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.

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.

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

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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

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.

Biogeography of Triatominae (Hemiptera: Reduviidae in Ecuador: implications for the design of control strategies

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Abad-Franch Fernando

2001-01-01

Full Text Available Chagas disease control strategies strongly depend on the triatomine vector species involved in Trypanosoma cruzi transmission within each area. Here we report the results of the identification of specimens belonging to various species of Triatominae captured in Ecuador (15 species from 17 provinces and deposited in the entomological collections of the Catholic University of Ecuador (Quito, Instituto Oswaldo Cruz (Brazil, the Natural History Museum London (UK, the London School of Hygiene and Tropical Medicine (UK, the National Institute of Hygiene (Quito, and the Vozandes Hospital (Quito. A critical review of published information and new field records are presented. We analysed these data in relation to the life zones where triatomines occur (11 life zones, excluding those over 2,200 m altitude, and provide biogeographical maps for each species. These records are discussed in terms of epidemiological significance and design of control strategies. Findings relevant to the control of the main vector species are emphasised. Different lines of evidence suggest that Triatoma dimidiata is not native to Ecuador-Peru, and that synanthropic populations of Rhodnius ecuadoriensis in southern Ecuador-northern Peru might be isolated from their sylvatic conspecifics. Local eradication of T. dimidiata and these R. ecuadoriensis populations might therefore be attainable. However, the presence of a wide variety of native species indicates the necessity for a strong longitudinal surveillance system.

Presence of Triatominae (Hemiptera, Reduviidae and Risk of Transmission of Chagas Disease in Colima, México

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Espinoza-Gómez Francisco

2002-01-01

Full Text Available With the purpose of evaluating the risk of transmission of the Chagas disease in the State of Colima, México, an entomological survey was performed to obtain triatominae and the rate of infection by Trypanosoma cruzi determined by examination of its dejections. Two hundred eighteen houses located in 16 villages were sampled. In each house the intradomestic and peridomestic habitats were examined by the man-hour-house method, sensor boxes and mouse-baited traps. Also, 12 silvatic places were explored around the same areas using the same techniques as the ones sampled. In total, 456 specimens were captured, of which 139 correspond to Triatoma phyllosoma pallidipennis; 80 to T. p. longipennis; one specimen of T. dimidiata and 236 nymphs of Triatoma sp. Two hundred ninety seven insects were captured in the intradomestic habitat, 132 in the peridomestic and 26 in the silvatic. The index of positive houses was 27%, located in the central area of the state. The rate of natural infection with T. cruzi showed 25.6%. This results confirmed the presence of two important vectors of the Chagas disease in Colima. Its preference for the domestic habitat and its high levels of natural infection with T. cruzi suggested the existence of a significant risk for its transmission in this area of the country.

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.

Exploring the Role of Rhodtestolin, A Cardio-Inhibitor from the Testes of Rhodnius prolixus, in Relation to the Structure and Function of Reproductive Organs in Insect Vectors of Chagas Disease

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Marli Maria Lima

2013-10-01

Full Text Available Rhodtestolin is a cardio-inhibitor that was first discovered in testes extracts of the blood-feeding insect, Rhodnius prolixus. Its role in reproduction remains unconfirmed, but if delivered to the female during spermatophore formation, it may serve to calm the female and/or relax the vaginal muscles to facilitate delivery and storage of the spermatophore. We describe here the anatomy of reproductive organs in R. prolixus and show that rhodtestolin is present in a low-molecular weight fraction of testes extracts separated by gel filtration, as well as in spermatophores delivered to the female during spermatophore formation. We also report that a rhodtestolin-like factor is present in the testes of R. brethesi, Triatoma dimidiata, T. klugi and Nesotriatoma bruneri, other Reduviidae, which are vectors of Chagas disease. Male secretions in insects are known to modify female behavior after copulation, and the presence of rhodtestolin in several genera of Reduviidae suggests that it plays an important role in reproductive success. Determining this role could lead to developing additional population control strategies for these bugs.

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.

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

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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.

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

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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.

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.

Distribuição espacial de populações de triatomíneos (Hemiptera: Reduviidae em palmeiras da espécie Mauritia flexuosa no Distrito Federal, Brasil Spatial distribution of Triatominae populations (Hemiptera: Reduviidae in Mauritia flexuosa palm trees in Federal District of Brazil

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Rodrigo Gurgel-Gonçalves

2004-06-01

Full Text Available Para determinar e analisar a distribuição espacial de populações silvestres de triatomíneos no Distrito Federal, Brasil, foram amostradas 150 palmeiras da espécie Mauritia flexuosa em seis veredas de diferentes paisagens (silvestre, rural e periurbana na estação chuvosa. Os triatomíneos foram identificados morfologicamente, separados por sexo e estadio ninfal e examinados para verificar infecção por Trypanosoma cruzi e Trypanosoma rangeli. Vinte e oito (18,6% palmeiras estavam infestadas por Rhodnius neglectus e 14 (9,5% por Psammolestes tertius. A freqüência dessas espécies em palmeiras com e sem ninhos foi significativamente diferente, sendo superior nas palmeiras com ninhos de aves e mamíferos na copa. O maior número médio de insetos/palmeira foi observado nas áreas rurais, com estimativas de até 838 insetos/hectare. A composição etária das espécies apresentou um padrão diferente, Rhodnius neglectus com predomínio de ninfas e Psammolestes tertius com predomínio de adultos, sendo que muitos ovos de Rhodnius neglectus foram coletados indicando um evento reprodutivo em fevereiro de 2003. Entre os ninhos encontrados nas palmeiras, o do pássaro Phacellodomus ruber (Furnariidae apresentou as maiores abundâncias de triatomíneos, ocorrendo em 42% das palmeiras. A abundância relativa de Rhodnius neglectus e Psammolestes tertius foi maior em áreas rurais que possuíram maior número de ninhos nas palmeiras e menor densidade de palmeiras por hectare. Nenhum dos 96 triatomíneos examinados estava infectado por Trypanosoma cruzi ou Trypanosoma rangeli, apesar de encontrarmos infecção de Rhodnius neglectus por esses parasitas em estudos anteriores.To determine and analyze the distribution of Triatominae sylvatic populations in the Federal District of Brazil, 150 Mauritia flexuosa palm trees were sampled in six veredas of different landscapes (sylvatic, rural and peri-urban in the rainy season. Triatomines were

Changes associated with laboratory rearing in antennal sensilla patterns of Triatoma infestans, Rhodnius prolixus, and Rhodnius pallescens (Hemiptera, Reduviidae, Triatominae

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Catalá SS

2004-01-01

Full Text Available We examined changes in the array of antennal sensilla of three species of Triatominae (Triatoma infestans, Rhodnius prolixus, and R. pallescens following their establishment for different periods in laboratory culture. In each case, the laboratory colonies were compared with conspecific samples taken directly from the field, by quantitative analysis of the sensilla arrays on the three distal segments of the antenna in terms of the densities of three types of chemoreceptors (basiconics and thick and thin walled trichoids and one type of mechanoreceptor (bristles. Sensilla densities were compared by ANOVA or non-parametric tests, and by multivariate discriminant analysis. Strains of the same species reared in different laboratories showed significant differences in their sensilla arrays, especially when compared to field-collected material from the same geographic origin. A Bolivian strain of T. infestans reared in the laboratory for 15 years and fed at monthly intervals, showed greatest differences from its conspecific wild forms, especially in terms of reductions in the number of chemoreceptors. By contrast, an Argentine strain of T. infestans reared for 25 years in the laboratory and fed weekly, showed a relative increase in the density of mechanoreceptors. A Colombian strain of R. prolixus reared for 20 years and fed weekly or fortnightly, showed only modest differences in the sensilla array when compared to its wild populations from the same area. However, a Colombian strain of R. pallescens reared for 12 years and fed fortnightly, did show highly significant reductions in one form of chemoreceptor compared to its conspecific wild populations. For all populations, multivariate analysis clearly discriminated between laboratory and field collected specimens, suggesting that artificial rearing can lead to modifications in the sensory array. This not only supports the idea of morphological plasticity in these species, but also suggests caution in

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

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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

Triatoma ryckmani (Hemiptera: Reduviidae) in the epiphyte Tillandsia xerographica (Bromeliaceae) in the semiarid region of Guatemala.

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Marroquín, Ricardo; Monroy, Carlota; Jaenson, Thomas G T

2004-05-01

For the first time, the reduviid bug Triatoma ryckmani Zeledón and Ponce (Hemiptera; Reduviidae) was recorded to inhabit the epiphyte Tillandsia xerographica Rohweder (Bromeliaceae) in the semiarid region of Guatemala. These bromeliads grow mainly in drought-resistant trees with rough bark such as Pereskia lychnidiflora (Cactaceae). In our study site, we investigated 30 T. xerographica, and 53 specimens of T. ryckmani were found. Most T. ryckmani (68.5%) were unfed. Ants (Formicidae) were the predominant (92.2%) insect taxon in T. xerographica. Other insects such as Blattidae (3.0%), Reduviidae (T. ryckmani: 2.5%), Blaberidae (2.2%), Gryllidae (0.1%), and Acrididae (0.1%) were recorded in the bromeliads. T. xerographica is illegally commercialized without previous inspection. This may cause accidental introduction of T. ryckmani to houses and to other countries.

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

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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

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.

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…

Flight Muscle Dimorphism and Heterogeneity in Flight Initiation of Field-Collected Triatoma infestans (Hemiptera: Reduviidae)

OpenAIRE

Gurevitz, Juan M.; Kitron, Uriel; Gürtler, Ricardo E.

2007-01-01

Recent experiments demonstrated that most field-collected Triatoma infestans (Klug) (Hemiptera: Reduviidae) adults from northern Argentina either never initiated flight or did so repeatedly in both sexes. This pattern could not be explained by sex, adult age, weight, weight-to-length ratio (W/L), or chance. We examined whether bugs that never initiated flight possessed developed flight muscles, and whether flight muscle mass relative to total body mass (FMR) was related to the probability of ...

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; 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.

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.

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.

A new species of Klabonosa Bouček (Hymenoptera: Pteromalidae) reared from eggs of Endochus sp. (Hemiptera: Reduviidae) from India.

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Gupta, Ankita; Yeshwanth, H M; Sureshan, P M

2018-04-23

The genus Klabonosa Bouček (Hymenoptera: Pteromalidae) is recorded for the first time from the Oriental region, with both sexes of K. indica Gupta, Sureshan Yeshwanth sp. n. reared from eggs of the assassin bug Endochus sp. (Hemiptera: Reduviidae) on Artocarpus heterophyllus Lam. (Moraceae). The male is formally described and illustrated for the first time for the genus.

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.

[Triatominae and Cactaceae: a risk for the transmission of the American trypanosomiasis in the peridomicilary space (Northeast Brazil)].

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Emperaire, L; Romaña, C A

2006-06-01

Field observations carried in semi-arid Brazil Northeast point out the frequent association, in the peridomiciliary space, between a cactus, Cereus jamacaru, the occurrence of nests in its branches and the occurrence of two species of insects vectors of Trypanosoma cruzi, pathogenic agent of Chagas disease: Rhodnius neglectus and Triatoma pseudomaculata. The analysis of the architectural variables of this Cactaceae shows that the presence of nests, and thus of insects, depends on the traditional practices of management of this cactus. This study underlines the relevance of an integrated approach of the ecology of Triatominae for the identification of factors of risk.

Could the bug Triatoma sherlocki be vectoring Chagas disease in small mining communities in Bahia, Brazil?

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Almeida, C E; Folly-Ramos, E; Peterson, A T; Lima-Neiva, V; Gumiel, M; Duarte, R; Lima, M M; Locks, M; Beltrão, M; Costa, J

2009-12-01

Searches for Chagas disease vectors were performed at the type locality from which Triatoma sherlocki Papa et al. (Hemiptera: Reduviidae: Triatominae) was described in the municipality of Gentio do Ouro, in the state of Bahia, Brazil, and in a small artisan quarry-mining community approximately 13 km distant in a remote area of the same municipality. The latter site represents a new locality record for this species. Adults, nymphs and exuviae of T. sherlocki were found in 21% of human dwellings, indicating that the species is in the process of domiciliation. Prevalence of Trypanosoma cruzi infection in collected bugs was 10.8%. Simple predictive approaches based on environmental similarity were used to identify additional sites likely suitable for this species. The approach successfully predicted an additional five sites for the species in surrounding landscapes. Ecological and entomological indicators were combined to discuss whether this scenario likely represents an isolated case or an emerging public health problem.

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.

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

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.

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.

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.

Description of a newly discovered Triatoma infestans (Hemiptera: Reduviidae Foci in Ibipeba, State of Bahia, Brazil

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Renato Freitas Araújo

2014-07-01

Full Text Available Introduction Chagas disease transmitted by the Triatoma infestans was eradicated from Brazil in 2006. However, reports of triatomine foci threaten the control of Chagas disease. The goal of this study was to determine T. infestans foci in the City of Ibipeba, State of Bahia. Methods Triatominae specimens were collected in Ibipeba and entomologic indicators were calculated using indices of domiciliary infestation, density, and colonization. Results T. infestans foci was discovery in Ibipeba, State of Bahia. Approximately 95% of the specimens were discovered inside dwellings, of which 34% were T. infestans. This species was also discovered forming a colony in tree bark in the peridomicile. Conclusions Triatoma infestans foci in peridomestic ecotopes in Ibipeba, BA, indicate increased the risk of transmission Chagas disease.

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

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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.

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.

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.

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.

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

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

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

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Grasielle Caldas D‘Ávila Pessoa

2016-01-01

Full Text Available 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.

Hallazgo de Panstrongylus rufotuberculatus (Champion, 1899 (Hemiptera, Reduviidae, Triatominae en ambiente domiciliario en la Región Piura, Perú Intra-domiciliary capture of Panstrongylus rufotuberculatus (Champion, 1899 (Hemiptera, Reduviidae, Triatominae in Piura, Peru

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Edgard Marín

2007-09-01

Full Text Available Panstrongylus rufotuberculatus presenta una amplia distribución en América Central y del Sur con un comportamiento de especie silvestre. En el Perú ha sido registrado en Tumbes, Piura y Cuzco, siendo descrito en casas de localidades de este último departamento. En el presente trabajo se documenta evidencia de domiciliación de P. rufotuberculatus en la localidad de Chirinos-La Pareja, Distrito de Suyo, Provincia de Ayabaca, Región Piura, Perú (4º46'S, 79º93'W. Se capturaron 28 especímenes: 3 ninfas II, 4 ninfas III, 2 ninfas IV, 8 ninfas V, 3 machos y 8 hembras, lo que evidencia la existencia de una colonia intradomiciliar en "cuyeros" (criaderos de Cavia porcellus camas y paredes del dormitorio de la vivienda. Exámenes parasitológicos de heces evacuadas espontáneamente fueron negativos a infección natural por Trypanosoma cruzi. A pesar de que se ha reportado la presencia de P. rufotuberculatus en localidades de Tumbes y Piura, es la primera vez que se documenta su tendencia sinantrópica en la Región. La importancia de esta especie y posteriores investigaciones permitirán evaluar su etología y potencial vectorial de trypanosomiasis americana. Se recomienda una cuidadosa actividad de vigilancia entomo-epidemiológica para esta especie y las otras que coexisten simpátricamente, actualmente en esta región del norte de Perú.Panstrongylus rufotuberculatus is widely distributed in Central and South America. In Peru, it has been found in Tumbes, Piura, and Cuzco. The authors report the presence of P. rufotuberculatus in Chirinos-La Pareja, Suyo district, Ayabaca Province, Piura Region, Peru. Twenty-eight specimens were collected in two of 15 dwellings: three 2nd instar, four 3rd instar, two 4th instar, and eight 5th instar nymphs, three male and eight female, in an intra-domiciliary colony of guinea pigs (Cavia porcellus, raised indoors as a source of diet protein and beds and bedroom walls. None of the fecal samples were naturally infected with Trypanosoma cruzi. This is the first report of synanthropic presence of P. rufotuberculatus in the region. The finding emphasizes the need for careful entomological and epidemiological surveillance of this and other triatomine species in the Region.

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.

Life Cycle, Feeding, and Defecation Patterns of Panstrongylus chinai (Hemiptera: Reduviidae: Triatominae) Under Laboratory Conditions.

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Mosquera, Katherine D; Villacís, Anita G; Grijalva, Mario J

2016-07-01

Chagas disease is caused by the protozoan Trypanosoma cruzi Panstrongylus chinai (Del Ponte) is highly domiciliated in the Peruvian and Ecuadorian Andes and has been found naturally infected with T. cruzi The objective of this study was to describe the life cycle, feeding, and defecation patterns of P. chinai in the Loja province within southern Ecuador. To characterize its life cycle, a cohort of 70 individuals was followed from egg to adult. At each stage of development, prefeeding time, feeding time, weight of ingested meal, proportional weight increase, and the time to the first defecation were recorded. Panstrongylus chinai completed its development in 371.4 ± 22.3 d, (95% CI 355.4-387.4), which means that it is likely a univoltine species. Prefeeding time, feeding time, and weight of ingested meal increased as individuals developed through nymphal stages. Moreover, time to first defecation was shortest in the early nymphal stages, suggesting higher vector potential in the early developmental stages. Data obtained in this study represent an important advance in our knowledge of the biology of P. chinai, which should be considered as a secondary Chagas disease vector species in the Andean valleys of Loja (Ecuador) and in the north of Peru, and included in entomological surveillance programs. © 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.

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.

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.

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.

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.

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.

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.

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.

Spatial distribution of triatomines (Reduviidae: Triatominae in urban areas of the city of Salvador, Bahia, Brazil

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Karine de Souza O. Santana

2011-05-01

Full Text Available Environmental changes have a strong influence on the emergence and/or reemergence of infectious diseases. The city of Salvador, Brazil -currently the focus of a housing boom linked to massive deforestation- is an example in point as the destruction of the remaining areas of the Atlantic Forest around the city has led to an increased risk for Chagas disease. Human domiciles have been invaded by the triatomine vectors of Trypansoma cruzi, the flagellate protozoan causing Chagas disease, a problem of particular concern in urban/suburban areas of the city such as the Patamares sector in the north-east, where numbers of both the vector and human cases of the disease have increased lately. To control and prevent further deterioration of the situation, the control programme for Chagas disease, developed by the Bahia Center for Zoonosis Control, has divided the area into a grid of designated surveillance units (ZIs that are subjected to vector examination. In six out of 98 of these ZIs, 988 triatomes were collected and georeferenced during the 3-year period between 2006 and 2009. The hottest months, that are also generally the driest, showed the highest numbers of triatomines with Triatoma tibiamaculata being the predominant species (98.3% with Panstrongylus geniculatus present only occasionally (0.6%. Fifty-four percent of all triatomines captured were found inside the homes, and 48.6% out of 479 individuals in the affected ZIs selected for analysis tested positive for T. cruzi infection. The study presented here is a pioneering initiative to map the spatial distribution of triatomines based on geographical information systems with the additional aim of contributing to an expanded knowledge-base about T. cruzi and its vectors in urban areas and raise public health awareness of the risks involved.

Triatoma rubrovaria (Blanchard, 1843 (Hemiptera-Reduviidae-Triatominae III: patterns of feeding, defecation and resistance to starvation

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Carlos Eduardo Almeida

2003-04-01

Full Text Available Data from the Chagas Disease Control Program indicate a growing domiciliary and peridomiciliary invasion of Triatoma rubrovaria in the State of Rio Grande do Sul, where it has become the most frequent triatomine species captured there since the control of T. infestans. Bionomic characteristics that could influence the vectorial capacity of T. rubrovaria as vector of Trypanosoma cruzi were evaluated: patterns of (i feeding, (ii defecation, and (iii resistance to starvation, using insects fed on mice. Fifty three percent of the females showed a defecation pattern conducive to chagasic transmission, defecating either on or near the bite site. The averages of the resistance to starvation varied from 48.1 to 179 days, for the first and fifth nymphal stages, respectively. Our study shows that with respect to the patterns of feeding, defecation and resistance to fasting, T. rubrovaria presented similar rates to the ones observed for other effective vector species, such as T. infestans. Thus, based on our studies we conclude that T. rubrovaria has biological characteristics that can positively influence its capacity to become infected and transmit T. cruzi, and also to keep residual populations after chemical control interventions.

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.

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

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

2017-01-01

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.

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.

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.

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.

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

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.

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.

Mass rearing and augmentative biological control evaluation of Rhynocoris fuscipes (Hemiptera: Reduviidae) against multiple pests of cotton.

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Tomson, Majesh; Sahayaraj, Kitherian; Kumar, Vivek; Avery, Pasco B; McKenzie, Cindy L; Osborne, Lance S

2017-08-01

Rhynocoris fuscipes (Fab.) (Hemiptera: Reduviidae) is a generalist predator of cotton pests and is commonly found inhabiting cotton-growing regions in southern India. With the goal of integrating this predator in standard management practices used against cotton pests on a commercial scale, (1) we developed a protocol for adult group rearing of this predator inside micro-environmental cages (MECs), and (2) we evaluated the biocontrol potential of mass-produced predators against cotton pests under potted and field conditions. Higher fecundity and adult longevity of R. fuscipes was recorded in the MECs than under natural growing conditions. The reduviid predator preferred stones and fallen leaves as hiding places in the MECs. The predator showed a higher biocontrol potential during the night hours against two pests, Phenacoccus solenopsis Tinsley and Dysdercus cingulatus (Fab.), than during the day under potted conditions. Under field conditions, R. fuscipes significantly reduced the population of Aphis gossypii Glover, P. solenopsis, D. cingulatus and Helicoverpa armigera (Hübner) by 28, 70, 29 and 50%, respectively. No negative impact of R. fuscipes was reported on other natural enemies present in the cotton agroecosystem. Significantly higher crop yield and cost benefit ratio were observed in R. fuscipes-released plots than in the control plots. The results suggest that R. fuscipes can be mass produced efficiently under controlled conditions in MECs, and used in an integrated management program for multiple cotton pests. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

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.

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

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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

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

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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.

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.

Toxicity, repellency and flushing out in Triatoma infestans (Hemiptera: Reduviidae exposed to the repellents DEET and IR3535

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Mercedes M.N. Reynoso

2017-05-01

Full Text Available DEET and IR3535 are insect repellents present worldwide in commercial products; their efficacy has been mainly evaluated in mosquitoes. This study compares the toxicological effects and the behavioral responses induced by both repellents on the blood-sucking bug Triatoma infestans Klug (Hemiptera: Reduviidae, one of the main vectors of Chagas disease. When applied topically, the Median Lethal Dose (72 h for DEET was 220.8 µg/insect. Using IR3535, topical application of 500 µg/insect killed no nymphs. The minimum concentration that produced repellency was the same for both compounds: 1,15 µg/cm2. The effect of a mixture DEET:IR3535 1:1 was similar to that of their pure components. Flushing out was assessed in a chamber with a shelter containing groups of ten nymphs. The repellents were aerosolized on the shelter and the number of insects leaving it was recorded for 60 min. During that time, 0.006 g/m3 of the positive control tetramethrin flushed out 76.7% of the nymphs, while 1.76 g/m3 of DEET or IR3535 flushed out 30 and 0%, respectively. The concentrations required for both compounds to produce toxicity or flushing out are too high to have any practical applications. However, they showed a promising repellency. Additional research should be done to evaluate their possible use for personal protection against T. infestans bites.

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.

Harvesting Venom Toxins from Assassin Bugs and Other Heteropteran Insects.

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Walker, Andrew Allan; Rosenthal, Max; Undheim, Eivind E A; King, Glenn F

2018-04-21

Heteropteran insects such as assassin bugs (Reduviidae) and giant water bugs (Belostomatidae) descended from a common predaceous and venomous ancestor, and the majority of extant heteropterans retain this trophic strategy. Some heteropterans have transitioned to feeding on vertebrate blood (such as the kissing bugs, Triatominae; and bed bugs, Cimicidae) while others have reverted to feeding on plants (most Pentatomomorpha). However, with the exception of saliva used by kissing bugs to facilitate blood-feeding, little is known about heteropteran venoms compared to the venoms of spiders, scorpions and snakes. One obstacle to the characterization of heteropteran venom toxins is the structure and function of the venom/labial glands, which are both morphologically complex and perform multiple biological roles (defense, prey capture, and extra-oral digestion). In this article, we describe three methods we have successfully used to collect heteropteran venoms. First, we present electrostimulation as a convenient way to collect venom that is often lethal when injected into prey animals, and which obviates contamination by glandular tissue. Second, we show that gentle harassment of animals is sufficient to produce venom extrusion from the proboscis and/or venom spitting in some groups of heteropterans. Third, we describe methods to harvest venom toxins by dissection of anaesthetized animals to obtain the venom glands. This method is complementary to other methods, as it may allow harvesting of toxins from taxa in which electrostimulation and harassment are ineffective. These protocols will enable researchers to harvest toxins from heteropteran insects for structure-function characterization and possible applications in medicine and agriculture.

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.

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

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

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

2018-05-04

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.

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

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Villacís, Anita G; Arcos-Terán, Laura; Grijalva, Mario J

2008-11-01

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 Ecuador and Northern Peru.

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.

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.

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.

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.

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

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.

Estudo anatômico e morfométrico dos folículos testiculares de algumas espécies de Triatominae (Hemiptera: Reduviidae Anatomic and morphometric studies of testicular follicles of some species of Triatominae

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Teresa Cristina M. Gonçalves

1987-12-01

Full Text Available Os folículos testiculares nas ordens dos insetos, vêm demonstrando papel relevante sob o ponto de vista da Sistemática e Filogenia. Nos triatomíneos, os folículos testiculares são em número de sete, sendo que o comprimento e a espesura variam consideravelmente entre os gêneros, e pouco entre as espécies. Verificou-se que em Rhodnius spp existem dois folículos longos e grossos e cinco curtos e fuinnos; em Triatoma spp existem dois longos e finos, dois médios e grossos e três curtos e finos; e em Panstrongylus spp existem sete aproximadamente iguais. Através das medições do comprimento dessas estruturas, evidenciou-se que os valores das médias e desvios padrão das médias, foram muito próximos entre as espécies do mesmo gênero, tornando-se inviável estabelecer limites que pudessem caracterizá-las. Em busca de resultados mais precisos, fizeram-se comparações interespecíficas através da análise de variância: entre as diferentes espécies do mesmo gênro (comparação simultânea; entre cada duas espécies do mesmo gênro (comparação aos pares; e entre espécies iguais de procedência diferentes. Os resultados obtidos não demostraram possibilidades de utilização na Sistemática, contudo foram promissores no que concerne à Filogenia, desde que seja observado um número maior de espécies.The testicular follicle in the varous insect orders, has given evidence of relevance from the point of view of Systematics ans Phylogeny. In the triatomines, the testicular follicles are in number of seven, their lenght and thickness ranging considerabley between the genera and with less variation between the species. It was observed that in Rhodnius spp there exist two long and thick follicles and five short and thin; in Triatoma spp there extist two long and thick, two medium and thick and three short and thin; and in Panstrongylus spp seven, almost identical. Through the measurements of length of these structures, it was observed that the medium value of the averages and the standard deviation of the averages were very close, between the species of the same genus, consequently it was impossible to establish limits characterizing the species. Seecking precise results, interspecific comparisons were made through analysis of variance, as follows: - between different species of the same genus (simultaneous comparison; - between every two species of the same genus (couple comparison; - between identical species of different origin. The results didn't demonstrate the possibility of using this character in Systematics, although they seem to be promising as regards Phylogeny, provided that a great number of species is observed.

Optimization of random amplified polymorphic DNA techniques for use in genetic studies of Cuban triatominae Optimización de la técnica de ADN polimórfico amplificado al azar (RAPD para su utilización en la caracterización genética de triatomíneos cubanos

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Jorge Fraga

2005-10-01

Full Text Available Random amplified polymorphic DNA (RAPD technique is a simple and reliable method to detect DNA polymorphism. Several factors can affect the amplification profiles, thereby causing false bands and non-reproducibility of assay. In this study, we analyzed the effect of changing the concentration of primer, magnesium chloride, template DNA and Taq DNA polymerase with the objective of determining their optimum concentration for the standardization of RAPD technique for genetic studies of Cuban Triatominae. Reproducible amplification patterns were obtained using 5 pmoL of primer, 2.5 mM of MgCl2, 25 ng of template DNA and 2 U of Taq DNA polymerase in 25 µL of the reaction. A panel of five random primers was used to evaluate the genetic variability of T. flavida. Three of these (OPA-1, OPA-2 and OPA-4 generated reproducible and distinguishable fingerprinting patterns of Triatominae. Numerical analysis of 52 RAPD amplified bands generated for all five primers was carried out with unweighted pair group method analysis (UPGMA. Jaccard's Similarity Coefficient data were used to construct a dendrogram. Two groups could be distinguished by RAPD data and these groups coincided with geographic origin, i.e. the populations captured in areas from east and west of Guanahacabibes, Pinar del Río. T. flavida present low interpopulation variability that could result in greater susceptibility to pesticides in control programs. The RAPD protocol and the selected primers are useful for molecular characterization of Cuban Triatominae.La técnica de ADN polimórfico amplificado al azar (RAPD es un método simple para detectar el polimorfismo genético del ADN. Diferentes factores afectan los perfiles de amplificación lo que se manifiesta en la presencia de bandas falsas y en la reproducibilidad del ensayo. En nuestro trabajo analizamos los cambios de la concentración de cebador, ADN molde, cloruro de magnesio y de Taq ADN polimerasa con el objetivo de determinar su

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.

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

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.

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.

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.

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.

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%.

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.

Influence of weather variables and plant communities on grasshopper density in the Southern Pampas, Argentina.

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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

Contribución al estudio de los triatominos del Perú: Distribución geográfica, nomenclatura y notas taxonómicas

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Julio Chávez

2006-03-01

Full Text Available Objetivos: Determinar el número de especies válidas, distribución geográfica, sinonimias, nomenclatura y comentarios taxonómicos de la subfamilia Triatominae. Materiales y Métodos: Se compiló la lista de nombres científicos y distribución geográfica de triatominos existentes en el Perú en las referencias bibliográficas presentadas. Resultados: Existen 18 especies de la subfamilia Triatominae en el Perú distribuidos en 23 departamentos; todas ellas agrupadas en 4 principales tribus y 8 géneros. Conclusiones: Es necesario realizar estudios sobre ecología, morfología, biología molecular y epidemiología para una identificación precisa de especies de triatominos que existen en Perú.

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.

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

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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

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

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Zhang, Guanyang; Hart, Elwood R; Weirauch, Christiane

2016-01-01

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. and Zelus

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.

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.

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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Santos, Claudiney Biral dos; Ferreira, Adelson Luiz; Leite, Gustavo Rocha; Ferreira, Gabriel Eduardo Melim; Rodrigues, Andressa Alencastre Fuzari; Falqueto, Aloísio

2005-01-01

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 Es...

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

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.

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.

Novel adipokinetic hormones in the kissing bugs Rhodnius prolixus, Triatoma infestans, Dipetalogaster maxima and Panstrongylus megistrus

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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

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.

Estudos anatômicos e histológicos sôbre a subfamília Triatominae (Heteroptera, Reduviidae: Parte XXII. A estrutura da córnea de Triatoma Infestans

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Rudolf Barth

1965-01-01

Full Text Available Descreve-se a composição da córnea do ôlho de Triatoma infestans, chegando-se aos seguintes resultados: 1 - A faceta de um omatídeo consta de uma lente quitinosa central, incluída dentro de um prima hexagonal cuticular que, em virtude da sua construção, contribui decisivamente para o isolamento ótico da lente. 2 - A lente é formada (1 pela epicutícula superficial, muito fina, (2 pela exocutícula quase homogênea e (3 pela endocutícula lamelada. A exocutícula apresenta-se em forma de uma lente coletora, sem qualquer pigmento. A endocutícula, também sem pigmentos, compõe-se de numerosas (50 a 80 lamelas cuticulares, em forma de cones encaixados, um no outro, de modo que as extremidades dos cones se encontram no eixo ótico da lente. A lente corresponde à um cristal monaxial. 3 - A córnea é a continuação da cutícula da cabeça; as camadas desta, compostas de tiras quitinosas, coladas por proteínas entre si, desintegram0se em numerosas lamelas. 4 - As propriedades óticas das lentes correspondem às de um cilindro de lentes no sentido de EXNER (1891. 5 - Os omatídeos centrais do ôlho são homocêntrico, os periféricos heterocêntricos com eixo ótico curvado.

Epidemiology of Chagas disease in Ecuador. A brief review

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Aguilar V H Marcelo

1999-01-01

Full Text Available Chagas disease is a complex public health problem that has been underestimated in Ecuador. Here we review the relevant published information, and present unpublished and new data that help to understand the current Chagas disease epidemiological situation and its evolution in the country. Three main characteristics have been identified: (i persistence of Trypanosoma cruzi transmission in already known foci; (ii a marked endemicity in some urban areas of Guayaquil; and (iii the transformation of new Amazon foci into truly endemic areas. The situation in other suspect areas remains uncertain. Five Triatominae species have been implicated in the transmission of T. cruzi to people in Ecuador (Triatoma dimidiata, Rhodnius ecuadoriensis, R. pictipes, R. robustus and Panstrongylus geniculatus, but some others may also play a role in some areas (P. rufotuberculatus, P. howardi, T. carrioni and P. chinai. Other Triatominae reported seem to have little or no epidemiological relevance (T. venosa, T. dispar, Eratyrus mucronatus, E. cuspidatus, P. lignarius and Cavernicola pilosa. High frequency of acute cases and severe chronic disease has been observed. Although cardiomyopathy is more frequent, serious digestive disease is also present. It is estimated that around 120,000-200,000 people may be infected. 2.2 to 3.8 million people are estimated to live under transmission risk conditions.

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 ...

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

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.

Rhodnius prolixus supergene families of enzymes potentially associated with insecticide resistance.

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Schama, Renata; Pedrini, Nicolás; Juárez, M Patricia; Nelson, David R; Torres, André Q; Valle, Denise; Mesquita, Rafael D

2016-02-01

Chagas disease or American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi. Once known as an endemic health problem of poor rural populations in Latin American countries, it has now spread worldwide. The parasite is transmitted by triatomine bugs, of which Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae) is one of the vectors and a model organism. This species occurs mainly in Central and South American countries where the disease is endemic. Disease prevention focuses on vector control programs that, in general, rely intensely on insecticide use. However, the massive use of chemical insecticides can lead to resistance. One of the major mechanisms is known as metabolic resistance that is associated with an increase in the expression or activity of detoxification genes. Three of the enzyme families that are involved in this process - carboxylesterases (CCE), glutathione s-transferases (GST) and cytochrome P450s (CYP) - are analyzed in the R. prolixus genome. A similar set of detoxification genes to those of the Hemipteran Acyrthosiphon pisum but smaller than in most dipteran species was found in R. prolixus genome. All major CCE classes (43 genes found) are present but the pheromone/hormone processing class had fewer genes than usual. One main expansion was detected on the detoxification/dietary class. The phosphotriesterase family, recently associated with insecticide resistance, was also represented with one gene. One microsomal GST gene was found and the cytosolic GST gene count (14 genes) is extremely low when compared to the other hemipteran species with sequenced genomes. However, this is similar to Apis mellifera, a species known for its deficit in detoxification genes. In R. prolixus 88 CYP genes were found, with representatives in the four clans (CYP2, CYP3, CYP4 and mitochondrial) usually found in insects. R. prolixus seems to have smaller species-specific expansions of CYP genes than

Molecular Techniques for Dicistrovirus Detection without RNA Extraction or Purification

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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.

The hemocytes of Panstrogyllus Megistus (Hemiptera: Reduviidae Os hemócitos de Panstrongylus megistus (Hemiptera: Reduviidae

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Margherita Anna Barracco

1987-09-01

Full Text Available Five hemocyte types were identified in the hemolymph of Panstrongylus megistus by phase contrast and common light microscopy using some histochemical methods. These are: Prohemocytes, small cells presenting a great nucleus/cytoplasm ratio; Plasmatocytes, the most numerous hemocytes, are polymorphic cells mainly characterized by a large amount of lysosomes; Granulocytes, hemocytes very similar to plasmatocytes which contain cytoplasmic granules and are especially rich in polysaccharides; Oenocytoids, cells presenting a small nucleus and a thick cytoplasm; they show many small round vacuoles when observed in Giemsa smears and many cytoplasmic granules under phase microscopy; Adipohemocytes, very large hemocytes, presenting many fat droplet inclusions which could correspond to free fat bodies which entered the hemolymph. Only prohemocytes and plasmatocytes can be clearly classified; all the other hemocyte types have a more ambiguous classification.Cinco tipos de hemócitos foram identificados na hemolinfa de Panstrongylus megistus através da microscopia de constraste de fase e de luz, usando alguns testes histoquímicos: Pró-hemócitos-células pequenas que mostram uma grande relação núcleocitoplasmática; Plasmotócitos-células polimporficas, que se caracterizam principalmente pela sua grande abundância em lisossomos - são os hemócitos mais numerosos; Granulócitos-células muito semelhantes aos plasmatócitos que contêm grânulos citoplasmáticos particularmente ricos em polissacarídeos; Enocitóides-hemócitos que apresentam um núcleo pequeno e cujo citoplasma basofílico revela-se muito denso e homogênio - mostram uma série de pequenos vacúolos esféricos quando observados nos esfregaços corados pelo Giemsa, mas a microscopia de fase revela uma grande quantidade de pequenos grânulo ao invés de vacúolos; Adipo-hemócitos-hemócitos muito grandes que contêm uma grande quantidade de inclusões lípicas - poderiam corresponder a células do corpo gorduroso que, destacando-se, penetram na hemolinfa. Somente os p´r-hemócitos e os plasmatócitos podem ser classificados com precisão; os outros tipos podem gerar ambiguidade de classificação.

Tagging of Panstrongylus megistus (Hemiptera, Triatominae) with radioisotopes

International Nuclear Information System (INIS)

Neves, D.P.; Paulini, E.; Ferreira, V.M.

1982-01-01

Experiments have been made in laboratory and field conditions with Panstrongylus megistus, which were tagged by attaching pieces of Ir-192 wire to the pronotum. Marked bugs were detected by a Geiger-Muller counter and were also recaptured in Gomes-Nunez boxes. Bugs were found to cover distances of up to 150 meters in 12 days after release and circulated from sylvatic to domiciliary environments. (M.A.C.) [pt

[Anatomy and histology of salivary glands of Triatominae].

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Lacombe, D

1999-01-01

Histological studies upon the salivary glands of ten species of triatomine bugs were performed looking for their number and structural organization in different genera. It was possible to evaluate the celular epithelium type of each gland, as well as the merocrine and apocrine secretions of the glands. Secretion run until the hilo and after to salivary pump and hypofaringe. The glandular components, D1, D2 and D3 are always present in the Triatoma, Panstrongylus and Diptelogaster but in Rhodnius there are only the first two pairs of glands. The salivary channels and the hilo are analyzed by histology. The whole pair D3 has a clear valve that regularizes the exit of the secretions to the hilo. According to the genus the valves appear in different locations. They have low and dense epithelium, and their nucleus are rich in chromatin. The secondary channels leaving these valves, are very different, with clear chitinous ringer, low level of chromatin in the nucleus and homogeneous cytoplasm.

Encuesta sobre artropodos de interés médico en La Guajira, Colombia, Suramérica

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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.

Observations on the Domestic Ecology of Rhodnius ecuadoriensis (Triatominae

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Abad-Franch F

2002-01-01

Full Text Available Rhodnius ecuadoriensis infests peridomiciles and colonises houses in rural southern Ecuador. Six out of 84 dwellings (7% surveyed in a rural village were infested (78 bugs/infested domicile; 279 bugs were collected in a single dwelling. Precipitin tests revealed R. ecuadoriensis fed on birds (65%, rodents (31%, marsupials (8%, and humans (15% - mixed bloodmeals detected in 37.5% of individual samples. Trypanosoma cruzi from opossums and rodents may thus be introduced into the domestic cycle. Wasp parasitoidism was detected in 6.5% of 995 R. ecuadoriensis eggs (only in peridomestic habitats. Control strategies should integrate insecticide spraying (indoors and peridomestic, better management of poultry, and housing improvements. A possible inefficacy of Malathion is reported.

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.

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.

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

Compositional and mutational rate heterogeneity in mitochondrial genomes and its effect on the phylogenetic inferences of Cimicomorpha (Hemiptera: Heteroptera).

Science.gov (United States)

Yang, Huanhuan; Li, Teng; Dang, Kai; Bu, Wenjun

2018-04-18

Mitochondrial genome (mt-genome) data can potentially return artefactual relationships in the higher-level phylogenetic inference of insects due to the biases of accelerated substitution rates and compositional heterogeneity. Previous studies based on mt-genome data alone showed a paraphyly of Cimicomorpha (Insecta, Hemiptera) due to the positions of the families Tingidae and Reduviidae rather than the monophyly that was supported based on morphological characters, morphological and molecular combined data and large scale molecular datasets. Various strategies have been proposed to ameliorate the effects of potential mt-genome biases, including dense taxon sampling, removal of third codon positions or purine-pyrimidine coding and the use of site-heterogeneous models. In this study, we sequenced the mt-genomes of five additional Tingidae species and discussed the compositional and mutational rate heterogeneity in mt-genomes and its effect on the phylogenetic inferences of Cimicomorpha by implementing the bias-reduction strategies mentioned above. Heterogeneity in nucleotide composition and mutational biases were found in mt protein-coding genes, and the third codon exhibited high levels of saturation. Dense taxon sampling of Tingidae and Reduviidae and the other common strategies mentioned above were insufficient to recover the monophyly of the well-established group Cimicomorpha. When the sites with weak phylogenetic signals in the dataset were removed, the remaining dataset of mt-genomes can support the monophyly of Cimicomorpha; this support demonstrates that mt-genomes possess strong phylogenetic signals for the inference of higher-level phylogeny of this group. Comparison of the ratio of the removal of amino acids for each PCG showed that ATP8 has the highest ratio while CO1 has the lowest. This pattern is largely congruent with the evolutionary rate of 13 PCGs that ATP8 represents the highest evolutionary rate, whereas CO1 appears to be the lowest. Notably

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.

Hallazgo de Trypanosoma Cruzi en momias de más de 4000 años de antigüedad

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Carlos Jaramillo

2000-08-01

Full Text Available

Se presentan los antecedentes de la presencia de triatominos domiciliados en Colombia desde la primera publicación hecha por el doctor César Uribe en 1929 (Editorial Minerva, Bogotá donde se consigna el hallazgo de Trypanosoma cruzi y Trypanosoma rangeli en 15 ejemplares de Rhodnius prolixus provenientes de Prado, Tolima. A continuación se analizan las demás publicaciones en orden cronológico. Informe del Profesor Emile Brumpt (Revista de Higiene, año XX – Números 11 y 12, 1939, Distribución de los Triatominos en Colombia, Hernando Ucrós, Hernando Rocha, Marcos Duque (Antioquia Médica Vol. 21 – 1971 No. 8; Distribution of Triatomine – transmitted trypanosomamiasis in Colombia and vew records of the bugs and infections. A. D’Alessandro, Pablo Barreto and C. A. Duarte R. (1972, J. Med. Ent. Vol. 8, No. 2: 159-172; Colombian Triatominae and their infestation with Trypanosomatid Flagellates. Marinkelle Cornelis J. (1972 Mitt Inst. – Aleman Invest. Cient. 6:13-29; Nuevos registros de triatominos domiciliarios y extradomiciliarios en Colombia. Antonio D’Alessandro, Pablo Barreto y Mauricio Thomas. Colombia Médica Vol. 12 No. 2 – 1981.

Basándose en la anterior información se llega a la conclusión de que los Triatominae domiciliados en Colombia se encuentran en poblaciones situadas sobre los 2.000msnm, principalmente en las zonas central y oriental del país.

El Instituto Nacional de Salud en el año de 1990, como una primera etapa para tratar de determinar la magnitud del problema de la tripanosomiasis americana en Colombia, realizó una investigación para establecer la verdadera distribución de los triatominos domiciliarios en el país.

El estudio se hizo usando el sistema de muestreo, en una muestra estadísticamente representativa. Se inspeccionaron las viviendas de las zonas rurales; se capturaron triatominos vectores que, posteriormente, fueron examinados sistemáticamente en búsqueda de

Distribución de Triatomíneos domiciliados en Colombia.

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Augusto Corredor Arjona

2000-08-01

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Se presentan los antecedentes de la presencia de triatominos domiciliados en Colombia desde la primera publicación hecha por el doctor César Uribe en 1929 (Editorial Minerva, Bogotá donde se consigna el hallazgo de Trypanosoma cruzi y Trypanosoma rangeli en 15 ejemplares de Rhodnius prolixus provenientes de Prado, Tolima. A continuación se analizan las demás publicaciones en orden cronológico. Informe del Profesor Emile Brumpt (Revista de Higiene, año XX – Números 11 y 12, 1939, Distribución de los Triatominos en Colombia, Hernando Ucrós, Hernando Rocha, Marcos Duque (Antioquia Médica Vol. 21 – 1971 No. 8; Distribution of Triatomine – transmitted trypanosomamiasis in Colombia and vew records of the bugs and infections. A. D’Alessandro, Pablo Barreto and C. A. Duarte R. (1972, J. Med. Ent. Vol. 8, No. 2: 159-172; Colombian Triatominae and their infestation with Trypanosomatid Flagellates. Marinkelle Cornelis J. (1972 Mitt Inst. – Aleman Invest. Cient. 6:13-29; Nuevos registros de triatominos domiciliarios y extradomiciliarios en Colombia. Antonio D’Alessandro, Pablo Barreto y Mauricio Thomas. Colombia Médica Vol. 12 No. 2 – 1981.

Basándose en la anterior información se llega a la conclusión de que los Triatominae domiciliados en Colombia se encuentran en poblaciones situadas sobre los 2.000msnm, principalmente en las zonas central y oriental del país.

El Instituto Nacional de Salud en el año de 1990, como una primera etapa para tratar de determinar la magnitud del problema de la tripanosomiasis americana en Colombia, realizó una investigación para establecer la verdadera distribución de los triatominos domiciliarios en el país.

El estudio se hizo usando el sistema de muestreo, en una muestra estadísticamente representativa. Se inspeccionaron las viviendas de las zonas rurales; se capturaron triatominos vectores que, posteriormente, fueron examinados sistemáticamente en búsqueda de

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.

Lysophosphatidylcholine: A Novel Modulator of Trypanosoma cruzi Transmission

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Mário A. C. Silva-Neto

2012-01-01

Full Text Available Lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. Such molecule is also present in saliva and feces of the hematophagous organism Rhodnius prolixus, a triatominae bug vector of Chagas disease. We have recently demonstrated that LPC is a modulator of Trypanosoma cruzi transmission. It acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite, which will provide a concentrated population of cells available for parasite infection. Also, LPC increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion. Finally, LPC inhibits NO production by macrophages stimulated by live T. cruzi, and thus interferes with the immune system of the vertebrate host. In the present paper, we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of Chagas disease.

Automated identification of insect vectors of Chagas disease in Brazil and Mexico: the Virtual Vector Lab

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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.

Lysophosphatidylcholine: A Novel Modulator of Trypanosoma cruzi Transmission

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Silva-Neto, Mário A. C.; Carneiro, Alan B.; Silva-Cardoso, Livia; Atella, Georgia C.

2012-01-01

Lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. Such molecule is also present in saliva and feces of the hematophagous organism Rhodnius prolixus, a triatominae bug vector of Chagas disease. We have recently demonstrated that LPC is a modulator of Trypanosoma cruzi transmission. It acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite, which will provide a concentrated population of cells available for parasite infection. Also, LPC increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion. Finally, LPC inhibits NO production by macrophages stimulated by live T. cruzi, and thus interferes with the immune system of the vertebrate host. In the present paper, we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of Chagas disease. PMID:22132309

DataTri, a database of American triatomine species occurrence

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Ceccarelli, Soledad; Balsalobre, Agustín; Medone, Paula; Cano, María Eugenia; Gurgel Gonçalves, Rodrigo; Feliciangeli, Dora; Vezzani, Darío; Wisnivesky-Colli, Cristina; Gorla, David E.; Marti, Gerardo A.; Rabinovich, Jorge E.

2018-04-01

Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted to mammals - including humans - by insect vectors of the subfamily Triatominae. We present the results of a compilation of triatomine occurrence and complementary ecological data that represents the most complete, integrated and updated database (DataTri) available on triatomine species at a continental scale. This database was assembled by collecting the records of triatomine species published from 1904 to 2017, spanning all American countries with triatomine presence. A total of 21815 georeferenced records were obtained from published literature, personal fieldwork and data provided by colleagues. The data compiled includes 24 American countries, 14 genera and 135 species. From a taxonomic perspective, 67.33% of the records correspond to the genus Triatoma, 20.81% to Panstrongylus, 9.01% to Rhodnius and the remaining 2.85% are distributed among the other 11 triatomine genera. We encourage using DataTri information in various areas, especially to improve knowledge of the geographical distribution of triatomine species and its variations in time.

Diversidad y distribución de acridios (Orthoptera: Acridoidea en pastizales del sur de la región pampeana, Argentina

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Yanina Mariottini

2013-03-01

Full Text Available Los acridios son componentes nativos de los pastizales, dichos sistemas han sido modificados debido a la intensificación de las actividades agrícola-ganaderas y por lo tanto se considera importante estudiar las comunidades de acridios asociadas. Se estudió la diversidad y distribución de acridios en el Sur de la región pampeana a través de muestreos realizados en las comunidades vegetales más representativas del partido de Laprida, provincia de Buenos Aires, durante cinco temporadas (2005-2010. Se recolectaron 22 especies. La subfamilia Melanoplinae fue la más diversa (ocho especies. La mayor cantidad de especies se observó en los pastizales nativos (18. La diversidad en los pastizales alterados (1.75±0.096 fue superior (p<0.05 a la de los pastizales halófilos (1.34±0.12. La riqueza de plantas en los pastizales nativos y los pastizales alterados fue superior (p<0.05 a la de las demás comunidades. Se registro una relación positiva entre la riqueza de plantas y las variables riqueza y diversidad de acridios. La similitud entre las comunidades de acridios estimada por los índices cualitativos fue superior al 60%. En general, las especies que tuvieron una mayor frecuencia de aparición, mostraron una mayor abundancia y distribución. Covasacris pallidinota, Dichroplus elongatus, D. maculipennis, Borellia bruneri y B. pallida fueron las de mayor distribución, cinco especies tuvieron una distribución intermedia y la mayoría (12 una distribución restringida.

Ecological aspects of a Cosmopolites sordidus (Germar (Coleoptera: Curculionidae population in São Miguel do Iguaçu, PR./ Aspectos ecológicos da população de Cosmopolites sordidus, (Germar (Coleoptera: Curculionidae em São Miguel do Iguaçu, PR

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Cristiane Rohde

2006-06-01

Full Text Available The population dynamics of Cosmopolites sordidus (Germar was studied in banana crops (cultivar Nanicão at São Miguel do Iguaçu, PR, using roof-tile-like baits, between June/2003 and May/2004. Adults infected by entomopathogenic fungi were recorded, and predators were also found on the baits. A comparative bioassay was carried out between the Beauveria bassiana isolate obtained from the experiment area and from other regions in Brazil against C. sordidus adults. The population peaks of C. sordidus adults occurred in June and July, a period with mild temperatures and low precipitation. The population of C. sordidus larvae, however, was concentrated in December. The insect predators found in the area were insects of the following orders: Coleoptera (Carabidae, Dermaptera (Forficulidae, Hemiptera (Reduviidae, Hymenoptera (Formicidae, and spiders of the families Ctenidae, Clubionidae, and Lycosidae, with a population peak two months after the pest population peak. A low number of C. sordidus adults infected by B. bassiana was found, with an annual mean of 0.44%. In the laboratory, the B. bassiana isolates were pathogenic to the insects.Estudou-se a dinâmica populacional de Cosmopolites sordidus (Germar em cultivo de banana(cultivar Nanicão, em São Miguel do Iguaçu, PR, através de iscas do tipo telha, entre junho/2003 a maio/2004. Atribuiu-se conceito ao estado de conservação da isca, visando observar sua durabilidade e atratividade. Registraram-se adultos infectados por fungos entomopatogênicos, sendo também encontrados predadores nas iscas. Realizou-se um bioensaio com isolados de Beauveria bassiana da área experimental e de Centros de Pesquisa do Brasil, para avaliar a patogenicidade em C. sordidus. Verificou-se que os picos populacionais de adultos de C. sordidus ocorreram em junho e julho, período de temperaturas amenas e baixas precipitações, enquanto que as larvas foram mais abundantes em dezembro. Os insetos predadores

Ocorrência de Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986(Hemiptera: Homoptera, Psyllidae em plantios experimentais de camu-camu Myrciaria dubia (H.B.K. Mc Vaugh em Manaus (Amazonas, Brasil Occurrence of Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986 (Hemiptera: Homoptera, Psyllidae in experimental plantations of camu-camu Myrciaria dubia (H.B.K. Mc Vaugh in Manaus (Amazonas, Brazil

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Márcio Luís Leitão Barbosa

2004-01-01

Full Text Available O cultivo de camu-camu Myrciaria dubia (H.B.K. Mc Vaugh tem apresentado inúmeros problemas fitossanitários, dentre os quais, Tuthillia cognata Hodkinson et al. (Hemiptera: Homoptera, Psyllidae, que constantemente é citada como praga secundária. Os objetivos deste estudo foram determinar o nível e a intensidade de infestação (% por T. cognata e estudar aspectos do ciclo biológico e do comportamento de T. cognata, em plantios experimentais de camu-camu. Foram selecionados, de forma aleatória, 17 e 14 exemplares nos plantios I e II, respectivamente. Para cada uma das variáveis estudadas, foram calculados a média aritmética, o desviopadrão, a variância e a amplitude de variação. Foi verificado um nível de infestação de 82% (plantio I e 57% (plantio II, uma intensidade de infestação de 94% (plantio I e 75% (plantio II e uma média de seis ninfas/folha em cada plantio, o que indica que T. cognata representa uma das pragas-chave dessa cultura. Foram observados adultos de Chrysoperla sp. (Neuroptera: Chrysopidae e ninfas de Reduviidae (Hemiptera: Heteroptera, que podem atuar como prováveis agentes de controle biológico de T. cognata.The cultivation of camu-camu Myrciaria dubia (H.B.K. Mc Vaugh has presented countless phytosanitary problems, among them, Tuthillia cognata Hodkinson et al. (Hemiptera: Homoptera, Psyllidae, which often is noticed as a secondary pest. This study aimed to determine the level and the intensity of infestation (% for T. cognata, as well as to study the biological cycle and behavioural aspects of T. cognata, in experimental plantation of camu-camu. 17 and 14 specimens from plantation I and II, respectively, were randomly selected. The arithmetic average, the standard deviation, the variance and the total amplitude were calculated for each studied variable. A level of infestation of 82% (plantation I and 57% (plantation II, an intensity of infestation of 94% (plantation I and 75% (plantation II and an

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.

Phylogeny and character evolution in the bee-assassins (Insecta: Heteroptera: Reduviidae).

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Forero, D; Berniker, L; Weirauch, C

2013-01-01

Apiomerus, the charismatic bee-assassins (>108 spp.), belong to the New World resin bugs in the harpactorine tribe Apiomerini (12 extant genera) that is characterized by a novel predation strategy, resin trap predation. Apiomerini also exhibit striking genitalic diversity that has shaped subgeneric classifications within the genus Apiomerus and females of some species of Apiomerus are known to engage in unique maternal care behaviors. The lack of a phylogenetic framework currently hinders evolutionary interpretations of genitalic morphology and maternal care. We here present a molecular phylogeny based on 4, 477 bp of six ribosomal and protein coding genes and 95 terminal taxa using parsimony and maximum likelihood approaches as a way of addressing these shortcomings. Apiomerini are monophyletic, with Heniartes being the sistergroup to all remaining taxa that form the monophyletic Manicocoris (Calliclopius, Manicocoris, Micrauchenus, and Ponerobia) and Apiomerus (Agriocoris, Apiomerus, and Sphodrolestes) clades. Previously proposed subgeneric groups are polyphyletic, but several proposed species groups are recovered as monophyletic. Ancestral state reconstruction of the metatibial comb indicates that this structure evolved in the ancestor of all Apiomerini where it was present in males and in females; it became strongly sexually dimorphic (better developed in females than in males) in the Apiomerus clade (Apiomerus + Agriocoris + Sphodrolestes). Genitalic features reveal a pattern of homoplasy, but frequently are nonetheless useful to diagnose supraspecific groups within Apiomerus. The complex genitalia found within Apiomerus are derived for that clade. We conclude that, using the metatibial comb as a proxy, maternal care is relatively common in the tribe Apiomerini and propose that it likely evolved at the base of the Apiomerus clade if not at the base of Apiomerini. Copyright © 2012 Elsevier Inc. All rights reserved.

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

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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.

Area-wide control of Chagas disease vectors in Latin America

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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

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.

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.

Jaburetox-induced toxic effects on the hemocytes of Rhodnius prolixus (Hemiptera: Reduviidae).

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Moyetta, Natalia R; Broll, Valquiria; Perin, Ana Paula A; Uberti, Augusto F; Coste Grahl, Matheus V; Staniscuaski, Fernanda; Carlini, Celia R; Fruttero, Leonardo L

2017-10-01

Jaburetox is a recombinant peptide derived from a Canavalia ensiformis urease that presents toxic effects upon several species of insects, phytopathogenic fungi and yeasts of medical importance. So far, no toxicity of Jaburetox to mammals has been shown. Previous reports have identified biochemical targets of this toxic peptide in insect models, although its mechanism of action is not completely understood. In this work, we aimed to characterize the effects of Jaburetox in hemolymphatic insect cells. For this purpose, the model insect and Chagas' disease vector Rhodnius prolixus was used. In vivo and in vitro experiments indicated that Jaburetox interacts with a subset of hemocytes and it can be found in various subcellular compartments. In insects injected with Jaburetox there was an increase in the gene expression of the enzymes UDP-N-acetylglucosamine pyrophosphorylase (UAP), chitin synthase and nitric oxide synthase (NOS). Nevertheless, the expression of NOS protein, the enzyme activities of UAP and acid phosphatase (a possible link between UAP and NOS) as well as the phosphorylation state of proteins remained unchanged upon the in vivo Jaburetox treatment. Nitric oxide (NO) imaging using fluorescent probes showed that Jaburetox augmented NO production in the hemocyte aggregates when compared to controls. Even though Jaburetox activated the hemocytes, as demonstrated by wheat germ agglutinin binding assays, the peptide did not lead to an increase of their phagocytic behavior. Taken together, these findings contribute to our understanding of toxic effects of Jaburetox, a peptide with biotechnological applications and a prospective tool for rational insect control. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

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.

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.

[Transmission risk of Trypanosoma cruzi in Metztitlán municipality from Hidalgo state, México, by characterization of domiciliary units and their entomologic indexes].

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Becerril, Marco A; Angeles-Pérez, Vidal; Noguez-García, Julio Cr; Imbert-Palafox, José L

2010-01-01

In order to determine the risk of transmission of Trypanosoma cruzi by triatomines in Metztitlan municipality, Hidalgo State, Mexico, entomological indexes were calculated and the characteristics of dwellings were described. A transversal, retrospective, descriptive, and observational study was performed by means of an intentional not probabilistic and expertise sampling from January to December of 2005 in 10 localities in which presence of triatomines were investigated either intra or peridomestic environmental in 699 houses. Building material and presence of infected triatomines with T. cruzi were registered to determine entomologic indexes. The triatomine species collected were: Triatoma barberi (Usinger) and T. mexicana (Herrich-Schaeffer) (Hemiptera: Reduviidae). The results indicated that natural infection index varied from 7.7% to 50%; colonization index reached 80%; infestation index varied from 7.7% to 25%; dispersion index was 70%. Stone-walled houses were more infested. We can conclude that it is necessary to establish T. cruzi transmission control measures against triatomines in localities from Metztitlan, primarily in stone-walled houses where T. barberi occurs, as it was the most important vector species in the transmission of T. cruzi in this municipality.

Estadísticos poblacionales de Triatoma sordida Stäl 1859 (Hemiptera : Reduviidae en condiciones experimentales Population statistics of Triatoma sordida Stäl 1859 (Hemiptera: Reduviidae in experimental conditions

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Elena B. Oscherov

1996-10-01

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.Foram estudados diferentes parâmetros populacionais de Triatoma sordida em condições de laboratório. Realizou-se um seguimento longitudinal de quatro coortes de 100 ovos cada uma; os insetos foram criados a 28°C ± 3°C e 63% ± 10% de umidade relativa, e alimentados cada sete dias sobre galinha (Gallus domesticus durante 40'. As coortes foram controladas uma vez por semana. A expectativa de vida média dos machos foi de 37,4 semanas e a das fêmeas de 36,8.O tempo médio de desenvolvimento foi de 61,7 semanas. A taxa reprodutiva líquida indica que esta população aumentará 143,2 vezes durante cada geração. A taxa intrínseca do crecimento natural foi de 0,082 por semana. A média do valor máximo reprodutivo verificou-se na terceira semana no início do estádio adulto.A distribuição estável de idades de T. sordida seria de 32% ovos, 26% ninfas do primeiro estádio, 19% ninfas do segundo estádio, 13% ninfas do terceiro estádio, 6% ninfas do quarto estádio, 3% ninfas do quinto estádio e 1% de adultos. A análise dos parâmetros permite considerar que esta espécie comporta-se como K-estrategista em condições experimentais.Four cohorts of 100 Triatoma sordida eggs were reared under standard laboratory conditions (28ºC, 63% R.H. and fed weekly on hens during 40 minutes. The numbers of dead insects, moults and eggs laid were recorded weekly. A constant survival value was observed without any important peaks in the four cohorts. Life expectancy was 37.4 weeks for males and 36.8 weeks for females. The average generation time was 61.7 weeks. The average net reproduction rate suggests that this population would increase 143.2 times during each generation. The average intrinsic rate of natural increase was 0.082 per individual per week. The highest reproductive value was observed 3 weeks after entering the adult stage. The age structure, assuming stable age distribution, would be 32% eggs, 26% of first instar nymphs, 19% of second instar nymphs, 13% of third instar nymphs, 6% of fourth instar nymphs, 3% of fifth instar nymphs and 1% of adults. Our results suggest that this species behaves as a k-strategist under experimental conditions.

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.

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

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Neumann, Arthur da Silva; Dias, Felipe de Almeida; Ferreira, Jéssica da Silva; Fontes, Amanda Nogueira Brum; Rosa, Patricia Sammarco; Macedo, Rafael Enrique; Oliveira, José Henrique; Teixeira, Raquel Lima de Figueiredo; Pessolani, Maria Cristina Vidal; Moraes, Milton Ozório; Suffys, Philip Noel; Oliveira, Pedro L; Sorgine, Marcos Henrique Ferreira; Lara, Flavio Alves

2016-01-01

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.

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

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

2003-10-01

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-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.

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

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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-...

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.

A taxonomic revision of the new world species of Sirthenea (Heteroptera: Reduviidae: Peiratinae)

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Willemse, L.

1985-01-01

The American species of Sirthenea are revised and keys to the 12 species and seven subspecies are given. Four new species and two new subspecies are described viz., S. ater (Brazil: Minas Geraes), S. dubia (Panama; Paraguay: Caaguazu. Argentina: Misiones; Entre Rios), S. ferdinandi (Argentina:

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.

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.

[Diversity and distribution of grasshoppers (Orthoptera: Acridoidea) in grasslands of the Southern Pampas region, Argentina].

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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.

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.

Active dispersal of Triatoma infestans and other triatomines in the Argentinean arid Chaco before and after vector control interventions.

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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.

Genetic, cytogenetic and morphological trends in the evolution of the Rhodnius (Triatominae: Rhodniini) trans-Andean group.

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Díaz, Sebastián; Panzera, Francisco; Jaramillo-O, Nicolás; Pérez, Ruben; Fernández, Rosina; Vallejo, Gustavo; Saldaña, Azael; Calzada, Jose E; Triana, Omar; Gómez-Palacio, Andrés

2014-01-01

The Rhodnius Pacific group is composed of three species: Rhodnius pallescens, R. colombiensis and R. ecuadoriensis, which are considered important vectors of trypanosomes (Trypanosoma cruzi and T. rangeli) infecting humans. This group is considered as a recent trans-Andean lineage derived from the widespread distributed sister taxa R. pictipes during the later uplift of northern Andes mountain range. The widest spread species R. pallescens may be a complex of two divergent lineages with different chromosomal attributes and a particular biogeographical distribution across Central America and Colombia with several southern populations in Colombia occupying the same sylvatic habitat as its sister species R. colombiensis. Although the taxonomy of Rhodnius Pacific group has been well studied, the unresolved phylogenetic and systematic issues are the target of this paper. Here we explore the molecular phylogeography of this species group analyzing two mitochondrial (ND4 and cyt b) and one nuclear (D2 region of ribosomal 28S gene) gene sequences. The molecular analyses suggest an early divergence of the species R. ecuadoriensis and R. colombiensis, followed by a recent expansion of R. pallescens lineages. The phylogenetic relationship between sympatric R. pallescens Colombian lineage and R. colombiensis was further explored using wing morphometry, DNA genome size measurements, and by analyzing chromosomal behavior of hybrids progeny obtained from experimental crosses. Our results suggest that the diversification of the two R. pallescens lineages was mainly influenced by biogeographical events such as (i) the emergence of the Panama Isthmus, while the origin and divergence of R. colombiensis was associated with (ii) the development of particular genetic and chromosomal features that act as isolation mechanisms from its sister species R. pallescens (Colombian lineage). These findings provide new insights into the evolution of the Rhodnius Pacific group and the underlying biological processes that occurred during its divergence.

Fauna de insectos hematófagos del sur del Parque Natural Nacional Chiribiquete, Caquetá, Colombia

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Jorge A. Molina

2000-12-01

Full Text Available Como parte del estudio para el manejo y la conservación del Parque Natural Nacional Chiribiquete, desarrollado por la Fundación Puerto Rastrojo, se realizó un inventario de la fauna entomológica hematófaga en la estación biológica de Puerto Abeja (rio Mesay, municipio de Solano, departamento de Caquetá. Se calcularon los índices de similitud de Jaccard y el indice de diversidad de Shannon-Weaver y se determinaron los patrones de picadura de los dipteros diurnos para los seis tipos de bosques evaluados. Se registraron 31 especies de Culicidae, 1 de Triatominae, 1 de Ceratopogonidae, 2 de Simuliidae, 10 de Phlebotominae y 6 de Tabanidae. Se obtuvieron tres nuevos registros de especies de Culicidae para Colombia: Sabethes glaucodaemon, Trichoprosopon espini y Uranotaenia pallidoventer; y se amplió el registro de varios insectos hematófagos en el departamento de Caquetá. Se presentan los patrones de actividad de las especies diurnas y su relación con los tipos de bosque y se sugieren posibles medidas de control para evitar enfermedades transmitidas por diferentes vectores, resaltando la importancia epidemiológica de las especies capturadas que presentan capacidad vectorial.

Comparative Analysis of Repetitive DNA between the Main Vectors of Chagas Disease: Triatoma infestans and Rhodnius prolixus.

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

2018-04-24

Chagas disease or American trypanosomiasis affects six to seven million people worldwide, mostly in Latin America. This disease is transmitted by hematophagous insects known as "kissing bugs" (Hemiptera, Triatominae), with Triatoma infestans and Rhodnius prolixus being the two most important vector species. Despite the fact that both species present the same diploid chromosome number (2 n = 22), they have remarkable differences in their total DNA content, chromosome structure and genome organization. Variations in the DNA genome size are expected to be due to differences in the amount of repetitive DNA sequences. The T. infestans genome-wide analysis revealed the existence of 42 satellite DNA families. BLAST searches of these sequences against the R. prolixus genome assembly revealed that only four of these satellite DNA families are shared between both species, suggesting a great differentiation between the Triatoma and Rhodnius genomes. Fluorescence in situ hybridization (FISH) location of these repetitive DNAs in both species showed that they are dispersed on the euchromatic regions of all autosomes and the X chromosome. Regarding the Y chromosome, these common satellite DNAs are absent in T. infestans but they are present in the R. prolixus Y chromosome. These results support a different origin and/or evolution in the Y chromosome of both species.

Hemi-nested PCR and RFLP methodologies for identifying blood meals of the Chagas disease vector, Triatoma infestans.

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Roellig, Dawn M; Gomez-Puerta, Luis A; Mead, Daniel G; Pinto, Jesus; Ancca-Juarez, Jenny; Calderon, Maritza; Bern, Caryn; Gilman, Robert H; Cama, Vitaliano A

2013-01-01

Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted by hematophagous reduviid bugs within the subfamily Triatominae. These vectors take blood meals from a wide range of hosts, and their feeding behaviors have been used to investigate the ecology and epidemiology of T. cruzi. In this study we describe two PCR-based methodologies that amplify a fragment of the 16S mitochondrial rDNA, aimed to improve the identification of blood meal sources for Triatoma infestans: a.--Sequence analyses of two heminested PCRs that allow the identification of mammalian and avian species, and b.--restriction fragment length polymorphism (RFLP) analysis from the mammalian PCR to identify and differentiate multi-host blood meals. Findings from both methodologies indicate that host DNA could be detected and the host species identified in samples from laboratory reared and field collected triatomines. The implications of this study are two-fold. First, these methods can be used in areas where the fauna diversity and feeding behavior of the triatomines are unknown. Secondly, the RFLP method led to the identification of multi-host DNA from T. infestans gut contents, enhancing the information provided by this assay. These tools are important contributions for ecological and epidemiological studies of vector-borne diseases.

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

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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.

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.

Metabolic Post-feeding Changes in Fat Body and Hemolymph of Dipetalogaster maximus (Hemiptera:Reduviidae

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Lilián E Canavoso

1998-03-01

Full Text Available Lipids and glycogen in fat body as well as the modifications in the wet weight of this organ were evaluated in an unfed insect, Dipetalogaster maximus, on day 5 after adult ecdysis (time 0 and during a 30-day period after ingestion of blood meal. Total lipids, high density lipophorin (HDLp, carbohydrates, total proteins and uric acid were determined in the hemolymph during the same period. Fat body wet weight was maximum on day 10 post-feeding and represented on day 30 only 42% of the maximum weight. Lipids stored in the fat body increased up to day 15 reaching 24% of the total weight of tissue. Glycogen was maximum on day 20, representing approximately 3% of the fat body weight. HDLp represented at all times between 17-24% of the total proteins, whose levels ranged between 35 and 47 mg/ml. Uric acid showed at 20, 25 and 30 days similar levels and significantly higher than the ones shown at days 10 and 15. Hemolymphatic lipids fluctuated during starvation between 3-4.4 mg/ml and carbohydrates showed a maximum on day 15 after a blood meal, decreasing up to 0.26 mg/ml on day 25. The above results suggest that during physiological events such as starvation, the availability of nutrients is affected, involving principally the fat body reserves

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

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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...

Infestation of Palm Trees by Triatomines (Hemiptera: Reduviidae in the State of Bahia, Brazil

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Rodrigo Gurgel-Gonçalves

2012-12-01

Resumo. As palmeiras desempenham papéis importantes como habitats de reprodução e alimentação para triatomíneos silvestres, vetores da doença de Chagas. A ocorrência de triatomíneos em palmeiras peridomiciliares pode aumentar o risco de invasão desses insetos em domicílios e deve ser considerada para desenvolver estratégias de prevenção. Com objetivo de investigar a infestação de palmeiras por triatomíneos no Estado da Bahia e determinar a infecção natural desses insetos por Trypanosoma spp., foram amostradas 183 palmeiras em 12 municípios entre 2006 e 2011 utilizando captura manual e/ou armadilhas adesivas iscadas com camundongos. Os triatomíneos foram detectados em 79 palmeiras (43% das espécies Copernicia prunifera (Mart. Becc., Mauritia flexuosa L. e Attalea spp. (Attalea burretiana Bondar ou Attalea salvadorensis Glassman. Em outras espécies de palmeiras (Syagrus coronata (Mill H.E. Moore, Attalea funifera Mart ex. Spreng e Elaeis guineensis Jacq não foram detectados triatomíneos. Rhodnius neglectus Lent, Triatoma sordida (Stål, e Triatoma pseudomaculata Corrêa & Espínola ocorreram em C. prunifera ao longo do rio São Francisco. No extremo oeste da Bahia, R. neglectus e Psammolestes tertius Lent & Jurberg foram detectados em M. flexuosa, enquanto Triatoma tibiamaculata (Pinto ocorreu em Attalea sp. em áreas urbanas de Salvador. No total, 180 triatomíneos foram capturados, principalmente R. neglectus. A maior taxa de infecção natural (61% foi observada em T. tibiamaculata. Os resultados indicam que pelo menos três espécies de palmeiras são habitats favoráveis para triatomíneos no estado da Bahia e ocorrem no ambiente peridomiciliar, o que pode aumentar a probabilidade de invasão de triatomíneos nas casas.

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.

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.

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

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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

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.

Insects associated with tropical foliage produced in the coffee growing region of Colombia

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Luis F. Aristizábal

2013-09-01

Full Text Available We conducted a survey of insects and pest management practices on 34 farms growing ornamental tropical foliage plants in the central coffee region of Colombia over two years. Tropical foliage provided habitat for a diverse range of insects. In total, phytophagous or detritivorous insects from six orders, 40 families and 62 genera were collected. The most common were Hemiptera (29 genera from 16 families, followed by Coleoptera (17 genera from 4 families, Diptera (5 genera from 5 families, Lepidoptera (5 genera from 4 families, Hymenoptera (3 genera from 2 families and Orthoptera (2 genera from 2 families. The most common phytophagous species were leaf cutting ants (Atta and Acromyrmex spp., leaf beetles (Chrysomelidae, leafhoppers (Cicadellidae, stinkbugs (Pentatomidae, squash bugs (Coreidae, tree hoppers (Membracidae and plant hoppers (Fulgoridae. Beneficial insects identified from tropical foliage included predators and parasitoids amongst 5 orders, 12 families and 22 genera. The most abundant were predators among the Coccinellidae, Chrysopidae, Reduviidae, Lycidae and Formicidae but only low numbers of parasitoids (Ichneumonidae, Braconidae and Tachinidae were collected. A pest management questionnaire given to growers revealed a preponderance of reliance on broad spectrum insecticides with a smaller number of growers (approximately one third also using some biological control methods. Our survey contributes basic information regarding diversity of Neotropical insects associated with ornamental foliage plants.

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

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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.

Histogical and ultrastructural aspects of the brindley's glands of pantrongylus megistus (Burmeister, 1835 (Hemiptera: Reduviidae

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Jacenir Reis dos Santos-Mallet

1990-06-01

Full Text Available The Brindley's glands of Panstrongylus megistus were studied under the antomic, histologic and ultrastructural point of view. These glands located in the insect's methatorax are paired and have an opening near the third parir of the feet. Beside this aperture, ther are evaporation areas. Shape, sixe and aspect of the gland vary according to the feeding status. The glands are composed by a tubular part corresponding to the duct and a sack-like portion corrsponding to the secretory part. By electron microscopy we observed that the basal part of the epithelium has many interdigitations associated with mitochondria. On the apical surface where epicuticular foldings are located an electonlucent space is often seen. The glands are composed of the following elements: 1 superficial epithelial cells, located just below the apical surface foldings; 2 secretory cells; which are long and have an intracellular canalicule which changes according to the functional state of the cell; 3 a collecting duct to the secretory cells and covered with an epicuticle, reaching up to the gland's lumen; and 4 cells around the duct.

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

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.

Differential expression profiles in the midgut of Triatoma infestans infected with Trypanosoma cruzi.

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Diego S Buarque

Full Text Available Chagas disease, or American trypanosomiasis, is a parasitic disease caused by the protozoan Trypanosoma cruzi and is transmitted by insects from the Triatominae subfamily. To identify components involved in the protozoan-vector relationship, we constructed and analyzed cDNA libraries from RNA isolated from the midguts of uninfected and T. cruzi-infected Triatoma infestans, which are major vectors of Chagas disease. We generated approximately 440 high-quality Expressed Sequence Tags (ESTs from each T. infestans midgut cDNA library. The sequences were grouped in 380 clusters, representing an average length of 664.78 base pairs (bp. Many clusters were not classified functionally, representing unknown transcripts. Several transcripts involved in different processes (e.g., detoxification showed differential expression in response to T. cruzi infection. Lysozyme, cathepsin D, a nitrophorin-like protein and a putative 14 kDa protein were significantly upregulated upon infection, whereas thioredoxin reductase was downregulated. In addition, we identified several transcripts related to metabolic processes or immunity with unchanged expressions, including infestin, lipocalins and defensins. We also detected ESTs encoding juvenile hormone binding protein (JHBP, which seems to be involved in insect development and could be a target in control strategies for the vector. This work demonstrates differential gene expression upon T. cruzi infection in the midgut of T. infestans. These data expand the current knowledge regarding vector-parasite interactions for Chagas disease.

Challenges and opportunities for primary, secondary, and tertiary prevention of Chagas' disease.

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Rassi, A; Dias, J C P; Marin-Neto, J A; Rassi, A

2009-04-01

A century after its discovery, Chagas' disease still represents a major public health challenge in Latin America. Moreover, because of growing population movements, an increasing number of cases of imported Chagas' disease have now been detected in non-endemic areas, such as North America and some European countries. This parasitic zoonosis, caused by Trypanosoma cruzi, is transmitted to humans by infected Triatominae insects, or occasionally by non-vectorial mechanisms, such as blood transfusion, mother to fetus, or oral ingestion of materials contaminated with parasites. Following the acute phase of the infection, untreated individuals enter a chronic phase that is initially asymptomatic or clinically unapparent. Usually, a few decades later, 40-50% of patients develop progressive cardiomyopathy and/or motility disturbances of the oesophagus and colon. In the last decades several interventions targeting primary, secondary and tertiary prevention of Chagas' disease have been attempted. While control of both vectorial and blood transfusion transmission of T cruzi (primary prevention) has been successful in many regions of Latin America, early detection and aetiological treatment of asymptomatic subjects with Chagas' disease (secondary prevention) have been largely underutilised. At the same time, in patients with established chronic disease, several pharmacological and non-pharmacological interventions are currently available and have been increasingly used with the intention of preventing or delaying complications of the disease (tertiary prevention). In this review we discuss in detail each of these issues.

The Triatomines of Northern Peru, with Emphasis on the Ecology and Infection by Trypanosomes of Rhodnius ecuadoriensis (Triatominae

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Cuba Cuba César A

2002-01-01

Full Text Available Information on the distribution and synanthropic behaviour of triatomines is essential for Chagas disease vector control. This work summarises such information from northern Peru, and presents new data on Rhodnius ecuadoriensis - an important local vector infesting 10-35% of dwellings in some zones. Three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. Panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the Marañón river system. R. ecuadoriensis and Triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern Peru. Confirmation of this hypothesis would result in a local eradication strategy being recommended. Presence of trypanosome natural infection was assessed in 257 R. ecuadoriensis; Trypanosoma rangeli was detected in 4% of bugs. Six further triatomine species are potential disease vectors in the region (T. carrioni, P. chinai, P. rufotuberculatus, P. geniculatus, R. pictipes, and R. robustus, whilst Eratyrus mucronatus, E. cuspidatus, Cavernicola pilosa, Hermanlentia matsunoi, and Belminus peruvianus have little or no epidemiological significance. A strong community-based entomological surveillance system and collaboration with Ecuadorian public health authorities and researchers are recommended.

Effects of gamma irradiation on the reproductive capacity and the longevity of Panstrongylus megistus (Hemiptera: Reduviidae)

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Vercosa, P.; Falcao, P.H.B.; Furtado, A.F.

1993-01-01

An indirect correlation between longevity and radiation doses was observed. Males were more affected than females. Longevity of females submitted to 10 Gy was not different when compared to controls. Some of the irradiated males copulated and in these cases semen was transferred to females, but only few eggs were laid. Fertility was seriously afected in all irradiated groups, decreasing with increasing intensity of dose. The dose of 80 Gy induced sterility in males and females. Gelations spermatophores that were expelled by females irradiated with 20 and 40 Gy, may be a consequence of irradiation that induced modification in the bursa copulatrix pH. (author). 15 refs, 4 figs, 6 tabs

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

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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.

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.

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.

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae) in State of Ceará, Northeastern Brazil.

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Pessoa, Grasielle Caldas D'Ávila; Trevizani, Nathália Abreu Borges; Dias, Letícia Sena; Bezerra, Claudia Mendonça de; Melo, Bernardino Vaz de; Diotaiut, Liléia

2015-01-01

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. 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. 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%. 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.

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.

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.

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.

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

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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.

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. 

Experimental transmission of Trypanosoma cruzi through the genitalia of albino mice

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Leidi Herrera

2001-07-01

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.

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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Roux, Emmanuel; de Fátima Venâncio, Annamaria; Girres, Jean-François; Romaña, Christine A

2011-11-01

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.

Fauna Triatominae no Estado da Bahia, Brasil: as espécies e distribuição geográfica

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Ítalo A. Shetlock

1972-10-01

Full Text Available Este é a primeira de uma série de publicações sobre os triatomíneos do Estado da Bahia, com base nos dados obtidos na inspeção de 889.972 domicílios de 11.045 localidades do Estado, nos anos de 1957 a 1971, quando se coletaram 33.588 exemplares do hemíptero. Foram identificadas 18 espécies pertencentes a 4 gêneros, conforme a seguir e relatado. Triatoma rubrovária, referida em antiga citação, não mais ocorre no Estado. Triatoma bahiensis perdeu sua validade específica, sendo considerada apenas urna variedade de T. pessoal. Existem também variedades de outras espécies, as quais serão estudadas com mais detalhes noutros trabalhes futuros. Panstrongylus megistus é principalmente abundante na faixa litorânea do Estado, com florestas latifoleadas, onde as condições de umidade são elevadas e oclima, é tropical quente e úmido. É a espécie considerada de maior importância na transmissão da Doença de Chagas na Bahia. T. brasiliensis foi encontrada comumente nas áreas de clima estépico com vegetação xerófila. A sua presença em áreas de clima, tropical quente e úmido, foi traduzida como sendo uma variedade da espécie. O seu encontro em áreas de florestas latifoleadas úmidas com clima de selvas, foi aceito como devido, possivelmente, ao transporte mecânico. Verificou-se que T. infestans, antes limitada ao paralelo 16° nos climas mesotérmicos está se disseminando, provavelmente por ação mecânica para áreas possuidoras de características climáticas diversas. T. sórdida foi encontrada somente nas áreas de clima seco seguindo de uma maneira geral o curso dos rios. T. rubrofasciata permaneceu com sua distribuição limitada a duas cidades coloniais na zona litorânea, rarefazendo-se nestes últimos anos, provavelmente devido a higienização por que passam os locais de sua antiga penetração. O gênero Rhodnius que é representado pelo R. negletus, constou de um só exemplar coletado num domicílio, em zona de clima, estéptico com vegetação xerófila. Do género Psamolestes, foi considerada como a única espécie ocorrente o F. tertius. Esta espécie está disseminada por todo o Estado, dependendo provavelmente a sua distribuição da dos ninhos das aves nos quais colonizam. As seguintes espécies também ocorrem, porém em menor densidade, às vezes sendo representadas por achados fortuitos, e tem limitadas áreas de distribuição no Estado: P. diasi. P. geniculatus, P. lutzi, T. costalimai, T. lenti, T maculata, T. melanocephala, P. pessoai, T. petrochii e T. tíbíamacuiata.

Levantamento entomofaunístico de artrópodes em algodoeiro de fibra naturalmente colorida em Ipanguaçu-RN

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Bárbara Karine de Albuquerque Silva

2016-08-01

Full Text Available Objetivou-se com esta pesquisa identificar a diversidade de artrópodes associados à cultura do algodão Gossypium hirsutum L. com pluma colorida, sendo realizados levantamentos entomofaunístico em Ipanguaçu-RN em áreas de produção. A área experimental foi composta por 15 variedades de algodão com pluma colorida: CNPA 2009-6; CNPA 2009-11; CNPA 2009-13; CNPA 2009-16; CNPA 2009-27; CNPA 2009-42; CNPA 2009-47; CNPA 2009-48; CNPA 2009-50; CNPA 2009-59; CNPA 2009-60; CNPA 2009-62; BRS RUBI; BRS AROEIRA; BRS TOPÁZIO. O levantamento foi realizado tendo como base três métodos de coleta ativa em pontos aleatórios da área experimental. As coletas consistiram da retirada manual de folhas e maçãs diretamente da planta, além da captura de insetos em pleno voo, com auxílio de rede entomológica. Foram encontrados um total 1884 insetos adultos e 66 larvas, dispostos em 8 ordens e 22 famílias. A família Aphididae: Hemiptera foi a mais numerosa entre o material coletado, com 1720 adultos dispersos nos três métodos de coleta aplicados. Além desta, outras famílias de pragas da cultura foram encontradas, como Curculionidae: Coleoptera. Também foram coletados organismos benéficos como os polinizadores Aphidae e Megachilidae, pertencentes a ordem Hymenoptera, predadores (Coccinellidae: Coleoptera; Vespidae: Hymenoptera; Reduviidae: Hemiptera; Chrysopidae: Neuroptera e Labiidae: Dermaptera e parasitoides, como os microhimenópteros. Foram encontrados três tipos de larvas, sendo classificadas como curculioniforme as mais numerosas, apresentando um total de 57 espécimes coletados.Entomofaunistic survey of artropods in naturally colored cotton fiber in Ipanguaçu-RNAbstract: The objective of this research was to identify the diversity of arthropods associated with cotton crop Gossypium hirsutum L. with colorful plume, it was conducted entomofaunístico survey in Ipanguaçu-RN in production areas. The experimental area was composed of 15 cotton

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.

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.

Effects of environmental temperature on life tables of Rhodnius neivai Lent, 1953 (Hemiptera: Reduviidae under experimental conditions

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Daniel R Cabello

1999-09-01

Full Text Available Changes in life tables of Rhodnius neivai due to variations of environmental temperature were studied, based on nine cohorts. Three cohorts were kept at 22°C, three at 27°C and three at 32°C. Cohorts were censused daily during nymphal instars and weekly in adults. Nine complete horizontal life tables were built. A high negative correlation between temperature and age at first laying was registered (r=-0,84. Age at maximum reproduction was significantly lower at 32°C. Average number of eggs/female/week and total eggs/female on its life time were significantly lower at 22°C. Total number of egg by cohort and total number of reproductive weeks were significantly higher at 27°C. At 32°C, generational time was significantly lower. At 27°C net reproductive rate and total reproductive value were significantly higher. At 22°C, intrinsic growth, finite growth and finite birth rates were significantly lower. At 22°C, death instantaneous rate was significantly higher.

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

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.

Macrogeographic and microgeographic genetic structure of the Chagas' disease vector Triatoma infestans (Hemiptera: Reduviidae) from Catamarca, Argentina.

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Pérez de Rosas, Alicia R; Segura, Elsa L; Fichera, Laura; García, Beatriz Alicia

2008-07-01

The genetic structure in populations of the Chagas' disease vector Triatoma infestans from six localities belonging to areas under the same insecticide treatment conditions of Catamarca province (Argentina) was examined at macrogeographical and microgeographical scales. A total of 238 insects were typed for 10 polymorphic microsatellite loci. The average observed and expected heterozygosities ranged from 0.319 to 0.549 and from 0.389 to 0.689, respectively. The present results confirm that populations of T. infestans are highly structured. Spatial genetic structure was detectable at macrogeographical and microgeographical levels. Comparisons of the levels of genetic variability between two temporal samples were carried out to assess the impact of the insecticide treatment. The genetic diversity of the population was not significantly affected after insecticide use since different genetic parameters (allele number, observed and expected heterozygosities) remained stable. However, loss of low frequency alleles and not previously found alleles were detected. The effective population size (N(e)) estimated was substantially lower in the second temporal sample than in the first; nevertheless, it is possible that the size of the remnant population after insecticide treatment was still large enough to retain the genetic diversity. Very few individuals did not belong to the local T. infestans populations as determined by assignment analyses, suggesting a low level of immigration in the population. The results of the assignment and first-generation migrant tests suggest male-biased dispersal at microgeographical level.

First record of Megaselia scalaris (Loew) (Diptera: Phoridae) infesting laboratory colonies of Triatoma brasiliensis Neiva (Hemiptera: Reduviidae)

International Nuclear Information System (INIS)

Costa, Jane; Almeida, Carlos E.; Esperanca, Gleidson M.; Morales, Ninive; Mallet, Jacenir R. dos S.; Goncalves, Teresa C.M.; Prado, Angelo P. do

2007-01-01

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)

Deltamethrin Binding to Triatoma infestans (Hemiptera: Reduviidae) Lipoproteins. Analysis by Solvent Bar Microextraction Coupled to Gas Chromatography.

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Dulbecco, A B; Mijailovsky, S J; Girotti, J R; Juárez, M P

2015-11-01

The binding of deltamethrin (DLM) to the hemipteran Triatoma infestans (Klug) hemolymph lipoproteins was evaluated in vitro. After DLM incubation with the insect hemolymph, lipoproteins were fractioned by ultracentrifugation. DLM binding was analyzed by a microextractive technique-solvent bar microextraction-a solventless methodology to extract DLM from each lipoprotein fraction. This is a novel use of the technique applied to extract an insecticide from an insect fluid. Capillary gas chromatography with microelectron capture detection was used to detect DLM bound by the T. infestans hemolymph lipoproteins and to identify the preferred DLM carrier. We show that Lp and VHDLp I lipoproteins are mainly responsible for DLM transport in T. infestans, both in DLM-resistant and DLM-susceptible bugs. Our results also indicate that DLM amounts transported are not related to DLM susceptibility. © 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.

First record of Megaselia scalaris (Loew) (Diptera: Phoridae) infesting laboratory colonies of Triatoma brasiliensis Neiva (Hemiptera: Reduviidae)

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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)

Environmental Determinants of the Distribution of Chagas Disease Vector Triatoma dimidiata in Colombia.

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Parra-Henao, Gabriel; Quirós-Gómez, Oscar; Jaramillo-O, Nicolas; Cardona, Ángela Segura

2016-04-01

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 ofT. 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 ofT. 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 ofT. 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 forT. dimidiata hold promise for spatial targeting of integrated vector management. © The American Society of Tropical Medicine and Hygiene.

[Acute Chagas' disease: transmission routes, clinical aspects and response to specific therapy in diagnosed cases in an urban center].

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Shikanai-Yasuda, M A; Lopes, M H; Tolezano, J E; Umezawa, E; Amato Neto, V; Barreto, A C; Higaki, Y; Moreira, A A; Funayama, G; Barone, A A

1990-01-01

The authors report clinical features and therapeutic response of 24 outpatients with acute Chagas' disease, and 3 in the initial chronic phase, referred to the Clinic for Infectious and Parasitic Diseases of the FMUSP "Clínicas" Hospital between 1974 and 1987. The following transmission routes were involved: triatominae in 7 cases, blood transfusion in 9, kidney transplantation and/or blood transfusion in 4, accidental in 1, oral route in 3, probably breast feeding in 1, congenital or breast feeding in 1, and congenital or blood transfusion in 1. Six patients infected by triatominac acquired the disease between 1974 and 1980 and one in 1987. The blood transfusion infected patients acquired the disease in Greater São Paulo, seven of whom after 1983. The acute phase Chagas' disease was oligosymptomatic in 4 patients: three of such patients being immunocompromised by drugs or other diseases. Another two adult immunocompromised patients developed myocarditis and congestive heart failure. Clinical features were severe in 5 from 6 children under two years, irrespective of the transmission route. Evaluation of the acute phase patients treated with benznidazol (4-10 mg/kg/day) showed: therapeutic failure in 4/16 (25.0%); possible cure in 9/16 (53.2%) and inconclusive results in 3/16 (18.8%). The antibody and complement-mediated lysis reaction was in keeping with the xenodiagnosis in 18/22 cases, having shown negative results after treatment earlier than classical serological reactions. One aplastic anaemia patient receiving corticosteroid presented lymphoproliferative disease 6 years after being treated with benznidazol for acute Chagas' disease.

Effect of feeding frequency on the reproductive efficiency of two species of Triatoma with different epidemiological importance

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Claudia Rodríguez

2014-07-01

Full Text Available Introduction In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas, 1909. The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequency on the reproductive parameters of Triatoma patagonica (Del Ponte, 1929 and Triatoma infestans (Klug, 1934, and the effects of starvation on T. patagonica. Methods Couples from both species were fed weekly, or every 3 weeks; in addition, females in couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity (eggs/female, fertility (eggs hatched/eggs laid, initiation and end of oviposition, initiation of mating, number of matings/week, and number of reproductive weeks. Relative meal size index (RMS, blood consumption index (CI, and E values (eggs/mg blood were also calculated. Results Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks for those fed every 3 weeks, or not fed. The reproductive period, RMS index, and CI were lower for T. patagonica than T. infestans. However, despite the lower fecundity of T. patagonica, this species required less blood to produce eggs, with an E values of 2 compared to 2.94 for T. infestans. Conclusions Our results suggest that the differences in fecundity observed between species reflect the availability of food in their natural ecotopes.

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.

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.

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.

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.), My...

Secretory activity and endocrine regulation of male accessory glands in the blood-sucking bug Panstrongylus megistus (Hemiptera: Reduviidae

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Lêda Regis

1987-01-01

Full Text Available The epithelial cells of Panstrongylus megistus male accessory glands (MAG present ultrastructural characteristics of a secretory cell. Their secretory products are accumulated in the lumen of the four MAG lobes. During the first 8 days of adult life a strong secretion activity occurs, accumulating enough material to produce the first spermatophore. Cerebral neurosecretions as well as juvenile hormone are both involved in MAG secretory activity regulation. Juvenile hormone seems to be the responsible for the stimulation of most protein synthesis in male accessory glands. Cerebral neurosecretion seems to be necessary to stimulate juvenile hormone production and release by the corpus allatum. Furthermore, neurosecretion is required for some polypeptides synthesis by MAG. Although topic application of precocene II to adult males does not reproduce the same effects on MAG as does allatectomy, this compound causes strong reduction on male reproductive capacity.

Composição da fauna cavernícola brasileira, com uma análise preliminar da distribuição dos taxons

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Eleonora Trajano

1990-01-01

Full Text Available New data on Brazilian cave fauna are added to previous surveys and the relative abundance and distribution of the cavernicolous taxa is discussed. Terrestrial representatives of several arthropod families and genera are common in both tropical and subtropical Brazilian caves: Endecous and Eidmanacris crickets, Reduviidae heteropterans, Carabidae, Catopinae and Ptilodactylidae beetles, dipterans such as the Chironomidae, Keroplatidae, Phoridae and Drosophilidae, Hydropsychidae trichopterans, Pseudonnanolenidae and Chelodesnidae millipedes, Plato, Ctenus, Loxosceles and Blechroscelis spiders, Pachylinae opilionids, Chernetidae pseudoscorpions and acarians such as the Macrochelidae and Uropodidae. Other taxa are mainly or exclusively tropical Blattelidae, Blattidae and BlaberidaE cockroaches, Histeridae beetles, Noctuoidea moths, social insects as termites and ants, Styloniscidae isopods, Migalomorpha spiders, Amblypigi On the other hand, Psauridae spiders, Goniosoma and Tricommatinae opilionids, Elmidae beetles, and Philosciidae isopods seems to be mainly subtropical. Brazilian aquatic cave fauna seems to be less diversified than the terrestrial one. Siluriform fishes such as pimelodids, trichomycterids and loricariids predominate throughout the country, besides decapod (Macrobrachium shrimps, Potamidae crabs, Aegla anomurans, the latter exclusive of subtropical caves and amphipod (Spelaeogammarus, in tropical caves, and Hyalella crustaceans. Insect larvae (e.g. Elmidae coleopterans, Nematocera dipterans, trichopterans and adults (e.g. Veliidae and Naucoridae heteropterans, Dytiscidae coleopterans, oligochaetes and gastropods such as the Hydrobiidae, are also relatively common. Blechroscelis spiders, Goniosoma opilionids, Zelurus heteropterans, Eidmanacris crickets, Keroplatidae dipterans and Macrobrachium shrimps, among others, live next to the entrance zone in the majority of the caves. But, these animals become troglofiles under certain

Cytogenetic Examination of South American Tapirs, Tapirus Terrestris (Perissodactyla, Tapiridae, from the Wroclaw Zoological Garden

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Kosowska B.

2015-12-01

Full Text Available Cytogenetic Examination of South American Tapirs, Tapirus terrestris (Perissodactyla, Tapiridae from the Wroclaw Zoological Garden. Kosowska, B., Strzała, T., Moska, M., Ratajszczak, R., Dobosz, T. - Seven lowland tapirs (Tapirus terrestris from Wrocław ZOO (three females and four males, differing from each other with exterior and sexual behaviour were verified with cytogenetic analysis in order to check their taxonomic status. Cytogenetic analysis was done using two alternative methods of blood collection: 1 conventionally with venepuncture, and 2 with blood sucking bugs from the Reduviidae family. Lymphocytes capable of growing were obtained only with conventional method of blood sampling. Karyotypes and karyograms of all analyzed tapirs were created using classical cytogenetic methods of chromosomes staining. All possessed karyograms had diploid chromosome number equal 80 (2n = 80. Homologous chromosomes did not differ between each other with quantity, size, centromeres location, length of arms, G bands and all were classified as proper karyograms of Tapirus terrestris species representatives. The X chromosomes as well as the first pair of chromosomes (both metacentric, were the largest among all analyzed, respectively. All remaining 38 pairs of chromosomes were acrocentric with Y chromosome as the smallest one (in males’ karyograms. Blood collected with blood sucking bugs proved to be unsuitable for cell culture. None of the seven established cultures was effective as lymphocytes obtained with this method did not show growth potential in prepared media. Thus, blood collected from the tapirs via Dipetalogaster maxima species did not show usefulness for cytogenetic studies due to the inability of cells to proliferation, even after a relatively short period of time elapsed since the blood sampling (1 to 2 hours.

Modeling the effects of palm-house proximity on the theoretical risk of Chagas disease transmission in a rural locality of the Orinoco basin, Colombia

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Diana Erazo

2016-11-01

Full Text Available Abstract Background Chagas disease is a major public health concern in Latin America and it is transmitted by insects of the subfamily Triatominae, including Rhodnius spp. Since palm trees are ubiquitous in Colombia and a habitat for Rhodnius spp., the presence of palms near villages could increase contact rates between vectors and humans. Therefore, knowing whether a relationship exists between the proximity of palms to villages and the abundance and distribution of vectors therein, may be critical for Chagas disease prevention programs. Adapting a mathematical model for R. prolixus population dynamics in a small village, we model the implications of changing distances between palms and dwellings, to the risk of Chagas disease infection. Methods We implemented a mathematical model that reflects R. prolixus population dynamics in a small village located in the department of Casanare (Colombia to study the role of palm-house proximity. We varied the distance between palms and houses by monitoring the network global efficiency metric. We constructed 1,000 hypothetical villages varying distances and each one was run 100 times. Results According to the model, as palm-house proximity increases, houses were more likely to be visited by triatomine bugs. The number of bugs per unit time increased progressively in a non-linear fashion with high variability. We stress the importance of village configuration on the model output. Conclusions From a theoretical perspective, palm-house proximity may have a positive effect on the incidence of Chagas disease. The model predicts a 1% increase in new human cases per year when houses and palms are brought closer by 75%.

Combate ao Panstrongylus megistus com o Malathion concentrado

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Ítalo A. Sherlock

1975-12-01

Full Text Available O Malathion concentrado (0-0 dimetilfosforo ditioato de dietil mercapto - succinato foi usado para combater o Panstrongylus megistus, principal vector da doença de Chagas, numa zona endêmica do Estado da Bahia. A eficácia do malathion no controle desse triatomíneo foi constatada após ter sido aplicado três vezes, no período de um ano e meio, em intervalos senjestrais. A ação letal do inseticida tanto se faz sobre as formas ambulantes, como sobre os ovos de P. megistus. Em vista da eficácia para o controle do triatomíneo, de não terem sido observados efeitos tóxicos colaterais para o homem e do custo operacional ser relativamente baixo, os Autores concluem que o malathion é uma arma valiosa para uso nas campanhas contra os transmissores da doença de Chagas.Concentrated Malathion was used against Panstrongylus megistus, the principal local vector of Chagas' Disease, in an endemic area in the State of Bahia, Brasil. The efficacy of malathion in the controle of this triatominae was demonstrated after three applications six months apart. The insecticide is lethal to all stages of vector including the eggs. In view of its effectiveness in the control of the triatomine, the absence of any noticeable signs of intoxication in the personnel applying the insecticide and in residents of the treated houses or domestic animals, and the relatively low operational cost, the Authors conclude that malathion is a valuable weapon in campaigns to control the veçtors of Chagas Disease.

Pioneer study of population genetics of Rhodnius ecuadoriensis (Hemiptera: Reduviidae) from the central coastand southern Andean regions of Ecuador.

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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.

Estudos bionômicos de Dipetalogaster maximus (Uhler, 1894 (Hemiptera - Triatominae: II - Influência da dieta sobre o ciclo biológico e resistência ao jejum Bionomic studies of Dipetalogaster maximus (Uhler, 1894 (Hemiptera: Triatominae: II. Influence of diet on the biological cycle and resitance to fast

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Jane Margaret Costa

1987-03-01

Full Text Available Avaliou-se a influência de dois tipos de dieta na cronologia da ontogênsese de Dipetalogaster maximus. Alimentou-se um grupo em sangue de camundongos normais (C e outro em sangue de pombos (P. Ambos foram mantidos em estufa B.O.D. a 28ºC e 65% U.R. O grupo alimentado em C, atingiu a fase adulta com X=130,1 dias e o grupo alimentado em P com X=145,68 dias. A percentagem total de mortalidade foi significativamente superior nos alimentados em P (63,71% em relação aos alimentados em C (31,18%. Quanto á resistência ao jejum, o período de sobrevivência foi acentuadamente maior para o grupo alimentado em C. Principalmente nos 3º, 4º e 5º estádios. Estas observações complementam nossos registros anteriores desta espécie, mantida nas mesmas condições, sobre: fertilidade das fêmeas, ritmo de postura, viabilidade dos ovos e curva da mortalidade x fertilidade.Two kinds of blood-meal were assayed in order to broaden the knowledge of the biology of Dipetalogaster maximus: one group of insects was fed on normal mouse blood (C and another group fed on pigeon blood (P. Both groups were kept in a B.O.D. - chamber (28ºC and 65% R.H.. Significant data concerning their development was registered: the group fed on C reached the adult stage in X = 130,1 days and the group fed on P in X = 145,6 days. Mortality of group fed on P, (63,71% was doubled that of group fed on C (31,18%. The period of survival, as measured by resistance to starvation, was markedly greater in group fed on C, particularly in the third, fourth and fifth stages. These observations complete our former records of this species, kept under the same conditions of female fertility, egg vialbility and comparative mortality and fertility rates.

Doença de Chagas aguda: vias de transmissão, aspectos clínicos e resposta à terapêutica específica em casos diagnosticados em um centro urbano Acute Chagas' disease: transmission mechanisms, clinical features and specific therapeutic response in cases diagnosed in an urban center

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M.A. Shikanai-Yasuda

1990-02-01

. The following transmission routes were involved: triatominae in 7 cases, blood transfusion in 9, kidney transplantation and/or blood transfusion in 4, accidental in 1, oral route in 3, probably breast feeding in 1, congenital or breast feeding in 1, and congenital or blood transfusion in 1. Six patients infected by triatominae acquired the disease between 1974 and 1980 and one in 1987. The blood transfusion infected patients acquired the disease in Greater São Paulo, seven of whom after 1983. The acute phase Chagas' disease was oligosymptomatic in 4 patients: three of such patients being immunocompromised by drugs or other diseases. Another two adult immunocompromised patients developed myocarditis and congestive heart failure. Clinical features were severe in 5 from 6 children under two years, irrespective of the transmission route. Evaluation of the acute phase patients treated with benznidazol (4-10 mg/kg/day showed: therapeutic failure in 4/16 (25.0%; possible cure in 9/16 (53.2% and inconclusive results in 3/16 (18.8%. The antibody and complement-mediated lysis reaction was in keeping with the xenodiagnosis in 18/22 cases, having shown negative results after treatment earlier than classical serological reactions. One aplastic anaemia patient receiving corticosteroid presented lymphoproliferative disease 6 years after being treated with benznidazol for acute Chagas' disease.

Responses of Cerambycidae and Other Insects to Traps Baited With Ethanol, 2,3-Hexanediol, and 3,2-Hydroxyketone Lures in North-Central Georgia.

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Miller, D R; Crowe, C M; Mayo, P D; Silk, P J; Sweeney, J D

2015-10-01

In north-central Georgia, 13 species of woodboring beetles (Coleoptera: Cerambycidae: Cerambycinae) were attracted to multiple-funnel traps baited with ethanol and one of the following pheromones: (1) racemic 3-hydroxyhexan-2-one; (2) racemic 3-hydroxyoctan-2-one; and (3) syn-2,3-hexanediol. The following species were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one: Anelaphus pumilus (Newman), Eburia quadrigeminata (Say), Euderces pini (Olivier), Knulliana cincta (Drury), Neoclytus mucronatus (F.), Neoclytus scutellaris (Olivier), and Xylotrechus colonus (F.). Clytus marginicollis Castelnau & Gory, and Anelaphus parallelus (Newman) were attracted to traps baited with ethanol and 3-hydroxyoctan-2-one, whereas traps baited with ethanol and syn-2,3-hexanediol were attractive to Anelaphus villosus (F.), A. parallelus, Neoclytus acuminatus (F.), Neoclytus jouteli jouteli Davis, and Megacyllene caryae (Gahan). Ethanol enhanced catches of seven cerambycid species in traps baited with syn-2,3-hexanediol and 3,2-hydroxyketones. Catches of bark and ambrosia beetles (Curculionidae: Scolytinae) in ethanol-baited traps were largely unaffected by the addition of syn-2,3-hexanediol and 3,2-hydroxyketone lures, except for two species. The mean catches of Hypothenemus rotundicollis Wood & Bright and Dryoxylon onoharaensum (Murayama) in ethanol-baited traps increased and decreased, respectively, with the addition of racemic 3-hydroxyoctan-2-one. Traps baited with ethanol and syn-2,3-hexanediol were attractive to Xylobiops basilaris (Say) (Bostrichidae) and Chariessa pilosa (Forster) (Cleridae), whereas Temnoscheila virescens (F.) (Trogossitidae) were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one. The assassin bug, Apiomerus crassipes (F.) (Hemiptera: Reduviidae), was attracted to traps baited with ethanol and 3,2-hydroxyketones. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US

Aspects of peridomiciliary ecotopes in rural areas of Northeastern Brazil associated to triatomine (Hemiptera, Reduviidae infestation, vectors of Chagas disease

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Otília Sarquis

2006-03-01

Full Text Available Artificial ecotopes of 121 peridomiciliary environments in four rural localities in the state of Ceará, Brazil, were studied and the type of material of the ecotopes was identified as triatomine infestation. Two thousand two hundred and four Triatoma brasiliensis Neiva, 340 Triatoma pseudomaculata Corrêa and Espínola, 121 Rhodnius nasutus Stall, and 5 Panstrongylus lutzi (Neiva and Pinto were captured. Out of the 323 ecotopes found (X =2.0 ± 1.8 per dwelling such as pigpens, henhouses, corrals, perches, dovecotes, piles of roofing tiles, bricks, wood, and straw 30.3% were infested by triatomines in all different developmental stages, including eggs. A substantial number of triatomines were found in perches, however the largest infestation took place in roofing materials used in the construction of goat/sheep corrals, henhouses, and pigpens, where 98% of them were captured: 1372 triatomines were located in the roofing tile covers, 285 in the straw, 187 in the perches, 77 in the coverings of roofing tiles and straw, and 13 in the straw and wood. Among all the different pile of materials, roofing tiles were the most infested (50% followed by bricks (38.9% and woods (36.1%. T. brasiliensis colonized mainly brick piles (chi2=16.539; p < 0.05 and roofing tiles (chi2=5,090.58; p < 0.05; T. pseudomaculata preferred wood perches (chi2= 472.39; p < 0.05 and woodpiles (chi2=126.0 p < 0.05, and R. nasutus was principally found in roofing straw (chi2=384.43; p < 0.05. These findings suggest that triatomines tend to colonize peridomiciliary ecotopes similar to their original habitats.

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.

Changes related to gender, geographic population and habitat in the antennal phenotype of Triatoma patagonica Del Ponte, 1929 (Hemiptera: Reduviidae).

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Rodríguez, Claudia S; Crocco, Liliana; Altamirano, Alejandra; Catalá, Silvia

2013-02-01

Triatomines undergo morphological changes as an adaptive response to different habitats (wild, peridomestic, domestic, laboratory). The characterization of the antennal phenotype provides information on intraspecific variation caused by geographical origin and/or habitat. Triatoma patagonica Del Ponte, 1929 is known to occur in peridomiciles of rural areas in Argentina, where it also invades non-colonized dwellings. Here we describe and compare the antennal phenotype of T. patagonica in populations of different geographic origin, and explore possible modifications induced by laboratory rearing with the aim of investigating the range of phenotypic variation of the species for the first time. Sixty antennas of adult males and females of T. patagonica belonging to two peridomiciliary populations of different geographical origin were analyzed. Four types of sensilla were observed in three antennal segments, showing sexual dimorphism in the species. The multivariate analysis separated the populations of similar habitat (peridomicile) but different geographical origin, without showing differences between the peridomiciliary and laboratory populations of the same geographical origin. These results suggest phenotypic plasticity in T. patagonica, which would allow the species to adapt to a wide range of habitats without having a close association with a given host and its environment. The range of antennal phenotypic variation of T. patagonica would also be an indicator of its current stage of adaptation to the human environment. Copyright © 2012 Elsevier B.V. All rights reserved.

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.

Reproductive isolation revealed in preliminary crossbreeding experiments using field collected Triatoma dimidiata (Hemiptera: Reduviidae) from three ITS-2 defined groups.

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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.

Reproductive isolation revealed in preliminary crossbreeding experiments using field collected Triatoma dimidiata (Hemiptera: Reduviidae) from three ITS–2 defined groups

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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

Reproductive isolation revealed in preliminary crossbreeding experiments using field collected Triatoma dimidiata (Hemiptera: Reduviidae) from three ITS–2 defined groups

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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 ...

Irradiation effects on the duration of intermolt in nymphs of the fourth instar of Panstrongylus megistus Burmeister, 1835 (Hemiptera: Reduviidae)

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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

Alimentación y defecación en triatominos del género Rhodnius (Hemiptera: Reduviidae alimentados con sangre humana

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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.

Is imidacloprid an effective alternative for controlling pyrethroid-resistant populations of Triatoma infestans (Hemiptera: Reduviidae in the Gran Chaco ecoregion?

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Guillermo Carvajal

2014-09-01

Full Text Available 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.

Insecticidal activity of venomous saliva from Rhynocoris fuscipes (Reduviidae against Spodoptera litura and Helicoverpa armigera by microinjection and oral administration

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K Sahayaraj

2011-01-01

Full Text Available Rhynocoris fuscipes is a potential predator of many economically important pests in India. In the present study, its venomous saliva (VS was collected by milking and diluted with HPLC grade water to different concentrations (200, 400, 600, 800 and 1000 ppm. Microinjection of Rhynocoris fuscipes VS was more toxic than its oral administration in Helicoverpa armigera (cotton bollworm and Spodoptera litura (tobacco cutworm. Thus, R. fuscipes VS was found to be toxic to third instar S. litura and H. armigera with respective LD50s of 846.35 and 861.60 ppm/larva at 96 hours after microinjection. The current results showed that VS of Rhynocoris fuscipes caused mortality of H. armigera and S. litura. Active peptides from VS may be isolated, identified and assessed for their impact in order to ascertain how they alter the physiology of these pests, information that could be applicable in pest management programs.

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.

Blood meal sources of wild and domestic Triatoma infestans (Hemiptera: Reduviidae) in Bolivia: connectivity between cycles of transmission of Trypanosoma cruzi.

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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.

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.

Life cycle and reproductive patterns of Triatoma rubrovaria (Blanchard, 1843 (Hemiptera: Reduviidae under constant and fluctuating conditions of temperature and humidity

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Damborsky Miryam P.

2005-01-01

Full Text Available The aim of this study was to evaluate the temperature and relative humidity influence in the life cycle, mortality and fecundity patterns of Triatoma rubrovaria. Four cohorts with 60 recently laid eggs each were conformed. The cohorts were divided into two groups. In the controlled conditions group insects were maintained in a dark climatic chamber under constant temperature and humidity, whereas triatomines of the ambiental temperature group were maintained at room temperature. Average incubation time was 15.6 days in the controlled conditions group and 19.1 days in the ambiental temperature. In group controlled conditions the time from egg to adult development lasted 10 months while group ambiental temperature took four months longer. Egg eclosion rate was 99.1% and 98.3% in controlled conditions and ambiental temperature, respectively. Total nymphal mortality in controlled conditions was 52.6% whereas in ambiental temperature was 51.8%. Mean number of eggs/female was 817.6 controlled conditions and 837.1 ambiental temperature. Fluctuating temperature and humidity promoted changes in the life cycle duration and in the reproductive performance of this species, although not in the species mortality.

Ultrastructural studies of the hemocytes of Panstrongylus megistus (Hemiptera: Reduvidae Ultra-estrutura dos hemócitos de Panstrongylus megistus (Hemiptera: Reduviidae

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Margherita A. Barracco

1989-06-01

Full Text Available Ultrastructural analyses revealed the presence of six hemocyte types in the hemolymph of Panstrogylus megistus, partially confirming our previous results obtained through light microscopy. Prohemocytes: small, round hemocytes with a thin cytoplasm layer, espcieally rich in free ribosomes and poor in membranous systems. Plasmatocytes: polymorphic cells, whose cytoplasm contains many lysosomes and a well developed rough endoplasmic reticulum (RER.They are extremely phagocytic. Sometimes, they show a large vacuolation. Granulocytes: granular hemocytes whose granules show different degrees of electrondensity. Most of them, have an internal structuration. Coagulocytes: oval or elongated hemocytes, which show pronounced perinuclear cisternae as normally observed in coagulocytes. The cytoplasm is usually electrondense, poor in membranous systems and contains many labile granules. Oenocytoids: large and very stable hemocytes, whose homogeneous cytoplasme is rich in loose ribosomes and poor in membranous systems. Adipohemocytes: large cells, containing several characteristic lipid droplets. The cytoplasm is also rich in glycogen, RER and large mitochondria. The total and differential hemocyte count (THC and DHC were also calculated for this reduviid. THC increases from 2,900 hemocytes/cubic millimeter of hemolymph in the 4th intar to 4,350 in the 5th and then, decreases to 1,950 in the adults. Plasmatocytes and coagulocytes are the predominant hemocyte types.Estudos ao microscópio eletrônico de transmissão revelaram a presença de seis tipos de hemócitos na hemolinfa de Panstrongylus megistus. Estes resultados confirmam parcialmente os obtidos anteriormente através da microscopia de luz. Pró-hemócitos: células pequenas e arredondadas, cuja delgada faixa citoplasmática é especialmente rica em ribossomos livres e pobre em sistemas membranosos. Plasmatócitos: células polimórficas, cujo citoplasma caracteriza-se por um retículo endoplasmático rugoso (RER bem desenvolvido e principalmente pela sua abundância em lisossomos. São células tipicamente fagocitárias. Algumas vezes, seu citoplasma mostra-se extremamente vacuolizado. Granulócitos: hemócitos granulares, cujos grânulos mostram diferentes graus de eletrondensidade e podem ou não apresentar estruturação interna. Coagulócitos: hemócitos ovalados ou fusiformes que se caracterizam pela presença de acentuadas cisternas perinucleares. O citoplasma é geralmente eletrondenso, pobre em organelas membranosas e contêm grânulos frágeis. Enocitóides: hemócitos grandes e muito estáveis em sua morfologia. Seu citoplasma é homogêneo, rico em ribossomos livres e pobre em sistemas membranosos. Adipo-hemócitos: células grandes que apresentam inclusões lipídicas características. Seu citoplasma é também rico em glicogênio RER e mitocôndrias grandes. As contagens totais (THC e diferenciais (DHC de hemócitos foram também calculadas. A THC cresce de 2.900 hemócitos/[milímetro cúbico] de hemolinfa em ninfas de 4º estágio para 4.350 em ninfas de 5º estágio. Há, no entanto, um decréscimo significativo nos adultos, onde a THC passa para 1.950 hemócitos/[milímetro cúbico] de hemolinfa. Plasmatócitos e coagulócitos são os hemócitos hemolinfa. Plasmatócitos e coagulócitos são os hemócitos predominantes em P. megistus.

Enfermedad de chagas en la Región Nororiental del Perú. I. Triatominos (Hemiptera, Reduviidae presentes en Cajamarca y Amazonas

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Abraham G Cáceres

2002-01-01

Full Text Available Objetivos: Conocer la diversidad de triatominos presentes en las provincias de San Ignacio y Jaén (Cajamarca y en Bagua, Condorcanqui y Utcubamba (Amazonas. Materiales y métodos: los triatominos fueron capturados de mayo 1995 a diciembre 2000 en el intra y peridomicilios de las viviendas de las provincias de San Ignacio (5 distritos y Jaén (10 distritos del departamento de Cajamarca, y en 5 distritos de Bagua, un distrito de Condorcanqui y en seis de Utcubamba (Amazonas. El muestreo fue de 08:00 a 19:00 horas con alambre de 30 cm de largo, pinzas largas y linterna de mano. Resultados: se capturaron 5567 triatominos pertenecientes a cinco especies. Panstrongylus herreri fue la especie más predominante (94%. 90% del total de triatominos fueron capturados en ambientes intradomiciliarios. Se reporta Rhodnius robustus por primera vez para Amazonas. Ejemplares de R. ecuadoriensis y R. robustus, fueron colectados en intradomicilios en porcentajes mínimos en Sallique, provincia de Jaén (Cajamarca y Nieva, provincia de Condorcanqui (Amazonas. Panstrongylus geniculatus fue colectado en intradomicilios. Se reporta en ciertas localidades de La Coipa, Huarango y Namballe (San Ignacio; así como en Bellavista y Santa Rosa (Jaén y en Aramango, Copallín e Imaza (Bagua; además, en Jamalca, Cajaruro y Bagua Grande (Utcubamba. Panstrongylus chinai, especie silvestre con tendencia a domesticarse, se encontró en Santa Rosa, Bellavista, Chontalí y San José del Alto (Jaén y en Namballe, San Ignacio, La Coipa y Chirinos (San Ignacio. También se encontró en Cajaruro y Bagua Grande (Utcubamba. 90% de P. herreri fueron colectados en el interior de las viviendas. Para Cajamarca se ha colectado en Pomahuaca, Pucará, San José del Alto, Pirias, Bellavista, Santa Rosa, La Coipa y Huarango; mientras que para Amazonas en Aramango, Parco, Bagua Grande, Cajaruro y El Milagro.

Behavior of triatomines (Hemiptera: Reduviidae vectors of Chagas' disease: I. Courtship and copulation of Panstrongylus megistus (Burm-1835 in the laboratory

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Marli Maria Lima

1986-03-01

Full Text Available A study of the courship and copulation behaviour of Panstrongylus megistus was carried out in the laboratory. fifty-five newly-fed virgin couples were used. Experiments were performed during the day (9:00 to 12:00 a.m. and at night (7:00 to 10:00 p.m. Behaviour was recorded by direct observation and was found to consist of the following sequence of behavioral patterns: the male approached the female and jumped on her or mounted her; he took on a dorsolateral position and immobilized the female dorsally and ventrally with his three pairs of legs; the male genital was placed below those of the female; the paramers of the male immobilized the female's genitals; copulation started. The couple joined by the iniciative of the male. The female could be receptive and accept copulation, or nonreceptive and reject the male. Copulation occurred more often on the occasion of the first attempt by the male. Duration of copulation was X = 29.3 ± 9.3 min (CV = 83%. No behavioral differences were observed couples tested during the day or at night.O estudo do comportamento de cópula de Panstrongylus megistus foi feito em laboratório. Foram utilizados 55 casais virgens, recém-alimentados. As experiências efetuaram-se de dia (9-12h e à noite (19-21h. O registro do comportamento foi feito por observação direta, constatando-se uma seqüência de padrões comportamentais caracterizados por: o macho se aproxima e salta sobre a fêmea; assume posição dorso-lateral e imobiliza a fêmea, dorsal e ventralmente, com os três pares de patas; a genitália masculina se coloca abaixo da feminina; os parâmeros do macho atuam na imobilização da genitália da fêmea; iniciam a cópula. A aproximação dos casais se dá por iniciativa do macho, podendo a fêmea estar receptiva, facilitando a cópula, ou não receptiva, rejeitando o macho. A cópula é mais freqüente na primeira tentativa do macho. A duração do período de cópula foi de X = 29.3 + ou - 9.1 min (CV = 83%. Não houve diferenças comportamentais entre os casais testados durante o dia e à noite.

Domestic Rhodnius ecuadoriensis (Hemiptera, Reduviidae) infestation in Northern Peru: a comparative trial of detection methods during a six-month follow-up.

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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.

Contribution of Oswaldo Paulo Forattini to public health: analysis of scientific production.

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Reis, Juliana Gonçalves; Kobayashi, Keilla Miki; Ueno, Helene Mariko; Ribeiro, Cristiane Martins; Cardoso, Telma Abdalla de Oliveira

2016-12-22

To analyze the main characteristics of the scientific production of Oswaldo Paulo Forattini, researcher and, for 40 years, editor of Revista de Saúde Pública. Descriptive study with bibliometric approach conducted in three steps. (1) identification of bibliographic records using the following search strategy: "Oswaldo Paulo Forattini" OR "Forattini OP" OR "Forattini" up information sources Google Scholar, Web of Science, and PubMed, in July 2016, which retrieved 867 records. (2) composition of research corpus, in which we included 351 bibliographic records of articles, books, book chapters, editorials, book reviews, informative notes and annual reports of the RSP and excluded 516 duplicates and acknowledgement notes, obituary notes, and nonretrievable citations. (3) data organization and analysis, in which we built databases for descriptive analysis and development of the MeSH coauthors and terms networks in VOSviewer software. For analysis of editorials, three reviewers read the full text of each editorial and categorized them according to subject, historical context and perspectives, relating them with historical milestones. Forattini's scientific production occurred from 1946 to 2009, most consisting of articles (n = 218; 62.1%), editorials (n = 43; 12.3%), and books (n = 13; 3.7%). The main subjects were Culicidae (36.8%), Triatominae (12.5%), and Epidemiology (10.0%). The coauthors of articles were his professors, colleagues of his generation, and graduate students. His editorials addressed critical reflections on the production of knowledge, research priorities, and factors that contributed to or hindered progress. The scope of subjects is broad, referring to socioeconomic and scientific development, public health issues in developed countries, or global health. The analysis shows Forattini's commitment with public health, research with vectors, training of researchers, and scientific communication. Analisar as principais características da produ

Estructura poblacional y variabilidad genética de Rhodnius prolixus (Hemiptera: Reduviidae procedente de diferentes áreas geográficas de Colombia

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Diana Carolina López

2007-01-01

Resultados. R. prolixus presenta variabilidad genética moderada (Fst 0,057-0,15, entre las poblaciones domiciliadas se encontraron tasas de migración (Nm>1 que revelan flujo genético. Se encontró diferenciación genética de moderada-alta entre la población silvestre de Casanare y las poblaciones domésticas del centro del país (Tolima y Cundinamarca. Conclusión. Las poblaciones domiciliadas de R. prolixus son homogéneas debido a que existe flujo genético entre éstas; lo cual es favorable para el control químico, mientras que la población silvestre agrupa aparte de las domiciliadas. Se evidencia la necesidad de estudiar la estructura genética de los focos silvestres, sus posibles rutas de dispersión y el riesgo epidemiológico que representan.

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.

Geographical Variation of Deltamethrin Susceptibility of Triatoma infestans (Hemiptera: Reduviidae) in Argentina With Emphasis on a Resistant Focus in the Gran Chaco.

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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.

Modeling horizontal gene transfer (HGT in the gut of the Chagas disease vector Rhodnius prolixus

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Durvasula Ravi V

2011-05-01

Full Text Available Abstract Background Paratransgenesis is an approach to reducing arthropod vector competence using genetically modified symbionts. When applied to control of Chagas disease, the symbiont bacterium Rhodococcus rhodnii, resident in the gut lumen of the triatomine vector Rhodnius prolixus (Hemiptera: Reduviidae, is transformed to export cecropin A, an insect immune peptide. Cecropin A is active against Trypanosoma cruzi, the causative agent of Chagas disease. While proof of concept has been achieved in laboratory studies, a rigorous and comprehensive risk assessment is required prior to consideration of field release. An important part of this assessment involves estimating probability of transgene horizontal transfer to environmental organisms (HGT. This article presents a two-part risk assessment methodology: a theoretical model predicting HGT in the gut of R. prolixus from the genetically transformed symbiont R. rhodnii to a closely related non-target bacterium, Gordona rubropertinctus, in the absence of selection pressure, and a series of laboratory trials designed to test the model. Results The model predicted an HGT frequency of less than 1.14 × 10-16 per 100,000 generations at the 99% certainty level. The model was iterated twenty times, with the mean of the ten highest outputs evaluated at the 99% certainty level. Laboratory trials indicated no horizontal gene transfer, supporting the conclusions of the model. Conclusions The model treats HGT as a composite event, the probability of which is determined by the joint probability of three independent events: gene transfer through the modalities of transformation, transduction, and conjugation. Genes are represented in matrices and Monte Carlo method and Markov chain analysis are used to simulate and evaluate environmental conditions. The model is intended as a risk assessment instrument and predicts HGT frequency of less than 1.14 × 10-16 per 100,000 generations. With laboratory studies that

Multi-criteria decision analysis and spatial statistic: an approach to determining human vulnerability to vector transmission of Trypanosoma cruzi

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Diego Montenegro

Full Text Available BACKGROUND Chagas disease (CD, caused by the protozoan Trypanosoma cruzi, is a neglected human disease. It is endemic to the Americas and is estimated to have an economic impact, including lost productivity and disability, of 7 billion dollars per year on average. OBJECTIVES To assess vulnerability to vector-borne transmission of T. cruzi in domiciliary environments within an area undergoing domiciliary vector interruption of T. cruzi in Colombia. METHODS Multi-criteria decision analysis [preference ranking method for enrichment evaluation (PROMETHEE and geometrical analysis for interactive assistance (GAIA methods] and spatial statistics were performed on data from a socio-environmental questionnaire and an entomological survey. In the construction of multi-criteria descriptors, decision-making processes and indicators of five determinants of the CD vector pathway were summarily defined, including: (1 house indicator (HI; (2 triatominae indicator (TI; (3 host/reservoir indicator (Ho/RoI; (4 ecotope indicator (EI; and (5 socio-cultural indicator (S-CI. FINDINGS Determination of vulnerability to CD is mostly influenced by TI, with 44.96% of the total weight in the model, while the lowest contribution was from S-CI, with 7.15%. The five indicators comprise 17 indices, and include 78 of the original 104 priority criteria and variables. The PROMETHEE and GAIA methods proved very efficient for prioritisation and quantitative categorisation of socio-environmental determinants and for better determining which criteria should be considered for interrupting the man-T. cruzi-vector relationship in endemic areas of the Americas. Through the analysis of spatial autocorrelation it is clear that there is a spatial dependence in establishing categories of vulnerability, therefore, the effect of neighbors’ setting (border areas on local values should be incorporated into disease management for establishing programs of surveillance and control of CD via vector

Multi-criteria decision analysis and spatial statistic: an approach to determining human vulnerability to vector transmission of Trypanosoma cruzi.

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Montenegro, Diego; Cunha, Ana Paula da; Ladeia-Andrade, Simone; Vera, Mauricio; Pedroso, Marcel; Junqueira, Angela

2017-10-01

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is a neglected human disease. It is endemic to the Americas and is estimated to have an economic impact, including lost productivity and disability, of 7 billion dollars per year on average. To assess vulnerability to vector-borne transmission of T. cruzi in domiciliary environments within an area undergoing domiciliary vector interruption of T. cruzi in Colombia. Multi-criteria decision analysis [preference ranking method for enrichment evaluation (PROMETHEE) and geometrical analysis for interactive assistance (GAIA) methods] and spatial statistics were performed on data from a socio-environmental questionnaire and an entomological survey. In the construction of multi-criteria descriptors, decision-making processes and indicators of five determinants of the CD vector pathway were summarily defined, including: (1) house indicator (HI); (2) triatominae indicator (TI); (3) host/reservoir indicator (Ho/RoI); (4) ecotope indicator (EI); and (5) socio-cultural indicator (S-CI). Determination of vulnerability to CD is mostly influenced by TI, with 44.96% of the total weight in the model, while the lowest contribution was from S-CI, with 7.15%. The five indicators comprise 17 indices, and include 78 of the original 104 priority criteria and variables. The PROMETHEE and GAIA methods proved very efficient for prioritisation and quantitative categorisation of socio-environmental determinants and for better determining which criteria should be considered for interrupting the man-T. cruzi-vector relationship in endemic areas of the Americas. Through the analysis of spatial autocorrelation it is clear that there is a spatial dependence in establishing categories of vulnerability, therefore, the effect of neighbors' setting (border areas) on local values should be incorporated into disease management for establishing programs of surveillance and control of CD via vector. The study model proposed here is flexible and

Evolutionary and dispersal history of Triatoma infestans, main vector of Chagas disease, by chromosomal markers.

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Panzera, Francisco; Ferreiro, María J; Pita, Sebastián; Calleros, Lucía; Pérez, Ruben; Basmadjián, Yester; Guevara, Yenny; Brenière, Simone Frédérique; Panzera, Yanina

2014-10-01

Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known as Andean and non-Andean chromosomal groups, that are highly differentiated by the amount of heterochromatin and genome size. Analyses with nuclear and mitochondrial sequences are not conclusive about resolving the origin and spread of T. infestans. The present paper includes the analyses of karyotypes, heterochromatin distribution and chromosomal mapping of the major ribosomal cluster (45S rDNA) to specimens throughout the distribution range of this species, including pyrethroid-resistant populations. A total of 417 specimens from seven different countries were analyzed. We show an unusual wide rDNA variability related to number and chromosomal position of the ribosomal genes, never before reported in species with holocentric chromosomes. Considering the chromosomal groups previously described, the ribosomal patterns are associated with a particular geographic distribution. Our results reveal that the differentiation process between both T. infestans chromosomal groups has involved significant genomic reorganization of essential coding sequences, besides the changes in heterochromatin and genomic size previously reported. The chromosomal markers also allowed us to detect the existence of a hybrid zone occupied by individuals derived from crosses between both chromosomal groups. Our genetic studies support the hypothesis of an Andean origin for T. infestans, and suggest that pyrethroid-resistant populations from the Argentinean-Bolivian border are most likely the result of

First record of the genus Tagalis Stål, 1860 (Hemiptera: Reduviidae: Saicinae) from Colombia with the description of two new species .

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Castro-Huertas, Valentina; Forero, Dimitri

2014-07-21

Tagalis Stål is recorded for the first time from Colombia and two species are described as new: Tagalis dichroa sp. nov., from Acandí (Chocó), and Tagalis albispina sp. nov., from Gorgona Island (Cauca). Based on the structure of the male genitalia of the known species, we here propose at least four species groups within Tagalis: 1) T. evavilmae, 2) T. femorata, 3) T. baenai, T. grossii, and T. marquesi, and 4) T. dichroa sp. nov., T. inornata, and T. seminigra. Tagalis albispina sp. nov. known only from the female holotype, cannot be placed into this scheme. Digital micrographs of the habitus and genitalia of the new species are provided. An updated key to the species of Tagalis is presented to facilitate the identification of the new species.

Functional Response of the Predators Alloeocranum biannulipes (Hemiptera: Reduviidae) and Teretrius nigrescens (Coleoptera: Histeridae) Feeding on Dinoderus porcellus (Coleoptera: Bostrichidae) Infesting Yam Chips.

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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.

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.

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%.

β-chain of ATP synthase as a lipophorin binding protein and its role in lipid transfer in the midgut of Panstrongylus megistus (Hemiptera: Reduviidae).

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Fruttero, Leonardo L; Demartini, Diogo R; Rubiolo, Edilberto R; Carlini, Célia R; Canavoso, Lilián E

2014-09-01

Lipophorin, the main lipoprotein in the circulation of the insects, cycles among peripheral tissues to exchange its lipid cargo at the plasma membrane of target cells, without synthesis or degradation of its apolipoprotein matrix. Currently, there are few characterized candidates supporting the functioning of the docking mechanism of lipophorin-mediated lipid transfer. In this work we combined ligand blotting assays and tandem mass spectrometry to characterize proteins with the property to bind lipophorin at the midgut membrane of Panstrongylus megistus, a vector of Chagas' disease. We further evaluated the role of lipophorin binding proteins in the transfer of lipids between the midgut and lipophorin. The β subunit of the ATP synthase complex (β-ATPase) was identified as a lipophorin binding protein. β-ATPase was detected in enriched midgut membrane preparations free of mitochondria. It was shown that β-ATPase partially co-localizes with lipophorin at the plasma membrane of isolated enterocytes and in the sub-epithelial region of the midgut tissue. The interaction of endogenous lipophorin and β-ATPase was also demonstrated by co-immunoprecipitation assays. Blocking of β-ATPase significantly diminished the binding of lipophorin to the isolated enterocytes and to the midgut tissue. In vivo assays injecting the β-ATPase antibody significantly reduced the transfer of [(3)H]-diacylglycerol from the midgut to the hemolymph in insects fed with [9,10-(3)H]-oleic acid, supporting the involvement of lipophorin-β-ATPase association in the transfer of lipids. In addition, the β-ATPase antibody partially impaired the transfer of fatty acids from lipophorin to the midgut, a less important route of lipid delivery to this tissue. Taken together, the findings strongly suggest that β-ATPase plays a role as a docking lipophorin receptor at the midgut of P. megistus. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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.

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; Víctor Manuel Angulo

2009-01-01

Introducción. A pesar de la importancia de Triatoma dimidiata como vector de la enfermedad de Chagas, poco se conoce de su ciclo biológico y de la producción eficiente de insectos disponibles para ensayos biológicos. Objetivo. Determinar las características del ciclo de vida en el laboratorio y establecer las condiciones del estado nutricional para la producción eficiente de ninfas de V estadio para ensayos biológicos. Materiales y métodos. Se determinaron los tiempos de desarrollo de l...

Volatile compound diversity and conserved alarm behaviour in Triatoma dimidiata.

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May-Concha, Irving; Rojas, Julio C; Cruz-López, Leopoldo; Ibarra-Cerdeña, Carlos N; Ramsey, Janine M

2015-02-06

Triatoma dimidiata (Latreille) is a key vector complex of Trypanosoma cruzi, etiologic agent of Chagas disease, as it spans North, Central, and South America. Although morphological and genetic studies clearly indicate existence of at least five clades within the species, there has been no robust or systematic revision, or appropriate nomenclature change for species within the complex. Three of the clades (haplogroups) are distributed in Mexico, and recent evidence attests to dispersal of clades across previously "presumed" monotypic geographic regions. Evidence of niche conservatism among sister species of this complex suggests that geographic dispersal is possible for non-sympatric populations, although no information is available on the behavioural aspects of potential interclade interactions, for instance whether differentiation of chemical signaling or response to these signals could impede communication among the haplogroups. Volatiles emitted by disturbed bugs, Brindley's (BGs), and metasternal (MGs) glands were identified using solid-phase micro-extraction (SPME) and gas chromatography coupled mass spectrometry (GC-MS). Volatile compounds emitted by BGs and MGs, and those secreted by disturbed nymphs and adults, of the three Mexican T. dimidiata haplogroups were tested for avoidance behaviour by conspecific nymphs and adults using an olfactometer. Triatoma dimidiata haplogroups all have three age-related alarm responses: absence of response by early stage nymphs, stage-specific response by 4-5th stage nymphs, and a shared 4-5th nymph and adult response to adult compounds. Disturbed bugs released 15 to 24 compounds depending on the haplogroup, among which were three pyrazines, the first report of these organoleptics in Triatominae. Isobutyric acid from BGs was the most abundant molecule in the response in all haplogroups, in addition to 15 (h1) to 21 (h2 and h3) MG compounds. Avoidance behaviour of disturbed bugs and volatiles emitted by BGs were haplogroup

Diversidad y distribución de acridios (Orthoptera: Acridoidea en pastizales del sur de la región pampeana, Argentina Diversity and distribution of grasshoppers (Orthoptera: Acridoidea in grasslands of the Southern Pampas region, Argentina

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Yanina Mariottini

2013-03-01

species of grasshoppers were collected, of which 21 belong to the family Acrididae. The subfamily Melanoplinae was the most diverse with eight species. The largest species richness was recorded in native grasslands (18. The different communities of grasshoppers had similar indices of evenness and dominance (p>0.05. Considering all plant communities, the average value of Shannon-Wiener index was 1.58±0.075. There was a positive correlation between evenness index and species richness (p<0.05. The diversity index H’ was different between plants communities (p<0.05, and it was higher in the disturbed grassland (1.75±0.096, p<0.05 than in the halophilous grasslands (1.34±0.12. Native and disturbed grasslands had a higher plant richness than halophilous grasslands and implanted pastures (p<0.05. There was a positive relationship between plant richness and grasshoppers species richness, and diversity of grasshoppers. According to the qualitative indices applied, the similitude between different grasshopper communities was higher than 60%. In general, the species that had a higher frequency of occurrence showed greater abundance and distribution. Covasacris pallidinota, Dichroplus elongatus, D. maculipennis, Borellia bruneri and B. pallid were the most widely distributed species, most of them (12 showed a restricted distribution and few (five an intermediate distribution.

Alberprosenia malheiroi Serra, Atzingen & Serra, 1987 (Hemiptera, Reduviidae: redescrição e bionomia Alberprosenia malheiroi Serra, Atzingen & Serra, 1987 (Hemiptera, Rediviidae: redescription and bionomics

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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.

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.

Estrutura de populações de Rhodnius neglectus Lent e Psammolestes tertius Lent & Jurberg (Hemiptera, Reduviidae em ninhos de pássaros (Furnariidae presentes na palmeira Mauritia flexuosa no Distrito Federal, Brasil Population structure of Rhodnius neglectus Lent and Psammolestes tertius Lent & Jurberg (Hemiptera, Reduviidae in bird nests (Furnariidae on Mauritia flexuosa palm trees in Federal District of Brazil

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Rodrigo Gurgel-Gonçalves

2007-03-01

Full Text Available Rhodnius neglectus Lent, 1954 {Rn}e Psammolestes tertius Lent & Jurberg, 1965 {Pt} são triatomíneos que ocorrem em ninhos de aves, principalmente da família Furnariidae. O ciclo biológico dessas espécies é conhecido em condições de laboratório, sendo poucos estudos em ecótopos silvestres. Para analisar a infestação e estrutura de populações de Rn e Pt em ninhos de aves presentes na palmeira Mauritia flexuosa Linnaeus, em duas estações climáticas do Brasil Central, foram amostradas 41 palmeiras com evidências de nidificação de Phacellodomus ruber Vieillot, 1817 (22 na estação chuvosa e 19 na estação seca em quatro áreas do Distrito Federal. Os insetos foram capturados usando-se coleta manual na copa da palmeira, identificados morfologicamente, separados por sexo e estádio ninfal. Fezes e glândulas salivares de Rn foram examinadas para verificar infecção por Trypanosoma cruzi Chagas, 1909 e/ou T. rangeli Tejera, 1920. Trinta e cinco palmeiras com ninhos de P. ruber estavam infestadas por Rn (85% e 22 por Pt (53%. 442 indivíduos foram coletados na estação seca (200 Rn e 242 Pt e 267 na estação chuvosa (136 Rn e 131 Pt. O único fator relacionado significativamente com a densidade de triatomíneos nas palmeiras foi a área. A estrutura etária das populações mostrou: a maior abundância de adultos nas populações de Pt, b maior abundância de machos em ambas as espécies e c presença de fêmeas ovipondo em ambas as estações. Nenhum dos 177 triatomíneos examinados estava infectado por T. cruzi ou T. rangeli. A estrutura etária das populações de Rn e Pt não diferiu significativamente entre as estações amostradas, indicando ausência de marcada sazonalidade para essas espécies.Rhodnius neglectus Lent, 1954 {Rn}and Psammolestes tertius Lent & Jurberg, 1965 {Pt} are triatomines that occur in bird nests, mainly furnarid nests. Their biological cycles are known in laboratory conditions and few studies were done in wild ecotopes. To analyze the infestation and population structure of Rn and Pt in bird nests on Mauritia flexuosa Linnaeus palm trees in two climatic seasons we sampled 41 palm trees with Phacellodomus ruber Vieillot, 1817 nests (22 in the wet season and 19 in the dry season in four areas of Distrito Federal. The insects were collected by manual capture in the crown of palms, identified, separated by sex and immature stages. Faeces and salivary glands of Rn were examined to verify Trypanosoma cruzi Chagas, 1909 and/or T. rangeli Tejera, 1920 infection. Thirty five palm trees with P. ruber nests were infested by Rn (85% and 22 by Pt (53%. 442 insects were collected in the dry season (200 Rn and 242 Pt and 267 in the wet season (136 Rn and 131 Pt. The area was the only factor related with triatomine density in palm trees. The population structure showed: a higher abundance of adults in Pt populations, b higher abundance of males in both species and, c females laying eggs in both seasons. Within the 177 insects examined none was infected by T. cruzi or T. rangeli. The population structure of Rn and Pt were not significantly different in the wet and the dry season, suggesting no seasonality reproduction.

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.

Feeding and defecation behavior of Triatoma rubida (Uhler, 1894) (Hemiptera: Reduviidae) under laboratory conditions, and its potential role as a vector of Chagas disease in Arizona, USA.

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Reisenman, Carolina E; Gregory, Teresa; Guerenstein, Pablo G; Hildebrand, John G

2011-10-01

Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host. We thus studied the feeding and defecation behaviors of the prevalent species in southern Arizona, Triatoma rubida. We found that whereas defecation during feeding was frequent in females (93%), it was very rare in immature stages (3%), and absent in males. Furthermore, more than half of the immature insects that exhibited multiple feeding bouts (62%) defecated during interruptions of feeding, i.e., while likely on or near the host. These results indicate that T. rubida potentially could transmit T. cruzi to humans.

LANDSCAPE CHANGES IN A LOWLAND IN BENIN: ECOLOGICAL IMPACT ON PESTS AND NATURAL ENEMIES.

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Boucher, A; Silvie, P; Menozzi, P; Adda, C; Auzoux, S; Jean, J; Huat, J

2015-01-01

impact on stem borers was hard to determine, even during the rainy season, due to their low abundance and the difficulty of identification. Predators (Reduviidae, Odonata) were found mainly in humid fallows and rice fields. Regarding our observations, we suggest the presence of alternate host crops such as okra during the dry season for rainy season crop pests. Moreover, fallows also had a real ecological role as a habitat resource for many guilds of insects (pollinators, pests, predators). The management of these landscape components should be the focus of a long-term study with the aim of enhancing pest management of rainy season crop pests.

Índice de defecación y éxito reproductivo de Triatoma maculata (Hemiptera:Reduviidaeen condiciones de laboratorio

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E Aldana

2004-12-01

Full Text Available Se estudió el comportamiento reproductivo y de defecación de Triatoma maculata (Erichson 1848alimentando artificialmente con sangre humana.Los estadios II y III mostraron mayor frecuencia de defecaciones (ID=0.6 n=40,el estadio V no alcanzó la diferenciación sexual, la fertilidad fue 55%(n=865,fecundidad 8 huevos/hembra/semana (n=26,22 días de desarrollo embrionario (n=477,longevidad de hembras 51 días (n=26,el tiempo intermuda aumenta progresivamente desde 35 días en el estadio I hasta 46 días en el estadio IV,el porcentaje de muda varió desde 0%en el estadio V hasta 63%en el estadio III,la mortalidad varió desde 8%en el estadio III hasta 100%en el estadio V (n=40.Los resultados del presente trabajo aportan evidencias que explican la menor capacidad vectorial y la baja densidad de T.maculata en el domicilio humano.Defecation index and reproductive success of Triatoma maculata (Hemiptera: Reduviidae under laboratory conditions.The reproductive and defecating behavior of Triatoma maculata (Erichson 1848was studied on animals from an university culture in Venezuela.This species does not reach the importance of Rhodnius prolixus Stal 1859 as Chagas disease vector in Venezuela.This study addressed the role of defecating frequency,an index of how dangerous the animals are for the human population,and its relationship with why T.maculata is a less important vector than R.prolixus .Human blood was fed to the insects through an artificial feeding device.The 2nd and 3rd instar nymphs defecated more frequently (Id=0.6,n=40,and our Vth instar nymphs did not complete sexual differentiation.Fertility was 55%(n=865and fecundity 8 eggs/female/week (n=26. Egg incubation lasted 22 days (n=477.Female longevity was 51 days (n=26.Intermould time grew progressively from 35 days for 1st to 40 days for 4th instar nymphs (n=40.Mould percentage varied from 0% for Vth to 63%for 3rd instar nymphs.Mortality varied from 8% for 3rd to 100% for Vth instar nymphs

Influência da temperatura e umidade no desenvolvimento ninfal de Rhodnius robustus Influence of temperature and humidity on the nymphal development of Rhodnius robustus

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Dayse da S Rocha

2001-08-01

Full Text Available OBJETIVO: Avaliar as diferenças significativas de desenvolvimento ninfal da espécie Rhodnius robustus Larrousse, 1927, submetida a diferentes condições de temperatura e umidade, que se encontra distribuída na região Norte do Brasil (Acre, Amazonas e Pará e na Colômbia, no Equador, no Peru e na Venezuela. MÉTODOS: Formaram-se três grupos de Rhodnius robustus, mantidos em diferentes condições de laboratório: 33/40 (33+/-1°C e 40+/-5% UR -- umidade relativa, 33/70 (33+/-1°C e 70+/-5% UR e 28/70 (28+/-1°C e 70+/-5% UR, para observar o período de incubação dos ovos, o desenvolvimento de cada estádio, os percentuais de mortalidade e os número de repastos realizados. RESULTADOS: O menor período médio de desenvolvimento ninfal foi observado no grupo 28/70 com as médias: 14,4; 17,3; 20,3; 22,8 e 40. O desenvolvimento embrionário apresentou diferenças significativas entre os tratamentos utilizados (pOBJECTIVE: To assess the significant differences in the nymphal development of the Rhodnius robustus Larrousse, 1927 under different temperatures and humidity conditions. This is a species found in the northern region of Brazil (states of Acre, Amazonas, and Pará, Colombia, Equator, Peru and Venezuela. METHODS: Three groups of triatominae were kept under the following laboratory conditions: 33/40 (33+1°C and 40+/-5% of relative humidity -- RH, 33/70 (33+/-1°C and 70+/-5% RH, and 28/70 (28+/-1°C and 70+/-5% RH. The incubation period of the eggs, developmental time of each stage, mortality percentage, number of bloodmeals, and the total amount of time from the egg hatching to adult ecdysis were observed. RESULTS: The shortest average time of nymphal development was observed in the 28/70 group, with following averages: 14.4, 17.3, 20.3, 22.8, and 40. Significant differences were observed in the embryonic development between the groups (p<0.01. For all groups, the number of bloodmeals had a gradual increase near the adult phase

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

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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

The process of lipid storage in insect oocytes: The involvement of β-chain of ATP synthase in lipophorin-mediated lipid transfer in the chagas' disease vector Panstrongylus megistus (Hemiptera: Reduviidae).

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Fruttero, Leonardo L; Leyria, Jimena; Ramos, Fabián O; Stariolo, Raúl; Settembrini, Beatriz P; Canavoso, Lilián E

2017-01-01

Lipophorin is the main lipoprotein in the hemolymph of insects. During vitellogenesis, lipophorin delivers its hydrophobic cargo to developing oocytes by its binding to non-endocytic receptors at the plasma membrane of the cells. In some species however, lipophorin may also be internalized to some extent, thus maximizing the storage of lipid resources in growing oocytes. The ectopic β chain of ATP synthase (β-ATPase) was recently described as a putative non-endocytic lipophorin receptor in the anterior midgut of the hematophagous insect Panstrongylus megistus. In the present work, females of this species at the vitellogenic stage of the reproductive cycle were employed to investigate the role of β-ATPase in the transfer of lipids to the ovarian tissue. Subcellular fractionation and western blot revealed the presence of β-ATPase in the microsomal membranes of the ovarian tissue, suggesting its localization in the plasma membrane. Immunofluorescence assays showed partial co-localization of β-ATPase and lipophorin in the membrane of oocytes as well as in the basal domain of the follicular epithelial cells. Ligand blotting and co-immunoprecipitation approaches confirmed the interaction between lipophorin and β-ATPase. In vivo experiments with an anti-β-ATPase antibody injected to block such an interaction demonstrated that the antibody significantly impaired the transfer of fatty acids from lipophorin to the oocyte. However, the endocytic pathway of lipophorin was not affected. On the other hand, partial inhibition of ATP synthase activity did not modify the transfer of lipids from lipophorin to oocytes. When the assays were performed at 4°C to diminish endocytosis, the results showed that the antibody interfered with lipophorin binding to the oocyte plasma membrane as well as with the transfer of fatty acids from the lipoprotein to the oocyte. The findings strongly support that β-ATPase plays a role as a docking lipophorin receptor at the ovary of P. megistus, similarly to its function in the midgut of such a vector. In addition, the role of β-ATPase as a docking receptor seems to be independent of the enzymatic ATP synthase activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Cardiomiopatía de Chagas.

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Fernando Rosas A.

2000-08-01

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La cardiomiopatía de Chagas es la causa más frecuente de cardiomiopatía en América Latina. Se constituye en la cuarta enfermedad parasitaria del continente, y es uno de los mayores problemas de salud pública en Colombia estimándose que existen 1.200.000 personas infectadas y que de éstos proba-blemente 25% desarrollaran una miocardiopatia crónica.

En nuestro país pocas series clínicas han sido descritas, generalmente asociadas a falla cardíaca secundaria a una cardiomiopatía dilatada. El propósito de este trabajo es presentar una reseña histórica de la enfermedad en la que se incluyen los primeros trabajos clínicos desarrollados en nuestro medio. Así mismo, algunos aspectos de la fisiopatología y de la evolución clínica. Finalmente presentaremos la reciente experiencia acumulada en nuestro país en este campo por diferentes investigadores.

Reseña Histórica
En el año 1909 fue publicado el artículo original del Dr. Carlos Chagas, titulado “Nueva Trypanosomiasis Humana: estudios sobre la morfología y el ciclo evolutivo del Schizotrypanum Cruzi, agente etiológico de una nueva entidad mórbida en el hombre” (1. En él se describe como el Dr. Chagas, fue encomendado en 1907, por el Dr. Oswaldo Cruz (Director del instituto que posteriormente llevó su nombre, para ejecutar una campaña antipalúdica en los servicios de construcción de ferrocarriles en el norte del estado de Minas Gerais.

En esa zona conoció la existencia de una hematófago denominado por los campesinos como “Barbeiro”, llamado así por que su picadura se localizaba usualmente en el rostro y era poco sintomática. El insecto habitaba en domicilios humanos, atacaba al hombre en la noche (después de apagar las luces, se ocultaba durante el día en las paredes y en los techos de las casas construidas en bahareque y paja. El hematófago fue identificado como perteneciente a la familia Reduviidae. Algunos de los

Estudo pareado da cardiopatia chagásica no Rio Grande do Sul, Brasil: comportamento das alterações eletrocardiográficas em função da cor Matched study of Chagas cardiopaty in southerm Brazil: ECG alterations according to skin color

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Giovanni Baruffa

1987-09-01

suggestive of Chagas cardiopathy were more common among blacks with positive serological reactions. Blacks with seronegative reactions had more frequent ECG changes which were of increased severity, than those of whites with negative reactions. The increased prevalence and severity of ECG changes among black might be attributed to several factors, including: higher levels of poverty, leading to strenuous working conditions; poorer housing quality facilitating infestations by triatominae; inadequate feeding habits. In addition, the increased levels of arterial tension found among the blacks, might be associated with possible racial factors, in collaborating to increase the likelihood of myocardial lesions.

Enfermedad de Chagas o Tripanosomiasis Americana.

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Felipe Guhl

2000-08-01

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Situación Actual de Colombia.

La enfermedad de Chagas o tripanosomiasis americana es una enfermedad parasitaria crónica causada por un protozoario flagelado el Trypanosoma cruzi, descrito por primera vez por Carlos Chagas, médico brasileño, a comienzos de este siglo y en su honor se denominó la enfermedad que lleva su nombre.

Este parásito normalmente se transmite al ser humano a través de insectos triatomíneos estrictamente hematófagos de la familia Reduviidae, en el momento en que perforan la piel para succionar la sangre que los alimenta.

Sin embargo, no se inocula directamente por intermedio de las estructuras bucales del insecto en el momento de la picadura como en el caso de las tripanosomiasis africanas, si no que se deposita pasivamente en la piel a través de las heces del insecto, penetrando en el cuerpo por la herida que causa la picadura u otras abrasiones de la piel o de la mucosa. El T. cruzi, también puede transmitirse por infección congénita, por transfusión de sangre contaminada o por el transplante de órganos contaminados. El ciclo vital del parásito es largo y complejo y su desarrollo tiene varias etapas, tanto en el vector triatomineo como en el huésped vertebrado .

La Enfermedad de Chagas constituye una amenaza permanente para casi la cuarta parte de toda la población de América Latina. Si bien la enfermedad se encuentra presente en toda América Central y del Sur, sus manifestaciones y características epidemiológicas son altamente variables entre una y otra zona endémica. Existe una gran diversidad en las tasas de prevalencia, formas de transmisión, características parasitarias, patología clínica, vectores y reservorios.

Más que cualquier otra enfermedad parasitaria, la enfermedad de Chagas se relaciona con el desarrollo económico y social de la población: los insectos triatomineos y las enfermedades que ellos transmiten existirán mientras en

Relevancia de la infección natural por Trypanosoma cruzi en triatominos selváticos provenientes de seis municipios de Santander, Colombia

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Sergio Gómez

2016-06-01

Full Text Available Introducción: La enfermedad de Chagas es causada por el parásito Trypanosoma cruzi y es transmitida principalmente a través de heces contaminadas del insecto vector (Triatominae. Otras formas de transmisión (vía oral han reemergido. Recientemente, en diferentes municipios de Santander se han reportado microbrotes de Chagas agudo de probable transmisión oral que podrían estar asociados con la presencia de reservorios y triatominos selváticos infectados naturalmente que ingresan esporádicamente a las viviendas desde ecotopos peridomésticos y contaminan los alimentos. Algunas especies de triatominos han sido reportadas en la región, sin embargo se desconoce, la tasa de infección natural y las unidades discretas de tipificación o DTUs de T. cruzi (denominadas TcI a TcVI presentes en estos vectores. Objetivo: Identificar la presencia de infección por T. cruzi y genotipificar el parásito infectante en triatominos selváticos capturados en seis municipios del departamento de Santander, Colombia. Materiales y métodos: Los triatominos fueron recolectados mediante trampas de luz Shannon y vigilancia activa por la comunidad y autoridades sanitarias, en el intradomicilio y extradomicilio de localidades urbanas y rurales de los municipios de Bucaramanga, Floridablanca, Capitanejo, San Vicente de Chucurí, Lebrija y Rionegro, durante el periodo 2011-2015. Los insectos fueron identificados siguiendo las claves de Lent & Wygodzinsky (1979. El contenido intestinal de cada insecto fue obtenido por masaje abdominal y aislado en una suspensión de tampón fosfato salino. Una alícuota se utilizó para evaluación directa y otra fue almacenada a -20 ºC hasta su uso. La tasa de infección (TI se estableció por examen directo del contenido intestinal de los vectores para determinar la presencia del parásito, con confirmación mediante la amplificación de ADN satélite de T. cruzi (satADN, utilizando el ADN extraído por el método salting out. La

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

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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.