y más eficientes en R. pictipes. Estos resultados refuerzan la hipótesis de que estos triatominos actúan como filtros biológicos en la transmisión de T. rangeli.

  1. Ecoepidemiology and biology of Eratyrus mucronatus Stål, 1859 (Hemiptera: Reduviidae: Triatominae, a sylvatic vector of Chagas disease in the Brazilian Amazon

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    Gersonval Leandro Silva Monte

    2014-12-01

    Full Text Available Introduction Eratyrus mucronatus Stål, 1859 is a wild triatomine vector of Trypanosoma cruzi Chagas, 1909. However, little is known regarding the biology and ecoepidemiology of this triatomine in the Brazilian Amazon. The present study describes the biology of E. mucronatus grown under laboratory conditions and the epidemiological aspects of its natural breeding sites. Methods Five colonies were monitored in the field for 3 years. Temperature and humidity measurements were taken in the mornings and afternoons at the natural breeding sites, and the behavior and distribution of the nymphs and adults were observed in the wild colony. We also monitored the life cycle under controlled laboratory conditions. Results Some factors that were considered decisive for the establishment of these colonies were present at all of the colonies studied in the field. These factors included an active termite nest, a vertebrate for repast, and dry and shaded substrates with temperatures of 24-28°C and with humidity of 80-90%. A generation was developed in 274 days under these microclimatic conditions in the laboratory. Conclusions The climatic variables described in the field indicate that these environmental parameters have a limiting effect on the dispersal and colonization of E. mucronatus to new environments. In addition, the long period of development to adulthood demonstrates that only one generation can develop per year even under the more favorable laboratory conditions.

  2. Description of the feeding preferences of triatominae in the Chagas disease surveillance study for the State of Pernambuco, Brazil (Hemiptera: Reduviidae).

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    Silva, Maria Beatriz Araújo; Menezes, Kelly Reis de; Farias, Maria Clara Guerra de; Andrade, Maria Sandra; Victor, Caio Cesar Alves; Lorosa, Elias Seixas; Jurberg, José

    2017-01-01

    Studying the feeding preferences of triatomines is an important entomological surveillance tool, since continuous surveillance of the disease is necessary. The precipitin reaction was used to describe the feeding preferences of triatomines along with their natural infection by flagellates similar to Tyrpanosoma cruzi. Six hundred eighty-seven insects were examined, including Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus lutzi. Sixty-nine (10%) of 687 triatomines examined tested positive for flagellates similar to T. cruzi, and 8 (1.2%) of these fed on human blood. This study found potential transmitters of Chagas disease both inside and outside the domiciliar environment.

  3. Ecoepidemiology and biology of Eratyrus mucronatus Stål, 1859 (Hemiptera: Reduviidae: Triatominae), a sylvatic vector of Chagas disease in the Brazilian Amazon.

    Science.gov (United States)

    Monte, Gersonval Leandro Silva; Tadei, Wanderli Pedro; Farias, Thaysa Marinho

    2014-01-01

    Eratyrus mucronatus Stål, 1859 is a wild triatomine vector of Trypanosoma cruzi Chagas, 1909. However, little is known regarding the biology and ecoepidemiology of this triatomine in the Brazilian Amazon. The present study describes the biology of E. mucronatus grown under laboratory conditions and the epidemiological aspects of its natural breeding sites. Five colonies were monitored in the field for 3 years. Temperature and humidity measurements were taken in the mornings and afternoons at the natural breeding sites, and the behavior and distribution of the nymphs and adults were observed in the wild colony. We also monitored the life cycle under controlled laboratory conditions. Some factors that were considered decisive for the establishment of these colonies were present at all of the colonies studied in the field. These factors included an active termite nest, a vertebrate for repast, and dry and shaded substrates with temperatures of 24-28°C and with humidity of 80-90%. A generation was developed in 274 days under these microclimatic conditions in the laboratory. The climatic variables described in the field indicate that these environmental parameters have a limiting effect on the dispersal and colonization of E. mucronatus to new environments. In addition, the long period of development to adulthood demonstrates that only one generation can develop per year even under the more favorable laboratory conditions.

  4. First report of Triatoma sordida Stål, 1859 (Hemiptera, Reduviidae, Triatominae in the State of Acre and Brazilian Western Amazon

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    Leandro José Ramos

    Full Text Available Abstract INTRODUCTION The occurrence of Triatoma sordida in the Brazilian Western Amazon is reported for the first time. METHODS Triatoma sordida specimens were collected from a Gallus gallus nest in a peridomiciliary area of Senador Guiomard municipality in the state of Acre. RESULTS The number of triatomine species in Acre increased from six to seven with this first report of T. sordida in the Brazilian Western Amazon. CONCLUSIONS The occurrence of T. sordida in Acre is of concern since it is among the most captured triatomines in peridomiciliary environments in Brazil, and carries a high potential for vector transmission.

  5. Biology of Triatominae (Reduviidae, Hemiptera from north of formosa county (Goiás - Brazil II. Length of life cycle of Rhodnius Neglectus lent, 1954

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    Dalva A. Mello

    1977-04-01

    Full Text Available In the present paper the life cycle of Rhodnius neglectus was studied. The mean length from egg to adult was 119 days. The mean length in day from each stage was: 17.4 (± 1.15 for first, 18.2 (± 1.28 for second, fourth and 29.8 (± 1.46 for fifth.

  6. Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958 (Hemiptera: Reduviidae: Triatominae under laboratory conditions

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    Anita G Villacís

    2008-11-01

    Full Text Available Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD in Ecuador. The objective of this study was to describe (and compare the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region and Loja (Andean region]. Egg-to-adult (n = 57 development took an average of 189.9 ± 20 (Manabí and 181.3 ± 6.4 days (Loja. Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation ranged from 4 min 42 s [nymph I (NI] to 8 min 30 s (male; feeding time ranged from 14 min 45 s (NI-28 min 25 s (male (Manabí and from 15 min 25 s (NI-28 min 57 s (nymph V (Loja. The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p < 0.001. Defecation while feeding was observed in Manabí specimens from stage nymph III and in Lojan bugs from stage nymph IV. There was a gradual, age-related increase in the frequency of this behaviour in both populations. Our results suggest that R. ecuadoriensis has the bionomic traits of an efficient vector of Trypanosoma cruzi. Together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic R. ecuadoriensis populations in the coastal and Andean regions may have a significant impact for CD control in Ecuador and Northern Peru.

  7. Actualización de la distribución geográfica y ecoepidemiología de la fauna de triatominos (Reduviidae: Triatominae en Colombia

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    Felipe Guhl

    2007-01-01

    Se resalta la importancia de la vigilancia entomológica como herramienta indispensable para reforzar las estrategias de control de la transmisión de la enfermedad de Chagas, permitiendo también la evaluación del riesgo que representan las especies de triatominos silvestres en Colombia.

  8. Triatominae Biochemistry Goes to School: Evaluation of a Novel Tool for Teaching Basic Biochemical Concepts of Chagas Disease Vectors

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    Cunha, Leonardo Rodrigues; de Oliveria Cudischevitch, Cecília; Carneiro, Alan Brito; Macedo, Gustavo Bartholomeu; Lannes, Denise; da Silva-Neto, Mário Alberto Cardoso

    2014-01-01

    We evaluate a new approach to teaching the basic biochemistry mechanisms that regulate the biology of Triatominae, major vectors of "Trypanosoma cruzi," the causative agent of Chagas disease. We have designed and used a comic book, "Carlos Chagas: 100 years after a hero's discovery" containing scientific information obtained by…

  9. Transcriptome Analysis of the Triatoma infestans (Hemiptera: Reduviidae) Integument.

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    Calderón-Fernández, Gustavo M; Moriconi, Débora E; Dulbecco, Andrea B; Juárez, M Patricia

    2017-11-07

    The insect integument, formed by the cuticle and the underlying epidermis, is essential for insect fitness, regulation of lipid biosynthesis and storage, insect growth and feeding, together with development progress. Its participation in insecticide resistance has also been outlined. Triatoma infestans Klug (Hemiptera: Reduviidae) is one of the major vectors of Chagas disease in South America; however, genomic data are scarce. In this study, we performed a transcriptome analysis of the nymph integument in order to identify which genes are expressed and their putative role. Using the 454 GS-FLX sequencing platform, we obtained approximately 144,620 reads from the integument tissue. These reads were assembled into 6,495 isotigs and 8,504 singletons. Based on BLAST similarity searches, about 8,000 transcripts were annotated with known genes, conserved domains, and/or Gene Ontology terms.The most abundant transcripts corresponded to transcription factors and nucleic acid metabolism, membrane receptors, cell signaling, and proteins related to cytoskeleton, transport, and cell energy processes, among others. More than 10% of the transcripts-encoded proteins putatively involved in the metabolism of fatty acids and related components (fatty acid synthases, elongases, desaturases, fatty alcohol reductases), structural integument proteins, and the insecticide detoxification system (among them, cytochrome P450s, esterases, and glutathione transferases). Real-time qPCR assays were used to investigate their putative participation in the resistance mechanism. This preliminary study is the first transcriptome analysis of a triatomine integument, and together with prior biochemical information, will help further understandthe role of the integument in a wide array of mechanisms. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Morphometric Analysis of the Host Effect on Phenotypical Variation of Belminus ferroae (Hemiptera: Triatominae

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    Claudia Magaly Sandoval Ramirez

    2015-01-01

    Full Text Available The Triatominae subfamily includes hematophagous insects, well known for their role as vectors for the Trypanosoma cruzi parasite, etiologic agent of Chagas’ disease. Belminus ferroae is a triatomine that showed an increased demographic fitness when cockroaches were used as hosts. Here we compare the centroid size (CS and wing shape between B. ferroae parents and three successive generations (O1, O2, and O3 of their offspring fed on cockroaches or mice under laboratory conditions. Morphometric analysis of the wings bugs fed on cockroaches showed a significant reduction in CS in both sexes among all generations. Sexual size dimorphism (SSD was observed in the insects fed on cockroaches (O2 and O3, as well as those bugs fed on mice (O2. Differences in the shape of wings were observed between parental and offspring wings when fed on mice, but not in males (O1, O2, and O3 or females (O1 and O2 fed on cockroaches. There was a greater wing shape similarity between the cockroach-fed offspring and their parents according to the Mahalanobis distances. Our results support the idea of higher adaptation of this Triatominae with arthropod hosts.

  11. Nucleolar-persistence phenomenon during spermatogenesis in genus Meccus (Hemiptera, Triatominae).

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    Madeira, F F; Lima, A A C; Rosa, J A; Azeredo-Oliveira, M T V; Alevi, K C C

    2016-03-28

    The Triatominae subfamily consists of 150 species in 18 genera, grouped into six tribes. In cytogenetics, triatomines are important biological models because they have holocentric chromosomes and nucleolar persistence in meiosis. The phenomenon of nucleolar persistence has been described for 23 species of triatomine in three genera: Triatoma, Rhodnius, and Panstrongylus. However, new species and genera should be analyzed to assess whether nucleolar persistence is a peculiarity of Triatominae. Thus, this study aimed to analyze nucleolar behavior during spermatogenesis of Meccus pallidipennis and M. longipennis, focusing on the nucleolar-persistence phenomenon. Through the analysis of spermatogenesis, more specifically of meiotic metaphase, we observed the phenomenon of nucleolar persistence in M. pallidipennis and M. longipennis, represented by remnants of nucleolar material in metaphase. Thus, although nucleologenesis of new species, and, especially, new genera, should be analyzed, this study confirms for the first time the phenomenon of nucleolar persistence in the genus Meccus. Therefore, we emphasize the importance of new studies in this area in order to assess whether this phenomenon is truly a synapomorphy of these hematophagous insects.

  12. A Triatoma maculata (Hemiptera, Reduviidae, Triatominae population from Roraima, Amazon region, Brazil, has some bionomic characteristics of a potential Chagas disease vector Uma população de Triatoma maculata (Hemiptera, Reduviidae, Triatominae proveniente de Roraima, Amazônia, Brasil, possui algumas características bionômicas de vetor potencial de doença de Chagas

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    José Francisco Luitgards-Moura

    2005-06-01

    Full Text Available Even though Chagas disease is rare in the Brazilian Amazon, the conditions for the establishment of domiciliated cycles prevail in many areas where triatomines are of frequent occurrence. In Roraima, a previous serological and entomological survey in three agricultural settlements showed the existence of all transmission cycle elements, i.e., individuals infected by Trypanosoma cruzi, triatomine species previously found harboring T. cruzi in the broader Amazon region of neighboring countries and, domicile/ peridomicile conditions favorable to triatomine colonization. Triatoma maculata was the most frequent species, found in chicken houses in the peridomicile and sporadically within residences. Aiming to investigate the possibility of T. maculata to possess the potentiality to transmit T. cruzi in the area, bionomic characteristics were studied under laboratory conditions. These were feeding frequency, time for defecation after a blood meal, time elapsed in voluntary fasting pre- and pos-ecdysis, moulting time periods, pre-oviposition and oviposition periods and index of oviposition, incubation period, egg viability, longevity and mortality rate. Results show that the Passarão population of T. maculata should be considered a potential vector of T. cruzi since it shows a capacity to infest artificial ecotopes in the peridomicile, to carry out large number of meals during the nymphal cycle, to have a relatively short developmental cycle capable of producing 2.9 generations/year, to blood source eclecticism, to defecate immediately after the blood meal while still on the host and to the fact that has been previously found naturally infected by T.cruzi.A doença de Chagas é de rara ocorrência na Região Amazônica Brasileira, onde contudo as condições para o estabelecimento de ciclos domésticos existem. Um estudo previamente realizado em áreas de colonização agrícola no Estado de Roraima, mostrou a possibilidade de ciclos autóctones de transmissão virem a ocorrer uma vez que todos os elementos estavam lá presentes, indivíduos infectados por Trypanosoma cruzi, espécies de triatomíneos anteriormente descritas como infectadas por T. cruzi na Região Amazônica de países fronteiriços e, ambientes domiciliares e peri-domiciliares favoráveis à colonização de triatomíneos. Triatoma maculata foi a espécie mais frequentemente encontrada, tendo sido coletada em galinheiros no peridomicílio e esporadicamente nos domicílios. Visando investigar a potencialidade de T. maculata como espécie vetora na área, algumas características bionômicas foram estudadas em condições de laboratório incluindo freqüência de alimentação, tempo de defecação pós-prandial, tempo de jejum voluntário na pré- e na pós-ecdise, período inter-mudas, períodos de pré-oviposição e de oviposição, índice de oviposição, período de incubação, viabilidade dos ovos, índices de longevidade e de mortalidade. Os resultados mostraram que a população de T. maculata da Colônia Agrícola do Passarão deve ser considerada vetora em potencial do T. cruzi uma vez que mostrou capacidade de infestar ecótopos artificiais no peridomicílio, de se alimentar com freqüência durante o período ninfal, de possuir um ciclo de desenvolvimento relativamente curto com 2,9 gerações/ano, de possuir hábitos ecléticos de alimentação, de defecar imediatamente após a hematofagia quando ainda no hospedeiro e devido ao fato de ter sido previamente encontrada infectada por T. cruzi.

  13. Biologia do Triatoma vitticeps (Stal, 1859 em condições de laboratório (Hemiptera: Reduviidae: Triatominae: II. Resistência ao jejum Biology of Triatoma vitticeps (Stal, 1859 under laboratory conditions (Hemiptera: Reduviidae: Triatominae: II. Resistance to starvation

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    Teresa Cristina M. Gonçalves

    1989-03-01

    Full Text Available Em prosseguimento ao estudo da biologia do Triatoma vitticeps (Gonçalves et al., 1988, foram feitas observações sobre a sua resistência ao jejum. Dos 286 ovos obtidos, apenas 201 eclodiram e atingiram o estádio pretendido para as observações. Os demais não eclodiram, não completaram a muda ou morreram sem motivo aparente. As ninfas foram acondicionadas, individualmente em frascos de Borrel, devidamente registrados. Para a alimentação foram utilizados camundongos e a medida que as ninfas atingiam o estágio pretendido a alimentação era suspensa até ocorrer a morte. A avaliação da resistência ao jejum foi feita da seguinte forma: o intervalo de dias entre o último repasto e a morte e entre a muda e a morte. Verificou-se que a resistência está diretamente relacionada com a fase de desenvolvimento. Para os parâmetros último repasto/morte e muda/morte, ambos os sexos foram menos resistentes do que as ninfas de 3º e 2º estádios, respectivamente. O experimento teve duração de 15 meses e neste período as temperaturas máxima e mínima e a umidade relativa do ar variaram em média de 25 ± 2ºC e 81 ± 3% UR, respectivamente. O material foi proveniente da criação de triatomíneos mantida no Departamento de Entomologia do Instituto Oswaldo Cruz.Following the study on the biology of Triatoma vitticeps (Gonçalves et al. 1988 observations have been made on its resistance to starvation. Of the 286 eggs obtained only 201 hatched and reached the intended stage for observation. The others did not eclode, neither reached the ecdisis nor died, without explanation. The nymphs were kept, separately, in Borrel flasks and properly listed. The blood-meal was performed in mice, although the insects were kept without feeding as soon as moulted. The starvation was evaluated in two ways: the time-lapse in days between the last meal/death and between mult/death. The starvation was directly related with the developmental stage. In relation to the parameters las meal/death and moult/death, both sexes were less resistant than 3rd and 2nd stage, respectively. The experiment have been carried out for 15 months and by this time the average minimum and maximum temperatures and the humidity were 25 ± 2ºC and 81 ± 3% UR, respectively. The material spent belongs to the triatomine colony of the Oswaldo Cruz Institut Department of Entomology.

  14. A genitália externa dos machos de sete espécies de Triatoma Laporte, 1832 da região Neártica (Hemiptera, Reduviidae, Triatominae Male external genitalia in seven species of Triatoma Laporte, 1832 from neartic region (Hemiptera, Reduviidae, Triatominae

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    Herman Lent

    1987-06-01

    Full Text Available Sete espécies da região neártica: Triatoma barberi Usinger, 1939; T. rubida (Uhler, 1894; T. gertaeckeri (Stal, 1859; T. lecticularia (Stal, 1859; T. protracta (Uhler, 1894; T. recurva (Stal, 1868 e T. sanguisuga (Leconte, 1855 foram analisadas comparativamente, tendo como enfoque as estruturas da genitália do macho: falosoma (Ph, suporte do falosoma (SPh, processo do endosoma (PrEn, vesica (V e aparelho articular (Apb. As estruturas fálicas se mostraram capazes de serem usadas como critério morfológico suplementar aos padrões atualmente usados, em taxonomia. Estas espécies silvestres são encontradas nos Estados Unidos e México, naturalmente infectadas pelo T. cruzi; algumas vivem no perdomicílio e outras eventualmente no domicílio, sem contudo colonizá-lo.Seven species from the neartic region, Triatoma barberi Usinger, 1939; T. rubida (Uhler, 1894; T. gerstaeckeri (Stal, 1859; T. lecticularia (Stal, 1859; T. protracta (Uhler, 1894; T. recurva (Stal, 1868 and T. sanguisuga (Leconte, 1855 were comparatively analysed with emphasis on the genital structures of the male bug: the phallosome (Ph, the phallosome struts (SPh, the endosoma process (PrEn, the vesica (V and the articulatory apparatus (Apb. The phallic structures were useful as a supplementary morphological criterion to the present taxonomical standards. These wild species are found naturally infected by Trypanosoma cruzi in the United States and Mexico. Some of them live outside human dwellings while other are occasionally domiciliary, although they do not colonize these homes.

  15. Cinco especies nuevas de Pselliopus (Hemiptera: Heteroptera: Reduviidae: Harpactorinae: Harpactorini para México Five new species of Pselliopus (Hemiptera: Heteroptera: Reduviidae: Harpactorinae from Mexico

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    Harry Brailovsky

    2007-06-01

    Full Text Available Se describen 5 especies nuevas de Pselliopus Bergroth (Reduviidae: Harpactorinae recolectadas en México (Guerrero, Hidalgo, Jalisco, Michoacán, Nayarit, Nuevo León, Oaxaca, Puebla, Querétaro, San Luis Potosí, Sinaloa, Sonora y Tamaulipas y en los Estados Unidos de América (Arizona. Pselliopus karlenae Hussey se registra por primera vez para la República Mexicana. Se ilustran caracteres diagnósticos del pronoto, del borde posterior del segmento abdominal VII, de la cápsula genital del macho (pigóforo y parámeros. Se incluye una clave para la identificación de las especies basada principalmente en los genitales masculinos.Five new species of Pselliopus Bergroth (Reduviidae: Harpactorinae from Mexico (Guerrero, Hidalgo, Jalisco,Michoacán, Nayarit, Nuevo León, Oaxaca, Puebla, Querétaro, San Luis Potosí, Sinaloa, Sonora and Tamaulipas and from the United States of America (Arizona are described. Pselliopus karlenae Hussey is a new record for Mexico. Diagnostic taxonomic characters of pronotum, posterior border of abdominal segment VII, male genital capsule (pygophore and parameres are illustrated. An identification key based mainly on the male genitalia is included.

  16. Nucleolar Persistence: Peculiar Characteristic of Spermatogenesis of the Vectors of Chagas Disease (Hemiptera, Triatominae).

    Science.gov (United States)

    Madeira, Fernanda Fernandez; Borsatto, Kelly Cristine; Lima, Anna Claudia Campaner; Ravazi, Amanda; de Oliveira, Jader; da Rosa, João Aristeu; de Azeredo-Oliveira, Maria Tercília Vilela; Alevi, Kaio Cesar Chaboli

    2016-11-02

    All species of triatomines are considered potential vectors of Chagas disease and the reproductive biology of these bugs has been studied by different approaches. In 1999, nucleolar persistence during meiosis was observed in the subfamily for the first time. Recently, it has been observed that all species within the genus Rhodnius exhibit the same phenomenon, suggesting that it may be a synapomorphy of the triatomines. Thus, this article aims to analyze the nucleolar behavior during spermatogenesis of 59 triatomine species. All analyzed species exhibited nucleolar persistence during meiosis. Recently, it has been suggested that nucleolar persistence may be fundamental for the spermatogenesis of these vectors, since it is related to the formation of the chromatoid body. Therefore, we emphasize that this phenomenon is a peculiarity of the Triatominae subfamily and that further studies are required to analyze whether the nucleolar material that persists is active. © The American Society of Tropical Medicine and Hygiene.

  17. High dynamics of rDNA cluster location in kissing bug holocentric chromosomes (Triatominae, Heteroptera).

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    Panzera, Y; Pita, S; Ferreiro, M J; Ferrandis, I; Lages, C; Pérez, R; Silva, A E; Guerra, M; Panzera, F

    2012-01-01

    In this paper, we determine by fluorescent in situ hybridization the variability in the chromosomal location of 45S rDNA clusters in 38 species belonging to 7 genera of the Triatominae subfamily, using a triatomine-specific 18S rDNA probe. Our results show a striking variability at the inter- and intraspecific level, never reported so far in holocentric chromosomes, revealing the extraordinary genomic dynamics that occurred during the evolution in this group of insects. Our results also demonstrate that the chromosomal position of rDNA clusters is an important marker to disclose chromosomal differentiation in species karyotypically homogenous in their chromosome number. Copyright © 2012 S. Karger AG, Basel.

  18. Fungal flora of the digestive tract of Triatoma infestans (Hemiptera: Reduviidae from Argentina Flora fúngica de tractos digestivos en Triatoma infestans (Hemiptera: Reduviidae en Argentina

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    G. A. Marti

    Full Text Available A survey of the fungal microbiota of the digestive tract of Triatoma infestans (Klug (Hemiptera: Reduviidae adults was carried out. Insects captured in the field from different provinces in Argentina, as well as individuals reared in artificial colonies, were used for dissection. Axenic cultures of the fungal species were identified and were deposited with mycological collections at La Plata , Argentina. A total of 33 fungal species, with the exception of three that were mycelia sterilia, belonging to 11 genera were identified. Thirty two species belonged to Ascomycota (Eurotiomycetes and Sordariomycetes and one to Zygomycota (Zygomycetes. The genera with the greatest number of species were Penicillium (15, Aspergillus (5, and Cladosporium (2. Among the isolated fungi, some of the species were entomopathogenic or pathogens of humans and other animals.En el presente estudio se realizó un relevamiento de la flora fúngica microbiana en tractos digestivos de adultos de Triatoma infestans (Klug (Hemiptera: Reduviidae. Se disecaron insectos capturados del campo en diferentes provincias Argentinas, así como también se utilizaron individuos de una colonia artificial. Fueron realizados cultivos axénicos de las especies fúngicas aisladas, los que fueron identificados y luego depositados en las colecciones de hongos entomopatógenos del CEPAVE La Plata , Argentina. Fueron identificadas 33 especies fúngicas perteneciente a 11 géneros. Treinta y dos especies pertenecen a Ascomycota (Eurotiomycetes y Sordariomycetes y una a Zygomycota (Zygomycetes. Los géneros con mayor número de especies fueron Penicillium (15, Aspergillus (5, y Cladosporium (2. Entre los aislamientos fúngicos, algunas de las especies encontradas son entomopatogénicas o patógenas de humanos y otros animales.

  19. Predation of Apiomerus pilipes (Fabricius (Hemiptera, Reduviidae, Harpactorinae, Apiomerini over Meliponinae bees (Hymenoptera, Apidae, in the State of Amazonas, Brazil

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    Alexandre Coletto da Silva

    2004-12-01

    Full Text Available The present work shows the occurrence of an intense predatory activity on adults working Meliponinae bees (Hymenoptera, Apidae, by Apiomerus pilipes (Fabricius, 1787 (Hemiptera, Reduviidae, Harpactorinae, Apiomerini at a meliponary in the Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Amazonas State, Brazil.O presente trabalho registra a ocorrência de intensa atividade predatória de Apiomerus pilipes (Fabricius, 1787 (Hemiptera, Reduviidae, Harpactorini, Apiomerini sobre operárias adultas de meliponíneos (Hymenoptera, Apidae, no meliponário experimental do Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Estado do Amazonas, Brasil. O meliponário se encontra num fragmento de vegetação secundária no próprio INPA.

  20. Primer registro de Triatoma infestans (Klug (Hemiptera: Reduviidae asociado a nidos de loros barranqueros (Cyanoliseus patagonus (Aves: Psittacidae

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    María L. HERNÁNDEZ

    2015-01-01

    Full Text Available Triatoma infestans es el vector más importante de la enfermedad de Chagas de la Argentina. Se cita por primera vez la presencia de T. infestans (Klug (Hemiptera: Reduviidae asociado a nidos de loro barranquero Cyanoliseus patagonus (Psittasiformes: Psittacidae construidos en viviendas de adobe abandonadas. Se discuten las posibles implicancias de este hallazgo para la vigilancia entomológica del vector.

  1. Vinte e cinco anos de citogenética de Triatominae

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    Giorgio Schreiber

    1974-04-01

    Full Text Available É apresentado cronologicamente o ciclo de pesquisas de citogenética sobre os "barbeiros" no Departamento de Biologia Geral do ICB-UFMG desde 1948 até hoje. Foram, estudados o cariótipo e os cromossomos sexuais, os fenômenos de heteropicnose de autossomos e sua significação evolutiva, os fenômenos da síntese do DtNA ao longo do túbulo testicular, e a variabilidade da morfologia destes túbulos como caráter sistemático. Uma parte das pssquisas foi dedicada ao estudo dos mecanismos citogenéticos da esterilidade dos híbridos inter específicos.This paper deals wlth the cycle of cytogenetical researches on the Triatominae ("Kissing bugs" since 1948. It has been described the caryotypes and the problems of the multiple sex chromosomes, the existence in some species of the heteropycnosis of some autosomes and considered its significance in isolating mechanism in evolution. The chronology of the synthesis of DNA along the stages in the testicular tubes has been analyzed by autoradiography and cytometry. The significance of the differences in the number and relative sizes of the testicular tubules has been analyzed as taxonomic character. Part of these researches has been dedicated to the cytogenetic study of the male sterility of the interspecific hybrids.

  2. Demographic fitness of Belminus ferroae (Hemiptera: Triatominae on three different hosts under laboratory conditions

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    Claudia Magaly Sandoval

    2013-11-01

    Full Text Available Triatominae are widely recognised for their role as vectors of Trypanosoma cruzi. One of the main biological characteristics of this subfamily is their obligate haematophagous condition. However, previous studies on Belminus herreri and Belminus ferroae suggested that cockroaches are their principal hosts in domiciles. Due to this peculiar behaviour, the aim of this study was to analyse several demographic and reproductive parameters of B. ferroae fed on three different hosts (mice, cockroaches and Rhodnius prolixus and relate B. ferroae fitness to these alternative hosts. The cohorts were reared under constant conditions. The egg hatching rate was similar for cohorts fed on cockroaches (69.4% and R. prolixus (63.8%, but was much lower for the cohort fed on mice (16%. The development time from the nymph to adult stage and the average age of first reproduction (α presented lower values in the cohort fed on cockroaches, which is consistent with the higher population growth rate associated with this host. Demographic parameters [intrinsic rate of natural increase, finite rate of population growth, net reproductive rate and damping ratio] showed statistically significant differences between the cohorts. Analysis of the life history of B. ferroae revealed a higher fitness related to the cockroach. The implications of these results for the origin of the subfamily are discussed.

  3. Demographic fitness of Belminus ferroae (Hemiptera: Triatominae) on three different hosts under laboratory conditions.

    Science.gov (United States)

    Sandoval, Claudia Magaly; Medone, Paula; Nieves, Elsa Evelia; Jaimes, Diego Alexander; Ortiz, Nelcy; Rabinovich, Jorge Eduardo

    2013-11-01

    Triatominae are widely recognised for their role as vectors of Trypanosoma cruzi. One of the main biological characteristics of this subfamily is their obligate haematophagous condition. However, previous studies on Belminus herreri and Belminus ferroae suggested that cockroaches are their principal hosts in domiciles. Due to this peculiar behaviour, the aim of this study was to analyse several demographic and reproductive parameters of B. ferroae fed on three different hosts (mice, cockroaches and Rhodnius prolixus) and relate B. ferroae fitness to these alternative hosts. The cohorts were reared under constant conditions. The egg hatching rate was similar for cohorts fed on cockroaches (69.4%) and R. prolixus (63.8%), but was much lower for the cohort fed on mice (16%). The development time from the nymph to adult stage and the average age of first reproduction (α) presented lower values in the cohort fed on cockroaches, which is consistent with the higher population growth rate associated with this host. Demographic parameters [intrinsic rate of natural increase, finite rate of population growth, net reproductive rate and damping ratio] showed statistically significant differences between the cohorts. Analysis of the life history of B. ferroae revealed a higher fitness related to the cockroach. The implications of these results for the origin of the subfamily are discussed.

  4. Behavioral plasticity of Triatominae related to habitat selection in northeast Brazil.

    Science.gov (United States)

    de la Fuente, Ana Laura Carbajal; Dias-Lima, Artur; Lopes, Catarina Macedo; Emperaire, Laure; Walter, Annie; Ferreira, Agenor; Sherlock, Italo; Noireau, François

    2008-01-01

    Triatoma pseudomaculata Corrêa and Espínola, 1964 and Triatoma juazeirensis Costa and Felix, 2007 ( = T. brasiliensis Neiva, 1911 [part]), are sylvatic vectors of Trypanosoma cruzi (Chagas, 1909), the causative agent of Chagas disease, in northeast Brazil-especially in the caatinga region. In an area of caatinga in the State of Bahia, we compared the wild and peridomestic habitats of these two species of Triatominae to assess their behavioral plasticity in relation to habitat selection in different environments. In the sylvatic environment, the habitat of these two species is never shared. T. pseudomaculata is found in trees and bird nests, but without apparent preference for any particular tree species. In contrast, T. juazeirensis is exclusively rupicolous (found among rocks). Both species invade peridomestic structures but do not display a significant ability to colonize human dwellings. In the peridomestic area, they are highly adaptable to different habitats and can occupy substrates that they do not colonize in the sylvatic environment. This behavioral plasticity seems to be more striking in T. juazeirensis-rupicolous in sylvatic environments but colonizing wooden structures in the peridomicile in >80% of cases.

  5. The sialotranscriptome of the blood-sucking bug Triatoma brasiliensis (Hemiptera, Triatominae)

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    Santos, Adriana; Ribeiro, José Marcos C.; Lehane, Michael J.; Gontijo, Nelder Figueiredo; Veloso, Artur Botelho; Sant'Anna, Mauricio R.V.; Araujo, Ricardo Nascimento; Grisard, Edmundo C.; Pereira, Marcos Horácio

    2007-01-01

    Triatoma brasiliensis is the most important autochthon vector of Trypanosoma cruzi in Brazil, where it is widely distributed in the semiarid areas of the Northeast. In order to advance the knowledge of the salivary biomolecules of Triatominae, a salivary gland cDNA library of T. brasiliensis was mass sequenced and analyzed. Polypeptides were sequenced by HPLC/Edman degradation experiments. 1,712 cDNA sequences were obtained and grouped in 786 clusters. The housekeeping category had 24.4% and 17.8% of the clusters and sequences, respectively. The putatively secreted category contained 47.1% of the clusters and 68.2% of the sequences. Finally, 28.5% of the clusters, containing 14% of all sequences, were classified as unknown. The sialoma of T. brasiliensis showed a high amount and great variety of different lipocalins (93.8% of secreted proteins). Remarkably, a great number of serine proteases that were not observed in previous blood-sucking sialotranscriptomes were found. Nine Kazal peptides were identified, among them one with high homology to the tabanid vasodilator vasotab, suggesting that the Triatoma vasodilator could be a Kazal protein. PMID:17550826

  6. Prevalence and distribution of parasites and pathogens of triatominae from Argentina, with emphasis on Triatoma infestans and Triatoma virus TrV.

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    Marti, Gerardo A; Echeverria, María G; Susevich, María L; Becnel, James J; Pelizza, Sebastián A; García, Juan J

    2009-11-01

    Chagas' disease is the most important endemic arthropod-zoonosis in Argentina with an estimated 1.6 million people infected with the causative agent Trypanosoma cruzi. Triatoma infestans is the main vector of Chagas' disease in Argentina. A survey for parasites and pathogens of Triatominae was conducted from August 2002 to February 2005. Collections of insects were made in domiciles, peridomiciles, and in the natural habitats of the Triatominae. Insects from these collections were dissected and their organs and tissues examined for flagellates. Frass from these insects was collected and examined for detection of the entomopathogenic virus Triatoma virus (TrV) using AC-ELISA and PCR. Triatominae belonging to four species, T. infestans (n=1646), Triatoma guasayana (n=4), Triatoma platensis (n=1) and Triatoma sordida (n=5) were collected from 62 sites located in 13 provinces of Argentina. Triatoma virus and two protozoan species, Blastocrithidia triatomae and T. cruzi, the etiological agent of Chagas disease, were found infecting Triatominae. The total prevalence of TrV in 1646 T. infestans analyzed by ELISA was 9.66% (159/1646) from 7 to 13 provinces where collections were made. Triatoma virus positive triatomines were found in 17 of 62 populations when examined by AC-ELISA but in 38 of 62 populations when PCR was used for detection. The prevalence of B. triatomae in T. infestans was 0.43% (7/1646), while the prevalence of T. cruzi was 1.3% (21/1646). This is the first study on the diversity, distribution and prevalence of flagellated protozoa and TrV of Triatominae in endemic Chagas' disease regions of Argentina.

  7. First observation of alternative food usage (extrafloral nectar by the assassin bug Atopozelus opsimus (Hemiptera, Reduviidae

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    Rhainer Guillermo-Ferreira

    2012-12-01

    Full Text Available Assassin bugs (Reduviidae are voracious insects that prey on other arthropods. Recent evidences have pointed out that these predators also feed on plant derived substances in rare opportunities. The present study describes the feeding behavior of the reduviid Atopozelus opsimus on extrafloral nectaries of Inga vera (Fabaceae in a Neotropical savanna area. It was investigated if the insects feed more frequently of extrafloral nectar or prey, and if individuals of different stages of development vary according to feeding behavior. Notably, the results suggest that the diet of all instars and adults consist mainly of extrafloral nectar (N = 1013, in detriment of captured prey ingestion (N = 18. Also, there was no variation on feeding behavior and life stage.

  8. Triatominae biochemistry goes to school: evaluation of a novel tool for teaching basic biochemical concepts of Chagas disease vectors.

    Science.gov (United States)

    Cunha, Leonardo Rodrigues; Cudischevitch, Cecília de Oliveira; Carneiro, Alan Brito; Macedo, Gustavo Bartholomeu; Lannes, Denise; Silva-Neto, Mário Alberto Cardoso da

    2014-01-01

    We evaluate a new approach to teaching the basic biochemistry mechanisms that regulate the biology of Triatominae, major vectors of Trypanosoma cruzi, the causative agent of Chagas disease. We have designed and used a comic book, "Carlos Chagas: 100 years after a hero's discovery" containing scientific information obtained by seven distinguished contemporary Brazilian researchers working with Triatominaes. Students (22) in the seventh grade of a public elementary school received the comic book. The study was then followed up by the use of Concept Maps elaborated by the students. Six Concept Maps elaborated by the students before the introduction of the comic book received an average score of 7. Scores rose to an average of 45 after the introduction of the comic book. This result suggests that a more attractive content can greatly improve the knowledge and conceptual understanding among students not previously exposed to insect biochemistry. In conclusion, this study illustrates an alternative to current strategies of teaching about the transmission of neglected diseases. It also promotes the diffusion of the scientific knowledge produced by Brazilian researchers that may stimulate students to choose a scientific career. © 2014 The International Union of Biochemistry and Molecular Biology.

  9. Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae en el estado brasileño de "Rio Grande do Sul" Finding of Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae in the Brazilian State of "Rio Grande do Sul"

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    Roberto Salvatella

    1991-02-01

    Full Text Available Triatoma platensis Neiva 1913 (Hemiptera, Triatominae, especie ornitófila, con área de dispersión conocida en Argentina, Bolivia, Paraguay y Uruguay es notificada en un primer registro para Brasil. Hallada en el municipio de Uruguaiana (Río Grande do Sul en nidos de Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae donde cohabitaba con cricétidos de la especie Orizomys flavescens. Ningún ejemplar de los siete colectados se presentó infectado por Trypanosoma cruzi.Triatoma platensis, an ornitophilic species, found in Argentina, Bolivia, Paraguay and Uruguay is reported for the first time in Brazil. It was found in the county of Uruguaiana (Rio Grande do Sul in nests of Anumbius annumbi (Vieillot, 1817 (Passeriformes, Furnariidae where it cohabited with cricetids belonging to the species Orizomys flavescens. None of the seven individuals collected were infected by Trypanosoma cruzi.

  10. Ultrastructure and morphometry of eggs of Triatoma rubrovaria (Blanchard, 1843), Triatoma carcavalloi Juberg, Rocha & Lent, 1998 and Triatoma circummaculata (Stål, 1859) (Hemiptera-Reduviidae-Triatominae).

    Science.gov (United States)

    Cardozo-de-Almeida, Margareth; Castro-de-Souza, Simone; De Oliveira, Maria Luiza Ribeiro; De Almeida, Sérgio Antônio Silva; Gonçalves, Teresa Cristina Monte; Dos Santos-Mallet, Jacenir Reis

    2013-12-20

    This study analyzed the body and the operculum of eggs of Triatoma rubrovaria, T. carcavalloi and T. circummaculata, considered sylvatic species that live in sympatry.Triatoma rubrovaria is currently considered the most important vector of Trypanosoma cruzi in the rural areas of the state of Rio Grande do Sul, followed by T.circummaculata. Significant differences other than morphometry have been observed in the egg structures of the three species using traditional microscopy and scanning electron microscopy. Triatoma circummaculata eggs are smaller than those of T.rubrovaria and T. carcavalloi. The average number of perforations in corionic cells in the egg body is higher for the T. rubrovaria. The average number of perforations in the operculum cell is higher in T. circummaculata. This is the first morpho-structural description of T. carcavalloi eggs. These results widen the concept of these three species and create new subsidies for the entomological monitoring in areas in which these vectors may infest human living quarters.

  11. Estudos anatômicos e histológicos sôbre a subfamília Triatominae (Heteroptera, Reduviidae: V parte: anatomia do testículo e espermiocitogênese do Triatoma infestans

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    Rudolf Barth

    1956-06-01

    Full Text Available Neste trabalho, faz-se o estudo das estruturas anatômica e histológica do testículo de Triatoma infestans. Da espermiogênese, descrevem-se apenas as fases que medeiam entre a formação dos espermiogônios e a dos espermídeos (espermiocitogênese. A espermiohistogênese bem como as anatomias do vas deferens e das glândulas anexas serão tratados na segunda parte dêste trabalho, já em preparo. O testículo de Triatoma infestans possui 7 folículos dos quais cada um se abre num vas efferens próprio, curto, desembocando êstes num único vas deferens geral. Na zona de transição entre vas efferens e vas deferens, encontra-se sempre um conjunto de massas tissulares que se estão necrosando em virtude da decomposição das paredes dos cistos. Em conseqüência, os feixes de espérmios são libertados e passam através do vas efferens para o vas deferens. As substâncias líquidas que então se formam, resultado da necrose, são reabsorvidas pelo epitélio do vas efferens, entrando novamente em circulação na hemolinfa; o epitélio possui um rabdório muito longo. A parte superior do conteúdo de cada folículo dispõe-se ao redor de grande célula apical cuja função principal deve ser a de uma atividade reguladora que está relacionada com a diferenciação das células do conjunto germinativo em espermiogônios primários e em núcleos das paredes dos cistos. Nos espermiogônios, serão verificadas 8 divisões de multiplicação, o que vai dar a formação de 256 espermiócitos, número êsse que depois das duas divisões de maturação, que se seguem, originará 1 024 espermídeos. Em seguida, são descritos os fenômenos que ocorrem durante a prófase e as duas divisões de maturação. Temos que admitir a existência de uma parasíndese. Pela formação das tétrades, pode-se concluir que a primeira divisão é reducional e a segunda equacional, existindo, pois, uma pré-redução. Triatoma infestans possui 22 cromosomas no espermiogônio, dos quais 2 são heterocromosomas, sendo X, o maior e Y, o menor, pois, por observações comparadas de oogônios, verificou-se que o grande está ausente, enquanto o pequeno existe em número duplo. Os autosomas da guarnição equatorial, reduzidos pela primeira e segunda divisões de maturação, podem ser distribuídos, quanto ao seu tamanho, em três grupos: 3 grandes (A,B e C, 2 médios (D e E e 5 pequenos (F, G, H, I e K. A, B e C, bem como os heterocromosomas, são heteropicnóticos, formando, tanto nos espermiogônios como nos espermiócitos, depois da sinapsis, um corpo de 8 valores, respectivamente de 5 valores, corpos êsses que permanecem fortemente condensados, mesmo quando os outros cromosomas se individualizam ou quando formam os cromosomas difusos. O estádio dos cromosomas é analisado e considerado como uma fase ativa durante o tempo do crescimento intensivo dos espermiócitos.

  12. Biologia de Rhodnius stali, Lent, Jurberg & Galvão e Rhodnius pictipes Stål (Hemiptera, Reduviidae, Triatominae em condições de Laboratório.

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    Solange Peixoto

    2014-12-01

    Abstract. Rhodnius stali Lent, Jurberg & Galvão is a Chagas Disease vector that colonize houses in the Alto Beni region, Bolivia and its biology is poorly known. Aiming to enhance the understanding about their biology, we observed a few parameters of its life cycle, at nymphal stages, comparing them with Rhodnius pictipes Stål a morphologically similar and phylogenetically close species. The following parameters were observed: time of hatching, development time from egg to adult (male and female separately, mortality rate, age at first blood meal and blood volume ingested by nymphs. In general, it was observed that the R. stali has longer cycle than R. pictipes, and in both species, the time between hatching the egg to adult in females is lower. Interestingly for R. stali, which is known to be capable of colonizing households, the mortality rate of nymphs was higher than observed in R. pictipes, something unexpected for species that colonize artificial structures and was observed in artificial environment. For R. stali, the first blood meal was, on average, four days later than for R. pictipes, species that ingested a greater total blood volume, possibly because of its bigger size. By knowing in depth the biological aspects of these species it will be possible to direct vector control more accurately, especially in regions where they colonize houses, as in the Alto Beni, Bolivia.

  13. Comparación del ciclo de vida de Rhodnius colombiensis Moreno, Jurberg & Galvão, 1999 y Rhodnius prolixus Stal, 1872(Hemiptera, Reduviidae, Triatominae en condiciones de laboratorio

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    Andrea Arévalo

    2007-01-01

    Resultados. Los promedios de duración de todos los estadios de desarrollo de R. colombiensis fueron mayores que en R. prolixus, presentando diferencias significativas en el tiempo transcurrido desde huevo hasta adulto. Los promedios de huevos puestos y huevos fértiles, presentaron diferencias significativas, siendo mayores en R. prolixus que en R. colombiensis. El porcentaje total de mortalidad de R. colombiensis fue de 31,5% y de 6,5% para R. prolixus. La longevidad en las hembras fue mayor en R. prolixus. Conclusiones. Los estadios de R. prolixus tienen menor duración, las ninfas en general realizan menor número de comidas que R. colombiensis, los adultos de R. prolixus toman mayor número de comidas y ovipositan mayor número de huevos fértiles, presentando hembras con mayor longevidad. Todos estos parámetros indican que R. prolixus presenta mejor éxito reproductivo que R. colombiensis, en las condiciones experimentales utilizadas. Los datos inéditos sobre el ciclo de vida de R. colombiensis serán de utilidad para el mantenimiento de las colonias en el laboratorio.

  14. Estudos anatômicos e histológicos sobre a subfamília Triatominae (Heteroptera, Reduviidae: Parte XXIII: o ovário de triatoma infestans

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    Rudolf Barth

    1973-01-01

    Full Text Available Descreve-se microanotômico e histologicamente o ovário de Triatoma infestans sob o ponto de vista de sua função. O ovário é do tipo meroístico-telotrófico. a túnica própria é uma membrana dupla, das quais a lamela interna isola o germário do filamento terminal. O estrato germinativo é limitado a uma zona estreita atrás do volumoso grupo de células nutridoras. Os oócitos, ainda dentro do estrato germinativo, percorrem os estados da prófase até a sinapses, cujos filamentos cromáticos se desintegram. Em todas as zonas do germário, todos os tipos de células são bem individualizadas, não se observa um índice de formação de sincício. Inicialmente, o epitélio folicular é composto de várias camadas de células mononucleadas. Com o crescimento do oócito o epitélio torna-se simples com células binucleadas em conseqüência de amitoses. O pedúnculo ovariolar possui uma glândula circular.Microanotomy and histology of the ovary of Triatoma infestans are described under the view point of its funcion. The ovary is of the meroistic-telotrophic type. The Tunica propria is a dobble membrane, the internal one divides the germarium from the therminal filament. The stratum germinativum is limited to a strait zone behind the volumous group of food cells. The oocytes, within the stratum germinativum, show the prophase figures up till the synapsis, when the cromatic filaments soon desintegrate. In all zones of the terminal chamber all types of cells are well individualized, there is no sign of syncytium to be found. In the beginning of formation the follicle epithelium is formed by some layers of cells with only one nucleus. During the growth of the oocyte, the epithelium shows only one layer of cells with two nuclei as consequence of an amitosis. The pedicel of the ovariolum has a circular gland.

  15. A new species and karyotype variation in the bordering distribution of Mepraia spinolai (Porter) and Mepraia gajardoi Frías et al (Hemiptera: Reduviidae: Triatominae) in Chile and its parapatric model of speciation.

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    Frías-Lasserre, Daniel

    2010-01-01

    In the present study, the morphology, color pattern, chromosomal complement and aspects of meiosis in natural populations at the borders of the distributions of Mepraia gajardoi Frías et al and Mepraia spinolai (Porter) are described. The males of these bordering populations are brachypterous or macropterous, while females are always micropterous. Morphological and cytogenetic data indicated that the populations that border the distributions of M. gajardoi and M. spinolai, belong to a different species of parapatric origin.

  16. Estudo morfológico comparativo de ovos e ninfas de Triatoma maculata (Erichson, 1848 e Triatoma pseudomaculata Corrêa & Espínola, 1964 (Hemiptera, Reduviidae, Triatominae

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    Teresa Cristina Monte Goncalves

    1985-09-01

    Full Text Available Utilizando a microscopia ótica (MO e eletrônica de varredura (MEV procurou-se fornecer dados a taxionomia através da estrutura dos ovos e morfologia das ninfas, destes vetores da doença de Chagas. Os ovos em MO apresentam a superfície exocorial do opérculo e do corpo dividida em áreas poligonais com ornamentação própria; em T. maculata o exocório do corpo tem áreas indefinidas. Em MEV o exocório dos opérculos apresenta áreas poligonais de superfície estofada com pequena sulcos irregulares e perfurações distribuídas aleatoriamente nas duas espécies. O exocório do corpo apresenta: em T. maculata áreas acolchoadas com perfurações mais numerosas nos bordos, visualizando-se a borda corial, goteira espermática, aerópilas e micrópilas; em T. pseudomaculata as áreas são planas com numerosas perfurações. Nas ninfas o sulco estridulatório e o rostro apresentam diferenças significativas. O sulco estridulatórios em MO possibilitou diferenciar ninfas de 1º, 2º e 3º estádios, os 4º e 5º estádios apresentam-se semelhantes. Em MEV a diferenciação é acentuada. O rostro em MO apresenta pilosidade característica a partir do 3º estádio. T. maculata apresenta pêlos curtos e esparsos no 1º e 2º artículos e longos e numerosos no 3º, em T. pseudo-maculata semelhantes, porém mais curtos no 3º artículo.As an aid in the identification of vectors of Chagas' disease we have studied the structure of the eggs and morphology of nymphs by optical microscopy (OM and scanning electron microscopy (SEM. The eggs as seen by OM show the exochorion of the body doesn't have defined areas. In SEM the exochorion of the cap appears as upholstered polygonal areas with small irregular grooves and perforations spread at random in both species. The exochorion of the body in T. maculata is upholstered with more numerous perforations on the edge visualizing the rim of the shell, spermatic groove, pseudomicropyles and micropyles; in T. pseudomaculata there are flat areas with numerous perforations. The nymphs show differences cencerning the stridulatory groove and rostrum. The stridulatory groove when seen by OM shows differences in nymphs of 1st, 2nd and 3rd intars, while 4th and 5th are similar; in SEM the differences are clear. In OM the rostrum shows typical pilosity to each species from 3rd instar. In T. maculata the setae are short and scattered on the 1st and 2nd segments and are long and numerous on the 3rd. In T. pseudomaculata the setae are similar but are short on the 3rd segment.

  17. [Prevalence of triatomines (Hemíptera: Reduviidae: Triatominae) infected by Trypanosoma cruzi: seasonality and distribution in the Ciénega region of the State of Jalisco, Mexico].

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    Gómez-Hernández, César; Rezende-Oliveira, Karine; Zárate, Agustín Cortés; Zárate, Esperanza Cortés; Trujillo-Contreras, Francisco; Ramirez, Luis Eduardo

    2008-01-01

    The physical and geographical characteristics of the Ciénega region, Jalisco, Mexico make it suitable for transmission of Trypanosoma cruzi, the causative agent for Chagas disease. This study characterizes the prevalence of triatomines infected by this parasite, their seasonality and their distribution in this region. A total of 328 triatomines were evaluated between January 2005 and June 2007, from 13 municipalities in the region. April, May and June were the months with the highest capture levels. Among the triatomines examined, 57.3% were positive for Trypanosoma cruzi, corresponding to 15.4% in urban areas and 84.6% in rural areas. The species with greatest prevalence was Triatoma longipennis and the species with the highest parasitism rate was Triatoma barberi, with an infection rate of 83.3%, whereas the rate for Triatoma longipennis was 67.5% (p<0.05). This natural infection in the captured vectors may indicate that individuals in this region have high exposure to Trypanosoma cruzi. The recent findings of positive Triatoma dimidiata in this region suggest that new species are becoming adapted to the ecological conditions of these populations.

  18. Comparación de los patrones de alimentación y defecación de Rhodnius colombiensis y Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae en condiciones de laboratorio

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    Andrea Arévalo

    2007-01-01

    Conclusión. R. colombiensis presenta menor número de defecaciones que R. prolixus durante la comida. Un mayor porcentaje de R. prolixus defecan durante los 10, 60 y 95 min después de la alimentación. Sin embargo, R. colombiensis permanece mayor tiempo asociado al hospedero vertebrado, lo cual aumentaría la probabilidad de transmisión teniendo en cuenta el ingreso ocasional de los adultos a las viviendas humanas y sus elevadas prevalencias con T. cruzi y T. rangeli.

  19. Estudos anatômicos e histológicos sôbre a subfamília Triatominae (Heteroptera, Reduviidae: VII. Estudo anatômico do ducto intestinal do Triatoma infestans

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    Dyrce Lacombe

    1957-05-01

    Full Text Available Devido à imprtãncia que certos Triatomíneos hematófagos representam na vida humana, continuarmos a série de estudos já iniciados em nosso laboratório sôbre seus organismos. É feito, no presente trabalho, a anatomia e microanatomai do aparelho digestivo de Triatoma infestans. Das três distintas regiões do duto intestinal estomodeo, mesêntero e proctodeo, a primeira e a terceira são de origem ectodérmica. A região do estomodeo é constituída pela faringe e esôfago; a do proctodeo pelo piloro, íleo e reto. A segunda, de origem endodérmica, consta promesêntero, postmesêntero e da zona de transição. A anatomia e a microanatomia do faringe já foi estudada minuciosamente por BARTH (1952. O esôfago possui numerosas dobras no seu interior revestida de fina cutícula. A musculatura longitudinal e circular acham-se representadas por feixes que, provàvelmente, trabalham, preistàlticamente, transportando o alimento. Não encontramos um proventrículo, de maneira que o esôfago está ligado diretamente à primeira parte endodérmica, isto é, ao promesêntero. No início do promesêntero existe a válvula cardíaca, que, juntamente com as dobras do fim do esôfago, impedem que haja um refluxo do alimento. Durante a alimentação, a parede do preomesêntero, que apresenta numerosas dobras, sofre uma dilatação, a fim de reter u'a maior quantidade de sangue. Entre promesêntero e postmesêntero há um pequeno esfíncter formado pelo aumento da musculatura e das dobras do epitélio. O postmesêntero alcança cinco vêzes mais que o tamanho total do corpo do inseto, e dispõe no abdome em curvas completas, que, muitas vêzes, se superpõem. O seu epitélio possue célula altas e estreitas, e forma muitas dobras para dentro do seu lume. Na parte apical as células possuem um rabdório. O postmesêntero termina após a válvula cardíaca situada atrás do desembocamento das quatro ampolas dos tubos de Malpighi. Entre postmesêntero e proctodeo está situada a zona de transição, que é constituída pelas ampolas dos tubos de Malpighi, válcula pilórica e zona clara de células cubóides. Os quatro tubos de Malpighi são longos, finos e simples formando emaranhados. As ampolas são dilatações das bases dos tubos de Malpighi. Apresentam sempre células características. A formação da válvula pilórica pode ser acompanhada na série de cortes de 27-44. O piloro é revestido, internamente, por fina cutícula, e sua hipoderme é sinsicial. No íleo temos dobras mais elevadas e maior quantidade de musculatura. O reto acha-se deslocado para a região dorsal do corpo devido ao aumento exagerado do aparelho copulador. As células de sua hipoderme são bem limitadas.

  20. [Biogeography, origin, and distribution of triatominae domiciliarity in Brazil. Revista de Saúde Pública, 14(3):265-99, 1980].

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    Forattini, Oswaldo Paulo

    2006-12-01

    An association is established between the Brazilian geographical pattern of the domiciliarity of the triatominae bugs and open lands characterized by natural savanna vegetation or artificial, man-made landscapes. The Brazilian open lands involved are the "caatingas'' and "cerrados", both wholly included in Brazilian territory, while the mixed Southern subtropical prairies belong to systems extending bevond national boundary lines. The other open lands are anthropic-lands opened mainly by the destruction of primitive forests of the tropical Atlantic system. Attempts were made to subject the four synanthropic species of epidemiological importance to model paleoecologic refuges and endemic centers. Triatoma sordida, Triatoma brasiliensis, and Triatoma pseudomaculata seem to have their endemic centers in the "cerrados" and "caatinga", while the Panstrongylus megistus may have originated in the tropical Atlantic forest system. The Triatoma infestans, however, seem to have originated in Bolivia, then were spread to large dispersal regions by man. Thus it can be assumed that domiciliarity is arrived at through an opportunistic mechanism stimulated by shelter and food availability factors. Once established, domiciliarity favors the species survival and dispersal, and this is of particular interest to control and surveillance programs because it increases the probability of the triatominae's success in synanthropic specialization. The present intense anthropic activities in the Amazonian system will lead to even greater expansion into the open lands; consequently, a triatominae domiciliarity spread can be expected, due to either autochthonous or man-introduced populations. A public health problem will then arise in a region where it has, heretofore, been unknown.

  1. Prevalência de triatomíneos (Hemíptera: Reduviidae: Triatominae infectados por Trypanosoma cruzi: sazonalidade e distribuição na região Ciénega do Estado de Jalisco, México Prevalence of triatomines (Hemíptera: Reduviidae: Triatominae infected by Trypanosoma cruzi: seasonality and distribution in the Ciénega region of the State of Jalisco, Mexico

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    César Gómez-Hernández

    2008-06-01

    Full Text Available As características físico-geográficas da região Ciénega, Jalisco, México a tornam propícia para transmissão do Trypanosoma cruzi, causador da doença de Chagas. Este trabalho caracteriza a prevalência de triatomíneos infectados pelo parasita, sua sazonalidade e distribuição nesta região. Foram analisados 328 triatomíneos no período de janeiro de 2005 a junho de 2007 procedentes de 13 municípios da região, sendo abril, maio e junho os meses de maior captura. Dos triatomíneos analisados, 57,3% foram positivos para Trypanosoma cruzi, correspondendo 15,4% para a área urbana e 84,6% para a área rural. A espécie mais freqüente foi Triatoma longipennis e a mais parasitada foi Triatoma barberi com índice de infecção de 83,3% quando comparada a Triatoma longipennis (67,5% (pThe physical and geographical characteristics of the Ciénega region, Jalisco, Mexico make it suitable for transmission of Trypanosoma cruzi, the causative agent for Chagas disease. This study characterizes the prevalence of triatomines infected by this parasite, their seasonality and their distribution in this region. A total of 328 triatomines were evaluated between January 2005 and June 2007, from 13 municipalities in the region. April, May and June were the months with the highest capture levels. Among the triatomines examined, 57.3% were positive for Trypanosoma cruzi, corresponding to 15.4% in urban areas and 84.6% in rural areas. The species with greatest prevalence was Triatoma longipennis and the species with the highest parasitism rate was Triatoma barberi, with an infection rate of 83.3%, whereas the rate for Triatoma longipennis was 67.5% (p<0.05. This natural infection in the captured vectors may indicate that individuals in this region have high exposure to Trypanosoma cruzi. The recent findings of positive Triatoma dimidiata in this region suggest that new species are becoming adapted to the ecological conditions of these populations.

  2. Filling dynamics of the Brindley's glands in the blood-sucking bug Triatoma infestans (Hemiptera: Reduviidae).

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    Palottini, Florencia; González, Andrés; Manrique, Gabriel

    2014-12-01

    The filling dynamics of exocrine defensive glands is an important component of the defensive capacity of an insect in its natural environment. We studied the filling state and reloading rate of the Brindley's glands in the haematophagous Chagas disease vector Triatoma infestans (Hemiptera: Reduviidae). Quantitative analyses of isobutyric acid, the main secretion component, were carried out with glands dissected from adults under different scenarios of development, number of discharging events and feeding conditions. The alarm-pheromone function of the gland secretion was also assessed in bioassays with conspecific nymphs. Although pharate adults have their glands completely developed, these were not full until imaginal ecdysis. If kept undisturbed, the adults maintained a constant gland load, and discharged about 75% of the gland contents upon one disturbance event. While the glands can be discharged several times, full replenishing was not complete after one week, unless the insect had access to food. The escape behavior of nymphs in bioassays correlated with the chemical analyses, with nymphs showing significant avoidance only toward gland discharges from undisturbed or disturbed/fed adults. The results are discussed in reference to the feeding frequency and gregarious behavior of T. infestans under natural conditions, which suggest a relevant role of the filling dynamics of the Brindley's glands in the intraspecific communication of the insect. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Stage-Dependent Expression of Deltamethrin Toxicity and Resistance in Triatoma infestans (Hemiptera: Reduviidae) From Argentina.

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    Germano, Mónica D; Picollo, María I

    2018-02-20

    Triatoma infestans Klug (Hemiptera: Reduviidae) is the main vector of Chagas disease in Latin America. This insect has been controlled with pyrethroids since the 1980s, although the emergence of resistance to deltamethrin has decreased control success in some areas of the Gran Chaco ecoregion. The response of T. infestans to deltamethrin was evaluated per developmental stage. In addition, we evaluated the possible stage-dependent expression of deltamethrin resistance. The bioassays were conducted by topical application of the insecticide in acetone. The drop size, age at the time of exposure, and mortality measuring time were standardized per stage. The lethal dose of deltamethrin moderately increased with the developmental stage. The resistance to deltamethrin was expressed in every instar, and was the highest in the fourth- and fifth-instar nymphs. While increasing, weight plays a relevant role in lethal dose stage dependency, a number of contributing factors such as degradative metabolism are probably involved in the variability of insecticide effect and resistance described for different T. infestans developmental stages. Possible explanations for these differences and their implications on resistance management and chemical control are discussed.

  4. First record of Triatoma maculata (Erichson, 1848 (Hemiptera: Reduviidae: Triatomini in Riohacha, La Guajira – Colombia

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    Edith Natalia Gómez-Melendro

    2014-11-01

    Full Text Available Introduction. Knowledge of vector insect species, their habitat and geographical distribution is crucial for determining the risk of transmission of the etiologic agents that cause disease in humans, which allows defining strategies for prevention, surveillance and control in line with the characteristics of each area. Objective. To determine the presence and public health importance of vectors of Chagas disease in the indigenous settlements of Marbacella and El Horno of the Wayúu ethnic group in the municipality of Riohacha, La Guajira, Colombia. Materials and methods. From active search, installation and inspection of biosensors and occasional catches, Hemiptera: Reduviidae: Triatomini were collected intra and in the peridomicile housing of the indigenous settlements of El Horno and Marbacella of the the Wayúu ethnic group. Indices of intra and peridomestic infestation, colonization, density, dispersion and natural infection with Trypanosoma cruzi Chagas, 1909 were calculated. Results. 79.6% (n = 90 of the specimens were collected around the homes and 20.3% (n = 23 inside the homes, all corresponding to Triatoma maculata (Erichson, 1848. The natural infection indices with T. cruzi accounted for 43.5% for Marbacella and 36% for El Horno. Conclusion. This is the first reported capture of individuals of T. maculata, considered a secondary vector of Chagas disease in Colombia, naturally infected with T. cruzi in the municipality of Riohacha expanding the geographical distribution of the species in the department of La Guajira.

  5. Resin gathering in neotropical resin bugs (Insecta: Hemiptera: Reduviidae): functional and comparative morphology.

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    Forero, Dimitri; Choe, Dong-Hwan; Weirauch, Christiane

    2011-02-01

    Apiomerini (Reduviidae: Harpactorinae) collect plant resins with their forelegs and use these sticky substances for prey capture or maternal care. These behaviors have not been described in detail and morphological structures involved in resin gathering, transfer, and storage remain virtually undocumented. We here describe these behaviors in Apiomerus flaviventris and document the involved structures. To place them in a comparative context, we describe and document leg and abdominal structures in 14 additional species of Apiomerini that represent all but one of the 12 recent genera in the tribe. Based on these morphological data in combination with the behavioral observations on A. flaviventris, we infer behavioral and functional hypotheses for the remaining genera within the tribe Apiomerini. Setal abdominal patches for resin storage are associated with maternal care so far only documented for species of Apiomerus. Based on the occurrence of these patches in several other genera, we propose that maternal care is widespread within the tribe. Ventral abdominal glands are widespread within female Apiomerini. We propose that their products may prevent hardening of stored resins thus providing long-term supply for egg coating. Judging from the diverse setal types and arrangements on the front legs, we predict six different behavioral patterns of resin gathering within the tribe. Copyright © 2010 Wiley-Liss, Inc.

  6. Sylvatic host associations of Triatominae and implications for Chagas disease reservoirs: a review and new host records based on archival specimens

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    Anna Y. Georgieva

    2017-09-01

    Full Text Available Background The 152 extant species of kissing bug include important vectors of the debilitating, chronic, and often fatal Chagas disease, which affects several million people mainly in Central and South America. An understanding of the natural hosts of this speciose group of blood-feeding insects has and will continue to aid ongoing efforts to impede the spread of Chagas disease. However, information on kissing bug biology is piecemeal and scattered, developed using methods with varying levels of accuracy over more than 100 years. Existing host records are heavily biased towards well-studied primary vector species and are derived from primarily three different types of observations, associational, immunological or DNA-based, with varying reliability. Methods We gather a comprehensive and unparalleled number of sources reporting host associations via rigorous targeted searches of publication databases to review all known natural, or sylvatic, host records including information on how each record was collected. We integrate this information with novel host records obtained via attempted amplification and sequencing of a ∼160 base pair (bp region of the vertebrate 12S mitochondrial gene from the gastrointestinal tract of 64 archival specimens of Triatominae representing 19 species collected primarily in sylvatic habitats throughout the southern United States and Central and South America during the past 10 years. We show the utility of this method for uncovering novel and under-studied groups of Triatominae hosts, as well as detecting the presence of the Chagas disease pathogen via Polymerase Chain Reaction (PCR of a ∼400 bp sequence of the trypanosome 18S gene. Results New host associations for several groups of arboreal mammals were determined including sloths, New World monkeys, coatis, arboreal porcupines and, for the first time as a host of any Triatominae, tayras. A thorough review of previously documented sylvatic hosts, organized by

  7. Sylvatic host associations of Triatominae and implications for Chagas disease reservoirs: a review and new host records based on archival specimens.

    Science.gov (United States)

    Georgieva, Anna Y; Gordon, Eric R L; Weirauch, Christiane

    2017-01-01

    The 152 extant species of kissing bug include important vectors of the debilitating, chronic, and often fatal Chagas disease, which affects several million people mainly in Central and South America. An understanding of the natural hosts of this speciose group of blood-feeding insects has and will continue to aid ongoing efforts to impede the spread of Chagas disease. However, information on kissing bug biology is piecemeal and scattered, developed using methods with varying levels of accuracy over more than 100 years. Existing host records are heavily biased towards well-studied primary vector species and are derived from primarily three different types of observations, associational, immunological or DNA-based, with varying reliability. We gather a comprehensive and unparalleled number of sources reporting host associations via rigorous targeted searches of publication databases to review all known natural, or sylvatic, host records including information on how each record was collected. We integrate this information with novel host records obtained via attempted amplification and sequencing of a ∼160 base pair (bp) region of the vertebrate 12S mitochondrial gene from the gastrointestinal tract of 64 archival specimens of Triatominae representing 19 species collected primarily in sylvatic habitats throughout the southern United States and Central and South America during the past 10 years. We show the utility of this method for uncovering novel and under-studied groups of Triatominae hosts, as well as detecting the presence of the Chagas disease pathogen via Polymerase Chain Reaction (PCR) of a ∼400 bp sequence of the trypanosome 18S gene. New host associations for several groups of arboreal mammals were determined including sloths, New World monkeys, coatis, arboreal porcupines and, for the first time as a host of any Triatominae, tayras. A thorough review of previously documented sylvatic hosts, organized by triatomine species and the type of observation

  8. Assessing the mitochondrial DNA diversity of the Chagas disease vector Triatoma sordida (Hemiptera: Reduviidae).

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    Pessoa, Grasielle Caldas D'Ávila; Sousa, Tais Nóbrega de; Sonoda, Ivan Vieira; Diotaiuti, Liléia

    2016-05-01

    Triatoma sordida is a species that transmits Trypanosoma cruzi to humans. In Brazil, T. sordida currently deserves special attention because of its wide distribution, tendency to invade domestic environments and vectorial competence. For the planning and execution of control protocols to be effective against Triatominae, they must consider its population structure. In this context, this study aimed to characterise the genetic variability of T. sordida populations collected in areas with persistent infestations from Minas Gerais, Brazil. Levels of genetic variation and population structure were determined in peridomestic T. sordida by sequencing a polymorphic region of the mitochondrial cytochrome b gene. Low nucleotide and haplotype diversity were observed for all 14 sampled areas; π values ranged from 0.002-0.006. Most obtained haplotypes occurred at low frequencies, and some were exclusive to only one of the studied populations. Interpopulation genetic diversity analysis revealed strong genetic structuring. Furthermore, the genetic variability of Brazilian populations is small compared to that of Argentinean and Bolivian specimens. The possible factors related to the reduced genetic variability and strong genetic structuring obtained for studied populations are discussed in this paper.

  9. Assessing the mitochondrial DNA diversity of the Chagas disease vector Triatoma sordida (Hemiptera: Reduviidae)

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    Pessoa, Grasielle Caldas D‘Ávila; de Sousa, Tais Nóbrega; Sonoda, Ivan Vieira; Diotaiuti, Liléia

    2016-01-01

    Triatoma sordida is a species that transmits Trypanosoma cruzi to humans. In Brazil, T. sordida currently deserves special attention because of its wide distribution, tendency to invade domestic environments and vectorial competence. For the planning and execution of control protocols to be effective against Triatominae, they must consider its population structure. In this context, this study aimed to characterise the genetic variability of T. sordida populations collected in areas with persistent infestations from Minas Gerais, Brazil. Levels of genetic variation and population structure were determined in peridomestic T. sordida by sequencing a polymorphic region of the mitochondrial cytochrome b gene. Low nucleotide and haplotype diversity were observed for all 14 sampled areas; π values ranged from 0.002-0.006. Most obtained haplotypes occurred at low frequencies, and some were exclusive to only one of the studied populations. Interpopulation genetic diversity analysis revealed strong genetic structuring. Furthermore, the genetic variability of Brazilian populations is small compared to that of Argentinean and Bolivian specimens. The possible factors related to the reduced genetic variability and strong genetic structuring obtained for studied populations are discussed in this paper. PMID:27143491

  10. Quantification of the genetic change in the transition of Rhodnius pallescens Barber, 1932 (Hemiptera: Reduviidae from field to laboratory

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    Leysa Jackeline Gómez-Sucerquia

    2009-09-01

    Full Text Available Previous studies have reported genetic differences between wild-caught sylvatic, domestic and laboratory pop-ulations of several Triatominae species. The differences between sylvatic and laboratory colonies parallel are similar to the differences observed between sylvatic and domestic populations. Laboratory colonies are frequently used as references for field populations, but the consequences of founder events on the genetic makeup of laboratory or domestic populations are rarely quantified. Our goal was to quantify the genetic change in Rhodnius pallescens populations artificially submitted to founder effects via laboratory colonization. We compared the genetic makeup of two sylvatic populations and their laboratory descendants using a panel of 10 microsatellite markers. Both sylvatic populations were initially collected from palm trees, but the colonies differed in the number of founder insects and amount of time kept in the laboratory. We evaluated allelic polymorphism, differences between expected and observed heterozygosity, estimates of population differentiation (Fst and inbreeding (Fis, Fit and cluster analyses based on Nei's distances. We found a unique genetic structure for each sample population, with significant differentiation between the field insects and each of the laboratory generations. These analyses showed strong founder effects and showed that genetic drift had led to a genetic equilibrium over several generations of isolation. Our results suggest that laboratory colonies of R. pallescens have a different genetic structure than their wild relatives and similar processes likely affect other Triatominae laboratory stocks.

  11. Development and glycoprotein composition of the perimicrovillar membrane in Triatoma (Meccus) pallidipennis (Hemiptera: Reduviidae).

    Science.gov (United States)

    Gutiérrez-Cabrera, Ana E; Alejandre-Aguilar, Ricardo; Hernández-Martínez, Salvador; Espinoza, Bertha

    2014-11-01

    Hemipterans and thysanopterans (Paneoptera: Condylognatha) differ from other insects by having an intestinal perimicrovillar membrane (PMM) which extends from the base of the microvilli to the intestinal lumen. The development and composition of the PMM in hematophagous Reduviidae depend on factors related to diet. The PMM may also allow the human parasite Trypanosoma cruzi, the etiological agent of human Chagas Disease, to establish and develop in this insect vector. We studied the PMM development in the Mexican vector of Chagas Disease, Triatoma (Meccus) pallidipennis. We describe changes in the midgut epithelial cells of insects in response to starvation, and at different times (10, 15 and 20 days) after bloodfeeding. In starved insects, the midguts showed epithelial cells closely connected to each other but apparently free of PMM with some regions being periodic acid-Schiff (PAS-Schiff) positive. In contrast, the PMM was evident and fully developed in the midgut region of insects 15 days after feeding. After this time, the PMM completely covered the microvilli and reached the midgut lumen. At 15 days following feeding the labeled PAS-Schiff increased in the epithelial apex, suggesting an increase in carbohydrates. Lectins as histochemical reagents show the presence of a variety of glycoconjugates including mannose, glucose, galactosamine, N-acetyl-galactosamine. Also present were N-acetyl-glucosamine and sialic acid which contribute to the successful establishment and replication or T. cruzi in its insect vectors. By means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the formation and structure of the PMM is confirmed at 15 days post feeding. Our results confirmed the importance of the feeding processes in the formation of the PMM and showed the nature of the biochemical composition of the vectors' intestine in this important Mexican vector of Chagas disease. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Impacts of 2 species of predatory Reduviidae on bagworms in oil palm plantations.

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    Jamian, Syari; Norhisham, Ahmad; Ghazali, Amal; Zakaria, Azlina; Azhar, Badrul

    2017-04-01

    Integrated pest management (IPM) is widely practiced in commercial oil palm agriculture. This management system is intended to minimize the number of attacks by pest insects such as bagworms on crops, as well as curb economic loss with less dependency on chemical pesticides. One practice in IPM is the use of biological control agents such as predatory insects. In this study, we assessed the response of predatory natural enemies to pest outbreak and water stress, and document the habitat associations of potential pest predators. The abundances of 2 predatory insect species, namely Sycanus dichotomus and Cosmolestes picticeps (Hemiptera: Reduviidae), were compared bagworm outbreak sites and nonoutbreak sites within oil palm plantations. We also examined habitat characteristics that influence the abundances of both predatory species. We found that the abundance of C. picticeps was significantly higher in bagworm outbreak sites than in nonoutbreak sites. There were no significant differences in the abundance of S. dichotomus among outbreak and non-outbreak sites. Both species responded negatively to water stress in oil palm plantations. Concerning the relationship between predatory insect abundance and in situ habitat quality characteristics, our models explained 46.36% of variation for C. picticeps and 23.17% of variation for S. dichotomus. Both species of predatory insects thrived from the planting of multiple beneficial plants in oil palm plantations. The results suggest that C. picticeps can be used as a biological agent to control bagworm populations in oil palm plantations, but S. dichotomus has no or little potential for such ecosystem service. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  13. Aspectos del comportamiento de los triatominos (Hemiptera: Reduviidae, vectores de la enfermedad de Chagas

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    Diana Castillo

    2000-03-01

    Full Text Available Se presenta una revisión actualizada sobre los triatominos, vectores de la enfermedad de Chagas, en aspectos como la ubicación taxonómica de las especies actualmente reconocidas, asi como de las especies encontradas en los domicilios en Colombia y del ciclo de vida del grupo en general, todo lo cual involucra el tamaño de las poblaciones, su dispersión y situaciones antrópicas que las están llevando a procesos de domiciliación. Igualmente, se hace un llamado de atención sobre las consecuencias epidemiológicas que pueden derivarse de dichas alteraciones. En Colombia, el Trypanosoma cruziafecta el 3,3% de la población y, aproximadamente, el 10% se encuentra en riesgo de adquirir la infección. En esta parasitosis intervienen tres componentes biológicos: el protozoo T.cruzi, el vector triatomino Reduviidae y el reservorio vertebrado. Debido a la alteración de los ecótopos naturales a la acción devastadora de la tala de bosques, a la construcción de viviendas con hojas de palmas y a la cacería indiscriminada de animales silvestres, entre otros, la conducta de los triatominos, insectos originalmente silvestres, ha sufrido cambios con el resultado de invasiones esporádicas o permanentes a las viviendas, lo cual está originando un cambio sustancial del comportamiento de la triada vector-huésped-parásito y, consecuentemente. de la enfermedad.

  14. Chromosomal variation, macroevolution and possible parapatric speciation in Mepraia spinolai (Porter (Hemiptera: Reduviidae

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    Frias Daniel

    1998-01-01

    Full Text Available Mepraia spinolai is an endemic species in Chile that lives in wild and domestic habitats. It is the only species of the Reduviidae family that shows alate polymorphism; females are always wingless, but males can be found with and without wings. The M. spinolai karyotype consists of 10 pairs of autosomes and a complex sex determination system. Males from the northernmost regions I and II (latitude 18°-26° South are always winged (braquipterous and are X1X2Y, with a large Y chromosome. From region III to the metropolitan region (latitude 26°-33° South, males may be either winged or wingless but appear to be polymorphic for a small neo-Y chromosome, which may have originated by fracture of the large holocentric Y chromosome found in populations from farther north. Experimental crosses suggest that the genes for wings are linked in the Y chromosome and also that there are two cytologically indistinguishable types of neo-Y chromosomes. One form (Y1 bears a gene or genes for wings while the other (Y2 lacks such genes. Males that are X1X2Y1, X1X2Y1Y1 and X1X2Y1Y2 are winged, while the absence of Y1 (X1X2Y2 and X1X2Y2Y2 results in a wingless male. These chromosomes and morphological changes are correlated with a shift of the southern population into more arid habitats of the interior in the metropolitan region and region III.

  15. [Morphological and histological study of eggs of six species of the Triatoma genus (Hemiptera: Reduviidae)].

    Science.gov (United States)

    Obara, Marcos T; da Rosa, João A; da Silva, Nilza N; Ceretti, Walter; Urbinatti, Paulo R; Barata, José M S; Jurberg, José; Galvão, Cleber

    2007-01-01

    The objective of this study was to analyze the morphological and histological characteristics of eggs from six triatomine species in order to obtain a generic and specific characterization of this group of Trypanosoma cruzi vectors and better understand their phylogenetic and taxonomic aspects. The eggs of the respective species came from the collection of the Laboratório de Triatomíneos e Culicídeos da Faculdade de Saúde Pública/USP, from the Insetário do Serviço Especial de Saúde de Araraquara - SESA and from the Triatomine insectary of the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos (FIOCRUZ), in Rio de Janeiro. Morphological studies were done with optical microscopy and scanning electron microscopy. Histological analyses used only optical microscopy. All of the species analyzed showed a predominance of hexagonal cells. The exchorion of Triatoma breyeri Del Ponte, T. costalimai Verano Galvão, and T. tibiamaculata (Pinto) consists of unornamented cells, overlapping or slightly separated, with a smooth, padded appearance. Meanwhile, in T. matogrossensis Leite Barbosa, T. sherlocki Papa, Juberg, Carcavallo, Cerqueira Barata, and T. williami Galvão, Souza Lima, the exchorion cells are ornamented on their entire surface with perforations and fissures. Egg histology showed undulations, pores, and orifices. The study helps to expand the generic and specific knowledge of the Triatominae subfamily. The characteristics identified in the exchorion of the eggshells can help separate close species. These new parameters will back the elaboration of future dichotomous keys, help to determine each vector species role and expand knowledge of the various species.

  16. Susceptibility of Triatoma sordida Stal, 1859 (Hemiptera: Reduviidae to alpha-cypermethrin under natural climatic conditions

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    Grasielle Caldas DÁvila Pessoa

    2015-08-01

    Full Text Available Abstract:INTRODUCTION:Despite the recommendations by interpretation of resistance ratios obtained in laboratory bioassays, little is known about the actual impact of these results in the effectiveness of vector control activities in the field. In this context, our objective was to determine the mean value of different resistance ratios obtained by laboratory bioassays performed as part of the chemical control strategies of Triatoma sordida in the field.METHODS:Field bioassays were developed in Monte Azul and Coração de Jesus (Southeast, Brazil. In each location, samples were formed with three domestic units treated with alpha-cypermethrin 20.0% (Alfatek (r 200 SC. One day after spraying, 10 fifth-instar nymphs remained in contact with the surfaces treated (adobe with plaster, adobe without plaster, or wood with insecticide in plastic cones for 72h. Three cones were exposed inside the intradomicile and the peridomicile. The insects in the control group were exposed to an insecticide-free piece of cardboard. Mortality was measured 72h after removal of the insects from the treated surfaces. The tests were realized in triplicate.RESULTS:Mortality was 100.0% in all locations, except for Monte Azul; Landinho (96.6% and Coração de Jesus; Barriguda (96.6%.CONCLUSIONS:Although the resistant populations in laboratory tests proved to be susceptible in the field, this observation is not sufficient to suggest that the cut-off points used to justify the resistance ratio should be changed. In this sense, we recommend that laboratory and field bioassays are carried out with a greater number of Triatominae populations to allow more in-depth consideration of the subject.

  17. Miridae, Reduviidae and Lygaeoidea (Hemiptera collected in Colonia Carlos Pellegrini (Iberá watershed, Corrientes, Argentina Reduviidae, Miridae y Lygaeoidea (Hemiptera recolectados en Colonia Carlos Pellegrini (Esteros de Iberá, Corrientes, Argentina

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    María C. Melo

    2004-07-01

    Full Text Available With the intention of contributing to the knowledge of the biodiversity in the protected areas of Argentina, terrestrial Heteroptera were collected in the Natural Reserve of the Iberá. The sampling site was the locality of Colonia Carlos Pellegrini (28° 32'S 57° 09'W and the following collection methods were used: sweeping, beating, fogging and light-trapping. A list is presented, with 90 species belonging to the superfamilies Reduvioidea (Reduviidae, Mirioidea (Miridae, and Lygaeoidea (Berytidae, Colobathristidae, Cymidae, Lygaeidae, Blissidae, Geocoridae, Pachygrontidae and Rhyparochromidae, 13 of them are new records for the Argentine Republic (Debilia fusciventris, Sindala granuligera, Pnirontis (Centromelus tabida, Cymoninus notabilis, Ochrimnus (Phaeochrimnus limbatipennis, Oncopeltus luctuosus, Ischnodemus gayi, Oedancala nana, Cistalia signoretii, Paracholula picta, Cholula lympha, Cholula maculatus, Pseudopachybrachius vinctus and 36 new records for the province of Corrientes.Con el objeto de contribuir al conocimiento de la biodiversidad en las áreas protegidas de la Argentina, se realizaron recoleccciones de Heteroptera terrestres en la Reserva Natural del Iberá. El sitio de muestreo fue la localidad de Colonia Carlos Pellegrini (28° 32'S 57°09'W y se utilizaron los siguientes métodos de recoleccion: rastreo, golpeteo, fogging y trampa de luz. Se presenta una lista con 90 especies pertenecientes a las superfamilias Reduvioidea (Reduviidae, Mirioidea (Miridae y Lygaeoidea (Berytidae, Colobathristidae, Cymidae, Lygaeidae, Blissidae, Geocoridae, Pachygrontidae y Rhyparochromidae, de las cuales 13 representan primeras citas para la República Argentina (Debilia fusciventris, Sindala granuligera, Pnirontis (Centromelus tabida, Cymoninus notabilis, Ochrimnus (Phaeochrimnus limbatipennis , Oncopeltus luctuosus , Ischnodemus gayi , Oedancala nana , Cistalia signoretii, Paracholula picta, Cholula lympha, Cholula maculatus

  18. Blood Meal Source Characterization Using Illumina Sequencing in the Chagas Disease Vector Rhodnius pallescens (Hemiptera: Reduviidae) in Panamá.

    Science.gov (United States)

    Kieran, Troy J; Gottdenker, Nicole L; Varian, Christina P; Saldaña, Azael; Means, Nicolas; Owens, Darlisha; Calzada, Jose E; Glenn, Travis C

    2017-11-07

    Accurate blood meal identification is critical to understand hematophagous vector-host relationships. This study describes a customizable Next-Generation Sequencing (NGS) approach to identify blood meals from Rhodnius pallescens (Hemiptera: Reduviidae) triatomines using multiple barcoded primers and existing software to pick operational taxonomic units and match sequences for blood meal identification. We precisely identified all positive control samples using this method and further examined 74 wild-caught R. pallescens samples. With this novel blood meal identification method, we detected 13 vertebrate species in the blood meals, as well as single and multiple blood meals in individual bugs. Our results demonstrate the reliability and descriptive uses of our method. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  19. New arrangements on several species subcomplexes of Triatoma genus based on the chromosomal position of ribosomal genes (Hemiptera - Triatominae).

    Science.gov (United States)

    Pita, Sebastián; Lorite, Pedro; Nattero, Julieta; Galvão, Cleber; Alevi, Kaio C C; Teves, Simone C; Azeredo-Oliveira, Maria T V; Panzera, Francisco

    2016-09-01

    The hemipteran subfamily Triatominae includes 150 blood-sucking species, vectors of Chagas disease. By far the most specious genus is Triatoma, assembled in groups, complexes and subcomplexes based on morphological similarities, geographic distribution and genetic data. However, many molecular studies questioned the species integration of several subcomplexes as monophyletic units. In triatomines, chromosomal position of major ribosomal DNA (rDNA) loci is extremely variable but seems to be species-specific and an evolutionary conserved genetic trait, so that closely related species tend to have ribosomal clusters in the same chromosomal location. Considering that the autosomal position as the ancestral character for all heteropteran species, including triatomines, we suggest that the movement of rDNA loci from autosomes to sex chromosomes rapidly established reproductive barriers between divergent lineages. We proposed that the rDNA translocation from the autosomes to the sex chromosomes restrict reproductive compatibility and eventually promote speciation processes. We analyzed the chromosomal position of 45S rDNA clusters in almost all species of the matogrossensis, rubrovaria, maculata and sordida subcomplexes. The fluorescent in situ hybridization results are discussed considering the available genetic data and we proposed new arrangements in the species that constitute each one of these subcomplexes. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Perfil alimentario de Triatoma rubrovaria (Blanchard, 1843 (Hemiptera, Triatominae en ámbitos peridomiciliarios, de una localidad rural de Uruguay Feeding patterns of Triatoma rubrovaria (Blanchard, 1843 (Hemiptera, Triatominae in peridomestic habitats, in a rural area of Uruguay

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    Roberto Salvatella

    1994-08-01

    Full Text Available En una localidad con población rural dispersa ("La Bolsa", 3ª seccional, dpto. de Artigas, Uruguay se estudió, en ámbitos peridomiciliarios, el perfil alimentario de T. rubrovaria (triatomíneo silvestre y potencial vector secundario de colonización intradomiciliaria, utilizándose la técnica de doble difusión en agar, enfrentando contenido promesentérico frente a un panel de 13 sueros. Se pudo detectar en 120 insectos 251 identificaciones de fuente hematofágica con alimentación predominante en mamíferos (73%, pero marcado eclectismo alimentario (mamíferos, aves, reptiles y cucarachas, incluyendo hematofagia sobre seres humanos en un 8% de las identificaciones totales. La micropredación de hemolinfa lo ubicaría en una situación evolutiva primitiva, intermedia entre predator/entomófago y triatomineo/hematófago, que comparte con T. circunmaculata. Los mamíferos detectados con mayor frecuencia fueron dasipódidos y bóvidos, aunque la fuente hematofágica, salvo en los adultos alados, se constituye en un fenómeno de proximidad ocasional por cohabitación de un mismo habitat. La frecuencia de alimentación sobre hombre, hallada en un ambiente peridomiciliario, aporta un importante elemento a su capacidad vectorial potencial. En el análisis espacial de las dietas se muestra al peridomicilio como un área de interacción de hospederos domésticos, silvestres y sinantrópicos. La infección tripanosómica fue mínima comparada con las altas tasas de infección de ámbitos silvestres.It has been studied the feeding patterns of Triatoma rubrovaria (wild triatominae bug, and intradomiciliary secondary vector of T. cruzi in a rural area of "La Bolsa" (Department of Artigas. Agar double diffusion test were used for analyze the blood meal, from 120 insects, which were confronted to 13 antisera. It has 251 identify blood meals, and the most frequently was mamalian host (73%, but it has a variable source of feeding (mammals, birds, reptils

  1. Mitochondrial Gene Confirms the Specific Status of Triatoma pintodiasi Jurberg, Cunha, and Rocha, 2013 (Hemiptera, Triatominae), an Endemic Species in Brazil.

    Science.gov (United States)

    Alevi, Kaio Cesar Chaboli; Guerra, Ana Letícia; Imperador, Carlos Henrique Lima; Jurberg, José; Moreira, Felipe Ferraz Figueiredo; Oliveira, Maria Tercília Vilela de Azeredo

    2017-01-11

    Chagas disease is most frequently transmitted to humans through contact with feces of insects from the Triatominae subfamily. In Brazil, there are 65 species of triatomines distributed throughout the country's 27 states. Among the species in the state of Rio Grande do Sul, Triatoma rubrovaria, Triatoma oliveirai, Triatoma pintodiasi, Triatoma klugi, Triatoma carcavalloi, and Triatoma circummaculata (with the addition Triatoma limai, which is endemic to Argentina) form the T. rubrovaria subcomplex. The last species described and grouped into this subcomplex was T. pintodiasi Thus, this study characterized the genetic distance between T. pintodiasi and of the other members of the T. rubrovaria subcomplex to evaluate the specific status of T. pintodiasi The genetic distance observed between T. pintodiasi and the other species of the T. rubrovaria subcomplex was large, a finding which highlights the specific status of the species considered to be cryptic of T. circummaculata. © The American Society of Tropical Medicine and Hygiene.

  2. [Distribution and ecoepidemiology of the triatomine fauna (Hemiptera: Reduviidae) in Margarita Island, Bolívar, Colombia].

    Science.gov (United States)

    Cantillo-Barraza, Omar; Gómez-Palacio, Andrés; Salazar, Diego; Mejía-Jaramillo, Ana María; Calle, Jaime; Triana, Omar

    2010-01-01

    Information concerning to triatomine diversity and some eco-epidemiologic aspects on Margarita Island has been recorded only from two of the five counties on the island. Knowledge about species habitat and their natural infection is essential to establish the risk for Chagas disease in endemic areas. The distribution of triatomine insect fauna and its infection with Trypanosoma cruzi was described in order to establish and to stratify the risk of Chagas disease transmission. Each of the 5 counties on Margarita Island were surveyed for triatomid insects inside and outside each dwelling. In the extradomicilary area, searches were conducted in the palms and bird nests located within forests and in pastures near domiciles. Infection with T. cruzi was determined amplifying by PCR the DNA extracted from triatomine feces. Five species of Reduviidae were recovered among the 1,154 triatomines captured in the 5 counties. Triatoma maculata and Rhodnius pallescens showed high infection rates within dwellings and as well as in the peridomestic areas in Mompós and Talaigua Nuevo. On the palm trees, only R. pallescens and Eratyrus cuspidatus were found infected, and only in San Fernando and Margarita. In Cicuco, only R. pallescens was infected. Presence of Triatoma dimidiata was also ascertained. Infected triatomines were present in houses and on palm trees in all counties on the island. These observations indicate a potential risk of Chagas across the entire island; furthermore the presence of T. dimidiata, a very efficient Chagas vector, emphasizes the need to establish its epidemiological status on the island.

  3. Variacion estacional de una población silvestre de Rhodnius Pallescens Barber 1932 (Heteroptera: triatominae en la costa caribe colombiana

    Directory of Open Access Journals (Sweden)

    1998-01-01

    Full Text Available VARIATION SAISONNIERE D’UNE POPULATION SAUVAGE DE RHODNIUS PALLESCENS BARBER, 1932 (HETEROPTERA:TRIATOMINAE SUR LA COTE CARAÏBE COLOMBIENNE. Dans le cadre du programme franco-colombien “Écologie des triatomes sauvages (Triatominae du département de Sucre (Colombie et évaluation de l’efficacité d’une biopréparation insecticide à partir du champignon entomopathogène Beauveria bassiana (Hyphomycetes” (1994-1996, les auteurs ont étudié la dynamique de population de l’insecte hématophage Rhodnius pallescens dans une palmeraie de l’espèce Attalea butyracea (Arecaceae dans le municipio (cf. nota 1 de San Onofre (côte caraïbe colombienne. Au cours de la saison sèche et de la saison des pluies, un total de 71 palmiers ont été disséqués et 1 356 insectes capturés (163 adultes et 1 196 individus de tous les stades larvaires. 86% des palmiers étaient infestés (83% pendant la saison sèche et 91% pendant la saison des pluies la moyenne d’insectes retrouvés par palmier était de 19,5 (23,6 lors de la saison sèche et 17,6 pendant la saison des pluies. L’analyse des données permet de conclure que l'élément saison n’influe pas sur les variations des densités des insectes mais agit sur les compositions d’âge des populations de R. pallescens et que, même si l’évaluation du bioinsecticide peut se faire pendant toute l’année, il est recommandé de l’effectuer en novembre, au début de la saison des pluies. En el marco del programa colombo-francés “Ecología de triatominos silvestres (Triatominae del Departamento de Sucre (Colombia y evaluación de la eficacia de una biopreparación insecticida en base al hongo entomopatógeno Beauveria bassiana (Hyphomycetes” (1994-1996, los autores estudiaron la dinámica poblacional del insecto hematófago Rhodnius pallescens en un palmeral de la especie Attalea butyracea (Arecaceae en el municipio (1 de San Onofre (costa caribe colombiana. Se realizaron un total de 71 disecciones

  4. A Microsatellite-Based Analysis of House Infestation With Triatoma Infestans (Hemiptera: Reduviidae) After Insecticide Spraying in the Argentine Chaco.

    Science.gov (United States)

    Piccinali, Romina V; Gaunt, Michael W; Gürtler, Ricardo E

    2018-01-27

    Prevention of vector-borne transmission of Chagas disease mainly relies on residual insecticide spraying. Despite significant success at a regional scale, house infestation with Triatoma infestans (Klug) (Hemiptera: Reduviidae) still persists in the Gran Chaco ecoregion. One key aspect is the identification of the sources of reinfestant triatomines. After detecting fine-scale genetic structure in two rural villages of Pampa del Indio, Argentine Chaco, we tested hypotheses on the putative origins of the triatomines collected at 4, 8, and 12 mo after insecticide house spraying. We genotyped 10 microsatellite loci in 262 baseline and 83 postspraying triatomines from different houses. Genetic variability was similar between baseline and postspraying populations, but 13 low-frequency alleles were not detected at postspraying. FSTs were not significant between insects collected before and after insecticide spraying at the same house in all but one case, and they clustered together in a neighbor-joining tree. A clustering algorithm detected seven genetic groups, four of them mainly composed of baseline and postspraying insects from the same house. Assignment tests suggested multiple putative sources (including the house of collection) for most postspraying insects but excluded a house located more than 9 km from the study area. The origin of three triatomines was attributed to immigration from other unaccounted sources. Our study is compatible with the hypothesis that house reinfestations in the Argentine Chaco are mostly related to residual foci (i.e., survival of insects within the same community), in agreement with field observations, spatial analysis, and morphometric studies previously published. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Male meiosis, heterochromatin characterization and chromosomal location of rDNA in Microtomus lunifer (Berg, 1900 (Hemiptera: Reduviidae: Hammacerinae

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    María Poggio

    2011-05-01

    Full Text Available In the present work, we analysed the male meiosis, the content and distribution of heterochromatin and the number and location of nucleolus organizing regions in Microtomus lunifer (Berg, 1900 by means of standard technique, C- and fluorescent bandings, and fluorescent in situ hybridization with an 18S rDNA probe. This species is the second one cytogenetically analysed within the Hammacerinae. Its male diploid chromosome number is 31 (2n=28+X1X2Y, including a minute pair of m-chromosomes. The diploid autosomal number and the presence of m-chromosomes are similar to those reported in M. conspicillaris (Drury, 1782 (2n=28+XY. However, M. lunifer has a multiple sex chromosome system X1X2Y (male that could have originated by fragmentation of the ancestral X chromosome. Taking into account that M. conspicillaris and M. lunifer are the only two species within Reduviidae that possess m-chromosomes, the presence of this pair could be a synapomorphy for the species of this genus. C- and fluorescent bandings showed that the amount of heterochromatin in M. lunifer was small, and only a small CMA3 bright band was observed in the largest autosomal pair at one terminal region. FISH with the 18S rDNA probe demonstrated that ribosomal genes were terminally placed on the largest autosomal pair. Our present results led us to propose that the location of rDNA genes could be associated with variants  of the sex chromosome systems in relation with a kind of the sex chromosome systems within this family. Furthermore, the terminal location of NOR in the largest autosomal pair allowed us to use it as a chromosome marker and, thus, to infer that the kinetic activity of both ends is not a random process, and there is an inversion of this activity.

  6. Preliminary Observations on Zelus obscuridorsis (Stål (Hemiptera: Reduviidae as Predator of the Corn Leafhopper (Hemiptera: Cicadellidae in Argentina

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    Eduardo G. Virla

    2015-06-01

    Full Text Available The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae, is an important corn pest in most of tropical and subtropical America. This leafhopper has a rich natural enemy complex of which parasitoids and pathogens are the most studied; knowledge on its predators is limited. We noted the presence of the native assassin bug Zelus obscuridorsis (Hemiptera: Reduviidae predating diverse motile insects, including the corn leafhopper, on corn plants cultivated in household vegetable gardens in San Miguel de Tucumán (Argentina; in order to verify its predatory actions, we exposed lab-bred individuals of D. maidis to adults of Z. obscuridorsis. The predators were starved for 24 h before trials in which the corn leafhopper in different developmental stages were exposed. Zelus obscuridorsis is highly skilled in catching specimens in motion, but it was not able to prey on eggs. The predator was capable to catch and prey on nymphs and adults.

  7. Less invasive blood sampling in the animal laboratory: clinical chemistry and haematology of blood obtained by the Triatominae bug Dipetalogaster maximus.

    Science.gov (United States)

    Markvardsen, S N; Kjelgaard-Hansen, M; Ritz, C; Sørensen, D B

    2012-04-01

    Dipetalogaster maximus (Dipmax), a blood-sucking bug belonging to the family Reduviidae, has been used to obtain blood samples, for example for clinical chemistry and haematology, in a variety of zoo animals and wildlife. Using this bug allows stress-free blood sampling as the bug is able to draw blood without the mammal noticing the bug. In laboratory animal science, the need for blood samples from unstressed animals may arise, especially in animal behaviour research. The use of Dipmax bugs may prove a valuable tool for this purpose. To validate the method, we compared an array of standard blood parameters sampled from New Zealand White rabbits, sampled either by the use of bugs or by the conventional method; puncture of vena auricularis caudalis. The overall hypothesis was that there was no significant difference in clinical chemistry and haematological parameters between the bug method and the conventional method. A total of 17 clinical parameters as well as 12 haematological parameters were measured and compared in New Zealand White rabbits. The results showed that for 13 of these 29 analysed parameters, the bug method and the conventional method did not give significantly different results, and the obtained results were thus directly comparable. For the remaining parameters the obtained results were significantly different. However, all parameters were measurable in the bug samples. The influences of the bug metabolism on these parameters are discussed.

  8. A taxonomic monograph of the assassin bug genus Zelus Fabricius (Hemiptera: Reduviidae): 71 species based on 10,000 specimens

    Science.gov (United States)

    Hart, Elwood R; Weirauch, Christiane

    2016-01-01

    Abstract The New World assassin bug genus Zelus Fabricius, 1803 (Insecta: Hemiptera: Heteroptera: Reduviidae: Harpactorinae: Harpactorini) is revised based on more than 10,000 specimens. Seventy-one species are recognized and twenty-four described as new: Zelus aithaleos sp. n., Zelus amblycephalus sp. n., Zelus antiguensis sp. n., Zelus auralanus sp. n., Zelus bahiaensis sp. n., Zelus banksi sp. n., Zelus casii sp. n., Zelus championi sp. n., Zelus cordazulus sp. n., Zelus fuliginatus sp. n., Zelus gilboventris sp. n., Zelus gracilipes sp. n., Zelus grandoculus sp. n., Zelus kartaboides sp. n., Zelus lewisi sp. n., Zelus panamensis sp. n., Zelus paracephalus sp. n., Zelus rosulentus sp. n., Zelus russulumus sp. n., Zelus spatulosus sp. n., Zelus truxali sp. n., Zelus umbraculoides sp. n., Zelus umbraculus sp. n., and Zelus xouthos sp. n. Five species, Zelus araneiformis Haviland, 1931, Zelus gradarius Bergroth, 1905, Zelus modestus (Stål, 1862), Zelus subfasciatus Stål, 1860 and Zelus vittaticeps Stål, 1866, are removed from Zelus and placed incertae sedis within Harpactorini. Nine new synonyms are recognized (senior synonym in parentheses): Zelus atripes Champion, 1898 syn. nov. (=Zelus conjungens [Stål, 1860]), Zelus dispar Fabricius, 1803 syn. nov. (=Zelus pedestris Fabricius, 1803), Zelus formosus Haviland, 1931 syn. nov. (=Zelus laticornis Herrich-Schaeffer, 1853), Zelus obscuridorsis (Stål, 1860) syn. nov. (=Zelus pedestris), Zelus pallidinervus Haviland, 1931 syn. nov. (=Zelus kartabensis Haviland, 1931), Zelus personatus Berg, 1879 syn. nov. (=Zelus versicolor Herrich-Schaeffer, 1848), Zelus trimaculatus Champion, 1898 syn. nov. (=Zelus means Fabricius, 1803), Zelus trimaculicollis (Stål, 1855) syn. nov. (=Zelus means), and Zelus tristis Haviland, 1931 syn. nov. (=Zelus laticornis). Zelus conjungens (Stål, 1860) stat. rev. Is resurrected from junior synonymy with zealous armillatus (Lepeletier & Seville, 1825). Zelus ambulans Stål, 1862 stat. rev

  9. Embryology of Triatoma infestans (KLUG, (Hemiptera, Reduviidae, a Chagas' disease vector Embriología del Triatoma infestans, vector de la enfermedad de Chagas

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    Laura E. Fichera

    1992-06-01

    Full Text Available This study reports the embryogenesis of T. infestans (Hemiptera, Reduviidae. Morphological parameters of growth sequences from oviposition until hatching (12-14 d 28ºC were established. Five periods, as percent of time of development (TD, were characterized from oviposition until hatching. The most important morphological features were: 1 formation of blastoderm within 7% of TD; 2 germ band and gastrulation within 30% of TD; 3 nerve cord, limb budding, thoracic and abdominal segmentation and formation of body cavity within 50% of TD; 4 nervous system and blastokinesis end, and development of embryonic cuticle within 65% of TD; 5 differentiation of the mouth parts, fat body, and Malphigian tubules during final stage and completion of embryo at day 12 to day 14 around hatching. These signals were chosen as appropriate morphological parameters which should enable the evaluation of embryologic modifications due to the action/s of different insecticidesEn este estudio se caracterizó el desarrollo embrionario del T. infestans (Hemiptera Reduviidae. Se establecieron parámetros morfológicos secuenciales de crecimiento desde la oviposición hasta la eclosión, (12-14 d 28ºC. Cinco períodos de crecimiento fueron determinados y expresados como fracciones porcentuales del tiempo total del desarrollo (TD hasta la eclosión. Los eventos morfológicos mas importantes fueron: 1 La formación del blastodermo hasta el 7% del TD; 2 La aparición de la banda germinativa y su gastrulación transcurridos un 30% del TD; 3 El comienzo de la formación del cordón nervioso, de las extremidades, la segmentación torácica y abdominal y la formación del mixocele cuando la embriogénesis alcanzó el 50% del TD; 4 La terminación de la blastoquinesis, el desarrollo completo del sistema nervioso y la aparición de la cutícula embrionaria hasta el 65% del TD; 5 En la etapa final de la embriogenesis se observó la diferenciación del aparato mandibular, el cuerpo graso

  10. Biology, behaviour and functional response of Cydnocoris gilvus Brum. (Heteroptera: Reduviidae: Harpactorinae a predator of Tea Mosquito Bug (Helopeltis antonii Sign. on cashew in India

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    K.K. Srikumar

    2014-06-01

    Full Text Available Helopeltis spp. (Hemiptera: Miridae are major sucking pests of cashew (Anacardium occidentale L. in India. Cydnocoris gilvus Brum. (Heteroptera: Reduviidae: Harpactorinae is recorded as a potential predator of Helopeltis spp. Biology, mating behaviour and functional response of C. gilvus were studied by rearing in the laboratory (temperature 26-28 0C; relative humidity 89-94 % with wax moth, Galleria mellonella, larvae. Based on laboratory rearing, the fecundity was 56.33 eggs in 8.67 batches per female. The average stadial period was 37.3 days, with a maximum of 11 days for V instar and a minimum of 4.5 days for III instars. C. gilvus took 45.5 days to complete a generation. The innate capacity of natural increase was 0.07 with a gross reproduction of 67.8 females per female. The adult exhibited a pin and jab mode of predation in a sequence of actions. The sequential action of mating comprised arousal (1.32 min, approach (12.30 min, riding over (140.48 min and copulation (85.40 min. The predator responded to increasing prey density by killing more prey than at lower prey densities

  11. Comparative study of enzymes in testes and ovaries from adult Dipetalogaster maximus (Uhler and Triatoma infestans (Klug (Hemiptera: Reduviidae. Correlation with fine structural organization

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    PY Scaraffia

    2009-12-01

    Full Text Available Activities of hexokinase (HK, glucose-6-phosphate dehydrogenase (G6PDH, fructose-6-phosphate kinase (F6PK, glutamate dehydrogenase (GlutDH, aspartate aminotransferase (AAT, malate dehydrogenase (MDH and glycerol-3-phosphate dehydrogenase (GPDH were determined in tissue extracts of testes and ovaries of adult Dipetalogaster maximus (Uhler and Triatoma infestans (Klug (Hemiptera: Reduviidae, insect vectors of Chagas disease. The fine structure organization of the same organs were studied by electron microscopy. Results allow the following inferences: in testes from both species, most of the glucose would be utilized through the glycolytic pathway. Amino acid catabolism for energy purposes appears to be unimportant. The number of mitochondria and the development of the rough endoplasmic reticulum in cells of the spermatogenic line indicate the occurrence of active oxidative metabolism and protein synthesis; in ovaries, levels of G6PDH indicate the existence of an active pentose pathway which would supply the NADPH required for fat and ecdysteroid synthesis. Amino acid catabolism appears to be relatively more important in ovary than in testis. Fat and glycogen are stored in follicular cells of D. maximus; oocytes of both species contain numerous fat droplets. Abundant mitocondria are present in follicular cells and oocytes. A well developed rough endoplasmic reticulum and free ribosomes are also conspicuous in these cells. The malate/aspartate H-transfer system seemed to be relatively more important than the glycerophosphate shuttle in ovaries as well in testes.

  12. Are Members of the Triatoma brasiliensis (Hemiptera, Reduviidae) Species Complex Able to Alter the Biology and Virulence of a Trypanosoma cruzi Strain?

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    Costa, J; Araújo, C A C; Freitas, C A V; Borges-Pereira, J

    2015-04-01

    Trypanosoma cruzi is the causative agent of Chagas disease, transmitted to humans and mammals by blood-sucking hemipteran insects belonging to the Triatominae subfamily. The two main genotypes of T. cruzi (TcI and TcII) differ in many characteristics concerning their genetic profile. Despite the extensive literature on vectors and the etiologic agent, several interactive aspects between these two elements of Chagas disease are still waiting to be further clarified. Here, biological and histological features resulting from the interaction between Albino Swiss mice and T. cruzi isolate PB913 after passages through vectors of the Triatoma brasiliensis species complex were evaluated. Comparing the four members of the T. brasiliensis species complex-Triatoma brasiliensis brasiliensis Neiva, Triatoma brasiliensis macromelasoma Galvão, Triatoma melanica Neiva & Lent, and Triatoma juazeirensis Costa & Felix-no significant differences in parasitemia of the infected mice were observed. At 20 days post-infection, the highest number of parasites was observed in the group of mice that were infected with parasites obtained from T. b. macromelasoma. Tropism of the parasites to different organs such as heart, bladder, and skeletal muscles followed by inflammatory cell infiltrates was observed with quantitative and qualitative differences. Even though the four members of the T. brasiliensis species complex differ in their geographical distribution, morphology, biology, ecology, and genetics, no significant influence on the parasitemia of the T. cruzi PB913 isolate was detected. After evaluation of the tissue samples, a higher pathogenicity of parasites obtained from T. b. brasiliensis was noticeable.

  13. Triatominae et Cactaceae : un risque pour la transmission de la Trypanosomose américaine dans le péridomicile (nord-est du Brésil

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    Emperaire L.

    2006-06-01

    Full Text Available Les observations de terrain réalisées dans le nord-est du Brésil ont montré la fréquente association, dans l’espace péridomiciliaire, entre un cactus, le Cereus jamacaru, la présence de nids dans ses branches et celle de Rhodnius neglectus et de Triatoma pseudomaculata, espèces vectrices du parasite Trypanosoma cruzi, agent de la maladie de Chagas. L’analyse des variables architecturales de cette Cactaceae montre que la présence de nids, et donc d’insectes, est inféodée aux pratiques traditionnelles de gestion de ce cactus. Cette étude souligne l’intérêt d’une approche intégrée de l’écologie des Triatominae pour l’identification des variables indicatrices de risque.

  14. Distribution of Zelus longipes (Hemiptera: Reduviidae) in south Florida corn fields and its functional response to corn-infesting picture-winged flies (Diptera: Ulidiidae).

    Science.gov (United States)

    Kalsi, M; Seal, D R; Nuessly, G S; Capinera, J L; Martin, C G

    2014-10-01

    The milkweed assassin bug, Zelus longipes (L.) (Hemiptera: Reduviidae), is a generalist predator and a potential biological control agent of picture-winged flies (Diptera: Ulidiidae), which cause considerable economic damage to sweet corn yields in Florida. We studied the potential of Z. longipes as a biocontrol agent of four ulidiid pests in corn fields: Euxesta stigmatias Loew, Euxesta eluta Loew, Euxesta annonae F., and Chaetopsis massyla Walker. Within-plant and within-field distributions of Z. longipes and ulidiids and functional responses of Z. longipes to ulidiid prey were determined. Highest numbers of Z. longipes and ulidiids in the R1, R2, and R3 corn stages were generally in the basal or middle leaves at 09:00 h EST, ears at 13:00 h EST, and top and tassel at 17:00 h EST. Hence, there seemed to be a coordinated migration of Z. longipes and ulidiids from the lowest to the highest parts of the corn plant during the day. Within the corn field, aggregated (clumped) distributions were most common for Z. longipes and ulidiids especially in the later R2 and R3 stages based on Taylor's power law, Iwao's patchiness regression, index of dispersion, and Lloyd's patchiness indices of dispersion. However, predator and prey populations were lower in the R1 stage, and there were inconsistent results for dispersion indices among times of day and between predators and prey. Ulidiid distributions in R1 were mostly regular (uniform) at 13:00 h EST, but aggregated at 09:00 h and 17:00 h. However, Z. longipes R1 distributions were mostly aggregated at 13:00 h, but random or regular at 09:00 h and 17:00 h EST. Handling times for male and female Z. longipes were 1.0-1.39 h and 0.67-0.97 h, respectively, and each had a type II functional response to E. stigmatias, E. eluta, and E. annonae and consumed about five flies per day. Although the population abundance of Z. longipes can vary between seasons, it appears to be a promising biocontrol agent of ulidiid flies in corn.

  15. The Evolutionary Origin of Diversity in Chagas Disease Vectors.

    Science.gov (United States)

    Justi, Silvia A; Galvão, Cleber

    2017-01-01

    Chagas disease is amongst the ten most important neglected tropical diseases but knowledge on the diversification of its vectors, Triatominae (Hemiptera: Reduviidae), is very scarce. Most Triatominae species occur in the Americas, and are all considered potential vectors. Despite its amazing ecological vignette, there are remarkably few evolutionary studies of the whole subfamily, and only one genome sequence has been published. The young age of the subfamily, coupled with the high number of independent lineages, are intriguing, yet the lack of genome-wide data makes it a challenge to infer the phylogenetic relationships within Triatominae. Here we synthesize what is known, and suggest the next steps towards a better understanding of how this important group of disease vectors came to be. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Efecto de la alternación de fuentes sanguíneas sobre la fecundidad y la fertilidad de Rhodnius prolixus Stal (Heteroptera: Reduviidae

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    Elis José Aldana

    2009-04-01

    Full Text Available En este trabajo se evidencia que si el éxito reproductivo de Rhodnius prolixus Stal está relacionado a la fuente alimentaria, entonces las necesidades biológicas del insecto son satisfechas en modos diferentes según el tipo de alternancia entre dichas fuentes de alimentación; tales diferencias son reveladas mediante los cambios en fertilidad y fecundidad del insecto. Se realizaron nueve alternancias, en cada una se suministraron dos alimentaciones, en unas se alternó la fuente de alimentación y en los controles se suministraron dos alimentaciones con la misma fuente. Las fuentes alimentarias fueron paloma, gallina y humano, esta última mediante un aparato de alimentación artificial; estas fuentes se escogieron en el supuesto que son fuentes alimentarias encontradas en los ecotopos silvestre, peri-domicilio y domicilio respectivamente. En todos los tipos de alternancia se encontró una relación lineal entre la fecundidad y el tiempo de oviposición, que la relación entre cantidad de sangre ingerida y la fecundidad varían, que la tasa de fecundidad aumenta en la segunda alimentación respecto a la primera y que la fertilidad fue superior al 95 %. Effects of alternating blood sources on fecundity and fertility of Rhodnius prolixus Stal (Heteroptera: ReduviidaeIn this work it is argued that if the reproductive parameters of Rhodnius prolixus Stal are related to the blood source upon which it feeds, then the insects biological needs must be satisfied in different ways by the alternation between blood sources, reveled through changes in the fecundity and fertility of individuals of this insect species. Nine experiments were conducted, each one consisting of two feedings, in which the blood source were either alternated or remained the same. The meal sources used were pigeon, hen and human blood, selected according to the resources found in the sylvatic, peri-domestic and domestic ecotopes respectively. It was found that the quantity of

  17. Ecology of North American Triatominae.

    Science.gov (United States)

    Ibarra-Cerdeña, Carlos N; Sánchez-Cordero, Victor; Townsend Peterson, A; Ramsey, Janine M

    2009-01-01

    In all, 40 native triatomine species and subspecies occur in NA, belonging to six genera from the Triatomini (Triatoma, Paratriatoma, Panstrongylus, Dipetalogaster, Belminus, Eratyrus), and one genus from the Rhodniini (represented by one non-native species Rhodnius prolixus, formerly occurring exclusively in domestic habitats); 28 species are found exclusively in Mexico (and/or Central America), eight are shared between the United States (US) and Mexico, and four occur exclusively in the US. The genus Triatoma is the most diverse with 26 species belonging to the species groups protracta, including the species complexes protracta and lecticularia, and rubrofasciata, which includes the species complexes rubida, phyllosoma and dimidiata. Triatomine species richness declined both at higher (south US) and lower (south of the Istmus of Tehuantepec, Mexico) latitudes. Triatoma species are found predominantly in cropland, grassland, wooded grassland and woodland landscapes. Land cover types were most similar among the lecticularia, protracta, and rubida complexes, in contrast to the phyllosoma and dimidiata species complexes. The land cover types having highest suitability for most species were wooded grassland, followed by woodland for the phyllosoma and dimidiata species complexes, and open and closed shrubland and cropland for the remaining three species complexes. A principal component analysis was used to demonstrate differences in the potential range for use of environmental conditions: protracta and phyllosoma complexes occupy the broadest niches. The present study represents a primary stratification of potential triatomine dispersal areas, based on species and species complexes, and based on predicted niche, a method which has already proven to be highly significant epidemiologically.

  18. Experiências sôbre a transmissão do Trypanosoma cruzi por sanguessugas e de tripanosomas de vertebrados de sangue frio por triatomíneos Experiments of the transmission of Trypanosoma cruzi by leechs and cold blooded vertebrate trypanosomas by triatominae

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    Samuel B. Pessôa

    1969-06-01

    Full Text Available Observou-se que o Trypanosoma cruzi não se multiplica na sanguessuga (Haementeria lutzi Pinto; os tripanosomas sugados degeneram após algum tempo; outros permanecem aparentemente normais, porém 48 horas após a ingestão infectante acabam morrendo. Observou-se ainda que os tripanosomas parasitas da rã (T. rotatorium e T. leptodactyli bem como o T. hogei, parasita da serpente Rachidelus brazili, não se multiplicam no intestino dos triatomíneos. O mais resistente (o T. leptodactyli, permanece vivo até 72 horas após a ingestão infectante, porém as outras duas espécies (T. rotatorium e T. hogei não resistem mais de 24 horas após serem sugadas pelos triatomíneos.Trypanosoma cruzi does not reproduce itself in the leech (Haementerm lutzi Pinto; the ingested trypanosomes degenerate after some time; other organisms remain apparently normal, however dying 48 hours after the feeding of the leechs. The parasite trypanosomas of the frog (T. rotatorium and T. leptodactyli as well as those parasiting the ophidian Rachidelus brazili (T. hogei do not multiply in the intestine of the triatominae. The most resistent species (T. leptocbactyli remains alive 72 hours after the feeding of the triatominae; the other two, however, do not survive more than 24 hours.

  19. Tentativas de criação de triatomíneos em laboratório por meio de alimentação "in vitro" Attempts for breeding triatominae in laboratory by means of "in vitro" feeding

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    Hertha Barbara Wüllert Telles de Souza

    1991-06-01

    Full Text Available Para simplificar a criação de triatomíneos em laboratório, necessária, por exemplo, à execução do xenodiagnóstico e em estudos de caráter biológico, foi tentada alimentação "in vitro", mediante emprego de sangue, citratado ou desfibrinado, de galinhas abatidas em matadouro avícola. Para avaliação da eficácia desse propósito, observações de duas naturezas, com Triatoma infestans, tiveram lugar, através das seguintes medidas; a análise do encadeamento de estádios ninfais sucessivos e da exeqüibilidade de satisfatórios acasalamentos, oviposição fértil e adequada reprodução; b apreciação da infectividade e da viabilidade do Trypanosoma cruzi nos insetos. Como conclusão, ficou evidente que, a despeito da facilitação operacional, o intuito não conduziu ao êxito desejado, já que o procedimento clássico, usado como controle, mostrou-se sempre superior.In order to simplify breeding of triatominae in the laboratory, for performing xenodiagnosis and other biologic studies, we tried to feed the insects "in vitro" with citrated or defibrinated blood from commercially abated chicken. Two types of efficacy observations were carried out with Triatoma infestans: a analysis of the chaining of successive nymphal stages, viability of satisfactory matching, fertile oviposition and adequate reproduction; b assessment of viability and infectivity of Trypanosoma cruzi in the insects. As a conclusion, it became evidente that, despite operational easiness, the objectives were not achieved, since the classical procedure used as the control, was always superior.

  20. Aspectos ecológicos da tripanossomíase americana: XIV - Persistência e potencial de domiciliação de populações triatomínicas silvestres em região de intensa atividade agropecuária Ecological aspects of South American tripanosomiasis: XIV - Persistence and domiciliation potential of sylvatic triatominae populations in an intensive agricultural and cattle breeding region

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    Oswaldo Paulo Forattini

    1979-06-01

    Full Text Available São apresentados os resultados de observações sobre populações triatomínicas extradomiciliares em região de intensa atividade agropecuária. Os restos de vegetação primitiva, embora reduzidos a menos de 8,0%, mostraram-se suficientes para manter essas populações. Pelo menos para Triatoma sordida, a destruição progressiva parece favorecer sua sobrevivência, graças à multiplicação de ecótopos preferidos por esse triatomíneo. Tanto essa espécie como Panstrongylus megistus e Rhodnius neglectus mostraram-se aptos à colonização em ecótopos artificiais representados por galinheiros experimentais.The results of observation of sylvatic triatominae population in a region of intensive agricultural and cattle breeding activity are reported. Important environmental changes had occurred in the area, including destruction of the primitive vegetation and intensive use of pesticides. Nevertheless, these modifications apparently did not affect the survival of Triatominae, since they were found in the remaining vegetation. Moreover, this destruction seems to have favored, to some extent, survival of Triatoma sordida by increasing the available ecotopes. This species, as well as Panstrongylus megistus and Rhodnius neglectus, showed enough ecological valence to colonize experimental fowes houses, used as artificial ecotopes.

  1. Spermiotaxonomy of the tribe Rhodniini (Hemiptera, Triatominae).

    Science.gov (United States)

    Ravazi, A; Oliveira, J; Rosa, J A; Azeredo-Oliveira, M T V; Alevi, K C C

    2016-03-24

    The tribe Rhodniini is a monophyletic group composed of 22 species, with 19 in the Rhodnius genus and three in the Psammolestes genus. These insects are morphologically very similar (cryptic species), and new tools are important for investigating the taxonomy of these vectors. Spermiotaxonomy is an important tool in differentiating between related species, and this study analyzed the spermatids of Rhodniini species to elucidate their spermiotaxonomy. All of the Rhodniini species contained two heteropyknotic filaments in the extremities of their cells. Although spermiotaxonomy has been an important tool in differentiating between species of the Triatoma genus, all of the species in the Rhodnius genus exhibited the same characteristics in their male gametes. However, spermatid analysis made it possible to confirm the monophyly of the Rhodniini tribe, because Psammolestes tertius had the same pattern as that described for Rhodnius. The results of this study demonstrate that spermiotaxonomy, in addition to being an important tool for differentiating between related species of Triatoma, can be used as an optimization tool in phylogenetic analyses.

  2. Aspectos ecológicos da tripanossomíase americana: XXI - Comportamento de espécies triatomíneas silvestres na reinfestação do intra e peridomicílio Ecological aspects of South American trypanosomiasis: XXI - Sylvatic triatominae behaviour related to the domiciliary and peridomiciliary environments

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    Oswaldo Paulo Forattini

    1984-06-01

    Full Text Available Apresentam-se os resultados obtidos com a observação da presença triatomínea em três localidades, uma delas caracterizada por estar submetida a vigilância anual ininterrupta, e duas por terem sido expurgadas respectivamente seis e um ano e meio antes. As duas primeiras situam-se em áreas de endemicidade de Panstrongylus megistus e a terceira em região endêmica para Triatoma sordida. Em todas foram levadas a efeito inspeções bimestrais destinadas a detectar a presença de triatomíneos no intra e no peridomicílio. Pôde-se confirmar o aspecto lento da domiciliação de P. megistus, em aparente contraste com o T. sordida que desenvolve intensas colônias peridomiciliares. Pelo menos em relação a esta última espécie, não parece haver diferença atrativa por parte do intra e do peridomicílio. A reinfestação do P. megistus acha-se associada freqüente com a presença de infecção natural. A reintrodução de Triatoma infestans associa-se à mobilidade da população humana. A colonização peridomiciliar de T. sordida permitiu o estudo do desenvolvimento dessas colônias, obtendo-se marcante paralelismo com os dados conseguidos em galinheiros experimentais (GE e objeto de publicações anteriores. A presença de Rhodnius neglectus nas três áreas, embora discreta, chama a atenção para seu possível potencial de domiciliação. Com este artigo encerra-se a série "Aspectos ecológicos de tripanossomíase americana".The results of observations on triatominae bugs in three localities, one of them under to active annual regular surveillance and the other two which had undergone house treatment six months and one and half years before, respectively, are reported. Two of these localities were situated in the dispersal center region of Panstrongylus megistus, and the third in the dispersal center region of Triatoma sordida. At two-monthly periods each area was submitted to dwelling inspection in the search for triatominae bugs in

  3. Sinopse dos Chryxinae (Hemiptera, Reduviidae Synopsis of the Chryxinae (Hemiptera, Reduviidae

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    Hélcio R. Gil-Santana

    2007-03-01

    Full Text Available Uma sinopse da taxonomia dos Chryxinae com chaves para os gêneros e espécies da subfamília são apresentados. Chryxus bahianus sp. nov. e o macho de Wygodzinskyella travassosi (Lent & Wygodzinsky, 1944 são descritos.Synopsis of the Chryxinae with keys to the genera and species of the subfamily are presented. Chryxus bahianus sp. nov. and the male of Wygodzinskyella travassosi (Lent & Wygodzinsky, 1944 are described.

  4. Aspectos ecológicos da tripanossomíase americana: XVII - Desenvolvimento da domiciliação triatomínea regional, em centro de endemismo de Triatoma sordida Ecological aspects of South American trypanosomiasis: XVII - The domiciliation development of local triatominae populations in the Triatoma sordida endemic center

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    Oswaldo Paulo Forattini

    1983-06-01

    mobilidade dos habitantes locais. O papel desempenhado pelo R. neglectus foi pouco expressivo embora, à semelhança de T. sordida, tenha facilmente desenvolvido colônias em galinheiros experimentais. A participação proporcional dos dois principais triatomíneos na composição específica das populações domiciliadas, observada antes e após o expurgo em cinco diferentes ocasiões, foi avaliada pelos respectivos percentuais dentro do número total e edificações (casas e anexos encontradas positivas. Os resultados mostraram aumento constante da proporção correspondente a T. sordida e diminuição da referente a T. infestans. Atribuiu-se a fatores educacionais e habitacionais maior influência sobre a domiciliação desta espécie do que na daquela. Observou-se também indícios sobre a possibilidade de dispersão ativa de T. infestans. Nas áreas rurais, os anexos peridomiciliares revelaram-se como ecótopos de concentração para o início da domiciliação de triatomíneos silvestres, em especial modo, de T. sordida. As áreas com pequeno número de anexos, aparentemente permanecem negativas por tempo mais prolongado, levando a supor que a domiciliação encontre ali maiores dificuldades de se desenvolver.The results of observations made on triatominae bug domiciliation, after house cleaning using chemical substances, are reported. The work was carried out during the period January 1975 to January 1979. The region studied is part of the endemic center formed by the "cerrados" (doy up-land forests of Central Brazil. Original local bug domiciliation found before house treatment, was composed of Triatoma infestans and Triatoma sordida populations. After desinsectization, surveillance research showed the start and development of a new, thowgh slower, domiciliation procedure, leading to house infection rates well below those initially found. After house cleaning, these values varied from 1.9 to 5.7%, comparing with 40.4% in the initial survey. This situation continued

  5. First cytogenetic study of Cavernicola pilosa Barber, 1937 (Hemiptera, Triatominae).

    Science.gov (United States)

    Souza, E S; Alevi, K C C; Ribeiro, A R; Furtado, M B; Atzingen, N C B V; Azeredo-Oliveira, M T V; Rosa, J A

    2015-10-30

    Cavernicola pilosa is a triatomine species that lives in caves and feeds on bat blood. This vector has a wide geographical distribution, and is found in Brazil, Colombia, Panama, Peru, and Venezuela. Little is known about the reproductive biology of this species, because most previous studies have only characterized its morphology, morphometry, ecology, and epidemiology. Therefore, this study aimed to obtain preliminary data related to spermatogenesis in C. pilosa by conducting cytogenetic analysis. Analysis of the heterochromatic pattern of C. pilosa during the initial prophases revealed that heterochromatic blocks are only present in the sex chromosomes. Based on the analyses of the meiotic metaphase and prophases, we found that the sex determination system of C. pilosa is XY and the chromosomes are holocentric. C. pilosa spermatids are filamentous and have long flagella. It was not possible to detect corpuscle or filament heteropycnosis in spermatids of this species. The initial cytogenetic data presented in this study are important in characterizing the spermatogenesis and heterochromatic patterns of C. pilosa. Our results suggest that adaptation to troglodytism did not result in differences in spermatogenesis in this vector.

  6. Sylvatic triatominae: a new challenge in vector control transmission.

    Science.gov (United States)

    Guhl, Felipe; Pinto, Nestor; Aguilera, Germán

    2009-07-01

    Over the last 10 years, Uruguay, Chile and Brazil have been certified as being free from disease transmission by Triatoma infestans, the main domiciliated vector for Chagas disease in the Southern Cone countries. This demonstrates that programmes addressing the vector for the disease's transmission are effective. These programmes have resulted in a dramatic decrease in the incidence of Chagas disease in Latin America. Guatemala was certified a few months ago as being free from disease transmission by Rhodnius prolixus, the main domiciliated vector for Chagas disease in Central American countries. However, the main concern for different countries' current control programmes is the continuity and sustainability of future vector control actions. The prevalence and incidence figures for individuals infected by Trypanosoma cruzi in Mexico and Andean and Central American countries highlights the need for broadened strategies in the struggle against the disease and its vectors. A number of triatomine insects are parasite vectors, each with a different life history. Therefore, it is important that new vector control strategies be proposed, keeping in mind that some species are found in peridomiciliary areas and wild ecotopes. The only viable control strategy is to reduce human interactions with vector insects so that the re-infestation and re-colonisation of human habitats will not take place.

  7. Distribution of constitutive heterochromatin in Triatoma melanocephala (Hemiptera, Triatominae).

    Science.gov (United States)

    Alevi, K C C; Rosa, J A; Azeredo-Oliveira, M T V

    2014-09-29

    In principle, Triatoma melanocephala was included in the Brasiliensis subcomplex on the basis of morphological parameters and geographical layout, since there were no other relevant data available in the literature. On the basis of karyotype, it has been proposed to exclude T. melanocephala, as well as of T. vitticeps and T. tibiamaculata, from the subcomplex, which shows fragmentation of the X sex chromosomes, thereby approaching the species of North America. Therefore, the present study aimed to determine the pattern of constitutive heterochromatin of T. melanocephala to provide new data on the cytotaxonomy of this vector of Chagas disease and especially to try to relate this species to some group, complex or subcomplex of triatomine species, aiding in their classification. This species showed no constitutive heterochromatin in the autosomes or X sex chromosome, but only the Y sex chromosome. The number of chromosomes and heterochromatin pattern of T. melanocephala proved to be identical to that described for Panstrongylus lutzi. Thus, the present study demonstrated a tentative relationship between T. melanocephala and P. lutzi. However, we emphasize that other comparative studies should be conducted between these species, such as experimental crosses and molecular, enzymatic, morphological, and morphometric analyses to determine whether these species are actually evolutionarily related or if the number of chromosomes and the heterochromatin pattern emerged as homoplasies in T. melanocephala and P. lutzi.

  8. Aggregation Behaviour and Interspecific Responses in Three Species of Triatominae

    Directory of Open Access Journals (Sweden)

    Lorenzo Figueiras Alicia N

    1998-01-01

    Full Text Available The response to intra- and interspecific assembling signals was tested in three species of Chagas' disease vectors. As previously described for Triatoma infestans, larvae of both species, T. sordida and T. guasayana, aggregated on papers impregnated with their own excrement. Moreover, bugs belonging to each of the three species also aggregated on papers contaminated with faeces from the other two, with the only exception of the larvae of T. guasayana, which did not assemble on faeces of T. sordida. In all cases, the response to interspecific excrement was as strong as that to the intraspecific one. The non-specificity of the signal is discussed in the context of the ecological association of the three species and their role as vectors of Chagas' disease

  9. Sylvatic triatominae: a new challenge in vector control transmission

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2009-07-01

    Full Text Available Over the last 10 years, Uruguay, Chile and Brazil have been certified as being free from disease transmission by Triatoma infestans, the main domiciliated vector for Chagas disease in the Southern Cone countries. This demonstrates that programmes addressing the vector for the disease's transmission are effective. These programmes have resulted in a dramatic decrease in the incidence of Chagas disease in Latin America. Guatemala was certified a few months ago as being free from disease transmission by Rhodnius prolixus, the main domiciliated vector for Chagas disease in Central American countries. However, the main concern for different countries' current control programmes is the continuity and sustainability of future vector control actions. The prevalence and incidence figures for individuals infected by Trypanosoma cruzi in Mexico and Andean and Central American countries highlights the need for broadened strategies in the struggle against the disease and its vectors. A number of triatomine insects are parasite vectors, each with a different life history. Therefore, it is important that new vector control strategies be proposed, keeping in mind that some species are found in peridomiciliary areas and wild ecotopes. The only viable control strategy is to reduce human interactions with vector insects so that the re-infestation and re-colonisation of human habitats will not take place.

  10. Hábitos alimentares, infecção natural e distribuição de triotomíneos domiciliados na região nordeste do Brasil Feeding habits, natural infection and distribution of domiciliary Triatominae bugs Northeast of Brazil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1981-04-01

    reactions to antiserums for humans, dogs, cats, rodents (Rattus, opossums (Didelphis, and birds (Gallus. By order of frequency, the species found were: Triatoma pseudomaculata (40.6%. Panstrongylus magistus (19.7%, Triatoma brasiliensis and T. sordida (14.3% each, Rhodnius nasutus (6.1% and Triatoma infestans (1.1%, and some other rare ones. Blood was detected in 42.4% and the infection rate was 3.4% of the total of the specimens examined. High feeding mobility was observed, and the general blood containing rates were 54.8% for birds and 30.0% for humans. P. megistus showed considerable anthropophily and was followed, at a lower degree, by Triatoma brasiliensis. Ornitophily was detected at high level among T. pseudomaculata and T. sordida, while R. nasutus fed almost exclusively on this host. On the other hand, the presence of human blood in specimens collected in peridomiciliar dwelling places indicates frequent spacial mobility, which occurs after the bugs have had their blood meals. This was quite evident among all the species except T. infestans which thus showed no tedency for displacement from this environment. Domiciliarity was also evident among P. megistus and, to a lower degree, among T. brasiliensis, T. pseudomaculata and T. sordida. However, domiciliarity was not characteristics of R. nasutus. Information on geographical distribution confirms the autochthonous quality of T. brasiliensis, T. pseudomaculata and R. nasutus populations in the "caatinga". The same autochthonous feature was evident in the P. megistus with relation to the Atlantic and inclusion forest environments. Nevertheless, it seems that this last triatominae bug becomes invasive in the "caatinga"; moreover similar patterns were evident for T. infestans and T. sordida in all the Northeast region studied. Results permit the conclusion that, in the regional epidemiological transmission of South American trypanosomiasis, P. megistus play an important role, followed, in this particular aspect, by T

  11. Wing geometry of Triatoma sordida (Hemiptera: Reduviidae) populations from Brazil.

    Science.gov (United States)

    Vendrami, Daniel Pagotto; Obara, Marcos Takashi; Gurgel-Gonçalves, Rodrigo; Ceretti-Junior, Walter; Marrelli, Mauro Toledo

    2017-04-01

    Triatoma sordida has a widespread distribution in Argentina, Bolivia, Brazil, Paraguay, and Uruguay and is frequently found in peridomestic environments. We investigated size and shape variability of T. sordida wings across Brazil. Field-collected adults from twelve populations were studied. For each individual female, seven landmarks on the right wing were digitalized. Shape variables derived from Procrustes superimposition were used in Principal Component Analysis (PCA). Wing size and shape variations among populations was explored by means of ANOVA. Wing centroid size was significantly different among T. sordida populations; specimens from Bahia (East) were larger than those of Mato Grosso do Sul (West). PCA based on wing shape variables showed low wing shape variability. These results reinforce previous data showing low genetic variability among T. sordida populations from Brazil. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Distributional patterns of the American Peiratinae (Heteroptera: Reduviidae)

    NARCIS (Netherlands)

    Morrone, J.J.; Coscarón, del C M.

    1996-01-01

    Based on distributional data of 40 species of Peiratinae, historical relationships of five Amazonian areas (Paranaense, Atlantic, Pacific, Amazonian, and Cerrado) and two Chacoan areas (Chaco and Caatinga), were investigated through a parsimony analysis of endemicity (PAE). The resulting area

  13. Espermiogênese como ferramenta citotaxonômica para diferenciar Triatoma guazu e T. williami, espécies vetoras da doença de Chagas

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    Yago Visinho Reis

    2015-10-01

    Full Text Available Os triatomíneos pertencem à ordem Hemiptera, subordem Heteroptera, família Reduviidae e subfamília Triatominae. Todas as 148 espécies são hematófagas estritas e potenciais vetoras do protozoário Trypanosoma cruzi, agente etiológico da doença de Chagas. Algumas espécies são extremamente semelhantes do ponto de vista morfológico, o que pode dificultar o trabalho dos programas de controle de vetores. Triatoma guazu e T. williami são consideradas como espécies irmãs e não podem ser diferenciadas por diferentes abordagens, como análises morfométricas, isoenzimáticas e cromossômicas. Assim, o presente trabalho analisou as células haplóides durante a espermiogênese, com o objetivo de auxiliar na diferenciação desses vetores. A análise das espermátides de T. guazu e T. williami permitiu diferenciá-los, pois T. williami apresentou apenas um filamento heteropicnótico nas espermátides iniciais que foi parcialmente mantido durante o alongamento celular e T. guazu apresentou dois filamentos heteropicnóticos periféricos que se uniram durante o alongamento celular, dando origem a uma espermátide alongada totalmente heteropicnótica. Assim, ressaltando a importância dessa ferramenta na diferenciação de espécies relacionadas. No entanto, sugerimos que cruzamentos híbridos experimentais devem ser realizados entre esses triatomíneos, com o intuito de confirmar o status específico desses insetos vetores da doença de Chagas.Palavras-chave: Citogenética. Espermátides. Triatominae. Subcomplexo Matogrossensis. ABSTRACT Triatomines belong to the Hemiptera order, Heteroptera suborder, Reduviidae family and Triatominae subfamily. All the 148 species are haematophagous strict and potential vectors of the protozoan Trypanosoma cruzi, etiologic agent of Chagas disease. Some species are very similar from a point of view morphological, what can difficult the work of vector control programs. Triatoma guazu and T. williami are

  14. Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

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    Sebastian Pita

    2013-05-01

    Full Text Available In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae. The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome or both sex chromosomes (X and Y chromosomes. This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

  15. Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

    Science.gov (United States)

    Pita, Sebastián; Panzera, Francisco; Ferrandis, Inés; Galvão, Cleber; Gómez-Palacio, Andrés; Panzera, Yanina

    2013-01-01

    In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae). The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome) or both sex chromosomes (X and Y chromosomes). This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes) and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences. PMID:23778665

  16. The impact of climate change on the geographical distribution of two vectors of Chagas disease: implications for the force of infection

    Science.gov (United States)

    Medone, Paula; Ceccarelli, Soledad; Parham, Paul E.; Figuera, Andreína; Rabinovich, Jorge E.

    2015-01-01

    Chagas disease, caused by the parasite Trypanosoma cruzi, is the most important vector-borne disease in Latin America. The vectors are insects belonging to the Triatominae (Hemiptera, Reduviidae), and are widely distributed in the Americas. Here, we assess the implications of climatic projections for 2050 on the geographical footprint of two of the main Chagas disease vectors: Rhodnius prolixus (tropical species) and Triatoma infestans (temperate species). We estimated the epidemiological implications of current to future transitions in the climatic niche in terms of changes in the force of infection (FOI) on the rural population of two countries: Venezuela (tropical) and Argentina (temperate). The climatic projections for 2050 showed heterogeneous impact on the climatic niches of both vector species, with a decreasing trend of suitability of areas that are currently at high-to-moderate transmission risk. Consequently, climatic projections affected differently the FOI for Chagas disease in Venezuela and Argentina. Despite the heterogeneous results, our main conclusions point out a decreasing trend in the number of new cases of Tr. cruzi human infections per year between current and future conditions using a climatic niche approach. PMID:25688019

  17. Behavioural responses to human skin extracts and antennal phenotypes of sylvatic first filial generation and long rearing laboratory colony Rhodnius prolixus

    Directory of Open Access Journals (Sweden)

    Mario Iván Ortiz

    2011-06-01

    Full Text Available Chagas disease is a major public health issue and is mainly spread by Triatominae insects (Hemiptera: Reduviidae. Rhodnius prolixus is the main vector species in Northern South America. Host-seeking behaviour in R. prolixus is mediated by different compounds that are produced by and emanate from the host or microbiota on the host's skin. We tested the behavioural responses of sylvatic first filial generation (F1 and colony insects to extracts of human skin with a dual choice olfactometer. In addition, we compared the antennal phenotypes in both populations. No statistical differences were found between the two populations at the behavioural level. Both showed a preference for face and feet extracts and this effect was abolished for face extracts after treatment with an antibacterial gel. The observation of the antennal phenotype showed that there were differences between both groups in the total length, total surface area and number and density of bristles. However, the number and density of chemoreceptive sensilla (basiconic and thin and thick-walled trichoids and the total density of sensilla did not show statistically significant differences. These results demonstrate that colony insects, which have only been fed with living hens for the last 30 years, are attracted by human skin extracts in a similar way as F1 sylvatic insects.

  18. Description of the diploid chromosome set of Triatoma pintodiasi (Hemiptera, Triatominae).

    Science.gov (United States)

    Alevi, K C C; Moreira, F F F; Jurberg, J; Azeredo-Oliveira, M T V

    2016-04-25

    Triatoma pintodiasi has been described and recently grouped in the Rubrovaria subcomplex. T. pintodiasi was initially compared to T. carcavalloi by staining and subsequently identified as T. circummaculata. However, after thorough examination, it was observed to be a cryptic species of T. circummaculata, and was described based on morphological features, morphometric data, and biochemical patterns of hemolymph. Thus, this paper aims to describe the karyotype of, and spermatogenesis in, T. pintodiasi, in order to elucidate the reproductive biology and taxonomy of the species. Sex chromosomes of T. pintodiasi formed a heteropyknotic chromocenter, and compaction of chromatin was observed during prophase. However, in contrast to observations in T. carcavalloi and T. circummaculata, in T. pintodiasi it was observed individualization of the sex chromosomes. The diploid chromosome set of the species 2n = 22 (20A + XY) is described through analysis of metaphases I and II. Initial cytogenetic characteristics of T. pintodiasi are described and the observed differences in the chromocenter are suggested as a possible cytotaxonomic tool. To gain a better understanding of the specific status of this cryptic species, however, we emphasize the need for further cytogenetic, molecular, biological, and biogeographical analysis, in addition to experimental hybrid crosses with other species of the Rubrovaria subcomplex.

  19. Spermatogenesis and nucleolar behavior in Triatoma vandae and Triatoma williami (Hemiptera, Triatominae).

    Science.gov (United States)

    Pereira, N P; Alevi, K C C; Mendonça, P P; Azeredo-Oliveira, M T V

    2015-10-09

    This study describes spermatogenesis in Triatoma vandae and the nucleolar behavior of T. vandae and Triatoma williami, with a cytotaxonomic focus. Analysis of mitotic and meiotic metaphases of T.vandae confirms the species karyotype. T. vandae presents some characteristics during meiosis that differentiate it from T. williami, including the presence of a chromocenter with two sex chromosomes individualized during early prophase, and the presence of a bi- or tripartite corpuscle inpolyploid nuclei. It was possible to observe the compaction of chromatin during prophase resulting in holocentric chromosomes. During metaphase,the autosomes presented a ring shape and the sex chromosomes were in the center of the ring. These chromosomes were separated in anaphase. Although it is common, we did not observe the phenomenon of late migration of the sex chromosomes. By means of silver ion impregnation it was possible to describe nucleologenesis in T. vandae and T. williami. In both species we observed persistence of the nucleolar material duringmeiosis. In addition to the cells in meiotic division, we also observed the presence of polyploid nuclei in the seminiferous tubule walls that nourish the cells during cell division. The nucleolar markings reflect their capacity for synthetic activity. T. vandae and T. williami presented only one nucleolar corpuscle, which reflects low synthetic activity. This study confirms the karyotype of T. vandae, describes characteristics that differentiate T. vandae and T. williami during meiosis, and describes the phenomenon of nucleolar persistence in both species.

  20. The ecotopes and evolution of triatomine bugs (triatominae and their associated trypanosomes

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    Gaunt Michael

    2000-01-01

    Full Text Available Triatomine bug species such as Microtriatoma trinidadensis, Eratyrus mucronatus, Belminus herreri, Panstrongylus lignarius, and Triatoma tibiamaculata are exquisitely adapted to specialist niches. This suggests a long evolutionary history, as well as the recent dramatic spread a few eclectic, domiciliated triatomine species. Virtually all species of the genus Rhodnius are primarily associated with palms. The genus Panstrongylus is predominantly associated with burrows and tree cavities and the genus Triatoma with terrestrial rocky habitats or rodent burrows. Two major sub-divisions have been defined within the species Trypanosoma cruzi, as T. cruzi 1 (Z1 and T. cruzi 2 (Z2. The affinities of a third group (Z3 are uncertain. Host and habitat associations lead us to propose that T. cruzi 1 (Z1 has evolved in an arboreal, palm tree habitat with the triatomine tribe Rhodniini, in association with the opossum Didelphis. Similarly we propose that T. cruzi (Z2 and Z3 evolved in a terrestrial habitat in burrows and in rocky locations with the triatomine tribe Triatomini, in association with edentates, and/or possibly ground dwelling marsupials. Both sub-divisions of T. cruzi may have been contemporary in South America up to 65 million years ago. Alternatively, T. cruzi 2 (Z2 may have evolved more recently from T. cruzi 1 (Z1 by host transfers into rodents, edentates, and primates. We have constructed a molecular phylogeny of haematophagous vectors, including triatomine bugs, which suggests that faecal transmission of trypanosomes may be the ancestral route. A molecular clock phylogeny suggests that Rhodnius and Triatoma diverged before the arrival, about 40 million years ago, of bats and rodents into South America.

  1. Alkaline phosphatase activity in salivary gland cells of Rhodnius neglectus and R. prolixus (Hemiptera, Triatominae).

    Science.gov (United States)

    Lima-Oliveira, A P M; Alevi, K C C; Anhê, A C B; Azeredo-Oliveira, M T V

    2016-07-29

    Alkaline phosphatase activity was detected in salivary gland cells of the Rhodnius neglectus Lent, 1954, and R. prolixus Stal, 1859, vectors of Trypanosoma cruzi Chagas, 1909 (etiological agent of Chagas disease) and T. rangeli Tejera, 1920 (pathogenic to insect). The Gomori technique was used to demonstrate alkaline phosphatase activity. Alkaline phosphatase activity was observed throughout the entire gland, with an increased activity in the posterior region of the principal gland. In particular, phosphatase activity was found in the nucleolar corpuscles, suggesting a relationship with the rRNA transcription and ribosomal biogenesis. Alkaline phosphatase was also detected in the nuclear membrane and nuclear matrix, suggesting an association with the nucleo-cytoplasmic transport of ribonucleoproteins and the mechanisms of cell cycle and DNA replication, respectively. This study highlights the importance of alkaline phosphatase in the salivary gland of R. prolixus and R. neglectus and emphasizes its importance in secretory activity. Secretory activity is directly involved in hematophagy and, consequently, in development during metamorphosis. The observed presence of alkaline phosphatase suggests its involvement in the production of saliva allowing feeding of these insects that are important vectors of Chagas disease.

  2. Ecology of Triatoma rubrovaria (Hemiptera, Triatominae in wild and peridomestic environments of Uruguay

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    Roberto Salvatella

    1995-06-01

    Full Text Available This paper describes population structure, spatial distribution and habitat selection of wild and peridomestic populations of Triatoma rubrovaria (Blanchard, 1843. Field studies were carried out at Las Piedras and La Bolsa in the Northern Department of Artigas, Uruguay. A semicircular sampling area, divided in seven or eight triangular sectors was sequentially examined from October 1990 to November 1991. At Las Piedras (typical wild habitat 1063 T. rubrovaria bugs were collected from 84 of the rocky outcroops ("pedregales". Abundance varied by season peaking in October-November (spring. Throughout the year, most of the population was made up of third, fourth and fifth instar nymphs; adults were found from October to March. In the peridomestic environment of La Bolsa, however T. rubrovaria was less common and showed a more irregular instar distribution. Colonized ecotopes, were those close to houses. In both sites T. rubrovaria was mainly associated with the geckonid Homonota uruguayensis and the cockroach Blaptica dubia.

  3. Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae with Mycobacterium leprae Indicates Potential for Leprosy Transmission.

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    Arthur da Silva Neumann

    Full Text Available Leprosy is a chronic dermato-neurological disease caused by infection with Mycobacterium leprae. In 2013 almost 200,000 new cases of leprosy were detected around the world. Since the first symptoms take from years to decades to appear, the total number of asymptomatic patients is impossible to predict. Although leprosy is one of the oldest records of human disease, the mechanisms involved with its transmission and epidemiology are still not completely understood. In the present work, we experimentally investigated the hypothesis that the mosquitoes Aedes aegypti and Culex quinquefasciatus and the hemiptera Rhodnius prolixus act as leprosy vectors. By means of real-time PCR quantification of M. leprae 16SrRNA, we found that M. leprae remained viable inside the digestive tract of Rhodnius prolixus for 20 days after oral infection. In contrast, in the gut of both mosquito species tested, we were not able to detect M. leprae RNA after a similar period of time. Inside the kissing bug Rhodnius prolixus digestive tract, M. leprae was initially restricted to the anterior midgut, but gradually moved towards the hindgut, in a time course reminiscent of the life cycle of Trypanosoma cruzi, a well-known pathogen transmitted by this insect. The maintenance of M. leprae infectivity inside the digestive tract of this kissing bug is further supported by successful mice footpad inoculation with feces collected 20 days after infection. We conclude that Rhodnius prolixus defecate infective M. leprae, justifying the evaluation of the presence of M. leprae among sylvatic and domestic kissing bugs in countries endemic for leprosy.

  4. Ultrastructural analysis of the nucleolar aspects at spermiogenesis in triatomines (Heteroptera, Triatominae).

    Science.gov (United States)

    Morielle-Souza, Alessandra; Taboga, Sebastião Roberto; de Azeredo-Oliveira, Maria Tercília Vilela

    2010-10-01

    In this study the ultrastructural technique was used to analyze seminiferous tubule cells of the triatomine species Panstrongylus megistus, Rhodnius pallescens and Triatoma infestans. The data obtained provided evidence of the phenomenon known as persistence of the nucleolar material in initial spermatids at early differentiation. Our results confirmed the presence of the nucleolus and its products during spermiogenesis up to the formation of the axoneme and during spermatid elongation in all three species studied, similar to the process that takes place during cell division. In early spermatids, the nucleoli had a reticulate appearance and a well defined nucleolonema in P. megistus; showed a clear distinction between the fibrillar and the granular component in T. infestans; and had a compact aspect in R. pallescens. In this study, ultrastructural analyses at spermiogenesis indicated that these nucleolar products may represent RNP complexes that will probably be needed at early spermiogenesis when important changes such as chromatin condensation and acrosome and flagellum formation take place. Therefore, it was concluded from the ultrastructural analysis that the triatomine nucleolus does not totally disappear but remains as corpuscles that gather to form the next nucleolar cycle that in the case of meiosis, will be completed if fertilization occurs and a zygote is formed.

  5. Morphology and morphometry of the scutellum of six species in the genus Meccus (Hemiptera: Triatominae).

    Science.gov (United States)

    Rivas, Nancy; Sánchez Espíndola, Ma Esther; Camacho, Alejandro D; Ramírez Moreno, Ernesto; Rocha-Gómez, Ma Alejandra; Alejandre Aguilar, Ricardo

    2014-06-01

    We studied the morphology and morphometry of scutella from six species of the hemipteran genus Meccus to identify new tools to help solve taxonomic problems in closely related insect species of epidemiological relevance. Scutellum samples were observed by scanning electron microscopy and were subjected to morphometric analysis. The results mainly show differences in central depression shape, posterior process, and vestiture. We found significant dimensional differences in scutellum morphometry and a clear sexual dimorphism among species. A combination of morphology and morphometry can be used to differentiate among species of the genus Meccus. © 2014 The Society for Vector Ecology.

  6. Study of the nucleolar cycle and ribosomal RNA distribution during meiosis in triatomines (Triatominae, Heteroptera).

    Science.gov (United States)

    Morielle-Souza, Alessandra; de Azeredo-Oliveira, Maria Tercília Vilela

    2008-10-01

    Aspects of nucleolar activity during spermatogenesis were assessed in three triatomine species (Panstrongylus megistus, Rhodnius pallescens and Triatoma infestans) using cytochemical and fluorescent staining techniques. Toluidine blue and a variant of critical electrolytic concentration (CEC) allowed the discrimination of rRNA providing structural details of the nucleolus and RNA distribution during meiotic cell division. Acridine orange fluorochrome staining permitted the differentiation of nucleic acids, and silver-ion impregnation made possible the observation of pre-nucleolar bodies (PNBs). Our results support the phenomenon known as "persistence of the nucleolar material", and the hypothesis of post-meiotic reactivation of rRNA genes. Nucleolar organizer regions (NORs) were observed in some metaphasic spermatogonial chromosomes in P. megistus and T. infestans. In P. megistus at diplotene-diakinesis, NORs were also detected in one of the sex chromosomes and in an autosome. Therefore, it may be inferred that, in triatomines, the nucleolus does not completely disappear, but persists in the form of small bodies that get together to form the next nucleolar cycle which, in the case of meiosis, will be completed if fertilization occurs and a new zygote is formed.

  7. Validation of a less invasive blood sampling technique in rabies serology using reduviid bugs (Triatominae, Hemiptera).

    Science.gov (United States)

    Vos, Ad C; Müller, Thomas; Neubert, Larissa; Voigt, Christian C

    2010-03-01

    During serologic rabies surveys, bleeding is often difficult or almost impossible in small or endangered mammals such as bats. Therefore, the usefulness of an alternative, less invasive technique--that is, the use of blood-sucking reduviid bugs (Dipetalogaster maximus and Rhodnius prolixus)--was investigated. Bugs were used in combination with a conventional method (retro-orbitale bleeding) to obtain blood samples from the same individual NMRI-mice (Mus musculus) vaccinated against rabies. Rabies virus-neutralizing antibody (VNA) titers between paired blood samples obtained from the same mice were compared. The accuracy (between-method comparison), precision (repeatability of results), and robustness (influence of digestion on blood parameter) of the bug method was evaluated. VNA titers in the blood sample obtained from the bugs' crops were equivalent to those from samples collected directly from the mice. No differences between samples taken from different bugs that had fed on the same mouse were noted. In addition, there were no changes in VNA titers in blood samples collected from the triatomine bugs for up to 4 hr after completion of the blood meal. This study demonstrates that the application of blood-sucking bugs offers a validated alternative for obtaining blood samples to determine rabies virus-neutralizing antibody titers and is highly suitable for animals with limited or no accessibility of veins by conventional sampling techniques.

  8. Invasion of rural houses by wild Triatominae in the arid Chaco.

    Science.gov (United States)

    Cavallo, María J; Amelotti, Ivana; Gorla, David E

    2016-06-01

    Triatomines are the vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease, the main endemic disease affecting five to seven million people in Latin America. Besides Triatoma infestans, the most important T. cruzi vector in the Gran Chaco region, other triatomine species associated with sylvatic birds and mammals are responsible for the maintenance of the wild cycle of T. cruzi. The present study aimed at evaluating the house invasion by sylvatic triatomine species in rural communities of the Los Llanos region (La Rioja, Argentina) and its association with environmental variables. House invasion by flying adult triatomines was recorded by trained collectors that surveyed over 377 houses distributed over 73 localities in a 56,600 km(2) study region, between October, 2014 and February, 2015. The result of the study showed the frequent house invasion by adult triatomines: 26.3% houses were infested in 53% of the localities. Seven sylvatic triatomine species were collected, with T. guasayana and T. garciabesi among the most abundant. House invasion by triatomine species showed no spatial aggregation and was not associated with temperature, precipitation, or vegetation cover at the spatial scale considered in the present study. House invasion by the epidemiologically important T. infestans is a concern of rural communities. Besides constituting a latent, although low, risk, the presence of these species negatively interferes with the vigilance activities of the provincial Chagas disease program. © 2016 The Society for Vector Ecology.

  9. Spontaneous morphogenetic juvenilization observed in laboratory populations of vector species of Chagas disease (Triatominae

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    Alina Perlowagora-Szumlewicz

    1973-08-01

    Full Text Available Reported are observations on spontaneous occurring morphogenetic juvenilization in laboratory populations of vector species of Chagas disease. Two general effects have been observed: arrested development and uncoordinated development. These are manifested by supernumerary nymphs (6th stage, intermediate nymphal-adult stages, badly deformed adults developed from 5th instar nymphs, uncoordinated development manifested by grotesque forms of adults, supernumerary adults unable to complete metamorphosis and complete supernumerary adults produced by 6th stage nymphs. The reoccurrence of insects with identical grades of juvenilization in the population is an indication that this is a genetic trait that might be inherited. The factors responsible for morphogenetic juvenilization cannot be transmitted through the juvenilized insects because they are sterile, than they were transmitted through normal insects probably as a recessive or a group recessive factors. The spontaneous morphogenetic juvenilization observed in laboratory populations has a striking similarity to juvenilizing effects induced by application of juvenile hormone analogues, described in the literature and also obtained in our laboratory in a study to be published. Thus it is suggested that both; the altered phenotypes occurring in wild populations and their "phenocopies" induced by the application of juvenile hormone analogues are products of gene controlled identical reactions.

  10. Spontaneous morphogenetic juvenilization observed in laboratory populations of vector species of Chagas disease (Triatominae

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    Alina Perlowagora-Szumlewicz

    1973-08-01

    Full Text Available Reported are observations on spontaneous occurring morphogenetic juvenilization in laboratory populations of vector species of Chagas disease. Two general effects have been observed: arrested development and uncoordinated development. These are manifested by supernumerary nymphs (6th stage, intermediate nymphal-adult stages, badly deformed adults developed from 5th instar nymphs, uncoordinated development manifested by grotesque forms of adults, supernumerary adults unable to complete metamorphosis and complete supernumerary adults produced by 6th stage nymphs. The reoccurrence of insects with identical grades of juvenilization in the population is an indication that this is a genetic trait that might be inherited. The factors responsible for morphogenetic juvenilization cannot be transmitted through the juvenilized insects because they are sterile, than they were transmitted through normal insects probably as a recessive or a group recessive factors. The spontaneous morphogenetic juvenilization observed in laboratory populations has a striking similarity to juvenilizing effects induced by application of juvenile hormone analogues, described in the literature and also obtained in our laboratory in a study to be published. Thus it is suggested that both; the altered phenotypes occurring in wild populations and their "phenocopies" induced by the application of juvenile hormone analogues are products of gene controlled identical reactions.São relatadas observações sobre a ocorrência espontâea de juvenilização morfogenética em populações de espécies transmissoras da doença de Chagas, mantidas no laboratório. Dois efeitos gerais foram observados: a interrupção e a descoordenação do desenvolvimento. Tais efeitos são manifestados: 1 por ninfas supernumerárias (6º estádio, 2 por estágios intermediários (ninfa-adulto, 3 por adultos sensivelmente deformados, provenientes de ninfas do 5º estágio, 4 pelo desenvolvimento dèscoordenado manifestado por formas adultas grotescas, 5 por adultos supernumerários incapazes de completar sua metamorfose e 6 por adultos supernumerários completos, produzidos por ninfas de 6º estágio. A remetida ocorrência de insetos com idênticos graus de juvenilização, dentro de uma população, é uma indicação de que existe nestes casos, uma aberração hereditária. Os fatores responsáveis pela juvenilização morfogenética não podem ser transmitidos através de insetos juvenilizados, porque esses são estéreis, consequentemente foram transmitidos através de insetos normais, provavelmente como um recessivo ou um grupo de fatores recessivos. A juvenilização morfogenética espontânea, observada em populações de laboratório, tem notável similaridade com os efeitos juvenilizantes induzidos pela aplicação de hormônios juvenis análogos, descritos na literatura e também obtidos no nosso laboratório num estudo em vias de publicação. Desse modo, admite-se que, não só as alterações fenotipicas que ocorrem nas populações naturais, mas também as suas "fenocópias" induzidas pela aplicação de hormônios juvenis, sejam fenômenos produzidos por reações idênticas, geneticamente controladas.

  11. Triatoma melanosoma, novo status para Triatoma infestans melanosoma Martinez, Olmedo & Carcavallo, 1987 (Hemiptera: Reduviidae Triatoma melanosoma, new status for Triatoma infestans melanosoma Martinez, Olmedo & Carcavallo, 1987 (Hemiptera: Reduviidae

    Directory of Open Access Journals (Sweden)

    Herman Lent

    1994-09-01

    Full Text Available Triatoma infestans melanosoma was described in 1987 by Martinez, Olmedo & Carcavallo. In the present work the authors make a redescription, adding new characters, and based on biological and morphological aspects raise up to the level of species and being identified as Triatoma melanosoma. A detailed morphological study of the external male genitalia was made.

  12. Insecticidal action of synthetic girgensohnine analogues and essential oils on Rhodnius prolixus (Hemiptera: Reduviidae

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    Juliana Cuadros

    2017-03-01

    Conclusion: Synthetic girgensohnine analogues, and C. flexuosus and C. sinensis essential oils showed insecticidal activity in R. prolixus. Analogue 3 showed the greatest insecticidal activity among all molecules and oils evaluated under our laboratory conditions.

  13. Biology of Triatoma sherlocki (Hemiptera: Reduviidae) Under Laboratory Conditions: Biological Cycle and Resistance to Starvation.

    Science.gov (United States)

    Lima-Neiva, Vanessa; Gonçalves, Teresa C M; Bastos, Leonardo S; Gumiel, Marcia; Correia, Nathália C; Silva, Catia C; Almeida, Carlos E; Costa, Jane

    2017-07-01

    Triatoma sherlocki Papa, Jurberg, Carcavallo, Cerqueira & Barata was described in 2002, based on specimens caught in the wild in the municipality of Gentio do Ouro, Bahia, Brazil. In 2009, nymphs and adults were detected inside homes and sylvatic specimens were positive for Trypanosoma cruzi (Chagas). No information on the bionomics of T. sherlocki exists, although such data are considered essential to estimate its vector and colonization potential in domestic environments. Herein, the biological cycle of T. sherlocki was studied based on 123 eggs, with nymphs and adults fed on Mus musculus (Linnaeus). Nymphal development time phases, number of meals consumed, and stage-specific mortality rates were analyzed. Survival time under starvation conditions was measured between ecdysis and death among 50 nymphs (first to fifth instar) and 50 male and female adults. The median development time from egg to adult was 621.0 (CI: 489-656) d. The number of meals consumed ranged from 1 to 20 for nymphs of the first to fifth instar. The fifth instar showed the greatest resistance to starvation, with a mean of 156.5 d. The high number of meals consumed by T. sherlocki favored infection with and transmission of T. cruzi. The full development of this species under laboratory conditions with a low mortality rate indicates that this vector presents biological characteristics that may contribute to its adaptation to artificial human ecotopes. Its high resistance to starvation emphasizes the importance of entomological surveillance for this species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Morphological and Genetic Differentiation within the Southernmost Vector of Chagas Disease: Triatoma patagonica (Hemiptera - Reduviidae).

    Science.gov (United States)

    Nattero, Julieta; Pita, Sebastián; Calleros, Lucía; Crocco, Liliana; Panzera, Yanina; Rodríguez, Claudia S; Panzera, Francisco

    2016-01-01

    The epidemiological importance of Chagas disease vectors largely depends on their spreading ability and adaptation to domestic habitats. Triatoma patagonica is a secondary vector of Chagas disease endemic of Argentina, and it has been found colonizing domiciles and most commonly peridomiciliary structures in several Argentine provinces and morphological variation along its distribution range have been described. To asses if population differentiation represents geographic variants or true biological species, multiple genetic and phenotypic approaches and laboratory cross-breeding were performed in T. patagonica peridomestic populations. Analyses of chromatic variation of forewings, their size and the content of C-heterochromatin on chromosomes revealed that populations are structured following a North-South latitudinal variation. Cytochrome c oxidase I mitochondrial gene (COI) nucleotide analysis showed a mean genetic distance of 5.2% between the most distant populations. The cross-breeding experiments suggest a partial reproductive isolation between some populations with 40% of couples not laying eggs and low hatching efficiency. Our findings reveal phenotypic and genetic variations that suggest an incipient differentiation processes among T. patagonica populations with a pronounced phenotypic and genetic divergence between the most distant populations. The population differentiation here reported is probably related to differential environmental conditions and it could reflect the occurrence of an incipient speciation process in T. patagonica.

  15. Triatoma costalimai (Hemiptera: Reduviidae) in and Around Houses of Tocantins State, Brazil, 2005-2014.

    Science.gov (United States)

    Nogueira Brito, Raíssa; Diotaiuti, Liléia; Celencina Fagundes Gomes, Anália; de Cássia Moreira de Souza, Rita; Abad-Franch, Fernando

    2017-11-07

    Triatoma costalimai Verano & Galvão, a little-known vector of Trypanosoma cruzi Chagas, occupies rocky environments in the Brazilian Cerrado and occasionally infests man-made habitats. Entomological surveillance records show that T. costalimai occurs fairly often inside and around houses in south-eastern Tocantins, Brazil, with 859 specimens reported in 2005-2014. Most adults were caught indoors, and breeding colonies were found inside and around houses. Trypanosoma cruzi was detected in 13.7% of 839 bugs. These data suggest that T. costalimai can contribute to T. cruzi transmission in human environments, underscoring the need for long-term entomological-epidemiological surveillance wherever native Chagas disease vectors occur. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Serine carboxypeptidases of Triatoma brasiliensis (Hemiptera, Reduviidae): Sequence characterization, expression pattern and activity localization.

    Science.gov (United States)

    Waniek, Peter J; Araújo, Catarina A C; Momoli, Marisa M; Azambuja, Patricia; Jansen, Ana M; Genta, Fernando A

    2014-04-01

    Using specific oligonucleotides, 5'- and 3'-RACE and sequencing, two cDNAs encoding serine carboxypeptidases (tbscp-1 and tbscp-2) from the midgut of the blood sucking heteropteran Triatoma brasiliensis were identified. Both cDNAs with an open reading frame of 1389bp, encode serine carboxypeptidase precursors of 463 amino acid residues, which possess a signal peptide cleavage site after Ala19. Analysis of tbscp-1 and tbscp-2 genomic DNA showed an absence of introns in both sequences and the presence of a further intron-free SCP encoding gene (tbscp-2b). By reverse transcription polymerase chain reaction (RT-PCR), tbscp-1 and tbscp-2 transcript abundance was found similarly in fifth instar nymphs at different days after feeding (daf), high in the posterior midgut (small intestine), lower in the anterior midgut (stomach) and fat body and almost undetectable in the salivary glands. In the anterior, middle and posterior regions of the small intestine at 5daf the transcript abundance of both genes was almost identical. Also in adult female and male insects at 5daf both genes showed the strongest signal in the posterior midgut. Molecular modeling suggested that TBSCP-1 has carboxypeptidase D activity; activities against Hippuryl-Phenylalanine and Hippuryl-Arginine were also located at the posterior midgut, both were induced after blood feeding. Treatment of the posterior midgut extracts with the serine protease inhibitor PMSF strongly reduced carboxypeptidase activity. These findings suggest that triatomines might use serine carboxypeptidases, which are usually found in lysosomes, as digestive enzymes in the posterior midgut lumen, from which TBSCP-1 and TBSCP-2 are possible candidates to fulfill this function. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Morfologia de ovos de Triatoma circummaculata e Triatoma rubrovaria (Hemiptera, Reduviidae

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    João A da Rosa

    2000-10-01

    Full Text Available OBJETIVO: Estudar morfologicamente ovos de T. circummaculata e T. rubrovaria. MÉTODOS: Quarenta ovos das duas espécies foram mensurados por meio de projetor de perfil Nikon modelo 6C, e utilizado o teste Student, para execução da análise estatística. As observações morfológicas foram feitas em microscópio eletrônico de varredura JEOL, modelo JSM-T330A. RESULTADOS/CONCLUSÕES: A análise estatística revelou que os ovos e as cascas de ovos de T. rubrovaria são significativamente maiores que os de T. circummaculata. Observações microscópicas mostraram que a borda corial, assim como a goteira espermática, são bem mais evidentes nos ovos de T. rubrovaria que nos de T. circummaculata. O exocório das duas espécies é formado por áreas poligonais, que são hexagonais em sua maioria. Foram observados também o momento da eclosão do embrião e os detalhes das exúvias embrionárias.

  18. First records of Triatoma rubrofasciata (De Geer, 1773) (Hemiptera, Reduviidae) in Foshan, Guangdong Province, Southern China.

    Science.gov (United States)

    Liu, Qin; Guo, Yun-Hai; Zhang, Yi; Zhou, Zheng-Bin; Zhang, Liang-Liang; Zhu, Dan; Zhou, Xiao-Nong

    2017-08-15

    Triatomines, also known as kissing bugs, which are found throughout the world and especially in Latin America, are well known natural vectors that transmit American trypanosomiasis, also called Chagas disease. In China, the presence of two species of Triatoma (Triatoma rubrofasciata and T. sinica) was recorded in the past. Due to the growing population and the increasing risk of the global spread of Chagas disease, triatomines became a potential public health nuisance, and in 2016, we started monitoring triatomine activities in southern China. Triatomine specimens were collected by the National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, and identified by their morphological characteristics under a dissecting microscope. In addition to morphological analysis, the genomic DNA of the specimens was extracted, and the mitochondrial 16S rRNA, the cytochrome b (CytB) gene and the nuclear ribosomal 28S rRNA gene were PCR-amplified to analyze and confirm the species genetically. One female adult insect and one male adult insect were collected in a dwelling in the rural area of Shunde County, Foshan City, Guangdong Province, China (22°42'44.63″N, 113°08'45.34″E). The results from the morphological and genetic analyses indicated that these triatomines were T. rubrofasciata. This is the first time that the occurrence of T. rubrofasciata has been confirmed in Foshan City, Guangdong Province in southern China. Further studies are needed to reach a clearer understanding of the ecology of this species of triatomine, since it has been found to be naturally infected by Trypanosoma cruzi and T. conorhini and there is evidence of its domiciliation capabilities.

  19. Eco-geographical differentiation among Colombian populations of the Chagas disease vector Triatoma dimidiata (Hemiptera: Reduviidae).

    Science.gov (United States)

    Gómez-Palacio, Andrés; Triana, Omar; Jaramillo-O, Nicolás; Dotson, Ellen M; Marcet, Paula L

    2013-12-01

    Triatoma dimidiata is currently the main vector of Chagas disease in Mexico, most Central American countries and several zones of Ecuador and Colombia. Although this species has been the subject of several recent phylogeographic studies, the relationship among different populations within the species remains unclear. To elucidate the population genetic structure of T. dimidiata in Colombia, we analyzed individuals from distinct geographical locations using the cytochrome c oxidase subunit 1 gene and 7 microsatellite loci. A clear genetic differentiation was observed among specimens from three Colombian eco-geographical regions: Inter Andean Valleys, Caribbean Plains and Sierra Nevada de Santa Marta mountain (SNSM). Additionally, evidence of genetic subdivision was found within the Caribbean Plains region as well as moderate gene flow between the populations from the Caribbean Plains and SNSM regions. The genetic differentiation found among Colombian populations correlates, albeit weakly, with an isolation-by-distance model (IBD). The genetic heterogeneity among Colombian populations correlates with the eco-epidemiological and morphological traits observed in this species across regions within the country. Such genetic and epidemiological diversity should be taken into consideration for the development of vector control strategies and entomological surveillance. Copyright © 2013. Published by Elsevier B.V.

  20. Scanning electron microscopy of the dorsal vessel of Panstrongylus megistus (Burmeister, 1835 (Hemiptera: Reduviidae

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    Nadir Francisca Sant'Anna Nogueira

    1991-03-01

    Full Text Available In this study we analyzed the microanatomy of the dorsal vessel of the triatomine Panstrongylus megistus. The organ is a tuble anatomically divided into an anterior aorta anad a posterior heart, connected to the body wall through 8 pairs of alary muscles. The heart is divided in 3 chambers by means of 2 pairs of cardiac valves. a pair of ostia can be observed in the lateral wall of each chamber. A bundle of nerve fibers was found outside the organ, running dorsally along its major axis. A group of longitudinal muscular fibers was found in the ventral portion of the vessel. The vessel was found to be lined both internally and externally by pericardial cells covered by a thin laminar membrane. Inseide the vessel the pericardial cells were disposed in layers and on the outside they formed clusters or rows.

  1. Mecanismo antidiurético en Rhodnius Prolixus (Stal, 1859 (Hemiptera, Reduviidae

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    Ivonne Gómez

    1986-12-01

    Full Text Available Se propone para R. prolixus un mecanismo antidiurético, cuya actividad se pone de manifiesto una vez transcurrido el periodo diurético y se mantiene hasta que el insecto es alimentado nuevamente. Presumiblemente este mecanismo actua a nivel del esfinter rectal proximal y es inhibido por la ingesta, distención mecanica del buche y desinhibición central por decapitación. Se sugiere que la actividad antidiurética es mantenida por vía nerviosa y se modifica cuando hay distensión del buche o canudo es interrumpida la senãl nerviosa por decapitación. Se pone de manifiesto que la excreción de orina en R. prolixus no es controlada exclusivamente por la hormona diurética, sino que factores no ligados a la hemolinfa mantienen en estado diurético y no diurético a los insectos.An antidiuretic mechanism is proposed for Rhodnius prolixus, whose activity is manifested when the diuretic phase has terminated and is maintained until the insect has fed again. Presumably this mechanism acts at the level of the proximal rectal sphincter and is inhibited by ingestion, mechanical distension of the gut and central desinhibition by decapitation. It is suggested that the antidiuretic activity is maintained by the nervous system and is modified when there is distention of the gut or when the nervous signal is interrupted by decapitacion. It is demonstrated that the excretion of urine in R. prolixus is not controlled exclusively by the diuretic hormone, but rather that factors not linked to the haemolvmph maintain the insects in a diuretic or nondiuretic state.

  2. Response of the reduviid bug, Rhynocoris marginatus (Heteroptera: Reduviidae) to six different species of cotton pests

    DEFF Research Database (Denmark)

    Sahayaraj, Kitherian; Muthu Kumar, Subramanian; Enkegaard, Annie

    2016-01-01

    In Indian agro-ecosystems Rhynocoris marginatus (F.) is one of the most abundant predatory arthropods and feeds on a wide range of insect pests. We investigated the responses of R. marginatus to six species of cotton pests: Spodoptera litura (F.), Sylepta derogata (F.), Pericallia ricini (F...... tended to be, for this predator, superior prey, with S. litura being especially beneficial and the prey species for which R. marginatus has the highest kairomonal preference. Moreover, we propose that R. marginatus may be useful as a biocontrol agent against lepidopteran cotton pests....

  3. Alberprosenia malheiroi Serra, Atzingen & Serra, 1987 (Hemiptera, Reduviidae): redescrição e bionomia

    OpenAIRE

    Carcavallo, Rodolfo U.; Barata, José M. S.; Costa, Antônio I. P. da; Serra, Oswaldo P.

    1995-01-01

    Sobre Alberprosenia malheiroi n. sp. deu-se a conhecer uma diagnose resumida em 1980, porém sem valor bibliográfico. Em 1987 publicou-se a mesma diagnose anexando uma foto e alguns comentários, porém sem realizar uma descrição formal. Descreve-se para esta espécie, os adultos, os estádios imaturos, determina-se a série sintípica e apresenta-se dados bionômicos e de criação em insetário. As diferenças mais evidentes com A. goyovargasi, a única espécie que se conhecia do gênero até então, são a...

  4. Biología del Predator Zelus Longipes Linneo (Hemiptero: Reduviidae en el Valle del Cauca

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    Unigarro P. Antonio

    1958-09-01

    Full Text Available Los insectos constituyen las plagas más dañinas para las cosechas, sea en el campo, en 'almacenamiento o en sus derivados. Afortunadamente, los insectos no son solamente dañinos; los hay también benéficos, toda vez que destruyen a los primeros. La utilización de los enemigos naturales de las plagas, para combatir éstas, constituye el control biológico. Los enemigos naturales de los insectos pueden ser de la mayor importancia y en no pocos casos han sido sorprendentes los resultados obtenidos al utilizar esta forma de control, en especial cuando estas prácticas han sido dirigidas por el hombre. No obstante, la utilidad del sistema es limitada, ya que su aplicación está estrictamente en manos de los entomólogos especializados en estas disciplinas, capacitados para la ejecución de estos trabajos. Hoy día los investigadores entomólogos estudian la importancia del control biológico tratando de utilizar los insectos benéficos contra los devastadores, aprovechándose de los medios que la misma Naturaleza les ha dado. Entre nosotros se ha prestado poca importancia a este aspecto de la entomología, y es precisamente lo que el autor del presente trabajo se propone demostrar con el estudio de la biología del Zelns Longipes Linneo, hemíptero, de amplia distribución en nuestro medio y cuya eficacia en la destrucción de varios insectos dañinos, es ya reconocida.

  5. Effects of juvenile hormone analogue on ecdysis prevention induced by precocene in Rhodnius prolixus (Hemiptera: Reduviidae

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    Patricia de Azambuja

    1984-12-01

    Full Text Available Precocene II, added to the meal of fourth-instar larvae of Rhodnius prolixus (25 mug/ml of blood, induced an in crease in the duration of the molting cycle. This effect was related to the decrease of both the nuclear area of the prothoracic gland cells and the mitotic activity in epidermal cellS. juvenile hormone analogue applied topically (60 mug/insect together with Precocene II treatment avoided atrophy of the prothoracic glands and induced a higher number of epidermal mitosis accelerating the time of subsequent ecdysis. A possible relationship between juvenile hormone and production of ecdysone is discussed.Adicionado ao sangue alimentar na dose de 25 mug/ml o precoceno II causou um aumento no período de intermuda em ninfas de 4o. estadio de Rhodnius prolixus. Este atraso da muda foi relacionado com a diminuição da área dos núcleos das celulas das glandulas protoracicas e com a queda da atividade mitotica das células da epiderme do inseto. Um análogo de hormônio juvenil aplicado topicamente (60 mug/inseto junto com o tratamento oral com precoceno II preveniu a atrofia das glândulas protorácicas e induziu um aumento no número de mitoses nas células da epiderme, diminuindo o período de intermuda nestes insetos.A possivel relação entre a ação do hormônio juvenil e a producao de ecdisona pelas glândulas protorácicas e discutida.

  6. Life cycle and reproductive patterns of Triatoma rubrofasciata (De Geer, 1773) (Hemiptera: Reduviidae), under laboratory conditions.

    Science.gov (United States)

    Braga, M V; Pinto, Z T; Lima, M M

    1998-01-01

    The life cycle and reproductive patterns of Triatoma rubrofasciata were studied along with laboratory conditions for the establishment of a prolific colony. The insects were divided into four groups: two of them were maintained at room temperature (20.5 degrees C to 33 degrees C and 85% +/- 5% of relative humidity), the other two in a climatic chamber (CC) (temperature: 29 degrees C, humidity: 80% +/- 5%). The groups were fed weekly or fortnightly on Swiss mice. The females from the group kept in the CC and fed weekly had longer life span, as well as a higher number of eggs, fertile eggs and hatchings; the group kept in the CC and fed fortnightly had a shorter life span for the 1st, 2nd and 3rd instars and a lower mortality rate for all instars. It was concluded that a constant high temperature (CC at 29 degrees C) is the most suitable condition for the maintenance of a colony of T. rubrofasciata regardless of the interval between repasts.

  7. The interaction between Poultry and Triatoma infestans Klug, 1834 (Hemiptera: Reduviidae in an experimental model

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    Nicolás J. Schweigmann

    1995-06-01

    Full Text Available This paper compares the predation pressure that ducks and chickens exert on triatomines. For the tests, these birds were placed in individual boxes together with a known number of Triatoma infestans and left to interact from 6 p.m. till the next morning, involving a long lasting period of complete darkness limited by two short-term periods of semi-darkness. There was a shelter which could prevent the bugs from being predated. The number of live and dead triatomines was recorded, considering missing bugs as predated by the birds. Ducks exhibited a greater predatory activity than chickens, that could be due to a long term active period at night while chickens sleep motionless from sunset to dawn. Surviving triatomines that had fed on chickens outnumbered those fed on ducks suggesting that these were less accessible to the triatomine biting. If ducks are better than chickens to detect and eat bugs and to interfere with their feeding in the field, an increase in duck number might help to diminish triatomine density. Further research is needed to determine the feasibility of application of these experimental results.

  8. Susceptibility characterization of residual Brazilian populations of Triatoma infestans Klug, 1834 (Hemiptera: Reduviidae to deltamethrin pyrethroid

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    Grasielle Caldas D`avila Pessoa

    2015-04-01

    Full Text Available INTRODUCTION: Despite years of efforts towards the elimination of Triatoma infestans in Brazil, residual foci still persist in some areas of the States of Bahia and Rio Grande do Sul. The persistence of these T. infestans populations in the country has two different origins of equal concern: operational failures or insecticide resistance. Thus, the objective of this study was to characterize the susceptibility profile of the residual Brazilian populations of T. infestans to deltamethrin. METHODS: The susceptibility reference lineage was derived from Cipein/Argentina. The populations studied were manually collected using a dislodging agent in peridomiciles in the States of Bahia (Novo Horizonte and of Rio Grande do Sul (Santa Rosa and Doutor Maurício Cardoso. Serial dilutions of deltamethrin were prepared and applied at the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed the mortality of a diagnostic dose of 1xLD99 (2.76ng a.i./nymph determined for the susceptibility reference lineage. RESULTS: The susceptibility profile characterization of the T. infestans populations revealed an RR50 ranging from 1.73 to 3.26. The mortality percentage in response to a diagnostic dose was 100%. The results obtained in the quantitative and qualitative assays corresponded for all populations. CONCLUSIONS: The results of this study indicate that the persistence of residual foci of T. infestans in Bahia and Rio Grande do Sul is not related to insecticide resistance but may be associated with operational failures. In Rio Grande do Sul, we must consider the possibility of continuous reinfestation by Argentinian individuals, which justifies active and efficient epidemiological surveillance.

  9. Occurrence of synanthropic triatomines (Hemiptera: Reduviidae in the Federal District of Brazil

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    Maicon Hitoshi Maeda

    2012-02-01

    Full Text Available INTRODUCTION: Entomological surveillance of Chagas disease in the Federal District of Brazil (DF, has recorded the following triatomine species: Panstrongylus megistus, P. geniculatus, P. diasi, Rhodnius neglectus, Triatoma pseudomaculata, and T. sordida. We aimed to analyze the spatial and temporal occurrence of triatomine species collected in DF, and their indices of natural infection with trypanosomes. METHODS: The Health State Secretariat of DF recorded triatomines between 2002 and 2010 in 20 administrative regions. This retrospective analysis considered the number of adults and nymphs of each species collected and infected in both intradomicile and peridomicile. RESULTS: A total of 754 triatomines were collected in 252 reported domiciles. Panstrongylus megistus was the most frequent species (65%, followed by T. pseudomaculata (14%. Of the 309 examined insects, only 3 (1% specimens of P. megistus were infected with flagellates morphologically similar to Trypanosoma cruzi. The spatial occurrence indicated a higher diversity of triatomines and frequency of T. sordida in rural areas. Moreover, there was a predominance of P. megistus in urban areas. The number of records of P. megistus in the rainy season was two times higher than that during the dry season. The largest number of triatomines was collected in November. CONCLUSIONS: The presence of P. megistus specimens infected with trypanosomes in domiciles, shows the potential risk of human infection in DF. Thus, it is essential to continue entomological surveillance, intensifying it in the rainy season and in regions of greater occurrence.

  10. Biocide activity of Annona coriacea seeds extract on Rhodnius neglectus (Hemiptera: Reduviidae

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    Ângela Pinheiro Carneiro

    2013-03-01

    Full Text Available The use of synthetic insecticides for insect control may lead to different kind of problems, such as vector resistance to insecticides. To avoid these problems, a new research area to study botanical products as possible disease vectors controls, has become a feasible alternative. The purpose of this research was to evaluate the biocide activity of the ethanol extract of seeds of Annona coriacea on Rhodnius neglectus (Chagas disease vector nymphs and adults. For this, different concentrations extracts were evaluated: 25, 50, 100 and 200mg/ mL, and water in DMSO (20% was used as control. The experimental design was completely randomized and we conducted the bioassay with nymphs and adults, with 10 nymphs and 10 adults (five males and five females per treatment. Extract action was evaluated in both bioassays, in order to identify possible effects of mortality and life cycle interruption of nymphs and adults during a 28-day-period. The results obtained showed that the extract of A. coriacea was able to disrupt the development of nymphs and adults of R. neglectus, with a mortality rate of more than 90%, 36% and 100%, at the highest concentrations, respectively. There was also molting inhibition in nymphs, lower reproductive capacity in females, feeding deterrence and morphological changes in nymphs and adults. We concluded that the extract of A. coriacea has insecticide action on nymphs and adults of R. neglectus.La enfermedad de Chagas se convirtió en un problema de salud debido a su importancia epidemiológica, es producida por el protista Trypanosoma cruzi, cuyos insectos vectores son del género Triatoma y Panstrongylus. El objetivo de este estudio fue evaluar la actividad biocida del extracto de Annona coriacea en las ninfas de Rhodnius neglectus y en sus adultos. Se evaluaron 14 concentraciones de 25, 50, 100 y 200mg/ml del extracto etanólico, así como el control, en este caso agua de DMSO (20%. Se utilizo un diseño completamente aleatorizado con tres repeticiones para el bioensayo con 10 ninfas y 10 adultos (cinco machos y cinco hembras para cada tratamiento. La acción del extracto se observo durante 28 días en ambos bioensayos. Los resultados obtenidos mostraron que el extracto de A. coriacea fue capaz de interrumpir el desarrollo de las ninfas y adultos de R. neglectus, con una mortalidad de más del 90%, 36% y 100%, correspondiendo a las concentraciones más altas. También hubo inhibición de la muda de las ninfas, una menor capacidad reproductiva de las hembras, disuasión alimentaria y cambios morfológicos en las ninfas y adultos. Se concluye que el extracto de A. coriacea presentó acción insecticida en ninfas y adultos de R. neglectus.

  11. Predicting the potential geographical distribution of Rhodnius neglectus (Hemiptera, Reduviidae) based on ecological niche modeling.

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    Gurgel-Goncalves, Rodrigo; Cuba, César Augusto Cuba

    2009-07-01

    Rhodnius neglectus is frequently found in palm trees and bird nests in sylvatic environments. However, adult specimens infected by Trypanosoma cruzi have been invading houses in central Brazil. Analyzing and predicting the geographical distribution of this species may improve vector surveillance strategies for Chagas disease. Ecological niche modeling using the genetic algorithm for rule-set production (GARP) was applied to predict the geographical distribution of R. neglectus from occurrence records and a set of 23 predictor variables (e.g., temperature, precipitation, altitude, and vegetation). Additionally, the geographical distribution of R. neglectus was compared with the geographical distribution of four species of palm trees and two species of birds from the study region. The models were able to predict, with high probability, the occurrence of R. neglectus as a regular (although nonendemic) species of the Cerrado biome in central Brazil. Caatinga, Amazonian savanna, Pantanal, and the Bolivian Chaco appear as areas with lower probabilities of potential occurrence for the species. A great overlap was observed between the distribution of R. neglectus, palm trees (Acrocomia aculeata and Syagrus oleracea), and birds (Phacellodomus ruber and Pseudoseisura cristata). By including new records for R. neglectus (from both sylvatic and domestic environments), our study showed a distribution increase toward the west and northeast areas of Brazil in the "diagonal of open/dry ecoregions of South America". These results should aid Chagas disease vector surveillance programs, given that household invasion by Rhodnius species maintains the risk of disease transmission and limits control strategies.

  12. [Distribution and characterization of different populations of Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae, Tritominae)].

    Science.gov (United States)

    Costa, J

    2000-01-01

    Triatoma brasiliensis Neiva, 1911 is now considered the most important Chagas disease vector in the semiarid zones of northeastern Brazil. Four distinct populations of T. brasiliensis have been identified by multidisciplinary studies: brasiliensis (Caicó, RN), melânica (Espinosa, MG), macromelasoma (Petrolina, PE), and juazeiro (Juazeiro, BA). By scanning electron microscopy of egg exochorion, each population displayed a distinct ornamentation pattern. The brasiliensis, macromelasoma, and juazeiro populations were found in both artificial ecotopes and the wild, while the mel anica population was collected only in the wild. Isoenzymatic analysis detected phenotypic and genetic differences among them, with the melânica population being the most distinct. The brasiliensis population is the most important one from an epidemiological point of view, with the widest geographic distribution, the highest Trypanosoma cruzi infection rate, and occupying a wide variety of ecotopes.

  13. The Botanical Monoterpenes Linalool and Eugenol Flush-Out Nymphs of Triatoma infestans (Hemiptera: Reduviidae).

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    Moretti, A N; Seccacini, E A; Zerba, E N; Canale, D; Alzogaray, R A

    2017-09-01

    Monoterpenes are the main components of essential oils. Some members of this chemical family present insecticidal activity. Triatoma infestans (Klug) is the main vector of Chagas disease in Argentina, Bolivia, Paraguay, and Perú. The objective of this work was to evaluate the effect of six monoterpenes (1,8-cineole, eugenol, linalool, menthol, α-terpineol, and thymol) on the locomotor and flushing out activity of T. infestans. A video tracking technique was used to evaluate the locomotor activity of nymphs exposed to different concentrations of these chemicals applied as films on filter paper. Papers treated with acetone alone were used as negative controls, while solutions of tetramethrin were applied as positive controls. Only linalool and menthol produced hyperactivation. Flushing out was assessed under laboratory conditions using a standardized aerosolization method. All monoterpenes were applied at 1.5 g/m3. 1,8-Cineole, α-terpineol, and thymol flushed out 10% or less nymphs. The average flushing out produced by eugenol was 36.7%. Values of median flushing out time (FT50) could only be calculated for linalool and menthol (16.67 and 42.98 min, respectively). The FT50 value for the positive control tetramethrin (applied at 0.006 g/m3) was 8.29 min. Following these results, the flushing out activity of a mixture of linalool and eugenol was evaluated. The FT50 of this 2:1 linalool:eugenol mixture was 40.73 min. Finally, flushing out assays performed in semifield conditions showed similar results to those obtained at the laboratory. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Atividade de Voo de Rhodnius robustus Larrousse em Laboratório (Hemiptera:Reduviidae.

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    Dayse Rocha

    2014-04-01

    Abstract. Rhodnius robustus Larrousse, is a sylvatic species found in northern Brazil (Acre, Amazonas and Pará, Guyana, Bolivia, Colombia, Ecuador, Peru and Venezuela. This species has been found in and around the dwellings, have been data collection of this species naturally infected with Trypanossoma cruzi Chagas, Trypanossoma rangeli Tejera and mixed infections. From observations made in the laboratory, we evaluated the ability of flight, correlating this activity with the amount of ingested blood, sex and fasting period. Despite the high temperature (33º C, 26% of the insects flew suggesting the influence of intrinsic factors in flight capacity of R. robustus.

  15. Feeding and defaecation behaviour of Triatoma patagonica (Del Ponte, 1929 (Hemiptera: Reduviidae

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    Julieta Nattero

    2002-10-01

    Full Text Available Among the vectors of Chagas disease, Triatoma patagonica is a species in the process of adaptation to the human environment being recently registered in urban and suburban zones. However, its importance as a vector of Chagas disease is unknown. The aim of this work was to evaluate two aspects of vectorial competence: the feeding behaviour and the defaecation pattern. These processes were studied in females of T. patagonica fed ad libitum on a restrained pigeon. The results showed that the blood meal size was negatively correlated with the time of first defaecation (r = -0.42. The first defaecation was emitted before the first 10 min and defaecations during feeding were frequent. A total of 73% of females, defaecated during the first 30 min post-feeding. These results suggest that if this species subsequently colonizes the domicile, it would be capable of transmitting Trypanosoma cruzi.

  16. Estudio del sistema ocelar de la Vinchuca Triatoma infestans (Klug, 1834) (Heteroptera: Reduviidae)

    OpenAIRE

    Insausti, Teresita Concepción

    1997-01-01

    Mediante técnicas de microscopía óptica, electrónica de transmisión y electrónica de barrido y de inyección intraneural de colorantes, se estudió la morfología, ultraestructura, desarrollo postembrionario y conexiones nerviosas de los ocelos de T. infestans, así como su adaptación a la luz-oscuridad. pudo constatarse que estos órganos exhiben un nivel de complejidad no descripto para otros insectos. El rabdoma retinular involucra todas las caras laterales de las células fotorreceptoras. Se ob...

  17. Immune homeostasis to microorganisms in the guts of triatomines (Reduviidae): a review

    OpenAIRE

    Garcia, Eloi S; Castro, Daniele P; Figueiredo, Marcela B; Azambuja, Patrícia

    2010-01-01

    Bacteria, fungi and parasites are in constant contact with the insect gut environment and can influence different aspects of the host gut physiology. Usually, some of these microorganisms develop and survive in the digestive tract. Therefore, the gut environment must be able to tolerate certain populations of these organisms for the establishment of interactions between non-pathogenic bacteria, parasites and the gut. This review provides a brief overview of the biological and molecular mechan...

  18. Immune homeostasis to microorganisms in the guts of triatomines (Reduviidae: a review

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    Eloi S Garcia

    2010-08-01

    Full Text Available Bacteria, fungi and parasites are in constant contact with the insect gut environment and can influence different aspects of the host gut physiology. Usually, some of these microorganisms develop and survive in the digestive tract. Therefore, the gut environment must be able to tolerate certain populations of these organisms for the establishment of interactions between non-pathogenic bacteria, parasites and the gut. This review provides a brief overview of the biological and molecular mechanisms that microorganisms use to interact with the gut epithelia in mosquitoes and speculates on their significances for the development of bacteria and Trypanosoma cruzi in the guts of triatomines.

  19. Immune homeostasis to microorganisms in the guts of triatomines (Reduviidae)--a review.

    Science.gov (United States)

    Garcia, Eloi S; Castro, Daniele P; Figueiredo, Marcela B; Azambuja, Patrícia

    2010-08-01

    Bacteria, fungi and parasites are in constant contact with the insect gut environment and can influence different aspects of the host gut physiology. Usually, some of these microorganisms develop and survive in the digestive tract. Therefore, the gut environment must be able to tolerate certain populations of these organisms for the establishment of interactions between non-pathogenic bacteria, parasites and the gut. This review provides a brief overview of the biological and molecular mechanisms that microorganisms use to interact with the gut epithelia in mosquitoes and speculates on their significances for the development of bacteria and Trypanosoma cruzi in the guts of triatomines.

  20. Triatoma mexicana (Hemiptera: Reduviidae) in Guanajuato, Mexico: house infestation and seasonal variation.

    Science.gov (United States)

    Salazar Schettino, Paz María; Rosales Piña, José Santiago; Rojas Wastavino, Gloria; Cabrera Bravo, Margarita; Vences Blanco, Mauro; López Cárdenas, Jorge

    2007-11-01

    Triatoma mexicana was described by Herrich-Schaeffer in 1848. In 1940, a male specimen was found in Hidalgo. In 1970, this species was recorded in the state of Queretaro. Later, it was registered in Guanajuato and San Luis Potosi. In the present paper we performed an investigation in 545 dwellings from three counties in the state of Guanajuato, Mexico, from March 2003 to May 2004. The search and capture of triatomines were seasonally performed indoors and outdoors. Entomological indexes were calculated. The risk and no risk relations between triatomine presence and housing construction materials were analyzed. Fourteen triatomines were collected indoors and 151 outdoors. The vectors were collected in houses built with either risky and non-risky materials. Adults go indoors but do not settle there, hence, no relationship was found between the building materials and infestation of houses. Conventional interventions like house improvement or insecticide spraying are not efficient for the control of T. mexicana, because its developmental cycle is accomplished outdoors in the area surrounding the houses.

  1. First finding of melanic sylvatic Triatoma infestans (Hemiptera: Reduviidae) colonies in the Argentine Chaco.

    Science.gov (United States)

    Ceballos, L A; Piccinali, R V; Berkunsky, I; Kitron, U; Gürtler, R E

    2009-09-01

    Triatoma infestans (Klug), the most important vector of Chagas disease in southern South America, is a highly domiciliated species with well-known sylvatic foci only in the Bolivian Andean valleys and in the Bolivian Chaco, where melanic insects designated as "dark morphs" were found. After the tentative identification of two melanic bugs collected from parrot nests in a forest reserve in the Argentine Chaco as T. infestans, we conducted an intensive search there using mouse-baited sticky traps in summer 2006 and 2007. Four live T. infestans bugs were collected in trees without parrot nests in 288 trap-nights, whereas no bug was collected from inside trees with active parrot nests in 51 trap-nights. To increase bug captures, hollow tree trunks that recently had had Amazona aestiva (Berlepsch) and Aratinga acuticaudata (Vieillot) parrot nests were treated with insecticide fumigant canisters exhibiting strong knockdown power. Four (22%) of 18 trees were positive for T. infestans with a dark phenotype. A fragment of the mitochondrial gene COI of 8 of the 14 triatomine bugs collected was successfully sequenced and confirmed as T. infestans. Most of the bugs were captured from Aspidosperma quebracho-blanco (Schlechter) hollow tree trunks harboring parrot nests. All of the T. infestans collected from the nearest house located at 10 km from the sylvatic foci displayed normal chromatic characters. The repeated finding of T. infestans in sylvatic habitats, albeit at very low density, shows that this species is capable of maintaining viable sylvatic foci in the absence of human hosts and immigration from domestic populations. These are the first confirmed findings of sylvatic T. infestans colonies in Argentina and of dark morphs in the Argentine Chaco.

  2. Vital Statistics of Panstrongylus geniculatus (Latreille 1811 (Hemiptera: Reduviidae under Experimental Conditions

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    Cabello Daniel R

    1998-01-01

    Full Text Available A statistical evaluation of the population dynamics of Panstrongylus geniculatus is based on a cohort experiment conducted under controlled laboratory conditions. Animals were fed on hen every 15 days. Egg incubation took 21 days; mean duration of 1st, 2nd, 3rd, 4th, and 5th instar nymphs was 25, 30, 58, 62, and 67 days, respectively; mean nymphal development time was 39 weeks and adult longevity was 72 weeks. Females reproduced during 30 weeks, producing an average of 61.6 eggs for female on its lifetime; the average number of eggs/female/week was 2.1. Total number of eggs produced by the cohort was 1379. Average hatch for the cohort was 88.9%; it was not affected by age of the mother. Age specific survival and reproduction tables were constructed. The following population parameters were evaluated, generation time was 36.1 weeks; net reproduction rate was 89.4; intrinsic rate of natural increase was 0.125; instantaneous birth and death rates were 0.163 and 0.039 respectively; finite rate of increase was 1.13; total reproductive value was 1196 and stable age distribution was 31.2% eggs, 64.7% nymphs and 4.1% adults. Finally the population characteristics of P. geniculatus lead to the conclusion that this species is a K strategist.

  3. Flight metabolism in Panstrongylus megistus (Hemiptera: Reduviidae: the role of carbohydrates and lipids

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    Lilián E Canavoso

    2003-10-01

    Full Text Available The metabolism of lipids and carbohydrates related to flight activity in Panstrongylus megistus was investigated. Insects were subjected to different times of flight under laboratory conditions and changes in total lipids, lipophorin density and carbohydrates were followed in the hemolymph. Lipids and glycogen were also assayed in fat body and flight muscle. In resting insects, hemolymph lipids averaged 3.4 mg/ml and significantly increased after 45 min of flight (8.8 mg/ml, P < 0.001. High-density lipophorin was the sole lipoprotein observed in resting animals. A second fraction with lower density corresponding to low-density lipophorin appeared in insects subjected to flight. Particles from both fractions showed significant differences in diacylglycerol content and size. In resting insects, carbohydrate levels averaged 0.52 mg/ml. They sharply declined more than twofold after 15 min of flight, being undetectable in hemolymph of insects flown for 45 min. Lipid and glycogen from fat body and flight muscle decreased significantly after 45 min of flight. Taken together, the results indicate that P. megistus uses carbohydrates during the initiation of the flight after which, switching fuel for flight from carbohydrates to lipids.

  4. Flight metabolism in Panstrongylus megistus (Hemiptera: Reduviidae): the role of carbohydrates and lipids

    OpenAIRE

    Canavoso,Lilián E; Stariolo,Raúl; Rubiolo,Edilberto R

    2003-01-01

    The metabolism of lipids and carbohydrates related to flight activity in Panstrongylus megistus was investigated. Insects were subjected to different times of flight under laboratory conditions and changes in total lipids, lipophorin density and carbohydrates were followed in the hemolymph. Lipids and glycogen were also assayed in fat body and flight muscle. In resting insects, hemolymph lipids averaged 3.4 mg/ml and significantly increased after 45 min of flight (8.8 mg/ml, P < 0.001). High-...

  5. Triatoma mexicana (Hemiptera: Reduviidae in Guanajuato, Mexico: house infestation and seasonal variation

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    Paz María Salazar Schettino

    2007-11-01

    Full Text Available Triatoma mexicana was described by Herrich-Schaeffer in 1848. In 1940, a male specimen was found in Hidalgo. In 1970, this species was recorded in the state of Queretaro. Later, it was registered in Guanajuato and San Luis Potosi. In the present paper we performed an investigation in 545 dwellings from three counties in the state of Guanajuato, Mexico, from March 2003 to May 2004. The search and capture of triatomines were seasonally performed indoors and outdoors. Entomological indexes were calculated. The risk and no risk relations between triatomine presence and housing construction materials were analyzed. Fourteen triatomines were collected indoors and 151 outdoors. The vectors were collected in houses built with either risky and non-risky materials. Adults go indoors but do not settle there, hence, no relationship was found between the building materials and infestation of houses. Conventional interventions like house improvement or insecticide spraying are not efficient for the control of T. mexicana, because its developmental cycle is accomplished outdoors in the area surrounding the houses.

  6. Incoordination, Paralysis and Recovery after Pyrethroid Treatment on Nymphs III of Triatoma infestans (Hemiptera: Reduviidae

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    Raúl A Alzogaray

    1997-05-01

    Full Text Available Symptoms of poisoning for deltamethrin and cis-permethrin on nymphs III of Triatoma infestans were described. The time required for incoordination and paralysis were determined. Deltamethrin was equal or more rapid in the onset of the first effect (accordingly to dose, and cis-permethrin in the onset of the second one. There were no significant differences between incoordination doses 50% (IncD50s at different times for the two pyrethroids. They showed equivalent incoordination power, but the nymphs treated with deltamethrin recovered slightly more rapid and in greater amount than the nymphs treated with cis-permethrin. The recovery was inhibited by the simultaneus application of piperonyl butoxide. This result suggests that biotransformation by mixed-function microsomal oxidases are involved in the process of recovery

  7. Experimental evaluation of insecticidal paints against Triatoma infestans (Hemiptera: Reduviidae), under natural climatic conditions

    OpenAIRE

    Amelotti, Ivana; Catal?, Silvia S; Gorla, David E

    2009-01-01

    Abstract Background Triatoma infestans is the main vector of Chagas disease in the Gran Chaco region of South America. The traditional spraying technique used for the application of pyrethroid insecticides has shown low efficiency in the elimination of the vector species populations occupying peridomestic structures of rural houses in the endemic area of Argentina. As part of studies looking for better alternatives, we evaluated the residual effect of insecticidal paints on the mortality of f...

  8. Experimental evaluation of insecticidal paints against Triatoma infestans (Hemiptera: Reduviidae), under natural climatic conditions.

    Science.gov (United States)

    Amelotti, Ivana; Catalá, Silvia S; Gorla, David E

    2009-07-08

    Triatoma infestans is the main vector of Chagas disease in the Gran Chaco region of South America. The traditional spraying technique used for the application of pyrethroid insecticides has shown low efficiency in the elimination of the vector species populations occupying peridomestic structures of rural houses in the endemic area of Argentina. As part of studies looking for better alternatives, we evaluated the residual effect of insecticidal paints on the mortality of fourth instar nymphs of T. infestans. The study was based on an experimental design that included two groups treated with an organophosphate (Inesfly 5A IGR) and a pyrethroid (Inesfly 5A IGR NG) formulations of the paint, that were applied on wood, cement blocks and adobe bricks under natural climatic conditions. A third group was an untreated control. Both paint formulations showed very long residual activity, producing mortality of 84% and 98% (pyrethroid and organophosphate formulations, respectively) after 12 months of the paint application. After eight months, nymphs exposed during 6 hours to the painted surfaces with the pyrethroid and organophosphate formulations showed 81.33% and 100% mortality, respectively. The organophosphate- and pyrethroid-based insecticidal paints showed a very long residual activity on the mortality of fourth instar nymphs of T infestans, compared with the traditional spraying technique used for the application of pyrethroid insecticides in peridomestic structures of rural houses in the endemic region for Chagas disease in the Gran Chaco of Argentina. The application of the paints by trained personnel of the vector control programmes could be considered as an alternative control tool in areas where the traditional methods have failed or showed low efficacy.

  9. Experimental evaluation of insecticidal paints against Triatoma infestans (Hemiptera: Reduviidae, under natural climatic conditions

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    Gorla David E

    2009-07-01

    Full Text Available Abstract Background Triatoma infestans is the main vector of Chagas disease in the Gran Chaco region of South America. The traditional spraying technique used for the application of pyrethroid insecticides has shown low efficiency in the elimination of the vector species populations occupying peridomestic structures of rural houses in the endemic area of Argentina. As part of studies looking for better alternatives, we evaluated the residual effect of insecticidal paints on the mortality of fourth instar nymphs of T. infestans. Results The study was based on an experimental design that included two groups treated with an organophosphate (Inesfly 5A IGR™ and a pyrethroid (Inesfly 5A IGR NG™ formulations of the paint, that were applied on wood, cement blocks and adobe bricks under natural climatic conditions. A third group was an untreated control. Both paint formulations showed very long residual activity, producing mortality of 84% and 98% (pyrethroid and organophosphate formulations, respectively after 12 months of the paint application. After eight months, nymphs exposed during 6 hours to the painted surfaces with the pyrethroid and organophosphate formulations showed 81.33% and 100% mortality, respectively. Conclusion The organophosphate- and pyrethroid-based insecticidal paints showed a very long residual activity on the mortality of fourth instar nymphs of T infestans, compared with the traditional spraying technique used for the application of pyrethroid insecticides in peridomestic structures of rural houses in the endemic region for Chagas disease in the Gran Chaco of Argentina. The application of the paints by trained personnel of the vector control programmes could be considered as an alternative control tool in areas where the traditional methods have failed or showed low efficacy.

  10. Cuticular hydrocarbons of Triatoma dimidiata (Hemiptera: Reduviidae): intraspecific variation and chemotaxonomy.

    Science.gov (United States)

    Calderón-Fernández, Gustavo M; Girotti, Juan R; Juárez, M Patricia

    2011-03-01

    Triatoma dimidiata Latreille is a major vector of Chagas disease with an extensive geographic distribution from Central Mexico, through Central America, to northern South America. As a result of its variability in phenetic and genetic characters, disagreement concerning its taxonomic status has been raised. In this study, the cuticular hydrocarbon pattern of T. dimidiata populations from Mexico, Belize, Guatemala, Honduras, Costa Rica, and Colombia was analyzed by capillary gas chromatography coupled to mass spectrometry; linear discriminant analysis was used to help elucidate population structure. Vector populations segregated into five distinct groups; specimens from Yucatan Peninsula, together with those from Central Mexico, Central America, and Colombia corresponded to different T. dimidiata subspecies, a putative different species comprising insects from Belize, together with an isolated population collected at bat caves in Guatemala. The analysis revalidates the earlier division of T dimidiata into three subspecies, T. d. maculipennis, T. d. dimidiata, and T. d. capitata; and an additional subspecies and a distinct species are proposed.

  11. Geographic Distribution and Ecology of Triatoma dimidiata (Hemiptera: Reduviidae) in Colombia.

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    Parra-Henao, Gabriel; Angulo, Víctor Manuel; Osorio, Lisardo; Jaramillo-O, Nicolás

    2016-01-01

    Triatoma dimidiata Latreille is the second most important vector of Chagas' disease in Colombia and is found in urban and periurban areas. From January 2007 to June 2008, we performed field work in 8 departments, 18 municipalities, and 44 rural villages, covering most of its known distribution and all of its ecological zones in the country. The goal was to determine the geographical distribution, the ecology, and house infestation indices of T. dimidiata over its range and hence the Chagas' disease transmission risk. In Colombia, T. dimidiata occupies a wide variety of ecosystems, from transformed ecosystems in the Andean biome with shrub and xerofitic vegetation to very dense forests in the humid tropical forests in the Sierra Nevada of Santa Marta. According to genetic and ecological criteria, at least two T. dimidiata forms of this species are present: populations from the northwest of the country (Caribbean plains) are restricted to palm tree habitats, and domestic involvement is limited to sporadic visits because of attraction by light; and populations of the east region (Andean mountains) presenting a complex distributional pattern including sylvatic, peridomestic, and domiciliated ecotopes, and occupying a great variety of life zones. The latter population is of epidemiological importance due to the demonstrated migration and genetical flow of individuals among the different habitats. Control, therefore, must take into account its diversity of habitats. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Towards a phylogenetic approach to the composition of species complexes in the North and Central American Triatoma, vectors of Chagas disease.

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    de la Rúa, Nicholas M; Bustamante, Dulce M; Menes, Marianela; Stevens, Lori; Monroy, Carlota; Kilpatrick, C William; Rizzo, Donna; Klotz, Stephen A; Schmidt, Justin; Axen, Heather J; Dorn, Patricia L

    2014-06-01

    Phylogenetic relationships of insect vectors of parasitic diseases are important for understanding the evolution of epidemiologically relevant traits, and may be useful in vector control. The sub-family Triatominae (Hemiptera:Reduviidae) includes ∼140 extant species arranged in five tribes comprised of 15 genera. The genus Triatoma is the most species-rich and contains important vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Triatoma species were grouped into complexes originally by morphology and more recently with the addition of information from molecular phylogenetics (the four-complex hypothesis); however, without a strict adherence to monophyly. To date, the validity of proposed species complexes has not been tested by statistical tests of topology. The goal of this study was to clarify the systematics of 19 Triatoma species from North and Central America. We inferred their evolutionary relatedness using two independent data sets: the complete nuclear internal transcribed spacer-2 ribosomal DNA (ITS-2 rDNA) and head morphometrics. In addition, we used the Shimodaira-Hasegawa statistical test of topology to assess the fit of the data to a set of competing systematic hypotheses (topologies). An unconstrained topology inferred from the ITS-2 data was compared to topologies constrained based on the four-complex hypothesis or one inferred from our morphometry results. The unconstrained topology represents a statistically significant better fit of the molecular data than either the four-complex or the morphometric topology. We propose an update to the composition of species complexes in the North and Central American Triatoma, based on a phylogeny inferred from ITS-2 as a first step towards updating the phylogeny of the complexes based on monophyly and statistical tests of topologies. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Does Triatoma brasiliensis occupy the same environmental niche space as Triatoma melanica?

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    de Souza, Rita de Cássia Moreira; Campolina-Silva, Gabriel H; Bezerra, Claudia Mendonça; Diotaiuti, Liléia; Gorla, David E

    2015-07-10

    Triatomines (Hemiptera, Reduviidae) are vectors of Trypanosoma cruzi, the causative agent of Chagas disease, one of the most important vector-borne diseases in Latin America. This study compares the environmental niche spaces of Triatoma brasiliensis and Triatoma melanica using ecological niche modelling and reports findings on DNA barcoding and wing geometric morphometrics as tools for the identification of these species. We compared the geographic distribution of the species using generalized linear models fitted to elevation and current data on land surface temperature, vegetation cover and rainfall recorded by earth observation satellites for northeastern Brazil. Additionally, we evaluated nucleotide sequence data from the barcode region of the mitochondrial cytochrome c oxidase subunit I (CO1) and wing geometric morphometrics as taxonomic identification tools for T. brasiliensis and T. melanica. The ecological niche models show that the environmental spaces currently occupied by T. brasiliensis and T. melanica are similar although not equivalent, and associated with the caatinga ecosystem. The CO1 sequence analyses based on pair wise genetic distance matrix calculated using Kimura 2-Parameter (K2P) evolutionary model, clearly separate the two species, supporting the barcoding gap. Wing size and shape analyses based on seven landmarks of 72 field specimens confirmed consistent differences between T. brasiliensis and T. melanica. Our results suggest that the separation of the two species should be attributed to a factor that does not include the current environmental conditions. However, as the caatinga is a biome that has existed in the area for at least the last 18,000 years, past conditions might have had an influence in the speciation process. The DNA Barcoding approach may be extended to these members of the subfamily Triatominae.

  14. Projected future distributions of vectors of Trypanosoma cruzi in North America under climate change scenarios.

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    Miroslava Garza

    2014-05-01

    Full Text Available Chagas disease kills approximately 45 thousand people annually and affects 10 million people in Latin America and the southern United States. The parasite that causes the disease, Trypanosoma cruzi, can be transmitted by insects of the family Reduviidae, subfamily Triatominae. Any study that attempts to evaluate risk for Chagas disease must focus on the ecology and biogeography of these vectors. Expected distributional shifts of vector species due to climate change are likely to alter spatial patterns of risk of Chagas disease, presumably through northward expansion of high risk areas in North America.We forecast the future (2050 distributions in North America of Triatoma gerstaeckeri and T. sanguisuga, two of the most common triatomine species and important vectors of Trypanosoma cruzi in the southern United States. Our aim was to analyze how climate change might affect the future shift of Chagas disease in North America using a maximum entropy algorithm to predict changes in suitable habitat based on vector occurrence points and predictive environmental variables. Projections based on three different general circulation models (CCCMA, CSIRO, and HADCM3 and two IPCC scenarios (A2 and B2 were analyzed. Twenty models were developed for each case and evaluated via cross-validation. The final model averages result from all twenty of these models. All models had AUC >0.90, which indicates that the models are robust. Our results predict a potential northern shift in the distribution of T. gerstaeckeri and a northern and southern distributional shift of T. sanguisuga from its current range due to climate change.The results of this study provide baseline information for monitoring the northward shift of potential risk from Chagas disease in the face of climate change.

  15. Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.

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    Frédéric Menu

    2010-05-01

    Full Text Available The developmental time of vector insects is important in population dynamics, evolutionary biology, epidemiology and in their responses to global climatic change. In the triatomines (Triatominae, Reduviidae, vectors of Chagas disease, evolutionary ecology concepts, which may allow for a better understanding of their biology, have not been applied. Despite delay in the molting in some individuals observed in triatomines, no effort was made to explain this variability.We applied four methods: (1 an e-mail survey sent to 30 researchers with experience in triatomines, (2 a statistical description of the developmental time of eleven triatomine species, (3 a relationship between development time pattern and climatic inter-annual variability, (4 a mathematical optimization model of evolution of developmental delay (diapause.85.6% of responses informed on prolonged developmental times in 5(th instar nymphs, with 20 species identified with remarkable developmental delays. The developmental time analysis showed some degree of bi-modal pattern of the development time of the 5(th instars in nine out of eleven species but no trend between development time pattern and climatic inter-annual variability was observed. Our optimization model predicts that the developmental delays could be due to an adaptive risk-spreading diapause strategy, only if survival throughout the diapause period and the probability of random occurrence of "bad" environmental conditions are sufficiently high.Developmental delay may not be a simple non-adaptive phenotypic plasticity in development time, and could be a form of adaptive diapause associated to a physiological mechanism related to the postponement of the initiation of reproduction, as an adaptation to environmental stochasticity through a spreading of risk (bet-hedging strategy. We identify a series of parameters that can be measured in the field and laboratory to test this hypothesis. The importance of these findings is

  16. Adaptive Developmental Delay in Chagas Disease Vectors: An Evolutionary Ecology Approach

    Science.gov (United States)

    Menu, Frédéric; Ginoux, Marine; Rajon, Etienne; Lazzari, Claudio R.; Rabinovich, Jorge E.

    2010-01-01

    Background The developmental time of vector insects is important in population dynamics, evolutionary biology, epidemiology and in their responses to global climatic change. In the triatomines (Triatominae, Reduviidae), vectors of Chagas disease, evolutionary ecology concepts, which may allow for a better understanding of their biology, have not been applied. Despite delay in the molting in some individuals observed in triatomines, no effort was made to explain this variability. Methodology We applied four methods: (1) an e-mail survey sent to 30 researchers with experience in triatomines, (2) a statistical description of the developmental time of eleven triatomine species, (3) a relationship between development time pattern and climatic inter-annual variability, (4) a mathematical optimization model of evolution of developmental delay (diapause). Principal Findings 85.6% of responses informed on prolonged developmental times in 5th instar nymphs, with 20 species identified with remarkable developmental delays. The developmental time analysis showed some degree of bi-modal pattern of the development time of the 5th instars in nine out of eleven species but no trend between development time pattern and climatic inter-annual variability was observed. Our optimization model predicts that the developmental delays could be due to an adaptive risk-spreading diapause strategy, only if survival throughout the diapause period and the probability of random occurrence of “bad” environmental conditions are sufficiently high. Conclusions/Significance Developmental delay may not be a simple non-adaptive phenotypic plasticity in development time, and could be a form of adaptive diapause associated to a physiological mechanism related to the postponement of the initiation of reproduction, as an adaptation to environmental stochasticity through a spreading of risk (bet-hedging) strategy. We identify a series of parameters that can be measured in the field and laboratory to test

  17. Evidenciação de antígeno da hepatite B (HBsAg em "manchas" obtidas de exemplares de Triatominae: nota prévia Hepatitis B antigen (HBsAg in wildcaught Triatominae in Brazil: communication

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    J. A. N. Candeias

    1976-09-01

    Full Text Available De 890 "manchas" provenientes de insetos dos gêneros Panstrongylus, Rhodnius e Triatoma, positivas para sangue humano, 7 deram resultados presumptivamente positivos por hemaglutinação passiva para HBsAg. Deste total só um caso foi confirmado como positivo, por RIE (radioimunoensaio, correspondendo a uma "mancha" obtida de Triatoma sordida (ninfa de 5.º estádio.A total of 890 impressions on filter paper identified as containing human blood, were examined for the presence of hepatitis B antigen (HBsAg, using the Hepanosticon haemagglutination and radioimmunoassay techniques. The samples examined belong to the Panstrongylus, Rhodnius and Triatoma genres. The Hepanosticon haemagglutination technique showed that 7 impressions, after elution, were presumably positive for HBsAg, but by radioimmunoassay, this antigen could only be detected in 1. The positive sample was obtained from a specimen of Triatoma sordida (fifth instar nymph.

  18. Biologia do triatoma vitticeps (Stal, 1859 em condiçoes de laboratórios (Hemiptera: Reduvidae: Triatominae I. Ciclo evolutivo Biology of triatoma vitticeps (Stal, 1859 under laboratory conditions (Hemiptera: Reduvidae: Triatominae: I. Evolutive cycle

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    Teresa Cristina M. Gonçalves

    1988-12-01

    Full Text Available Foram feitas observações do ciclo evolutivo do Triatoma vitticeps com alimentação semanal em camundongo, em condições de laboratório. De quatro casais virgens obtiveram-se 435 ovos, sendo que 149 destinaram-se ao ciclo evolutivo e 286 ao estudo da resistência ao jejum, o que constituirá a segunda etapa deste trabalho. Apenas 50 exemplares atingiram a fase adulta num período X (S = 270 ± 45 dias. Quanto ao tempo de incubação, o 1° e o 2° estádios foram realizados, cada um, em menos de um mês, enquanto que os 3º, 4º e 5º estádios requereram cerca de um, dois e três meses, respectivamente. A procura pelo 1º repasto ocorreu de forma sensível no 3º, 6º e 10º dias. Em todos os estádios, mais de 50% dos exemplares realizaram apenas um repasto, com exceção do 5º, onde foram necessários dois. No que diz respeito ao intervalo de tempo entre o oferecimento do repasto, o ato de picar, e a duração do repasto, observou-se que estes aumentaram gradativamente de acordo com o estádio. Dos 423 repastos realizados, 390 não foram seguidos de defecação no prazo de 10 min. Sob este aspecto parece que o T. vitticeps não é um bom transmissor do T. cruzi. O experimento teve a duração de 13 meses e neste período as temperaturas máximas e mínimas e a umidade relativa do ar variaram em média de 28 ± 2°C a 25 ± 2°C e 80 ± 2%, respectivamente. O material é proveniente da criação mantida no Departamento de entomologia do Instituto Oswaldo Cruz.Observations were made on the evolutive cycle of Triatoma vitticeps, held under laboratory conditions and fed weekly in mice. Of the 435 eggs obtained, from 4 virgen couples, 149 were purposed for the biological cycle study and 286 to evaluate their resistance to starvation, which shall be a second part of this work. Only 50 specimens reached the adult stage in a period of X (S = 270 ± 45 days. At the incubation time, the first and second instars were of less than a month for each, while the third, fourth and fifth instars requires approximately one, two and three months, respectively. The search for the first meal occured clearly on the 3rd, 6th and 10th day. During all the stages,more than 50% of the specimens had only one blood-meal, except the fifth one, when two blood-meals were required. In relation to the time-lapse between the presenting of the blood-meal and the beginning of feeding, as well as the length of the blood-meal, it was observed that these increased gradually according to the stage. From the 423 blood-meals performed, 390 were not followed by defecation in the settled period of 10 min. Under this point of view, t. vitticeps seems to be a poor transmissor of T. cruzi. The experiment was carried out for 13 months and by this time the averages of minimum and maximum temperatures and the humidity were 25 ± 2°C - 28 ± 2°C and 80 ± 2%, respectively. The material belongs to the triatomine colony held at the Oswaldo Cruz Institute, Department of Entomology.

  19. Attraction of Chagas disease vectors (Triatominae) to artificial light sources in the canopy of primary Amazon rainforest.

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    Castro, Marcelo C M; Barrett, Toby V; Santos, Walter S; Abad-Franch, Fernando; Rafael, José A

    2010-12-01

    Adult triatomines occasionally fly into artificially lit premises in Amazonia. This can result in Trypanosoma cruzi transmission to humans either by direct contact or via foodstuff contamination, but the frequency of such behaviour has not been quantified. To address this issue, a light-trap was set 45 m above ground in primary rainforest near Manaus, state of Amazonas, Brazil and operated monthly for three consecutive nights over the course of one year (432 trap-hours). The most commonly caught reduviids were triatomines, including 38 Panstrongylus geniculatus, nine Panstrongylus lignarius, three Panstrongylus rufotuberculatus, five Rhodnius robustus, two Rhodnius pictipes, one Rhodnius amazonicus and 17 Eratyrus mucronatus. Males were collected more frequently than females. The only month without any catches was May. Attraction of most of the known local T. cruzi vectors to artificial light sources is common and year-round in the Amazon rainforest, implying that they may often invade premises built near forest edges and thus become involved in disease transmission. Consequently, effective Chagas disease prevention in Amazonia will require integrating entomological surveillance with the currently used epidemiological surveillance.

  20. Attraction of Chagas disease vectors (Triatominae to artificial light sources in the canopy of primary Amazon rainforest

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    Marcelo CM Castro

    2010-12-01

    Full Text Available Adult triatomines occasionally fly into artificially lit premises in Amazonia. This can result in Trypanosoma cruzi transmission to humans either by direct contact or via foodstuff contamination, but the frequency of such behaviour has not been quantified. To address this issue, a light-trap was set 45 m above ground in primary rainforest near Manaus, state of Amazonas, Brazil and operated monthly for three consecutive nights over the course of one year (432 trap-hours. The most commonly caught reduviids were triatomines, including 38 Panstrongylus geniculatus, nine Panstrongylus lignarius, three Panstrongylus rufotuberculatus, five Rhodnius robustus, two Rhodnius pictipes, one Rhodnius amazonicus and 17 Eratyrus mucronatus. Males were collected more frequently than females. The only month without any catches was May. Attraction of most of the known local T. cruzi vectors to artificial light sources is common and year-round in the Amazon rainforest, implying that they may often invade premises built near forest edges and thus become involved in disease transmission. Consequently, effective Chagas disease prevention in Amazonia will require integrating entomological surveillance with the currently used epidemiological surveillance.

  1. Cytogenetic analysis of Triatoma pseudomaculata Corrêa and Espínola, 1964 (Hemiptera, Triatominae) from different Brazilian states.

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    Imperador, C H L; Alevi, K C C; Oliveira, J; Rosa, J A; Azeredo-Oliveira, M T V

    2016-03-31

    Triatoma maculata and T. pseudomaculata are allopatric; however, it is believed that T. maculata was introduced into the Brazilian northeast by passive transportation of the nymphs between the feathers of migratory birds, followed by the speciation of T. pseudomaculata. T. pseudomaculata is the second most epidemiologically important species in the northeast of Brazil after T. brasiliensis. Therefore, given the broad range of T. pseudomaculata, the objective of the present study was to cytogenetically analyze different populations of T. pseudomaculata from different Brazilian states in order to investigate possible intraspecific chromosomal variation between them. Three adult T. pseudomaculata males from each population (Pernambuco, Ceará, Paraíba, Bahia, Rio Grande do Norte, and Piauí) were analyzed by lacto-acetic orcein and C-banding. All of the specimens analyzed exhibited the same cytogenetic characteristics, i.e., 22 chromosomes (20 autosomes and XY), a chromocenter formed by the X and Y sex chromosomes and one pair of autosomes, and heterochromatin blocks in three or four pairs of autosomes. These data confirm that all of the populations analyzed were T. pseudomaculata, and although they may be subject to different selection pressures they have maintained the genetic integrity that characterizes the species.

  2. La aerotermia como alternativa para el control de Triatoma infestans (Hemiptera, Reduviidae resistentes a deltametrina Air temperature elevation as an alternative for the control of deltamethrin-resistant Triatoma infestans (Hemiptera, Reduviidae

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    Alberto G. Gentile

    2004-08-01

    Full Text Available Se exploraron los efectos de la elevación artificial de la temperatura del aire sobre las formas embrionarias, ninfales y adultas de Triatoma infestansresistentes a Deltametrina. En laboratorio, se expuso a temperaturas crecientes del aire la progenie completa de T. infestans, para determinar viabilidad de huevos y supervivencia en ninfas y adultos; sobre el terreno, la experimentación se llevó a cabo en una vivienda tipo rancho previamente evaluada como colonizada. Durante la fase de laboratorio se comprobó la inviabilidad del 100% de los huevos y la mortalidad del 100% de las ninfas y adultos expuestos a temperaturas del aire estanco de entre 45ºC y 55ºC, mientras que en la fase de terreno se logró reproducir el efecto ovicida del calor, como así también la negativización de las evaluaciones entomológicas de la vivienda de experimentación, llevadas a cabo a las 72 horas, a los 30, 60 y 90 días. La elevación artificial de la temperatura del aire estanco en las habitaciones resultó ser un método de control de eficacia aceptable, inocuo y técnicamente sencillo.This study explores the effects of artificial air temperature elevation on the embryonic, nymphal, and adult forms of deltamethrin-resistant Triatoma infestans. In the laboratory, complete offspring of T. infestanswere exposed to increasing air temperatures to determine the viability of eggs and survival of nymphs and adults; in the field, the experiment was conducted in a poor rural dwelling previously identified as infested with the vector. The laboratory phase showed 100% non-viability of eggs and 100% mortality of nymphs and adults exposed to airtight temperatures from 45ºC to 55ºC, while the field phase succeeded in reproducing the heat's ovicidal effect and negative conversion of entomological assays in the experimental dwelling, as conducted over the course of 72 hours at 30, 60, and 90 days from the baseline evaluation. Artificial elevation of airtight temperature on dwellings proved to be an acceptable, harmless, and technically simple control method.

  3. Detección de triatominos (Hemiptera: Reduviidae en ambientes domésticos y extradomésticos. Corrientes, Argentina Detection of triatomines (Hemiptera: Reduviidae in domiciliary and extra-domiciliary ecotopes. Corrientes, Argentina

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    Miryam Pieri Damborsky

    2001-08-01

    Full Text Available Esta investigación tiene como objetivo identificar los triatominos que predominan en ambientes domésticos y extradomésticos de diferentes departamentos de la Provincia de Corrientes mediante muestreos llevados a cabo desde 1985 hasta 1995. En los ecótopos domiciliarios se detectaron Triatoma infestans (Klug, 1834, Triatoma sordida (Stål, 1859, Panstrongylus geniculatus (Latreille, 1811 y Panstrongylus megistus (Burmeister, 1835. T. infestans y T. sordida se hallaron también en ambientes peridomésticos. Triatoma platensis (Neiva, 1913, Psammolestes coreodes (Bergroth, 1911, T. sordida y Triatoma rubrovaria (Blanchard, 1843 se colectaron en biótopos silvestres. En los domicilios, se confirmó el predominio de T. infestans. Esta especie fue la única parasitada por tripanosomas cruziformes. Si bien T. sordida fue más frecuente en los ecótopos extradomésticos, se demostró su tendencia a colonizar los ambientes domésticos.In order to identify intra- and extra-domiciliary triatomines, a study in different counties of Corrientes Province, Argentina, was conducted from 1985 to 1995. Triatoma infestans (Klug, 1834, Triatoma sordida (Stål, 1859, Panstrongylus geniculatus (Latreille, 1811, and Panstrongylus megistus (Burmeister, 1835 were detected in domestic ecotopes. T. infestans and T. sordida were also found in the peridomicile. Triatoma platensis (Neiva, 1913, Psammolestes coreodes (Bergroth, 1911, T. sordida, and Triatoma rubrovaria (Blanchard, 1843 were collected in sylvatic biotopes. T. infestans was confirmed as the predominant species in the domestic environment and was the only species infected with Trypanosoma cruzi-like parasites. T. sordida was most frequent in extra-domiciliary ecotopes, but could be considered capable of colonizing human dwellings.

  4. Avaliação de óleos essenciais de plantas aromáticas com atividade inseticida em Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae = Evaluation of essential oils with insecticidal activity in Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae

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    Suellem Petilim Gomes

    2011-07-01

    Full Text Available A doenca de Chagas e um dos maiores problemas de saude publica na America Latina. Neste trabalho, foi avaliada a acao inseticida de oleos essenciais de Anacardium humile Cymbopogon nardus, Ocimum basilicum e Eucalyptus urograndis em ninfas do 3‹ e 4‹ estadios dedesenvolvimento de Triatoma infestans por acao topica e pressao a vapor (fumigacao. Para o teste topico foram realizadas duas repeticoes cada uma com cinco ninfas de 3‹ e 4‹ estadios de desenvolvimento de T. infestans. Foi aplicado 1ƒÊL de cada concentracao na regiao dorsal de cada individuo. Para o teste de fumigacao foram utilizados potes de 2 L com tampa vedante. Os oleos essenciais de O. gratissimum e E. urograndis apresentaram atividadeinseticida para T. infestans, e A. humile e C. nardus apresentaram em media 5 e 15% de mortalidade, respectivamente. Para fumigacao, somente o oleo de E. urograndis teve efeito, com 100% de mortalidade sobre T. infestans , sendo que para os outros oleos nao foiobservado efeito de fumigacao. Esse trabalho relata pela primeira vez a acao inseticida de E. urograndis em potes fumigenos para o controle de triatomineos. Os resultados sao importantes devido a busca por novos modelos moleculares com acao inseticida em triatomineos resistentes aos inseticidas sinteticos.Chagas disease is a major public health problem in Latin America. This work aimed to evaluate the insecticide action of essential oils of Anacardium humile, Cymbopogon nardus, Ocimum basilicum and Eucalyptus urograndis on Triatoma infestans nymphs of third and fourth stages of development by topic action and steam pressure (fumigation. Two repetitions were performed at the topic test with five nymphs of third and fourth stages of development of T. infestans. It was applied 1ƒÊL of each concentration on the dorsal region of each nymph. Two-liter pots with sealing covers were used at the fumigation test. The essential oils of O. gratissimum and E. urograndis showed insecticidal activity against T. infestans and A. humile and C. nardus showed an average of 5 and 15% mortality, respectively. For the fumigation, only the E. urograndis oil had effect with 100% of mortality on T. infestans and for the other oils it was not observed any effect of the steam pressure. This paper describes for the first time the insecticidal action of E. urograndis in smoke canister to control bugs. The results are important to the search for new molecular models with insecticidal action in bugs which are resistant to synthetic insecticides.

  5. Avaliação de óleos essenciais de plantas aromáticas com atividade inseticida em Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae Evaluation of essential oils with insecticidal activity in Triatoma infestans (Klug, 1834 (Hemiptera: Reduviidae

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    Silvio Favero

    2011-09-01

    Full Text Available A doença de Chagas é um dos maiores problemas de saúde pública na América Latina. Neste trabalho, foi avaliada a ação inseticida de óleos essenciais de Anacardium humile Cymbopogon nardus, Ocimum basilicum e Eucalyptus urograndis em ninfas do 3° e 4° estádios de desenvolvimento de Triatoma infestans por ação tópica e pressão a vapor (fumigação. Para o teste tópico foram realizadas duas repetições cada uma com cinco ninfas de 3° e 4° estádios de desenvolvimento de T. infestans. Foi aplicado 1µL de cada concentração na região dorsal de cada indivíduo. Para o teste de fumigação foram utilizados potes de 2 L com tampa vedante. Os óleos essenciais de O. gratissimum e E. urograndis apresentaram atividade inseticida para T. infestans, e A. humile e C. nardus apresentaram em média 5 e 15% de mortalidade, respectivamente. Para fumigação, somente o óleo de E. urograndis teve efeito, com 100% de mortalidade sobre T. infestans, sendo que para os outros óleos não foi observado efeito de fumigação. Esse trabalho relata pela primeira vez a ação inseticida de E. urograndis em potes fumígenos para o controle de triatomíneos. Os resultados são importantes devido à busca por novos modelos moleculares com ação inseticida em triatomíneos resistentes aos inseticidas sintéticos.Chagas disease is a major public health problem in Latin America. This work aimed to evaluate the insecticide action of essential oils of Anacardium humile, Cymbopogon nardus, Ocimum basilicum and Eucalyptus urograndis on Triatoma infestans nymphs of third and fourth stages of development by topic action and steam pressure (fumigation. Two repetitions were performed at the topic test with five nymphs of third and fourth stages of development of T. infestans. It was applied 1µL of each concentration on the dorsal region of each nymph. Two-liter pots with sealing covers were used at the fumigation test. The essential oils of O. gratissimum and E. urograndis showed insecticidal activity against T. infestans and A. humile and C. nardus showed an average of 5 and 15% mortality, respectively. For the fumigation, only the E. urograndis oil had effect with 100% of mortality on T. infestans and for the other oils it was not observed any effect of the steam pressure. This paper describes for the first time the insecticidal action of E. urograndis in smoke canister to control bugs. The results are important to the search for new molecular models with insecticidal action in bugs which are resistant to synthetic insecticides.

  6. Observações sôbre o ciclo evolutivo do Triatoma arthurneivai, em condições de laboratório (Hemiptera, Reduviidae Studies on the evolution cycle of Triatoma arthurneivai under laboratory conditions (Hemiptera, Reduviidae

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    Edmundo Juarez

    1970-06-01

    Full Text Available A partir de ovos de fêmeas de Triatoma arthurneivai capturadas no ecótopo natural observou-se o tempo de evolução, em condições de laboratório mantidas à temperatura de 25°C e 60-70% de umidade relativa do ar. Foram oferecidos repastos sanguíneos em camundongo albino, semanalmente. A taxa de eclosão de ovos foi de 92,8%. Observaram-se diferenças entre o tempo de evolução desde a eclosão do ôvo até a muda para adulto, quando os triatomíneos foram criados isoladamente ou em grupos de 2-9 espécimes. O tempo médio dêstes foi de 228,3 dias e o daqueles, de 314,4 dias. O mesmo tempo, também apresentou diferenças quando se levou em consideração o sexo; os machos tiveram um tempo médio de 205,4 dias enquanto para as fêmeas o tempo foi de 274,3 dias. Algumas hipóteses são apresentadas, porém nenhuma ofereceu possibilidades de confirmação. Conclue-se pela necessidade de novos trabalhos para elucidar as dúvidas e, sugere-se possibilidade de novos conhecimentos a serem utilizados no estudo da tripanossomose americana em seus focos naturais.Data about Triatoma arthurneivai reared in laboratory from eggs laids by sylvatic females are reported. Laboratory conditions were maintaned at 25°C of temperature and 60-70% of relative humidity. Blood meal were furnished weekly from white mice sources. Eggs ecloded at a proportion of 92.8%. Differences were observed between triatomid reared in a individual or in a jointly manner. They were maintened in groups of 2-9 specimens each. The egg to adult times were 314.4 and 228.3 days for these two groups. Males reared more faster spent 205.4 days from egg to adult; females took 274.3 days. Some hypotesis were presented for explaining these differences, but no conclusions were reached. It was concluded that new investigations to explain the phenomena and help to understand better the dynamics of the South American trypanosomiasis in their natural foci should be performed.

  7. Patrones de alimentación y de defecación de Triatoma rubrovaria (Heteroptera: Reduviidae bajo condiciones de laboratorio Feeding and defecation patterns in Triatoma rubrovaria (Heteroptera: Reduviidae under laboratory conditions

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    María E. Bar

    2003-07-01

    Full Text Available La capacidad de Triatoma rubrovaria Blanchard para colonizar la vivienda y alimentarse de sangre humana y sus índices de infección por Trypanosoma cruzi Chagas, justifican esta investigación. El objetivo fue caracterizar los patrones de alimentación y defecación en condiciones experimentales. Ambos patrones se evaluaron simultáneamente. Se utilizaron 30 ninfas de cuarto estadio, 30 de quinto y 30 adultos. Los ejemplares se alimentaron sobre ave (gallina durante una hora. Se pesaron antes y después de la ingesta, calculándose por diferencia la cantidad de sangre ingerida. Se midió el tiempo en que ocurrió la primera defecación y siguientes. Se realizaron tres repeticiones para cada estadio ninfal y para el estado adulto. Se confirmó alimentación en 97,0% de los individuos, alimentándose a repleción el 84,7%. El ataque se inició en un tiempo promedio de 2 minutos. El 28,6% interrumpió la alimentación para defecar o por irritabilidad del huésped. En promedio las N5 consumieron más sangre que las N4 (358,1 y 120,9 mg respectivamente y que los adultos (73,5 mg. Del total de individuos alimentados se verificó defecación en 92,4%. El tiempo promedio de la primera deyección fue de 1,7 minutos. Se concluye que T. rubrovaria mostró rapidez en la obtención del alimento y en la emisión de la primera defecación. Se discute su potencial como vector de T. cruzi.Triatoma rubrovaria Blanchard capability to colonize the domicile, to feed upon human and its Trypanosoma cruzi Chagas infection rates justify this investigation. The aim was to characterize the feeding and defecation patterns of T. rubrovaria under laboratory conditions. Both patterns were evaluated simultaneously using 30 fourth-instar and 30 fifth-instar nymphs, and 30 adults. Three repetitions for each nymphal stadium and for the adult stage were made. The insects were fed on chicken during one hour and were weighed before and after feeding, and the blood meal size was determined. The time of the first and subsequent defaecations were measured. It was confirmed blood ingestion in 97.0% of the triatomines and 84.7% fed to repletion. On average the attack time started after 2 minutes. Feeding interruption was observed in 28.6% and was due principally to defecate or as a consequence of host irritability. The mean amount of blood obtained by the fifth-instar nymphs was greater than the blood ingested by the fourth-instar (358.1 and 120.9 mg, respectively and the adults (73.5 mg. Defecation was verified in the 92.4% of the feeding individuals. The first dejection was emitted on average at 1.7 minutes. It is concluded that T. rubrovaria was fast to obtain its bloodmeal and to emitt the first dejection. Its potential as T. cruzi vector is discussed.

  8. Sobrevivência e ocorrência de muda em Triatoma infestans Klug (Hemiptera, Reduviidae após choque de temperatura Survival and molting occurrence in Triatoma infestans Klug (Hemiptera, Reduviidae after temperature shocks

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    Vera Lúcia C.C. Rodrigues

    1991-12-01

    Full Text Available A sobrevivência e a ocorrência de mudas em espécimes de Triatoma infestans foram estudados num período de 30 dias após choques de temperatura. Foi demonstrado que choques hipertérmico e hipotérmico interferem nesses processos, na dependência da temperatura do choque, tempo de sua duração, fase de desenvolvimento e sexo dos espécimes. Dentre as situações experimentais utilizadas, o choque a 0°C por 12 h pareceu produzir a ação mais deletéria, porém choques a 40°C e 0°C mesmo por uma hora são admitidos como afetando o desenvolvimento hormonal que controla a muda. Casos de aumento de sobrevivência pós-choque são sugeridos como tendo sido favorecidos por ação de proteínas de choque térmico.Survival and molting occurrence were studied in specimens of Triatoma infestans over 30 days after temperature shocks. Hyperthermal and hypotermal shocks could be found to affect both survival and molting incidence as a function of temperature and period of the developement phase and sex of the specimens. Considering the various test conditions, the shock at 0°C for 12 h was found to elicit the most deleterious effect, whereas shocks at 40°C and 0°C even for 1 h are interpreted as affecting the hormonal balance which controls molting. Cases of a rise in post-shock survival are suggested to have been favored by heat-shock protein action.

  9. Toxicity of pyrethroids and repellency of diethyltoluamide in two deltamethrin-resistant colonies of Triatoma infestans Klug, 1834 (Hemiptera: Reduviidae

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    Valeria Sfara

    2006-02-01

    Full Text Available The aim of the currrent investigation was to evaluate (a the toxicity of three pyrethroids (deltamethrin, lambda-cyhalothrin, and tetramethrin; (b the effect of these insecticides on the locomotor activity; and (c the repellent effect of N,N-diethyl-m-toluamide (DEET on two deltamethrin-resistant strains of Triatoma infestans from Argentina (El Chorro and La Toma, and one susceptible strain. The resistance ratios (RRs obtained for the La Toma strain were: > 10,769, 50.7, and > 5.2 for deltamethrin, lambda-cyhalothrin, and tetramethrin respectively. The RRs for the El Chorro strain were: > 10,769, 85.8, and > 5.2 for deltamethrin, lambda-cyhalothrin, and tetramethrin respectively. The hyperactivity usually caused by the three pyrethroids was in both the deltamethrin-resistant strains compared to the susceptible reference strain. No differences were observed in the repellent effect of DEET between the three groups. These results indicate that the deltamethrin-resistant insects have a cross resistance to lambda-cyhalothrin and tetramethrin, and are also resistant to the first symptom of pyrethroid poisoning (hyperactivity. However, the sensorial process related to DEET repellency does not appear to be altered.

  10. Examining Mechanisms of Pyrethroid Resistance in Eggs of Two Populations of the Chagas' Disease Vector Triatoma infestans (Hemiptera: Reduviidae).

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    Roca-Acevedo, G; Picollo, M I; Capriotti, N; Sierra, I; Santo-Orihuela, P L

    2015-09-01

    Chagas disease is a zoonosis transmitted to man by blood-sucking triatomine bugs found in the Americas. Triatoma infestans (Klug, 1834) is the main vector of Chagas' disease in Argentina. The control of this illness relies heavily on vector control through the use of insecticide. However, resistance to pyrethroid insecticides associated with ineffective field treatments has been increasingly reported in T. infestans from Argentina and Bolivia. There are few reports on the expression and causes of resistance in eggs of resistant populations, and even fewer studies on insecticide resistance throughout embryonic development. In this study, we explore the biochemical and molecular mechanisms potentially associated with the deltamethrin resistance assessed in the developing eggs of the Argentinean (Campo Largo) and Bolivian (Entre Ríos) T. infestans populations.We found measurable activity of monooxigenases and pyrethroid esterases throughout embryonic development. The pyrethroid esterase activity grew steadily throughout development in all the studied populations and was highest in eggs 12 d old. Mean enzyme activity increased from 13.6 to 16.3 and 22.2 picomol 7-hydroxycoumarin/min (7-OHC) in eggs of 4-, 7-, and 12 d old from the susceptible reference bug colony. Mean activity of resistant populations increased from 16.0 to 25.9 picomol 7-OHC/min in eggs of 4- to 12 d old in Entre Ríos population, and from 15.9 to 28.9 picomol 7-OHC/min in Campo Largo population. Molecular analysis of susceptible and resistant developing eggs detected L1014F mutation in both resistant populations, but no L925I mutation was found in any of the studied populations.Higher esterase activity and L1014F presence justify the resistance to pyrethroid throughout developing eggs of both studied T. infestans populations. The description of resistance profiles including resistance mechanisms involved will allow a rational design of campaigns for the control of Chagas disease transmission. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Factors associated with the occurrence of Triatoma sordida (Hemiptera: Reduviidae in rural localities of Central-West Brazil

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    Juliana Chedid Nogared Rossi

    2015-04-01

    Full Text Available This study estimates the factors of artificial environments (houses and peridomestic areas associated with Triatoma sordida occurrence. Manual searches for triatomines were performed in 136 domiciliary units (DUs in two rural localities of Central-West Brazil. For each DU, 32 structural, 23 biotic and 28 management variables were obtained. Multiple logistic regression analysis was performed in order to identify statistically significant variables associated with occurrence of T. sordida in the study areas. A total of 1,057 specimens (99% in peridomiciles, mainly chicken coops of T. sordida were collected from 63 DUs (infestation: 47%; density: ~8 specimens/DU; crowding: ~17 specimens/infested DU; colonisation: 81%. Only six (0.6% out of 945 specimens examined were infected with Trypanosoma cruzi. The final adjusted logistic regression model indicated that the probability of T. sordida occurrence was higher in DU with wooden chicken coops, presence of > 30 animals in wooden corrals, presence of wood piles and presence of food storeroom. The results show the persistence of T. sordida in peridomestic habitats in rural localities of Central-West Brazil. However, the observed low intradomestic colonisation and minimal triatomine infection rates indicate that T. sordida has low potential to sustain high rates of T. cruzi transmission to residents of these localities.

  12. Selective Insecticide Applications Directed Against Triatoma infestans (Hemiptera: Reduviidae) Affected a Nontarget Secondary Vector of Chagas Disease, Triatoma garciabesi.

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    Rodríguez-Planes, L I; Vazquez-Prokopec, G M; Cecere, M C; Canale, D M; Gürtler, R E

    2016-01-01

    The control of nondomiciliated triatomine species adapted to peridomestic habitats represents a challenge because they are connected to sylvatic colonies, and pyrethroid insecticides have limited effects outdoors. The effects of residual insecticide spraying have rarely been assessed on secondary triatomines. Triatoma garciabesi (Carcavallo, Martinez, Cichero, Prosen & Ronderos, 1967) is a nontarget vector that inhabits the dry western Chaco region, and a member of the Triatoma sordida Stål 1859 complex. Little is known on the capacity of T. garciabesi to invade and establish viable domestic or peridomestic colonies, and on its response to residual insecticide sprays directed against Triatoma infestans Klug 1834. The presence and abundance of triatomines were assessed by timed manual collections annually or biannually (spring and fall) during 10 yr after a community-wide insecticide spraying campaign and selective insecticide sprays directed against T. infestans in a rural village of northwestern Argentina. T. garciabesi mainly occupied peridomestic habitats associated with chickens, and was unable to colonize human sleeping quarters. Trees with chickens occurred in nearly all houses and were infested in >25% of the occasions. The abundance of bugs at house-compound level was best explained by a generalized estimating equation model that included selective insecticide sprays during the previous semester (negative effects), chicken abundance (positive effects), seasonality, and their interactions. Our results suggest that insecticide applications targeting T. infestans affected the abundance of T. garciabesi, and reduced the likelihood of future infestation. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Factors associated with the occurrence of Triatoma sordida (Hemiptera: Reduviidae) in rural localities of Central-West Brazil

    Science.gov (United States)

    Rossi, Juliana Chedid Nogared; Duarte, Elisabeth C; Gurgel-Gonçalves, Rodrigo

    2015-01-01

    This study estimates the factors of artificial environments (houses and peridomestic areas) associated with Triatoma sordida occurrence. Manual searches for triatomines were performed in 136 domiciliary units (DUs) in two rural localities of Central-West Brazil. For each DU, 32 structural, 23 biotic and 28 management variables were obtained. Multiple logistic regression analysis was performed in order to identify statistically significant variables associated with occurrence of T. sordida in the study areas. A total of 1,057 specimens (99% in peridomiciles, mainly chicken coops) of T. sordida were collected from 63 DUs (infestation: 47%; density: ~8 specimens/DU; crowding: ~17 specimens/infested DU; colonisation: 81%). Only six (0.6%) out of 945 specimens examined were infected with Trypanosoma cruzi. The final adjusted logistic regression model indicated that the probability of T. sordida occurrence was higher in DU with wooden chicken coops, presence of > 30 animals in wooden corrals, presence of wood piles and presence of food storeroom. The results show the persistence of T. sordida in peridomestic habitats in rural localities of Central-West Brazil. However, the observed low intradomestic colonisation and minimal triatomine infection rates indicate that T. sordida has low potential to sustain high rates of T. cruzi transmission to residents of these localities. PMID:25946242

  14. Comparative egg morphology of six Meccus species and Triatoma recurva (Stål, 1868) Hemiptera: Reduviidae.

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    Rivas, Nancy; Sánchez-Espíndola, Esther; Camacho, Alejandro D; Alejandre-Aguilar, Ricardo

    2016-06-01

    We investigated the morphology and morphometry of eggs from the colonies of the Entomology Laboratory at ENCB-IPN belonging to six species of the genus Meccus and Triatoma recurva, using both light and scanning electron microscopy. Egg ornamentation is an important parameter to consider in the differentiation of species. Samples were observed under a scanning electron microscope. Measurements of fifty eggs per species included length, width, and opercular diameter, which were used for the morphometric analysis. The results showed that the seven species display a polygonal ornamentation dominated by hexagons; the operculum shows also a polygonal ornamental characteristic in each species. Morphometry provided valuable information for discriminating between closely related species of the genus Meccus and Triatoma recurva, a species akin to this group, thereby facilitating the complete discrimination of these species. © 2016 The Society for Vector Ecology.

  15. Revalidation of Triatoma bahiensis Sherlock & Serafim, 1967 (Hemiptera: Reduviidae) and phylogeny of the T. brasiliensis species complex.

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    Mendonça, Vagner José; Alevi, Kaio Cesar Chaboli; Pinotti, Heloisa; Gurgel-Gonçalves, Rodrigo; Pita, Sebastián; Guerra, Ana Letícia; Panzera, Francisco; De Araújo, Renato Freitas; Azeredo-Oliveir, Maria Tercília Vilela De; Rosa, João Aristeu Da

    2016-05-02

    Triatoma bahiensis Sherlock & Serafim, 1967, T. lenti Sherlock & Serafim, 1967, and T. pessoai Sherlock & Serafim, 1967 were described based on material collected in the Brazilian state of Bahia. These species were later included in the T. brasiliensis complex based on their geographic distribution. Triatoma bahiensis and T. pessoai were subsequently synonymized with T. lenti. However, the phylogenetic position of T. lenti within the T. brasiliensis complex has remained doubtful. This study aims to assess the taxonomic status of T. bahiensis and to infer the phylogenetic relationships between T. lenti, T. bahiensis and the other members of the T. brasiliensis species complex. The identities of the species in concern were confirmed by comparisons with high resolution photos of the respective type materials; lectotypes are designated for T. pessoai and T. bahiensis. Morphological, morphometric, molecular, and cytogenetic approaches as well as experimental crosses were used. The low viability of experimental crosses combined with morphological and morphometric data allow the differentiation of T. bahiensis and T. lenti. Pairwise cyt b sequence divergence between T. lenti and T. bahiensis was 2.5%. Cytogenetic and molecular analyses grouped T. lenti and T. bahiensis as members of the T. brasiliensis complex. These results revalidate the specific status of T. bahiensis.

  16. Estadísticos poblacionales de Triatoma sordida Stäl 1859 (Hemiptera : Reduviidae en condiciones experimentales

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    Oscherov Elena B.

    1996-01-01

    Full Text Available Se realizó el seguimiento longitudinal de cuatro cohortes de 100 huevos cada una. Los insectos fueron criados a 28°C ± 3°C y 63 % ± 10% de humedad relativa, y alimentados cada siete días sobre gallina (Gallus domesticus, durante 40 min. Las cohortes fueron controladas una vez por semana. Se observó un valor constante de supervivencia en las cuatro cohortes, sin picos importantes. La expectativa de vida de los machos, en promedio, fue de 37,4 semanas y la de las hembras 36,8. El tiempo generacional demandó 61,7 semanas. La tasa reproductiva neta indica que esta población se incrementará 143,3 veces con cada generación. La tasa intrínseca de crecimiento natural fue de 0,082 por semana. El máximo valor reproductivo se verificó, en promedio, a la tercer semana del ingreso al estado adulto. La distribución estable de edades de T. sordida sería de 32% huevos, 26% ninfas de primer estadio, 19% ninfas de segundo estadio, 13% ninfas de tercer estadio, 6% ninfas de cuarto estadio, 3% ninfas de quinto estadio y 1% de adultos. Es la primera cita para Argentina sobre la tabla de vida de T. sordida. El análisis de estos parámetros permite considerar que esta especie se comporta como "K estratega", en condiciones experimentales.

  17. Evaluación del efecto insecticida de tierra de diatomeas sobre Triatoma infestans (Hemíptera, Reduviidae

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    Mariana L Bilbao

    2007-04-01

    Full Text Available El Triatoma infestans es el principal vector de la enfermedad de Chagas en Argentina. La tierra de diatomeas (TD es un producto natural que se comercializa actualmente con fines insecticidas y que produce la muerte por deshidratación. Se evaluó la eficacia insecticida de TD al 60% de pureza, proveniente del yacimiento La Iglesiana (San Juan, Argentina sobre ninfas V y adultos de T.infestans. Se ensayaron dos dosis: 112,5 g/m2 (T1 y 225 g/m2 (T2, con cuatro réplicas por tratamiento, con cinco ejemplares, incluyendo los controles (TC en el laboratorio. Se contaron los individuos vivos y muertos durante cinco días. No se encontró diferencias en la mortalidad (ANOVA, p>0,05 en los adultos (T1: 40%, T2: 25% y TC: 30% ni en las ninfas V (T1: 10%, T2: 15% y TC: 10%. Se concluye que la tierra de diatomeas del yacimiento La Iglesiana, en las condiciones de laboratorio evaluadas, no posee capacidad insecticida sobre T.infestans.

  18. Reproductive isolation revealed in preliminary crossbreeding experiments using field collected Triatoma dimidiata (Hemiptera: Reduviidae) from three ITS-2 defined groups.

    Science.gov (United States)

    García, Mauricio; Menes, Marianela; Dorn, Patricia L; Monroy, Carlota; Richards, Bethany; Panzera, Francisco; Bustamante, Dulce María

    2013-12-01

    Triatoma dimidiata, a Chagas disease vector distributed in Mexico, Central America, Colombia, Venezuela, Peru and Ecuador, has been studied using genetic markers and four groups have been defined by ITS-2 sequences: 1A, 1B, 2 and 3. To gather evidence on the divergence and reproductive isolation among T. dimidiata ITS-2 groups, we carried out 15 crossbreeding experiments with field-collected sylvan and domestic T. dimidiata from Guatemala where three groups are found: 1A, 2 and 3. Reciprocal crosses between individuals from groups 1A and 2, and a cross between group 2 individuals from different habitats, produced an average 129.78±42.29 eggs with hatching success ranging from 31.6 to 90.1%. The offspring of these crosses reached the adult stage, and crosses between F1 insects produced eggs. These results suggest that there are no pre- or post-zygotic reproductive barriers between groups 1A and 2, or within group 2. Crosses between group 3 females and males from groups 1A or 2 produced on average 85.67±30.26 eggs and none of them hatched. These results support the existence of pre-zygotic barriers between T. dimidiata group 3 and groups 1A and 2. The group 3 individuals were collected in sylvatic environments in Yaxha, Peten, Guatemala. Previously, distinct chromosomal characteristics (cytotype 3) were described in individuals from this population. Based on this evidence we suggest that this population is divergent at the species level from other T. dimidiata populations. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Reproductive isolation revealed in preliminary crossbreeding experiments using field collected Triatoma dimidiata (Hemiptera: Reduviidae) from three ITS–2 defined groups

    Science.gov (United States)

    García, Mauricio; Menes, Marianela; Dorn, Patricia L.; Monroy, Carlota; Richards, Bethany; Panzera, Francisco; Bustamante, Dulce María

    2013-01-01

    Triatoma dimidiata, a Chagas disease vector distributed in Mexico, Central America, Colombia, Venezuela, Peru and Ecuador, has been studied using genetic markers and four groups have been defined by ITS–2 sequences: 1A, 1B, 2 and 3. To gather evidence on the divergence and reproductive isolation among T. dimidiata ITS–2 groups, we carried out 15 crossbreeding experiments with field–collected sylvan and domestic T. dimidiata from Guatemala where three groups are found: 1A, 2 and 3. Reciprocal crosses between individuals from groups 1A and 2, and a cross between group 2 individuals from different habitats, produced an average 129.78±42.29 eggs with hatching success ranging from 31.6% to 90.1%. The offspring of these crosses reached the adult stage, and crosses between F1 insects produced eggs. These results suggest that there are no pre– or post– zygotic reproductive barriers between groups 1A and 2, or within group 2. Crosses between group 3 females and males from groups 1A or 2 produced on average 85.67±30.26 eggs and none of them hatched. These results support the existence of pre– zygotic barriers between T. dimidiata group 3 and groups 1A and 2. The group 3 individuals were collected in sylvatic environments in Yaxha, Peten, Guatemala. Previously, distinct chromosomal characteristics (cytotype 3) were described in individuals from this population. Based on this evidence we suggest that this population is divergent at the species level from other T. dimidiata populations. PMID:24041592

  20. Reproductive isolation revealed in preliminary crossbreeding experiments using field collected Triatoma dimidiata (Hemiptera: Reduviidae) from three ITS–2 defined groups

    OpenAIRE

    García, Mauricio; Menes, Marianela; Dorn, Patricia L.; Monroy, Carlota; Richards, Bethany; Panzera, Francisco; Bustamante, Dulce María

    2013-01-01

    Triatoma dimidiata, a Chagas disease vector distributed in Mexico, Central America, Colombia, Venezuela, Peru and Ecuador, has been studied using genetic markers and four groups have been defined by ITS–2 sequences: 1A, 1B, 2 and 3. To gather evidence on the divergence and reproductive isolation among T. dimidiata ITS–2 groups, we carried out 15 crossbreeding experiments with field–collected sylvan and domestic T. dimidiata from Guatemala where three groups are found: 1A, 2 and 3. Reciprocal ...

  1. New structures for goat corrals to control peridomestic populations of Triatoma infestans (Hemiptera: Reduviidae in the Gran Chaco of Argentina

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    David Eladio Gorla

    2013-05-01

    Full Text Available Goat production is an important economic activity for rural communities in the Gran Chaco of Argentina. Goat corrals are important for the survival of peridomestic populations of Triatoma infestans. This study evaluated the impact of modifying the traditional structure of goat corrals on T. infestans populations and goat productivity in the region of Los Llanos (La Rioja. Thirty-nine experimental corrals were constructed and 57 traditional corrals were used as controls. We evaluated the infestations of the control and experimental corrals for five years following construction of the structures. The results showed that the new structures did not prevent the colonization, although it enhanced the detection of infestation at low densities of T. infestans. No significant difference was found in T. infestans population abundance between control and experimental corrals, probably because of the different detectability in the two types of structures, especially among the small nymphs. Although goat productivity average was higher in experimental than in control corrals, no significant difference was found because of high variability. The new structures can be used as a complement to promote the development of rural communities. Acceptability and adoption of the new corrals by the owners was high, as the enclosures offered better protection for the goats, increased growth of kids and facilitated herd handling.

  2. Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae in State of Ceará, Northeastern Brazil

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    Grasielle Caldas D'Ávila Pessoa

    2015-02-01

    Full Text Available INTRODUCTION: Triatoma brasiliensis is the species of greatest epidemiological relevance in the semi-arid region of Brazil. This species is predominantly found in domestic environments, and it has the ability to build large colonies with high levels of natural infection via Trypanosoma cruzi. Thus, T. brasiliensis is one of the most efficient transmitters of Chagas disease (CD to humans. Despite household spraying with residual insecticides, many areas report persistent reinfestations for reasons that remain poorly understood. Therefore, this study sought to characterize the toxicological profile of deltamethrin in T. brasiliensis from areas with persistent reinfestation in State of Ceará, Brazil. METHODS: The susceptibility reference lineage (SRL was derived from Umari. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 (0.851 nanograms of active ingredient per treated nymph of the SRL. RESULTS: The susceptibility profile characterization of the T. brasiliensis populations revealed 50% resistance ratios (RR50 that ranged from 0.32 to 1.21. The percentage of mortality in response to the diagnostic dose was 100%. CONCLUSIONS: We demonstrated that T. brasiliensis was highly susceptible to deltamethrin. The control difficulties found might be related to the recolonization of the triatomines originating from neighboring environments and the possible operational failures related to the process of spraying that enabled specimens less susceptible to deltamethrin to survive.

  3. Comportamiento de Rhodnius robustus Larousse, 1927 (Hemiptera, Reduviidae durante su alimentación en condiciones de laboratorio

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    Camilo Rubio

    2013-06-01

    Full Text Available Introducción. A pesar del control de los insectos domiciliados, se siguen presentando casos de enfermedad de Chagas con la participación en la transmisión de especies peridomiciliarias y selváticas,una de las cuales es Rhodnius robustus, especie reportada con infecciones naturales de Trypanosoma cruzi y T. rangeli. Objetivo. Describir el comportamiento de R. robustus durante su alimentación en condiciones delaboratorio.Materiales y métodos. En cada estadio de desarrollo de R. robustus se analizó el tiempo promedio para alcanzar la repleción, número promedio de deyecciones, porcentaje de individuos que defecan durante la comida y ganancia de peso después de la alimentación. Resultados. Rhodnius robustus tardó entre 19:26 y 44:55 (minutos:segundos en alimentarse arepleción; los insectos defecaron en todos sus diferentes estadios durante la alimentación. El porcentaje de individuos que defecan durante la alimentación varía de 13,3 % a 93,3 %. Por otro lado, el consumo promedio de sangre en el quinto estadio, 337,19 mg, duplica la cantidad ingerida por los adultos, 161,25 mg. Conclusiones. En todos los estadios de R. robustus hay defecación durante la alimentación, factor que favorece su competencia vectorial. Sin embargo, el tiempo para la primera deyección, el porcentaje dedeyecciones y los individuos que defecan durante la comida, así como la cantidad de sangre ingerida, varían entre los estadios, lo cual indica que el comportamiento alimenticio está mediado por variables dependientes de la edad/estadio.   http://dx.doi.org/10.7705/biomedica.v33i2.743

  4. Migration and Gene Flow Among Domestic Populations of the Chagas Insect Vector Triatoma dimidiata (Hemiptera: Reduviidae) Detected by Microsatellite Loci

    Science.gov (United States)

    Stevens, Lori; Monroy, M. Carlota; Rodas, Antonieta Guadalupe; Hicks, Robin M.; Lucero, David E.; Lyons, Leslie A.; Dorn, Patricia L.

    2015-01-01

    Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the parasite Trypanosoma cruzi in Central America, and particularly in Guatemala. Tr. cruzi is the causative agent of Chagas disease, and successful disease control requires understanding the geographic distribution and degree of migration of vectors such as T. dimidiata that frequently re-infest houses within months following insecticide application. The population genetic structure of T. dimidiata collected from six villages in southern Guatemala was studied to gain insight into the migration patterns of the insects in this region where populations are largely domestic. This study provided insight into the likelihood of eliminating T. dimidiata by pesticide application as has been observed in some areas for other domestic triatomines such as Triatoma infestans. Genotypes of microsatellite loci for 178 insects from six villages were found to represent five genetic clusters using a Bayesian Markov Chain Monte Carlo method. Individual clusters were found in multiple villages, with multiple clusters in the same house. Although migration occurred, there was statistically significant genetic differentiation among villages (FRT = 0.05) and high genetic differentiation among houses within villages (FSR = 0.11). Relatedness of insects within houses varied from 0 to 0.25, i.e., from unrelated to half-sibs. The results suggest that T. dimidiata in southern Guatemala moves between houses and villages often enough that recolonization is likely, implying the use of insecticides alone is not sufficient for effective control of Chagas disease in this region and more sustainable solutions are required. PMID:26334816

  5. Biogeography and evolution of Amazonian triatomines (Heteroptera: Reduviidae: implications for Chagas disease surveillance in humid forest ecoregions

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    Fernando Abad-Franch

    2007-10-01

    Full Text Available An ecological-evolutionary classification of Amazonian triatomines is proposed based on a revision of their main contemporary biogeographical patterns. Truly Amazonian triatomines include the Rhodniini, the Cavernicolini, and perhaps Eratyrus and some Bolboderini. The tribe Rhodniini comprises two major lineages (pictipes and robustus. The former gave rise to trans-Andean (pallescens and Amazonian (pictipes species groups, while the latter diversified within Amazonia (robustus group and radiated to neighbouring ecoregions (Orinoco, Cerrado-Caatinga-Chaco, and Atlantic Forest. Three widely distributed Panstrongylus species probably occupied Amazonia secondarily, while a few Triatoma species include Amazonian populations that occur only in the fringes of the region. T. maculata probably represents a vicariant subset isolated from its parental lineage in the Caatinga-Cerrado system when moist forests closed a dry trans-Amazonian corridor. These diverse Amazonian triatomines display different degrees of synanthropism, defining a behavioural gradient from household invasion by adult triatomines to the stable colonisation of artificial structures. Anthropogenic ecological disturbance (driven by deforestation is probably crucial in the onset of the process, but the fact that only a small fraction of species effectively colonises artificial environments suggests a role for evolution at the end of the gradient. Domestic infestation foci are restricted to drier subregions within Amazonia; thus, populations adapted to extremely humid rainforest microclimates may have limited chances of successfully colonising the slightly drier artificial microenvironments. These observations suggest several research avenues, from the use of climate data to map risk areas to the assessment of the synanthropic potential of individual vector species.

  6. Influence of blood meal and mating in reproduction patterns of Triatoma brasiliensis females (Hemiptera: Reduviidae under laboratory conditions

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    Natália Faria Daflon-Teixeira

    2009-11-01

    Full Text Available The influence of blood meal and mating on Triatoma brasiliensis (Neiva female fecundity, fertility, life-span and the preoviposition period were investigated under laboratory conditions. Nourishment increased fecundity, fertility and adult lifespan, whereas mating increased fecundity, fertility and decreased the preoviposition period. Females also required more than one mating to reach their full reproductive potential. Results indicate that both nourishment and mating are important in T. brasiliensis proliferation. Such information will help towards developing effective control strategies of this vector of Chagas disease.

  7. Irradiation effects on the duration of intermolt in nymphs of the fourth instar of Panstrongylus megistus Burmeister, 1835 (Hemiptera: Reduviidae)

    International Nuclear Information System (INIS)

    Barros Falcao, P.H. de.

    1987-01-01

    The duration of intermolt, in nymphs of the fourth instar, of P. megistus, submitted to irradiation with Cobalt 60, 24 hs after the blood meal is studied. The insects were divided in four groups of 40 and were irradiated with doses of 10, 20, 40 and 80 Gray, respectively. (M.A.C.) [pt

  8. Comparison of insecticidal paint and deltamethrin against Triatoma infestans (Hemiptera: Reduviidae) feeding and mortality in simulated natural conditions.

    Science.gov (United States)

    Maloney, Kathleen M; Ancca-Juarez, Jenny; Salazar, Renzo; Borrini-Mayori, Katty; Niemierko, Malwina; Yukich, Joshua O; Naquira, Cesar; Keating, Joseph A; Levy, Michael Z

    2013-06-01

    The vector of Chagas disease, Triatoma infestans, is largely controlled by the household application of pyrethroid insecticides. Because effective, large-scale insecticide application is costly and necessitates numerous trained personnel, alternative control techniques are badly needed. We compared the residual effect of organophosphate-based insecticidal paint (Inesfly 5A IGR™ (I5A)) to standard deltamethrin, and a negative control, against T. infestans in a simulated natural environment. We evaluated mortality, knockdown, and ability to take a blood meal among 5(th) instar nymphs. I5A paint caused significantly greater mortality at time points up to nine months compared to deltamethrin (Fisher's Exact Test, p paint (Fisher's Exact Tests, p paint may provide an easily-applied means of protection against vectors of Chagas disease. © 2013 The Society for Vector Ecology.

  9. First record of Megaselia scalaris (Loew) (Diptera: Phoridae) infesting laboratory colonies of Triatoma brasiliensis Neiva (Hemiptera: Reduviidae)

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Jane; Almeida, Carlos E.; Esperanca, Gleidson M.; Morales, Ninive [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Dept.de Entomologia. Lab. da Colecao Entomologica; Mallet, Jacenir R. dos S.; Goncalves, Teresa C.M. [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Lab. Transmissores de Leishmanioses. Nucleo de Ultraestrutura; Prado, Angelo P. do [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Biologia. Dept. de Parasitologia

    2007-11-15

    Megaselia scalaris (Loew) is a cosmopolitan and synanthropic scuttle fly, eclectic in its feeding habits and acts as detritivore, parasite, facultative parasite, and parasitoid. Here we report for the first time M. scalaris infesting laboratory colonies of Triatoma brasiliensis Neiva, the most important Chagas disease vector in semiarid areas of Brazil. M. scalaris larvae were found feeding inside bugs; pupae were found in the esophagus and intestinal regions of T. brasiliensis through dissection. Other relevant information about this finding is also described in this note, including some preventive measures to avoid laboratory colonies infestations. (author)

  10. Pioneer study of population genetics of Rhodnius ecuadoriensis (Hemiptera: Reduviidae) from the central coastand southern Andean regions of Ecuador.

    Science.gov (United States)

    Villacís, Anita G; Marcet, Paula L; Yumiseva, César A; Dotson, Ellen M; Tibayrenc, Michel; Brenière, Simone Frédérique; Grijalva, Mario J

    2017-09-01

    Effective control of Chagas disease vector populations requires a good understanding of the epidemiological components, including a reliable analysis of the genetic structure of vector populations. Rhodnius ecuadoriensis is the most widespread vector of Chagas disease in Ecuador, occupying domestic, peridomestic and sylvatic habitats. It is widely distributed in the central coast and southern highlands regions of Ecuador, two very different regions in terms of bio-geographical characteristics. To evaluate the genetic relationship among R. ecuadoriensis populations in these two regions, we analyzed genetic variability at two microsatellite loci for 326 specimens (n=122 in Manabí and n=204 in Loja) and the mitochondrial cytochrome b gene (Cyt b) sequences for 174 individuals collected in the two provinces (n=73 and=101 in Manabí and Loja respectively). The individual samples were grouped in populations according to their community of origin. A few populations presented positive F IS, possible due to Wahlund effect. Significant pairwise differentiation was detected between populations within each province for both genetic markers, and the isolation by distance model was significant for these populations. Microsatellite markers showed significant genetic differentiation between the populations of the two provinces. The partial sequences of the Cyt b gene (578bp) identified a total of 34 haplotypes among 174 specimens sequenced, which translated into high haplotype diversity (Hd=0.929). The haplotype distribution differed among provinces (significant Fisher's exact test). Overall, the genetic differentiation of R. ecuadoriensis between provinces detected in this study is consistent with the biological and phenotypic differences previously observed between Manabí and Loja populations. The current phylogenetic analysis evidenced the monophyly of the populations of R. ecuadoriensis within the R. pallescens species complex; R. pallescens and R. colombiensis were more closely related than they were to R. ecuadoriensis. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Environmental management for the control of Triatoma dimidiata (Latreille, 1811, (Hemiptera: Reduviidae in Costa Rica: a pilot project

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    Rodrigo Zeledón

    2006-06-01

    Full Text Available An ecological control method, using environmental management operations, based on biological and behavioral characteristics of Triatoma dimidiata (Latreille, 1811, was implemented as a pilot project in an area of Costa Rica where the bug is prevalent. The sample was represented by 20 houses with peridomestic colonies (two also had indoor infestation, divided in two equivalent groups of 10 each. In one group we intervened the houses, i.e. all objects or materials that were serving as artificial ecotopes for the bugs were removed, and the second group was used as control houses. After a year of periodic follow up, it became evident that in those houses with a modified environment the number of insects had decreased notoriously even after the first visits and this was more evident after a period of 12.5 to 13.5 months in which no insects were detected in eight of the houses. It also became clear that in this group of houses, recolonization by wild bugs from the surrounding areas, became more difficult, probably due to the absence of protection from bug predators. In the control houses, with the exception of three in which the inhabitants decided to intervene on their own, and another house with a peculiar situation, the insect populations remained the same or even showed a tendency to increase, as confirmed at the end of the experiment. We believe that the method is feasible, low costing and non contaminating. It could be used successfully in other places where T. dimidiata is common and also in countries where other species colonize peridomestic areas of homes. Environmental management of this kind should seek the participation of the members of the communities, in order to make it a more permanent control measure.

  12. Life cycle of Triatoma ryckmani (Hemiptera: Reduviidae in the laboratory, feeding patterns in nature and experimental infection with Trypanosoma cruzi

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    Rodrigo Zeledón

    2010-02-01

    Full Text Available A cohort initiated with 121 eggs, yielding 105 first instar nymphs (eclosion rate: 86.78%, allowed us to observe the entire life cycle of Triatoma ryckmani under laboratory conditions (24ºC and 62% relative humidity, by feeding them on anesthetized hamsters. It was possible to obtain 62 adults and the cycle from egg to adult took a mean of 359.69 days with a range of 176-529 days (mortality rate of nymphs: 40.95%. Mean life span of adults was of 81 days for females and 148 days for males. The developmental periods of 4th and 5th nymphs were longer than those of the other instars. This suggests that young siblings have a better chance of taking a hemolymph meal from older ones, in order to survive during fasting periods during prolonged absences of vertebrate hosts from natural ecotopes. The stomach contents of 37 insects showed blood from rodents (15 cases, lizards (7 cases, birds (6 cases and insect hemolymph (7 cases. Out of 10 insects fed by xenodiagnosis on a Trypanosoma cruzi infected mouse, all but one became infected with the parasite.

  13. Comparative Meiotic Studies in Triatoma sordida (Stål and T. guasayana Wygodzinsky & Abalos (Reduviidae, Heteroptera

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    P Rebagliati

    1998-05-01

    Full Text Available Triatoma sordida and T. guasayana are competent Trypanosoma cruzi vectors, with overlapping distribution areas in Argentina. Both species are morphologically similar, and their immature stages are hard to discriminate. Cytogenetic studies in the genus Triatoma reveal scarce karyotypic variations, being 2n= 20 + XY the most frequent diploid number in males. In the present work the meiotic behaviour of different Argentinian populations of T. sordida and T. guasayana has been analyzed; the meiotic karyotype of both species has also been compared. The species differ in total chromosome area and in the relative area of the sex chromosomes. These meiotic karyotypic differences constitute an additional tool for the taxonomic characterization of T. sordida and T. guasayana. The analysis of an interpopulation hybrid of T. sordida (Brazil x Argentina reveals a regular meiotic behaviour, despite the presence of heteromorphic bivalents. Our observations support the hypothesis that karyotype variations through the gain or loss of heterochromatin can not be considered as a primary mechanism of reproductive isolation in Triatoma.

  14. Potential for entomopathogenic fungi to control Triatoma dimidiata (Hemiptera: Reduviidae, a vector of Chagas disease in Mexico

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    María Guadalupe Vázquez-Martínez

    2014-12-01

    Full Text Available Introduction The use of entomopathogenic fungi to control disease vectors has become relevant because traditional chemical control methods have caused damage to the environment and led to the development of resistance among vectors. Thus, this study assessed the pathogenicity of entomopathogenic fungi in Triatoma dimidiata. Methods Preparations of 108 conidia/ml of Gliocladium virens, Talaromyces flavus, Beauveria bassiana and Metarhizium anisopliae were applied topically on T. dimidiata nymphs and adults. Controls were treated with the 0.0001% Tween-80 vehicle. Mortality was evaluated and recorded daily for 30 days. The concentration required to kill 50% of T. dimidiata (LC50 was then calculated for the most pathogenic isolate. Results Pathogenicity in adults was similar among B. bassiana, G. virens and T. flavus (p>0.05 and differed from that in triatomine nymphs (p=0.009. The most entomopathogenic strains in adult triatomines were B. bassiana and G. virens, which both caused 100% mortality. In nymphs, the most entomopathogenic strain was B. bassiana, followed by G. virens. The native strain with the highest pathogenicity was G. virens, for which the LC50 for T. dimidiata nymphs was 1.98 x108 conidia/ml at 13 days after inoculation. Conclusions Beauveria bassiana and G. virens showed entomopathogenic potential in T. dimidiata nymphs and adults. However, the native G. virens strain presents a higher probability of success in the field, and G. virens should thus be considered a potential candidate for the biological control of triatomine Chagas disease vectors.

  15. Migration and Gene Flow Among Domestic Populations of the Chagas Insect Vector Triatoma dimidiata (Hemiptera: Reduviidae) Detected by Microsatellite Loci.

    Science.gov (United States)

    Stevens, Lori; Monroy, M Carlota; Rodas, Antonieta Guadalupe; Hicks, Robin M; Lucero, David E; Lyons, Leslie A; Dorn, Patricia L

    2015-05-01

    Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the parasite Trypanosoma cruzi in Central America, and particularly in Guatemala. Tr. cruzi is the causative agent of Chagas disease, and successful disease control requires understanding the geographic distribution and degree of migration of vectors such as T. dimidiata that frequently re-infest houses within months following insecticide application. The population genetic structure of T. dimidiata collected from six villages in southern Guatemala was studied to gain insight into the migration patterns of the insects in this region where populations are largely domestic. This study provided insight into the likelihood of eliminating T. dimidiata by pesticide application as has been observed in some areas for other domestic triatomines such as Triatoma infestans. Genotypes of microsatellite loci for 178 insects from six villages were found to represent five genetic clusters using a Bayesian Markov Chain Monte Carlo method. Individual clusters were found in multiple villages, with multiple clusters in the same house. Although migration occurred, there was statistically significant genetic differentiation among villages (FR T = 0.05) and high genetic differentiation among houses within villages (FSR = 0.11). Relatedness of insects within houses varied from 0 to 0.25, i.e., from unrelated to half-sibs. The results suggest that T. dimidiata in southern Guatemala moves between houses and villages often enough that recolonization is likely, implying the use of insecticides alone is not sufficient for effective control of Chagas disease in this region and more sustainable solutions are required. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Potential for entomopathogenic fungi to control Triatoma dimidiata (Hemiptera: Reduviidae), a vector of Chagas disease in Mexico.

    Science.gov (United States)

    Vázquez-Martínez, María Guadalupe; Cirerol-Cruz, Blanca Elva; Torres-Estrada, José Luis; López, Mario Henry Rodríguez

    2014-01-01

    The use of entomopathogenic fungi to control disease vectors has become relevant because traditional chemical control methods have caused damage to the environment and led to the development of resistance among vectors. Thus, this study assessed the pathogenicity of entomopathogenic fungi in Triatoma dimidiata. Preparations of 108 conidia/ml of Gliocladium virens, Talaromyces flavus, Beauveria bassiana and Metarhizium anisopliae were applied topically on T. dimidiata nymphs and adults. Controls were treated with the 0.0001% Tween-80 vehicle. Mortality was evaluated and recorded daily for 30 days. The concentration required to kill 50% of T. dimidiata (LC50) was then calculated for the most pathogenic isolate. Pathogenicity in adults was similar among B. bassiana, G. virens and T. flavus (p>0.05) and differed from that in triatomine nymphs (p=0.009). The most entomopathogenic strains in adult triatomines were B. bassiana and G. virens, which both caused 100% mortality. In nymphs, the most entomopathogenic strain was B. bassiana, followed by G. virens. The native strain with the highest pathogenicity was G. virens, for which the LC50 for T. dimidiata nymphs was 1.98 x108 conidia/ml at 13 days after inoculation. Beauveria bassiana and G. virens showed entomopathogenic potential in T. dimidiata nymphs and adults. However, the native G. virens strain presents a higher probability of success in the field, and G. virens should thus be considered a potential candidate for the biological control of triatomine Chagas disease vectors.

  17. Juvenile hormone III and nutrition effects on spermatogenesis in the 4th instar nymphs of Panstrongylus megistus (Hemiptera: Reduviidae

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    Maria José Costa Schuetz

    1991-03-01

    Full Text Available When 4th instar nymphs of Panstrongylus megistus are fed with a saturant blood meal, there is an intense proliferation of the spermatogonia. At the end of the intermoult, the older spermatogonial cysts differentiate into 1st primary spermatocyte cysts. In the nymphs deprived of the blood meal this evolution is not observed, but a small growth of the testicular follicles occurs, due to a few mitotic divisions. This growth is observed at least, until 25 days after ecdysis. Since day 15, an autolytic process starts in the older spermatogonial cysts. The presence of exogenous juvenile hormone III (JH III does not promote the development of the germ cells in the fasting insects. There is only a small growth of the testicular follicles and the autolytic process is also observed. In the precocious adults obtained by allatectomy or precocene II treatment, germ cells are observed in all development stages, except packed and elongated spermatozoa bundels.

  18. Chagas disease vector blood meal sources identified by protein mass spectrometry.

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    Judith I Keller

    Full Text Available Chagas disease is a complex vector borne parasitic disease involving blood feeding Triatominae (Hemiptera: Reduviidae insects, also known as kissing bugs, and the vertebrates they feed on. This disease has tremendous impacts on millions of people and is a global health problem. The etiological agent of Chagas disease, Trypanosoma cruzi (Kinetoplastea: Trypanosomatida: Trypanosomatidae, is deposited on the mammalian host in the insect's feces during a blood meal, and enters the host's blood stream through mucous membranes or a break in the skin. Identifying the blood meal sources of triatomine vectors is critical in understanding Chagas disease transmission dynamics, can lead to identification of other vertebrates important in the transmission cycle, and aids management decisions. The latter is particularly important as there is little in the way of effective therapeutics for Chagas disease. Several techniques, mostly DNA-based, are available for blood meal identification. However, further methods are needed, particularly when sample conditions lead to low-quality DNA or to assess the risk of human cross-contamination. We demonstrate a proteomics-based approach, using liquid chromatography tandem mass spectrometry (LC-MS/MS to identify host-specific hemoglobin peptides for blood meal identification in mouse blood control samples and apply LC-MS/MS for the first time to Triatoma dimidiata insect vectors, tracing blood sources to species. In contrast to most proteins, hemoglobin, stabilized by iron, is incredibly stable even being preserved through geologic time. We compared blood stored with and without an anticoagulant and examined field-collected insect specimens stored in suboptimal conditions such as at room temperature for long periods of time. To our knowledge, this is the first study using LC-MS/MS on field-collected arthropod disease vectors to identify blood meal composition, and where blood meal identification was confirmed with more

  19. Chagas disease vector blood meal sources identified by protein mass spectrometry.

    Science.gov (United States)

    Keller, Judith I; Ballif, Bryan A; St Clair, Riley M; Vincent, James J; Monroy, M Carlota; Stevens, Lori

    2017-01-01

    Chagas disease is a complex vector borne parasitic disease involving blood feeding Triatominae (Hemiptera: Reduviidae) insects, also known as kissing bugs, and the vertebrates they feed on. This disease has tremendous impacts on millions of people and is a global health problem. The etiological agent of Chagas disease, Trypanosoma cruzi (Kinetoplastea: Trypanosomatida: Trypanosomatidae), is deposited on the mammalian host in the insect's feces during a blood meal, and enters the host's blood stream through mucous membranes or a break in the skin. Identifying the blood meal sources of triatomine vectors is critical in understanding Chagas disease transmission dynamics, can lead to identification of other vertebrates important in the transmission cycle, and aids management decisions. The latter is particularly important as there is little in the way of effective therapeutics for Chagas disease. Several techniques, mostly DNA-based, are available for blood meal identification. However, further methods are needed, particularly when sample conditions lead to low-quality DNA or to assess the risk of human cross-contamination. We demonstrate a proteomics-based approach, using liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify host-specific hemoglobin peptides for blood meal identification in mouse blood control samples and apply LC-MS/MS for the first time to Triatoma dimidiata insect vectors, tracing blood sources to species. In contrast to most proteins, hemoglobin, stabilized by iron, is incredibly stable even being preserved through geologic time. We compared blood stored with and without an anticoagulant and examined field-collected insect specimens stored in suboptimal conditions such as at room temperature for long periods of time. To our knowledge, this is the first study using LC-MS/MS on field-collected arthropod disease vectors to identify blood meal composition, and where blood meal identification was confirmed with more traditional DNA

  20. Ensaios de inseticidas sistêmicos para animais, usando cães e triatomíneos Tests for systemic animal insecticides, using dogs and triatominae

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    Mario B. Aragão

    1981-04-01

    Full Text Available Foram incluídos em rações comerciais, e dados a cães, os seguintes inseticidas: Phoxim, Chlorphoxim, Themephos (Abate, Decametrina, Lindano e DDT. A ação inseticida, no sangue, foi testada com ninfas e adultos de Triatoma infestans. Foram obtidos bons resultados com o Phoxim e o Themephos. O Chlorphoxim e o Lindano, nas doses eficientes, mostraram-se pouco palatáveis e a Decametrina e o DDT, nas concentrações aceitas pelos cães, não tiveram ação letal sobre os insetos.The following insecticides were mixed with industrialized dog food: Phoxim, Chlorphoxim, Themephos (Abate, Decamethrin, Lindane, and DDT. The insecticidal effect in the blood was tested with Triatoma infestans nymphs and adults. Positive results were obtained with Phoxim and Themephos. Chlorphoxim and Lindane at efficient levels became unpalatable. Decamethrin and DDT had no lethal effect upon the insects at the levels of concentration tolerated by the dogs.

  1. Cytogenetics of Triatominae: III - A study on male sterility induced through hybridization of Triatoma sórdida and Triatoma pseudomaculata

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    Giorgio Schreiber

    1975-08-01

    Full Text Available Males from bilateral crosses between Triatoma sórdida and Triatoma pseudomaculata were unable to give offspring, as shown by subsequent backcrosses (BC between hybrid males and parental females. This kind of sterility indueed through interspecific hybridization seems to be due to lack of sperm migration from the bursa copulatrix to the spermateca, thus suggesting primarily failure on the part of hybrid males to produce and/or to incorporate male accessory secretions into the spermatophore bulb. Addicional proof that sterility induced in hybrid males is at the sperm level has been afforded by the spermatogenesis herein studied. The anomalous processes like; 1 prophases of spermatogonia with the chromosomes scattered in the cytoplasm, 2 first metaphases with unpaired tetrades, 3 spermatids differing in size and 4 spermatozoa of abnormal shape and generdlly of giant size, can be taken as an indicator of the degree of departure from the normal course of spermatogenesis.Os machos provenientes de cruzamentos bilaterais entre Triatoma sórdida e Triatoma pseudomaculata revelaram a incapacidade de produzir progênie, como se demonstra nos retrocruzamentos de machos híbridos com fêmeas das espécies paternas. Esta modalidade de esterilidade induzida através da hibridação interespecífica, parece ser devida à ausência de migração do esperma, determinada pela incapacidade dos híbridos machos produzirem a secreção opaca em suas glândulas acessórias e/ou incorporá-la à luz do espermatóforo. A prova adicional de que a incompatibilidade induzida em triatomíneos, através da hibridação inter específica, está no nível do esperma é fornecida pelo tipo anômalo de espermatogênese em híbridos aqui descrito, mostrando deste modo que: as prófases espermatogoniais têm os núcleos disruptos e os cromossomos espelhados no citoplasma. As primeiras metáfases meióticas têm as tétrades desemparelhadas. Os grupos de cromatídes assim obtidos formam espermatídes de tamanhos variáveis, maiores ou menores do que as espermatídes dos membros paternos. Os espermatozóides derivados são de formas e tamanhos anômalos, geralmente gigantes.

  2. Biology of triatominae (Reduviidade, Hemiptera from north of Formosa county (Goiás - Brazil. III: length of life cycle of Psammolestes tertius Lent and Jurberg 1965

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    Dalva A. Mello

    1977-08-01

    Full Text Available In the present work the life cycle of Psammolestes tertius was studied. The mean length, in days, fromeach stage was: 26.3 (± 1.7 (1st, 28.6 (± 1.8 (2nd, 28.4 (± 1.8 (3rd, 32.2 (± 1.9 (4th and 33.5 (± 5.8 (5th. The mean egg incubation period was 15.7 days (± 1.7. Overall mortality was 48.9% and egg viability was 65.7%.

  3. Ecology, evolution, and the long-term surveillance of vector-borne Chagas disease: a multi-scale appraisal of the tribe Rhodniini (Triatominae).

    Science.gov (United States)

    Abad-Franch, Fernando; Monteiro, Fernando A; Jaramillo O, Nicolás; Gurgel-Gonçalves, Rodrigo; Dias, Fernando Braga Stehling; Diotaiuti, Liléia

    2009-01-01

    Chagas disease incidence has sharply declined over the last decade. Long-term disease control will, however, require extensive, longitudinal surveillance systems capable of detecting (and dealing with) reinvasion-reinfestation of insecticide-treated dwellings by non-domiciliated triatomines. Sound surveillance design calls for reliable data on vector ecology, and these data must cover different spatial scales. We conducted a multi-scale assessment of ecological and evolutionary trends in members of the tribe Rhodniini, including (i) a macroscale analysis of Rhodniini species richness and composition patterns across the Americas, and (ii) a detailed, mesoscale case-study of ecological and behavioural trends in Rhodnius neglectus and R. nasutus. Our macroscale overview provides some comprehensive insights about key mechanisms/processes probably underlying ecological and genetic diversification in the Rhodniini. These insights translate into a series of testable hypotheses about current species distributions and their likely causes. At the landscape scale, we used geometric morphometrics to identify dubious specimens as either R. neglectus or R. nasutus (two near-sibling species), and studied palm tree populations of these two vector taxa in five geographical areas. The data suggest that deforestation and the associated loss of habitat and host diversity might increase the frequency of vector-human contact (and perhaps Trypanosoma cruzi infection rates in vectors). Surveillance in central-northeastern Brazil should prioritise deforested landscapes where large palm trees (e.g., Attalea, Mauritia, Copernicia, Acrocomia or Syagrus) occur near houses. We anticipate that, by helping define the distribution patterns and ecological preferences of each species, multi-scale research will significantly strengthen vector surveillance systems across Latin America.

  4. Insights into a hotspot in the Brasiliensis subcomplex (Hemiptera, Triatominae) by analysis of D2 domain of the nuclear gene 28S.

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    Guerra, A L; Alevi, K C C; Banho, C A; Oliveira, J; Rosa, J A; Azeredo-Oliveira, M T V

    2016-03-24

    The Brasiliensis subcomplex is a monophyletic group formed by the species Triatoma brasiliensis brasiliensis, T. b. macromelasoma, T. juazeirensis, T. melanica, and T. sherlocki. However, using cytogenetic data and experimental hybrid crosses, T. lenti and T. petrochiae were also grouped into this subcomplex. This study aims to analyze the properties of hotspot in the D2 domain of the nuclear gene 28S in all species of the Brasiliensis subcomplex as well as T. lenti and T. petrochiae. These species show two transversions at position 385 (G↔C and T↔G). We suggest that this mutation in haplotype 4 may be an initial molecular tool that supports the relationship of these species with the subcomplex. In addition to the transversion at haplotype 4, these species, aside from T. melanica, also possess a transversion at position 385 (G↔T) in haplotype 1. Thus, we describe the hotspot mutations of the D2 domain of the nuclear gene 28S for species in Brasiliensis subcomplex as follows: three transversions are present at position 385 of haplotypes 1 and 4, which are shared by members of the subcomplex as well as T. lenti and T. petrochiae. These transversions may be considered a synapomorphy between these species. However, we emphasize that new phylogenetic studies should be conducted to evaluate whether T. lenti and T. petrochiae are truly members of the Brasiliensis subcomplex.

  5. Cytogenetics of Triatominae: III - A study on male sterility induced through hybridization of Triatoma sórdida and Triatoma pseudomaculata

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    Giorgio Schreiber

    1975-08-01

    Full Text Available Males from bilateral crosses between Triatoma sórdida and Triatoma pseudomaculata were unable to give offspring, as shown by subsequent backcrosses (BC between hybrid males and parental females. This kind of sterility indueed through interspecific hybridization seems to be due to lack of sperm migration from the bursa copulatrix to the spermateca, thus suggesting primarily failure on the part of hybrid males to produce and/or to incorporate male accessory secretions into the spermatophore bulb. Addicional proof that sterility induced in hybrid males is at the sperm level has been afforded by the spermatogenesis herein studied. The anomalous processes like; 1 prophases of spermatogonia with the chromosomes scattered in the cytoplasm, 2 first metaphases with unpaired tetrades, 3 spermatids differing in size and 4 spermatozoa of abnormal shape and generdlly of giant size, can be taken as an indicator of the degree of departure from the normal course of spermatogenesis.

  6. Risks associated with dispersive nocturnal flights of sylvatic Triatominae to artificial lights in a model house in the northeastern plains of Colombia.

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    Jácome-Pinilla, David; Hincapie-Peñaloza, Eduwin; Ortiz, Mario I; Ramírez, Juan David; Guhl, Felipe; Molina, Jorge

    2015-11-19

    Control initiatives and continuous surveillance of vector-borne transmission have proved to be effective measures for diminishing the incidence of Chagas disease in endemic countries. However, the active dispersal of infected sylvatic adult triatomines by flight represents one of the main obstacles to eliminating domestic transmission. In order to determine the risk that active dispersal of sylvatic adult triatomines represents in Colombian northeastern plains, we quantified the distribution and abundance of triatomines in palm trees (primarily Attalea butyracea) using live bait traps. Directional light traps were used to estimate the frequency of sylvatic triatomine dispersal and their possible origin. Finally, the effect of environmental parameters and artificial light sources on the take-off of sylvatic Rhodnius prolixus was evaluated in field experiments. R. prolixus was found in 90 % of the palm trees that densely aggregated toward the northern portion of the study area. R. prolixus, and three other sylvatic triatomine species were found to actively disperse and were attracted to the directional light traps (Triatoma maculata, Panstrongylus geniculatus and Psammolestes arthuri). Temperature, relative humidity, wind speed and night luminosity did not affect the active dispersal of the triatomines which is higher the first two hours after sunset. Artificial lights from houses at 60 and 110 m played a key role in the directionality of the R. prolixus take-offs. Trypanosoma cruzi was isolated from R. prolixus, T. maculata and P. geniculatus and was genotyped as T. cruzi I, III and IV. Our results highlight the potential risk in Colombian northeastern plains of actively dispersing sylvatic triatomines and their role in the domestic introduction of Discrete Typing Units of T. cruzi associated to sylvatic foci of Chagas disease transmission.

  7. Morphometric Wings Similarity among Sylvatic and Domestic Populations of Triatoma infestans(Hemiptera: Reduviidae) from the Gran Chaco Region of Paraguay.

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    de Arias, Antonieta Rojas; Carbajal de la Fuente, Ana Laura; Gómez, Ana; Cecere, María Carla; Rolón, Miriam; Gómez, María Celeste Vega; Villalba, Cesia

    2017-08-01

    Despite sustained efforts for eliminating Triatoma infestans , reinfestation still persists in large part of the endemic area of Chagas disease from the Gran Chaco region. Sylvatic T. infestans populations seem to threat success of control programs of domestic T. infestans . In this study, we analyze whether T. infestans collected after a community-wide spraying were survivors or were immigrants from elsewhere using geometric morphometric tools. We used 101 right wings of female T. infestans captured before and after intervention program carried out in 12 de Junio and Casuarina, villages from Paraguayan Chaco, and in Puerto Casado during presprayed collection. There were no significant differences in wing size of domestic T. infestans between pre- and postspraying populations, and between domestic and sylvatic ones. When shape variables originating from postintervention individuals from 12 de Junio were introduced one by one into a discriminant analysis, the greatest weight (53%) was allocated to the sylvatic group. Furthermore, from the prespraying population, 25% were reallocated as postintervention individuals. Only 11% of the insects were reassigned to other groups Puerto Casado and Casuarina. These results suggest that postspraying individuals appear to have different origins. Half of the postspraying individuals from 12 de Junio were similar to the sylvatic ones and 25% of these were similar to those captured in the prespraying period. This remarkable morphometric wings similarity between sylvatic and domestic populations is new evidence suggesting that they could be highly related to each other in the Paraguayan Chaco; human-fed bugs from sylvatic area also support this.

  8. Host-Feeding Sources and Infection With Trypanosoma cruzi of Triatoma infestans and Triatoma eratyrusiformis (Hemiptera: Reduviidae) From the Calchaqui Valleys in Northwestern Argentina.

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    Cecere, M C; Leporace, M; Fernández, M P; Zárate, J E; Moreno, C; Gürtler, R E; Cardinal, M V

    2016-05-01

    We assessed the prevalence of infection with Trypanosoma cruzi, parasite genotypes (discrete typing units, DTUs), and the host-feeding sources of domestic and peridomestic Triatoma infestans Klug and Triatoma eratyrusiformis Del Ponte in eight rural communities of the subandean Calchaqui valleys in northwestern Argentina. We sought to analyze their epidemiological role in the context of routine vector surveillance and control actions. Infection with T. cruzi was determined by optic microscopy or polymerase chain reaction (PCR) amplification of the hypervariable region of kinetoplast DNA minicircles. Parasite genotypes were identified through a multi PCR-based strategy. Bloodmeal contents were tested with a direct ELISA assay against nine antisera. Human sleeping quarters (domiciles) and peridomestic dry-shrub fences concentrated most of the T. infestans and T. eratyrusiformis infected with T. cruzi, respectively. The most frequent host-feeding sources of T. infestans were chickens (73.1%) in peridomiciles and humans (73.3%) in domiciles, whereas T. eratyrusiformis fed more often on cavid rodents (92.6%), which thrived in the dry-shrub fences. The main T. cruzi DTU identified in both vectors was T. cruzi I (TcI). Triatoma eratyrusiformis was implicated in the local circulation of TcI among cavies and perhaps mice, but infection with other typically domestic DTUs (TcVI and TcII/TcV/TcVI) indicated overlap between (peri)domestic transmission cycles in both vector species. Because dry-shrub fences were not targeted for routine insecticide spraying, they may act as sources of (peri)domestic reinfestation. Triatoma eratyrusiformis is an emergent secondary vector of T. cruzi and plays a significant role in the local transmission of T. cruzi. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. House Reinfestation With Triatoma infestans (Hemiptera: Reduviidae) After Community-Wide Spraying With Insecticides in the Argentine Chaco: A Multifactorial Process.

    Science.gov (United States)

    Provecho, Yael M; Gaspe, M Sol; Fernández, M Del Pilar; Gürtler, Ricardo E

    2017-05-01

    We investigated the dynamics and underlying causes of house (re)infestation with Triatoma infestans (Klug 1834) after a community-wide residual spraying with pyrethroids in a well-defined rural section of Pampa del Indio municipality (northeastern Argentina) over a 4-yr period. House infestation was assessed by timed manual searches, during insecticide applications, and by opportunistic householders' bug collections. All reinfested houses were selectively re-sprayed with insecticides. The resident population comprised Qom (66.6%) and Creole (33.4%) households, whose sociodemographic profiles differed substantially. The prevalence of house infestation dropped, less than expected, from 20.5% at baseline to 5.0% at 14 months postspraying (MPS), and then fluctuated between 0.8 and 4.2% over 21-51 MPS. Postspraying house infestation was positively and highly significantly associated with prespraying infestation. Most of the foci detected over 14-21 MPS were considered persistent (residual), some of which were moderately resistant to pyrethroids and were suppressed with malathion. Infestation patterns over 27-51 MPS suggested bug invasion from internal or external foci, but the sources of most findings were unaccounted for. Local spatial analysis identified two hotspots of postspraying house infestation. Using multimodel inference with model averaging, we corroborated that baseline domestic infestation was closely related to refuge availability, housing quality, and occurrence of peridomestic infestation. The diminished effectiveness of single pyrethroid treatments, partly attributable to moderate resistance compounded with rather insensitive vector detection methods and poor housing conditions, contributed to vector persistence. Improved control strategies combined with broad social participation are needed for the sustainable elimination of vector-borne human Chagas disease from the Gran Chaco. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Is imidacloprid an effective alternative for controlling pyrethroid-resistant populations of Triatoma infestans (Hemiptera: Reduviidae) in the Gran Chaco ecoregion?

    Science.gov (United States)

    Carvajal, Guillermo; Picollo, María Inés; Toloza, Ariel Ceferino

    2014-09-01

    The prevention of Chagas disease is based primarily on the chemical control of Triatoma infestans (Klug) using pyrethroid insecticides. However, high resistance levels, correlated with control failures, have been detected in Argentina and Bolivia. A previous study at our laboratory found that imidacloprid could serve as an alternative to pyrethroid insecticides. We studied the delayed toxicity of imidacloprid and the influence of the blood feeding condition of the insect on the toxicity of this insecticide; we also studied the effectiveness of various commercial imidacloprid formulations against a pyrethroid-resistant T. infestans population from the Gran Chaco ecoregion. Variations in the toxic effects of imidacloprid were not observed up to 72 h after exposure and were not found to depend on the blood feeding condition of susceptible and resistant individuals. Of the three different studied formulations of imidacloprid on glass and filter paper, only the spot-on formulation was effective. This formulation was applied to pigeons at doses of 1, 5, 20 and 40 mg/bird. The nymphs that fed on pigeons treated with 20 mg or 40 mg of the formulation showed a higher mortality rate than the control group one day and seven days post-treatment (p < 0.01). A spot-on formulation of imidacloprid was effective against pyrethroid-resistant T. infestans populations at the laboratory level.

  11. Cytogenetic and morphologic approaches of hybrids from experimental crosses between Triatoma lenti Sherlock & Serafim, 1967 and T. sherlocki Papa et al., 2002 (Hemiptera: Reduviidae).

    Science.gov (United States)

    Mendonça, Vagner José; Alevi, Kaio Cesar Chaboli; Medeiros, Lívia Maria de Oliveira; Nascimento, Juliana Damieli; de Azeredo-Oliveira, Maria Tercília Vilela; da Rosa, João Aristeu

    2014-08-01

    The reproductive capacity between Triatoma lenti and Triatoma sherlocki was observed in order to verify the fertility and viability of the offspring. Cytogenetic, morphological and morphometric approaches were used to analyze the differences that were inherited. Experimental crosses were performed in both directions. The fertility rate of the eggs in crosses involving T. sherlocki females was 65% and 90% in F1 and F2 offspring, respectively. In reciprocal crosses, it was 7% and 25% in F1 and F2 offspring, respectively. The cytogenetic analyses of the male meiotic process of the hybrids were performed using lacto-acetic orcein, C-banding and Feulgen techniques. The male F1 offspring presented normal chromosome behavior, a finding that was similar to those reported in parental species. However, cytogenetic analysis of F2 offspring showed errors in chromosome pairing. This post-zygotic isolation, which prevents hybrids in nature, may represent the collapse of the hybrid. This phenomenon is due to a genetic dysregulation that occurs in the chromosomes of F1. The results were similar in the hybrids from both crosses. Morphological features, such as color and size of connexive and the presence of red-orange rings on the femora, were similar to T. sherlocki, while wins size was similar to T. lenti in F1 offspring. The eggshells showed characteristics that were similar to species of origin, whereas the median process of the pygophore resulted in intermediate characteristics in the F1 and a segregating pattern in F2 offspring. Geometric morphometric techniques used on the wings showed that both F1 and F2 offspring were similar to T. lenti. These studies on the reproductive capacity between T. lenti and T. sherlocki confirm that both species are evolutionarily closed; hence, they are included in the brasiliensis subcomplex. The extremely reduced fertility observed in the F2 hybrids confirmed the specific status of the species that were analyzed. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Application of Inter-Simple Sequence Repeat Markers in the Analysis of Populations of the Chagas Disease VectorTriatoma infestans(Hemiptera, Reduviidae).

    Science.gov (United States)

    Pérez de Rosas, Alicia R; Restelli, María F; Fernández, Cintia J; Blariza, María J; García, Beatriz A

    2017-03-01

    AbstractHere we apply inter-simple sequence repeat (ISSR) markers to explore the fine-scale genetic structure and dispersal in populations of Triatoma infestans . Five selected primers from 30 primers were used to amplify ISSRs by polymerase chain reaction. A total of 90 polymorphic bands were detected across 134 individuals captured from 11 peridomestic sites from the locality of San Martín (Capayán Department, Catamarca Province, Argentina). Significant levels of genetic differentiation suggest limited gene flow among sampling sites. Spatial autocorrelation analysis confirms that dispersal occurs on the scale of ∼469 m, suggesting that insecticide spraying should be extended at least within a radius of ∼500 m around the infested area. Moreover, Bayesian clustering algorithms indicated genetic exchange among different sites analyzed, supporting the hypothesis of an important role of peridomestic structures in the process of reinfestation.

  13. Morphological, biological and molecular characterization of three strains of Trypanosoma cruzi Chagas, 1909 (Kinetoplastida, Trypanosomatidae) isolated from Triatoma sordida (Stal) 1859 (Hemiptera, Reduviidae) and a domestic cat

    Science.gov (United States)

    RIMOLDI, ALINE; TOMÉ ALVES, RENATA; AMBRÓSIO, DANIELA LUZ; FERNANDES, MARIA ZENAIDE TITA; MARTINEZ, ISABEL; DE ARAÚJO, RENATO FREITAS; CICARELLI, REGINA MARIA BARRETO; DA ROSA, JOÃO ARISTEU

    2012-01-01

    SUMMARY A study was conducted of the biological, morphological and molecular characters of 3 strains of Trypanosoma cruzi (SI5, SI8 and SIGR3) isolated from specimens of Triatoma sordida collected in Santo Inácio and a domestic cat. In order to carry out the study, the following parameters were evaluated: pre-patent period, parasitaemia curves, morphology of the parasites, mortality rates, histopathological lesions and molecular typing. The strains presented variable pre-patent periods, low parasitaemia and no animal mortality. The morphological study of trypomastigotes showed a predominance of intermediate-width and short-length forms, as well as low nuclear index. Epimastigotes presented a low nuclear index, intermediate-width forms in strains SI5 and SI8, and large-width forms in SIGR3. A shorter length could be noted in strains SI8 and SIGR3, whereas SI5 displayed an intermediate length. The histopathological study did not detect amastigote nests in tissues. The amplification of the divergent domain of 24Sα rRNA, HSP60 and GPI genes of strains SI5, SI8 and SIGR3 classified the 3 strains into Group II. Biological parameters made it possible to classify the strains isolated in Santo Inácio (BA) into Biodeme III, Zymodeme 1 and Group II of T. cruzi. PMID:22217619

  14. Alberprosenia malheiroi Serra, Atzingen & Serra, 1987 (Hemiptera, Reduviidae: redescrição e bionomia Alberprosenia malheiroi Serra, Atzingen & Serra, 1987 (Hemiptera, Rediviidae: redescription and bionomics

    Directory of Open Access Journals (Sweden)

    Rodolfo U. Carcavallo

    1995-12-01

    Full Text Available Sobre Alberprosenia malheiroi n. sp. deu-se a conhecer uma diagnose resumida em 1980, porém sem valor bibliográfico. Em 1987 publicou-se a mesma diagnose anexando uma foto e alguns comentários, porém sem realizar uma descrição formal. Descreve-se para esta espécie, os adultos, os estádios imaturos, determina-se a série sintípica e apresenta-se dados bionômicos e de criação em insetário. As diferenças mais evidentes com A. goyovargasi, a única espécie que se conhecia do gênero até então, são a coloração geral negra, o espaço interocular maior que o tamanho de um olho visto dorsalmente, os tubérculos do colar com o ápice agudo e o tamanho maior, na nova espécie, quase o dobro do da primeira espécie. Os ovos são pequenos, fixados ao substrato em grupos de 3 ou 4, elipsóides, não achatados lateralmente, com o opérculo proeminente, convexo, sem estruturas evidentes. As ninfas apresentam em todos os estádios caracteres típicos do gênero e da tribo, com região anteocular menos longa que a post-ocular e característica pilosidade do tegumento que vai se acentuando a cada estádio. A. malheiroi n. sp. foi capturado em ecótopos silvestres em palmeiras em floresta no Estado do Pará, associados com morcegos ou aves. Nenhum dos exemplares estava infectado com Trypanosoma cruzi. Esses triatomíneos foram mantidos em insetários a ± 25°C e ± 60% UR, são insetos ágeis e voam com relativa facilidade. Alimentaram-se bem em pombos e morcegos e não aceitaram alimentação em ratos, camundongos ou hamsters. O período de incubação dos ovos foi em média treze dias e o tempo de evolução do período ninfal foi em média cento e trinta e dois dias.Alberprosenia malheiroi n. sp. first became known through an informal publication of a paper submitted a Congress, in 1980. The same diagnosis with a photograph was published in 1987, but no formal description has yeet been made. The present authors describe adults and immature instars, establish a sintypical series and introduce bionomic data and data on the rearing of this species in insectary.The most evident differences between A. malheiroi n. sp. and A. goyovargasi, the former generic species, are the general colour pattern which is completely black; the interocular area, wider than an eye in dorsal view; the acute apex in collar tubercules and the significantly larger size, almost double that of the latter specie. The eggs are small attach themselves to the substratum in groups of either 3 or 4, are elipsoid with no lateral flattening, having a convex and prominent operculum, without conspicuous structures. Nymphs have the typical tribal and generic characteristics in each stage, the anteocular region being shorter than the postocular one. Pilosity appears in the second instar and becomes more evident with instar development. A. malheiroi n. sp. was captured in a forest, in wild (palm-tree ecotopes associated with bats or birds, in the State of Para, Brazil. Trypanosoma cruzi was not found in any specimens. These triatomines were reared in ± 25°C and ± 60 % RH, the insects are quick and fly without difficulty. They fed well on pigeons and bats but not on rats, mice or hamsters. The eggs incubation period was thirteen days on average, and the evolution time of the nymphal period was a hundred and thirty two days on average.

  15. Synanthropic triatomines (Hemiptera, Reduviidae) in the state of Pernambuco, Brazil: geographical distribution and natural Trypanosoma infection rates between 2006 and 2007.

    Science.gov (United States)

    Silva, Maria Beatriz Araújo; Barreto, Ana Virgínia Matos Sá; Silva, Helker Albuquerque da; Galvão, Cleber; Rocha, Dayse; Jurberg, José; Gurgel-Gonçalves, Rodrigo

    2012-02-01

    The present study shows a descriptive analysis of triatomine occurrence and its natural Trypanosoma infection rates in the state of Pernambuco, Brazil, between 2006 and 2007. Entomological data for the species, such as specimens captured in both intra and peridomiciles and natural infection index, were obtained via domiciliary capture in 147 municipalities from 11 Regional Managements of Health. The database was obtained from a sample of insects (100% infected and 20% non-infected) sent to the Central Laboratory of Pernambuco. A total of 18,029 triatomines were analyzed from 138 municipalities of the state. Triatoma pseudomaculata (35%), Triatoma brasiliensis (34%), and Panstrongylus lutzi (25%) were the most captured species. These species also showed a widespread geographical distribution in the state. Panstrongylus megistus, Triatoma petrocchiae, Triatoma melanocephala, Triatoma sordida, Rhodnius nasutus, Rhodnius neglectus, and Triatoma infestans showed more limited geographical distribution and lower relative abundance. The parasitological research showed that 8.8% of the triatomines were naturally infected with flagellates morphologically similar to Trypanosoma cruzi and 91.3% of them were captured inside houses in 113 municipalities. P. lutzi showed the highest rates of natural infection. After the control of T. infestans, synanthropic species, such as T. brasiliensis, T. pseudomaculata, and P. lutzi, maintain the risk of T. cruzi transmission to humans in the state of Pernambuco. These species are widely distributed, and infected specimens have been found inside houses. Thus, an enhanced surveillance and vector control of Chagas disease is recommended in Pernambuco.

  16. Is imidacloprid an effective alternative for controlling pyrethroid-resistant populations of Triatoma infestans (Hemiptera: Reduviidae) in the Gran Chaco ecoregion?

    Science.gov (United States)

    Carvajal, Guillermo; Picollo, María Inés; Toloza, Ariel Ceferino

    2014-01-01

    The prevention of Chagas disease is based primarily on the chemical control of Triatoma infestans (Klug) using pyrethroid insecticides. However, high resistance levels, correlated with control failures, have been detected in Argentina and Bolivia. A previous study at our laboratory found that imidacloprid could serve as an alternative to pyrethroid insecticides. We studied the delayed toxicity of imidacloprid and the influence of the blood feeding condition of the insect on the toxicity of this insecticide; we also studied the effectiveness of various commercial imidacloprid formulations against a pyrethroid-resistant T. infestans population from the Gran Chaco ecoregion. Variations in the toxic effects of imidacloprid were not observed up to 72 h after exposure and were not found to depend on the blood feeding condition of susceptible and resistant individuals. Of the three different studied formulations of imidacloprid on glass and filter paper, only the spot-on formulation was effective. This formulation was applied to pigeons at doses of 1, 5, 20 and 40 mg/bird. The nymphs that fed on pigeons treated with 20 mg or 40 mg of the formulation showed a higher mortality rate than the control group one day and seven days post-treatment (p < 0.01). A spot-on formulation of imidacloprid was effective against pyrethroid-resistant T. infestans populations at the laboratory level. PMID:25141281

  17. Alimentación y defecación en triatominos del género Rhodnius (Hemiptera: Reduviidae alimentados con sangre humana

    Directory of Open Access Journals (Sweden)

    E. Aldana

    2001-06-01

    Full Text Available Se estudió el comportamiento alimenticio y de defecación de Rhodnius prolixus Stal, 1859, R. robustus Larrousse, 1927, R. neivai Lent, 1953 y R. pictipes Stal, 1872 alimentados artificialmente con sangre humana en condiciones de laboratorio. La ninfa I de todas las especies no defecaron en la primera media hora después de haber iniciado la ingesta. R. pictipes no se acercó a picar en el alimentador artificial aunque si lo hizo cuando el alimento se ofreció directamente sobre el cuerpo humano. Las ninfas y adultos de R. prolixus mostraron índices de defecación (ID superiores a los correspondientes de las otras especies, y la ninfa III presentó el mayor ID=1.62. La mayoría de individuos de todos los estadíos de desarrollo aceptaron el alimento en un tiempo entre 0 y 3 min y se alimentaron en menos de 15 minutos.Feeding and defecaction behavior of Rhodnius prolixus Stal, 1859, R. robustus Larrousse, 1927, R. neivai Lent, 1953 and R. pictipes Stal, 1872, artificially fed on human blood, were studied under laboratory conditions. In all species, first instar nymphs did not defecate in the first 30 minutes after feeding. R. pictipes did not accept artificial feeding but fed directly on humans. Nymph and adult R. prolixus had a higher defecation index (DI than other species; third instar nymphs had the highest DI=1.62. In all instars, most individuals accepted the food in £ 3 minutes and finished feeding in less than 15 minutes.

  18. Geographical Variation of Deltamethrin Susceptibility of Triatoma infestans (Hemiptera: Reduviidae) in Argentina With Emphasis on a Resistant Focus in the Gran Chaco.

    Science.gov (United States)

    Fronza, G; Toloza, A C; Picollo, M I; Spillmann, C; Mougabure-Cueto, G A

    2016-07-01

    Chagas disease is one of the most important parasitic infections in Latin America. The main vector of the protozoan Trypanosoma cruzi in America is Triatoma infestans, a blood-sucking triatomine bug who is widely distributed in the Gran Chaco ecoregion. Control programs in endemic countries are focused in the elimination of triatomine vectors with pyrethroid insecticides. However, chemical control has failed in the Gran Chaco over the last two decades because of several factors. Previous studies have reported the evolution of different levels of resistance to deltamethrin in Tri. infestans Recently, very high resistance has been found in the central area of the Argentine Gran Chaco. However, the origin and the extension of this remarkably resistant focus remain unknown. The aim of this study was to evaluate the geographical variation of deltamethrin susceptibility of Tri. infestans in different endemic provinces of Argentina, with emphasis in the center of the Argentine Gran Chaco ecoregion where this main vector has not been reduced. Populations of Mendoza, San Juan, Santiago del Estero, and Tucumán provinces were all susceptible. Resistant populations were only detected in the province of Chaco, where a mosaic resistant focus was described at the Güemes Department. It was characterized into three pyrethroid resistance categories: susceptible, low, and highly resistant populations. We found the populations with the highest resistance levels to deltamethrin, with resistant ratios over 1000. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Variación del fenotipo antenal de poblaciones del domicilio, peridomicilio y silvestres de Triatoma dimidiata (Hemiptera: Reduviidae en Santander, Colombia

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    Corina María Arroyo

    2007-01-01

    Conclusiones. El fenotipo de sensilla antenal fue útil en la diferenciación intraespecífica de Triatoma dimidiata en diferentes hábitats. Las diferencias en hembras ponen de manifiesto nuevos arreglos sensoriales para la explotación del hábitat a diferencia de los machos, que por su mayor capacidad de dispersión, no se diferenciaron entre los ecotopos. La similitud entre hembras de zona urbana, con hembras de peridomicilio rural permite proponer al fenotipo antenal como un sencillo y eficiente indicador para la determinación del origen de triatominos que intentan colonizar nuevos hábitats.

  20. Effect of sequential heat and cold shocks on nuclear phenotypes of the blood-sucking insect, Panstrongylus megistus (Burmeister (Hemiptera, Reduviidae

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    Garcia Simone L

    2002-01-01

    Full Text Available Thermal shocks induce changes in the nuclear phenotypes that correspond to survival (heterochromatin decondensation, nuclear fusion or death (apoptosis, necrosis responses in the Malpighian tubules of Panstrongylus megistus. Since thermal tolerance increased survival and molting rate in this species following sequential shocks, we investigated whether changes in nuclear phenotypes accompanied the insect survival response to sequential thermal shocks. Fifth instar nymphs were subjected to a single heat (35 or 40°C, 1 h or cold (5 or 0°C, 1 h shock and then subjected to a second shock for 12 h at 40 or 0°C, respectively, after 8, 18, 24 and 72 h at 28°C (control temperature. As with specimen survival, sequential heat and cold shocks induced changes in frequency of the mentioned nuclear phenotypes although their patterns differed. The heat shock tolerance involved decrease in apoptosis simultaneous to increase in cell survival responses. Sequential cold shocks did not involve cell/nuclear fusion and even elicited increase in necrosis with advancing time after shocks. The temperatures of 40 and 0ºC were more effective than the temperatures of 35 and 5ºC in eliciting the heat and cold shock tolerances, respectively, as shown by cytological analysis of the nuclear phenotypes. It is concluded that different sequential thermal shocks can trigger different mechanisms of cellular protection against stress in P. megistus, favoring the insect to adapt to various ecotopes.

  1. Deltamethrin pyrethroid susceptibility characterization of Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae populations in the Northern Region of Minas Gerais, Brazil

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    Grasielle Caldas DÁvila Pessoa

    2014-08-01

    Full Text Available Introduction Triatoma sordida is the most captured Triatomine species in the Brazilian artificial environment. In 2008, the discovery of three Triatomine populations with altered susceptibilities to deltamethrin highlighted the importance of investigating the genetic potential for resistance in triatomines. The purpose of this study was to characterize the susceptibility to deltamethrin of peridomestic T. sordida populations in Minas Gerais, Brazil. Methods A susceptibility reference lineage derived from Uberaba, Minas Gerais, Brazil was used. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 of the susceptibility reference lineage. Results Susceptibility profile characterization of T. sordida populations revealed resistance ratios (RR50s ranging from 0.42 to 3.94. The percentage mortality in response to the diagnostic dose varied from 70% to 100%. A comparison of the results obtained in the quantitative and qualitative assays demonstrated a lack of correspondence for some populations. Conclusions We demonstrated that only T. sordida populations that present a RR50>1.0 have altered susceptibility, and the execution of simultaneous field and laboratory tests is required to understand the actual effect of vector control. A possible cause of the observed resistance ratios might be the continuous use of pyrethroids in Brazil since the 1980s.

  2. Ciclo de vida de Triatoma dimidiata Latreille, 1811 (Hemiptera, Reduviidae en condiciones de laboratorio: producción de ninfas para ensayos biológicos

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    Marlene Reyes

    2009-03-01

    Conclusión. T. dimidiata presentó un tiempo de desarrollo intermedio entre los triatominos con amplio rango para algunos individuos, posiblemente debido a la irregularidad en su alimentación. La identificación de un rango de peso homogéneo después de 22 días de ayuno con gran producción de ninfas de V estadio, facilita la aplicación de protocolos estandarizados para establecer criterios de selección de compuestos insecticidas utilizables en los programas de control.

  3. Comparación de métodos para la captura de triatominos (Hemiptera: Reduviidae en palmas Attalea butyracea en los Llanos Orientales de Colombia

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    Víctor Manuel Angulo

    2013-12-01

    Full Text Available Introducción. El estudio de los triatominos en sus ecótopos naturales tiene gran significado en la epidemiología de la enfermedad de Chagas. La recolección de insectos vivos y su establecimiento en insectarios permite realizar incontables estudios. Por ello se necesitan métodos efectivos para la captura de triatominos silvestres, especialmente especies intrusas como Rhodnius prolixus. Objetivo. Comparar cuatro métodos para la captura de triatominos en palmas para medir su efectividad. Materiales y métodos. El estudio se llevó a cabo en la localidad de Maní, departamento de Casanare, Colombia, con predominio de Attalea butyracea. Se compararon cuatro metodologías en 67 palmas: trampas con cebo vivo, búsqueda directa en palmas, tala y disección. Resultados. Los métodos fueron efectivos para recolectar ejemplares juveniles y adultos. La tala y la búsqueda manual mostraron los mayores índices de infestación (100 % y 83,33 %. La trampa Angulo mostró mayores índices de hacinamiento (4,93, densidad (3,76, rango de abundancia (1-13 e índice adulto/ninfa (0,22. La tala y la disección fue el método que significativamente recolectó más triatominos en comparación con los otros (p0,05. Conclusiones. Aunque la tala fue el mejor método para la recolección del mayor número de triatominos, los métodos con el cebo vivo con adhesivos o refugios para atrapar los insectos, fueron una buena alternativa. Entre ellos, la trampa Angulo mostró mejores resultados y evitó la exposición del investigador al riesgo y la intervención de ecotopos naturales.   doi: http://dx.doi.org/10.7705/biomedica.v33i4.835

  4. Natural lectin activity in the haemolymph of Panstrogylus megistus (Heteroptera: Reduvidae Atividade lectínica na hemolinfa de Panstrongylus megistus (Heteroptera: Reduviidae

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    Y. M. Gomes

    1988-12-01

    Full Text Available The haemolymph of Panstrongylus megistus showed a natural lectin activity for a wide range of vertebrate erythocytes. Agglutination was observed against all vertebrate erythrocytes tested (human ABO, duck, rabbit, mouse, sheep, chicken and cow. Cow erythrocytes showed the lowest titre. Concerning human erythrocytes, the lectin activity was similar in the types A+,B+ and AB+ while the highest activity was observed in the type O+. Determination of minimal inhibitory concentrations was carried out with human erythrocytes type O+. Agglutination was inhibited by several carbohydrates (rhamnose. D-galatose, raffinose, D-lactose and D-fucose. Rhamnose wasreported as the strongest inhibitor (0.78mM. The results suggest the presence of more than one lection in the haemolymph of P. megistus.A hemolinfa de Panstrongylus megistus mostrou uma atividade lectínica natural para eritrócitos de vários vertebrados e não mostrou especificidade para os diversos tipos de eritrócitos testados (humano ABO, pato, coelho,c amundongo,carneiro, galinha e boi. Com relação aos eritrócitos humanos a atividade lectínica foi similar nos tipos A+, B+ e AB+ enquanto a atividade mais alta foi observada no tipo O+. O título de aglutinação entre eritrócitos animais não mostrou diferença apreciável, excluindo eritrócitos de boi, que apresentaram o título mmais baixo. A determinação da concentração mínima de inibição foi realizada com eritrócitos humanos O+. A aglutinação foi inibida por vários carboidratos (ramnose, D-dalactose, rafinose, D-lactose e D-fucose. A ramnose foi o inibidor mais potente (0,78 mM. Os resultados sugerem a presença de mais de uma lectina na hemolinfa de P. megistus.

  5. Blood meal sources of wild and domestic Triatoma infestans (Hemiptera: Reduviidae) in Bolivia: connectivity between cycles of transmission of Trypanosoma cruzi.

    Science.gov (United States)

    Buitrago, Rosio; Bosseno, Marie-France; Depickère, Stéphanie; Waleckx, Etienne; Salas, Renata; Aliaga, Claudia; Barnabé, Christian; Brenière, Simone Frédérique

    2016-04-18

    Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries. These wild populations are suspected of affecting the success of insecticide control campaigns being carried out in South America. To assess the risk that these T. infestans populations pose to human health, it is helpful to determine blood meal sources. In the present work, blood meals were identified in various Bolivian wild T. infestans populations and in three specific areas, in both wild and intra-peridomestic populations to assess the links between wild and domestic cycles of T. cruzi transmission. PCR-HDA and sequencing of Cytb gene were used to identify these blood meal sources. Fourteen vertebrate species were identified as wild blood meal sources. Of those, the most prevalent species were two Andean endemic rodents, Octodontomys gliroides (36%) and Galea musteloides (30%), while humans were the third most prevalent source (18.7%). Of 163 blood meals from peridomestic areas, more than half were chickens, and the others were generally domestic animals or humans. Interestingly, blood from wild animals was identified in triatomines captured in the peridomestic and domestic environment, and blood from domestic animals was found in triatomines captured in the wild, revealing links between wild and domestic cycles of T. cruzi transmission. The current study suggests that wild T. infestans attack humans in the wild, but is also able to bite humans in domestic settings before going back to its natural environment. These results support the risk to human health posed by wild populations of T. infestans.

  6. Natural infection of triatomines (Hemiptera: Reduviidae) by trypanosomatids in two different environments in the municipality of Ouro Preto do Oeste, State of Rondônia, Brazil.

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    Meneguetti, Dionatas Ulisses de Oliveira; Trevisan, Olzeno; Camargo, Luís Marcelo Aranha; Rosa, Renato Moreira

    2012-06-01

    This study analyzed the occurrence and the contamination of triatomines by trypanosomatids in Orbignya speciosa (babassu) specimens in the State of Rondônia, Brazil, in two different environments (pasture and woods). Capture of triatomines on babassus and microscopic search for trypanosomatids in their digestive tube were carried out. Four hundred ninety-four (494) specimens were captured (Rhodnius prolixus and R.robustus), of which 35.6% of the triatomines were positive for trypanosomatids. The high index of natural infection along with the abundance of triatomines points out to the necessity to create an epidemiological surveillance system to monitor vector-borne transmission and deepen the studies on the ecology of such vectors in the Amazon.

  7. Synanthropic triatomines (Hemiptera, Reduviidae in the state of Pernambuco, Brazil: geographical distribution and natural Trypanosoma infection rates between 2006 and 2007

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    Maria Beatriz Araújo Silva

    2012-02-01

    Full Text Available INTRODUCTION: The present study shows a descriptive analysis of triatomine occurrence and its natural Trypanosoma infection rates in the state of Pernambuco, Brazil, between 2006 and 2007. METHODS: Entomological data for the species, such as specimens captured in both intra and peridomiciles and natural infection index, were obtained via domiciliary capture in 147 municipalities from 11 Regional Managements of Health. The database was obtained from a sample of insects (100% infected and 20% non-infected sent to the Central Laboratory of Pernambuco. RESULTS: A total of 18,029 triatomines were analyzed from 138 municipalities of the state. Triatoma pseudomaculata (35%, Triatoma brasiliensis (34%, and Panstrongylus lutzi (25% were the most captured species. These species also showed a widespread geographical distribution in the state. Panstrongylus megistus, Triatoma petrocchiae, Triatoma melanocephala, Triatoma sordida, Rhodnius nasutus, Rhodnius neglectus, and Triatoma infestans showed more limited geographical distribution and lower relative abundance. The parasitological research showed that 8.8% of the triatomines were naturally infected with flagellates morphologically similar to Trypanosoma cruzi and 91.3% of them were captured inside houses in 113 municipalities. P. lutzi showed the highest rates of natural infection. CONCLUSIONS: After the control of T. infestans, synanthropic species, such as T. brasiliensis, T. pseudomaculata, and P. lutzi, maintain the risk of T. cruzi transmission to humans in the state of Pernambuco. These species are widely distributed, and infected specimens have been found inside houses. Thus, an enhanced surveillance and vector control of Chagas disease is recommended in Pernambuco.

  8. Entomological and ecological aspects of six sylvatic species of triatomines (Hemiptera, Reduviidae from the collection of the National Biodiversity Institute of Costa Rica, Central America

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    Rodrigo Zeledón

    2001-08-01

    Full Text Available A total of 797 specimens of wild adult triatomines, belonging to six species from the entomological collections of the Costa Rican National Biodiversity Institute, was studied from the standpoint of their relative abundance, as reflected by light traps, distribution in the country, seasonal variations and climatic and altitudinal preferences. Triatoma dimidiata was the most abundant species (32.9% of the total specimens, with a very extensive distribution in different ecological zones, being more common between 100 to 400 m above sea level mainly at the end of the dry season. T. dispar was the third in frequency (21.5%, with narrower distribution, more abundant between 600 to 800 m and scarce during the dry season. Panstrongylus geniculatus and P. rufotuberculatus, second and fourth in frequency (22.1% and 15.1%, respectively, were widely distributed on both the Pacific and Caribbean basins, the former being more common between 80 to 270 m all year round and the latter below 800 m mainly during the first semester. Eratyrus cuspidatus which represented only 4.9% of the insects, was also present on both basins mainly below 200 m with a tendency to be scarce during certain months of the year, and was found in all types of ecological zones. Finally, Rhodnius pallescens, the least abundant species (3.6% was restricted to very humid areas below 20 m, on the north side and Caribbean basin. With the exception of R. pallescens, males were more commonly found than females. Some epidemiological implications related to the six species are discussed.

  9. Distribución geográfica del género Pimeliaphilus Trägårdh (Acari: Prostigmata asociados a triatominos (Hemiptera: Reduviidae

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    Gerardo A. MARTI

    2017-01-01

    Full Text Available Se brinda un listado de especies del género Pimeliaphilus Trägårdh asociadas a diferentes especies de triatominos, con sus respectivas coordenadas geográficas de todo el continente americano. Se realizaron viajes de campo para incorporar nuevos registros a una recopilación bibliográfica. Se extiende la distribución geográfica de Pimeliaphilus triatomae Cunliffe, con dos registros para la provincia de Chaco (Argentina y se amplía el rango de hospedadores ya que se citan por primera vez asociados a Triatoma delpontei Romaña & Abalos.

  10. Identificação e caracterização de peptídeos antimicrobianos da hemolinfa de Triatoma infestans (Hemiptera: Reduviidae).

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    Laura Cristina Lima Diniz

    2016-01-01

    Em Triatoma infestans ainda não há pesquisas de isolamento de Peptídeos Antimicrobianas e como têm contato muitos microrganismos acreditamos que eles produzem esses componentes antimicrobianos. Neste estudo identificamos quatro peptídeos antimicrobianos principais. Os Tin-TK-I e Tin-TK-II que são similares com Taquicininas de insetos, não são hemolíticos e ativos contra três bactérias e três fungos, e são capazes de lisar membranas. Tin-TK-I é degradado por aminopeptidases e tem estrutura r...

  11. Domestic Rhodnius ecuadoriensis (Hemiptera, Reduviidae) infestation in Northern Peru: a comparative trial of detection methods during a six-month follow-up.

    Science.gov (United States)

    Cuba Cuba, César Augusto; Vargas, Franklin; Roldan, Judith; Ampuero, Cynthia

    2003-01-01

    Two passive methods in the assessment of intradomiciliary infestation by Rhodnius ecuadoriensis were tested: (i) the Gomes Nu ez sensor box (GN), (ii) sheets of white typing paper and (iii) one active timed manual method. The study was carried out in the Alto Chicama River Valley, Province of Gran Chim , Department of La Libertad. The study design consisted of an initial searching of triatomines inside of the domestic environment by the manual capture active procedure (man/hour) covering all the studied houses. Then, matched pairs of GN boxes and paper sheets were simultaneously installed in the bedrooms of 207 households distributed in 19 localities. A comparative prospective trial of these passive detection devices were monitored at 2, 4 and, finally 6 months follow-up. Parasitological Trypanosoma rangeli and/or T. cruzi infections were investigated in two houses with high level of infestation by R. ecuadoriensis. 16.9% of the 207 households investigated by an initial active manual method were infested with R. ecuadoriensis. The proportion of infested houses fluctuated from 6.2 to 55.5% amongst the 19 localities investigated. T. rangeli natural infection was detected in R. ecuadoriensis specimens collected in two households. Parasite rates in the bugs ranged from 16.6 to 21.7% respectively. The most striking fact was an average rate of salivary gland infection ranging from 7.4 to 8.3%. At the end of the sixth month period, a cumulative incidence of 31.4% of positive GN boxes against 15.9% for paper sheets was recorded. All three methods combined detected domestic infestation in 129 (62.3%) of the 207 houses studied in the 19 localities. The range of houses infested varies from 6.7% to 92.9%. In areas with low bug density infestation rates, the methodology experienced in our studies, seems to be the best choice for investigations on domestic R. ecuadoriensis populations.

  12. Biologia do Triatoma nitida Usinger, 1939 em laboratório (Hemiptera: Reduviidae Biology of Triatoma nitida usinger, 1939 under laboratory coditions

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    Cleber Galvão

    1995-10-01

    Full Text Available Triatoma nitida is a wild species occurring in Mexico and Central America. In order to establish the length of its life cycle and transmission potential, the following parameters were observed: the incubation period, the interval between hatching, or moulting, and the first feeding; the number of blood meals and the time of development. The time-lapse before the bite, the length of feeding and the interval between the end of the blood meal and defecation, as well as the site of defecation were also analyzed. Average length of the egg incubation period was 18.2 days. Time interval between the food source offering and the bite was less than 4 min in 60//of the analyzed cases, except in the fifth instar, where only 38//of the insects began feeding in less than 5 min. The blood-sucking period was long and rising until the fifth instar, decreasing in adults, and ranging from 1 min to 2 and a half hours. Only 26//of the blood meals were followed by defecations within 20 min. The average length of the life cycle was 897.5 days.

  13. A genitália externa dos machos no complexo Triatoma phyllosoma (Burm. espécies mexicanas transmissoras da doença de Chagas (Hemiptera, Reduviidae

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    Herman Lent

    1982-09-01

    Full Text Available Foram estudadas as genitálias externas masculinas das cinco espécies que constituem o complexo phyllosoma: Triatoma phyllosoma (Burmeister, 1835, T. pallidipennis (Stal, 1872, T. longipennis Usinger, 1939, T. picturata Usinger, 1939 e T. mazzottii Usinger, 1941, todas encontradas naturalmente infectadas pelo Trypanosoma cruzi, e, com exceção de T. picturata, colonizando no domicílio humano. São espécies muito próximas, não só pelo aspecto externo, como pela área geográfica onde ocorrem, a região ocidental do México. As estruturas constituintes dessas genitálias foram analisadas comparativamente, com o intuito de ampliar o estudo das aludidas espécies, criando informações morfológicas adicionais à taxonomia atualmente aceita. Foram evidenciadas quatro estruturas no edeago: falosoma, suporte da falosoma, processo do endosoma e vesica; uma no aparelho articular, o processo do gonoporo; e outra no pigóforo, o processo do pigóforo. Essas estruturas apresentam pequenas variações no tamanho e na forma, acentuando a proximidade das espécies entre si e a dificuldade existente para a compreensão perfeita do status taxonômico de cada uma. O trabalho completar-se-á com a discussão dos já conhecidos aspectos morfológicos externos e os evidenciados pela morfologia das genitálias.A study was made of the male genitalia of five species which constitute the phyllosoma complex: Triatoma phyllosoma (Burmeister, 1835, T. pallidipennis (Stal, 1872, T. longipennis Usinger, 1939, T. picturata Usinger, 1939 and T. mazzottii Usinger, 1941; all of them were found naturally infected by Trypanosoma cruzi, and, except T. picturata colonizing human houses. These species are very similar, not only by the external aspects but also by their geographical occurence in Mexico. The structures which constitute these genitalias were analysed comparatively with the intention to increase the knowledge of the mentioned species, showing some morphological informations to the modern taxonomy. There were identified four aedeagus structures: phallosoma, struts, endosoma and vesica processes; one on articulatory apparatus, the gonopore process; and other on pygophore, the pygophore process. These structures show small variations in size and shape, emphasizing the relatioship between the species and the dificulty to the perfect understanding of the taxonomic status of each one.

  14. Entomological Indices, Feeding Sources, and Molecular Identification of Triatoma phyllosoma (Hemiptera: Reduviidae) One of the Main Vectors of Chagas Disease in the Istmo de Tehuantepec, Oaxaca, Mexico

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    Villalobos, Guiehdani; Martínez-Hernández, Fernando; de la Torre, Patricia; Laclette, Juan Pedro; Espinoza, Bertha

    2011-01-01

    The purpose of this study was to conduct an entomological analysis, determination of feeding sources, and molecular identification of triatomines in five communities of the Istmo de Tehuantepec, Oaxaca. The only found species in two of five searched communities (San Mateo del Mar and Tehuantepec City) was Triatoma phyllosoma. Colonization indices were high in both communities. In San Mateo del Mar, the insects were found indoors and in Tehuantepec City in peridomestic areas. The Trypanosoma cruzi infection indices were 2.1% in San Mateo del Mar and 39.4% in Tehuantepec City. This difference could be related to the high numbers of triatomine feeding on hens in the former community. In contrast, in Tehuantepec, dogs were the principal triatomine feeding sources. All nymphs and adults that were genetically analyzed belonged to the species T. phyllosoma. Low levels of genetic variation were found between vectors from both communities. PMID:21896810

  15. Survival and immune response of the Chagas vector Meccus pallidipennis (Hemiptera: Reduviidae) against two entomopathogenic fungi, Metarhizium anisopliae and Isaria fumosorosea.

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    Flores-Villegas, A Laura; Cabrera-Bravo, Margarita; Toriello, Conchita; Bucio-Torres, Martha I; Salazar-Schettino, Paz María; Córdoba-Aguilar, Alex

    2016-03-24

    Chagas disease is a key health problem in Latin America and is caused and transmitted by Trypanosoma cruzi and triatomine bugs, respectively. Control of triatomines has largely relied on the use pyrethroids, which has proved to be ineffective in the long term. Alternatively, the use of entomopathogenic fungi has been implemented to control triatomine bugs. These fungi are highly efficient as they induce a reduction in immune response on insects. Meccus pallidipennis is the main triatomine vector of Chagas disease in Mexico. In this work we investigated the effects of two entomopathogenic fungi, Metarhizium anisopliae and Isaria fumosorosea, on M. pallidipennis nymphs in terms of insect survival and immune response. We had an infected and a control group for each fungal species and assessed: a) insect survival during 30 days; and, b) phenoloxidase (PO) and prophenoloxidase (proPO; two key traits in insect immune response) at 24, 48, 96 and 144 h. For survival we used Kaplan-Meier survival analysis while for immune response we used factorial, repeated-measures ANOVA for each fungal species. Animals treated with M. anisopliae died sooner than animals treated with I. fumosorosea. Infected animals showed lower PO and proPO values than sham individuals, with a clear decrease in these parameters at 24 h with no further changes after this time. Our study widens the possibility of entomopathogenic fungi being used for triatomine control. The negative effect on PO and proPO seems mediated by a down-regulation of the triatomine immune response.

  16. Functional Response of the Predators Alloeocranum biannulipes (Hemiptera: Reduviidae) and Teretrius nigrescens (Coleoptera: Histeridae) Feeding on Dinoderus porcellus (Coleoptera: Bostrichidae) Infesting Yam Chips.

    Science.gov (United States)

    Loko, Y L; Djagoun, A D; Dannon, E A; Datinon, B; Dansi, A; Thomas-Odjo, A A; Tamo, M

    2017-02-01

    The functional response and some predation parameters of the predators Alloeocranum biannulipes Montrouzier & Signoret (Hemiptera: Reduviidea) and Teretrius nigrescens Lewis (Coleoptera: Histeridae) were evaluated at five different densities of larvae and pupae of Dinoderus porcellus Lesne (Coleoptera: Bostrichidae) with the aim to understand their roles in the biological control of this major pest of stored yam chips. Experiments were performed in petri dishes at 25 ± 1 °C, 60 ± 10% RH, and a photoperiod of 12:12 (L:D) h in a controlled temperature room. Both predators showed Type II of functional response with respect to larvae, determined by a logistic regression model. However, T. nigrescens significantly killed more larvae of D. porcellus compared with A. biannulipes. This behavior, however, changed to a linear functional response (Type I), when pupae of D. porcellus were offered to both predators, possibly because of their immobility. In addition, there was no significant difference between T. nigrescens and A. biannulipes in terms of the killed pupae. Parameters of the Holling disc equation for both predators were estimated. Estimated handling time on larvae of D. porcellus for T. nigrescens and A. biannulipes was 0.254 and 0.677 h and the rate of searching efficiency was 0.289 and 0.348 h-1, respectively. Results indicated that T. nigrescens was a more suitable candidate for augmentative release for D. porcellus control than A. biannulipes. However, semifield studies are required to draw firm conclusions. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Dados sôbre a biologia do Triatoma arthurneivai no sudeste do Estado de São Paulo, Brasil (Hemiptera, Reduviidae

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    Oswaldo Paulo Forattini

    1968-12-01

    Full Text Available Assinala-se o encontro de focos naturais do Triatoma arthurneivai Lent e Martins, 1940, na localidade de Itupararanga, Município de Votorantim, no Estado de São Paulo. Os ecótopos apresentaram as mesmas características já assinaladas anteriormente em regiões vizinhas, ou sejam, as de espaços localizados entre lascas de pedras de «granito róseo». O triatomíneo apresentou-se associado com lagartos Tropidurus torquatus Wied. mas, no laboratório, mostrou acentuada avidez por sangue de camundongos albinos. Por outro lado, a infecção experimental com Trypanosoma cruzi (cêpa F-1 foi obtida com facilidade. Em vista dos dados coletados, os autores permitem-se tecer considerações sôbre a possibilidade desse hemíptero vir a desempenhar algum papel transmissor, na natureza.An area with natural foci of Triatoma arthurneivai Lent & Martins, 1940, is recorded at the place of Itupararanga in the county of Salto de Pirapora, São Paulo State, Brasil. These foci were represented by ecotopes placed between sliced stones, similar to the ones previously described in surrounding regions. An association with lizards Tropidurus torquatus Wied. it was suspected to be of feeding nature. Nevertheless the triatomids showed to eat quickly and intensively white mice, under laboratory conditions. Beside this, the experimental infection by Trypanosoma cruzi was easily obtained. These data led the authors to suspect that T. arthurneivai may play some transmission role in nature.

  18. Primeiro registro de Saica apicalis Osborn & Drake para o Brasil e Pseudosaica florida (Barber, com notas taxonômicas e chave para os gêneros de Saicinae do Brasil (Hemiptera, Reduviidae First records of Saica apicalis Osborn & Drake and Pseudosaica florida (Barber in Brazil, with taxonomical notes and key for the Saicinae genera of Brazil (Hemiptera, Reduviidae

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    Hélcio R. Gil-Santana

    2005-06-01

    Full Text Available Apresenta-se o primeiro registro de ocorrência de Saica apicalis Osborn & Drake, 1915 e de Pseudosaica florida (Barber, 1953 no Brasil. Notas taxonômicas sobre Saica Amyot & Serville, 1843 e Pseudosaica Blinn, 1990 são fornecidas.The first records of Saica apicalis Osborn & Drake, 1915 and Pseudosaica florida (Barber, 1953 for Brazil are presented. Taxonomical notes on Saica Amyot & Serville, 1843 and Pseudosaica Blinn, 1990 are given.

  19. Monitoramento da suscetibilidade de populações de Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae ao inseticida deltametrina, na região Centro-Oeste do Brasil Monitoring the susceptibility of Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae to deltamethrin insecticide, in Central-Western Brazil

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    Marcos Takashi Obara

    2011-04-01

    Full Text Available INTRODUÇÃO: Populações de Triatoma sordida Stål, 1859 foram investigadas quanto à suscetibilidade à deltametrina. MÉTODOS: Análise por meio de bioensaios por aplicação tópica em 11 populações de T. sordida procedentes dos Estados de Goiás, Mato Grosso e Mato Grosso do Sul. RESULTADOS: As estimativas de DL50 e RR50 demonstraram elevados níveis de suscetibilidade (DL50 INTRODUCTION: Triatoma sordida Stål, 1859 populations were investigated for susceptibility to deltamethrin. METHODS: This study aimed to analyze the resistance of 11 populations of insects from the States of Goiás, Mato Grosso and Mato Grosso do Sul by topical application bioassays. RESULTS: The estimated LD50 and RR50 showed high levels of susceptibility (LD50 < 1 and RR50 < 2. However, analysis of the slope of the dose response curve showed that the populations of insects in the towns of Firminópolis/GO, Posse/GO, Poxoréu/MT, Douradina/MS and Aparecida do Taboado/MS present great probability of evolving resistance and, thus, are more likely to tolerate treatment with deltamethrin. CONCLUSIONS: Small changes in susceptibility and low levels of resistance were detected, but the temporal changes of susceptibility should be continuously monitored to adequately guide the actions of vector-control of DC.

  20. Comparative study of the stridulatorium sulcus, buccula and rostrum of nymphs of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al and Triatoma williami Galvão et al (Hemiptera: Reduviidae)

    OpenAIRE

    Silva, Maria B A; Jurberg, José; Galvão, Cleber; Barbosa, Helene S

    2010-01-01

    Ultrastructural analysis of the ventral region of the head - rostrum, buccula and stridulatorium sulcus - of 1st, 3rd and 5th instars of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al, and Triatoma williami Galvão et al, are described in here. Morphological differences in the analyzed structures for all three Triatoma species studied were detected under scanning electron microscopy, allowing their grouping by their morphological similarities. Species-specific differences at...

  1. Evaluación de la actividad tóxica de los insecticidas piretroides deltametrina y lambdacihalotrina en dos poblaciones de campo de Rhodnius pallescens (Hemíptera: Reduviidae de Panamá

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    Lorenzo Cáceres

    2011-04-01

    Conclusiones. En ninfas de estadios I y V de ambas poblaciones de R. pallescens, se observó mediante los valores obtenidos de factor de resistencia que no existen ninguna diferencia significativa en el efecto tóxico de los insecticidas estudiados. Esto permite establecer que las dos cepas de R. pallescens son sensibles a los insecticidas deltametrina y lambdacihalotrina.

  2. Efecto tóxico de b-cipermetrina, deltametrina y fenitrotión en cepas de Triatoma dimidiata (Latreille, 1811 y Triatoma maculata (Erichson, 1848 (Hemiptera, Reduviidae

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    Marlene Reyes

    2007-01-01

    Conclusión. En ninfas de primer estadio de T. dimidiata y T. maculata los insecticidas piretroides fueron mas efectivos; en ninfas de quinto estadio de T. dimidiata la efectividad de los piretroides del organofosforado fue diferente con las DL50; las ninfas de este estadio requirieron dosis altas comparadas con las utilizadas para otros triatominos, lo cual sugiere una baja susceptibilidad. La DL99 para el organofosforado fue significativamente menor, lo que podría indicar una mayor efectividad en campo. Es importante realizar estudios de efectos sinergistas para mostrar el posible rol de mecanismos bioquímicos que determine su tolerancia a los piretroides, esto representa un nuevo reto para las campañas de control en los países andinos y centroamericanos donde esta especie es endémica.

  3. Monitoramento da suscetibilidade de populações de Triatoma sordida Stål, 1859 (Hemiptera: Reduviidae ao inseticida deltametrina, na região Centro-Oeste do Brasil

    Directory of Open Access Journals (Sweden)

    Marcos Takashi Obara

    2011-04-01

    Full Text Available INTRODUÇÃO: Populações de Triatoma sordida Stål, 1859 foram investigadas quanto à suscetibilidade à deltametrina. MÉTODOS: Análise por meio de bioensaios por aplicação tópica em 11 populações de T. sordida procedentes dos Estados de Goiás, Mato Grosso e Mato Grosso do Sul. RESULTADOS: As estimativas de DL50 e RR50 demonstraram elevados níveis de suscetibilidade (DL50 < 1 e RR50 < 2. Entretanto, as análises do coeficiente angular da curva dose resposta revelaram que as populações de triatomíneos dos municípios de Firminópolis/GO, Posse/GO, Poxoréu/MT, Douradina/MS e Aparecida do Taboado/MS apresentam maiores probabilidades de evolução de resistência, portanto, mais propícias a tolerar o tratamento com deltametrina. CONCLUSÕES: Detectaram-se pequenas alterações de suscetibilidade e baixos níveis de resistência, porém as alterações temporais de suscetibilidade deverão ser continuamente monitoradas, a fim de nortear adequadamente as ações de controle dos vetores da DC.

  4. Validation of reference genes for expression analysis in the salivary gland and the intestine of Rhodnius prolixus (Hemiptera, Reduviidae under different experimental conditions by quantitative real-time PCR

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    Paim Rafaela M

    2012-03-01

    Full Text Available Abstract Background Rhodnius prolixus is a blood-feeding insect that can transmit Trypanosoma cruzi and Trypanosoma rangeli to vertebrate hosts. Recently, genomic resources for invertebrate vectors of human pathogens have increased significantly, and R. prolixus has been one of the main species studied among the triatomines. However, the paucity of information on many of the fundamental molecular aspects of this species limits the use of the available genomic information. The present study aimed to facilitate gene expression studies by identifying the most suitable reference genes for the normalization of mRNA expression data from qPCR. Results The expression stability of five candidate reference genes (18S rRNA, GAPDH, β-actin, α-tubulin and ribosomal protein L26 was evaluated by qPCR in two tissues (salivary gland and intestine and under different physiological conditions: before and after blood feeding and after infection with T. cruzi or T. rangeli. The results were analyzed with three software programs: geNorm, NormFinder and BestKeeper. All of the evaluated candidate genes proved to be acceptable as reference genes, but some were found to be more appropriate depending on the experimental conditions. 18S, GAPDH and α-tubulin showed acceptable stability for studies in all of the tissues and experimental conditions evaluated. β-actin, one of the most widely used reference genes, was confirmed to be one of the most suitable reference genes in studies with salivary glands, but it had the lowest expression stability in the intestine after insect blood feeding. L26 was identified as the poorest reference gene in the studies performed. Conclusions The expression stability of the genes varies in different tissue samples and under different experimental conditions. The results provided by three statistical packages emphasize the suitability of all five of the tested reference genes in both the crop and the salivary glands with a few exceptions. The results emphasise the importance of validating reference genes for qRT-PCR analysis in R. prolixus studies.

  5. The Role of DmCatD, a Cathepsin D-Like Peptidase, and Acid Phosphatase in the Process of Follicular Atresia in Dipetalogaster maxima (Hemiptera: Reduviidae), a Vector of Chagas' Disease

    Science.gov (United States)

    Leyria, Jimena; Fruttero, Leonardo L.; Nazar, Magalí; Canavoso, Lilián E.

    2015-01-01

    In this work, we have investigated the involvement of DmCatD, a cathepsin D-like peptidase, and acid phosphatase in the process of follicular atresia of Dipetalogaster maxima, a hematophagous insect vector of Chagas’ disease. For the studies, fat bodies, ovaries and hemolymph were sampled from anautogenous females at representative days of the reproductive cycle: pre-vitellogenesis, vitellogenesis as well as early and late atresia. Real time PCR (qPCR) and western blot assays showed that DmCatD was expressed in fat bodies and ovaries at all reproductive stages, being the expression of its active form significantly higher at the atretic stages. In hemolymph samples, only the immunoreactive band compatible with pro-DmCatD was observed by western blot. Acid phosphatase activity in ovarian tissues significantly increased during follicular atresia in comparison to pre-vitellogenesis and vitellogenesis. A further enzyme characterization with inhibitors showed that the high levels of acid phosphatase activity in atretic ovaries corresponded mainly to a tyrosine phosphatase. Immunofluorescence assays demonstrated that DmCatD and tyrosine phosphatase were associated with yolk bodies in vitellogenic follicles, while in atretic stages they displayed a different cellular distribution. DmCatD and tyrosine phosphatase partially co-localized with vitellin. Moreover, their interaction was supported by FRET analysis. In vitro assays using homogenates of atretic ovaries as the enzyme source and enzyme inhibitors demonstrated that DmCatD, together with a tyrosine phosphatase, were necessary to promote the degradation of vitellin. Taken together, the results strongly suggested that both acid hydrolases play a central role in early vitellin proteolysis during the process of follicular atresia. PMID:26091289

  6. The genus Zelurus Hahn, 1826, in Brazilian caves: description of new species and comments on the potential distribution of the genus in South America.

    Science.gov (United States)

    Ferreira, Marina Izabel Grave; Ferreira, Rodrigo Lopes; Gil-Santana, Hélcio R

    2016-09-23

    A survey on species of the genus Zelurus Hahn, 1826 (Reduviidae) occurring in Brazilian caves is provided. Zelurus tambejua sp. n. and Zelurus gerevatinga sp. n. collected from caves in Brazil are described. Comments about the current and potential distribution of the genus as a whole and of species of Zelurus found in caves for South America are also provided.

  7. Author Details

    African Journals Online (AJOL)

    Sahayaraj, K. Vol 10 (2008) - Articles Ecology of Dysdercus cingulatus morphs. Abstract · Vol 9 (2007) - Articles Ecotypic variation in the biology of Acanthaspis quinquespinosa Fabricius 1781 (Hemiptera: Reduviidae: Reduviinae) from peninsular India Abstract PDF. ISSN: 1110-6859. AJOL African Journals Online.

  8. The Stenopodainae (Hemiptera, Heteroptera) of Argentina

    Science.gov (United States)

    Diez, Fernando; Coscarón, María del Carmen

    2014-01-01

    Abstract In Argentina, 10 genera and 33 species of Stenopodainae (Hemiptera: Reduviidae) have been recorded. Diagnoses of the genera, subgenera and species are given, and an illustrated key to genera is provided. Six species are new records for Argentina and an additional seven species represent new records for provinces. PMID:25493054

  9. A DNA investigation into the mysterious disappearance of the Rocky Mountain grasshopper, mega-pest of the 1800s.

    Science.gov (United States)

    Chapco, W; Litzenberger, G

    2004-03-01

    The mysterious extinction of the Rocky Mountain Grasshopper, Melanoplus spretus, a major pest species on the prairies and plains of the 1800s, is truly a remarkable event in the history of agriculture. Recently, we obtained specimens of M. spretus from museums and from 400-year-old glacial deposits in Wyoming. We report success in obtaining mitochondrial DNA sequences from both sources. This permitted us to examine two issues surrounding the species' disappearance. First, a long-standing view that M. spretus and the extant species Melanoplus sanguinipes are (if not phase transforms of one another) sister taxa, is disputed, but cannot be rejected with certainty. Interestingly, there is some evidence that suggests there may be a closer affinity with another member of the Mexicanus species-group, Melanoplus bruneri. Second, because M. spretus still possesses considerable nucleotide diversity (1.15+/-0.19%), a depletion of variation cannot be considered a factor contributing to its demise.

  10. Influence of weather variables and plant communities on grasshopper density in the Southern Pampas, Argentina.

    Science.gov (United States)

    de Wysiecki, María Laura; Arturi, Marcelo; Torrusio, Sandra; Cigliano, María Marta

    2011-01-01

    A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996-2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and

  11. Análise das relações taxonômicas e sistemáticas entre espécies de triatomíneos (Hemiptera, Reduviidae de colônias mantidas pelo Serviço Especial de Saúde de Araraquara, inferida de seqüências do 16S rDNA mitocondrial Taxonomic and systematic analysis among triatomine bug species (Hemiptera, Reduviidae from colonies of the Special Health Service of Araraquara (SESA, inferred from 16S rDNA mitocondrial sequences

    Directory of Open Access Journals (Sweden)

    Walter Ceretti Junior

    2008-09-01

    Full Text Available Foram analisadas seqüências de nucleotídeos do gene 16S do rDNA mitocondrial em 14 populações de triatomíneos mantidos em colônias no insetário SESA de Araraquara- SP, comparando-as com seqüências do mesmo gene disponíveis no GenBank. Os fragmentos variaram de 311 a 317 pb com baixa variação intra-específica entre as distâncias genéticas (0% a 0,6%, exceto para os relacionamentos entre espécimes de Triatoma sordida (1% e espécimes de T. brasiliensis (1,3% atribuídos a populações geográficas diferentes. A parafilia de Rhodniini e do gênero Panstrongylus foi evidenciada pelas analises, confirmando resultados anteriores entre estes e os estreitos relacionamentos de R. prolixus com R. robustus e de T. infestans e T. platensis. O relacionamento entre T. maculata e T. pseudomaculata não foi solucionado, uma vez que, esses táxons apareceram tanto em monofilia quanto em parafilia: T. pseudomaculata (SESA está agrupado com T. maculata (seqüência do GenBank e associados a T . brasiliensis (SESA, enquanto T. maculata (SESA aparece agrupado com T. pseudomaculata do SESA e do GenBank. Os resultados evidenciam a utilidade do gene 16S como marcador de espécies de triatomíneos e sua importância em questões de sistemática e taxonomia. Há necessidade de novos estudos envolvendo outros marcadores associados a caracteres sistemáticos clássicos de morfologia, ecologia e comportamento para decisões sistemáticas adequadas uma vez, que teriam impacto não apenas sistemático mas, para as estratégias de controle.Nucleotide sequences of mitocondrial 16S rDNA gene were analyzed in 14 populations of triatomine bugs from colonies maintained by SESA, Araraquara, São Paulo, Brazil, comparing them with sequences of same gene found in the GenBank. The fragments varied from 311 to 317 bp, with low intra-specific genetic distance (0% to 0.6%, with exception of the relationship among Triatoma sordida specimens (1% and T. brasiliensis specimens (1.3% that were attributed to different geographical populations. The paraphily of Rhodniini and Panstrongylus genus was evidenced by this analyses, confirming previous results between these and the narrow relationships of R. prolixus with R. robustus and of T. infestans with T. platensis. The relationship between T. maculata and T. pseudomaculata has not been resolved, since these taxa appeared both in monophyly and as in paraphyly: T. pseudomaculata (SESA is grouped with T. maculata (sequence of GenBank and the associated T. brasiliensis (SESA, while T. maculata (SESA appears grouped with T. pseudomaculata of SESA and GenBank. The results evidence the utility of the gene 16S as molecular marker in the species of triatomine bugs and its importance in systematic and taxonomy questions. There is a necessity of new studies including new molecular markers associated with classic systematic characters of morphology, ecology and behavior to adjust systematic decisions since those will be not of only systematic impact but, for new strategies of control.

  12. Gene discovery in Triatoma infestans

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    de Burgos Nelia

    2011-03-01

    Full Text Available Abstract Background Triatoma infestans is the most relevant vector of Chagas disease in the southern cone of South America. Since its genome has not yet been studied, sequencing of Expressed Sequence Tags (ESTs is one of the most powerful tools for efficiently identifying large numbers of expressed genes in this insect vector. Results In this work, we generated 826 ESTs, resulting in an increase of 47% in the number of ESTs available for T. infestans. These ESTs were assembled in 471 unique sequences, 151 of which represent 136 new genes for the Reduviidae family. Conclusions Among the putative new genes for the Reduviidae family, we identified and described an interesting subset of genes involved in development and reproduction, which constitute potential targets for insecticide development.

  13. Descrição dos Ovos e dos Estádios Ninfais de Triatoma jurbergi Carcavallo, Galvão & Lent, 1998 Vistos Através de Microscopia Óptica e Eletrônica de Varredura (Hemiptera, Reduviidae Description of Eggs and Nymphs of Triatoma jurbergi Carcavallo, Galvão & Lent, 1998 Through Optical and Scanning Electron Microscopy

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    José Jurberg

    2002-03-01

    Full Text Available Eggs and nymphs of Triatoma jurbergi were described using optical microscopy and scanning electron microscopy. T. jurbergi is a wild species, found in State of Mato Grosso (15ºS and 300 m.a.s.l, Brazil. Eggs showed the operculum and surface with pentagonal and hexagonal cells, with small fractures and punctuations randomly distributed. Differences were found in the five nymphal stages of T. jurbergi, that allow their to be distinguished from the similar species T. guazu. The diagnostic characters most useful for differentiation were the general color of the insect, abdomen shape and its length.

  14. Observações sobre oviposição, eclosão e tempo de vida de Triatoma matogrossensis Leite & Barbosa, 1953 (Hemiptera-Reduviidae em função da alimentação em pombos e coelhos

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    Marassá Ana Maria

    1998-01-01

    Full Text Available Estudou-se em laboratório a influência de duas diferentes fontes de alimentação sobre oviposição, eclosão dos ovos e tempo de vida de casais de Triatoma matogrossensis. Foram observados 68 casais separados em quatro diferentes grupos, com 20, 12, 20 e 16 casais, respectivamente. Os grupos A1 e A 2 foram alimentados em pombos e os grupos C1 e C 2 em coelhos. Os casais foram mantidos em estufa a 26o ± 2oC e UR de 60-80%, com fotoperíodo de 14 horas. O maior número de ovos postos foi encontrado no grupo A1. Não houve diferença na proporção de ovos eclodidos dos grupos alimentados em coelhos ou pombos. Não foram observadas diferenças de tempo de vida entre machos e fêmeas dos quatro grupos, entretanto o grupo A1 apresentou o maior tempo de sobrevivência e o grupo C2 o menor.

  15. Fonte alimentar e potencial vetorial de Triatoma vitticeps (Stal, 1859 com relação à doença de Chagas humana no estado do Espírito Santo, Brasil (Hemiptera, Reduviidae Feeding and vectorial capacity of Triatoma vitticeps (Stal, 1859 in relation with human chagas' disease in Espírito Santo State, Brazil

    Directory of Open Access Journals (Sweden)

    João Carlos Pinto Dias

    1989-01-01

    Full Text Available In paralel with several other epidemiologic and entomologic data of 19 Municipalities of Espírito Santo State, Brazil, the feeding pattern of 222 Triatoma vitticeps is studied through precipitin tests. Very high levels of natural infection with Trypanosoma cruzi are observed in adult insects, in contrast with the abscence or minimum degrees of infection among nymphs and human individuals. The precipitin tests showed the contact of the insects with multiple blood sources, chiefly human and birds, followed by rodents and marsupials. The data suggest that T. vitticeps in spite of being highly antropophilic, become infected by T. cruzi in sylvatic ambient and occasionally invade houses. The species doesn't seem to be - at least until now - a good vector in the domestic cycle of Chagas' disease. Several factors seem to be involved in this conclusion, mainly the low density of the insect in the houses, its hardness to coloniza them, its slowness concerning to suction and defecation and possibly its low susceptibility to different T. cruzi strains.

  16. Novel adipokinetic hormones in the kissing bugs Rhodnius prolixus, Triatoma infestans, Dipetalogaster maxima and Panstrongylus megistrus

    Czech Academy of Sciences Publication Activity Database

    Marco, H. G.; Šimek, Petr; Clark, K. D.; Gäde, G.

    2013-01-01

    Roč. 41, MAR 10 (2013), s. 21-30 ISSN 0196-9781 R&D Projects: GA MZd(CZ) NT11513 Grant - others:National Research Foundation(ZA) IFR 2008071500048; National Research Foundation(ZA) FA 2007021300002 Institutional support: RVO:60077344 Keywords : insects * kissing bugs * reduviidae Subject RIV: ED - Physiology Impact factor: 2.614, year: 2013 http://www.sciencedirect.com/science/article/pii/S0196978112004433

  17. Ticks, ivermectin, and experimental Chagas disease

    Directory of Open Access Journals (Sweden)

    João Carlos Pinto Dias

    2005-12-01

    Full Text Available Following an infestation of dogticks in kennels housing dogs used for long-term studies of the pathogenesis of Chagas disease, we examined the effect of ivermectin treatment on the dogs, ticks, trypanosome parasites, and also on triatomine vectors of Chagas disease. Ivermectin treatment was highly effective in eliminating the ticks, but showed no apparent effect on the dogs nor on their trypanosome infection. Triatominae fed on the dogs soon after ivermectin treatment showed high mortality, but this effect quickly declined for bugs fed at successive intervals after treatment. In conclusion, although ivermectin treatment may have a transient effect on peridomestic populations of Triatominae, it is not the treatment of choice for this situation. The study also showed that although the dogticks could become infected with Trypanosoma cruzi, this only occurred when feeding on dogs in the acute phase of infection, and there was no evidence of subsequent parasite development in the ticks.

  18. Active transmission of human chagas disease in Colima Mexico

    OpenAIRE

    Coll-Cárdenas, Rafael; Espinoza-Gómez, Francisco; Maldonado-Rodríguez, Arcadio; Reyes-López, Pedro A; Huerta-Viera, Miguel; Rojas-Larios, Fabián

    2004-01-01

    Despite efforts to eradicate American trypanosomiasis (AT) and Chagas disease from the Americas, there are still areas of active transmission that can eventually become a source of reinfection in previously controlled regions. Mexico could be one of those areas, where there are no formal preventive control programs despite the presence of communities infested by Triatominae bugs infected with Trypanosoma cruzi. This study explored the prevalence of T. cruzi infection in 405 habitants of 17 co...

  19. Donnees Preliminaires Sur l'entomofaune de Lippia multiflora Mold ...

    African Journals Online (AJOL)

    En outre, elles sont parfois minées par une espèce d'abeille et une espèce de guêpe qui y accomplissent leur cycle de développement. Comme insectes utiles, des mantes religieuses et une espèce de Reduviidae ont été recensées. Un Hyménoptère parasitoïde de la famille des Pteromalidae, a émergé à partir des galles ...

  20. Molecular Techniques for Dicistrovirus Detection without RNA Extraction or Purification

    Directory of Open Access Journals (Sweden)

    Jailson F. B. Querido

    2013-01-01

    Full Text Available Dicistroviridae is a new family of small, nonenveloped, and +ssRNA viruses pathogenic to both beneficial arthropods and insect pests as well. Triatoma virus (TrV, a dicistrovirus, is a pathogen of Triatoma infestans (Hemiptera: Reduviidae, one of the main vectors of Chagas disease. In this work, we report a single-step method to identify TrV, a dicistrovirus, isolated from fecal samples of triatomines. The identification method proved to be quite sensitive, even without the extraction and purification of RNA virus.

  1. Types of true bugs (Insecta, Hemiptera, Heteroptera) deposited in the Museo de La Plata, Argentina.

    Science.gov (United States)

    Coscarón, María Del Carmen; Basset, Carina; Lopez, Nancy

    2015-06-25

    A checklist of Heteroptera type specimens deposited in the collection of División Entomología, Museo de La Plata. It harbours type material of 1153 species belonging to 37 families (Enicocephalidae, Schizopteridae, Gerridae, Veliidae, Hydrometridae, Naucoridae, Belostomatidae, Nepidae, Corixidae, Notonectidae, Pleidae, Saldidae, Cimicidae, Polyctenidae, Nabidae, Miridae, Tingidae, Vianaididae, Thaumastocoridae, Reduviidae, Aradidae, Alydidae, Coreidae, Rhopalidae, Berytidae, Blissidae, Lygaeidae, Oxycarenidae, Rhyparochromidae, Idiostolidae, Largidae, Pyrrhocoridae, Anthocoridae, Cydnidae, Pentatomidae, Scutelleridae, Thyreocoridae), represented by 207 holotypes, 26 allotypes, 578 paratypes, 1 lectotype, 1 paralectotype and 340 syntypes. For each taxon providing update information on valid names, categories of types, and locality.

  2. An update of the types of Heteroptera (Hemiptera) housed at the Museo de La Plata Entomological Collection (Argentina).

    Science.gov (United States)

    Montemayor, Sara Itzel; Dellapé, Pablo Matías

    2013-01-08

    We present a list of the type material of Heteroptera deposited in the entomological collection of the Museo de La Plata (Buenos Aires, Argentina) in the last six years and or, not included in previous catalogs. This catalog includes 244 specimens belonging to 43 holotypes, one neotype, and 200 paratypes. The type material examined belongs to 50 species from 43 genera distributed in 16 families: Schizopteridae, Hydrometridae, Naucoridae, Thaumastocoridae, Miridae, Tingidae, Vianaididae, Reduviidae, Alydidae, Rhopalidae, Largidae , Berytidae, Blissidae, Lygaeidae, Oxycarenidae, and Rhyparochromidae.

  3. Aportes al conocimiento de los cromosomas holocíneticos de Hemiptera: estudios citogenéticos y evolutivos en especies de Cimicomorpha

    OpenAIRE

    Poggio, María Georgina

    2012-01-01

    El presente trabajo de Tesis Doctoral se basa en el estudio citogenético clásico, molecular y evolutivo de especies de insectos hematófagos y predadores pertenecientes a las familias Cimicidae y Reduviidae del infraorden Cimicomorpha (Hemiptera: Heteroptera), que se caracterizan por presentar cromosomas holocinéticos. Se analizó el complemento cromosómico, el desarrollo meiótico masculino, el contenido, distribución y composición de la heterocromatina y el número y la localización de los gene...

  4. Do Bites of Kissing Bugs Cause Unexplained Allergies? Results from a Survey in Triatomine-Exposed and Unexposed Areas in Southern California

    Science.gov (United States)

    Walter, Jan; Fletcher, Erin; Moussaoui, Roba; Gandhi, Kumar; Weirauch, Christiane

    2012-01-01

    Background The bite of Triatominae can cause cutaneous allergic reactions and even anaphylaxis. Since the early 1980s, no population-based surveys have been done in Southern California, and none was ever carried out in inland Los Angeles or Riverside Counties. Objectives To measure the frequency of insect sightings, bites and allergic reactions in a suburban area of eastern Los Angeles County and along with rural and urban sites in Riverside County. Methods A door-to-door survey was done in triatomine exposed and unexposed areas. Logistic regression modeling was used for the analysis, and study participants were asked to collect insects. Results Out of the 221 study participants in the exposed areas, 46 (20%) knew about the presence of Triatominae in their neighborhood. Fifteen (7%) persons reported triatomine sightings in their house during the month preceding the interview. Also, 15 (7%) participants reported ever being bitten by a triatomine. Ten (5%) participants collected either a Triatoma protracta Uhler and/or Paratriatoma hirsuta Barber in and around their house. Twenty-nine (13%) persons in the rural Riverside County reported symptoms compatible with allergy to triatomine bites. This was 4 times higher than in the urban control area where only 4 (3%) of 115 persons reported these symptoms. The association between living in a triatomine-exposed area and self-reported symptoms suggestive of allergies increased slightly when adjusted for the participant’s sex and the age of their house (adjusted odds ratio: 5.1, 95% confidence interval: 1.2 to 22.0). Reporting these symptoms was associated with seeing Triatominae in the neighborhood and having been bitten. Conclusion Allergies to triatomine bites could be a significant problem in inland Southern California. Further investigations, a diagnostic test and better information of persons living in triatomine-exposed areas are needed. PMID:22937146

  5. A mathematical model of Chagas disease transmission

    Science.gov (United States)

    Hidayat, Dayat; Nugraha, Edwin Setiawan; Nuraini, Nuning

    2018-03-01

    Chagas disease is a parasitic infection caused by protozoan Trypanosoma cruzi which is transmitted to human by insects of the subfamily Triatominae, including Rhodnius prolixus. This disease is a major problem in several countries of Latin America. A mathematical model of Chagas disease with separate vector reservoir and a neighboring human resident is constructed. The basic reproductive ratio is obtained and stability analysis of the equilibria is shown. We also performed sensitivity populations dynamics of infected humans and infected insects based on migration rate, carrying capacity, and infection rate parameters. Our findings showed that the dynamics of the infected human and insect is mostly affected by carrying capacity insect in the settlement.

  6. Abundance of Mepraia spinolai in a Periurban zone of Chile.

    Science.gov (United States)

    Cattan, Pedro E; Pinochet, Angélica; Botto-Mahan, Carezza; Acuna, Mariana I; Canals, Mauricio

    2002-04-01

    Mepraia spinolai is a silvatic species of Triatominae which prefers microhabitats near to or in rock piles. It is also able to maintain similar or higher size populations near houses. The density of bugs in quarries near Santiago, Chile, differed within microhabitats and varied significantly within sites according to season. M. spinolai was not found in sites characterized by human perturbation of quarries. Our results confirm M. spinolai as a silvatic triatomine whose importance as a vector of Chagas disease will depend on contact with humans. This could occur if the habitats where populations of this species are found become exploited for the building of urban areas.

  7. Abundance of Mepraia spinolai in a Periurban Zone of Chile

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    Cattan Pedro E

    2002-01-01

    Full Text Available Mepraia spinolai is a silvatic species of Triatominae which prefers microhabitats near to or in rock piles. It is also able to maintain similar or higher size populations near houses. The density of bugs in quarries near Santiago, Chile, differed within microhabitats and varied significantly within sites according to season. M. spinolai was not found in sites characterized by human perturbation of quarries. Our results confirm M. spinolai as a silvatic triatomine whose importance as a vector of Chagas disease will depend on contact with humans. This could occur if the habitats where populations of this species are found become exploited for the building of urban areas.

  8. Microbial symbiosis and the control of vector-borne pathogens in tsetse flies, human lice, and triatomine bugs

    Science.gov (United States)

    Sassera, Davide; Epis, Sara; Pajoro, Massimo; Bandi, Claudio

    2013-01-01

    Symbiosis is a widespread biological phenomenon, and is particularly common in arthropods. Bloodsucking insects are among the organisms that rely on beneficial bacterial symbionts to complement their unbalanced diet. This review is focused on describing symbiosis, and possible strategies for the symbiont-based control of insects and insect-borne diseases, in three bloodsucking insects of medical importance: the flies of the genus Glossina, the lice of the genus Pediculus, and triatomine bugs of the subfamily Triatominae. Glossina flies are vector of Trypanosoma brucei, the causative agent of sleeping sickness and other pathologies. They are also associated with two distinct bacterial symbionts, the primary symbiont Wigglesworthia spp., and the secondary, culturable symbiont Sodalis glossinidius. The primary symbiont of human lice, Riesia pediculicola, has been shown to be fundamental for the host, due to its capacity to synthesize B-group vitamins. An antisymbiotic approach, with antibiotic treatment targeted on the lice symbionts, could represent an alternative strategy to control these ectoparasites. In the case of triatominae bugs, the genetic modification of their symbiotic Rhodococcus bacteria, for production of anti-Trypanosoma molecules, is an example of paratransgenesis, i.e. the use of symbiotic microorganism engineered in order to reduce the vector competence of the insect host. PMID:24188239

  9. [Diversity and distribution of grasshoppers (Orthoptera: Acridoidea) in grasslands of the Southern Pampas region, Argentina].

    Science.gov (United States)

    Mariottini, Yanina; De Wysiecki, María Laura; Lange, Carlos Ernesto

    2013-03-01

    abundance and distribution. Covasacris pallidinota, Dichroplus elongatus, D. maculipennis, Borellia bruneri and B. pallida were the most widely distributed species, most of them (12) showed a restricted distribution and few (five) an intermediate distribution.

  10. Population differentiation of the Chagas disease vector Triatoma maculata (Erichson, 1848) from Colombia and Venezuela.

    Science.gov (United States)

    Monsalve, Yoman; Panzera, Francisco; Herrera, Leidi; Triana-Chávez, Omar; Gómez-Palacio, Andrés

    2016-06-01

    The emerging vector of Chagas disease, Triatoma maculata (Hemiptera, Reduviidae), is one of the most widely distributed Triatoma species in northern South America. Despite its increasing relevance as a vector, no consistent picture of the magnitude of genetic and phenetic diversity has yet been developed. Here, several populations of T. maculata from eleven Colombia and Venezuela localities were analyzed based on the morphometry of wings and the mitochondrial NADH dehydrogenase subunit 4 (ND4) gene sequences. Our results showed clear morphometric and genetic differences among Colombian and Venezuelan populations, indicating high intraspecific diversity. Inter-population divergence is suggested related to East Cordillera in Colombia. Analyses of other populations from Colombia, Venezuela, and Brazil from distinct eco-geographic regions are still needed to understand its systematics and phylogeography as well as its actual role as a vector of Chagas disease. © 2016 The Society for Vector Ecology.

  11. Architectural diversity and galling insects on Caryocar brasiliense trees.

    Science.gov (United States)

    Leite, Germano Leão Demolin; Veloso, Ronnie Von Dos Santos; Zanuncio, José Cola; Azevedo, Alcinei Mistico; Silva, Júlia Letícia; Wilcken, Carlos Frederico; Soares, Marcus Alvarenga

    2017-11-30

    Galling insects are a highly sophisticated herbivore group on Caryocar brasiliense, a tree that represents the main income source for many communities. The effect of architectural diversity of C. brasiliense trees on galling insect community diversity and abundance was studied. The abundance of adult insects and galled leaves were seven and 1.6 times higher in trees with a greater height/width of canopy (RHW) ratio, respectively. Gall parasitoid richness was 1.8 times greater on trees with higher RHW. Zelus armillatus (Lepeletier & Serville) (Hemiptera: Reduviidae) and ant numbers were 5.8 and 2.7 higher on trees with the largest and smallest RHW, respectively. More complex plant architectures favored species diversity for galling insects and their natural enemies. The competition among four galling insect species for space and feeding and the evidence of "prudence strategy" were, for the first time, observed for galling insects in the Brazilian Cerrado biome.

  12. Ultrastructure of the midgut in Heteroptera (Hemiptera) with different feeding habits.

    Science.gov (United States)

    Santos, Helen Pinto; Rost-Roszkowska, Magdalena; Vilimova, Jitka; Serrão, José Eduardo

    2017-07-01

    Heteroptera have diverse feeding habits with phytophagous, zoophagous, and haematophagous species. This dietary diversity associated with the monophyly of Heteroptera makes these insects a good object for comparative studies of the digestive tract. This work compares the ultrastructure of the middle midgut region in the phytophagous Coptosoma scutellatum (Plataspidae), Graphosoma lineatum (Pentatomidae), Kleidocerys resedae (Lygaeidae), and zoophagous Rhynocoris iracundus (Reduviidae), Nabis rugosus (Nabidae), and Himacerus apterus (Nabidae), to verify if diet affects midgut cells in phylogenetically related insects. The middle region of the midgut was used for comparison because it is the main site for digestion and absorption of the midgut. The digestive cell ultrastructure was similar in the six species, with features of secretory, absorptive, transport, storage, and excretory cells, suggesting a stronger correlation of middle digestive cell ultrastructure with the phylogeny of these species than with the different heteropteran feeding habits.

  13. Automated identification of insect vectors of Chagas disease in Brazil and Mexico: the Virtual Vector Lab

    Directory of Open Access Journals (Sweden)

    Rodrigo Gurgel-Gonçalves

    2017-04-01

    Full Text Available Identification of arthropods important in disease transmission is a crucial, yet difficult, task that can demand considerable training and experience. An important case in point is that of the 150+ species of Triatominae, vectors of Trypanosoma cruzi, causative agent of Chagas disease across the Americas. We present a fully automated system that is able to identify triatomine bugs from Mexico and Brazil with an accuracy consistently above 80%, and with considerable potential for further improvement. The system processes digital photographs from a photo apparatus into landmarks, and uses ratios of measurements among those landmarks, as well as (in a preliminary exploration two measurements that approximate aspects of coloration, as the basis for classification. This project has thus produced a working prototype that achieves reasonably robust correct identification rates, although many more developments can and will be added, and—more broadly—the project illustrates the value of multidisciplinary collaborations in resolving difficult and complex challenges.

  14. High-resolution melting (HRM of the cytochrome B gene: a powerful approach to identify blood-meal sources in Chagas disease Vectors.

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    Victor H Peña

    Full Text Available Methods to determine blood-meal sources of hematophagous Triatominae bugs (Chagas disease vectors are serological or based on PCR employing species-specific primers or heteroduplex analysis, but these are expensive, inaccurate, or problematic when the insect has fed on more than one species. To solve those problems, we developed a technique based on HRM analysis of the mitochondrial gene cytochrome B (Cyt b. This technique recognized 14 species involved in several ecoepidemiological cycles of the transmission of Trypanosoma cruzi and it was suitable with DNA extracted from intestinal content and feces 30 days after feeding, revealing a resolution power that can display mixed feedings. Field samples were analyzed showing blood meal sources corresponding to domestic, peridomiciliary and sylvatic cycles. The technique only requires a single pair of primers that amplify the Cyt b gene in vertebrates and no other standardization, making it quick, easy, relatively inexpensive, and highly accurate.

  15. High-Resolution Melting (HRM) of the Cytochrome B Gene: A Powerful Approach to Identify Blood-Meal Sources in Chagas Disease Vectors

    Science.gov (United States)

    Peña, Victor H.; Fernández, Geysson J.; Gómez-Palacio, Andrés M.; Mejía-Jaramillo, Ana M.; Cantillo, Omar; Triana-Chávez, Omar

    2012-01-01

    Methods to determine blood-meal sources of hematophagous Triatominae bugs (Chagas disease vectors) are serological or based on PCR employing species-specific primers or heteroduplex analysis, but these are expensive, inaccurate, or problematic when the insect has fed on more than one species. To solve those problems, we developed a technique based on HRM analysis of the mitochondrial gene cytochrome B (Cyt b). This technique recognized 14 species involved in several ecoepidemiological cycles of the transmission of Trypanosoma cruzi and it was suitable with DNA extracted from intestinal content and feces 30 days after feeding, revealing a resolution power that can display mixed feedings. Field samples were analyzed showing blood meal sources corresponding to domestic, peridomiciliary and sylvatic cycles. The technique only requires a single pair of primers that amplify the Cyt b gene in vertebrates and no other standardization, making it quick, easy, relatively inexpensive, and highly accurate. PMID:22389739

  16. Current situation of Chagas disease in Central America

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    Carlos Ponce

    2007-10-01

    Full Text Available Chagas disease in Central America is known since 1913 when the first human case was reported in El Salvador. The other Central American countries reported their first cases between 1933 and 1967. On October 1997 was launched the Central American Initiative for Chagas Disease Control (IPCA. The objectives of this sub-regional Initiative are: (1 the elimination of Rhodnius prolixus in Central America; (2 the reduction of the domiciliary infestation of Triatoma dimidiata; and (3 the elimination of the transfusion transmission of Trypanosoma cruzi. Significant advancements being close to the elimination of R. prolixus in Central America and the control of the transfusion transmission has been a transcendent achievement for the sub-region. The main challenges that the IPCA will have in the close future are: developing effective strategies for control and surveillance of T. dimidiata; and surveillance of other emerging triatominae species like R. pallescens, T. nitida, and T. ryckmani.

  17. Feeding and defaecation patterns in Triatoma sordida

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    LB Crocco

    1996-08-01

    Full Text Available Triatoma sordida is a peridomestic Triatominae that could play an important role in the transmission of Trypanosoma cruzi, although its vectorial competence is not well known. The aim of this work was to evaluate two aspects of the vectorial competence: the feeding behaviour and defaecation patterns, and to compare them with T. infestans. The feeding and defaecation patterns were studied in adults and fifth instar nymphs of T. sordida fed ad libitum on a restrained pigeon. The results showed how the blood meal size controls excretion behaviour. Blood intake and time to first defaecation showed a significant negative correlation. Adults and nymphs frequently defaecated during the blood meal, reaching the maximum frequency within the first 10 minutes.

  18. Control of Chagas disease vectors

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    Ramsey JM

    2003-01-01

    Full Text Available Most Latin American countries are making dramatic progress in controlling Chagas disease, through a series of national and international initiatives focusing on elimination of domestic populations of Triatominae, improved screening of blood donors, and clinical support and treatment of persons infected with Trypanosoma cruzi. Some countries, particularly Uruguay, Chile and Brazil, are sufficiently advanced in their programmes to initiate detailed planning of the subsequent phases of Chagas disease control, while others such as Peru, Ecuador, and Mexico, are currently applying only the initial phases of the control campaigns. In this review, we seek to provide a brief history of the campaigns as a basis for discussion of future interventions. Our aim is to relate operational needs to the underlying biological aspects that have made Chagas disease so serious in Latin America but have also revealed the epidemiological vulnerability of this disease.

  19. Encuesta sobre artropodos de interés médico en La Guajira, Colombia, Suramérica

    Directory of Open Access Journals (Sweden)

    Alberto Morales

    1987-12-01

    Full Text Available Durante la segunda mitad del año de 1982, se realizó una investigación acerca de artrópodos pertenecientes a la familia Culicidae y subfamilias Triatominae y Phlebotominae en algunas áreas urbanas y rurales del departamento de La Guajira, en la zona de influencia de la mina de carbón de El Cerrejón. Este artículo incluye todas las especies de artrópodos encontradas excepto los mosquitos de Genero Haemagogus, los cuales fueron informados en una publicación previa. Varias especies reconocidas vectoras de algunos arbovirus, malaria, tripanosomiasis y leishmaniasis fueron encontradas.

  20. Fauna cavernícola brasileira: composição e caracterização preliminar

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    Eleonora Trajano

    1986-01-01

    Full Text Available In this study a number of caves from various Brazilian limestone regions were surveyed. The information gathered expands and improves that of our preliminary article, allowing a reasonable good picture of the Brazilian cave fauna. There doesn't seem to be any striking difference between the composition of the Brazilian cave fauna and that of the other tropical regions that have been studied. Animals commonly found throughout the studied area include: Phalangopsidae crickets, Reduviidae heteropterans, Polydesmida and Juliformida millipedes, Opilionida Laniatores, and spiders, particularly Scytodidae, Ctenidae, Theridiosomatidae and Pholcidae. Among the vertebrates the commonest are barts and catfishes. Amblypygi are common in all regions except São Paulo State, which is outside the group geographical distribution. Cockroaches are frequent in the warm caves to the north of Vale do Ribeira (São Paulo State where these animals are rarely seen. The cave fauna of the Vale do Ribeira is better Known than that of other Brazilian regions. Those small secretive species often found in Vale do Ribeira are probable also common elsewhere: beetles (partilarly the Carabidae, Leiodidae Catopinae, and, to a lesser exyent, the Pselaphidae and Otilodactylidae; dipterans (in special Chironomidae and Keroplatidae; and typically soil animals like collembolans and earthwormos. The sandstone cave fauna is basically the same found in limestone. The only difference seems to be the larger amount of batguano found in the former, conditioning larger populations of guano-feeding arthropods such as crickets and juliformid millipedes. The fauna of the entrance and twilight zone is characterized by the predominance of the Arachnida like opilionids Goniosominae and spiders Pholcidae, and heteropterans Reduviidae; the only typical dipteran of this fauna is the larval form of the fungus gnat Neoditomyia sp. (Mycetophiloidea. It was also observed a stratification within the

  1. Residual effect of a micro-encapsulated formulation of organophosphates and piriproxifen on the mortality of deltamethrin resistant Triatoma infestans populations in rural houses of the Bolivian Chaco region

    Directory of Open Access Journals (Sweden)

    Abraham Gemio Alarico

    2010-09-01

    Full Text Available The Bolivian Chaco is part of the endemic region of Chagas disease and an area where pyrethroid resistant Triatoma infestans (Hemiptera: Reduviidae populations has been reported. The World Health Organization identified these resistant populations as an important focus for research. The objective of this study was to evaluate the residual effect of a micro-encapsulated formulation containing organophosphate active ingredients and a juvenile hormone analogue (Inesfly 5A IGR on the mortality of T. infestans. Studies took place in rural houses of the Bolivian Chaco that were treated up to 34 months before and evaluated the susceptibility to pyrethroids of the offspring of field collected insects. Thirty houses were randomly selected within three communities to carry out wall bio-assays with T. infestans nymphs. Mortality was recorded 24, 48 and 72 h after wall contact. Eggs laid by females collected in the area were used to obtain first-instar nymphs and carry out pyrethroid susceptibility tests. The wall bio-assays showed that the micro-encapsulated insecticide eliminates T. infestans populations and produces detectable mortality of insects exposed to walls treated 34 months prior to the tests. The discriminant dose of deltamethrin (0.01 mg/mL showed 65% nymph survival, whereas at the highest tested dose (1.0 mg/mL 14% of the nymphs survived. These results show that Inesfly 5A IGR is an appropriate tool for the elimination of intradomestic and peridomestic populations of T. infestans resistant to pyrethroids.

  2. Demographic effects of deltamethrin resistance in the Chagas disease vector Triatoma infestans.

    Science.gov (United States)

    Germano, M D; Picollo, M I

    2016-12-01

    Triatoma infestans (Heteroptera: Reduviidae) Klug is the main vector of Chagas disease in Latin America. Resistance to deltamethrin was reported in Argentina and recently associated with reproductive and longevity trade-offs. The objectives of the present study were to describe the demographic consequences of deltamethrin resistance in T. infestans and to establish possible target stages for chemical control in susceptible and resistant colonies. A stage-classified matrix model was constructed based on the average stage length for susceptible, resistant and reciprocal matings' progeny. The differences between colonies were analysed by prospective and retrospective analysis. The life table parameters indicated reduced fecundity, fertility and population growth in resistant insects. The retrospective analysis suggested the latter was associated with lower reproductive output and increased fifth-instar nymph stage length. The prospective analysis suggested that the adult stage should be the main target for insecticide control. Although, fifth-instar nymphs should also be targeted when resistance has been detected. The presented results show demographic effects of deltamethrin resistance in T. infestans. While the older stages could be the main targets for chemical control, this approach is impeded by their higher tolerance to insecticides. It is concluded that the different mode of action insecticides would be more effective than a dose increase for the control of deltamethrin-resistant T. infestans. © 2016 The Royal Entomological Society.

  3. Relationships between altitude, triatomine (Triatoma dimidiata) immune response and virulence of Trypanosoma cruzi, the causal agent of Chagas' disease.

    Science.gov (United States)

    DE Fuentes-Vicente, J A; Cabrera-Bravo, M; Enríquez-Vara, J N; Bucio-Torres, M I; Gutiérrez-Cabrera, A E; Vidal-López, D G; Martínez-Ibarra, J A; Salazar-Schettino, P M; Córdoba-Aguilar, A

    2017-03-01

    Little is known about how the virulence of a human pathogen varies in the environment it shares with its vector. This study focused on whether the virulence of Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae), the causal agent of Chagas' disease, is related to altitude. Accordingly, Triatoma dimidiata (Hemiptera: Reduviidae) specimens were collected at three different altitudes (300, 700 and 1400 m a.s.l.) in Chiapas, Mexico. The parasite was then isolated to infect uninfected T. dimidiata from the same altitudes, as well as female CD-1 mice. The response variables were phenoloxidase (PO) activity, a key insect immune response, parasitaemia in mice, and amastigote numbers in the heart, oesophagus, gastrocnemius and brain of the rodents. The highest levels of PO activity, parasitaemia and amastigotes were found for Tryp. cruzi isolates sourced from 700 m a.s.l., particularly in the mouse brain. A polymerase chain reaction-based analysis indicated that all Tryp. cruzi isolates belonged to a Tryp. cruzi I lineage. Thus, Tryp. cruzi from 700 m a.s.l. may be more dangerous than sources at other altitudes. At this altitude, T. dimidiata is more common, apparently because the conditions are more beneficial to its development. Control strategies should focus activity at altitudes around 700 m a.s.l., at least in relation to the region of the present study sites. © 2016 The Royal Entomological Society.

  4. Active dispersal of Triatoma infestans and other triatomines in the Argentinean arid Chaco before and after vector control interventions.

    Science.gov (United States)

    Abrahan, Luciana; Gorla, David; Catalá, Silvia

    2016-06-01

    Peridomestic structures are considered the main sites where Triatoma infestans (Hemiptera: Reduviidae) remain and disperse, representing the first risk factor for intradomestic invasion, even after vector control activities. This study analyzed T. infestans dispersal during vector control interventions in six rural houses of the arid Chaco (La Rioja, Argentina). Flying and walking dispersers were captured during five months of two consecutive warm seasons after insecticide spraying of intra- and peridomiciles. These data were compared with previous published data in the same scenario but without insecticide spraying in peridomiciles. Recorded climatic conditions were favorable for active dispersion during the study. Total number of T. infestans dispersers moving among domestic habitats decreased after insecticide spraying. Sylvatic triatomines T. guasayana, T. eratyrusiformis, T. garciabesi, and T. platensis, not targeted by insecticide spraying, were captured simultaneously within peridomestic areas and showed higher invasion pressure than T. infestans. Adult T. infestans peridomestic populations showed high nutritional status, indicating low dispersion probability. Some peridomiciles remained infested at the end of the study. However, no intradomiciles were recolonized. These results suggest that there is a low probability of intradomestic recolonization by active dispersion from peridomiciles during 15 months post-spraying. © 2016 The Society for Vector Ecology.

  5. Sperm dimorphism in the Triatoma brasiliensis species complex and its applications.

    Science.gov (United States)

    Baffa, A F; Camara, D C P; Santos-Mallet, J R; DA Silva, E R; Costa, J; Freitas, S P C

    2017-06-01

    Morphological and structural features of the sperm of the Triatoma brasiliensis Neiva, 1911 (Hemiptera: Reduviidae) species complex were examined in this first study investigating the sperm of Heteroptera and the genus Triatoma. Males were dissected and their seminal vesicles removed. For measurement, seminal vesicles were squashed on glass slides, spread, fixed and observed under a photomicroscope. The images were analysed and measures of sperm were made. Data were analysed using one-way analysis of variance and Tukey's test to detect differentiation among taxa. Furthermore, seminal vesicles were prepared for studies of transmission electron microscopy. All taxa studied showed polymorphic (short and long) sperm. The sperm of Triatoma brasiliensis macromelasoma was significantly longer (in total length) than that of the other four members of the complex, which supports the hypothesis of hybrid speciation of this member of the complex as an increase in the size of typical hybrids under heterosis was previously shown. The sperm cells of the five taxa have similar ultrastructural morphology. The ultrastructural features observed confirm the hypothesis, raised by previous studies, that they are synapomorphic to the suborder Heteroptera. © 2017 The Royal Entomological Society.

  6. On triatomines, cockroaches and haemolymphagy under laboratory conditions: new discoveries

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    Pamela Durán

    Full Text Available For a long time, haematophagy was considered an obligate condition for triatomines (Hemiptera: Reduviidae to complete their life cycle. Today, the ability to use haemolymphagy is suggested to represent an important survival strategy for some species, especially those in genus Belminus. As Eratyrus mucronatus and Triatoma boliviana are found with cockroaches in the Blaberinae subfamily in Bolivia, their developmental cycle from egg to adult under a “cockroach diet” was studied. The results suggested that having only cockroach haemolymph as a food source compromised development cycle completion in both species. Compared to a “mouse diet”, the cockroach diet increased: (i the mortality at each nymphal instar; (ii the number of feedings needed to molt; (iii the volume of the maximum food intake; and (iv the time needed to molt. In conclusion, haemolymph could effectively support survival in the field in both species. Nevertheless, under laboratory conditions, the use of haemolymphagy as a survival strategy in the first developmental stages of these species was not supported, as their mortality was very high. Finally, when Triatoma infestans, Rhodnius stali and Panstrongylus rufotuberculatus species were reared on a cockroach diet under similar conditions, all died rather than feeding on cockroaches. These results are discussed in the context of the ecology of each species.

  7. The hunter becomes the hunted: when cleptobiotic insects are captured by their target ants

    Science.gov (United States)

    Dejean, Alain; Carpenter, James M.; Corbara, Bruno; Wright, Pamela; Roux, Olivier; LaPierre, Louis M.

    2012-04-01

    Here we show that trying to rob prey (cleptobiosis) from a highly specialized predatory ant species is risky. To capture prey, Allomerus decemarticulatus workers build gallery-shaped traps on the stems of their associated myrmecophyte, Hirtella physophora. We wondered whether the frequent presence of immobilized prey on the trap attracted flying cleptoparasites. Nine social wasp species nest in the H. physophora foliage; of the six species studied, only Angiopolybia pallens rob prey from Allomerus colonies. For those H. physophora not sheltering wasps, we noted cleptobiosis by stingless bees ( Trigona), social wasps ( A. pallens and five Agelaia species), assassin bugs (Reduviidae), and flies. A relationship between the size of the robbers and their rate of capture by ambushing Allomerus workers was established for social wasps; small wasps were easily captured, while the largest never were. Reduviids, which are slow to extract their rostrum from prey, were always captured, while Trigona and flies often escaped. The balance sheet for the ants was positive vis-à-vis the reduviids and four out of the six social wasp species. For the latter, wasps began by cutting up parts of the prey's abdomen and were captured (or abandoned the prey) before the entire abdomen was retrieved so that the total weight of the captured wasps exceeded that of the prey abdomens. For A. pallens, we show that the number of individuals captured during attempts at cleptobiosis increases with the size of the Allomerus' prey.

  8. Population dynamic of the swallowtail butterfly, Papilio polytes (Lepidoptera: Papilionidae in dry and wet seasons

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    SUWARNO

    2010-01-01

    Full Text Available Suwarno (2010 Population dynamic of the swallowtail butterfly, Papilio polytes (Lepidoptera: Papilionidae in dry and wet seasons. Biodiversitas 11: 19-23. The population dynamic of Papilio polytes L. (Lepidoptera: Papilionidae in dry and wet seasons was investigated in the citrus orchard in Tasek Gelugor, Pulau Pinang, Malaysia. Population of immature stages of P. polytes was observed alternate day from January to March 2006 (dry season, DS, from April to July 2006 (secondary wet season, SWS, and from October to December 2006 (primary wet season, PWS. The population dynamics of the immature stages of P. polytes varied between seasons. The immature stages of P. polytes are more abundance and significantly different in the PWS than those of the DS and the SWS. The larval densities in all seasons decreased with progressive development of the instar stages. Predators and parasitoids are the main factor in regulating the population abundance of immature stages of P. polytes. There were positive correlations between the abundance of immature stages of P. polytes and their natural enemies abundance in each season. Ooencyrtus papilioni Ashmead (Hymenoptera: Encyrtidae is the most egg parasitoid. Oxyopes quadrifasciatus L. Koch. and O. elegans L. Koch. (Araneae: Oxyopidae are the main predators in the young larvae, meanwhile Sycanus dichotomus Stal. (Heteroptera: Reduviidae, Calotes versicolor Fitzinger (Squamata: Agamidae, birds and praying mantis attacked the older larvae.

  9. Excretion/defecation patterns in Triatoma infestans populations that are, respectively, susceptible and resistant to deltamethrin.

    Science.gov (United States)

    Lobbia, P; Calcagno, J; Mougabure-Cueto, G

    2018-02-12

    Pyrethroid resistance has been detected in Triatoma infestans (Klug) (Hemiptera: Reduviidae) specimens from different areas of Argentina and Bolivia. Genes conferring resistance can have a pleiotropic effect with epidemiological and evolutionary consequences. This research studied excretion/defecation patterns in deltamethrin-resistant T. infestans in order to elucidate its biological performance, adaptive consequences and role in the transmission of Chagas' disease. One deltamethrin-susceptible strain and two deltamethrin-resistant strains were used. Fifth-instar nymphs were fed ad libitum and their defecations recorded during and after the first or second feeding in the stadium. Resistant insects began to defecate later, defecated less, showed a lower proportion of defecating individuals and lower defecation indices compared with susceptible insects during the first hour after feeding. The number of bloodmeals in the stadium did not affect the main variables determining the pattern of defecation. The present study suggests that alterations in the excretion/defecation pattern in resistant insects entail an adaptive cost and, considering only this pattern, determine a lower capacity for transmission of Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) compared with susceptible insects. © 2018 The Royal Entomological Society.

  10. A methodology based on insecticide impregnated filter paper for monitoring resistance to deltamethrin in Triatoma infestans field populations.

    Science.gov (United States)

    Remón, C; Lobbia, P; Zerba, E; Mougabure-Cueto, G

    2017-12-01

    The domiciliary presence of Triatoma infestans (Klug) (Hemiptera: Reduviidae) after control interventions was reported in recent years. Toxicological studies showed high levels of resistance to pyrethroids suggesting resistance as one of the main causes of deficient control. The aim of the present study was to develop a protocol to test resistance to deltamethrin in T. infestans collected from the field by discriminate concentration. To evaluate field insects, the effect of age (early vs. later) and nutritional state (starved vs. fed) on the deltamethrin susceptibility of each developmental stage was studied. Topical and insecticide impregnated paper bioassays were used. Using the impregnated paper, the susceptibility to deltamethrin was not affected by the age of the stadium and the nutritional states, and varied with the post-exposure time and with the different developmental stages. A discriminant concentration of deltamethrin (0.36% w/v) impregnated in filter paper was established for all developmental stages. Finally, the methodology and the discriminant concentration were evaluated in the laboratory showing high sensitivity in the discrimination of resistance. The present study developed a methodology of exposure to insecticide impregnated papers and proposes a protocol to test T. infestans in field populations with the aim to detect early evolution of resistance to deltamethrin. © 2017 The Royal Entomological Society.

  11. Ecological characteristics of Triatoma patagonica at the Southern limit of its distribution (Chubut, Argentina

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    Wisnivesky-Colli Cristina

    2003-01-01

    Full Text Available This study aimed at identifying the ecological characteristics of Triatoma patagonica Del Ponte 1929 (Hemiptera: Reduviidae and evaluating the epidemiological importance of this species at its southernmost distribution limit. We carried out two surveys in the Province of Chubut, in summer and in spring, 1998. In each survey, we interviewed local health care agents for triatomine recognition and reports of the bugs, followed by entomological searches in houses and peridomestic and silvatic biotopes. The presence of T. patagonica was confirmed in two of the five localities indicated by interview. In agreement with previous studies, all these positive localities were east of the 11°C isotherm, within the Monte phytogeographic province. Triatomine abundance and infestation levels (in peridomiciles and peridomestic biotopes were higher in summer than in spring, possibly reflecting adverse environmental conditions such as flood and cold winter weather. In the silvatic environment, we found three adult bugs under rocks in summer. In peridomestic sites bugs were only found associated with chickens, which were also the only blood meal source identified. Infection by Trypanosoma cruzi was not detected. We conclude that T. patagonica at its southernmost distribution limit does not represent a risk to public health due to its low abundance, lack of association with humans, and absence of T. cruzi infection.

  12. Chagas. From Exotic Tropical Disease to Pathology Globalized

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    Beatriz BASSO

    2016-09-01

    Full Text Available Chagas disease, whose aetiological agent is Trypanosoma cruzi, is one of the main endemic diseases in Latin America, ranking fourth regarding the number of lost life years due to death or disability in the area; nevertheless, it is among the so-called “neglected diseases”. Despite its rural origin, where it is transmitted through vector insects belonging to the Reduviidae family, it has nowadays also become a problem in urbanized areas and is becoming globalized through inter-human transmission, above all congenital, but also through transfusions and transplants. Chagas, a Hidden Affliction (Chagas, Un mal escondido, a documentary by Ricardo Preve, focuses on both aspects of the disease: the rural and the global one, including interviews with North American doctors and European researchers. A significant part of the film takes place in the USA, showing the worst consequence of the evolution of the disease, which is death by chagasic cardiopathy which, being a reality that takes place during filming, increases the sense of drama. In this paper we approach specific topics related to Chagas disease from a biomedical point of view, including comments related to the highlights of the film that are connected with such aspects. Towards the end, there is mention of the film Houses of Fire (Casas de fuego and of certain illustrative aspects concerning the life of Dr Salvador Mazza and the Argentine Mission of Regional Pathology Studies (MEPRA, topics that have already been dealt with in this. 

  13. An entomological and seroepidemiological study of the vectorial-transmission risk of Chagas disease in the coast of northern Chile.

    Science.gov (United States)

    González, C R; Reyes, C; Canals, A; Parra, A; Muñoz, X; Rodríguez, K

    2015-12-01

    Four species of triatomines are known from Chile: Triatoma infestans Klug, Mepraia spinolai Porter, M. gajardoi Frías, Henry & González, and M. parapatrica Frías (Hemiptera: Reduviidae), the last three are endemic. The geographical distribution of M. gajardoi includes the coastal areas in the north of Chile between 18° and 21°S, an area with both a resident workforce and summer-season visitors. A study was developed to assess the risk of vectorial transmission of Chagas disease by M. gajardoi in hut settlements on the coast of the Tarapacá Region, in particular in Caleta San Marcos and Caleta Río Seco. The study comprised fingerstick sampling of 95 persons, venous samples from 29 domestic dogs and capture of 52 triatomines, from both fishing coves. The samples were analysed by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques. The results show that, of the total number of persons studied, 100% were negative for Trypanosoma cruzi Chagas (Trypanosomatida: Trypanosomatidae) antibodies, 10.34% of canids were positive for the antibody and 5.8% of M. gajardoi were infected to the PCR technique. The presence of this species in areas close to human settlements constitutes a risk to human populations established on the coast of northern Chile. © 2015 The Royal Entomological Society.

  14. Cuticular hydrocarbon pattern as a chemotaxonomy marker to assess intraspecific variability in Triatoma infestans, a major vector of Chagas' disease.

    Science.gov (United States)

    Calderón-Fernández, G M; Girotti, J R; Juárez, M P

    2012-06-01

    Triatoma infestans Klug (Hemiptera: Reduviidae) populations were sampled in various localities throughout most of the species' geographic range of distribution in Argentina, Bolivia, Paraguay and Peru. In order to contribute to understanding of the diversity and population structure of this major vector of Chagas' disease, cuticular hydrocarbon (CHC) profiles were analysed by capillary gas chromatography and variations evaluated by statistical methods of classification and ordination. High levels of intrapopulation variation were detected, along with low levels of variability among populations. Based on relative amounts of the major odd-numbered straight-chain hydrocarbons n-C27 to n-C33, two hydrocarbon phenotypes were evident, unequally distributed along the species' geographic range. Analysis of CHC patterns showed that T. infestans populations segregate into two major groups consisting of an Andean group, which comprises specimens from Peru and most parts of Bolivia, and a non-Andean group, which includes all specimens from Argentina and Paraguay, together with those from Tarija (Bolivia). Pyrethroid-resistant and -susceptible specimens were differentiated based on relative amounts of some straight and monomethyl-branched hydrocarbon components. © 2011 The Authors. Medical and Veterinary Entomology © 2011 The Royal Entomological Society.

  15. Environmental Determinants of the Distribution of Chagas Disease Vector Triatoma dimidiata in Colombia

    Science.gov (United States)

    Parra-Henao, Gabriel; Quirós-Gómez, Oscar; Jaramillo-O, Nicolas; Cardona, Ángela Segura

    2016-01-01

    Triatoma dimidiata (Hemiptera: Reduviidae) is a secondary vector of Trypanosoma cruzi in Colombia and represents an important epidemiological risk mainly in the central and oriental regions of the country where it occupies sylvatic, peridomestic, and intradomestic ecotopes, and because of this complex distribution, its distribution and abundance could be conditioned by environmental factors. In this work, we explored the relationship between T. dimidiata distribution and environmental factors in the northwest, northeast, and central zones of Colombia and developed predictive models of infestation in the country. The associations between the presence of T. dimidiata and environmental variables were studied using logistic regression models and ecological niche modeling for a sample of villages in Colombia. The analysis was based on the information collected in field about the presence of T. dimidiata and the environmental data for each village extracted from remote sensing images. The presence of Triatoma dimidiata (Latreille, 1811) was found to be significantly associated with the maximum vegetation index, minimum land surface temperature (LST), and the digital elevation for the statistical model. Temperature seasonality, annual precipitation, and vegetation index were the variables that most influenced the ecological niche model of T. dimidiata distribution. The logistic regression model showed a good fit and predicted suitable habitats in the Andean and Caribbean regions, which agrees with the known distribution of the species, but predicted suitable habitats in the Pacific and Orinoco regions proposing new areas of research. Improved models to predict suitable habitats for T. dimidiata hold promise for spatial targeting of integrated vector management. PMID:26856910

  16. Experimental transmission of Trypanosoma cruzi through the genitalia of albino mice

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    Herrera Leidi

    2001-01-01

    Full Text Available Trypanosoma cruzi is usually transmitted by contact with the excreta of infected Triatominae; among non-vectorial infections, direct transmission through coitus has been proposed. We investigated this possibility by instilling, through the external meatus of the vagina and the penis of previously anesthetized NMRI albino mice, blood of mice infected with strains isolated from Didelphis marsupialis (opossum, strain CO57, Rattus rattus (rat, strain CO22 and human (strain EP. Some animals were allowed to copulate the same day of the instillation. In other experiments, the strains were inoculated in the scrotum. To determine the effect of immunosuppression, some mice were treated with cyclophosphamide 30 days post-instillation. Controls were instilled orally and ocularly. Vaginal instillation with strain CO22 produced systemic infection with tropism to the heart, skeletal muscle, skin, duodenum, pancreas, ovary and sternum. Scrotal inoculation with strain EP likewise invaded liver, spleen, lung, lymph nodes and urogenital organs; while strain CO57 invaded skeletal and cardiac muscle, pancreas, testis, and vas deferens. Penile infection with strain CO22 was detected by xenodiagnosis. Immunosuppression did not increase parasitemia of vaginally infected mice or controls. Mating did not produce infection. Our results show that contact of blood trypomastigotes of T. cruzi with genital mucosa can produce blood and tissue infections. These results are discussed in relation to reports of frequent experimental tropism of T. cruzi toward urogenital organs.

  17. Spatial patterns and eco-epidemiological systems – part II: characterising spatial patterns of the occurrence of the insect vectors of Chagas disease based on remote sensing and field data

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    Emmanuel Roux

    2011-11-01

    Full Text Available While the former part of this back-to-back paper dealt with the identification of multi-scale spatial patterns associated with the presence, abundance and dispersion of the insect vectors (Triatominae of Chagas disease, this latter part examines the need for pattern characterisation by means of detailed data on environmental, residential, peri-domiciliary and human behaviour. The study site was, in both cases, a single village situated in Bahia, Brazil, wherefrom the data were collected through field observation and a standardised questionnaire, while the environmental characteristics were derived from satellite images and landscape characterisation. Following this, factorial analysis of mixed group (FAMG, an exploratory data analysis method, was applied to “mine” the huge dataset in a hierarchical way and to evaluate the relative impact of different factors such as the surrounding environment, the domiciliary/peri-domiciliary space properties and the presence of domestic animals. In the study village, five principal “districts” associated with different possible causes of infestation were identified. The results favour the role of depressions of the ground surface due to collapse of karstic subsoil (dolines and open rock faces as infestation sources, vector attraction by outdoor lighting, risk of insect domiciliation in dwellings constructed without finishing materials and associated with apparent disorder. Ultimately, this study not only provides the basic information needed for decision-making and specification of vector control in the study village, but offers also a knowledge-base for more general control strategies in the region.

  18. Area-wide control of Chagas disease vectors in Latin America

    International Nuclear Information System (INIS)

    Schofield, C.J.

    2000-01-01

    Chagas disease (American trypanosomiasis) is now ranked by the World Bank as the most serious parasitic disease of the Americas, with a medical and economic impact far outranking even the combined effects of other parasitic diseases such as malaria and schistosomiasis (World Bank 1993). The infection is virtually impossible to cure and the disease is difficult and costly to treat. In contrast, transmission can be halted by eliminating the domestic insect vectors - large blood sucking reduviids of the subfamily Triatominae - and by improved screening of blood donors to minimise the risk of transfusional transmission (WHO 1991). Improved screening of blood banks requires appropriate legislation backed by a well-developed system of reference laboratories and standardised procedures, although to a large extent, this can be implemented in a progressive way from local to national levels (Schmunis 1991). By contrast, the key to success in Chagas disease vector control lies in the implementation of large-scale regional or international programmes coupled with long-term community-based vigilance. This is a classic intervention model beginning with a vertical intervention, the attack phase, in which all infested houses are sprayed by trained professionals, progressively backed by a more horizontal community-based system where householders themselves can report the presence of any residual infestations for retreatment where necessary. Elimination of domestic vectors of Chagas disease is facilitated by their slow reproductive rates and limited genetic variability, but is hampered by the ease of passive transport of the insects from one house to another, even across state and international boundaries (Schofield 1994). For this reason, international collaboration is particularly important in Chagas disease vector control. Since early trials in the 1940s, there have been many local and regional campaigns designed to control domestic populations of Triatominae, especially in

  19. Impact of a community-based bug-hunting campaign on Chagas disease control: a case study in the department of Jalapa, Guatemala

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    Yoshioka, Kota

    2013-01-01

    Chagas disease control requires an innovative approach to strengthen community participation in vector surveillance. This paper presents a case study of a community-based bug-hunting campaign in Guatemala. The campaign was implemented in 2007 in the following three stages: (i) a four week preparation stage to promote bug-hunting, (ii) a one week bug-hunting stage to capture and collect bugs and (iii) a 10 week follow-up stage to analyse the bugs and spray insecticide. A total of 2,845 bugs were reported, of which 7% were Triatominae vectors, such as Rhodnius prolixus and Triatoma dimidiata. The bug-hunting campaign detected a five-six-fold higher amount of vectors in one week than traditional community-based surveillance detects in one year. The bug-hunting campaign effectively detected vectors during a short period, provided information to update the vector infestation map and increased community and political awareness regarding Chagas disease. This approach could be recommended as an effective and feasible strategy to strengthen vector surveillance on a larger scale. PMID:23579801

  20. Monitoring the domiciliary and peridomiciliary invasion process of Triatoma rubrovaria in the State of Rio Grande do Sul, Brazil

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    Almeida Carlos Eduardo

    2000-01-01

    Full Text Available The presence of Triatoma rubrovaria in Brazil has only been confirmed in the States of Paraná and Rio Grande do Sul (RS, where it is found naturally infected with Trypanosoma cruzi. In the wild environment it occurs in rocky habitats and has an eclectic diet, feeding from cockroaches, reptiles and mammals. Data from the Chagas Disease Control Program obtained by the Fundação Nacional de Saúde, between 1975 and 1997, indicate a growing domiciliary and peridomiciliary invasion of T. rubrovaria in RS, where it has become the most frequently Triatominae species captured in this state since the control of Triatoma infestans. In order to monitor this process, we analyzed collection data derived from 22 years of control campaigns against T. infestans. Collection data for triatomines from domestic habitats show an inverse relationship, with high numbers of T. infestans and low numbers of T. rubrovaria during 1976-1987, compared to the following ten years, 1986-1997, when the number of T. infestans dropped drastically and that of T. rubrovaria increased. There are no consistent indications of intradomiciliary colonization by T. rubrovaria, since only low numbers of nymphs have been captured in the intradomiciliary ecotopes. Nevertheless, this species appears to have preadaptive characteristics for anthropic ecotopes, and should be kept under constant epidemiological surveillance.