Aedes albopictus Skuse (Diptera: Culicidae) was tested for resistance to permethrin, bifenthrin, and malathion using Centers for Disease Control and Prevention (CDC) bottle bioassays and topical toxicology assays on adults and larval bioassays. Eggs were collected from 3 locations across St. Johns C...
Kalan, Katja; Ivovic, Vladimir; Glasnovic, Peter; Buzan, Elena
In Slovenia, two invasive mosquito species are present, Aedes albopictus (Skuse, 1895) (Diptera: Culicidae) and Aedes japonicus (Theobald, 1901) (Diptera: Culicidae). In this study, we examined their actual distribution and suitable habitats for new colonizations. Data from survey of species presence in 2013 and 2015, bioclimatic variables and altitude were used for the construction of predictive maps. We produced various models in Maxent software and tested two bioclimatic variable sets, WorldClim and CHELSA. For the variable selection of A. albopictus modeling we used statistical and expert knowledge-based approach, whereas for A. j. japonicus we used only a statistically based approach. The best performing models for both species were chosen according to AIC score-based evaluation. In 2 yr of sampling, A. albopictus was largely confined to the western half of Slovenia, whereas A. j. japonicus spread significantly and can be considered as an established species in a large part of the country. Comparison of models with WorldClim and CHELSA variables for both species showed models with CHELSA variables as a better tool for prediction. Finally, we validated the models performance in predicting distribution of species according to collected field data. Our study confirms that both species are co-occurring and are sympatric in a large part of the country area. The tested models could be used for future prevention of invasive mosquitoes spreading in other countries with similar bioclimatic conditions. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: email@example.com.
Chan, Hiang Hao; Zairi, Jaal
Insecticide resistance has become a serious issue in vector management programs. Information on insecticidal resistance and its associated mechanisms is important for successful insecticide resistance management. The selection of a colony of permethrin-resistant Aedes albopictus (Skuse) (Diptera: Culicidae), originating from Penang Island, Malaysia, yielded high larval-specific resistance to permethrin and cross-resistance to deltamethrin. Synergism assays showed that the major mechanism underlying this resistance involves cytochrome P450 monooxygenase. The resistance is autosomal, polygenically inherited and incompletely dominant (D = 0.26). Resistant larvae were reared under different conditions to assess the fitness costs. Under high larval density, larval development time of the resistant SGI strain was significantly longer than the susceptible VCRU strain. In both high- and low-density conditions SGI showed a lower rate of emergence and survival compared with the VCRU strain. Resistant larvae were more susceptible to predation by Toxorhynchites splendens (Wiedemann) (Diptera: Culicidae) larvae. The body size of SGI females reared under high-density conditions was larger compared with females of the susceptible strain. SGI females survived longer when starved than did VCRU females. The energy reserve upon eclosion was positively correlated with the size of the adults.
of adult mosquitoes, with humans acting as baits, was employed for the study. Environmental inspection and collection of larvae in the water-holding containers around the buildings were used to study the breeding sites of the mosquitoes. A total of 73 adult mosquitoes, made up of Aedes albopictus (76.71%) and A. aegypti ...
Lacour, Guillaume; Chanaud, Lionel; L'Ambert, Grégory; Hance, Thierry
In temperate areas, population dynamics of the invasive Asian tiger mosquito Aedes albopictus are strongly affected by winter. The work we present here analyzes the adaptive synchronization of the diapause process in the wintry generation of A. albopictus, where the egg stage is exposed to adverse winter conditions. The seasonal pattern of egg laying activity of a French Mediterranean population of the Asian tiger mosquito was monitored weekly for 2 years with ovitraps. The field diapause incidence and the critical photoperiod (CPP, i.e. the maternal day length inducing diapause in 50% of the eggs), were determined by hatching experiments on the collected eggs. The period of diapause termination was estimated by a field survey of the first hatchings for both years. The CPP is equal to 13.5 hours of light and occurs in the field on the 25th of August. Thus, it is on September 11th, 17 days after the CPP, that 50% of the eggs are in a prediapause stage in the field. The egg diapause rate increases rapidly during September, whereas the mean number of eggs laid decreases sharply after mid-September. Surprisingly, after having reached a peak of 95% at the end of September, from mid-October the diapause incidence declined and stayed below 50%. Indeed, both years the diapause initiates before the rapid decrease of the environmental temperature. This leaves a sufficient period of time to the complete development of one generation of A. albopictus with effective induction of diapause in the laid eggs. The very first larvae hatched were sampled both years in the first half of March. With 20 to 26 weeks in the egg stage and about 7 weeks in the larval stages, the first annual generation spends a long time in immature stages. On a practical point of view, this long development time represents a wide window for eggs and larvae control in early spring.
Mogi, M; Armbruster, P A; Tuno, N; Aranda, C; Yong, H S
We compared climatic distribution ranges between Aedes albopictus (Skuse) (Diptera: Culicidae) and the five wild (nondomesticated) species of Albopictus Subgroup of Scutellaris Group of Aedes (Stegomyia) in southern Asia. Distribution sites of the wild species concentrate in seasonal forest and savannah climate zones in India, Indochina, and southern China. The distribution of Ae. albopictus is broader than the wild species under 1) tropical rain-forest climate, 2) steppe and temperate savannah climate, and 3) continental climate with large seasonal temperature variation (hot summer and cold winter) at temperate lowlands (northernmost sites 40°N in Ae. albopictus vs 32°N in the wild species). However, the distribution of Ae. albopictus is more limited at tropical and subtropical highlands where the climate is cool but less continental (small seasonal variation, mild summer, and winter). We discuss a possibility that the broader climate ranges of Ae. albopictus are ecological or eco-evolutionary consequences of adaptation to human habitats. We also propose a general scenario for the origin, dispersal, and adaptation of Ae. albopictus in Asia as a hypothesis for future research. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: firstname.lastname@example.org.
Johnson, Tammi L; Haque, Ubydul; Monaghan, Andrew J; Eisen, Lars; Hahn, Micah B; Hayden, Mary H; Savage, Harry M; McAllister, Janet; Mutebi, John-Paul; Eisen, Rebecca J
The mosquitoes Aedes (Stegomyia) aegypti (L.)(Diptera:Culicidae) and Ae. (Stegomyia) albopictus (Skuse) (Diptera:Culicidae) transmit dengue, chikungunya, and Zika viruses and represent a growing public health threat in parts of the United States where they are established. To complement existing mosquito presence records based on discontinuous, non-systematic surveillance efforts, we developed county-scale environmental suitability maps for both species using maximum entropy modeling to fit climatic variables to county presence records from 1960-2016 in the contiguous United States. The predictive models for Ae. aegypti and Ae. albopictus had an overall accuracy of 0.84 and 0.85, respectively. Cumulative growing degree days (GDDs) during the winter months, an indicator of overall warmth, was the most important predictive variable for both species and was positively associated with environmental suitability. The number (percentage) of counties classified as environmentally suitable, based on models with 90 or 99% sensitivity, ranged from 1,443 (46%) to 2,209 (71%) for Ae. aegypti and from 1,726 (55%) to 2,329 (75%) for Ae. albopictus. Increasing model sensitivity results in more counties classified as suitable, at least for summer survival, from which there are no mosquito records. We anticipate that Ae. aegypti and Ae. albopictus will be found more commonly in counties classified as suitable based on the lower 90% sensitivity threshold compared with the higher 99% threshold. Counties predicted suitable with 90% sensitivity should therefore be a top priority for expanded mosquito surveillance efforts while still keeping in mind that Ae. aegypti and Ae. albopictus may be introduced, via accidental transport of eggs or immatures, and potentially proliferate during the warmest part of the year anywhere within the geographic areas delineated by the 99% sensitivity model. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work
Richards, Stephanie L; Ponnusamy, Loganathan; Unnasch, Thomas R; Hassan, Hassan K; Apperson, Charles S
Aedes albopictus (Skuse) (Diptera: Culicidae) is a major nuisance mosquito and a potential arbovirus vector. The host-feeding patterns of Ae. albopictus were investigated during the 2002 and 2003 mosquito seasons in suburban neighborhoods in Wake County, Raleigh, NC. Hosts of blood-fed Ae. albopictus (n = 1,094) were identified with an indirect enzyme-linked immunosorbent assay, by using antisera made in New Zealand White rabbits to the sera of animals that would commonly occur in peridomestic habitats. Ae. albopictus fed predominantly on mammalian hosts (83%). Common mammalian hosts included humans (24%), cats (21%), and dogs (14%). However, a notable proportion (7%) of bloodmeals also was taken from avian hosts. Some bloodmeals taken from birds were identified to species by a polymerase chain reaction-heteroduplex assay (PCR-HDA). Ae. albopictus fed predominantly on chickens and a northern cardinal. PCR-HDA failed to produce detectable products for 29 (58%) of 50 bloodmeals for which DNA had been amplified, indicating that these mosquitoes took mixed bloodmeals from avian and nonavian hosts. Ae. albopictus preference for humans, dogs, and cats was determined by calculating host-feeding indices for the three host pairs based on the proportion of host specific blood-fed mosquitoes collected in relation to the number of specific hosts per residence as established by a door-to-door survey conducted in 2003. Estimates of the average amount of time that residents and their pets (cats and dogs) spent out of doors were obtained. Host-feeding indices based only on host abundance indicated that Ae. albopictus was more likely to feed on domestic animals. However, when feeding indices were time-weighted, Ae. albopictus fed preferentially upon humans. Ae. albopictus blood feeding on humans was investigated using a STR/PCR-DNA profiling technique that involved amplification of three short tandem repeats loci. Of 40 human bloodmeals, 32 (80%) were from a single human, whereas
Baldacchino, Frédéric; Arnoldi, Daniele; Lapère, Charlotte; Rosà, Roberto; Montarsi, Fabrizio; Capelli, Gioia; Rizzoli, Annapaola
Aedes (Hulecoeteomyia) koreicus (Edwards) and Aedes (Stegomyia) albopictus (Skuse) are two invasive mosquito species well established in northeastern Italy, and these two species may co-occur in artificial larval habitats such as tires, buckets, drums, and catch basins. Because Ae. albopictus has been shown experimentally to be a superior competitor to several mosquito species, we investigated larval competition between Ae. koreicus and Ae. albopictus using two diet levels (low level and high level) and 10 Ae. albopictus: Ae. koreicus density combination levels (30:0, 60:0, 15:15, 30:30, 10:20, 20:10, 20:40, 40:20, 0:60, and 0:30). A multivariate analysis (MANOVA) demonstrated a significant effect of the density combination on Ae. koreicus survivorship, female development time, and female wing length considered simultaneously in low-level diet and high-level diet treatments. Pairwise comparisons across low-level diet treatments showed a significant reduction of Ae. koreicus survivorship in 20:10 combination treatments (i.e. 20 Ae. albopictus and 10 Ae. koreicus larvae) compared to 10:20, 20:40, and 30:30 combination treatments, while no difference was detected for Ae. albopictus between density combination treatments. Furthermore, Ae. albopictus developed faster than Ae. koreicus regardless of diet and density combination treatments. Our results show weak larval competition between Ae. koreicus and Ae. albopictus with a slight advantage of the latter species. On the other hand, the presence of Ae. albopictus seems to favor the emergence of larger Ae. koreicus females. We suggest that factors such as habitats preferences or seasonal distributions may be determinant for the invasion success of Ae. koreicus. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Unlu, Isik; Williams, Gregory M; Rochlin, Ilia; Suman, Devi; Wang, Yi; Chandel, Kshitij; Gaugler, Randy
Mosquito control programs in the United States are still searching for best management practices to control the Asian tiger mosquito, Aedes albopictus (Skuse; Diptera: Culicidae). Most intervention methods for this species are either labor intensive (e.g., source reduction) or short-term (e.g., ultra-low-volume adulticiding). We investigated the effectiveness of barrier spray pesticide applications within urban and suburban residential yards in New Jersey as a control strategy using a before-after-control-impact (BACI) approach. Applications of Demand CSR pyrethroid (9.7% AI lambda-cyhalothrin) only or combined Demand CSR and Archer IGR insect growth regulator (1.3% AI pyriproxyfen) applications resulted in significant and similar decreases in adult mosquito abundance post-treatment ranging from 78 to 74% respectively, compared with the untreated control. Both insecticides exceeded the 70% reduction threshold considered as effective for Ae. albopictus control for 2 to 4 wk. However, applications of Archer IGR alone did not reduce adult mosquito abundance. The field study results were supported by laboratory no-choice bioassays using treated leaf foliage. Our study is the first data driven evidence of the residual efficacy of barrier pesticide applications in New Jersey with lambda-cyhalothrin that provided significant reductions in adult Ae. albopictus populations for an extended duration.
Kamgang, Basile; Nchoutpouen, Elysée; Simard, Frédéric; Paupy, Christophe
Abstract Background The invasive mosquito Aedes albopictus is often considered a poor vector of human pathogens, owing to its catholic feeding behavior. However, it was recently incriminated as a major vector in several Chikungunya epidemics, outside of its native range. Here we assessed two key elements of feeding behavior by Ae. albopictus females in Yaoundé, Cameroon, Central Africa. Host preference was explored and the human-biting activity of females was monitored over 24 h to determine ...
Cuéllar-Jiménez, María Elena; Velásquez-Escobar, Olga Lucía; González-Obando, Ranulfo; Morales-Reichmann, Carlos Andrés
Aedes albopictus is the second most important dengue virus vector in the Asian southeast after Aedes aegypti. Its entrance into the Americas occurred in 1985, and laboratory studies performed show its potential as a vector in this continent as well. In Colombia, this species has been reported in Leticia (Amazonas) in 1998 and Buenaventura (Valle del Cauca) in 2001. The latest discoveries show that this mosquito continues to advance toward the country's interior. To inform that the presence of A. albopictus is documented in the city of Cali, Valle del Cauca, Colombia. Since 2002, weekly sampling has been performed using larval traps located at seventeen stations. The identification of the A. albopictus species, was carried out in the Unidad de Entomología, Laboratorio de Salud Pública Departamental. These identifications were confirmed in the Entomology Laboratory at Universidad del Valle and the National Institute of Health in Bogotá. From April to June of 2006, larvae of A. albopictus were found in six sampling stations located between northwest and northeast of Cali, one of them in the suburban area of the Yumbo city. The control of A. aegypti and A. albopictus must be integrated into a single program. The surveillance in the cities and nearest departments must be intensified with the objective of limiting the advancement of A. albopictus.
Full Text Available Abstract Background The invasive mosquito Aedes albopictus is often considered a poor vector of human pathogens, owing to its catholic feeding behavior. However, it was recently incriminated as a major vector in several Chikungunya epidemics, outside of its native range. Here we assessed two key elements of feeding behavior by Ae. albopictus females in Yaoundé, Cameroon, Central Africa. Host preference was explored and the human-biting activity of females was monitored over 24 h to determine periods of maximum bite exposure. Findings Analysis of ingested blood in outdoor-resting females showed that Ae. albopictus preferentially fed on humans rather than on available domestic animals (95% of the blood meals contained human blood. Our results further showed that Ae. albopictus is a day-biting species in Yaoundé, with a main peak of activity in the late afternoon. Conclusion This is the first report on the feeding behavior of Ae. albopictus in Central Africa. The species is highly aggressive to humans and might therefore be involved in human-human virus transmission in this setting.
Kamgang, Basile; Nchoutpouen, Elysée; Simard, Frédéric; Paupy, Christophe
The invasive mosquito Aedes albopictus is often considered a poor vector of human pathogens, owing to its catholic feeding behavior. However, it was recently incriminated as a major vector in several Chikungunya epidemics, outside of its native range. Here we assessed two key elements of feeding behavior by Ae. albopictus females in Yaoundé, Cameroon, Central Africa. Host preference was explored and the human-biting activity of females was monitored over 24 h to determine periods of maximum bite exposure. Analysis of ingested blood in outdoor-resting females showed that Ae. albopictus preferentially fed on humans rather than on available domestic animals (95% of the blood meals contained human blood). Our results further showed that Ae. albopictus is a day-biting species in Yaoundé, with a main peak of activity in the late afternoon. This is the first report on the feeding behavior of Ae. albopictus in Central Africa. The species is highly aggressive to humans and might therefore be involved in human-human virus transmission in this setting.
Jackson, Bryan T; Brewster, Carlyle C; Paulson, Sally L
The effects of La Crosse virus (LACV) infection on blood feeding behavior in Aedes triseriatus (Say) and Aedes albopictus (Skuse) were investigated in the laboratory by measuring the size of the bloodmeal imbibed and the extent of refeeding by virus-infected and uninfected mosquitoes. LACV-infected Ae. triseriatus and Ae. albopictus took significantly less blood compared with uninfected mosquitoes. Twice as many virus-infected Ae. triseriatus mosquitoes refed compared with uninfected individuals (18 vs. 9%; P < 0.05); however, virus infection had no significant effect on the refeeding rate of Ae. albopictus. Reduction in bloodmeal size followed by an increased avidity for refeeding may lead to enhanced horizontal transmission of the LACV by its principal vector, Ae. triseriatus.
Ruiling, Zhang; Peien, Leng; Xuejun, Wang; Zhong, Zhang
Aedes albopictus is one of the most invasive species, which can carry Dengue virus, Yellow fever virus and more than twenty arboviruses. Based on mitochondrial gene cytochrome c oxidase I (COI) and samples collected from 17 populations, we investigated the molecular character and genetic diversity of Ae. albopictus from China. Altogether, 25 haplotypes were detected, including 10 shared haplotypes and 15 private haplotypes. H1 was the dominant haplotype, which is widely distributed in 13 populations. Tajima'D value of most populations was significantly negative, demonstrating that populations experienced rapid range expansion recently. Most haplotypes clustered together both in phylogenetic and median-joining network analysis without clear phylogeographic patterns. However, neutrality tests revealed shallow divergences among Hainan and Guangxi with other populations (0.15599 ≤ F ST ≤ 0.75858), which probably due to interrupted gene flow, caused by geographical isolations. In conclusion, Ae. albopictus populations showed low genetic diversity in China.
Ngoagouni, Carine; Kamgang, Basile; Nakouné, Emmanuel; Paupy, Chistophe; Kazanji, Mirdad
Aedes albopictus, a mosquito native to Asia, has invaded all five continents during the past three decades. It was reported in central Africa in the 2000s, first in Cameroon, and, since then, has colonised almost all countries of the region. The species, originally considered a secondary vector of dengue viruses, has been showed to play a major role in transmission of chikungunya virus in numerous countries, including in the central African region. We review the current spread of Ae. albopictus in central Africa, its larval ecology and its impact on indigenous species such as Ae. aegypti. We explore the potential of Ae. albopictus to affect the epidemiology of emerging or re-emerging arboviruses and discuss the conventional means for its control, while emphasizing the importance of data on its susceptibility to insecticides to cope with potential outbreaks.
Qualls, Whitney A; Xue, Rui De; Beier, John C; Müller, Günter C
The international trade of lucky bamboo (Dracaena sanderiana [Asparagaceae]) is responsible for certain introductions of the exotic species Aedes albopictus (Skuse) in California and the Netherlands. Understanding the association of this species with lucky bamboo and other ornamental plants is important from a public health standpoint. The aim of this study was to investigate the importance of indoor ornamental plants as sugar sources for adult A. albopictus. If exposed to D. sanderiana, bromeliad (Guzmania spp. hybrid [Bromeliaceae]), Moses-in-the-cradle (Rhoeo spathacea [Commelinaceae]), 10 % sucrose solution, and a negative water control as the only nutrient source, adult female A. albopictus mean survival time was 12, 7, 6, 15, and 4 days, respectively. Mean survival times for adult males were not significantly different (P > 0.05) from the females and were 10, 7, 6, 14, and 3 days, respectively. Combined male and female survival times were not significantly different on lucky bamboo compared to survival times on a 10 % sucrose control. Based on our findings, A. albopictus can readily survive long enough to complete a gonotrophic cycle and potentially complete the extrinsic incubation period for many arboviruses when only provided access to lucky bamboo plants or possibly other common ornamentals. Vector control professionals should be aware of potential in-home infestations and public health concerns associated with mosquito breeding and plant tissue feeding on ornamental plants.
Cianci, D.; Hartemink, N.; Zeimes, C.B.; Vanwambeke, S.O.; Ienco, A.; Caputo, B.
Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat
The invasion and range expansion of Aedes albopictus (Skuse) in North America represents an outstanding opportunity to study processes of invasion, range expansion, and climatic adaptation. Furthermore, knowledge obtained from such research is relevant to developing novel strategies to control this important vector species. Substantial evidence indicates that the photoperiodic diapause response is an important adaptation to climatic variation across the range of Ae. albopictus in North America. Photoperiodic diapause is a key determinant of abundance in both space and time, and the timing of entry into and exit out of diapause strongly affects seasonal population dynamics and thus the potential for arbovirus transmission. Emerging genomic technologies are making it possible to develop high-resolution, genome-wide genetic markers that can be used for genetic mapping of traits relevant to disease transmission and phylogeographic studies to elucidate invasion history. Recent work using next-generation sequencing technologies (e.g., RNA-seq), combined with physiological experiments, has provided extensive insight into the transcriptional basis of the diapause response in Ae. albopictus. Applying this knowledge to identify novel targets for vector control represents an important future challenge. Finally, recent studies have begun to identify traits other than diapause that are affected by photoperiodism. Extending this work to identify additional traits influenced by photoperiod should produce important insights into the seasonal biology of Ae. albopictus. PMID:27354438
Osório, Hugo Costa; Zé-Zé, Líbia; Neto, Maria; Silva, Sílvia; Marques, Fátima; Silva, Ana Sofia; Alves, Maria João
The Asian tiger mosquito Aedes albopictus is an invasive mosquito originating from the Asia-Pacific region. This species is of major concern to public and veterinary health because of its vector role in the transmission of several pathogens, such as chikungunya, dengue, and Zika viruses. In Portugal, a National Vector Surveillance Network (REde de VIgilância de VEctores—REVIVE) is responsible for the surveillance of autochthonous, but also invasive, mosquito species at points of entry, such as airports, ports, storage areas, and specific border regions with Spain. At these locations, networks of mosquito traps are set and maintained under surveillance throughout the year. In September 2017, Ae. albopictus was detected for the first time in a tyre company located in the North of Portugal. Molecular typing was performed, and a preliminary phylogenetic analysis indicated a high similarity with sequences of Ae. albopictus collected in Europe. A prompt surveillance response was locally implemented to determine its dispersal and abundance, and adult mosquitoes were screened for the presence of arboviral RNA. A total of 103 specimens, 52 immatures and 51 adults, were collected. No pathogenic viruses were detected. Despite the obtained results suggest low abundance of the population locally introduced, the risk of dispersal and potential establishment of Ae. albopictus in Portugal has raised concern for autochthonous mosquito-borne disease outbreaks. PMID:29690531
Davis, Timothy J; Kline, Daniel L; Kaufman, Phillip E
Aedes albopictus (Skuse) is a container-breeding mosquito commonly found in residential areas of its range in the United States. Mosquitoes are known to utilize flowering plants for sugar acquisition. Limited information is known about the influences on oviposition site selection, outside of container size. Residential areas are often landscaped with a variety of flowering plants and are known to provide numerous sizes of potential larval developmental sites for container-breeding mosqutioes. Through screened enclosure and field studies, the oviposition preference of Ae. albopictus for containers of three selected sizes (473, 946 and 1,892 ml) and the influence of flowering butterfly bush (Buddleja davidii Franchett cultivar 'Guinevere') plants were examined. Our results document that significantly more eggs were oviposited in the largest containers. Additionally, significantly more eggs were oviposited in containers adjacent to flowering butterfly bushes than in those without a flowering butterfly bush. Finally, our results document that flowering butterfly bushes exerted greater influence over Ae. albopictus oviposition decisions than did container size. Our findings can be applied to several aspects of Ae. albopictus surveillance and control.
Hugo Costa Osório
Full Text Available The Asian tiger mosquito Aedes albopictus is an invasive mosquito originating from the Asia-Pacific region. This species is of major concern to public and veterinary health because of its vector role in the transmission of several pathogens, such as chikungunya, dengue, and Zika viruses. In Portugal, a National Vector Surveillance Network (REde de VIgilância de VEctores—REVIVE is responsible for the surveillance of autochthonous, but also invasive, mosquito species at points of entry, such as airports, ports, storage areas, and specific border regions with Spain. At these locations, networks of mosquito traps are set and maintained under surveillance throughout the year. In September 2017, Ae. albopictus was detected for the first time in a tyre company located in the North of Portugal. Molecular typing was performed, and a preliminary phylogenetic analysis indicated a high similarity with sequences of Ae. albopictus collected in Europe. A prompt surveillance response was locally implemented to determine its dispersal and abundance, and adult mosquitoes were screened for the presence of arboviral RNA. A total of 103 specimens, 52 immatures and 51 adults, were collected. No pathogenic viruses were detected. Despite the obtained results suggest low abundance of the population locally introduced, the risk of dispersal and potential establishment of Ae. albopictus in Portugal has raised concern for autochthonous mosquito-borne disease outbreaks.
Bartlett-Healy, Kristen; Unlu, Isik; Obenauer, Peter; Hughes, Tony; Healy, Sean; Crepeau, Taryn; Farajollahi, Ary; Kesavaraju, Banu; Fonseca, Dina; Schoeler, George; Gaugler, Randy; Strickman, Daniel
Aedes albopictus (Skuse) and Ae. japonicus (Theobald) are important container-inhabiting mosquitoes that transmit disease agents, outcompete native species, and continue to expand their range in the United States. Both species deposit eggs in natural and artificial containers and thrive in peridomestic environments. The goal of our study was to examine the types and characteristics of containers that are most productive for these species in the northeastern United States. In total, 306 containers were sampled in urban, suburban, and rural areas of New Jersey. Multiple biotic and abiotic factors were recorded in an attempt to identify variables associated with the productivity of each species. Based on pupal abundance and density of container types, results showed that tires, trash cans, and planter dishes were the most important containers for Ae. albopictus, while planter dishes were the most important containers for Ae. japonicus. Container color (black and gray), material (rubber), and type (tires) were correlated with species presence for Ae. albopictus and Ae. japonicus. These factors may play a role in the selection of oviposition sites by female mosquitoes or in the survival of their progeny. Differences in species composition and abundance were detected between areas classified as urban, suburban, and rural. In urban and suburban areas, Ae. albopictus was more abundant in container habitats than Ae. japonicus; however, Ae. japonicus was more abundant in rural areas, and when water temperatures were below 14 degrees C. Our results suggest many variables can influence the presence of Ae. albopictus and Ae. japonicus in container habitats in northeastern United States.
Chou, Lee Yiung; Dykes, Gary A; Wilson, Robyn F; Clarke, Charles M
Nepenthes pitcher plants are colonized by a variety of specialized arthropods. As Aedes mosquitoes are container breeders, Nepenthes pitchers are a potential candidate oviposition site for vector species, such as Aedes aegypti (L.) and Aedes albopictus (Skuse). However, Aedes spp. are not commonly encountered in Nepenthes pitchers, and the environment inside the pitchers of some species is lethal to them. One exception is Nepenthes ampullaria Jack, whose pitchers are known to be colonized by Ae. albopictus on very rare occasions. Given that Ae. albopictus larvae can survive in N. ampullaria pitcher fluids, we sought to determine why pitcher colonization is rare, testing the hypothesis that gravid Aedes mosquitoes are deterred from ovipositing into container habitats that have similar characteristics to N. ampullaria pitchers. Using plastic ovitraps of different sizes, colors, and with different types of fluids (based on the characteristics of N. ampullaria pitchers), we compared oviposition rates by Aedes mosquitoes in urban and rural areas within the geographical range of N. ampullaria near Kuala Lumpur, Malaysia. Ovitraps that were black and large (>250-ml capacity) accumulated significantly more eggs than ovitraps that were smaller, or green in color. In terms of size and color, small, green ovitraps are analogous to N. ampullaria pitchers, indicating that these pitchers are not particularly attractive to gravid Ae. albopictus. Although Aedes spp. are capable of colonizing N. ampullaria pitchers, the pitchers are relatively unattractive to gravid females and do not represent a significant habitat for larvae of dengue vectors at present. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Carvajal, José Joaquín; Honorio, Nildimar Alves; Díaz, Silvia Patricia; Ruiz, Edinso Rafael; Asprilla, Jimmy; Ardila, Susanne; Parra-Henao, Gabriel
Aedes albopictus is widely distributed around the world. Its introduction to the Americas occurred in 1985 and it is considered a potential vector of dengue viruses and one of the principal vectors of chikungunya virus. In Colombia, this species was reported for the first time in Leticia (Amazonas) in 1998, followed by Buenaventura (Valle del Cauca) in 2001, Barrancabermeja (Santander) in 2010, and Medellín (Antioquia) in 2011. So far, this species has been reported in ten departments of the country. Objective: To report the finding of A. albopictus in the city of Istmina, Chocó, and its implications for public health. Materials and methods: In January 2015, we conducted an inspection of immature stages of Aedes spp. in breeding sites in the neighborhoods of San Agustín, Santa Genoveva and Subestación in Istmina, Chocó. The immature stages collected in this municipality were identified at the Unidad de Entomología of the Laboratorio de Salud Pública Departamental de Chocó, and confirmed by the Laboratorio de Entomología, Red Nacional de Laboratorios, Instituto Nacional de Salud, in Bogotá. In January 2015, twelve A. albopictus larvae were found in the breeding sites located in Subestación and San Agustín neighborhoods. The occurrence of A. albopictus in the municipality of Istmina underlines the importance of strengthening continuous entomological surveillance strategies at national and local levels in the country, especially in Istmina and its surrounding municipalities.
Ngoagouni, Carine; Kamgang, Basile; Nakoun?, Emmanuel; Paupy, Chistophe; Kazanji, Mirdad
Aedes albopictus, a mosquito native to Asia, has invaded all five continents during the past three decades. It was reported in central Africa in the 2000s, first in Cameroon, and, since then, has colonised almost all countries of the region. The species, originally considered a secondary vector of dengue viruses, has been showed to play a major role in transmission of chikungunya virus in numerous countries, including in the central African region. We review the current spread of Ae. albopict...
Farjana, Thahsin; Tuno, Nobuko
The body size of mosquitoes can influence a number of bionomic factors, such as their blood-feeding ability, host attack rate, and fecundity. All of these traits are important determinants of their potential to transmit diseases. Among abiotic and biotic factors, high temperature and low nutrition in the developing stages of mosquitoes generally result in small adults. We studied the relationship between body size and multiple feeding in a gonotrophic cycle and some fecundity attributes by using three strains of two competent vector species, Aedes aegypti (L.) and Aedes albopictus (Skuse). We raised small and large mosquitoes under low and high food conditions in the laboratory to measure parameters of fecundity and blood-feeding behavior. Fecundity was positively correlated with body size in both species, whereas the number of bloodmeals, the frequency of host-seeking behavior, and egg retention were negatively correlated with body size in the Ae. albopictus Nagasaki strain. We found that multiple feeding and host-seeking behavior were negatively correlated with body size, i.e., small mosquitoes tended to have more contact with hosts. We found that two mechanisms that inhibit engorged mosquitoes from seeking out hosts, distension-induced and oocyte-induced inhibition, were not strong enough to limit host-seeking behavior, and multiple feeding increased fecundity. Size-dependent multiple feeding and host-seeking behavior affect contact frequency with hosts and should be considered when predicting how changes in mosquito body size affect disease transmission.
Bargielowski, I E; Lounibos, L P; Shin, D; Smartt, C T; Carrasquilla, M C; Henry, A; Navarro, J C; Paupy, C; Dennett, J A
Aedes aegypti and Aedes albopictus, two important vectors of the dengue and chikungunya viruses to humans, often come in contact in their invasive ranges. In these circumstances, a number of factors are thought to influence their population dynamics, including resource competition among the larval stages, prevailing environmental conditions and reproductive interference in the form of satyrization. As the distribution and abundance of Ae. aegypti and Ae. albopictus have profound epidemiological implications, understanding the competitive interactions that influence these patterns in nature is important. While evidence for resource competition and environmental factors had been gathered from the field, the evidence for reproductive interference, though strongly inferred through laboratory trials, remained sparse (one small-scale field trial). In this paper we demonstrate that low rates (1.12-3.73%) of interspecific mating occur in nature among populations of these species that have co-existed sympatrically from 3 to 150yrs. Finally this report contributes a new species-specific primer set for identifying the paternity of sperm extracted from field collected specimens. Copyright © 2015 Elsevier B.V. All rights reserved.
Monteiro, Laura C.C.; Souza, Jose R.B. de; Albuquerque, Cleide M.R. de
In tropical areas, where vector insects populations are particularly numerous, temperature usually range between 25 de C and 35 deg C. Considering the importance of such temperature variation in determining mosquitoes population dynamics, in this work the developmental, eclosion and survival rates of the immature stages of Aedes albopictus (Skuse) were compared under constant 25, 30 and 35 deg C (using acclimatized chambers) and environmental (25 deg C to 29 deg C) temperatures. The hatching rate was considered as total number of larvae recovered after 24h. The development period as well as larval and pupal survival rate were evaluated daily. Eclosion rate was significantly higher under environmental temperature than under the studied constant temperatures, suggesting that temperature variation may be an eclosion-stimulating factor. The mean eclosion time increased with the temperature, ranging from 2.8 h (25 deg C) to 5.2 h (35 deg C). The larval period was greatly variable inside each group, although it did not differ significantly amongst groups (11.0 +- 4.19 days), with individuals showing longer larval stages in water at 35 deg C (12.0 +- 4.95 days) and environmental temperature (13.6 +- 5.98 days). Oppositely, survival was strongly affected by the higher temperature, where only one individual lived through to adult phase. The results suggest that population of Ae. albopictus from Recife may be adapting to increasing of environmental temperatures and that the limiting temperature to larval development is around 35 deg C. (author)
Ruiling, Zhang; Tongkai, Liu; Zhendong, Huang; Guifen, Zhuang; Dezhen, Ma; Zhong, Zhang
Aedes albopictus has been described as one of the 100 worst invasive species in the world. This mosquito originated from southeastern Asia and currently has a widespread presence in every continent except Antarctica. The rapid global expansion of Ae. albopictus has increased public health concerns about arbovirus-related disease threats. Adaptation, adaption to novel areas is a biological challenge for invasive species, and the underlying processes can be studied at the molecular level. In this study, genetic analysis was performed using mitochondrial gene NADH dehydrogenase subunit 5 (ND5), based on both native and invasive populations. Altogether, 38 haplotypes were detected with H1 being the dominant and widely distributed in 21 countries. Both phylogenetic and network analyses supported the existence of five clades, with only clade I being involved in the subsequent global spread of Asian tiger mosquito. The other four clades (II, III, IV and V) were restricted to their original regions, which could be ancestral populations that had diverged from clade I in the early stages of evolution. Neutrality tests suggested that most of the populations had experienced recent expansion. Analysis of molecular variance and the population-pair statistic F ST revealed that most populations lacked genetic structure, while high variability was detected within populations. Multiple and independent human-mediated introductions may explain the present results. Copyright © 2018 Elsevier B.V. All rights reserved.
Little, E; Biehler, D; Leisnham, P T; Jordan, R; Wilson, S; LaDeau, S L
Social, ecological, and climatic factors interact creating a heterogeneous matrix that determines the spatiotemporal distribution of mosquitoes and human risks of exposure to the diseases they transmit. We explore linkages between the social and institutional processes behind residential abandonment, urban ecology, and the interactions of socio-ecological processes with abiotic drivers of mosquito production. Specifically, we test the relative roles of infrastructure degradation and vegetation for explaining the presence of Aedes albopictus Skuse 1894 to better predict spatial heterogeneity in mosquito exposure risk within urban environments. We further examine how precipitation interacts with these socially underpinned biophysical variables. We use a hierarchical statistical modeling approach to assess how environmental and climatic conditions over 3 years influence mosquito ecology across a socioeconomic gradient in Baltimore, MD. We show that decaying infrastructure and vegetation are important determinants of Ae. albopictus infestation. We demonstrate that both precipitation and vegetation influence mosquito production in ways that are mediated by the level of infrastructural decay on a given block. Mosquitoes were more common on blocks with greater abandonment, but when precipitation was low, mosquitoes were more likely to be found in higher-income neighborhoods with managed container habitat. Likewise, although increased vegetation was a negative predictor of mosquito infestation, more vegetation on blocks with high abandonment was associated with the largest mosquito populations. These findings indicate that fine spatial scale modeling of mosquito habitat within urban areas is needed to more accurately target vector control. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Recent research in mosquito population genetics suggests that interpopulation hybridization has likely contributed to the rapid spread of the container-breeding mosquitoes. Here, I used laboratory experiments to investigate whether interpopulation Aedes (Stegomyia) albopictus (Skuse) F1 and F2 hybrids exhibit higher fitness than parental populations, and whether hybrid mosquito performance is related to infection by the coevolved protozoan parasite Ascogregarina taiwanensis (Lien and Levine). Overall, there were significant differences in development time, wing length, and survival between the two parental mosquito populations, but no difference in per capita growth rate r. Hybrid mosquitoes were generally intermediate in phenotype to the parentals, except that F2 females were significantly larger than the midparent average. In addition, As. taiwanensis parasites produced fewest oocysts when they were reared in hosts of hybrid origin. These data suggest that hybridization between previously isolated mosquito populations can result in slight increases in potential mosquito reproductive success, via increased hybrid body size, and via the temporary escape from coevolved parasites. These findings are significant because studies have shown that even slight hybrid vigor can have positive fitness consequences for population persistence. Although this was a laboratory experiment extending only to the F2 generation, many other invasive insects also carry coevolved parasites, and thus the patterns seen in this mosquito system may be broadly relevant. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Full Text Available Background: Application of plant extracts as mosquito control strategy was practiced from centuries. These are easily available, non-toxic, biodegradable and exhibit broad-spectrum target specific activities against larval stages of mosquitoes.Method: Different potential parts of locally grown plants, seeds of nutmeg (Myristica fragrans, peel of musambi (Citrus sinensis, leaves of babuna (Matricaria chamomilla, mint (Mentha spicata and ginger rhizome (Zingiber officinale selected and evaluated for their larvicidal properties against Aedes (Stegomyis albopictus. Oils were extracted through steam distillation process and extracts were evaluated as per WHO 2005 guidelines for testing of insecticides against larvae of mosquitoes.Result: Among the five plant extracts, C. sinensis had the lowest LC50 (400.81ppm while M. fragrans had the highest LC50 value (710.30ppm respectively after 24h of exposure. In terms of % age mortality, a series of concentrations (300–800ppm gave high % mortality in case of C. sinensis while M. fragrans gave low % age mortality.Conclusion: All the five plant species have larvicidal effects to certain extant and C. sinensis had great potential. Further small-scale field trials with the extracts of the most promising one (C. sinensis shall be conducted to determine operational feasibility.
Koutsaviti, Katerina; Giatropoulos, Athanassios; Pitarokili, Danae; Papachristos, Dimitrios; Michaelakis, Antonios; Tzakou, Olga
The needle volatiles metabolites of seven Pinus spp.: Pinus nigra (3 samples), Pinus stankewiczii, Pinus brutia, Pinus halepensis, Pinus canariensis, Pinus pinaster and Pinus strobus from Greece were determined by gas chromatography and gas chromatography-mass spectrometry. P. nigra and P. canariensis essential oils were dominated by α-pinene (24.9-28.9 % and 15 %, respectively) and germacrene D (20.3-31.9 % and 55.8 %, respectively), whereas P. brutia and P. strobus by α-pinene (20.6 % and 31.4 %, respectively) and β-pinene (31.7 % and 33.6 %, respectively). P. halepensis and P. pinaster oils were characterized by β-caryophyllene (28.5 % and 22.5 %, respectively). Finally, β-pinene (31.4 %), germacrene D (23.3 %) and α-pinene (17.5 %) were the most abundant compounds in the needle oil of P. stankewiczii. Additionally the larvicidal and repellent properties of their essential oils were evaluated against Aedes albopictus, a mosquito of great ecological and medical importance. The results of bioassays revealed that repellent abilities of the tested essential oils were more potent than their larvicidal activities. The essential oils of P. brutia, P. halepensis and P. stankewiczii presented considerable larvicidal activity (LC50 values 67.04 mgL(-1) and 70.21 mgL(-1), respectively), while the others were weak to inactive against larvae. The essential oils of P. halepensis, P. brutia, and P. stankewiczii presented a high repellent activity, even at the dose of 0.2 μL cm(-2), while in the dose of 0.4 μL cm(-2), almost all the tested EOs displayed protection against the mosquito.
Hao, Huiling; Wei, Jianrong; Dai, Jianqing; Du, Jiawei
The changes of the host-seeking and blood-feeding behavior of Aedes albopictus (Skuse) (Diptera: Culicidae) surviving in a space containing vapors of the spatial repellents geraniol, eugenol, citral, anisaldehyde, or citronellal were evaluated using an arm-in-cage test and a bioassay of bloodmeals on a shaved mouse. The mosquitoes surviving concentrations of geraniol, citral, eugenol, or anisaldehyde at 0.013, 0.025, 0.050, 0.100, and 0.250 microg/cm3 for 24 and 48 h all showed different degrees of reduction in host-seeking ability. After 48 h of exposure to 0.250 microg/cm3 geraniol, almost 100% of the mosquitoes lost their host-seeking ability. The next most potent spatial repellent, anisaldehyde, stopped host seeking by > 85.5%. Citronellal did not result in a significant reduction in the host-seeking ability at any concentration level after either 24 or 48 h of treatment. We also found that reduction of host-seeking ability recovered after various times. The longest recovery time (144 h) was observed for geraniol after 24 h at 0.250 microg/cm3. In the study, geraniol, eugenol, and citral all significantly affected the activation and orientation stages of the blood-feeding behavior. However, only anisaldehyde significantly interrupted the normal blood-feeding of mosquitoes in all stages of behavior. These initial laboratory results clearly showed that anisaldehyde and geraniol could be promising spatial repellents against Ae. albopictus that they could play a major role in new repellent technology.
Oswaldo Paulo Forattini
Full Text Available OBJETIVO: Observar e comparar o comportamento das espécies de Aedes albopictus e de Ae. scapularis, na localidade de Pedrinhas, litoral sul do Estado de São Paulo, Brasil. MÉTODOS: As observações foram feitas de outubro de 1996 a janeiro de 2000. Foram realizadas coletas sistemáticas de formas adultas mediante a utilização de isca humana, aspirações ambientais e armadilha tipo Shannon. A domiciliação foi estimada pelo índice de Nuorteva e pela razão de sinantropia. RESULTADOS: Foram feitas 87 coletas diurnas, com a obtenção de 872 adultos fêmeas. As médias de Williams', multiplicadas por 100, foram de 118 e 21 para Ae. albopictus nos horários de 7h às 18h e de 18h às 20h, respectivamente. Quanto a Ae. scapularis, foram de 100 e 106 nos mesmos períodos. Esse último revelou pico de atividade crepuscular vespertina. Na aspiração de abrigos, obteve-se o total de 1.124 espécimens, dos quais 226 Ae. albopictus e 898 Ae. scapularis. O período de janeiro a maio correspondeu ao de maior rendimento para ambos os mosquitos. Quanto à armadilha de Shannon, as coletas realizadas na mata revelaram a ausência de Ae. albopictus. No que concerne à domiciliação, esse último mostrou os maiores valores de índices, enquanto Ae. scapularis revelou comportamento de tipo ubiquista. CONCLUSÕES: Os resultados confirmam outras observações, permitindo levantar hipóteses. Em relação a Ae. scapularis, sugere-se que possa existir fenômeno de diapausa das fêmeas no período verão-outono, a qual cessaria no inverno-primavera quando então a atividade seria retomada. Quanto a Ae. albopictus, os dados sugerem que se trata de população em processo adaptativo ao novo ambiente.OBJECTIVE: Aedes albopictus and Ae. scapularis were found living together in the Pedrinhas Village, Southeastern of São Paulo State, Brazil. This finding was a good opportunity to make observations about the mosquitoes' behavior. METHODS: From October 1996 to
David Pereira Neves
Full Text Available After the Aedees albopictus has been discoved by Neves & Espinola (1987 at Minas Gerais state, we begun studying some biologic aspects, such as breeding places, host preference, times of feeding and the preferred places for blood feeding.
Neves, David Pereira; Silva, Rivany Fernandes da
After the Aedees albopictus has been discoved by Neves & Espinola (1987) at Minas Gerais state, we begun studying some biologic aspects, such as breeding places, host preference, times of feeding and the preferred places for blood feeding.
Full Text Available Abstract Background Aedes (Stegomyia albopictus is currently one of the most notorious globally invasive mosquito species. Its medical importance is well documented, and its fast expansion throughout most continents is being monitored with concern. It is generally assumed that its expansion through the Western Pacific island countries has not progressed since its establishment in Fiji in 1989. However, the current status of Ae. albopictus in the Pacific region is largely unknown. Findings According to data from the literature and our own observations, Ae. albopictus is currently present in the following countries of the southern Pacific region: Papua New Guinea, Solomon Islands, Fiji, and the Kingdom of Tonga, where it was first detected in July 2011. It is absent from New Caledonia and French Polynesia where routine entomological surveillance is carried out, and was not detected during entomological work in 2007, either on the Cook Islands or on the Wallis and Futuna Islands. The species was not reported from American Samoa in 2004, but it is mentioned as probably present in Vanuatu. This is the first report of Ae. albopictus in Tonga. Conclusions The introduction and establishment of Ae. albopictus in Tonga was expected due to the geographical proximity of this country to Fiji where the species is strongly established. The pathway of introduction is unknown. The expansion of Ae. albopictus in the Pacific region poses an increasing threat to public health given the role this mosquito plays as primary vector of emerging infectious diseases such as Chikungunya fever.
Hahn, Micah B; Eisen, Lars; McAllister, Janet; Savage, Harry M; Mutebi, John-Paul; Eisen, Rebecca J
Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) are potential vectors of Zika, dengue, and chikungunya viruses in the United States. A Zika virus outbreak in Florida in the summer of 2016, driven by Ae. aegypti and resulting in > 200 locally acquired cases of human illness, underscored the need for up-to-date information on the geographic distribution of Ae. aegypti and Ae. albopictus in the United States. In early 2016, we conducted a survey and literature review to compile county records for presence of Ae. aegypti and Ae. albopictus in the United States from 1995 to 2016. Surveillance for these vectors was intensified across the United States during the summer and fall of 2016. At the end of 2016, we therefore conducted a follow-up survey of mosquito control agencies, university researchers, and state and local health departments to document new collection records for Ae. aegypti and Ae. albopictus. The repeated survey at the end of the year added Ae. aegypti collection records from 38 new counties and Ae. albopictus collection records from 127 new counties, representing a 21 and 10 percent increase, respectively, in the number of counties with reported presence of these mosquitoes compared with the previous report. Moreover, through our updated survey, 40 and 183 counties, respectively, added additional years of collection records for Ae. aegypti and Ae. albopictus from 1995 to 2016. Our findings underscore the continued need for systematic surveillance of Ae. aegypti and Ae. albopictus. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.
Valerio, Laura; Marini, Francesca; Bongiorno, Gioia; Facchinelli, Luca; Pombi, Marco; Caputo, Beniamino; Maroli, Michele; Della Torre, Alessandra
Knowledge of the frequency of contact between a mosquito species and its different hosts is essential to understand the role of each vector species in the transmission of diseases to humans and/or animals. However, no data are so far available on the feeding habits of Aedes albopictus in Italy or in other recently colonized temperate regions of Europe, due to difficulties in collecting blood-fed females of this diurnal and exophilic species. We analyzed Ae. albopictus host-feeding patterns in two urban and two rural sites within the area of Rome (Italy). Ae. albopictus was collected using sticky-traps and the blood-meal origin of 303 females was determined by direct dot-ELISA. The blood-fed sample, although representing only 4% of the total Ae. albopictus collected, demonstrates the useful application of sticky-trap in studying the feeding behavior of the species. The human blood index was significantly different among sites, ranging from 79-96% in urban sites to 23-55% in rural sites, where horses and bovines represented the most bitten hosts. The results obtained confirm the plastic feeding behavior shown by Ae. albopictus in its original range of distribution and highlights the high potential of this species as a vector of human pathogens in urban areas of Italy, where both humans and the mosquito itself may reach very high densities.
Full Text Available Abstract Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML method with the gene time reversible (GTR model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p -16 and period (F = 36.22, p = 2.548 × 10-13, that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough
María Elena Cuéllar-Jiménez
Conclusión. Es importante integrar el control de A. aegypti y A. albopictus en un solo programa. Se recomienda intensificar la vigilancia en los municipios y departamentos vecinos con el fin de limitar a tiempo el avance de la especie.
Full Text Available The Asian tiger mosquito Aedes albopictus is the most dominant species of subgenus Stegomyia and is medically important from the standpoint of transmitting wide range of human pathogens of deadly diseases like dengue, yellow fever and chikungunya. During present investigations, it has been observed that IX tergum in the male genitalia of Aedes albopictus varies greatly. It shows variations with respect to the presence or absence of lateral projections on the IX tergum, as well as in the shape and size of median and lateral projections. The shape of IX tergum in the male genitalia of Aedes species is of great taxonomic importance as it is a diagnostic character of the species. These variations have been observed both in natural populations collected from various breeding sites as well as in the adults reared in laboratory. The observed differences have not been noticed by any of the previous workers.
José Joaquín Carvajal
Full Text Available Introducción. Aedes albopictus se encuentra ampliamente distribuido en el mundo. Su introducción en las Américas ocurrió en 1985 y se le considera vector potencial de los virus del dengue y uno de los principales vectores del virus del chikungunya. En Colombia, su primer reporte fue en Leticia, Amazonas, en 1998, seguido de Buenaventura, Valle del Cauca, en 2001, Barrancabermeja, Santander, en 2010 y Medellín, Antioquia, en 2011. La especie se ha reportado en diez departamentos del país. Objetivo. Notificar el hallazgo de A. albopictus en el municipio de Istmina, Chocó, y dar cuenta de su importancia en salud pública. Materiales y métodos. En enero de 2015 se inspeccionaron criaderos de los barrios de San Agustín, Santa Genoveva y Subestación del municipio de Istmina para la detección de formas inmaduras de Aedes spp. Las larvas recolectadas fueron identificadas en la Unidad de Entomología del Laboratorio de Salud Pública Departamental de Chocó y confirmadas en el Laboratorio de Entomología de la Red Nacional de Laboratorios del Instituto Nacional de Salud en Bogotá. Resultados. Se encontraron doce larvas de A. albopictus en criaderos ubicados en los barrios Subestación y San Agustín en el municipio de Istmina. Conclusión. La detección de A. albopictus en el municipio de Istmina resalta la importancia del fortalecimiento de las estrategias de vigilancia entomológica continua a nivel municipal y departamental en el país, y especialmente en Istmina y los municipios aledaños.
Lauren F. Collins
Full Text Available The Asian tiger mosquito, Aedes albopictus, is a competent vector for arboviruses and recently was implicated as the vector of the first autochthonous cases of dengue and chikungunya in southern Europe. The objective of this study was to analyze the flight performance of female Ae. albopictus of different ages that were starved, sugar-fed, or sugar-fed and blood-fed, using flight mills. After three days of starvation post emergence, females flew an average distance of 0.7 ± 0.5 km in 1.9 ± 1.5 h during a 16 h trial period, whereas sugar- or sugar- and blood-fed females of this age covered a significantly higher distance of around 3 km with a mean total flight time of around 6 h. The age of females (up to four weeks had no effect on performance. The average of maximal continuous flight segments of sugar-fed (2.14 ± 0.69 h and blood-fed (3.17 ± 0.82 h females was distinctly higher than of starved females (0.38 ± 0.15 h of which most flyers (83% performed maximal flight segments that lasted no longer than 0.5 h. Overall, the results for the laboratory monitored flight performance of Ae. albopictus confirm their ability to disperse a few kilometres between breeding site and host.
Full Text Available Abstract Background Agrochemicals have been widely used in Pakistan for several years. This exposes mosquito populations, particularly those present around agricultural settings, to an intense selection pressure for insecticide resistance. The aim of the present study was to investigate the toxicity of representative agrochemicals against various populations of Aedes albopictus (Skuse collected from three different regions from 2008-2010. Results For organophosphates and pyrethroids, the resistance ratios compared with susceptible Lab-PK were in the range of 157-266 fold for chlorpyrifos, 24-52 fold for profenofos, 41-71 fold for triazofos, and 15-26 fold for cypermethrin, 15-53 fold for deltamethrin and 21-58 fold for lambdacyhalothrin. The resistance ratios for carbamates and new insecticides were in the range of 13-22 fold for methomyl, 24-30 fold for thiodicarb, and 41-101 fold for indoxacarb, 14-27 fold for emamectin benzoate and 23-50 fold for spinosad. Pair wise comparisons of the log LC50s of insecticides revealed correlation among several insecticides, suggesting a possible cross resistance mechanism. Moreover, resistance remained stable across 3 years, suggesting field selection for general fitness had also taken place for various populations of Ae. albopictus. Conclusion Moderate to high level of resistance to agrochemicals in Pakistani field populations of Ae. albopictus is reported here first time. The geographic extent of resistance is unknown but, if widespread, may lead to problems in future vector control.
Khan, Hafiz Azhar Ali; Akram, Waseem; Shehzad, Khurram; Shaalan, Essam A
Agrochemicals have been widely used in Pakistan for several years. This exposes mosquito populations, particularly those present around agricultural settings, to an intense selection pressure for insecticide resistance. The aim of the present study was to investigate the toxicity of representative agrochemicals against various populations of Aedes albopictus (Skuse) collected from three different regions from 2008-2010. For organophosphates and pyrethroids, the resistance ratios compared with susceptible Lab-PK were in the range of 157-266 fold for chlorpyrifos, 24-52 fold for profenofos, 41-71 fold for triazofos, and 15-26 fold for cypermethrin, 15-53 fold for deltamethrin and 21-58 fold for lambdacyhalothrin. The resistance ratios for carbamates and new insecticides were in the range of 13-22 fold for methomyl, 24-30 fold for thiodicarb, and 41-101 fold for indoxacarb, 14-27 fold for emamectin benzoate and 23-50 fold for spinosad. Pair wise comparisons of the log LC50s of insecticides revealed correlation among several insecticides, suggesting a possible cross resistance mechanism. Moreover, resistance remained stable across 3 years, suggesting field selection for general fitness had also taken place for various populations of Ae. albopictus. Moderate to high level of resistance to agrochemicals in Pakistani field populations of Ae. albopictus is reported here first time. The geographic extent of resistance is unknown but, if widespread, may lead to problems in future vector control.
Costanzo, K S; Schelble, S; Jerz, K; Keenan, M
Several studies have examined how climatic variables such as temperature and precipitation may affect life history traits in mosquitoes that are important to disease transmission. Despite its importance as a seasonal cue in nature, studies investigating the influence of photoperiod on such traits are relatively few. This study aims to investigate how photoperiod alters life history traits, survival, and blood-feeding activity in Aedes albopictus (Skuse) and Aedes aegypti (Linnaeus). We performed three experiments that tested the effects of day length on female survival, development time, adult size, fecundity, adult life span, and propensity to blood feed in Ae. albopictus and Ae. aegypti. Each experiment had three photoperiod treatments: 1) short-day (10L:14D), 2) control (12L:12D), and 3) long-day (14L:10D). Aedes albopictus adult females were consistently larger in size when reared in short-day conditions. Aedes aegypti adult females from short-day treatments lived longer and were more likely to take a blood meal compared to other treatments. We discuss how species-specific responses may reflect alternative strategies evolved to increase survival during unfavorable conditions. We review the potential impacts of these responses on seasonal transmission patterns, such as potentially increasing vectorial capacity of Ae. aegypti during periods of shorter day lengths. © 2015 The Society for Vector Ecology.
Lounibos, L Philip; Bargielowski, Irka; Carrasquilla, María Cristina; Nishimura, Naoya
The spread of Aedes albopictus (Skuse) eastward in the mid-1980s from its initial establishment in Houston, TX, was associated with rapid declines and local disappearances of Aedes aegypti (L.) in Gulf Coast states and Florida where annual larval surveillance during the early 1990s described temporal and spatial patterns of competitive displacements in cemeteries and tire shops. Approximately 20 yr later in 2013-2014, we re-visited former collection sites and sampled aquatic immatures of these two species from tire shops in 10 cities on State Route 441 and from 9 cemeteries from Lakeland to Miami in southwest Florida. In the recent samples Ae. aegypti was recovered from three central Florida cities where it had not been detected in 1994, but its northern limit on Rte. 441, Apopka, did not change. Other evidence, such as trends at a few cemeteries, suggested a moderate resurgence of this species since 1994. Cage experiments that exposed female progeny of Ae. aegypti from recent Florida collection sites to interspecific mating by Ae. albopictus males showed that females from coexistence sites had evolved resistance to cross-mating, but Ae. aegypti from sites with no Ae. albopictus were relatively susceptible to satyrization. Habitat classifications of collection sites were reduced by principal component (PC) analysis to four variables that accounted for > 99% of variances; PCs with strong positive loadings for tree cover and ground vegetation were associated with collection sites yielding only Ae. albopictus Within the coexistence range of the two species, the numbers of Ae. aegypti among total Aedes collected were strongly correlated in stepwise logistic regression models with two habitat-derived PCs, distance from the coast, and annual rainfall and mean maximum temperatures at the nearest weather station. Subtle increases in the range of Ae. aegypti since its previous displacements are interpreted in the context of the evolution of resistance to mating
Full Text Available The effects of temephos resistance on the fitness cost of the wild populations of Aedes albopictus was evaluated. The larvae of two wild populations were exposed to the diagnostic dose of 0.02 mg and 0.012 mg/L. The larvae which survived after the 24 h exposure to diagnostic dose were considered as resistant and F1 generations were chosen for the comparisons of fitness parameters with the control strain, which includes larval developmental time, adult longevity, fecundity, wing length and hatchability. We found that temephos resistance had negative effects on larval developmental time which was longer for Gelugor strain among the populations with the median range of 10 days and a shorter longevity was observed with the median range of 13 days for males and 16 days for females. Whereas, an effective reduction of 29.8 and 38.6% was observed in fertility and fecundity of Gelugor strain as compared to control strain. In contrast, no clear differences were found in biological parameters of Balik Palau and USM strain, except fecundity and fertility with a reduction of 13.4 and 15.5%, respectively. Whereas, no significant differences were seen in the wing size between the populations with the mean length (mm of 2.40 for Gelugor, 2.44 for Balik Palau and 2.46 for USM control (p > 0.05. Present results indicated that the temephos resistance is associated with the developmental and reproduction potential of resistant population of A. albopictus and the fitness has been compromised. Keywords: Temephos, Insecticides resistance, Fitness cost, Aedes albopictus, Dengue
Alarcón-Elbal, Pedro María; Estrella, Sarah Delacour; Arrondo, Ignacio Ruiz; Collantes, Francisco; Iniesta, Juan Antonio Delgado; Morales-Bueno, José; Sánchez-López, Pedro Francisco; Amela, Carmen; Sierra-Moros, María José; Molina, Ricardo; Lucientes, Javier
In 2004, Aedes (Stegomyia) albopictus (Skuse, 1894) was observed for the first time in Catalonia, northeastern Spain. A decade later, it has spread throughout the eastern Mediterranean region of the country and the Balearic Islands. Framed within a national surveillance project, we present the results of monitoring in 2013 in the autonomous communities of the mainland Levante. The current study reveals a remarkable increase in the spread of the invasive mosquito in relation to results from 2012; the species was present and well-established in 48 municipalities, most of which were along the Mediterranean coastline from the Valencian Community to the Region of Murcia. PMID:25317706
Valerio, L; Marini, F; Bongiorno, G; Facchinelli, L; Pombi, M; Caputo, B; Maroli, M; della Torre, A
We here report the results of field trials carried out in Rome with the aim to obtain data on the feeding behaviour of Aedes albopictus, in relation to different availability and abundance of putative hosts. Human Blood Index values were found higher than 75% in urban areas, where humans represented the most abundant hosts, and lower than 60% in rural areas, where host alternative to humans were frequent. The overall results confirm the generalist feeding-behaviour shown by this species in its original range of distribution and highlighting its high potential as vector of human pathogens in urban areas of Italy.
Full Text Available Stephanie L Richards, Avian V White, Jo Anne G Balanay Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC, USA Abstract: Chikungunya, dengue, and Zika viruses (CHIKV, family Togaviridae, genus Alphavirus; DENV and ZIKV, family Flaviviridae, genus Flavivirus are arboviruses that cause human epidemics. Due to the lack of vaccines for many mosquito-borne diseases, there is a need for mosquito control. In the US and other regions, residual barrier insecticide sprays are applied to foliage where female mosquitoes rest and/or sugar feed between blood meals. Residual sprays are an important control method for anthropogenic day-active sylvan mosquitoes such as Aedes albopictus (vector of CHIKV, DENV, and ZIKV that are difficult to control using ultralow-volume sprays applied only at dusk or dawn when these mosquitoes are not active. In this exploratory study, we analyzed the extent to which ingestion of a sublethal dose of the active ingredient bifenthrin affected vector competence (i.e., infection, dissemination, and transmission of Ae. albopictus for DENV and ZIKV. Two incubation periods (IPs; 7 and 14 d were tested at 28°C for insecticide-fed and sugar-fed mosquitoes. We show that mosquitoes that were fed bifenthrin (0.128 µg/mL mixed with sucrose solution exhibited significantly lower DENV infection rates and body titers after a 14-d IP. During the 7-d IP, one mosquito (sugar group transmitted ZIKV. During the 14-d IP, 100% of mosquitoes showed body and leg ZIKV infections, and one mosquito (sugar+bifenthrin group transmitted ZIKV. This is a preliminary communication, and more studies will be required to further investigate these findings. We expect the findings of this small-scale study to spur larger-scale investigations of the impacts of insecticides on mechanisms regulating vector competence, and exposure to other active ingredients, and aid in development of new
Giatropoulos, Athanassios; Pitarokili, Danae; Papaioannou, Fotini; Papachristos, Dimitrios P; Koliopoulos, George; Emmanouel, Nickolaos; Tzakou, Olga; Michaelakis, Antonios
The present study evaluated leaf essential oils from eight Cupresaceae species; Cupressus arizonica, Cupressus benthamii, Cupressus macrocarpa, Cupressus sempervirens, Cupressus torulosa, Chamaecyparis lawsoniana, Juniperus phoenicea, and Tetraclinis articulata for their larvicidal and repellent properties against Aedes albopictus, a mosquito of great ecological and medical importance. Based on the LC(50) values, C. benthamii essential oil was the most active (LC(50) = 37.5 mg/L) while the other tested Cupressaceae essential oils provided rather moderate toxicity against larvae (LC(50) = 47.9 to 70.6 mg/L). Under the used laboratory conditions, three of the essential oils (C. benthamii, C. lawsoniana, and C. macrocarpa) provided sufficient protection against mosquito adults, equivalent to the standard repellent "Deet" in the 0.2 mg/cm(2) dose, while C. macrocarpa assigned as the superior repellent oil in the 0.08 mg/cm(2) dose. Chemical analysis of the essential oils using gas chromatography and gas chromatography-mass spectrometry revealed the presence of 125 components.
Wasserberg, Gideon; White, L; Bullard, A; King, J; Maxwell, R
For organisms lacking parental care and where larval dispersal is limited, oviposition site selection decisions are critical fitness-enhancing choices. However, studies usually do not consider the interdependence of the two. In this study, we evaluated the effect of food level on the oviposition behavior of Aedes albopictus (Skuse) in the presence or the absence of a nonlethal predator (caged dragonfly nymph). We also attempted to quantify the perceived cost of predation to ovipositioning mosquitoes. Mosquitoes were presented with oviposition cups containing four levels of larval food (fermented leaf infusion) with or without a caged libellulid nymph. By titrating larval food, we estimated the amount of food needed to attract the female mosquito to oviposit in the riskier habitat. As expected, oviposition rate increased with food level and decreased in the presence of a predator. However, the effect of food level did not differ between predator treatments. By calculating the difference in the amount of food for points of equal oviposition rate in the predator-present and predator-absent regression lines, we estimated the cost of predation risk to be 1950 colony-forming-units per milliliter. Our study demonstrated the importance of considering the possible interdependence of predation risk and food abundance for oviposition-site-seeking insects. This study also quantified the perceived cost of predation and found it to be relatively low, a fact with positive implications for biological control.
Bibbs, Christopher S; Tsikolia, Maia; Bloomquist, Jeffrey R; Bernier, Ulrich R; Xue, Rui-De; Kaufman, Phillip E
Mosquito mortality has been documented in numerous studies of spatial repellents but the concentration-dependent toxicity of spatial repellent vapors has not been documented. To address this issue, prallethrin, flumethrin, metofluthrin, transfluthrin, and meperfluthrin were selected for comparative study against Aedes albopictus (Skuse), Ae. aegypti (L.), Culex quinquefasciatus Say, and Anopheles quadrimaculatus Say. Mosquito were exposed to vapors of each chemical for 2h, 4h, and 24h with mortality recorded at each time point. A second experiment involved exposing mosquitoes to vapors for 2h, then transferring them to untreated holding containers and held for 24h. For these mosquitoes, readings were only taken after 24h to allow for metabolic detoxification and recovery. The LC 50 and LC 90 data indicated that transfluthrin and meperfluthrin had the greatest toxicity across all species, followed by metofluthrin, prallethrin, and flumethrin. Our findings, through the direct comparison of these compounds, suggest that transfluthrin, meperfluthrin, and metofluthrin be considered for further development. The vapor toxicity for the aforementioned compounds significantly exceeds prallethrin, which is currently market available as an adulticidal active ingredient in public health pest control. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
van Dodewaard, Caitlin A M; Richards, Stephanie L; Harris, Jonathan W
Commercially available blood can be used as an alternative to live animals to maintain mosquito colonies and deliver infectious bloodmeals during research studies. We analyzed the extent to which two methods for blood coagulate removal (defibrination or addition of sodium citrate) affected life table characteristics (i.e., fecundity, fertility, hatch rate, and adult survival) and vector competence (infection, dissemination, and transmission) of Aedes albopictus (Skuse) for dengue virus (DENV). Two types of bovine blood were tested at two extrinsic incubation temperatures (27 or 30°C) for DENV-infected and uninfected mosquitoes. Fully engorged mosquitoes were transferred to individual cages containing an oviposition cup and a substrate. Eggs (fecundity) and hatched larvae (fertility) were counted. At 14 and 21 d post feeding on a DENV-infected bloodmeal, 15 mosquitoes were sampled from each group, and vector competence was analyzed (bodies [infection], legs [dissemination], and saliva [transmission]). Differences in life table characteristics and vector competence were analyzed for mosquitoes fed blood processed using different methods for removal of coagulates. The method for removal of coagulates significantly impacted fecundity, fertility, and hatch time in the uninfected group, but not DENV-infected group. Infected mosquitoes showed significantly higher fecundity and faster hatch time than uninfected mosquitoes. We show no significant differences in infection or dissemination rates between groups; however, horizontal transmission rate was significantly higher in mosquitoes fed DENV-infected citrated compared with defibrinated blood. We expect the findings of this study to inform research using artificial blood delivery methods to assess vector competence. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Full Text Available Abstract Background Oviposition-site choice is an essential component of the life history of all mosquito species. According to the oviposition-preference offspring-performance (P-P hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods We empirically tested the P-P hypothesis using the mosquito species Aedes albopictus by artificially manipulating two habitat conditions: diet (measured as mg of food added to a container and conspecific density (CD; number of pre-existing larvae of the same species. Immature development (larval mortality, development time to pupation and time to emergence and fitness (measured as wing length were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water and CD (0, 20, 40 and 80 larvae/300 ml water. Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of single-female oviposition site selection assay. Results Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (Two-Way CR ANOVA Post-Hoc test, P > 0.1. Development time decreased also as conspecific density increased from zero to 80 larvae (Two-Way CR ANOVA Post-Hoc test, P . Combined, these results support the role of density-dependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions This study supports predictions of the P-P hypothesis and provides a mechanistic understanding
Characterization of Aedes albopictus (Skuse, 1894 (Diptera:Culicidae larval habitats near the Amazon River in Colombia Caracterización preliminar de los sitios de cría de Aedes (Stegomyia albopictus (Skuse, 1894 (Diptera: Culicidae en el municipio de Leticia, Amazonas, Colombia
Víctor Alberto Olano
Full Text Available Introduction. Because the role of Aedes albopictus as an incriminated vector of several viral pathogens, its control is important to human health. To establish appropriate control methods, characterization of the larval habitats is a necessary first step.
Objective. Habitats of the immature stages of Ae. albopictus were characterized with respect to physical-chemical parameters and by floral and faunal arrays present.
Materials and methods. Leticia is located at the southernmost tip of Colombia on the banks of the Amazon River. In the urban area, 154 houses were inspected in December 2002 and January 2003. Physical-chemical data were collected, including exposure to sunlight, location, container size and material, water conductivity, and dissolved oxygen. Macroinvertebrates and plankton samples were taken at each positive larval site. The results were compared using descriptive analysis, principal component analysis, classification dendrograms, and diversity indexes.
Results. Twenty-one habitats were found positive for Diptera, and 13 were positive for Ae. albopictus larvae. Most of the positive habitats (92% were located near the houses--they were small or medium size receptacles located in the shade. This water generally had low conductivity and low turbidity, although high values of these parameters were also identified. The habitats had low diversity indexes for macroinvertebrates and high diversity indexes for plankton. In the principal component analysis, significant correlation was found with mites, oligochaetes and hemipterans (the macroinvertebrates and with bacilarophyceaes, clorophyceaes and cianophyceas (the algal forms.
Conclusion. In Leticia, females of Ae. albopictus were found in newly established habitats with sufficient availability of resources, low conductivity, and turbidity, lower intra-and interspecific competition.Introducción. Dada la importancia de Aedes albopictus en la salud pública, es necesario
Lima-Camara, Tamara Nunes; Lima, José Bento Pereira; Bruno, Rafaela Vieira; Peixoto, Alexandre Afranio
Dengue is an arbovirus disease transmitted by two Aedes mosquitoes: Ae. aegypti and Ae. albopictus. Virgin females of these two species generally show a bimodal and diurnal pattern of activity, with early morning and late afternoon peaks. Although some studies on the flight activity of virgin, inseminated and blood-fed Ae. aegypti females have been carried out under laboratory conditions, little is known about the effects of such physiological states on the locomotor activity of Ae. albopictus and Ae. aegypti females. The aim of this study was to analyze, under laboratory conditions, the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under LD 12:12, at 25°C. Both Ae. albopictus and Ae. aegypti females were obtained from established laboratory colonies. Control groups were represented by virgin/unfed Ae. albopictus and Ae. aegypti females. Experiments were conducted under laboratory conditions, using an activity monitor that registers individual activity every thirty minutes. Virgin/unfed Ae. albopictus and Ae. aegypti females showed a diurnal and bimodal pattern of locomotor activity, with peaks at early morning and late afternoon. Insemination and blood-feeding significantly decreased the locomotor activity of Ae. aegypti females, but inseminated/blood-fed Ae. aegypti and Ae. albopictus females showed a similar significant decrease on the locomotor activity compared to virgin/unfed females. This study is the first demonstration of the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under artificial conditions. Data suggest that Ae. albopictus and Ae. aegypti females respond in different ways to physiological status changes and such divergence between these two dengue vectors, associated with several ecological differences, could be related to the greater dengue vectorial capacity of Ae. aegypti in Americas in comparison to Ae. albopictus.
Xue, Rui-De; Qualls, Whitney A; Smith, Michael L; Gaines, Marcia K; Weaver, James H; Debboun, Mustapha
Repellent efficacy of the Off! Clip-on Mosquito Repellent device (S. C. Johnson and Son, Inc., Racine, WI) containing Metofluthrin was evaluated on six human volunteers against the container-breeding mosquito Aedes albopictus (Skuse) and the salt marsh mosquito Aedes taeniorhynchus (Wiedemann) at two field locations in northeastern Florida. The device repelled mosquitoes by releasing a vaporized form of the pyrethroid insecticide metofluthrin ([AI] 31.2%) and provided 70% protection from Ae. albopictus bites for > 3 h. For the second field trial, a repellent device that was used in the first trial was tested after being open for >1 wk. This device provided 79% protection from Ae. taeniorhynchus bites for 3 h. Our field results showed that the repellent device was 70 and 79% effective at repelling Ae. albopictus and Ae. taeniorhynchus from human test subjects in both field locations in northeastern Florida.
Sivan, Arun; Shriram, A N; Sunish, I P; Vidhya, P T
Mosquito foraging behavior is a determinant of host-vector contact and has an impact on the risk of arboviral epidemics. Therefore, blood-feeding patterns is a useful tool for assessing the role in pathogen transmission by vector mosquitoes. Competent vectors of dengue and chikungunya viz. Aedes aegypti and Aedes albopictus are widely prevalent in the Andaman and Nicobar archipelago. Considering the vector potential, medical importance of both these mosquito species and lack of information on host-feeding patterns, blood meal analysis of both these vector mosquitoes was undertaken. Biogents Sentinel traps were used for sampling blooded mosquitoes, for identifying the source of blood meal by agar gel-precipitin test. We identified vertebrate source of 147 and 104 blood meals in Ae. aegypti and Ae. albopictus from heterogeneous landscapes in South Andaman district. Results revealed that Ae. aegypti (88 %) and Ae. albopictus (49 %) fed on human and a small proportion on mammals and fowls, indicative of predominance of anthropophilism. Ae. aegypti predominantly fed on human blood (94.2 %-densely built urban, 89.8 %-low vegetation coverage, and 78.3 %-medium vegetation coverage). Anthropophilism in Ae. albopictus was maximal in densely built urban (90.5 %) and progressively decreased from low vegetation-vegetation/forested continuum (66.7, 36.4, and 8.7 %), indicating plasticity in feeding across these landscapes. Epidemiological significance of the findings is discussed.
Lima-Camara, Tamara N; Lima, José B P; Bruno, Rafaela V; Peixoto, Alexandre A
Abstract Background Dengue is an arbovirus disease transmitted by two Aedes mosquitoes: Ae. aegypti and Ae. albopictus. Virgin females of these two species generally show a bimodal and diurnal pattern of activity, with early morning and late afternoon peaks. Although some studies on the flight activity of virgin, inseminated and blood-fed Ae. aegypti females have been carried out under laboratory conditions, little...
Hashim, Nur Aida; Ahmad, Abu Hassan; Talib, Anita; Athaillah, Farida; Krishnan, Kumara Thevan
The occurrence of major outbreaks of dengue, and other vector borne diseases such as chikungunya and zika in tropical and subtropical regions has rendered control of the diseases a top-priority for many affected countries including Malaysia. Control of the mosquito vectors Aedes aegypti and Aedes albopictus through the reduction of breeding sites and the application of insecticides to kill immature forms and adults are the main control efforts to combat these diseases. The present study describes the association between Ae. albopictus and Ae. aegypti in shared breeding sites. This study is important given that any measure taken against one species may affect the other. A yearlong larval survey was conducted in four dengue endemic areas of Penang Island. Sorenson's coefficient index indicated that no association between number of the immatures of the two species regardless of container size and study location. Therefore, the mean number Ae. albopictus immature was not decreased in the presence of Ae. aegypti in shared breeding container. However Ae. aegypti appeared to prefer breeding in habitats not occupied by Ae. albopictus , the two species sharing breeding sites only where available containers were limited. In control efforts, eliminating the preferred breeding containers for one species might not affect or reduce the population of the other species.
Tantowijoyo, W; Arguni, E; Johnson, P; Budiwati, N; Nurhayati, P I; Fitriana, I; Wardana, S; Ardiansyah, H; Turley, A P; Ryan, P; O'Neill, S L; Hoffmann, A A
of mosquito vector populations, particularly through Wolbachia endosymbionts. The success of these strategies depends on understanding the dynamics of vector populations. In preparation for Wolbachia releases around Yogyakarta, we have studied Aedes populations in five hamlets. Adult monitoring with BioGent- Sentinel (BG-S) traps indicated that hamlet populations had different dynamics across the year; while there was an increase in Aedes aegypti (L.) and Aedes albopictus (Skuse) numbers in the wet season, species abundance remained relatively stable in some hamlets but changed markedly (>2 fold) in others. Local rainfall a month prior to monitoring partly predicted numbers of Ae. aegypti but not Ae. albopictus. Site differences in population size indicated by BG-S traps were also evident in ovitrap data. Egg or larval collections with ovitraps repeated at the same location suggested spatial autocorrelation (<250 m) in the areas of the hamlets where Ae. aegypti numbers were high. Overall, there was a weak negative association (r<0.43) between Ae. aegypti and Ae. albopictus numbers in ovitraps when averaged across collections. Ae. albopictus numbers in ovitraps and BG-S traps were positively correlated with vegetation around areas where traps were placed, while Ae. aegypti were negatively correlated with this feature. These data inform intervention strategies by defining periods when mosquito densities are high, highlighting the importance of local site characteristics on populations, and suggesting relatively weak interactions between Ae. aegypti and Ae. albopictus. They also indicate local areas within hamlets where consistently high mosquito densities may influence Wolbachia invasions and other interventions.
Muñnoz, Joaquin; Eritja, Roger; Alcaide, Miguel; Montalvo, Tomás; Soriguer, Ramón C; Figuerola, Jordi
The feeding patterns of haematophagous arthropods are of major importance in the amplification and transmission of infectious disease agents to vertebrate hosts, including humans. The establishment of new vector populations in nonnative range might alter transmission networks. The Asian tiger mosquito Aedes albopictus (Skuse) represents an example of how an invasive species can alter the risk of viral transmission to humans. Blood meal molecular identification from two sympatric mosquito species (the invasive Ae. albopictus and the native Culex pipiens) was carried out by polymerase chain reaction-based methods. Samples were collected in Barcelona metropolitan area, Spain, from June to October 2009 as part of a monitoring-control program. Blood meals were identified to the species level in 30 Ae. albopictus and 43 Cx. pipiens. Ae. albopictus acquired blood exclusively from human hosts (100%), whereas Cx. pipiens fed on a diversity of avian and mammalian hosts, including 35.7% of blood meals from humans. Based on mosquito diet, our results suggest that the Ae. albopictus invasion in Spain might increase the risk of virus transmission to humans and could support local outbreaks of imported tropical viruses such as dengue and chikungunya. However, in the studied area, the presence of this invasive species would have a negligible effect on the transmission of zoonotic agents such as West Nile virus. However, Cx. pipiens could amplify and transmit West Nile virus, but avian contribution to its diet was lower than that reported in North America. Feeding patterns of these mosquito species may help to understand the flavivirus outbreaks recently reported in southwestern Europe.
Schmidt, Chris A; Comeau, Genevieve; Monaghan, Andrew J; Williamson, Daniel J; Ernst, Kacey C
Transmission dynamics of mosquito-borne viruses such as dengue, Zika and chikungunya are affected by the longevity of the adult female mosquito. Environmental conditions influence the survival of adult female Aedes mosquitoes, the primary vectors of these viruses. While the association of temperature with Aedes mortality has been relatively well-explored, the role of humidity is less established. The current study's goals were to compile knowledge of the influence of humidity on adult survival in the important vector species Aedes aegypti and Ae. albopictus, and to quantify this relationship while accounting for the modifying effect of temperature. We performed a systematic literature review to identify studies reporting experimental results informing the relationships among temperature, humidity and adult survival in Ae. aegypti and Ae. albopictus. Using a novel simulation approach to harmonize disparate survival data, we conducted pooled survival analyses via stratified and mixed effects Cox regression to estimate temperature-dependent associations between humidity and mortality risk for these species across a broad range of temperatures and vapor pressure deficits. After screening 1517 articles, 17 studies (one in semi-field and 16 in laboratory settings) met inclusion criteria and collectively reported results for 192 survival experiments. We review and synthesize relevant findings from these studies. Our stratified model estimated a strong temperature-dependent association of humidity with mortality in both species, though associations were not significant for Ae. albopictus in the mixed effects model. Lowest mortality risks were estimated around 27.5 °C and 21.5 °C for Ae. aegypti and Ae. albopictus, respectively, and mortality increased non-linearly with decreasing humidity. Aedes aegypti had a survival advantage relative to Ae. albopictus in the stratified model under most conditions, but species differences were not significant in the mixed effects model
Full Text Available Dengue hemorrhagic fever (DHF is a viral disease that threatened community health in Indonesia. As part of an eradication program, it is important to learn the behavioral aspect of the disease vector. The aims of this study were to detect the presence of dengue virus in Aedes spp., at Bantarjati Village, Bogor City and to learn to bioecology of. Aedes aegypti (Linnaeus. Detection of dengue virus in Aedes spp. were done by reverse transcription-polymerase chain reaction (RT-PCR technique that consist of two phase were synthesis phase and cDNA amplification and dengue virus serotipe characterization. The Ae. aegypti and Ae. albopictus (Skuse mosquitoes were collected using the landing and resting moquito collection technique booth indoors and outdoors. The highest density of Ae. aegypti and Ae. albopictus were found in April and the peak activity was occurred at 10:00-11:00 am. Dengue virus was not detected in female mosquitoes Aedes spp.
Smartt, Chelsea T; Stenn, Tanise M S; Chen, Tse-Yu; Teixeira, Maria Gloria; Queiroz, Erivaldo P; Souza Dos Santos, Luciano; Queiroz, Gabriel A N; Ribeiro Souza, Kathleen; Kalabric Silva, Luciano; Shin, Dongyoung; Tabachnick, Walter J
A major mosquito-borne viral disease outbreak caused by Zika virus (ZIKV) occurred in Bahia, Brazil, in 2015, largely due to transmission by the mosquito, Aedes aegypti (L.). Detecting ZIKV in field samples of Ae. aegypti has proven problematic in some locations, suggesting other mosquito species might be contributing to the spread of ZIKV. In this study, several (five) adult Aedes albopictus (Skuse) mosquitoes that emerged from a 2015 field collection of eggs from Camaçari, Bahia, Brazil, were positive for ZIKV RNA; however, attempts to isolate live virus were not successful. Results from this study suggest that field-collected Ae. albopictus eggs may contain ZIKV RNA that require further tests for infectious ZIKV. There is a need to investigate the role of Ae. albopictus in the ZIKV infection process in Brazil and to study the potential presence of vertical and sexual transmission of ZIKV in this species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Nildimar Alves Honório
Full Text Available Experimental releases of female Aedes (Stegomyia aegypti and Aedes (Stegomyia albopictus were performed in August and September 1999, in an urban area of Nova Iguaçu, State of Rio de Janeiro, Brazil, to estimate their flight range in a circular area of 1,600 m where 1,472 ovitraps were set. Releases of 3,055 Ae. aegypti and 2,225 Ae. albopictus females, fed with rubidium (Rb-marked blood and surgically prevented from subsequent blood-feeding, were separated by 11 days. Rb was detected in ovitrap-collected eggs by atomic emission spectrophotometry. Rb-marked eggs of both species were detected up to 800 m from the release point. Eggs of Ae. albopictus were more numerous and more heterogeneously distributed in the area than those of Ae. aegypti. Eggs positively marked for Rb were found at all borders of the study area, suggesting that egg laying also occurred beyond these limits. Results from this study suggest that females can fly at least 800 m in 6 days and, if infected, potentially spread virus rapidly.
Xue, Rui-De; Ali, Arshad; Barnard, Donald R
Aedes albopictus mosquito is an opportunistic blood feeder and has a broad host range. The feeding behavior and habits of this mosquito are liable to increase the transmission potential of arboviruses. The survival and fecundity in A. albopictus fed on different hosts and post-blood meal provision of sugar were investigated in a laboratory-reared colony. Adult survival of caged female A. albopictus that were fed on blood of two different hosts (double meal) was higher than the females fed only on one host (single meal) (mean survival: 70.2+/-9.6 vs. 55.5+/-5.5%, respectively) when held in the laboratory for 72 h after blood feeding. Mean survival of females provided 10% sucrose solution (in water) after a single or double blood meal was higher (90.5+/-6.4% and 89.3+/-6.5%, respectively) than in the respective groups receiving water only following blood feeding (double meal: 49.0+/-9.6%; single meal: 45.3+/-10.9%). Females receiving a double meal were more fecund on average (89.0+/-6.6 eggs) than females provided a single meal (82.3+/-8.2 eggs).
Sivan, Arun; Shriram, Ananganallur Nagarajan; Muruganandam, Nagarajan; Thamizhmani, Ramanathan
Climatic changes are responsible, to a certain extent for the occurrence and spread of arboviral pathogens world over. Temperature is one of the important abiotic factors influencing the physiological processes of mosquitoes. Several genes of heat shock protein (HSP) families are known to be expressed in mosquitoes, which aid in overcoming stress induced by elevated temperature. In order to understand expression of HSP family genes in the Andaman population of Aedes aegypti and Aedes albopictus, we used quantitative real-time polymerase chain reaction (qPCR) to examine expression levels of HSPs in response to thermal stress under laboratory and in actual field conditions. HSP genes AeaHsp26, AeaHsp83 and AeaHsc70 were examined by comparing relative transcript expression levels at 31°C, 33°C, 34°C, 37°C and 39°C respectively. Enhanced up-regulation of HSPs was evident in third instar larvae of Ae. aegypti with rise in water temperatures (31°C, 33°C, 34°C) in the containers in the nature and thermally stressed (37°C and 39°C) in laboratory conditions. In Ae. albopictus up-regulation of HSPs was observed in field conditions at 34°C only and when thermally treated at 37°C, while down regulation was evident in larvae subjected to thermal stress in laboratory at 39°C. Data on expression levels revealed that larvae of Ae. aegypti was tolerant to thermal stress, while Ae. albopictus larvae was sensitive to heat shock treatment. Statistical analysis indicated that AeaHsp83 genes were significantly up-regulated in Ae. aegypti larvae after 360min exposure to high temperature (39°C). The difference in expression levels of AeaHsp26, AeaHsc70 and AeaHsp83 genes in Ae. albopictus larvae was statistically significant between different exposure temperatures. All of these genes were significantly up-regulated at 37°C. These results indicate that AeaHsp26, AeaHsc70 and AeaHsp83 are important markers of stress and perhaps function as proteins conferring protection and
Westby, Katie M; Muturi, Ephantus J; Juliano, Steven A
Evolutionary theory predicts that vector-borne pathogens should have low virulence for their vector because of selection against pathogens that harm the vector sufficiently to reduce transmission. Environmental factors such as nutritional stress can alter vector-pathogen associations by making the vectors more susceptible to pathogens (condition-dependent competence) and vulnerable to the harm caused by pathogen replication (condition-dependent virulence). We tested the hypotheses of condition-dependent competence and condition-dependent virulence by examining the interactive effects of short-term sugar deprivation and exposure to La Crosse virus (LACV) in female Aedes albopictus (Skuse). We predicted that infection status interacts with sugar deprivation to alter willingness to blood feed and fecundity in the second gonotrophic cycle (condition-dependent virulence). Sugar deprivation had no effect on body infection or disseminated infection rates. Infection status, sugar treatment, and their interaction had no effect on fecundity. Mosquitoes that had intermittent access to sugar were significantly more willing to take a second bloodmeal compared with those that had continuous access to sugar. Infection status and the interaction with sugar treatment had no effect on blood-feeding behavior. Thus, we found no evidence of short-term sugar deprivation leading to condition-dependent competence for, or condition-dependent virulence of, LACV in Ae. albopictus. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Dunford, James C; Falconer, Aneika; Leite, Laura N; Wirtz, Robert A; Brogdon, William G
Emerging and re-emerging vector-borne diseases such as chikungunya and dengue and associated Aedes vectors are expanding their historical ranges; thus, there is a need for the development of novel insecticides for use in vector control programs. The mosquito toxicity of a novel insecticide and repellent consisting of medium-chain carbon fatty acids (C8910) was examined. Determination of LC 50 and LC 90 was made against colony-reared Aedes aegypti (L.) and Aedes albopictus (Skuse) using probit analysis on mortality data generated by Centers for Disease Control and Prevention bottle bioassays. Six different concentrations of C8910 + silicone oil yielded an LC 50 of 160.3 µg a.i/bottle (147.6-182.7) and LC 90 of 282.8 (233.2-394.2) in Ae. aegypti; five concentrations yielded an LC 50 of 125.4 (116.1-137.6) and LC 90 of 192.5 (165.0-278.9) in Ae. albopictus. Further development of C8910 and similar compounds could provide vector control specialists novel insecticides for controlling insect disease vectors. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.
Preferência por local de oviposição de Aedes albopictus (Skuse (Diptera, Culicidae, em relação à presença de imaturos da própria espécie, sob condições de laboratório Aedes (Stegomyia albopictus (Skuse (Diptera, Culicidae, preference for oviposition site related with homospecific immatures presence, under laboratory conditions
Andreia Aparecida Barbosa
Full Text Available Aedes (Stegomyia albopictus (Skuse, 1894 is an exotic Culicidae species in Brazil. Since its first report in this country, the mosquito has been increasing its geographic distribution. This mosquito is a natural dengue and Japanese Encephalitis virus vector in Asia. The females preference for oviposition sites related with homospecific immature presence was assessed. The experiment was performed with Aedes albopictus from laboratory colony since March ]999, in the Laboratório de Entomologia Médica e Veterinária, Departamento de Zoologia, Universidade Federal do Paraná. The preferred container was the one that kept pupae for 24 hours, with 643 eggs, 30,6% at total. The eggs recipients received 11,45% from total set by the females, and the following numbers to the others: larva 1 (15,79%, larva 2 (14,69%, pupa 1 (20,74%, pupa 2 (30,58%, control (6,75%. Although the ANOVA did not detect significant difference among the treatments, the data possibly indicate that Aedes albopictus prefer laying eggs in containers previously colonized by immature.
Genetic Characterization of Spondweni and Zika Viruses and Susceptibility of Geographically Distinct Strains of Aedes aegypti, Aedes albopictus and Culex quinquefasciatus (Diptera: Culicidae to Spondweni Virus.
Andrew D Haddow
Full Text Available Zika virus (ZIKV has extended its known geographic distribution to the New World and is now responsible for severe clinical complications in a subset of patients. While substantial genetic and vector susceptibility data exist for ZIKV, less is known for the closest related flavivirus, Spondweni virus (SPONV. Both ZIKV and SPONV have been known to circulate in Africa since the mid-1900s, but neither has been genetically characterized by gene and compared in parallel. Furthermore, the susceptibility of peridomestic mosquito species incriminated or suspected in the transmission of ZIKV to SPONV was unknown.In this study, two geographically distinct strains of SPONV were genetically characterized and compared to nine genetically and geographically distinct ZIKV strains. Additionally, the susceptibility of both SPONV strains was determined in three mosquito species. The open reading frame (ORF of the SPONV 1952 Nigerian Chuku strain, exhibited a nucleotide and amino acid identity of 97.8% and 99.2%, respectively, when compared to the SPONV 1954 prototype South African SA Ar 94 strain. The ORF of the SPONV Chuku strain exhibited a nucleotide and amino acid identity that ranged from 68.3% to 69.0% and 74.6% to 75.0%, respectively, when compared to nine geographically and genetically distinct strains of ZIKV. The ORF of the nine African and Asian lineage ZIKV strains exhibited limited nucleotide divergence. Aedes aegypti, Ae. albopictus and Culex quinquefasciatus susceptibility and dissemination was low or non-existent following artificial infectious blood feeding of moderate doses of both SPONV strains.SPONV and ZIKV nucleotide and amino acid divergence coupled with differences in geographic distribution, ecology and vector species support previous reports that these viruses are separate species. Furthermore, the low degree of SPONV infection or dissemination in Ae. albopictus, Ae. aegypti and Cx. quinquefasciatus following exposure to two
Haddow, Andrew D., E-mail: firstname.lastname@example.org [Institute for Human Infections and Immunity, Center for Emerging Infectious Diseases and Biodefense, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States); Guzman, Hilda; Popov, Vsevolod L. [Institute for Human Infections and Immunity, Center for Emerging Infectious Diseases and Biodefense, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States); Wood, Thomas G.; Widen, Steven G. [Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States); Haddow, Alastair D. [Mercy Clinic, 2115 S. Fremont, Springfield, MO 65804 (United States); Tesh, Robert B.; Weaver, Scott C. [Institute for Human Infections and Immunity, Center for Emerging Infectious Diseases and Biodefense, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States)
We report here the first evidence of vertical transmission of Aedes flavivirus (AEFV) and its first isolation in the Western Hemisphere. AEFV strain SPFLD-MO-2011-MP6 was isolated in C6/36 cells from a pool of male Aedes albopictus mosquitoes that were reared to adults from larvae collected in southwest Missouri, USA, in 2011. Electron micrographs of the virus showed virions of approximately 45 nm in diameter with morphological characteristics associated with flaviviruses. The genomic sequence demonstrated that AEFV-SPFLD-MO-2011-MP6 shares a high degree of nucleotide and amino acid sequence identity with the AEFV Narita-21 strain, isolated in Japan in 2003. Intracerebral inoculation of newborn mice with the virus failed to produce observable illness or death and the virus did not replicate in vertebrate cells, consistent with a lack of vertebrate host range. - Highlights: ► The first report of Aedes flavivirus (AEFV) in the Western Hemisphere. ► The first evidence of vertical transmission of AEFV in mosquitoes. ► The first electron micrograph of AEFV. ► The first attempt to infect animals with AEFV.
Kothera, Linda; Byrd, Brian; Savage, Harry M
Aedes aegypti (L.) and Ae. albopictus (Skuse) are important arbovirus vectors in the United States, and the recent emergence of Zika virus disease as a public health concern in the Americas has reinforced a need for tools to rapidly distinguish between these species in collections made by vector control agencies. We developed a duplex real-time PCR assay that detects both species and does not cross-amplify in any of the other seven Aedes species tested. The lower limit of detection for our assay is equivalent to ∼0.03 of a first-instar larva in a 60-µl sample (0.016 ng of DNA per real-time PCR reaction). The assay was sensitive and specific in mixtures of both species that reflected up to a 2,000-fold difference in DNA concentration. In addition, we developed a simple protocol to extract DNA from sonicated first-instar larvae, and used that DNA to test the assay. Because it uses real-time PCR, the assay saves time by not requiring a separate visualization step. This assay can reduce the time needed for vector control agencies to make species identifications, and thus inform decisions about surveillance and control. Published by Oxford University Press on behalf of Entomological Society of America 2017 This work is written by US Government employees and is in the public domain in the US.
Haddow, Andrew D.; Guzman, Hilda; Popov, Vsevolod L.; Wood, Thomas G.; Widen, Steven G.; Haddow, Alastair D.; Tesh, Robert B.; Weaver, Scott C.
We report here the first evidence of vertical transmission of Aedes flavivirus (AEFV) and its first isolation in the Western Hemisphere. AEFV strain SPFLD-MO-2011-MP6 was isolated in C6/36 cells from a pool of male Aedes albopictus mosquitoes that were reared to adults from larvae collected in southwest Missouri, USA, in 2011. Electron micrographs of the virus showed virions of approximately 45 nm in diameter with morphological characteristics associated with flaviviruses. The genomic sequence demonstrated that AEFV-SPFLD-MO-2011-MP6 shares a high degree of nucleotide and amino acid sequence identity with the AEFV Narita-21 strain, isolated in Japan in 2003. Intracerebral inoculation of newborn mice with the virus failed to produce observable illness or death and the virus did not replicate in vertebrate cells, consistent with a lack of vertebrate host range. - Highlights: ► The first report of Aedes flavivirus (AEFV) in the Western Hemisphere. ► The first evidence of vertical transmission of AEFV in mosquitoes. ► The first electron micrograph of AEFV. ► The first attempt to infect animals with AEFV
Comportamento antropofílico de Aedes albopictus (Skuse (Diptera: Culicidae na região do Vale do Paraíba, Sudeste do Brasil Anthropophilic behaviour of Aedes albopictus (Skuse (Diptera: Culicidae in the Vale do Paraíba region, Southeastern Brazil
Gisela Rita Alvarenga Monteiro Marques
Full Text Available INTRODUÇÃO: A avaliação do papel epidemiológico de Aedes albopictus no Estado de São Paulo está sendo investigado com base em suas características biológica e ecológica. Nessa linha objetivou-se determinar a atividade hematófaga dessa espécie, tendo como parâmetros a posição estacionária e em movimento do homem utilizado como isca. MATERIAL E MÉTODO: A pesquisa foi desenvolvida numa chácara localizada na zona periurbana da cidade de Tremembé, Vale do Paraíba, Estado de São Paulo, Brasil. Aedes albopictus foi capturado sob duas modalidades técnicas de isca humana: uma correspondeu a período de 24 horas ininterruptas, com os coletores em ponto único, e outra, de duas horas, com os coletores visitando, por 5 min, 48 pontos, distando 10 m entre si, nos períodos da manhã e tarde. Ambas foram executadas mensalmente durante 12 meses (1989/90. RESULTADOS: As 24 capturas realizadas renderam 637 fêmeas de Ae.albopictus, sendo 54 (8,4% e 583 (91,6%, respectivamente, para posição estacionário e móvel, do coletor. Fez-se análise sobre a influência da mobilidade do hospedeiro como estímulo atrativo para esta espécie. A atividade horária detectada foi diurna, com picos às 6:00h, entre 13 e 14h, e o maior das 16 às 17 horas. A abundância de adulto correspondeu às estações verão/outono, mas na modalidade de coleta móvel a presença das fêmeas foi prolongada por todo o ano. A chuva e temperatura foram fatores de análise pelas suas correlações com a abundância e redução dos adultos de Ae.albopictus. CONCLUSÃO: Demonstrou-se ser complexa a influência de fatores endógenos e exógenos na prática da hematofagia de Aedes albopictus. Contudo pareceu claro que o comportamento desta prática, nas modalidades estudadas, demonstrou vôo direcional ao hospedeiro num raio supostamente pequeno, e vôo apetente, menos significativo, demonstrado pela posição estacionária do coletor. Atividade de hematofagia foi
Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...
Tuno, N; Kohzu, A; Tayasu, I; Nakayama, T; Githeko, A; Yan, G
The population sizes of Anopheles gambiae Giles (Diptera: Culicidae) and Anopheles arabiensis Patton (Diptera: Culicidae) increase dramatically with the onset of the rainy season in sub-Saharan Africa, but the ecological mechanisms underlying the increases are not well understood. As a first step toward to understand, we investigated the proliferation of algae, the major food of mosquito larvae, in artificial fresh water bodies exposed to sunlight for a short period, and old water bodies exposed to sunlight for a long period, and the effects thereof on the development of these anopheline larvae. We found that an epizoic green algal species of the genus Rhopalosolen (Chlorophyta: Chlorophyceae) proliferated immediately after water freshly taken from a spring was placed in sunlight. This alga proliferated only briefly (for ~10 d) even if the water was repeatedly exposed to sunlight. However, various algal species were observed in water that remained under sunlight for 40 d or longer (i.e., in old water bodies). The growth performance of larvae was higher in sunlight-exposed (alga-rich) water than in shade-stored (alga-poor) water. Stable isotope analysis suggested that these two anopheline species fed on Rhopalosolen algae in fresh water bodies but hardly at all on other algae occurring in the old water bodies. We concluded that freshly formed ground water pools facilitate high production of anopheline species because of the proliferation of Rhopalosolen algae therein, and the increase in the number of such pools in the rainy season, followed by rapid increases in A. gambiae and A. arabiensis numbers. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: email@example.com.
Diptera: Culicidae). Rev. Bras. Entomol. 10: 169-187. 1962. Entomologia medica, vol. I. Parte Geral, Diptera, Anophelini. Faculdade de Higiene e...Ronderos. 1962. Mosquitos de la Re- Ortiz, I. 1968. Apuentes de entomologia medica: 10s mos- publica Argentina. I. Tribu Anophelini (Diptera - Culic
Guo, Xiao-Xia; Li, Chun-Xiao; Zhang, Ying-Mei; Xing, Dan; Dong, Yan-De; Zhang, Heng-Duan; Qin, Cheng-Feng; Zhao, Tong-Yan
Dengue is an acute, emerging, infectious disease transmitted by Aedes mosquitoes that has become a serious global public health problem. The DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus were originally isolated from the serum of a patient with dengue fever in Fujian Province, China, in 1999. Our data provide the first assessment of the vector competence of Aedes mosquitoes with respect to the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus. There were significant differences in the replication rates of these two viral strains in Aedes albopictus and Aedes aegypti (P0.05). In summary, our results indicate that Ae. albopictus and Ae. aegypti mosquitoes are moderately competent vectors of the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus and provide the first evidence of the effect of these two viral strains on the vector competence of mosquitoes in China. Copyright © 2016 Elsevier B.V. All rights reserved.
Lau, Koon Weng; Chen, Chee Dhang; Lee, Han Lim; Low, Van Lun; Sofian-Azirun, Mohd
The susceptibility status of Aedes albopictus (Skuse; Diptera: Culicidea) larvae collected from 13 districts in Sarawak state, Malaysia was evaluated against five insect growth regulators (IGRs) namely, methoprene, pyriproxyfen, diflubenzuron, cyromazine, and novaluron. Field populations of Ae. albopictus were susceptible to methoprene, pyriproxyfen, cyromazine and novaluron with resistance ratios (RRs) ranging from 0.19-0.38, 0.05-0.14, 0.50-0.95, and 0.75-1.00, respectively. Nevertheless, tolerance towards diflubenzuron (0.33-1.33) was observed in this study. In general, these IGRs exhibited promising results and can be used as alternative control agents against field populations of Ae. albopictus in Sarawak, Malaysia.
Fonseca, Dina M.
Aedes japonicus japonicus (Theobald) (Diptera: Culicidae) has recently expanded beyond its native range of Japan and Korea into large parts of North America and Central Europe. Population genetic studies begun immediately after the species was detected in North America revealed genetically distinct introductions that subsequently merged, likely contributing to the successful expansion. Interactions, particularly in the larval stage, with other known disease vectors give this invasive subspecies the potential to influence local disease dynamics. Its successful invasion likely does not involve superior direct competitive abilities, but it is associated with the use of diverse larval habitats and a cold tolerance that allows an expanded seasonal activity range in temperate climates. We predict a continued but slower expansion of Ae. j. japonicus in North America and a continued rapid expansion into other areas as this mosquito will eventually be considered a permanent resident of much of North America, Europe, Asia, and parts of Hawaii. PMID:24397520
Full Text Available Foram feitas coletas de mosquito (Diptera: Culicidae na área do projeto de Colonização Pedro Peixoto, no Estado do Acre, Brasil. Obteve-se um total de 4.588 exemplares pertencentes a 53 espécies ou grupos. Salienta-se a ocorrência de Anopheles (Nyssorhynchus oswaldoi.Mosquito (Diptera: Culicidae collections were made on the Pedro Peixoto Colonization Project in the State of Acre, Brazil. Four thousand, five hundred and eighty-eight (4,588 specimens were collected and fifty-three (53 species or group recognised. The occurrence of Anopheles (Nyssorhynchus oswaldoi is given special emphasis.
Neiva & Pinto) (Diptera: Culicidae) Maria Anice Mureb Sallum/+, Richard C Wilkerson* Núcleo de Pesquisa Taxonômica e Sistemática em Entomologia ...Taxonômica e Sistemática em Entomologia Médica, Universidade de São Paulo, São Paulo. The following specimens were used for setal counts and measurements (the
Full Text Available The present paper reports the preliminary results of the survey of the mosquito fauna (Diptera: Culicidae in Maliuc - Mila 26 area, in 2006. A number of 1,255 mosquitoes, belonging to 14 species have beencaptured in three investigation sites. The results of the data-analysis were used for drawing up the annual dynamics of the various mosquito species from a specific location in Maliuc - Mila 26 area for the period April –September.
Rosa Sá Gomes Hutchings
Full Text Available With 312 trap-hours of sampling effort, 1554 specimens of Culicidae (Diptera were collected, using CDC and Malaise traps, in nine different locations along the Juami River, within the Juami-Japurá Ecological Station, Amazonas State, Brazil. A list of mosquito species with 54 taxa is presented, which includes three new distributional records for the state of Amazonas. The species found belong to the genera Anopheles, Aedeomyia, Aedes, Psorophora, Culex, Coquillettidia, Sabethes, Wyeomyia and Uranotaenia.
Toxicity of Thiophenes from Echinops transiliensis (Asteraceae) against Aedes aegypti (Diptera: Culicidae) Larvae by Hiroshi Nakano*a)b)c), Abbas...larvicides against Aedes aegypti. Structural differences among compounds 3, 5, and 8 consisted in differing AcO and OH groups attached to C(3’’) and C(4...serious human diseases including malaria, Japanese encephalitis, yellow fever, dengue, and filariasis. The urban-adapted Aedes aegypti mosquito has become
Mosquitos no litoral paranaense. I - Idade fisioldgica de no Parque National da Serra dos Orgaos, Anopheles cruzii (Diptera, Culicidae). Arq. Estado do...no Parque National da Peryassii, A.G. 1908. OS culicideos do Brazil. Serra dos Grgaos, Estado do Rio de Janeiro, Inst. de Manguinhos, Rio de Janeiro...Kerteszia no litoral Guimar%es, A.E. and V.N.M. Victoria. 1986. do estado de Santa Catarina. Rev. Bras. Mosquitos no Parque National da Serra dos
van den Hurk, Andrew F; Johnson, Petrina H; Hall-Mendelin, Sonja; Northill, Judy A; Simmons, Russell J; Jansen, Cassie C; Frances, Stephen P; Smith, Greg A; Ritchie, Scott A
Biological transmission of arboviruses to a vertebrate host occurs when virions are expelled along with saliva during blood feeding by a hematophagous arthropod. We undertook experiments to determine whether mosquitoes expectorate flaviviruses in their saliva while sugar feeding. Batches of Culex annulirostris Skuse and Culex gelidus Theobald (Diptera: Culicidae) were orally infected with Japanese encephalitis (family Flaviviridae, genus Flavivirus, JEV), Kunjin (family Flaviviridae, genus Flavivirus, KUNV; a subtype of West Nile virus), and Murray Valley encephalitis (family Flaviviridae, genus Flavivirus, MVEV) viruses. After a 7-d extrinsic incubation, these mosquitoes were offered sucrose meals via cotton pledgets, which were removed daily and processed for viral RNA by using real-time TaqMan reverse transcriptase-polymerase chain reaction (RT-PCR) assays. JEV, MVEV, and KUNV RNA was detected in all pledgets removed from batches of Cx. gelidus on days 7-14 postexposure. In contrast, detection rates were variable for Cx. annulirostris, with KUNV detected in 0.3 M sucrose pledgets on all days postexposure, and JEV and MVEV detected on 57 and 50% of days postexposure, respectively. Higher concentrations of sucrose in the pledget did not increase virus detection rates. When individual JEV-infected Cx. gelidus were exposed to the sucrose pledget, 73% of mosquitoes expectorated virus with titers that were detectable by TaqMan RT-PCR. These results clearly show that flaviviruses are expectorated by infected mosquitoes during the process of sugar feeding on artificial pledgets. Potential applications of the method for arboviral bioassays and field surveillance are discussed.
The Subgenus Stegomyia of Aedes in the Afrotropical Region. 2. The Dendrophilus Group of Species (Diptera: Culicidae) (Contributions of the American Entomological Institute. Volume 29, Number 4, 1997)
or reservoirs of eight viruses , six of which cause human illness (Chikungunya, dengue 1 and 2, Dugbe, Rift Valley fever, yellow fever and Zika ...suggested that Ae. deboeri may be the jungle vector of the yellow fever virus in Langata. A edes Aedes Aedes Aedes (Stegomyia) demeilloni Edwards... Aedes (Stegomyia) Iedgeri (Diptera: Culicidae). Mosq. Syst. 13: 92-113. Aedes (Stegomyia) bromeliae (Diptera: Culicidae), the yellow fever virus
Full Text Available Foram feitas coletas de mosquito (Diptera: Culicidae na área do projeto de Colonização Pedro Peixoto, no Estado do Acre, Brasil. Obteve-se um total de 4.588 exemplares pertencentes a 53 espécies ou grupos. Salienta-se a ocorrência de Anopheles (Nyssorhynchus oswaldoi.
Qiu, Y.T.; Smallegange, R.C.; Braak, ter C.J.F.; Spitzen, J.; Loon, van J.J.A.; Jawara, M.; Milligan, P.; Galimard, A.M.S.; Beek, van T.A.; Knols, B.G.J.; Takken, W.
Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to
Full Text Available Foram feitas coletas de mosquito (Diptera: Culicidae na área do projeto de Colonização Pedro Peixoto, no Estado do Acre, Brasil. Obteve-se um total de 4.588 exemplares pertencentes a 53 espécies ou grupos. Salienta-se a ocorrência de Anopheles (Nyssorhynchus oswaldoi.
104. Brunhes, J. 1977a. Les moustiques de l’archipel des Comores I. - Inventaire, &partition et description de quatre esptces ou sous-espscies...nouvelles. Cah. O.R.S.T.O.M. Ser. Entomol. Med. Parasitol. 15:131-152. Brunhes, J. 1977b. Les moustiques de l’archipel des Comores 11. - Description de...Dieng. 1978. Aedes (Stegomyia) neoafricanus un nouvelle espzcie de moustique capture’e au Sgne’gal Oriental (Diptera: Culicidae), Cah. O.R.S.T.O.M
de Souza, A S; Couri, M S; Florindo, L
The effects of industrial anthropization on species composition and community diversity of Culicidae (Diptera) were studied in a mangrove area impacted by industrial activities as compared to a preserved area, both around Guanabara Bay in the state of Rio de Janeiro, Brazil. Diversity, equitability, and species richness in Culicidae community differed between the studied areas. Indicator species analysis and correspondence analysis were carried out and indicated that the Sabethini, especially Wyeomyia (Phoniomyia) theobaldi Lane, Wyeomyia (Phoniomyia) fuscipes (Edwards), and a non-identified species of Wyeomyia sp. were associated to the preserved area, whereas Aedes taeniorhynchus Wiedemann and Aedes scapularis (Rondani) to the impacted area.
Mário Luís Pessôa Guedes
Full Text Available Mosquito community composition in dynamic landscapes from the Atlantic Forest biome (Diptera, Culicidae. Considering that some species of Culicidae are vectors of pathogens, both the knowledge of the diversity of the mosquito fauna and how some environment factors influence in it, are important subjects. In order to address the composition of Culicidae species in a forest reserve in southern Atlantic Forest, we compared biotic and abiotic environmental determinants and how they were associated with the occurrence of species between sunset and sunrise. The level of conservation of the area was also considered. The investigation was carried out at Reserva Natural do Morro da Mina, in Antonina, state of Paraná, Brazil. We performed sixteen mosquito collections employing Shannon traps at three-hour intervals, from July 2008 to June 2009. The characterization of the area was determined using ecological indices of diversity, evenness, dominance and similarity. We compared the frequency of specimens with abiotic variables, i.e., temperature, relative humidity and pluviosity. Seven thousand four hundred ten mosquito females were captured. They belong to 48 species of 12 genera. The most abundant genera were Anopheles, Culex, Coquillettidia, Aedes and Runchomyia. Among the species, the most abundant was Anopheles cruzii, the primary vector of Plasmodium spp. in the Atlantic Forest. Results of the analyses showed that the abiotic variables we tested did not influence the occurrence of species, although certain values suggested that there was an optimum range for the occurrence of culicid species. It was possible to detect the presence of species of Culicidae with different epidemiologic profiles and habitat preference.
Reiter, M.E.; Lapointe, D.A.
Effective management of avian malaria (Plasmodium relictum) in Hawai'i's endemic honeycreepers (Drepanidinae) requires the identification and subsequent reduction or treatment of larval habitat for the mosquito vector, Culex quinquefasciatus (Diptera: Culicidae). We conducted ground surveys, treehole surveys, and helicopter aerial surveys from 20012003 to identify all potential larval mosquito habitat within two 100+ ha mesic-dry forest study sites in Hawai'i Volcanoes National Park, Hawai'i; 'Ainahou Ranch and Mauna Loa Strip Road. At 'Ainahou Ranch, anthropogenic sites (43%) were more likely to contain mosquitoes than naturally occurring (8%) sites. Larvae of Cx. quinquefasciatus were predominately found in anthropogenic sites while Aedes albopictus larvae occurred less frequently in both anthropogenic sites and naturally-occurring sites. Additionally, moderate-size (???20-22,000 liters) anthropogenic potential larval habitat had >50% probability of mosquito presence compared to larger- and smaller-volume habitat (malaria, may be controlled by larval habitat reduction in the mesic-dry landscapes of Hawai'i where anthropogenic sources predominate.
Identification and transcription profiling of NDUFS8 in Aedes taeniorhynchus (Diptera: Culicidae): developmental regulation and environmental response...7205 Email firstname.lastname@example.org Abstract: The cDNA of a NADH dehydrogenase-ubiquinone Fe-S protein 8 subunit (NDUFS8) gene from Aedes (Ochlerotatus...information useful for developing dsRNA pesticide for mosquito control. Keywords: Aedes taeniorhynchus, AetNDUFS8, mRNA expression, development
Govindarajan, M.; Rajeswary, M.; Sivakumar, R.
Background & objectives: In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal and ovicidal potential of the crude hexane, benzene, chloroform, ethyl acetate and methanol solvent extracts from the medicinal plant Pithecellobium dulce against the mosquito vectors, Anopheles stephensi and Aedes aegypti (Diptera: Culicidae). Methods: Larvicidal activity of P. dulce plant...
Vaughan, Jefferson A; Bell, Jeffrey A; Turell, Michael J; Chadee, Dave D
When virus and microfilariae are ingested concurrently by a mosquito, microfilariae (mf) may penetrate the mosquito midgut and introduce virus directly into the mosquito hemocoel, allowing mosquitoes to become infectious much sooner than normal and enhancing transmission of viruses by mosquitoes. Mansonella ozzardi (Manson) is a benign filarial nematode parasite of humans in Latin America and is transmitted by black flies (Diptera: Simuliidae) and biting midges (Diptera: Ceratopogonidae). Because M. ozzardi and dengue are sympatric, we wanted to know whether M. ozzardi mf had the ability to penetrate the midgut of Aedes aegypti (L.) (Diptera: Culicidae) and thus play a potential role in the enhancement of dengue transmission. To test this, the F1 progeny from locally collected Ae. aegypti were fed on M. ozzardi-infected human males in an endemic village in northern Trinidad. Mosquitoes were dissected at various times after feeding and examined for mf in the midguts and thoraces. Microfilariae penetrated the midguts of 43% of 63 mosquitoes that ingested mf. Overall, 11% of mf penetrated the midgut by 17 h after being ingested. The intensity of midgut penetration was positively correlated to the numbers of mf ingested. Because midgut penetration is a key requirement for mf enhancement to occur, the potential exists that M. ozzardi could be involved in the enhancement of dengue virus transmission.
Brasileira de Malariologia e Doenças Tropicais 16, 329–348. Forattini, O.P. (1962) Entomologia médica. Parte geral, Diptera, Anophelini. Vol.1...Estado do Espírito Santo, Brasil. Revista Brasileira de Entomologia 52, 671–673. Schultz, J., Müller, T., Achtziger, M., Seibel, P.N., Dandekar, T
Qualls, Whitney A; Day, Jonathan F; Xue, Rui-De; Bowers, Doria F
Aedes aegypti (L.) (Diptera: Culicidae) female mosquitoes infected systemically with Sindbis virus (SINV) took longer than uninfected mosquitoes to locate and fully engorge on blood. On days 7 and 14 postexposure, blood feeding took 1.3 and 1.5 times longer in mosquitoes with a disseminated SINV infection, respectively. SINV dissemination did not affect the average weight of unfed Ae. aegypti, but did result in a 10 and 12% increase in blood imbibed compared with mosquitoes without a positive SINV dissemination and non-SINV-exposed mosquitoes, respectively. Ae. aegypti mosquitoes with a disseminated SINV infection fed an average of 4 h sooner than uninfected mosquitoes when offered a bloodmeal contained inside a DEET (N,N-diethyl-3-methylbenzamide) saturated (30%) bovine sausage casing. Together, these results indicate that behavioral changes in mosquito host-seeking, blood feeding and sensitivity to DEET occurred in mosquitoes after SINV infection and dissemination.
Barnard, Donald R; Xue, Rui-De; Rotstein, Margaret A; Becnel, James J
Infection of Aedes aegypti (L.) (Diptera: Culicidae) with Edhazardia aedis (Microsporidia: Culicosporidae) reduced mean human host attraction and landing/probing rates in female mosquitoes by 53 and 62%, respectively, compared with rates in microsporidia-free females. Infection with E. aedis reduced the average weight of unfed female mosquitoes by 4%, caused them to imbibe 23% less blood, and to lay 30% fewer eggs than healthy females. In contrast, E. aedis-infected mosquitoes required 20% more time (>1 h) than healthy females to bite skin treated with 15% DEET. Statistically significant morbidity in E. aedis-infected females was indicated by reductions in host attraction and landing/probing responses, the mass of unfed and blood-engorged females, and fecundity, and by increased DEET repellency.
Fischer, Dominik; Thomas, Stephanie Margarete; Niemitz, Franziska; Reineking, Björn; Beierkuhnlein, Carl
During the last decades the disease vector Aedes albopictus ( Ae. albopictus) has rapidly spread around the globe. The spread of this species raises serious public health concerns. Here, we model the present distribution and the future climatic suitability of Europe for this vector in the face of climate change. In order to achieve the most realistic current prediction and future projection, we compare the performance of four different modelling approaches, differentiated by the selection of climate variables (based on expert knowledge vs. statistical criteria) and by the geographical range of presence records (native range vs. global range). First, models of the native and global range were built with MaxEnt and were either based on (1) statistically selected climatic input variables or (2) input variables selected with expert knowledge from the literature. Native models show high model performance (AUC: 0.91-0.94) for the native range, but do not predict the European distribution well (AUC: 0.70-0.72). Models based on the global distribution of the species, however, were able to identify all regions where Ae. albopictus is currently established, including Europe (AUC: 0.89-0.91). In a second step, the modelled bioclimatic envelope of the global range was projected to future climatic conditions in Europe using two emission scenarios implemented in the regional climate model COSMO-CLM for three time periods 2011-2040, 2041-2070, and 2071-2100. For both global-driven models, the results indicate that climatically suitable areas for the establishment of Ae. albopictus will increase in western and central Europe already in 2011-2040 and with a temporal delay in eastern Europe. On the other hand, a decline in climatically suitable areas in southern Europe is pronounced in the Expert knowledge based model. Our projections appear unaffected by non-analogue climate, as this is not detected by Multivariate Environmental Similarity Surface analysis. The generated risk maps
Full Text Available Although they are important disease vectors mosquito biodiversity in Pakistan is poorly known. Recent epidemics of dengue fever have revealed the need for more detailed understanding of the diversity and distributions of mosquito species in this region. DNA barcoding improves the accuracy of mosquito inventories because morphological differences between many species are subtle, leading to misidentifications.Sequence variation in the barcode region of the mitochondrial COI gene was used to identify mosquito species, reveal genetic diversity, and map the distribution of the dengue-vector species in Pakistan. Analysis of 1684 mosquitoes from 491 sites in Punjab and Khyber Pakhtunkhwa during 2010-2013 revealed 32 species with the assemblage dominated by Culex quinquefasciatus (61% of the collection. The genus Aedes (Stegomyia comprised 15% of the specimens, and was represented by six taxa with the two dengue vector species, Ae. albopictus and Ae. aegypti, dominant and broadly distributed. Anopheles made up another 6% of the catch with An. subpictus dominating. Barcode sequence divergence in conspecific specimens ranged from 0-2.4%, while congeneric species showed from 2.3-17.8% divergence. A global haplotype analysis of disease-vectors showed the presence of multiple haplotypes, although a single haplotype of each dengue-vector species was dominant in most countries. Geographic distribution of Ae. aegypti and Ae. albopictus showed the later species was dominant and found in both rural and urban environments.As the first DNA-based analysis of mosquitoes in Pakistan, this study has begun the construction of a barcode reference library for the mosquitoes of this region. Levels of genetic diversity varied among species. Because of its capacity to differentiate species, even those with subtle morphological differences, DNA barcoding aids accurate tracking of vector populations.
Mosquitoes transmit pathogens that cause millions of human deaths each year. Dengue virus is transmitted to humans in tropical and subtropical areas by Aedes aegypti (Diptera: Culicidae). The use of synthetic insecticides to control this mosquito is accompanied by high operational costs and adverse...
Versteirt, V; Boyer, S; Damiens, D; De Clercq, E M; Dekoninck, W; Ducheyne, E; Grootaert, P; Garros, C; Hance, T; Hendrickx, G; Coosemans, M; Van Bortel, W
To advance our restricted knowledge on mosquito biodiversity and distribution in Belgium, a national inventory started in 2007 (MODIRISK) based on a random selection of 936 collection points in three main environmental types: urban, rural and natural areas. Additionally, 64 sites were selected because of the risk of importing a vector or pathogen in these sites. Each site was sampled once between May and October 2007 and once in 2008 using Mosquito Magnet Liberty Plus traps. Diversity in pre-defined habitat types was calculated using three indices. The association between species and environmental types was assessed using a correspondence analysis. Twenty-three mosquito species belonging to traditionally recognized genera were found, including 21 indigenous and two exotic species. Highest species diversity (Simpson 0.765) and species richness (20 species) was observed in natural areas, although urban sites scored also well (Simpson 0.476, 16 species). Four clusters could be distinguished based on the correspondence analysis. The first one is related to human modified landscapes (such as urban, rural and industrial sites). A second is composed of species not associated with a specific habitat type, including the now widely distributed Anopheles plumbeus. A third group includes species commonly found in restored natural or bird migration areas, and a fourth cluster is composed of forest species. Outcomes of this study demonstrate the effectiveness of the designed sampling scheme and support the choice of the trap type. Obtained results of this first country-wide inventory of the Culicidae in Belgium may serve as a basis for risk assessment of emerging mosquito-borne diseases.
Chen, Kai; Wang, Yan; Li, Xiang-Yu; Peng, Heng; Ma, Ya-Jun
Anopheles sinensis (Diptera: Culicidae) is a primary vector of Plasmodium vivax and Brugia malayi in most regions of China. In addition, its phylogenetic relationship with the cryptic species of the Hyrcanus Group is complex and remains unresolved. Mitochondrial genome sequences are widely used as molecular markers for phylogenetic studies of mosquito species complexes, of which mitochondrial genome data of An. sinensis is not available. An. sinensis samples was collected from Shandong, China, and identified by molecular marker. Genomic DNA was extracted, followed by the Illumina sequencing. Two complete mitochondrial genomes were assembled and annotated using the mitochondrial genome of An. gambiae as reference. The mitochondrial genomes sequences of the 28 known Anopheles species were aligned and reconstructed phylogenetic tree by Maximum Likelihood (ML) method. The length of complete mitochondrial genomes of An. sinensis was 15,076 bp and 15,138 bp, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and an AT-rich control region. As in other insects, most mitochondrial genes are encoded on the J strand, except for ND5, ND4, ND4L, ND1, two rRNA and eight tRNA genes, which are encoded on the N strand. The bootstrap value was set as 1000 in ML analyses. The topologies restored phylogenetic affinity within subfamily Anophelinae. The ML tree showed four major clades, corresponding to the subgenera Cellia, Anopheles, Nyssorhynchus and Kerteszia of the genus Anopheles. The complete mitochondrial genomes of An. sinensis were obtained. The number, order and transcription direction of An. sinensis mitochondrial genes were the same as in other species of family Culicidae.
Zahirnia A H
Full Text Available Introduction: Insects as the largest category of arthropods include numerous groups and families that the most important of them belong to order Diptera, family Culicidae. Because of feeding on the human's blood, a number of species of this family have been known as responsible for the transmission of pathogens for many diseases such as malaria, filariasis, encephalitis, yellow fever and dengue fever in the world. Given that no research has been conducted to determine the fauna of existing mosquitoes in the city of Poldokhtar, Lorestan Province, the present study aimed to exactly determine the mosquitoes' fauna in this city to perform appropriate prevention measures. Methods: In this faunistic and cross-sectional descriptive study, four urban areas and four rural areas in four geographic directions in the city of Poldokhtar were determined. In each urban area, two places and in each designated rural area, four places including two human places and two animal places were selected. From the early of April 2015 to the early of January 2016, larvae, pupae and adult mosquitoes of the Culicidae family were collected. Sampling methods for larvae, pupae and mature were ladling, night catch, total and hand catch with an aspirator. Characteristics including the name of the collector, date of collection, code related to habitat, habitat status (permanent or temporary, type of vegetation cover, type of substrate, and the situation of sunlight were recorded in the related form. The samples were identified by resources and valid identification keys. The data were analyzed using the SPSS software version 19. Results: Totally, 5392 mosquito adults of the Culicidae family including 1818 mosquito adults and 3574 larvae in designated areas in the city as well as four rural areas were collected. The three genera Anopheles (21.9%, Culex (64.6%, and Culiseta (13.5% were diagnosed. Also, from three genera, 12 species were identified as follows: Culex theiler, Cx
Trari, Bouchra; Dakki, Mohamed; Harbach, Ralph E
An updated checklist of the mosquito species (Diptera: Culicidae) recorded in Morocco from 1916 to 2016 is provided, including synonyms and synonymous usage for each species. Forty-three species belonging to seven genera are recorded so far: Anopheles (9), Aedes (12) Coquillettidia (2), Culex (12), Culiseta (5), Orthopodomyia (1) and Uranotaenia (2). Traditional and equivalent names in the polyphyletic concept of Aedes are provided for the aedine species. The historical importance and current potential threat of mosquitoes to human health in Morocco is reviewed. © 2017 The Society for Vector Ecology.
Santos,Cleandson Ferreira; Borges,Magno
AbstractINTRODUCTION: This study evaluated the effects of cattle removal on the Culicidae mosquito community structure in a tropical dry forest in Brazil.METHODS: Culicidae were collected during dry and wet seasons in cattle presence and absence between August 2008 and October 2010 and assessed using multivariate statistical models.RESULTS: Cattle removal did not significantly alter Culicidae species richness and abundance. However, alterations were noted in Culicidae community composition.CO...
Dunbar, Mike W; Bachmann, Amanda; Varenhorst, Adam J
Mosquito abatement programs in Midwestern communities frequently exist within landscapes dominated by agriculture. Although separately managed, both agricultural pests and mosquitoes are targeted by similar classes of insecticides. As a result, there is the potential for unintended insecticide exposure to mosquito populations from agricultural pest management. To determine the impact that agricultural management practices have on mosquito insecticide susceptibility we compared the mortality of Aedes vexans (Meigen; Diptera: Culicidae) between populations sampled from locations with and without mosquito abatement in South Dakota, a region dominated by agricultural production. Collection locations were either within towns with mosquito abatement programs (n = 2; Brookings and Sioux Falls, SD) or located > 16 km from towns with mosquito abatement programs (n = 2; areas near Harrold and Willow Lake, SD). WHO bioassays were used to test susceptibly of adults to differing insecticide classes relative to their respective controls; 1) an organochlorine (dieldrin 4%), 2) an organophosphate (malathion 5%), and 3) a pyrethroid (lambda-cyhalothrin 0.05%). Corrected mortality did not significantly differ between locations with or without abatement; however, when locations were analized by proportion of developed land within the surrounding landscape pyrethroid mortality was significantly lower where crop production dominated the surrounding landscape and mosquito abatement was present. These data suggest that agricultural pest management may incidentally contribute to reduced mosquito susceptibility where overlap between agricultural pest management and mosquito abatement exists. Decoupling insecticide classes used by both agricultural and public health pest management programs may be necessary to ensure continued efficacy of pest management tools.
Berec, Ludĕk; Gelbic, Ivan; Sebesta, Oldrich
An understanding of how climate variables drive seasonal dynamics of mosquito populations is critical to mitigating negative impacts of potential outbreaks, including both nuisance effects and risk of mosquito-borne infectious disease. Here, we identify climate variables most affecting seasonal dynamics of two major floodwater mosquitoes, Aedes vexans (Meigen, 1830) and Aedes sticticus (Meigen, 1838) (Diptera: Culicidae), along the lower courses of the Dyje River, at the border between the Czech Republic and Austria. Monthly trap counts of both floodwater mosquitoes varied both across sites and years. Despite this variability, both models used to fit the observed data at all sites (and especially that for Ae. sticticus) and site-specific models fitted the observed data quite well. The most important climate variables we identified-temperature and especially flooding-were driving seasonal dynamics of both Aedes species. We suggest that flooding determines seasonal peaks in the monthly mosquito trap counts while temperature modulates seasonality in these counts. Hence, floodwater mosquitoes indeed appear worthy of their name. Moreover, the climate variables we considered for modeling were able reasonably to predict mosquito trap counts in the month ahead. Our study can help in planning flood management; timely notification of people, given that these mosquitoes are a real nuisance in this region; public health policy management to mitigate risk from such mosquito-borne diseases as that caused in humans by the Tahyna virus; and anticipating negative consequences of climate change, which are expected only to worsen unless floods, or the mosquitoes themselves, are satisfactorily managed.
Yamamoto, Daisuke S; Hatakeyama, Masatsugu; Matsuoka, Hiroyuki
In the past decade, many transgenic lines of mosquitoes have been generated and analyzed, whereas the maintenance of a large number of transgenic lines requires a great deal of effort and cost. In vitro fertilization by an injection of cryopreserved sperm into eggs has been proven to be effective for the maintenance of strains in mammals. The technique of artificial egg activation is a prerequisite for the establishment of in vitro fertilization by sperm injection. We demonstrated that artificial egg activation is feasible in the malaria vector mosquito, Anopheles stephensi (Diptera, Culicidae). Nearly 100% of eggs dissected from virgin females immersed in distilled water darkened, similar to normally oviposited fertilized eggs. It was revealed by the cytological examination of chromosomes that meiotic arrest was relieved in these eggs approximately 20 min after incubation in water. Biochemical examinations revealed that MAPK (mitogen-activated protein kinase)/ERK (extracellular signal-regulated protein kinase) and MEK (MAPK/ERK kinase) were dephosphorylated similar to that in fertilized eggs. These results indicate that dissected unfertilized eggs were activated in distilled water and started development. Injection of distilled water into body cavity of the virgin blood-fed females also induced activation of a portion of eggs in the ovaries. The technique of artificial egg activation is expected to contribute to the success of in vitro fertilization in A. stephensi.
Rosângela MR Barbosa
Full Text Available An ovitrap (BR-OVT based on physical and chemical stimuli for attracting gravid Culex quinquefasciatus (Diptera: Culicidae females was developed and evaluated under laboratory and field conditions. Attractants were assayed using alternative chamber bioassays prior to being used in the BR-OVT oviposition trap. A significant preference of gravid females for sites containing conspecific egg rafts was observed, as a response to the natural oviposition pheromone, as well as for sites treated with the synthetic pheromone erythro-6-acetoxy-5-hexadecanolide. Five- to 20-day old grass infusion was strongly attractive to gravid females for laying eggs. On the other hand, entomopathogenic Bacillus sphaericus (Bs did not influence the choice of an oviposition site when used in combination with grass infusion and can therefore be used as a larvicide in ovitraps. Results from field trials showed that the BR-OVT with grass infusion and with or without Bs works as a preferred oviposition site for Cx. quinquefasciatus. The BR-OVT was more effective for egg collection when placed indoors and comparison with the number of egg rafts laid in cesspits over 40 days indicates that this very simple ovitrap may be a useful tool for monitoring populations of the most important of the vectors of bancroftian filariasis.
Full Text Available ABSTRACT Near-infrared spectroscopy and microstructure of the scales of Sabethes (Sabethes albiprivus (Diptera: Culicidae. Sabethes (Sabethes albiprivus Theobald individuals vary considerably in size and color of the reflections of the scales on their thorax, abdomen, antepronotal lobes and occiput. The goal of this study was to investigate and to characterize the differences in the color of the scales among preserved specimens and to analyze the differences in the microstructures of the scales that cover their bodies using near-infrared spectroscopy, and to evaluate whether the latter is efficient in distinguishing the populations. A total of 201 adult females were analyzed for the characterization of color patterns. In addition, absorbance spectra and scanning electron microscope images were obtained from them. As a result of color analysis, two variations were identified, one represented by specimens with yellow or green scales and the other with blue or purple scales. The same two variations were corroborated using NIRS. Analysis of the microstructure of the scales lining the mesonotum, occiput and antepronotal lobes resulted in the same variations. The three methodologies, near-infrared spectroscopy, scanning electron microscopy and coloration of the reflections of the scales revealed two variations within Sa. albiprivus.
Naddaf, Saied Reza; Razavi, Mohammad Reza; Bahramali, Golnaz
Anopheles fluviatilis James (Diptera: Culicidae) is one of the known malaria vectors in south and southeastern Iran. Earlier ITS2 sequences analysis of specimens from Iran demonstrated only a single genotype that was identical to species Y in India, which is also the same as species T. We identified 2 haplotypes in the An. fluviatilis populations of Iran based on differences in nucleotide sequences of D3 domain of the 28S locus of ribosomal DNA (rDNA). Comparison of sequence data from 44 Iranian specimens with those publicly available in the Genbank database showed that all of the 28S-D3 sequences from Kazeroun and Khesht regions in Fars Province were identical to the database entry representing species U in India. In other regions, all the individuals showed heterozygosity at the single nucleotide position, which identifies species U and T. It is argued that the 2 species may co-occur in some regions and hybridize; however, the heterozygosity in the 28S-D3 locus was not reflected in ITS2 sequences and this locus for all individuals was identical to species T. This study shows that in a newly diverged species, like members of An. fluviatilis complex, a single molecular marker may not be sufficiently discriminatory to identify all the taxa over a vast geographical area. In addition, other molecular markers may provide more reliable information for species discrimination.
Alencar, Jeronimo; Silva, Júlia dos Santos; de Oliveira, Luis Claudio Motta; Marcondes, Carlos Brisola; Morone, Fernanda; Lorosa, Elias Seixas
Blood-feeding sources of Culex quinquefasciatus Say (Diptera: Culicidae) collected in the eastern region of the Brazilian state of Santa Catarina were analyzed by precipitin technique. One hundred fifty-four female mosquitoes collected by CDC traps in the Navegantes municipality 13-15 February 2005 reacted to one or more of eight antisera, including chicken, dog, goat, sheep, horse, opossum, human and rodent antisera. One hundred thirty-seven specimens (89%) reacted to only one source, and 17 (11%) specimens reacted to two sources. Among the 137 specimens reacting to only one source, reactions to rodent (50.4%), sheep (5.8%), chicken (5.1%), goat (5.1%), dog (2.2%), horse (3.6%), and human (3.6%) antisera were observed. The analyzed species demonstrated a high degree of opportunistic feeding behavior in relation to host preference. Results are compared with results from similar studies, and the low proportion of reactions to human antisera is discussed.
Full Text Available Objective: To evaluate the activity of spiromesifen against the most abundant and investigated mosquito species, Culiseta longiareolata Aitken, 1954 (Diptera, Culicidae. Methods: Culiseta longiareolata larvae were collected from untreated areas located at TÃ©bessa (Northeast Algeria. A commercial formulation of spiromesifen (OberonÂ® 240 SC was tested at different concentrations ranging between 238 and 1428Â Î¼g/L on newly molted fourth-instar larvae under standard laboratory conditions according to Word Health Organization recommendations. The effects were examined on the mortality, the morphometric measurements, two biomarkers (catalase and malondialdehyde, and the biochemical composition of larvae, respectively. Results: The compound exhibited insecticidal activity. Moreover, it disturbed growth and several morphological aberrations were observed. It also affected body volume, biomarkers and contents of carbohydrates, lipids and proteins. A marked effect on lipids and malondialdehyde was noted, confirming its primary mode of action on lipid synthesis. Conclusions: Spiromesifen appears less potent than other insecticides tested such as the insect growth disruptors. Keywords: Culiseta longiareolata, Spiromesifen, Toxicity, Biochemical composition, Biomarkers
João Antonio C. Zequi
Full Text Available Development of the immature stages of Culex (Culex saltanensis Dyar (Diptera, Culicidae under laboratory conditions. Culex (Culex saltanensis Dyar, 1928 is becoming frequent and abundant in natural and artificial breeding sites in urban and rural areas of Brazil. This study contributes to the knowledge of the biology of a Brazilian strain of C. saltanensis. The development of specimens reared individually or grouped was observed. The study was conducted at a constant temperature of 27 ± 2°C, 14L:10D photoperiod and 80 ± 5% relative humidity. The immature stages were observed every 6 hours until adult emergence, which occurred in 12.29 days among individually reared specimens and in 13.12 days among group-reared specimens. Egg rafts for the experiment were obtained from the laboratory and field. Eggs hatched at a rate of 97.48 ± 2.32%. More eggs per egg raft were obtained from the field than from the laboratory. Males from individually reared specimens emerged in 12.29 ± 1.11 days and females in 13.12 ± 1.58 days. The male-female ratio was 1:1. Larval survival rate was higher than 85% for larvae reared isolated and higher than 95% for group-reared larvae. The Culex saltanensis life cycle was completed within 12 to 14 days, where larval instars I and IV took the most time to develop and the pupae, the shortest.
Cleandson Ferreira Santos
Full Text Available AbstractINTRODUCTION: This study evaluated the effects of cattle removal on the Culicidae mosquito community structure in a tropical dry forest in Brazil.METHODS: Culicidae were collected during dry and wet seasons in cattle presence and absence between August 2008 and October 2010 and assessed using multivariate statistical models.RESULTS: Cattle removal did not significantly alter Culicidae species richness and abundance. However, alterations were noted in Culicidae community composition.CONCLUSIONS: This is the first study to evaluate the impact of cattle removal on Culicidae community structure in Brazil and demonstrates the importance of assessing ecological parameters such as community species composition.
Santos, Cleandson Ferreira; Borges, Magno
This study evaluated the effects of cattle removal on the Culicidae mosquito community structure in a tropical dry forest in Brazil. Culicidae were collected during dry and wet seasons in cattle presence and absence between August 2008 and October 2010 and assessed using multivariate statistical models. Cattle removal did not significantly alter Culicidae species richness and abundance. However, alterations were noted in Culicidae community composition. This is the first study to evaluate the impact of cattle removal on Culicidae community structure in Brazil and demonstrates the importance of assessing ecological parameters such as community species composition.
BANGOURA and A. LORAND. 1979. Isolements d’arbovirus au Senegal oriental a partir de moustiques (1972-1977) et notes sur l’epidemiologie des virus...Dengue 2 au Senegal oriental: Une poussee epizootioque en milieu selvatique; isolements du virus a partir de moustiques et d’un singe et...neoafticanus une nouvelle espece de moustique capturee au Senegal Oriental (Diptera: Culicidae). Cah. O.R.S.T.O.M. Ser. Entomol. Med. Parasitol. 16
Pathol. Exot. 53: 531-542. 1968. Contribution a I’etude des moustiques du Maroc (Diptera, Culicidae) six especes nouvelles pour le pays. Cah. ORSTOM...quelques moustiques du Maroc. Arch. inst. Pasteur Maroc 2: 361-365. 1957. Sur Culex torrentium Martini. Ann. Parasitol. Hum. Comp. 32: 438-442...De Grandpre, A.D. and D. D’E. De Charmoy 1900(1901). Les moustiques : anatomie et biologie. Contribution a I’etude des Culicides et principalement
major vector of malaria in China ; however, its vectorial capacity is unknown in the ROK. The other remaining four Anopheles species are not considered to...morphometry and morphology of Anopheles aconitus Form B and C eggs under scanning electron microscope. Revista do Instituto de Medicina Tropical de Sao Paulo...and its genetic identity with An. (Ano.) anthropophagus from China (Diptera: Culicidae). Zootaxa, 378, 1–14. RUEDA ET AL.40 · Zootaxa 2268 © 2009
Dengue Vector, Aedes aegypti (Diptera: Culicidae) JAMES F. HARWOOD,1,2 MUHAMMAD FAROOQ,1 ALEC G. RICHARDSON,1 CARL W. DOUD,1 JOHN L. PUTNAM,3 DANIEL E...vector, Aedes aegypti (L.), inside human habitations must be performed quickly and efÞciently to reduce the risk of transmission during dengue...immediate knockdown of vector populations that may lower the risk of infection and allow other suppression strategies to be implemented. KEY WORDS Aedes
Vadivalagan, Chithravel; Karthika, Pushparaj; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Del Serrone, Paola; Benelli, Giovanni
Culex quinquefasciatus (Diptera: Culicidae) is a vector of many pathogens and parasites of humans, as well as domestic and wild animals. In urban and semi-urban Asian countries, Cx. quinquefasciatus is a main vector of nematodes causing lymphatic filariasis. In the African region, it vectors the Rift Valley fever virus, while in the USA it transmits West Nile, St. Louis encephalitis and Western equine encephalitis virus. In this study, DNA barcoding was used to explore the genetic variation of Cx. quinquefasciatus populations from 88 geographical regions. We presented a comprehensive approach analyzing the effectiveness of two gene markers, i.e. CO1 and 16S rRNA. The high threshold genetic divergence of CO1 (0.47%) gene was reported as an ideal marker for molecular identification of this mosquito vector. Furthermore, null substitutions were lower in CO1 if compared to 16S rRNA, which influenced its differentiating potential among Indian haplotypes. NJ tree was well supported with high branch values for CO1 gene than 16S rRNA, indicating ideal genetic differentiation among haplotypes. TCS haplotype network revealed 14 distinct clusters. The intra- and inter-population polymorphism were calculated among the global and Indian Cx. quinquefasciatus lineages. The genetic diversity index Tajima' D showed negative values for all the 4 intra-population clusters (G2-4, G10). Fu's FS showed negative value for G10 cluster, which was significant and indicated recent population expansion. However, the G2-G4 (i.e. Indian lineages) had positive values, suggesting a bottleneck effect. Overall, our research firstly shed light on the genetic differences among the haplotypes of Cx. quinquefasciatus species complex, adding basic knowledge to the molecular ecology of this important mosquito vector. Copyright © 2017 Elsevier B.V. All rights reserved.
Bisset, J A; Marín, R; Rodríguez, M M; Severson, D W; Ricardo, Y; French, L; Díaz, M; Pérez, O
Dengue (family Flaviridae, genus Flavivirus, DENV) and dengue hemorrhagic fever (DHF) are presently important public health problems in Costa Rica. The primary strategy for disease control is based on reducing population densities of the main mosquito vector Aedes aegypti (L.) (Diptera: Culicidae). This is heavily dependent on use of chemical insecticides, thus the development of resistance is a frequent threat to control program effectiveness. The objective of this study was to determine the levels of insecticide resistance and the metabolic resistance mechanisms involved in two Ae. aegypti strains collected from two provinces (Puntarenas and Limon) in Costa Rica. Bioassays with larvae were performed according to World Health Organization guidelines and resistance in adults was measured through standard bottle assays. The activities of beta-esterases, cytochrome P450 monooxygenases, and glutathione S-transferases (GST), were assayed through synergists and biochemical tests, wherein the threshold criteria for each enzyme was established using the susceptible Rockefeller strain. The results showed higher resistance levels to the organophosphate (OP) temephos and the pyrethroid deltamethrin in larvae. The efficacy of commercial formulations of temephos in controlling Ae. aegypti populations was 100% mortality up to 11 and 12 d posttreatment with daily water replacements in test containers. Temephos and deltamethrin resistance in larvae were associated with high esterase activity, but not to cytochrome P450 monooxygenase or GST activities. Adult mosquitoes were resistant to deltamethrin, and susceptible to bendiocarb, chlorpyrifos, and cypermethrin. Because temephos and deltamethrin resistance are emerging at the studied sites, alternative insecticides should be considered. The insecticides chlorpyrifos and cypermethrin could be good candidates to use as alternatives for Ae. aegypti control.
Lebl, Karin; Zittra, Carina; Silbermayr, Katja; Obwaller, Adelheid; Berer, Dominik; Brugger, Katharina; Walter, Melanie; Pinior, Beate; Fuehrer, Hans-Peter; Rubel, Franz
Mosquitoes (Diptera: Culicidae) are important vectors for a wide range of pathogenic organisms. As large parts of the human population in developed countries live in cities, the occurrence of vector-borne diseases in urban areas is of particular interest for epidemiologists and public health authorities. In this study, we investigated the mosquito occurrence in the city of Vienna, Austria, in order to estimate the risk of transmission of mosquito-borne diseases. Mosquitoes were captured using different sampling techniques at 17 sites in the city of Vienna. Species belonging to the Culex pipiens complex (78.8 %) were most abundant, followed by Coquillettidia richiardii (10.2 %), Anopheles plumbeus (5.4 %), Aedes vexans (3.8 %), and Ochlerotatus sticticus (0.7 %). Individuals of the Cx. pipiens complex were found at 80.2 % of the trap sites, while 58.8 % of the trap sites were positive for Cq. richiardii and Ae. vexans. Oc. sticticus was captured at 35.3 % of the sites, and An. plumbeus only at 23.5 % of the trap sites. Cx. pipiens complex is known to be a potent vector and pathogens like West Nile virus (WNV), Usutu virus (USUV), Tahyna virus (TAHV), Sindbis virus (SINV), Plasmodium sp., and Dirofilaria repens can be transmitted by this species. Cq. richiardii is a known vector species for Batai virus (BATV), SINV, TAHV, and WNV, while Ae. vexans can transmit TAHV, USUV, WNV, and Dirofilaria repens. An. plumbeus and Oc. sticticus seem to play only a minor role in the transmission of vector-borne diseases in Vienna. WNV, which is already wide-spread in Europe, is likely to be the highest threat in Vienna as it can be transmitted by several of the most common species, has already been shown to pose a higher risk in cities, and has the possibility to cause severe illness.
Ana Cristina Tissot
Full Text Available A Coleção de Entomologia do Departamento de Zoologia da Universidade Federal do Paraná (DZUP abriga cerca de 5.000.000 de exemplares de insetos. A coleção de Diptera está representada por aproximadamente 2.000.000 de exemplares, sendo Muscidae; Culicidae e Syrphidae as famílias mais representativas. A ordem Diptera possui cerca de 150.000 espécies descritas e a coleção conta com cerca de 103.000 exemplares representantes de 78 famílias. A lista das espécies pertencentes à família Culicidae conta com 9.579 exemplares, distribuídos em 2 subfamílias, 7 tribos, 17 gêneros, 26 subgêneros e 85 espécies. A maioria dos exemplares foi coletado em remanescentes de mata localizados em áreas urbanas e rurais, ambientes silvestres e urbanos de regiões litorâneas ou áreas urbanas pertencentes a diferentes cidades do Estado do Paraná, e algumas espécies incluídas foram capturadas nos Estados de São Paulo, Mato Grosso, Santa Catarina e no Distrito Federal. As informações específicas de cada exemplar, como local de coleta, latitude, longitude, coletor, data de coleta, método de coleta e nome do pesquisador que identificou, e também informações taxonômicas como ordem, tribo, gênero, subgênero e espécie, foram informatizados em um banco de dados.The Entomological Collection of Departamento de Zoologia of Universidade Federal do Paraná (DZUP accommodates about 5,000,000 insect specimens. The collection of Diptera is represented by approximately 2,000,000 specimens, being Muscidae, Culicidae and Syrphidae the most representative families. The Diptera order consists of approximately 150,000 described species and in the Collection about 103,000 specimens within 78 families are registered. The list of species of the family Culicidae presents 9,579 specimens within 2 subfamilies, 7 tribes, 17 genera, 26 subgenera and 85 species. Most specimens were captured in forest remnants in urban and rural areas, wild and urban environments in
Mint Lekweiry, Khadijetou; Ould Ahmedou Salem, Mohamed Salem; Ould Brahim, Khyarhoum; Ould Lemrabott, Mohamed Aly; Brengues, Cécile; Faye, Ousmane; Simard, Frédéric; Ould Mohamed Salem Boukhary, Ali
Aedes aegypti L. (Diptera: Culicidae) is a major vector of yellow fever, dengue, and chikungunya viruses throughout tropical and subtropical areas of the world. Although the southernmost part of Mauritania along the Senegal river has long been recognized at risk of yellow fever transmission, Aedes spp. mosquitoes had never been reported northwards in Mauritania. Here, we report the first observation of Aedes aegypti aegypti (L.) and Aedes (Ochlerotatus) caspius (Pallas, 1771) in the capital city, Nouakchott. We describe the development sites in which larvae of the two species were found, drawing attention to the risk for emergence of arbovirus transmission in the city. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Asma Mahmoud Hamza
Full Text Available Anopheles arabiensis Patton (Diptera: Culicidae is considered the most efficient malaria vector in eastern Sudan. This study aims to characterize the breeding sites of An. arabiensis throughout the year in and around Kassala town, eastern Sudan. Diverse larval habitat types were visited and characterized based on the habitat type and chemical composition. Mosquito larvae were found in many diverse habitats. During the rainy season, rain pools and water bodies created by the seasonal Gash River serve as the main breeding sites. In the dry season, irrigation canals, seepage from water pipes, neglected wells, artificial containers, and man-made ditches serve as the main breeding sites. Breeding water showed a pH of 7.9 and a low concentration of the total dissolved salts. The results of this study may be considered in planning and implementing larval control programs in the area.
Full Text Available The introduction of the Asian tiger mosquito Aedes (Stegomya albopictus (Diptera: Culicidae into temperate regions poses serious concerns for the risk of the spreading of arboviral epidemics, as confirmed by the Chikungunya fever outbreak in Italy. This article describes the implementation and the results of a strategy for the pest management implemented over 4 years in Pesaro (a city in the Marche region, Italy. The strategy used 60 integrated wide‑sized ovitraps for monitoring purposes. Twenty-day larvicide-based treatment cycles were implemented for the manholes of the urban area and also the inhabitants were involved in pest control relating to their own properties. It was observed that the weekly median of eggs laid decreased consistently from 2008 to 2011, indicating the good performance of the vector control and a reduction in the related epidemics risk.
Full Text Available Spatial evaluation of Culicidae (Diptera larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers as larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.
Cleandson Ferreira SANTOS
Full Text Available In Brazil, most studies of the Culicidae family are concentrated in rainforest regions. As such, there is a lack of knowledge regarding the diversity of Culicidae in regions with different climatic and vegetational characteristics. The aim of this study was to compile an inventory of Culicidae in protected areas of the semi-arid region of the state of Minas Gerais, Brazil, in order to better understand the diversity of the family within this region. The study was conducted across four protected areas in the northern region of the state, in tropical dry forest (TDF fragments. Sampling methods included Shannon trap and CDC light trap, as well as active collection. A total of 11,219 mosquito specimens were collected between August 2008 and July 2012, belonging to 11 genera and 45 species; 15 new records for the state of Minas Gerais were registered, as well as 26 new records for semi-arid regions within the state. The high number of new Culicidae records in this region demonstrates the importance of inventory studies for increasing the knowledge of culicid biodiversity in Minas Gerais, and in particular within semi-arid regions of the state.
Santos, Cleandson Ferreira; Silva, Alex Chavier; Rodrigues, Raquel Andrade; de Jesus, Jamilli Sanndy Ramos; Borges, Magno Augusto Zazá
In Brazil, most studies of the Culicidae family are concentrated in rainforest regions. As such, there is a lack of knowledge regarding the diversity of Culicidae in regions with different climatic and vegetational characteristics. The aim of this study was to compile an inventory of Culicidae in protected areas of the semi-arid region of the state of Minas Gerais, Brazil, in order to better understand the diversity of the family within this region. The study was conducted across four protected areas in the northern region of the state, in tropical dry forest (TDF) fragments. Sampling methods included Shannon trap and CDC light trap, as well as active collection. A total of 11,219 mosquito specimens were collected between August 2008 and July 2012, belonging to 11 genera and 45 species; 15 new records for the state of Minas Gerais were registered, as well as 26 new records for semi-arid regions within the state. The high number of new Culicidae records in this region demonstrates the importance of inventory studies for increasing the knowledge of culicid biodiversity in Minas Gerais, and in particular within semi-arid regions of the state.
Cook, Shelley; Diallo, Mawlouth; Sall, Amadou A; Cooper, Alan; Holmes, Edward C
Correct classification of the insect vector is central to the study of arboviral disease. A simple molecular method for identification of the main vectors of the mosquito-borne viruses, dengue, yellow fever, and Rift Valley fever in Senegal, West Africa, was developed. We present a system in which the five mosquito species (Diptera: Culicidae) responsible for the majority of flaviviral disease transmission in Senegal can be reliably identified using small amounts of DNA coextracted during flaviviral screening procedures, via an easy amplification of the mitochondrial gene cytochrome oxidase c subunit I or II (COI or COII, respectively). We observed that despite very similar morphology, the two cryptic disease vector species Aedes furcifer Edwards and Aedes taylori Edwards are highly divergent at the molecular level. This sequence variation was used as a basis for the development of a polymerase chain reaction-restriction fragment-length polymorphism system for the differentiation of the two species. We also present the first investigation of the phylogeny of the culicine mosquitoes based on all COI and COII sequences currently available. There seems to be very low intraspecific variation in both genes, whereas interspecific variation is high. As a consequence, COI and COII are ideal candidates for the molecular identification of disease vectors to species level, whereas deeper divergences remain equivocal by using these genes. This system provides a new technique for the accurate identification of culicine disease vectors in West Africa and provides a basis for the expansion of such methods into the study of a range of diseases.
Thiemann, T C; Lemenager, D A; Kluh, S; Carroll, B D; Lothrop, H D; Reisen, W K
West Nile virus (family Flaviviridae, genus Flavivirus, WNV) is now endemic in California across a variety of ecological regions that support a wide diversity of potential avian and mammalian host species. Because different avian hosts have varying competence for WNV, determining the blood-feeding patterns of Culex (Diptera: Culicidae) vectors is a key component in understanding the maintenance and amplification of the virus as well as tangential transmission to humans and horses. We investigated the blood-feeding patterns of Culex tarsalis Coquillett and members of the Culex pipiens L. complex from southern to northern California. Nearly 100 different host species were identified from 1,487 bloodmeals, by using the mitochondrial gene cytochrome c oxidase I (COI). Cx. tarsalis fed on a higher diversity of hosts and more frequently on nonhuman mammals than did the Cx. pipiens complex. Several WNV-competent host species, including house finch and house sparrow, were common bloodmeal sources for both vector species across several biomes and could account for WNV maintenance and amplification in these areas. Highly competent American crow, western scrub-jay and yellow-billed magpie also were fed upon often when available and are likely important as amplifying hosts for WNV in some areas. Neither species fed frequently on humans (Cx. pipiens complex [0.4%], Cx. tarsalis [0.2%]), but with high abundance, both species could serve as both enzootic and bridge vectors for WNV.
Demirci, Berna; Durmaz, Esra; Alten, Bulent
Culex theileri Theobald (Diptera: Culicidae) has a wide Afrotropical, southern Palaearctic, northern Oriental, and European distribution. It is mainly considered as a mammophilic mosquito and also feeds on birds and serves as a vector for various zoonotic diseases including West Nile virus. Despite its broad distribution and evidence indicating that Cx. theileri is a competent vector of human and domestic animal pathogens, basic biological and ecological features of this species have not been well investigated. We evaluated the impact of bloodmeal source (human, chicken, cow, and a double bloodmeal such as human and cow or chicken and cow and mixed bloodmeals [cow, chicken, and human] via artificial feeding) on fecundity, hatching rates, developmental times, and viability from egg to adult for laboratory colonized Cx. theileri. Fecundity in mosquitoes that took a chicken bloodmeal, a double bloodmeal and mixed bloodmeals was significantly higher than in females fed on a single cow or single human blood. This is the first study about the bloodmeal sources effect on laboratory-reared Cx. theileri populations and these findings contribute to our understanding of the impact of bloodmeal source on reproduction in Cx. theileri. As it is known that Cx. theileri is a vector for West Nile virus, the potential impacts of bloodmeal source on virus transmission are discussed. © 2014 Entomological Society of America.
Garelli, F M; Espinosa, M O; Weinberg, D; Coto, H D; Gaspe, M S; Gürtler, R E
A citywide control program of Aedes aegypti (L.) (Diptera: Culicidae) mainly based on the use of larvicides reduced infestations but failed to achieve the desired target levels in Clorinda, northeastern Argentina, over 5 yr of interventions. To understand the underlying causes of persistent infestations and to develop new control tactics adapted to the local context, we conducted two pupal surveys in a large neighborhood with approximately 2,500 houses and recorded several variables for every container inspected in fall and spring 2007. In total, 4,076 lots and 4,267 containers were inspected over both surveys, and 8,391 Ae. aegypti pupae were collected. Large tanks used for potable water storage were the most abundant and the most productive type of container, accounting for 65-84% of all the pupae collected. Therefore, large tanks were key containers and candidates for improved targeted interventions. Multivariate analysis showed that containers located in the yard, at low sun exposure, unlidded, filled with rain water, and holding polluted water were all more likely to be infested by larvae or pupae. When only infested containers were considered, productivity of pupae was most closely associated with large tanks and rain water. A stochastic simulation model was developed to calculate the expected correlations between pupal and Stegomyia indices according to the characteristics of the distribution of larvae and pupae per container and the spatial scale at which the indices were computed. The correlation between pupal and Stegomyia indices is expected to increase as infestation levels decline.
Full Text Available Background: Dengue is amongst the most serious mosquito-borne infectious disease with hot spots in tropical and subtropical parts of the world. Unfortunately, no licensed vaccine for the disease is currently available in medicine markets. The only option available is the management of dengue vector mosquito, Aedes aegypti (Diptera: Culicidae.Method: Predatory potential of five odonate nymphs namely Anax parthenope, Bradinopyga geminate, Ischnura forcipata, Rhinocypha quadrimaculata, and Orthetrum sabina were evaluated against the 4th instar larvae of the dengue vector mosquito, Aedes aegypti, under laboratory conditions. The consumption of the mosquito larvae was evaluated at three water volume levels viz., 1 liter, 2 liter and 3 liter.Results: The number of Ae. aegypti larvae consumed varied significantly among the five species, and at different levels of water volume (P< 0.01. However, the interaction between odonate nymphs and the water volumes was statistically non-significant (P> 0.05. Ischnura forcipata consumed the highest number of Ae. aegypti larvae (n=56 followed by A. parthenope (n=47 and B. geminate (n=46. The number of larvae consumed was decreased with increasing search area or water volume, and the highest predation was observed at 1-liter water volume.Conclusion: The odonate nymphs could be a good source of biological agents for the management of the mosquitoes at larval stages.
Songsawatkiat, Siripan; Baimai, Visut; Thongsahuan, Sorawat; Otsuka, Yasushi; Taai, Kritsana; Hempolchom, Chayanit; Srisuka, Wichai; Poolphol, Petchaboon; Choochote, Wej; Saeung, Atiporn
Metaphase karyotype investigation on two allopatric strains of Anopheles nitidus Harrison, Scanlon, and Reid (Diptera: Culicidae) was conducted in Thailand during 2011-2012. Five karyotypic forms, i.e., Form A (X1, Y1), Form B (X1, Y2), Form C (X2, Y3), Form D (X1, X3, Y4), and Form E (X1, X2, X3, Y5) were obtained from a total of 21 isofemale lines. Forms A, B, and C were confined to Phang Nga Province, southern Thailand, whereas Forms D and E were restricted to Ubon Ratchathani Province, northeastern Thailand. Cross-mating experiments among the five isofemale lines, which were representative of five karyotypic forms of An. nitidus, revealed genetic compatibility by providing viable progenies and synaptic salivary gland polytene chromosomes through F2 generations. The results suggest that the forms are conspecific, and An. nitidus comprises five cytological races. The very low intraspecific sequence variations (average genetic distances = 0.002-0.008) of the nucleotide sequences in ribosomal DNA (internal transcribed spacer 2) and mitochondrial DNA (cytochrome c oxidase subunits I and II) among the five karyotypic forms were very good supportive evidence. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.
Bartlett-Healy, Kristen; Crans, Wayne; Gaugler, Randy
The blood meals of field-collected female Culex territans (Diptera: Culicidae) were concurrently assayed for the presence of trypanosomes and for vertebrate host identification. We amplified vertebrate DNA in 42 of 119 females and made positive identification to the host species level in 29 of those samples. Of the 119 field-collected Cx. territans females, 24 were infected with trypanosomes. Phylogenetic analysis placed the trypanosomes in the amphibian portion of the aquatic clade of the Trypanosomatidae. These trypanosomes were isolated from Cx. territans females that had fed on the frog species Rana clamitans, R. catesbeiana, R. virgatipes, and Rana spp. Results support a potential new lineage of dipteran-transmitted amphibian trypanosomes may occur within the aquatic clade. The frequency in which female Cx. territans acquire trypanosomes, through diverse feeding habits, indicates a new relationship between amphibian trypanosomes and mosquitoes that has not been examined previously. Combining Trypanosoma species, invertebrate, and vertebrate hosts to existing phylogenies can elucidate trypanosome and host relationships.
Cetin, H; Yanikoglu, A; Kocak, O; Cilek, J E
The larvicidal activity of chlorpyrifos-methyl and temephos was evaluated against Culex pipiens L. (Diptera: Culicidae) in septic tanks in Antalya, Turkey. Chlorpyrifos-methyl (Pyrifos MT 25 emulsifiable concentrate [EC] ) was evaluated at application rates of 0.04, 0.08, and 0.12 mg active ingredient (AI)/liter, and temephos (Temeguard 50 EC) was evaluated at 0.02, 0.04, and 0.06 mg (AI)/liter during a 21-d study. Generally, overall larval reduction in septic tanks from single- and multifamily dwellings treated with either larvicide was significantly greater than pretreatment levels and control tanks for the duration of the study. At 14 d posttreatment, duration of control was greatest in multifamily tanks treated with chlorpyrifos-methyl at the highest application rate with similar levels of control through 21 d for single-family dwellings (range 97-100%). Septic tanks from both types of family dwellings treated at the highest application rate of temephos resulted in >90% reduction through day 21 (range 91-100%). Laboratory bioassays of septic tank water treated at field application rates, without daily dilution, revealed that complete larval mortality was achieved for 21 d at each application rate and formulation. It is thought that daily addition of water and organic matter to the septic tanks in the single and multifamily dwellings influenced the duration of effectiveness of the larvicides.
María L. PESCHIUTTA
Full Text Available Aedes aegypti (Linnaeus (Diptera: Culicidae es vector de los agentes etiológicos de la fiebre amarilla y del dengue. Una alternativa al control químico de este vector es el uso de agentes biológicos. Los nematodos entomopatógenos son efectivos en el control de plagas. La infectividad y el ciclo de vida de un aislado argentino de Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae en larvas de A. aegypti se registró por primera vez bajo condiciones de laborato - rio. Para cada unidad experimental, 30 larvas de mosquito de segundo estadio fueron expuestas a 8 dosis del nematodo (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1. Los juveniles infectivos (JIs utilizados fueron multiplicados sobre Galleria mellonella (Lepidoptera: Pyralidae. La continuidad infectiva de los JIs obtenidos de A. aegypti fue probada aplicándolos en una dosis de 100:1 sobre larvas del mosquito . Las tasas de mortalidad fueron de 0% a 84%. El número de nematodos desarrollados dentro de la larva de mosquito, la mortalidad larval y los nuevos JIs se incrementaron con el aumento de la dosis de nematodos. Los resultados indican que H. bacteriophora es capaz de infectar larvas de A. aegypti , se desarrolla y produce nuevos JIs, permitiendo la continuidad de su ciclo de vida.
Clarice Noleto Dias
Full Text Available The mosquito Aedes aegypti L. (Diptera: Culicidae is the major vector of dengue and chikungunya fever. The lack of effective therapies and vaccines for these diseases highlights the need for alternative strategies to control the spread of virus. Therefore, this study investigated the larvicidal potential of essential oils from common plant species obtained from the Chapada das Mesas National Park, Brazil, against third instar A. aegypti larvae. The chemical composition of these oils was determined by gas chromatography coupled to mass spectrometry. The essential oils of Eugenia piauhiensis Vellaff., Myrcia erythroxylon O. Berg, Psidium myrsinites DC., and Siparuna camporum (Tul. A. DC. were observed to be mainly composed of sesquiterpene hydrocarbons. The essential oil of Lippia gracilis Schauer was composed of oxygenated monoterpenes. Four of the five tested oils were effective against the A. aegypti larvae, with the lethal concentration (LC50 ranging from 230 to 292 mg/L after 24 h of exposure. Overall, this work demonstrated the possibility of developing larvicidal products against A. aegypti by using essential oils from the flora of the Brazilian Legal Amazon. This in turn demonstrates the potential of using natural resources for the control of disease vectors.
Lang, Bethan J; Idugboe, Stefano; McManus, Kirelle; Drury, Florence; Qureshi, Alima; Cator, Lauren J
Control of Aedes aegypti (L.) (Diptera: Culicidae) populations is vital for reducing the transmission of several pervasive human diseases. The success of new vector control technologies will be influenced by the fitness of laboratory-reared transgenic males. However, there has been relatively little published data on how rearing practices influence male fitness in Aedes mosquitoes. In the laboratory, the effect of larval food availability on adult male fitness was tested, using a range of different fitness measures. Larval food availability was demonstrated to be positively correlated with adult body size. Larger males survived longer and exhibited greater swarming activity. As a consequence, larger males may have more mating opportunities in the wild. However, we also found that within a swarm larger males did not have an increased likelihood of copulating with a female. The outcome of the mating competition experiments depended on the methodology used to mark the males. These results show that fitness assessment can vary depending on the measure analyzed, and the methodology used to determine it. Continued investigation into these fitness measures and methodologies, and critically, their utility for predicting male performance in the field, will increase the efficiency of vector control programs. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.
Sarkar, Manas; Akulwad, Ambadas; Kshirsagar, Rajendra; Muthukrishnan, Siva
Intensive exposure to insecticides has resulted in the evolution of insecticide resistance in the mosquitoes. We tested the bio-efficacy of two Culex quinquefasciatus Say (Diptera: Culicidae) laboratory strains differentially bio-responsive to pyrethroids to understand the comparative efficacy of different polyfluorobenzyle and conventional pyrethroid molecules and the role of piperonyl butoxide (PBO) in synergizing these molecules in increased tolerance of mosquitoes to these molecules. We have taken deltamethrin (α-cyano pyrethroid with phenoxybenzyl moiety); permethrin (phenoxybenzyl pyrethroid without an α-cyano group); transfluthrin, dimefluthrin, metofluthrin, and meperfluthrin (polyfluorinated benzyl compounds); and prallethrin (modified cyclopentadienone compound) for this study. We found higher bio-efficacy in dimefluthrin, metofluthrin, and meperfluthrin compared with transfluthrin against tested mosquito strains. We found that transfluthrin exhibited synergism with PBO, which supports the hypothesis that P450 enzymes could play a role in the detoxification process of transfluthrin, which was earlier not believed. However, other polyfluorobenzyl pyrethroids with a 4-(methoxymethyl) phenyl capping in the tetrafluorobenzyl ring (dimefluthrin, metofluthrin, and meperfluthrin) exhibit greater synergism with PBO compared with transfluthrin. Further study is required to understand the mechanism for higher synergistic ratios in polyfluorobenzyl pyrethroids with 4-(methoxymethyl) phenyl moiety and ascertain the possible involvement of novel mechanisms that may involve in developing resistance. This is the first report of comparative bio-efficacy of multiple polyfluorobenzyl pyrethroids and PBO synergism against mosquitoes.
geografica actualizada. Rev. Inv. Salud Publica (Mexico) 33: 11 I - 125. Heinemann, S.J. and J.N. Belkin. 1977. Collection records of the project...Mosquitoes of Middle America” 8. Central America: Belize (BH), Guatemala (GUA), El Salvador ( SAL ), Honduras (HON), Nicaragua (NI, NIC). Mosq. Syst...Culicidae). Ill. Nat. Hist. Surv. Biol. Notes 52, 50 pp. Vargas, L. 1956. Especies y distribucidn de mosquitos mexicanos no anofelinos. Rev. Instit. de
Zittra, Carina; Obwaller, Adelheid G; Wimmer, Victoria; Berer, Dominik; Eigner, Barbara; Fuehrer, Hans-Peter
During a three-year mosquito monitoring from 2014 to 2016, the strictly ornithophilic, originally Mediterranean species Orthopodomyia pulcripalpis (Rondani, 1872) was collected as single specimen for the first time in Austria in the district of Penzing in Vienna. Morphological species determination was confirmed by analysis of the mitochondrial cytochrome c oxidase subunit I gene. We thus not only confirm the existence of another mosquito species in Austria, but also add a new genus to the Austrian Culicidae taxa list.
Transcriptional Analysis of Four Family 4 P450s in a Puerto Rico Strain of Aedes aegypti (Diptera: Culicidae) Compared With an Orlando Strain and Their Possible Functional Roles in Permethrin Resistance
MOLECULAR BIOLOGY/GENOMICS Transcriptional Analysis of Four Family 4 P450s in a Puerto Rico Strain of Aedes aegypti (Diptera: Culicidae) Compared...10.1603/ME13228 ABSTRACT A Þeld strain of Aedes aegypti (L.) was collected from Puerto Rico in October 2008. Based onLD50 values by topical application...important role in cytochrome P450-mediated resistance to permethrin. KEY WORDS Aedes aegytpi, permethrin, resistance, cytochrome P450, detoxiÞcation The
Full Text Available Aedes albopictus (Skuse, 1884 (Diptera: Culicidae, a mosquito native to Asia, has recently invaded all five continents. In Central Africa it was first reported in the early 2000s, and has since been implicated in the emergence of arboviruses such as dengue and chikungunya in this region. Recent genetic studies of invasive species have shown that multiple introductions are a key factor for successful expansion in new areas. As a result, phenotypic characters such as vector competence and insecticide susceptibility may vary within invasive pest species, potentially affecting vector efficiency and pest management. Here we assessed the genetic variability and population genetics of Ae. albopictus isolates in Cameroon (Central Africa, thereby deducing their likely geographic origin.Mosquitoes were sampled in 2007 in 12 localities in southern Cameroon and analyzed for polymorphism at six microsatellite loci and in two mitochondrial DNA regions (ND5 and COI. All the microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structureamong geographic populations (F(ST = 0.068, P < 0.0001. Analysis of mtDNA sequences revealed four haplotypes each for the COI and ND5 genes, with a dominant haplotype shared by all Cameroonian samples. The weak genetic variation estimated from the mtDNA genes is consistent with the recent arrival of Ae. albopictus in Cameroon. Phylogeographic analysis based on COI polymorphism indicated that Ae. albopictus populations from Cameroon are related to tropical rather than temperate or subtropical outgroups.The moderate genetic diversity observed among Cameroonian Ae. albopictus isolates is in keeping with recent introduction and spread in this country. The genetic structure of natural populations points to multiple introductions from tropical regions.
Fahd A. Al-Mekhlafi
Full Text Available Effects of methanol extracts of Xanthium strumarium on different cancer cell lines and on the mortality rates of Aedes caspius, Culex pipiens (Diptera: Culicidae were investigated. Among the cell lines tested, the Jurkat cell line was the most sensitive to the methanol extract and ethyl acetate fraction, with reported LC50 values of 50.18 and 48.73 μg/ml respectively. Conversely, methanol extracts were not that toxic to the A549 cell line though the toxicity increased on further purification. The percentage of growth inhibition was dose dependent for the methanol extract and ethyl acetate fraction. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The results showed that methanol extracts of plant seeds caused 100% mortality of mosquito larvae at a concentration of 1000 μg/ml after 24 h of treatment. The LC50 and LC90 values of X. strumarium were found to be 531.07 and 905.95 μg/ml against Ae. caspius and 502.32 and 867.63 μg/ml against Cx. Pipiens, respectively. From the investigations, it was concluded that the crude extract of X. strumarium showed a weak potential for controlling the larval instars of Ae. caspius and Cx. pipiens. However, on further purification the extract lost the larvicidal activity. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The ethyl acetate fraction investigated in this study appears to have a weak larvicidal activity but a promising cytotoxic activity. Future studies will include purification and investigation in further detail of the action of X. strumarium on Cancer Cell Lines and mosquitoes.
Al-Mekhlafi, Fahd A; Abutaha, Nael; Mashaly, Ashraf M A; Nasr, Fahd A; Ibrahim, Khalid E; Wadaan, Mohamed A
Effects of methanol extracts of Xanthium strumarium on different cancer cell lines and on the mortality rates of Aedes caspius, Culex pipiens (Diptera: Culicidae) were investigated. Among the cell lines tested, the Jurkat cell line was the most sensitive to the methanol extract and ethyl acetate fraction, with reported LC 50 values of 50.18 and 48.73 μg/ml respectively. Conversely, methanol extracts were not that toxic to the A549 cell line though the toxicity increased on further purification. The percentage of growth inhibition was dose dependent for the methanol extract and ethyl acetate fraction. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The results showed that methanol extracts of plant seeds caused 100% mortality of mosquito larvae at a concentration of 1000 μg/ml after 24 h of treatment. The LC 50 and LC 90 values of X. strumarium were found to be 531.07 and 905.95 μg/ml against Ae. caspius and 502.32 and 867.63 μg/ml against Cx. Pipiens, respectively. From the investigations, it was concluded that the crude extract of X. strumarium showed a weak potential for controlling the larval instars of Ae. caspius and Cx. pipiens . However, on further purification the extract lost the larvicidal activity. The ethyl acetate fraction showed higher toxicity to all cell lines tested when compared to the methanol extract. The ethyl acetate fraction investigated in this study appears to have a weak larvicidal activity but a promising cytotoxic activity. Future studies will include purification and investigation in further detail of the action of X. strumarium on Cancer Cell Lines and mosquitoes.
QIU, YU TONG; SMALLEGANGE, RENATE C.; TER BRAAK, CAJO J. F.; SPITZEN, JEROEN; VAN LOON, JOOP J. A.; JAWARA, MUSA; MILLIGAN, PAUL; GALIMARD, AGNES M.; VAN BEEK, TERIS A.; KNOLS, BART G. J.; TAKKEN, WILLEM
Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to which carbon dioxide (CO2) was added were tested in four sets of experiments. In a second series of experiments, MM-X traps with 14 odor blends without CO2 were tested. A blend of ammonia and l-lactic acid with or without CO2 was used as control odor in series 1 and 2, respectively. Centers for Disease Control and Prevention (CDC) traps were placed in a traditional house and an experimental house to monitor mosquito densities during the experiments. The MM-X traps caught a total number of 196,756 mosquitoes, with the most abundant species belonging to the genera Mansonia (70.6%), Anopheles (17.5%), and Culex (11.5%). The most abundant mosquito species caught by the CDC traps (56,290 in total) belonged to the genera Mansonia (59.4%), Anopheles (16.0% An. gambiae s.l. Giles, and 11.3% An. ziemanni Grünberg), and Culex (11.6%). MM-X traps baited with synthetic blends were in many cases more attractive than MM-X traps baited with human odors. Addition of CO2 to synthetic odors substantially increased the catch of all mosquito species in the MM-X traps. A blend of ammonia + L-lactic acid + CO2 + 3-methylbutanoic acid was the most attractive odor for most mosquito species. The candidate odor blend shows the potential to enhance trap collections so that traps will provide better surveillance and possible control. PMID:18047195
Full Text Available Background & objectives: In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal and ovicidal potential of the crude hexane, benzene, chloroform, ethyl acetate and methanol solvent extracts from the medicinal plant Pithecellobium dulce against the mosquito vectors, Anopheles stephensi and Aedes aegypti (Diptera: Culicidae. Methods: Larvicidal activity of P. dulce plant extracts was studied in the range of 60 to 450 mg/l against early third instar larvae of An. stephensi and Ae. aegypti in the laboratory. The larval mortality was observed after 24 h of exposure. The ovicidal activity was determined against An. stephensi and Ae. aegypti to various concentrations ranging from 100 to 750 mg/l under the laboratory conditions. Mean per cent hatchability of the eggs were observed after 48 h post treatment. Results: All leaf and seed extracts showed moderate larvicidal and ovicidal effects; however, the highest larval mortality was found in methanol extract of leaf of P. dulce against the larvae of An. stephensi and Ae. aegypti with the LC 50 and LC 90 values 145.43, 155.78 mg/l and 251.23, 279.73 mg/l, respectively. The per cent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. Zero hatchability was observed at 400 mg/l for leaf methanol extract and 625 mg/l for seed methanol extract of P. dulce against An. stephensi and Ae. aegypti, respectively. Compared to leaf extracts, seed extracts have low potency against the two mosquitoes. Interpretation & conclusions: The present results suggest that the leaf and seed extracts of P. dulce have the potential to be used as an ideal eco-friendly approach for the control of mosquitoes.
Govindarajan, M; Rajeswary, M; Sivakumar, R
In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal and ovicidal potential of the crude hexane, benzene, chloroform, ethyl acetate and methanol solvent extracts from the medicinal plant Pithecellobium dulce against the mosquito vectors, Anopheles stephensi and Aedes aegypti (Diptera: Culicidae). Larvicidal activity of P. dulce plant extracts was studied in the range of 60 to 450 mg/l against early third instar larvae of An. stephensi and Ae. aegypti in the laboratory. The larval mortality was observed after 24 h of exposure. The ovicidal activity was determined against An. stephensi and Ae. aegypti to various concentrations ranging from 100 to 750 mg/l under the laboratory conditions. Mean per cent hatchability of the eggs were observed after 48 h post treatment. All leaf and seed extracts showed moderate larvicidal and ovicidal effects; however, the highest larval mortality was found in methanol extract of leaf of P. dulce against the larvae of An. stephensi and Ae. aegypti with the LC₅₀ and LC₉₀ values 145.43, 155.78 mg/l and 251.23, 279.73 mg/l, respectively. The per cent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. Zero hatchability was observed at 400 mg/l for leaf methanol extract and 625 mg/l for seed methanol extract of P. dulce against An. stephensi and Ae. aegypti, respectively. Compared to leaf extracts, seed extracts have low potency against the two mosquitoes. The present results suggest that the leaf and seed extracts of P. dulce have the potential to be used as an ideal eco-friendly approach for the control of mosquitoes.
Bernués Bañeres, Alberto
La familia Culicidae incluye algunas de las especies de dípteros más relevantes en el ámbito de la Salud Pública, no solo por las molestias que son capaces de causar debido a su tipo de alimentación hematófaga, sino por su capacidad para actuar como vectores de enfermedades de afección humana. Por este motivo, los mosquitos han sido, desde siempre, una de las dianas predilectas en los programas de control establecidos para la regulación de sus poblaciones y, por tanto, como medida profiláctic...
Almério de Castro Gomes
Full Text Available A Adultrap é uma nova armadilha feita para capturar fêmeas de Aedes aegypti. Foram realizados testes para avaliar sua especificidade tendo como referência a técnica da aspiração da espécie em abrigos artificiais. A Adultrap ficou exposta por 24 horas no intradomicílio e peridomicílio de 120 casas sorteadas em dois bairros da Cidade de Foz do Iguaçu, Estado do Paraná. O teste estatístico foi o modelo log-linear de Poisson. O resultado foi a captura de 726 mosquitos Culicidae, dos quais 80 eram Aedes aegypti. A Adultrap capturou apenas fêmeas desta espécie, enquanto o aspirador os dois sexos de Aedes aegypti e mais cinco outras espécies. A Adultrap capturou Aedes aegypti dentro e fora das casas, mas a análise indicou que no peridomicílio a armadilha capturou significantemente mais fêmeas do que a aspiração. Também, ficou evidenciada a sensibilidade da Adultrap para detectar Aedes aegypti em situação de baixa freqüência.The Adultrap is a new trap built for capturing females of Aedes aegypti. Tests were carried out to evaluate the specificity of this trap in comparison with the technique of aspiration of specimens in artificial shelters. Adultraps were kept for 24 hours inside and outside 120 randomly selected homes in two districts of the city of Foz do Iguaçú, State of Paraná. The statistical test was Poisson’s log-linear model. The result was 726 mosquitoes captured, of which 80 were Aedes aegypti. The Adultrap captured only females of this species, while the aspiration method captured both sexes of Aedes aegypti and another five species. The Adultrap captured Aedes aegypti inside and outside the homes, but the analysis indicated that, outside the homes, this trap captured significantly more females than aspiration did. The sensitivity of the Adultrap for detecting females of Aedes aegypti in low-frequency situations was also demonstrated.
Full Text Available OBJETIVO: Observar detalhes morfológicos de ovos de Haemagogus leucocelaenus visualizados pela primeira vez por microscopia eletrônica de varredura (MEV e realizar morfometria das principais estruturas. MÉTODOS: Foram utilizados ovos de Hg. leucocelaenus provenientes de fêmeas capturadas na Reserva Biológica do Tinguá, RJ, sendo parte destinada à eclosão e outra ao processamento de MEV, dos quais três foram submetidos à análise morfométrica. O material foi fixado em glutaraldeído 2,5% e pós-fixado em tetróxido de ósmio 1%, ambos em tampão cacodilato de sódio 0.1M, pH 7.2, processado e observado ao MEV Jeol 5310. Medições foram realizadas com o auxílio do software de análise Semafore. RESULTADOS: Os ovos apresentaram contorno elíptico com aproximadamente 574 µm de comprimento e 169 µm de largura, sendo o índice do ovo (l/wratio 3,39 µm. O exocório é extremamente regular, possuindo ornamentação hexagonal e algumas vezes pentagonal. Nas células coriônicas, observaram-se tubérculos simetricamente dispostos com relação ao eixo longitudinal, e, no interior delas, tubérculos menores, individualizados, dispostos na periferia, e poucos agrupados no centro. A superfície do retículo coriônico não apresentou rugosidades. O aparelho micropilar apresenta colar proeminente, contínuo, com disco micropilar bem evidente. CONCLUSÕES: A ornamentação do exocório apresenta diferenças em relação aos tubérculos das células coriônicas e ao retículo coriônico externo entre os ovos de Hg. leucocelaenus comparados aos ovos de Hg. janthinomys e Hg. equinus, bem como com relação aos de Aedes aegypti, Ae. albopictus e Ae bahamensis.OBJECTIVE: To observe morphological details of the eggs of Haemagogus (Conopostegus leucocelaenus, seen for the first time via scanning electron microscopy (SEM, with morphometric analysis of the main structures. METHODS: Eggs of Hg. leucocelaenus were obtained from females captured in the
Anthony Érico Guimarães
Full Text Available The ecology of anopheline species (Diptera, Culicidae was studied in the vicinity of the Serra da Mesa Reservoir, State of Goiás, Brazil. Climatic factors and frequency of anopheline populations were analyzed. Bimonthly human-bait and Shannon trap captures were conducted for 36 consecutive months (January 1997 through December 1999. A total of 5,205 adult anophelines belonging to five species were collected. Anopheles darlingi was the most frequently collected anopheline (61.4%, followed by An. albitarsis s.l. (35.4%, An. triannulatus. (2.5%, An. oswaldoi (0.4%, and An. evansae (0.2%. The water level and vegetation along the banks of the reservoir were crucial to the frequency of the various anopheline species. Climatic factors had a secondary influence. The reservoir's water-level stability, increased frequency of An. darlingi, and the arrival of gold prospectors were responsible for the increase in malaria cases.
Fouad El-Akhal; Abdelhakim El Ouali Lalami; Yassine Ez Zoubi; Hassane Greche; Raja Guemmouh
Objective:To evaluate the larvicidal activity of essential oil of Origanum majorana (Lamiaceae) cultivated in Morocco against Culex pipiens (Diptera:Culicidae). Methods: The analysis and the identification of the various constituents of essential oil were carried out by gas chromatography coupled with mass spectrometry. Biological test was performed according to a standard methodology inspired by the World Health Organization protocol with slight modification. Results:This oil mainly consisted of monoterpene and sesquiterpenes. The majority compounds are 4-terpinene (28.96%), γ-terpinene (18.57%), α-terpinene (12.72%) and sabinene (8.02%). The lethal concentrations (LC50 and LC90) measured for the essential oil Origanum majorana, were respectively of the order of 258.71 mg/L and 580.49 mg/L.
Saavedra, Laura M; Romanelli, Gustavo P; Rozo, Ciro E; Duchowicz, Pablo R
The insecticidal activity of a series of 62 plant derived molecules against the chikungunya, dengue and zika vector, the Aedes aegypti (Diptera:Culicidae) mosquito, is subjected to a Quantitative Structure-Activity Relationships (QSAR) analysis. The Replacement Method (RM) variable subset selection technique based on Multivariable Linear Regression (MLR) proves to be successful for exploring 4885 molecular descriptors calculated with Dragon 6. The predictive capability of the obtained models is confirmed through an external test set of compounds, Leave-One-Out (LOO) cross-validation and Y-Randomization. The present study constitutes a first necessary computational step for designing less toxic insecticides. Copyright © 2017 Elsevier B.V. All rights reserved.
Liu, Yan-Xia; Li, Fen-Xiang; Liu, Zhuan-Zhuan; Jia, Zhi-Rong; Zhou, Yan-He; Zhang, Hao; Yan, Hui; Zhou, Xian-Qiang; Chen, Xiao-Guang
Mosquito microRNAs (miRNAs) are involved in host-virus interaction, and have been reported to be altered by dengue virus (DENV) infection in Aedes albopictus (Diptera: Culicidae). However, little is known about the molecular mechanisms of Aedes albopictus midgut-the first organ to interact with DENV-involved in its resistance to DENV. Here we used high-throughput sequencing to characterize miRNA and messenger RNA (mRNA) expression patterns in Aedes albopictus midgut in response to dengue virus serotype 2. A total of three miRNAs and 777 mRNAs were identified to be differentially expressed upon DENV infection. For the mRNAs, we identified 198 immune-related genes and 31 of them were differentially expressed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses also showed that the differentially expressed immune-related genes were involved in immune response. Then the differential expression patterns of six immune-related genes and three miRNAs were confirmed by real-time reverse transcription polymerase chain reaction. Furthermore, seven known miRNA-mRNA interaction pairs were identified by aligning our two datasets. These analyses of miRNA and mRNA transcriptomes provide valuable information for uncovering the DENV response genes and provide a basis for future study of the resistance mechanisms in Aedes albopictus midgut. © 2016 Institute of Zoology, Chinese Academy of Sciences.
Collao, Ximena; Prado, Lorena; González, Christian; Vásquez, Ana; Araki, Romina; Henríquez, Tuki; Peña, Cindy M
Flaviviruses are arthropod-borne viruses, mainly by mosquitoes of the genera Aedes and Culex (Culicidae) that are detected in tropical and subtropical areas. Main flaviviruses of public health importance are: dengue, West Nile virus, yellow fever, among others. In continental Chile, flaviviruses has not been detected. However, there are indigenous cases of dengue detected in Easter Island since 2002, as the presence of its vector Aedes aegypti. The aim of this study was: To determine diversity of flavivirus mosquitoes present in Easter Island. Thirty pools of mosquitoes collected in Hanga Roa were analyzed; a RT-PCR nested flavivirus was performed. Thirteen positive samples were detected and the amplification products were sequenced, identifying two specific flavivirus Insect, the Cell fusing agent virus and other related viruses Kamiti River. This is the first study in Chile showed the presence of flavivirus in vectors in Easter Island.
A list of mosquito species of the Brazilian State of Pernambuco, including the first report of Haemagogus janthinomys (Diptera: Culicidae, yellow fever vector and 14 other species (Diptera: Culicidae Lista de espécies de mosquitos do Estado de Pernambuco e primeiro relato de Haemagogus janthinomys (Diptera: Culicidae vetor de febre amarela silvestre e outras 14 espécies (Diptera: Culicidae
Nádia Consuelo Aragão
Full Text Available INTRODUCTION: Besides mosquito species adapted to urban environments (Culex quinquefasciatus, Aedes aegypti and Aedes albopictus, only 15 species of Anopheles had been recorded in the State of Pernambuco. METHODS: Human-landing mosquitoes were collected in Dois Irmãos Park, in Recife. RESULTS: The first report for the state of Haemagogus janthinomys, an important vector of yellow fever virus, and 14 other species, including Trichoprosopon lampropus, a first reported for Brazil. CONCLUSIONS: The mosquito fauna in the area is diversified and has potential medical and veterinary importance.INTRODUÇÃO: Além de mosquitos adaptados ao ambiente urbano (Culex quinquefasciatus, Aedes aegypti e Ae. albopictus, apenas 15 espécies de Anopheles haviam sido relatadas no Estado de Pernambuco. MÉTODOS: Mosquitos que pousavam em humanos no Parque Dois Irmãos, em Recife foram coletados. RESULTADOS: Haemagogus janthinomys, importante vetor de vírus de febre amarela, e outras 14 espécies são relatadas pela primeira vez no estado, incluindo Trichoprosopon lampropus, relatado pela primeira vez no Brasil. CONCLUSÕES: A fauna de mosquitos na área é muito diversificada e tem potencial importância médica e veterinária.
Myriam Janeth Salazar
Full Text Available El objetivo de este trabajo fue estudiar varios aspectos del crecimiento y el desarrollo de los estadios inmaduros de Culex quinquefasciatus Say, 1826 (Diptera: Culicidae, especie antropofílica frecuentemente encontrada en Bogotá. Con este fin, se realizaron dos experimentos en diferentes épocas del año 2001 (enero-febrero y septiembre-octubre, bajo condiciones no controladas (luz, temperatura y humedad relativa. Se colocaron recipientes plásticos transparentes con agua de charca a la que se le adicionó concentrado para perro; se tomaron cuatro balsas al azar para estudiar el ciclo de vida utilizando los parámetros de la tabla de vida: mortalidad y supervivencia. Las hembras ovipositaron entre cinco y ocho días después de la ingestión de sangre. El número de huevos por balsa varió entre 152 y 203. La eclosión de larvas L1 fue de 50% en el primer experimento y de 75% en el segundo. Se destacó la naturaleza no sincrónica de la eclosión de las L1, la menor duración proporcional del estadio de pupa (11% del tiempo del desarrollo total y la eficiencia del cambio pupa-adulto (98,61%. Se reporta una menor duración del ciclo de lo informado previamente. Además, los altos porcentajes de eclosión (83,58%, pupación (86,63% y emergencia (98,61% con las condiciones presentes para estos experimentos (temperatura media 14,8°C y 15,1°C y humedad relativa del 72,5% y 74,1%, respectivamente indican el alto grado de adaptación de C. quinquefasciatus al ambiente bogotano. Estas características, más la capacidad vectorial y la resistencia a los insecticidas, hacen de esta especie un problema de salud pública.
Zhang, L.; Tang, B.; Huang, E.; Huang, Z.; Liu, Z.; Huang, T.; Gelbič, Ivan; Guan, X.; Xu, L.
Roč. 106, č. 3 (2013), s. 1098-1102 ISSN 0022-0493 Grant - others:National Natural Science Foundation of China(CN) 31071745; National Natural Science Foundation of China(CN) 31201574; Ministry of Education of China(CN) 20093515110010; Ministry of Education of China(CN) 20093515120010; Agricultural Science and Technology Achievements(CN) 2010GB2C400212; National High Technology Research and Development Program 863(CN) 2011AA10A203; Universities of Fujian Province(CN) JA12092; Fujian Agriculture and Forestry University(CN) xjq201203; Universities for the Development of the West Strait(CN) 0b08b005 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis * receptor binding * ELISA Subject RIV: ED - Physiology Impact factor: 1.605, year: 2013 http://www.bioone.org/doi/pdf/10.1603/EC12308
Spatial evaluation of larvae of Culicidae (Diptera from different breeding sites: application of a geospatial method and implications for vector control Avaliação espacial de formas larvais de Culicidae (Diptera em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores
Full Text Available Spatial evaluation of Culicidae (Diptera larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers as larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.Avaliação espacial de formas larvais de Culicidae (Diptera em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores. Este estudo investiga a distribuição espacial da fauna urbana e de Culicidae e informa o monitoramento entomológico de espécies que usam recipientes artificiais como habitat larval. Coletas de larvas de mosquitos foram realizadas no município paulista de Santa Bárbara d' Oeste entre os anos de 2004 e 2006, durante visitas casa-a-casa. Um total de 1.891 amostras foi considerado, com nove espécies diferentes coletadas. A distribuição das espécies foi avaliada através do método de krigagem estatística extrapolando as divisões administrativas do município. O método de coleta adotado no presente estudo está de acordo com os métodos sugeridos aos serviços de saúde municipais pelo Ministério da Saúde e pode, portanto, ser adotado pelas autoridades p
Full Text Available Background: Bromeliads can be epiphytic, terrestrial or saxicolous and use strategies to allow water to be retained in their leaf axils, where various arthropods can be found. These include mosquitoes, whose larvae are the most abundant and commonly found organisms in the leaf axils. The objective of this study was to look for immature forms of mosquitoes (the larval and pupal stages in bromeliads in municipal parks in São Paulo and to discuss the ecological and epidemiological importance of these insects.Methods: From October 2010 to July 2013, immature mosquitoes were collected from bromeliads in 65 municipal parks in the city of São Paulo, Brazil, using suction samplers. The immature forms were maintained until adult forms emerged, and these were then identified morphologically.Results: Two thousand forty-two immature-stage specimens belonging to the genera Aedes, Culex, Trichoprosopon, Toxorhynchites, Limatus and Wyeomyia were found in bromeliads in 15 of the 65 parks visited. Aedes albopictus was the most abundant species (660 specimens collected, followed by Culex quinquefasciatus (548 specimens and Cx. (Microculex imitator (444. The taxa with the most widespread distribution were Ae. aegypti and Toxorhynchites spp, followed by Ae. albopictus and Cx. quinquefasciatus.Conclusion: Bromeliads in urban parks are refuges for populations of native species of Culicidae and breeding sites for exotic species that are generally of epidemiological interest. Hence, administrators and surveillance and mosquito-control agencies must constantly monitor these microenvironments as the presence of these species endangers the health of park users and employees as well as people living near the parks.
Full Text Available In 2014, Guangzhou City, South China, suffered from its worst outbreak of dengue fever in decades. Larval mosquito habitat surveillance was carried out by using android mobile devices in four study sites in May 2015. The habitats with larval mosquitoes were recorded as photo waypoints in OruxMaps or in videos. The total number of potential mosquito habitats was 342, of which 166 (49% were found to have mosquito larvae or pupae. Small containers were the most abundant potential habitats, accounting for 26% of the total number. More mosquito larvae and pupae, were found in small containers than in other objects holding water, for example, potted or hydroponic plants (p < 0.05. Mosquito larvae were collected from all plastic road barriers, used tires, and underground water. Aedes albopictus larvae were found from small and large containers, stumps, among others. The overall route index (RI was 11.3, which was 14.2 times higher than the grade C criteria of the National Patriotic Health Campaign Committee (NPHCC, China. The higher RIs were found from the bird and flower markets, schools, and underground parking lots. The results indicated that Android mobile devices are a convenient and useful tool for surveillance of mosquito habitats, and the enhancement of source reduction may benefit the prevention and control of dengue vector mosquitoes.
Chaves, Luis Fernando
It has been suggested that climate change may have facilitated the global expansion of invasive disease vectors, since several species have expanded their range as temperatures have warmed. Here, we present results from observations on two major global invasive mosquito vectors (Diptera: Culicidae), Aedes albopictus (Skuse) and Aedes japonicus (Theobald), across the altitudinal range of Mt. Konpira, Nagasaki, Japan, a location within their native range, where Aedes flavopictus Yamada, formerly a rare species, has now become dominant. Spatial abundance patterns of the three species suggest that temperature is an important factor influencing their adult distribution across the altitudinal range of Mt. Konpira. Temporal abundance patterns, by contrast, were associated with rainfall and showed signals of density-dependent regulation in the three species. The spatial and temporal analysis of abundance patterns showed that Ae. flavopictus and Ae. albopictus were negatively associated, even when accounting for differential impacts of weather and other environmental factors in their co-occurrence patterns. Our results highlight a contingency in the expansion of invasive vectors, the potential emergence of changes in their interactions with species in their native communities, and raise the question of whether these changes might be useful to predict the emergence of future invasive vectors.
Full Text Available Salivary gland proteins of the human malaria vector, Anopheles dirus B were determined and analyzed. The amount of salivary gland proteins in mosquitoes aged between 3 - 10 days was approximately 1.08 ± 0.04 µg/female and 0.1 ± 0.05 µg/male. The salivary glands of both sexes displayed the same morphological organization as that of other anopheline mosquitoes. In females, apyrase accumulated in the distal regions, whereas alpha-glucosidase was found in the proximal region of the lateral lobes. This differential distribution of the analyzed enzymes reflects specialization of different regions for sugar and blood feeding. SDS-PAGE analysis revealed that at least seven major proteins were found in the female salivary glands, of which each morphological region contained different major proteins. Similar electrophoretic protein profiles were detected comparing unfed and blood-fed mosquitoes, suggesting that there is no specific protein induced by blood. Two-dimensional polyacrylamide gel analysis showed the most abundant salivary gland protein, with a molecular mass of approximately 35 kilodaltons and an isoelectric point of approximately 4.0. These results provide basic information that would lead to further study on the role of salivary proteins of An. dirus B in disease transmission and hematophagy.Proteínas das glândulas salivares do Anopheles dirus B (Diptera: Culicidae, vetor da malária humana foram determinadas e analisadas. A quantidade de proteínas das glândulas salivares em mosquitos com três a 10 dias de idade foi de aproximadamente 1,08 ± 0,04 µg/ fêmea e de 0,1 ± 0,05 µg/macho. As glândulas salivares de ambos os sexos mostraram organização morfológica semelhante à de outros mosquitos anofelinos. Em fêmeas, apirase acumula-se nas regiões distais, enquanto alfa-glucosidase foi encontrada na região proximal dos lóbulos laterais. Esta distribuição diferencial das enzimas analisadas reflete a especialização de
Full Text Available This study describes the aquatic habitats, species composition, and the insecticide resistance level of the mosquito Culex pipiens pallens in Shandong Province, China. A cross-sectional survey of mosquito larval habitats was conducted from May to November 2014 to determine the species composition and larval abundance. Larvae were collected using the standard dipping technique, and a total of four habitat types were sampled. The fourth instar larvae of Cx. pipiens pallens collected in each habitat type were tested for resistance to five insecticides according to a WHO bioassay. A total of 7,281 mosquito larvae were collected, of which 399 (5.48% were categorized as Anopheles mosquito larvae ( An. sinensis , 6636 (91.14% as culicine larvae ( Cx. pipiens pallens, Cx. tritaeniorhynchus, Cx. halifaxii, and Cx. bitaeniorhynchus , 213 (2.93% as Armigeres larvae, and 33 (0.45% as Aedes larvae ( Aedes albopictus . In addition, a total of 1,149 mosquito pupae were collected. Culex larvae were distributed in all habitats investigated. Tukeys HSD analysis showed that roadside drainages were the most productive habitat type for Culex larvae. Armigeres species were found only in drains, Aedes only in water tanks, and Anopheles in water that was comparatively clear and rich in emergent plants. Bioassay showed that the maximum resistance level of Cx. pipiens pallens was to deltamethrin, while it was lowest to plifenate. The productivity of various mosquitoes in different habitat types is very heterogeneous. It is particularly important to modify human activity and the environment to achieve effective mosquito vector control. For effective larval control, the type of habitat should be considered, and the most productive habitat type should be given priority in mosquito abatement programs.
O'Donnell, Kyle L; Bixby, Mckenzie A; Morin, Kelsey J; Bradley, David S; Vaughan, Jefferson A
Zika virus is an emerging arbovirus of humans in the western hemisphere. With its potential spread into new geographical areas, it is important to define the vector competence of native mosquito species. We tested the vector competency of Aedes vexans (Meigen) from the Lake Agassiz Plain of northwestern Minnesota and northeastern North Dakota. Aedes aegypti (L.) was used as a positive control for comparison. Mosquitoes were fed blood containing Zika virus and 2 wk later were tested for viral infection and dissemination. Aedes vexans (n = 60) were susceptible to midgut infection (28% infection rate) but displayed a fairly restrictive midgut escape barrier (3% dissemination rate). Cofed Ae. aegypti (n = 22) displayed significantly higher rates of midgut infection (61%) and dissemination (22%). To test virus transmission, mosquitoes were inoculated with virus and 16-17 d later, tested for their ability to transmit virus into fluid-filled capillary tubes. Unexpectedly, the transmission rate was significantly higher for Ae. vexans (34%, n = 47) than for Ae. aegypti (5%, n = 22). The overall transmission potential for Ae. vexans to transmit Zika virus was 1%. Because of its wide geographic distribution, often extreme abundance, and aggressive human biting activity, Ae. vexans could serve as a potential vector for Zika virus in northern latitudes where the conventional vectors, Ae. aegypti and Ae. albopictus Skuse, cannot survive. However, Zika virus is a primate virus and humans are the only amplifying host species in northern latitudes. To serve as a vector of Zika virus, Ae. vexans must feed repeatedly on humans. Defining the propensity of Ae. vexans to feed repeatedly on humans will be key to understanding its role as a potential vector of Zika virus. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Fábio Alexandre Leal-Santos
Full Text Available Abstract. This study describes ecological data obtained in a rural area in the State of Mato Grosso, including the insects belonging to the family Culicidae, especially those framed as potential vectors of tropical diseases. In 2015, we collected adult mosquitoes in fragments of forest in a rural area located in Mato Grosso Central West of Brazil. We captured 18,256 mosquitoes of the sub-families Culicinae and Anophelinae and have identified 34 species belonging to 12 genera: Aedes (1 species, Anopheles (8 species, Coquillettidia (1 species, Haemagogus (1 species, Culex (5 species, Psorophora (5 species, Ochlerotatus (4 species, Deinocerites (1 species, Mansonia (4 species, Sabethes (2 species, Limatus (1 species, Wyeomyia (1 species. The family Culicidae presented high richness and abundance, established by diversity indexes (Margalef α =3.26; Shannon H' = 2.09; Simpson D = 0.19 with dominance of the species Anopheles (Nyssorhyncus darlingi Root (89.8%. This species has considerable epidemiological value, considered the main vector of malaria in Mato Grosso. Many species of mosquitoes are vectors of pathogens that cause disease in humans and domestic animals, transmitting pathogens including viruses (arboviruses, filaria worms (helminths and protozoa. Composição de espécies e distribuição da fauna de mosquitos (Diptera: Culicidae e sua importância para doenças transmitidas por vetores em uma área rural do centro-ocidental - Mato Grosso, Brasil Resumo. Este estudo descreve dados ecológicos de uma área rural do Estado de Mato Grosso e dos insetos da família Culicidae especialmente aqueles enquadrados como vetores potenciais de doenças tropicais. Em 2015, coletamos mosquitos adultos em fragmentos de floresta em localidades de áreas rurais no Mato Grosso região Centro Oeste do Brasil. Foram capturados 18.256 exemplares alados de mosquitos das subfamílias Culicinae e Anophelinae e identificadas 34 espécies pertencentes a 12 g
Ruth LM Ferreira
Full Text Available The community structure of insects, especially mosquito larvae, in water held in the fungus Aquascypha hydrophora (Berk. Reid (Stereaceae is reported. The study was done in the Adolpho Ducke Forest Reserve, 26 km east of Manaus, AM, Brazil, from September 1998 through November 1999. The most abundant entomofauna were immature Culicidae (n = 121 91.7%, followed by adult Dytiscidae (n = 3 2.3%, immature Chironomidae (n = 5 3.8% and immature Tipulidae (n = 3 2.3%. Culicidae associated with A. hydrophora comprised species of the subfamilies Anophelinae and Culicinae.
Chemical Compositions of the Peel Essential Oil of Citrus aurantium and its Natural Larvicidal Activity against the Malaria Vector Anopheles stephensi (Diptera: Culicidae in Comparison with Citrus paradisi
Full Text Available Background: Recently, essential oils and extracts derived from plants have received much interest as potential bioactive agents against mosquito vectors.Methods: The essential oils extract from fresh peel of ripe fruit of Citrus aurantium and Citrus paradisi were tested against mosquito vector Anopheles stephensi (Diptera: Culicidae under laboratory condition. Then chemical composition of the essential oil of C. aurantium was analyzed using gas chromatography-mass spectrometry (GC–MS.Results: The essential oils obtained from C. aurantium, and C. paradisi showed good larviciding effect against An. stephensi with LC50 values 31.20 ppm and 35.71 ppm respectively. Clear dose response relationships were established with the highest dose of 80 ppm plant extract evoking almost 100% mortality. Twenty-one (98.62% constituents in the leaf oil were identified. The main constituent of the leaf oil was Dl-limonene (94.81.Conclusion: The results obtained from this study suggest that the limonene of peel essential oil of C. aurantium is promising as larvicide against An. stephensi larvae and could be useful in the search for new natural larvicidal compounds.
Anthony Érico Guimarães
Full Text Available The mosquito (Diptera: Culicidae ecology was studied in areas of Serra do Mar State Park, State of São Paulo, Brazil. Systematized biweekly human bait collections were made three times a day, for periods of 2 or 3 h each, in sylvatic and rural areas for 24 consecutive months (January 1991 to December 1992. A total of 24,943 adult mosquitoes belonging to 57 species were collected during 622 collective periods. Aedes scapularis, Coquillettidia chrysonotum, Cq. venezuelensis, Wyeomyia dyari, Wy. longirostris, Wy. theobaldi and Wy. palmata were more frequently collected at swampy and at flooded areas. Anopheles mediopunctatus, Culex nigripalpus, Ae. serratus, Ae. fulvus, Psorophora ferox, Ps. albipes and the Sabethini in general, were captured almost exclusively in forested areas. An. cruzii, An. oswaldoi and An. fluminensis were captured more frequently in a residence area. However, Cx. quinquefasciatus was the only one truly eusynanthropic. An. cruzii and Ae. scapularis were captured feeding on blood inside and around the residence, indicating that both species, malaria and arbovirus vectors respectively, may be involved in the transmission of these such diseases in rural areas.
Full Text Available Background: Culex quinquefasciatus (Diptera: Culicidae is an important vector for many human diseases. The aim of this study was to evaluate the susceptibility level of larval and adult stages of Cu. quinquefasciatus to different groups of WHO recommended insecticides for vector control.Methods: Larval stages of the Culex mosquitoes were collected from their natural habitats in Rafsanjan County at Kerman Province, southeast of Iran in 2016. Insecticide susceptibility status of adult female Cx. quinquefasciatus against DDT (4%, deltamethrin (0.05%, malathion 5%, and bendiocarb (0.1% were determined using WHO standard insecticide susceptibility test. Additional test was carried out to determine the susceptibility status of larvae of Cx. quinquefasciatus to temephos. Bioassay data were analyzed by Probit program.Results: Cx. quinquefasciatus adults showed resistance to all four groups of the tested insecticides according to the WHO criteria for resistance evaluation. The lethal concentrations for 50% mortality (LC50 and 90% mortality (LC90 of temephos against Cx. quinquefasciatus larvae were 0.18mg/l and 0.78mg/l, respectively. This finding also confirms resistance to temephos based on the WHO recommended instructions for resistance evaluation.Conclusion: Resistance to all groups of the tested insecticides should be considered for future vector control investigations in the study area.
Bashir, Al; Hassan, A Abu; Salmah, M R Che; Rahman, W A
The efficacy of the larvicidal and pupicidal agent (Agnique) MMF was evaluated against larvae of An. arabiensis and Culex (Diptera: Culicidae) under field conditions in Bahary Locality, Khartoum, Sudan. At an applied dosage of 0.25 ml/m2, MMF resulted in 89.4, 79.8 and 88.2% reductions in L3-L4 instars An. arabiensis and 63.5% in Culex larvae (all stages) 24 to 72 hours post-treatment. Pupae were completely eliminated (100%) within 24 hours posttreatment. The earlier instars (L1-L2) of An. arabiensis were more tolerant with a 62.5% reduction at 72 hours post-treatment compared to (L3-L4) instars and pupae. At 7-days post-treatment Agnique gave a 57.5% reduction in L1-L2 and 92.6% in L3-L4 instar larvae of An. arabiensis and 57.3% and 86.4% in Culex larvae and pupae, respectively. We conclude that Agnique can perform effectively against L3-L4 instars and pupae of An. arabiensis for only 1 week, and 3 to 4 days against L1-L2 instars of Culex spp.
Jackson, B T; Stone, C M; Ebrahimi, B; Briët, O J T; Foster, W A
A large-scale mesocosm was constructed and tested for its effectiveness for use in experiments on behaviour, reproduction and adult survivorship in the Afrotropical malaria vector Anopheles gambiae s.s. Giles (Diptera: Culicidae) in temperate climates. The large space (82.69 m(3) ) allowed for semi-natural experiments that increased demand on a mosquito's energetic reserves in an environment of widely distributed resources. A one-piece prefabricated enclosure, made with white netting and vinyl, prevented the ingress of predators and the egress of mosquitoes. Daylight and white materials prompted the mosquitoes to seclude themselves in restricted daytime resting sites and allowed the easy collection of dead bodies so that daily mortality could be assessed accurately using a method that accounts for the loss of a proportion of bodies. Here, daily, age-dependent mortality rates of males and females were estimated using Bayesian Markov chain Monte Carlo simulation. In overnight experiments, mosquitoes successfully located plants and took sugar meals. A 3-week survival trial with a single cohort demonstrated successful mating, blood feeding, oviposition and long life. The relatively low cost of the mesocosm and the performance of the mosquitoes in it make it a viable option for any behavioural or ecological study of tropical mosquitoes in which space and seasonal cold are constraining factors. © 2014 The Royal Entomological Society.
Jackson, Bryan T.; Stone, Christopher M.; Ebrahimi, Babak; Briët, Olivier J.T.; Foster, Woodbridge A.
A large-scale mesocosm was constructed and tested for its effectiveness for experiments on behaviour, reproduction, and adult survivorship of the Afrotropical malaria vector Anopheles gambiae s.s. Giles (Diptera: Culicidae) in temperate climates. The large space (82.69 m3) allowed for semi-natural experiments that increased demand on a mosquito’s energetic reserves in an environment of widely distributed resources. A one-piece prefabricated enclosure, made with white netting and vinyl, prevented the ingress of predators and the egress of mosquitoes. Daylight and white materials prompted the mosquitoes to seclude themselves in restricted daytime resting sites and allowed easy collection of dead bodies so that daily mortality could be assessed accurately, using a method that accounts for a proportion of bodies being lost. Here, daily, age-dependent mortality rates of males and females were estimated using Bayesian Markov Chain Monte Carlo simulation. In overnight experiments, mosquitoes successfully located plants and took sugar meals. A 3-week survival trial with a single-cohort demonstrated successful mating, blood feeding, oviposition, and long life. The relatively low cost of the mesocosm and the performance of the mosquitoes in it make it a viable option for any behavioural or ecological study of tropical mosquitoes where space and seasonal cold are constraining factors. PMID:25294339
Alencar, Jeronimo; Marcondes, Carlos Brisola; Serra-Freire, Nicolau Maués; Lorosa, Elias Seixas; Pacheco, Juliana Barreto; Guimarães, Anthony Erico
We present the identification of bloodfeeding sources of Haemagogus (Haemagogus) capricornii Lutz and Haemagogus (Conopostegus) leucocelaenus (Dyar & Shannon) (Diptera: Culicidae) from different regions of Brazil, as analyzed by precipitin tests. Anti-sera for bird, bovine, equine, human, opossum, and rodent were used. Two hundred one mosquitoes were examined (147 Hg. leucocelaenus and 54 Hg. capricornii), of which 177 reacted for some anti-serum. For Hg. leucocelaenus, 86 (68.3%) reacted to one blood source, 38 (30.2%) to two sources, and two (1.6%) to three sources; the combinations of bird + human (18.4%), bird + rodent (15.8%), and bird + marsupial (15.8%) were the most frequent. For Hg. capricornii, 34 (66.7%) reacted to one blood source; combinations bird + rodent (37.5%) and bird + marsupial (25%) were the most frequent combinations. Mosquito preference for bloodfeeding sources was different in these areas, possibly because of the availability of sources. This diversity of sources can have important epidemiological implications.
Appadurai Daniel Reegan
Full Text Available Ecbolin A and ecbolin B were isolated from ethyl acetate extract of Ecbolium viride (Forsk. Alston root and evaluated for larvicidal and growth disturbance activities against Aedes aegypti L. (Diptera: Culicidae. For larvicidal activity, the third instar larvae of A. aegypti were exposed to different concentrations viz., 1.0, 2.5, 5.0 and 10 ppm for each compound. Among the two compounds screened, ecbolin B recorded highest larvicidal activity with LC50 and LC90 values of 0.70 and 1.42 ppm, respectively. In control, the larval behaviour was normal. The active compound ecbolin B was tested for growth disruption activity at sub lethal concentrations viz., 0.5, 1.0 ppm and observed for malformation like larval gut elongation, larval longevity, intermediates, malformed adults, failed adult emergence and compared with methoprene. The results showed significant level of larva–pupa intermediates, pupa–adult intermediates, malformed adult emergence and less adult formation against A. aegypti. The histopathological results revealed a severe damage on the midgut epithelial columnar cells (CC and cuboidal cells (CU in ecbolin B treated larvae of A. aegypti. Similarly peritrophic membrane (pM was also observed to be damaged in the treated larvae. The present results suggest that, ecbolin B could be used as a larvicidal agent against dengue vector A. aegypti.
Cetin, Huseyin; Yanikoglu, Atila; Cilek, James E
The naturally-derived insecticide spinosad (Conserve SC) was evaluated against larval Culex pipiens L. (Diptera: Culicidae) under laboratory and field conditions in Antalya, Turkey. Laboratory bioassays showed that the 24 h LC50 and LC90 against late 3rd and early 4th instars were estimated at 0.027 and 0.111 parts per million, respectively, while adult emergence was eliminated at concentrations above 0.06 ppm. Larval mortality from septic tanks that were treated with spinosad at rates of 25, 50, 100, and 200 g ai/ha ranged between 22 to 78% 1 day after application. At 7 days post-treatment, larval mortality ranged from 2 to 50% and at 14 days mortality was septic tanks treated at 100 and 200 g ai/ha resulted in an elimination of Cx. pipiens larvae 7 days after treatment. After this time, larval reduction declined to 79 and 83%, respectively, 14 days after treatment. Larval reduction in septic tanks treated at the two lowest rates (i.e. 25 and 50 g ai/ha) ranged from 14 to 74% during the 14-day study. These results indicated that spinosad can be considered an effective larvicide for treatment of septic tanks against Cx. pipiens.
Karla Rejane de Andrade Porto
Full Text Available Abstract: INTRODUCTION: Dengue fever is a viral disease transmitted by the Aedes aegypti Linn. (1792 (Diptera: Culicidae mosquito, which is endemic in several regions of Brazil. Alternative methods for the control of the vector include botanical insecticides, which offer advantages such as lower environmental contamination levels and less likelihood of resistant populations. Thus, in this study, the ability of botanical insecticide formulations to inhibit the activity of the liver enzymes serum cholinesterase and malate dehydrogenase was evaluated. METHODS: Inhibition profiles were assessed using in vitro assays for cholinesterase and malate dehydrogenase activity and quantitated by ultraviolet-visible spectroscopy at 410nm to 340nm. RESULTS Insecticide products formulated from cashew nutshell liquid [A] and ricinoleic acid [B] showed cholinesterase activity levels of 6.26IU/mL and 6.61IU/mL, respectively, while the control level for cholinesterase was 5-12IU/mL. The products did not affect the level of 0.44IU/mL established for malate dehydrogenase, as the levels produced by [A] and [B] were 0.43IU/mL and 0.45IU/mL, respectively. CONCLUSIONS Our findings show that in vitro testing of the formulated products at concentrations lethal to A. aegypti did not affect the activity of cholinesterase and malate dehydrogenase, indicating the safety of these products.
Porto, Karla Rejane de Andrade; Motti, Priscilla Rezende; Machado, Alexandre Alves; Roel, Antonia Railda
Dengue fever is a viral disease transmitted by the Aedes aegypti Linn. (1792) (Diptera: Culicidae) mosquito, which is endemic in several regions of Brazil. Alternative methods for the control of the vector include botanical insecticides, which offer advantages such as lower environmental contamination levels and less likelihood of resistant populations. Thus, in this study, the ability of botanical insecticide formulations to inhibit the activity of the liver enzymes serum cholinesterase and malate dehydrogenase was evaluated. Inhibition profiles were assessed using in vitro assays for cholinesterase and malate dehydrogenase activity and quantitated by ultraviolet-visible spectroscopy at 410nm to 340nm. Insecticide products formulated from cashew nutshell liquid [A] and ricinoleic acid [B] showed cholinesterase activity levels of 6.26IU/mL and 6.61IU/mL, respectively, while the control level for cholinesterase was 5-12IU/mL. The products did not affect the level of 0.44IU/mL established for malate dehydrogenase, as the levels produced by [A] and [B] were 0.43IU/mL and 0.45IU/mL, respectively. Our findings show that in vitro testing of the formulated products at concentrations lethal to A. aegypti did not affect the activity of cholinesterase and malate dehydrogenase, indicating the safety of these products.
Gerson A. Müller
Full Text Available Crepuscular activity of culicids (Diptera, Culicidae in the peridomicile and in the remaining riparian forest in Tibagi river, State of Paraná, Brazil. Human-attracted mosquitoes were collected for one hour, around sunset time (half hour before and half after, from April to December 2006, in two environments (riparian forest and near houses, in Tibagi river basin, Palmeira municipality, State of Paraná. Seven-hundred forty-nine mosquitoes, belonging to 13 species, were collected. Psorophora champerico Dyar & Knab, 1906 (42.86% and Psorophora discrucians (Walker, 1856 (40.59% were the most frequent species. No significant differences between quantities of Ps. champerico (t = -0.792; d.f. = 16; p = 0.43 and Ps. discrucians (t = 0.689; d.f. = 16; p = 0.49 obtained in riparian forest and near houses were observed, indicating similar conditions for crepuscular activity of these species in both environments. Psorophora champerico and Ps. discrucians responded (haematophagic activity to environmental stimuli associated with the twilight hours differently in distinct habitats studied. The former species is registered for the first time in the Atlantic forest biome.
Adriana Félix do Anjos
Full Text Available A alteração da paisagem natural pode gerar mudanças que favorecem odesenvolvimento e proliferação de determinadas espécies de Culicidae, em detrimento de outras que se deslocam para outros locais ou são extintas. Baseando-se nestas mudanças, algumas espécies podem ser utilizadas como bioindicadores do grau de degradação ambiental. O presente estudo tem como objetivo analisar a composição e riqueza deCulicidae, em dois ambientes em área de Floresta Atlântica, e avaliar se as espécies encontradas indicam o grau de preservação dos fragmentos estudados. As coletas foram realizadas em dois ambientes, denominados Carvalho e Trilha, em área de Floresta Atlântica(Mananciais da Serra, no Estado do Paraná - Brasil, nos meses de dezembro/2002 a maio/2003, utilizando-se um aspirador elétrico manual. Foram identificadas 48 espécies de 636 espécimes de Culicidae. A composição taxonômica e riqueza das espécies de Culicidaediferenciaram-se entre os ambientes estudados, provavelmente, influenciadas pelo estado de preservação dos fragmentos florestais. Os maiores valores de riqueza observados no Carvalho, assim como o predomínio das espécies da tribo Sabethini e Kerteszia sugeremreduzida ação antrópica neste fragmento florestal. De modo contrário, a composição das espécies e os menores valores de riqueza observadas na Trilha indicam grau alto de degradação ambiental.Modifications in the landscape can lead to the development and proliferation of some Culicidae species, in detriment of others. As a result, some species may be forced to move to other places or become locally extinct. Based on these changes, some species can beused as bioindicators of environmental degradation. The aim of this study was to assess Culicidae composition and richness in two Atlantic Forest sites (Carvalho and Trilha; State of Paraná, Brazil, and to evaluate whether they can be used as indicators of environmental degradation of these sites
Navarro, J.C.; Enríquez, S.; Campaña, Y.; Benítez Ortíz, W.
Two new records of Sabethes mosquitoes (Culicidae: Nematocera) are reported for Ecuador with the respective extension of their geographical distribution in the Neotropics: Sabethes intermedius Lutz and Sabethes soperi Lane & Cerqueira, from the provinces of Napo (Amazon) into the Natural Reserve of Colonso-Chalupas at 1,200 m altitude, beside Tena city, Ecuador. Both species are considered as potential vectors of sylvatic Yellow Fever virus and Mayaro virus. Information on collection local...
Gerson A. Müller
Full Text Available Crepuscular activity of culicids (Diptera, Culicidae in the peridomicile and in the remaining riparian forest in Tibagi river, State of Paraná, Brazil. Human-attracted mosquitoes were collected for one hour, around sunset time (half hour before and half after, from April to December 2006, in two environments (riparian forest and near houses, in Tibagi river basin, Palmeira municipality, State of Paraná. Seven-hundred forty-nine mosquitoes, belonging to 13 species, were collected. Psorophora champerico Dyar & Knab, 1906 (42.86% and Psorophora discrucians (Walker, 1856 (40.59% were the most frequent species. No significant differences between quantities of Ps. champerico (t = -0.792; d.f. = 16; p = 0.43 and Ps. discrucians (t = 0.689; d.f. = 16; p = 0.49 obtained in riparian forest and near houses were observed, indicating similar conditions for crepuscular activity of these species in both environments. Psorophora champerico and Ps. discrucians responded (haematophagic activity to environmental stimuli associated with the twilight hours differently in distinct habitats studied. The former species is registered for the first time in the Atlantic forest biome.Atividade crepuscular de culicídeos (Diptera, Culicidae no peridomicílio e remanescentes de matas ciliares do Rio Tibagi. Estado do Paraná, Brasil. Mosquitos atraídos por humanos foram coletados por uma hora em torno do crepúsculo vespertino (meia hora antes e meia hora depois, de abril a dezembro de 2006, em dois locais (mata ciliar e peridomicílio na bacia do Rio Tibagi, município de Palmeira, Estado do Paraná. Foram capturados 749 mosquitos distribuídos em 13 espécies. Psorophora champerico Dyar & Knab, 1906 (42,86% e Ps. discrucians (Walker, 1856 (40,59% foram as espécies mais freqüentes. Não foram registradas diferenças significativas entre as médias de indivíduos capturados entre os pontos de mata ciliar e peridomicílio para Ps. champerico (t = -0,792; g.l. = 16; p = 0
Smith, C; Baldwin, A H; Sullivan, J; Leisnham, P T
Elevated atmospheric CO2 can alter aquatic communities via changes in allochthonous litter inputs. We tested effects of atmospheric CO2 on the invasive Aedes albopictus (Skuse) and native Aedes triseriatus (Say) (Diptera: Culicidae) via changes in competition for microbial food or resource inhibition/toxicity. Quercus alba L. litter was produced under elevated (879 ppm) and ambient (388 ppm) atmospheric CO2. Saplings grown at elevated CO2 produced greater litter biomass, which decayed faster and leached more tannins than saplings at ambient CO2. Competition was tested by raising larvae in different species and density combinations provisioned with elevated- or ambient-CO2 litter. Species-specific performance to water conditions was tested by providing single-species larval cohorts with increasing amounts of elevated- or ambient-CO2 litter, or increasing concentrations of tannic acid. Larval densities affected some fitness parameters of Ae. albopictus and Ae. triseriatus, but elevated-CO2 litter did not modify the effects of competition on population growth rates or any fitness parameters. Population growth rates and survival of each species generally were affected negatively by increasing amounts of both elevated- and ambient-CO2 litter from 0.252 to 2.016 g/liter, and tannic acid concentrations above 100 mg/liter were entirely lethal to both species. Aedes albopictus had consistently higher population growth rates than Ae. triseriatus. These results suggest that changes to litter production and chemistry from elevated CO2 are unlikely to affect the competitive outcome between Ae. albopictus and Ae. triseriatus, but that moderate increases in litter production increase population growth rates of both species until a threshold is exceeded that results in resource inhibition and toxicity.
Predation and control efficacies of Misgurnus mizolepis (Cypriniformes: Cobitidae) toward Culex pipiens molestus (Diptera: Culicidae) and fish toxicity of temephos in laboratory and septic tank conditions.
Chae, Seong Chun; Kwon, Young Hyun; Min, Kyung Il; Kim, Hyung Soo; Kim, Nam-Jin; Kim, Jun-Ran; Son, Bong Gi; Ahn, Young-Joon
Culex pipiens molestus Forskal (Diptera: Culicidae) is the dominant mosquito species in septic tanks in South Korea. An assessment was made of the biological control potential of mud loaches, Misgurnus mizolepis Günther (Cypriniformes: Cobitidae), toward Cx. p. molestus larvae in laboratory and septic tanks. Results were compared with those of temephos 20% emulsifiable concentrate. In laboratory tests, all mud loaches survived on sedimentation chamber- and effluent chamber-collected water of aerobic septic tanks (ASTs), whereas all mud loaches died within 3-12 h after introduction into sedimentation chamber- and effluent chamber-collected water of anaerobic septic tanks, Gill hyperplasia and hemorrhages at the bases of pectoral fins were detected in all dead mud loaches. These appeared to have been caused by bacterial disease, rather than the physical and chemical characteristics of the septic tank water. A mud loach consumed an average range of 1,072-1,058 larvae of Cx. p. molestus in the AST water at 24 h. At the manufacturer's recommended rate (10 ml/ton) in the AST water, the temephos formulation did not cause fish mortality. In the AST experiment, predation of mosquito larvae by mud loaches at a release rate of one fish per 900 mosquito larvae resulted in complete mosquito control from the third day after treatment throughout the 18-wk survey period, compared with temephos 20% emulsifiable concentrate-treated AST water (reduction rate, 40% at 28 days after treatment). Reasonable mosquito control in aerobic septic tanks can be achieved by mosquito breeding season stocking of a rate of one mud loach per 900 mosquito larvae.
Popko, David A; Henke, Jennifer A; Mullens, Bradley A; Walton, William E
Commercially available formulations of two entomopathogenic fungi, Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Clavicipitaceae) and Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae), were assessed for control of Culex quinquefasciatus Say (Diptera: Culicidae) in underground storm drain systems (USDS) in the Coachella Valley of southern California. Each of three treatments, the two fungi or a water control, was applied to 1 m2 of vertical wall at eight USDS sites in spring and autumn of 2015. Fungal infectivity and lethality were assessed at 1 d and 1, 2, and 4 wk post-application. Overnight bioassays using adult lab-reared female mosquitoes were carried out on the treated USDS wall areas and then mosquitoes were held in the laboratory for up to 21 d to allow fungal infections to be expressed. Postmortem fungal sporulation was assessed up to 2 wk at 100% humidity. Mosquito-fungal interactions also were assessed in bioassays of the three treatments on filter paper exposed to USDS conditions during autumn. Metarhizium anisopliae killed mosquitoes faster than B. bassiana; nevertheless, both freshly applied formulations caused greater than 80% mortality. Fungal persistence declined significantly after 1 wk under USDS conditions, but some infectivity persisted for more than 4 wk. Beauveria bassiana was more effective against Cx. qinquefasciatus in the spring, while M. anisopliae was more effective in the cooler conditions during autumn. USDS environmental conditions (e.g., temperature, relative humidity, standing water) influenced fungal-related mortality and infection of Cx. quinquefasciatus. The utility of these fungal formulations for mosquito abatement in the Coachella Valley and implications for fungal control agents in USDS environments are discussed. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: email@example.com.
Encontro de Haemagogus (Conopostegus leucocelaenus (Diptera: Culicidae, no Município de Porto Alegre, Estado do Rio Grande do Sul Finding of Haemagogus (Conopostegus leucocelaenus (Diptera: Culicidae, in the municipality of Porto Alegre, State of Rio Grande do Sul
Almério de Castro Gomes
Full Text Available Em novembro de 2006, foi realizada uma investigação entomológica numa mata nativa do município de Porto Alegre, Estado do Rio Grande do Sul. O resultado foi a captura de várias espécies Culicidae, incluindo o primeiro registro da presença de Haemagogus leucocelaenus na localidade. Esta espécie é considerada vetora do vírus da febre amarela em alguns municípios do Estado, motivando esta comunicação para alertar sobre o potencial da área para circulação do agente etiológico desta doença.In November 2006, an entomological investigation was carried out in a native forest in the municipality of Porto Alegre, State of Rio Grande do Sul. The result was the capture of several Culicidae species, including the first recording of the presence of Haemagogus leucocelaenus in this locality. This species is considered to be a vector for the yellow fever virus in some municipalities of this State, and this was the motivation for the present communication, in order to warn regarding the potential of this area for circulation of the etiological agent for this disease.
Nur Endah Wahyuningsih; Ramauli Agustina Sihit
The control of dengue hemorrhagic fever (DHF) it is important to control the vector, i.e. Aedes aegypti (Linnaeus) and Ae. albopictus (Skuse). Usually, controls of these vectors are done using chemical insecticides. Research on mosquito resistance has been done, but the impact of mosquitoes that survive after synthetic (chemical) insecticides application has not been studied. The aim of this research was to analyze the differences of fecundity, fertility and vitality rate of mosquitoes that w...
Full Text Available Abstract Background Although malaria disappeared from southern France more than 60 years ago, suspicions of recent autochthonous transmission in the French Mediterranean coast support the idea that the area could still be subject to malaria transmission. The main potential vector of malaria in the Camargue area, the largest river delta in southern France, is the mosquito Anopheles hyrcanus (Diptera: Culicidae. In the context of recent climatic and landscape changes, the evaluation of the risk of emergence or re-emergence of such a major disease is of great importance in Europe. When assessing the risk of emergence of vector-borne diseases, it is crucial to be able to characterize the arthropod vector's spatial distribution. Given that remote sensing techniques can describe some of the environmental parameters which drive this distribution, satellite imagery or aerial photographs could be used for vector mapping. Results In this study, we propose a method to map larval and adult populations of An. hyrcanus based on environmental indices derived from high spatial resolution imagery. The analysis of the link between entomological field data on An. hyrcanus larvae and environmental indices (biotopes, distance to the nearest main productive breeding sites of this species i.e., rice fields led to the definition of a larval index, defined as the probability of observing An. hyrcanus larvae in a given site at least once over a year. Independent accuracy assessments showed a good agreement between observed and predicted values (sensitivity and specificity of the logistic regression model being 0.76 and 0.78, respectively. An adult index was derived from the larval index by averaging the larval index within a buffer around the trap location. This index was highly correlated with observed adult abundance values (Pearson r = 0.97, p An. hyrcanus larval and adult populations from the landscape indices. Conclusion This work shows that it is possible to use
Ovicidal, larvicidal and adulticidal properties of Asparagus racemosus (Willd.) (Family: Asparagaceae) root extracts against filariasis (Culex quinquefasciatus), dengue (Aedes aegypti) and malaria (Anopheles stephensi) vector mosquitoes (Diptera: Culicidae).
Govindarajan, Marimuthu; Sivakumar, Rajamohan
Several diseases are associated to the mosquito-human interaction. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikungunya fever, West Nile virus and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. The present investigation was undertaken to study the ovicidal, larvicidal and adulticidal activities of crude hexane, ethyl acetate, benzene, chloroform and methanol extracts of root of Asparagus racemosus were assayed for their toxicity against three important vector mosquitoes, viz., Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera: Culicidae). The mean percent hatchability of the eggs was observed after 48 h post-treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. All the five solvent extracts showed moderate ovicidal activity; however, the methanol extract showed the highest ovicidal activity. The methanol extract of Asparagus racemosus against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi exerted 100% mortality (zero hatchability) at 375, 300 and 225 ppm, respectively. Control eggs showed 99-100% hatchability. The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in methanol extract of root of Asparagus racemosus against the larvae of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi with the LC50 and LC90 values were 115.13, 97.71 and 90.97 ppm and 210.96, 179.92, and 168.82 ppm, respectively. The adult mortality was observed after 24 h recovery period. The plant crude extracts showed dose-dependent mortality. At higher concentrations, the adult showed restless movement for some times with abnormal wagging and then died. Among the extracts tested, the highest adulticidal activity was observed in
Dandalo, Leonard C; Brooke, Basil D; Munhenga, Givemore; Lobb, Leanne N; Zikhali, Jabulani; Ngxongo, Sifiso P; Zikhali, Phineas M; Msimang, Sipho; Wood, Oliver R; Mofokeng, Mohlominyana; Misiani, Eunice; Chirwa, Tobias; Koekemoer, Lizette L
Anopheles arabiensis (Patton; Diptera: Culicidae) is a major malaria vector in the southern African region. In South Africa, effective control of this species using indoor-based interventions is reduced owing to its tendency to rest outdoors. As South Africa moves towards malaria elimination there is a need for complementary vector control strategies. One of the methods under consideration is the use of the sterile insect technique (SIT). Key to the successful implementation of an SIT programme is prior knowledge of the size and spatial distribution of the target population. Understanding mosquito population dynamics for both males and females is critical for efficient programme implementation. It is thus necessary to use outdoor-based population monitoring tools capable of sampling both sexes of the target population. In this project mosquito surveillance and evaluation of tools capable of collecting both genders were carried out at Mamfene in northern KwaZulu-Natal Province, South Africa, during the period January 2014 to December 2015. Outdoor- and indoor-resting Anopheles mosquitoes were sampled in three sections of Mamfene over the 2-yr sampling period using modified plastic buckets, clay pots and window exit traps. Morphological and molecular techniques were used for species identifications of all samples. Wild-caught adult females were tested for Plasmodium falciparum (Welch; Haemosporida: Plasmodiidae) infectivity. Out of 1,705 mosquitoes collected, 1,259 (73.8%) and 255 (15%) were identified as members of either the Anopheles gambiae complex or Anopheles funestus group respectively. An. arabiensis was the most abundant species contributing 78.8% of identified specimens. Mosquito density was highest in summer and lowest during winter. Clay pots yielded 16.3 mosquitoes per trap compared to 10.5 for modified plastic buckets over the 2-yr sampling period. P. falciparum infection rates for An. arabiensis were 0.7% and 0.5% for 2014 and 2015, respectively
Okech, Bernard; Arai, Meiji; Matsuoka, Hiroyuki
Xanthurenic acid (XA), produced as a byproduct during the biosynthesis of insect eye pigment (ommochromes), is a strong inducer of Plasmodium gametogenesis at very low concentrations. In previous studies, it was shown that XA is present in Anopheles stephensi (Diptera: Culicidae) mosquito salivary glands and that during blood feeding the mosquitoes ingested their own saliva into the midgut. Considering these two facts together, it is therefore likely that XA is discharged with saliva during blood feeding and is swallowed into the midgut where it exerts its effect on Plasmodium gametocytes. However, the quantities of XA in the salivary glands and midgut are unknown. In this study, we used high performance liquid chromatography with electrochemical detection to detect and quantify XA in the salivary glands and midgut. Based on the results of this study, we found 0.28+/-0.05 ng of XA in the salivary glands of the mosquitoes, accounting for 10% of the total XA content in the mosquito whole body. The amounts of XA in the salivary glands reduced to 0.13+/-0.06 ng after mosquitoes ingested a blood meal. Approximately 0.05+/-0.01 ng of XA was detected in the midgut of nonblood fed An. stephensi mosquitoes. By adding synthetic tryptophan as a source of XA into larval rearing water (2 mM) or in sugar meals (10 mM), we evaluated whether XA levels in the mosquito (salivary glands, midgut, and whole body) were boosted and the subsequent effect on infectivity of Plasmodium berghei in the treated mosquito groups. A female specific increase in XA content was observed in the whole body and in the midgut of mosquito groups where tryptophan was added either in the larval water or sugar meals. However, XA in the salivary glands was not affected by tryptophan addition to larval water, and surprisingly it reduced when tryptophan was added to sugar meals. The P. berghei oocyst loads in the mosquito midguts were lower in mosquitoes fed tryptophan treated sugar meals than in mosquitoes
Suresh, Udaiyan; Murugan, Kadarkarai; Benelli, Giovanni; Nicoletti, Marcello; Barnard, Donald R; Panneerselvam, Chellasamy; Kumar, Palanisamy Mahesh; Subramaniam, Jayapal; Dinesh, Devakumar; Chandramohan, Balamurugan
Mosquitoes are vectors of devastating pathogens and parasites, causing millions of deaths every year. Dengue is a mosquito-borne viral infection found in tropical and subtropical regions around the world. Recently, transmission has strongly increased in urban and semiurban areas, becoming a major international public health concern. Aedes aegypti (Diptera: Culicidae) is the primary vector of dengue. The use of synthetic insecticides to control Aedes mosquitoes lead to high operational costs and adverse nontarget effects. In this scenario, eco-friendly control tools are a priority. We proposed a novel method to synthesize silver nanoparticles using the aqueous leaf extract of Phyllanthus niruri, a cheap and nontoxic material. The UV-vis spectrum of the aqueous medium containing silver nanostructures showed a peak at 420 nm corresponding to the surface plasmon resonance band of nanoparticles. SEM analyses of the synthesized nanoparticles showed a mean size of 30-60 nm. EDX spectrum showed the chemical composition of the synthesized nanoparticles. XRD highlighted that the nanoparticles are crystalline in nature with face-centered cubic geometry. Fourier transform infrared spectroscopy (FTIR) of nanoparticles exhibited prominent peaks 3,327.63, 2,125.87, 1,637.89, 644.35, 597.41, and 554.63 cm(-1). In laboratory assays, the aqueous extract of P. niruri was toxic against larval instars (I-IV) and pupae of A. aegypti. LC50 was 158.24 ppm (I), 183.20 ppm (II), 210.53 ppm (III), 210.53 ppm (IV), and 358.08 ppm (pupae). P. niruri-synthesized nanoparticles were highly effective against A. aegypti, with LC50 of 3.90 ppm (I), 5.01 ppm (II), 6.2 ppm (III), 8.9 ppm (IV), and 13.04 ppm (pupae). In the field, the application of silver nanoparticles (10 × LC50) lead to A. aegypti larval reduction of 47.6%, 76.7% and 100%, after 24, 48, and 72 h, while the P. niruri extract lead to 39.9%, 69.2 % and 100 % of reduction, respectively. In adulticidal experiments, P. niruri extract
Abella-Medrano, Carlos Antonio; Ibáñez-Bernal, Sergio; MacGregor-Fors, Ian; Santiago-Alarcon, Diego
Land-use change has led to a dramatic decrease in total forest cover, contributing to biodiversity loss and changes of ecosystems' functions. Insect communities of medical importance can be favored by anthropogenic alterations, increasing the risk of novel zoonotic diseases. The response of mosquito (Diptera: Culicidae) abundance and richness to five land-use types (shade coffee plantation, cattle field, urban forest, peri-urban forest, well-preserved montane cloud forest) and three seasons ("dry", "rainy" and "cold") embedded in a neotropical montane cloud forest landscape was evaluated. Standardized collections were performed using 8 CDC miniature black-light traps, baited with CO2 throughout the year. Generalized additive mixed models were used to describe the seasonal and spatial trends of both species richness and abundance. Rank abundance curves and ANCOVAs were used to detect changes in the spatial and temporal structure of the mosquito assemblage. Two cluster analyses were conducted, using 1-βsim and the Morisita-Horn index to evaluate species composition shifts based on incidences and abundances. A total of 2536 adult mosquitoes were collected, belonging to 9 genera and 10 species; the dominant species in the study were: Aedes quadrivittatus, Wyeomyia adelpha, Wy. arthrostigma, and Culex restuans. Highest richness was recorded in the dry season, whereas higher abundance was detected during the rainy season. The urban forest had the highest species richness (n = 7) when compared to all other sites. Species composition cluster analyses show that there is a high degree of similarity in species numbers across sites and seasons throughout the year. However, when considering the abundance of such species, the well-preserved montane cloud forest showed significantly higher abundance. Moreover, the urban forest is only 30 % similar to other sites in terms of species abundances, indicating a possible isolating role of the urban environment. Mosquito
Mohamad, N; Zuharah, W F
Toxorhynchites splendens larvae are a natural predator of dengue vector mosquito larvae, Aedes albopictus. This study was carried out to evaluate the predation rate of Tx. splendens third instar larvae on Ae. albopictus larvae in 24 h. Each predator was offered prey at a density between 10 to 50 individuals. Predation rate of Tx. splendens were also tested with two manipulated factors; various types of container and different water volumes. The experiment was evaluated in man-made containers (tin cans, plastic drinking glasses and rubber tires) and natural container (bamboo stumps) which were filled with different water volumes (full, half full, 1/4 full, and 1/8 full). The prey density and the characteristics of the container were found as significant factors which influence the predation rate of Tx. splendens. The predator consumed significantly more prey at higher prey densities (40 and 50 preys) compared to the lowest density (10 preys) (F=3.935, df=4, p=0.008). The results showed significantly higher consumption in horizontal shaped container of rubber tire than in vertical shape of bamboo stumps (F=3.100, df=3, p=0.029). However, the water volume had no significant effect on predation rate of Tx. splendens (F=1.736, df=3, p=0.162). We generally suggest that Tx. splendens is best to be released in discarded tires or any other containers with horizontal shape design with wide opening since Tx. splendens can become more effective in searching prey in this type of container design. This predator is also a suitable biocontrol candidates to be introduced either in wet and dry seasons in Malaysia.
Rochlin, Ilia; Kawalkowski, Margaret; Ninivaggi, Dominick V
Container-inhabiting Aedes are among the most medically important mosquito vectors of diseases. They also impact health and quality of life by their persistent and severe biting. Monitoring of container-inhabiting Aedes species is challenging due to the need for specialized traps and lures. Biogents Sentinel (BGS) trap has become a standard for Aedes albopictus (Skuse) surveillance; however, it has substantial problems with durability, quality of construction, and sample exposure to the elements. The goal of this study was to develop a methodology for collecting medically important container-inhabiting Aedes species in numbers sufficient for population trend analysis, control efficacy studies, and pathogen testing. Mosquito Magnets (MM) baited with BG lure and R-octenol were selected as the most practical alternative to BGS, collecting significantly more Ae. albopictus (32.1 ± 0.7 vs. 5.6 ± 0.1), Aedes japonicus (Theobald) (10.1 ± 0.4 vs. 1.2 ± 0.02), and Aedes triseriatus (Say) (0.9 ± 0.04 vs. 0.04 ± 0.004) females on average per trapping under a variety of weather conditions. MM can be particularly useful for long-term surveillance or when large numbers of specimens are required for pathogen isolation, such as at the sites with suspected dengue or chikungunya transmission. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Bromeliad-associated mosquitoes from Atlantic forest in Santa Catarina Island, southern Brazil (Diptera, Culicidae, with new records for the State of Santa Catarina Mosquitos associados a bromélias em Mata Atlântica na Ilha de Santa Catarina, sul do Brasil (Diptera, Culicidae, com novos registros para o Estado de Santa Catarina
Gerson Azulim Müller
Full Text Available Bromeliad-associated mosquitoes (Diptera: Culicidae in Atlantic Forest in Florianópolis, Santa Catarina, southern Brazil, were studied, examining plants of Vriesea philippocoburgi Wawra and Aechmea lindenii (E. Morren Baker var. lindenii at secondary Atlantic rain forest, and A. lindenii and Vriesea friburgensis Mez var. paludosa (L. B. Smith at "restinga" per month, during 12 months. No immature forms of mosquitoes were collected from A. lindenii in the secondary forest. Collections obtained 368 immature mosquitoes, none of them from A. lindenii from rain forest. Culex (Microculex spp. constituted 79.8% of the total, Wyeomyia (Phoniomyia spp. 17.93%, and Anopheles (Kerteszia cruzii (Dyar & Knab, 1908 only 1.36%. The study shows the great predominance of species of medical importance not yet proved, and the small number of immature stages of anopheline mosquitoes. The rainfall, but not the mean temperatures, significantly influenced the quantity of mosquitoes from V. philippocoburgi. Significant differences between the quantities of immature forms of all the bromeliad species were found, and the shape of the plants could be important to the abundance of mosquitoes. All six species of Cx. (Microculex found are recorded for the first time in the State of Santa Catarina, and all six species of Wyeomyia (Phoniomyia are recorded for the first time in bromeliads in this state.Mosquitos (Diptera: Culicidae associados a bromélias em Mata Atlântica na Ilha de Santa Catarina, no Estado de Santa Catarina, foram estudados. Foram examinadas mensalmente plantas de Vriesea philippocoburgi Wawra e Aechmea lindenii (E. Morren Baker var. lindenii de floresta atlântica pluvial ombrófila e A. lindenii e Vriesea friburgensis Mez var. paludosa (L. B. Smith de restinga, durante 12 meses. As coletas resultaram em 368 formas imaturas de mosquitos, sendo que nenhuma foi coletada em A. lindenii de mata ombrófila. Culex (Microculex spp. constituíram 79,8% do total
Rueda-Páramo, M E; Montalva, C; Arruda, W; Fernandes, É K K; Luz, C; Humber, R A
A project from 2013 to 2017 sought to discover pathogenic fungi and oomycetes from dipteran species that are vectors of major diseases of humans and animals in central Brazil and to begin evaluating the potential of these pathogens as potential biological control agents concentrated on mosquito larvae. Some collecting sites proved to be especially productive for pathogens of naturally occurring mosquito species and for placements of healthy sentinel larvae of Aedes aegypti in various sorts of containers in a gallery forest in the Santa Branca Ecoturismo Private Reserve of Natural Patrimony (RPPN) near Terezópolis de Goiás (GO). Collections during May-April of 2016 and February 2017 yielded a few dead mosquito larvae of an undetermined Onirion sp. (Culicidae: Sabethini) whose hemocoels contained many ovoid, thick-walled, yellow-golden to golden-brown, ovoid thick-walled resistant sporangia, 38.3±4×22.8±2.3µm, decorated by numerous, closely and randomly spaced punctations of variable size and shape. These were the first indisputable collections from Brazil of any Coelomomyces species. Comparisons of the morphology of these sporangia with those of other species of Coelomomyces, confirmed that this Brazilian fungus represented a new species that is described here as Coelomomyces santabrancae. Copyright © 2017. Published by Elsevier Inc.
Marques Tatiani C
Full Text Available Abstract Background The most substantial and best preserved area of Atlantic Forest is within the biogeographical sub-region of Serra do Mar. The topographic complexity of the region creates a diverse array of microclimates, which can affect species distribution and diversity inside the forest. Given that Atlantic Forest includes highly heterogeneous environments, a diverse and medically important Culicidae assemblage, and possible species co-occurrence, we evaluated mosquito assemblages from bromeliad phytotelmata in Serra do Mar (southeastern Brazil. Methods Larvae and pupae were collected monthly from Nidularium and Vriesea bromeliads between July 2008 and June 2009. Collection sites were divided into landscape categories (lowland, hillslope and hilltop based on elevation and slope. Correlations between bromeliad mosquito assemblage and environmental variables were assessed using multivariate redundancy analysis. Differences in species diversity between bromeliads within each category of elevation were explored using the Renyi diversity index. Univariate binary logistic regression analyses were used to assess species co-occurrence. Results A total of 2,024 mosquitoes belonging to 22 species were collected. Landscape categories (pseudo-F value = 1.89, p = 0.04, bromeliad water volume (pseudo-F = 2.99, p = 0.03 and bromeliad fullness (Pseudo-F = 4.47, p An. homunculus was associated with Cx. ocellatus and the presence of An. cruzii was associated with Cx. neglectus, Cx. inimitabilis fuscatus and Cx. worontzowi. Anopheles cruzii and An. homunculus were taken from the same bromeliad, however, the co-occurrence between those two species was not statistically significant. Conclusions One of the main findings of our study was that differences in species among mosquito assemblages were influenced by landscape characteristics. The bromeliad factor that influenced mosquito abundance and assemblage structure was fullness. The findings of the current
Nur Endah Wahyuningsih
Full Text Available The control of dengue hemorrhagic fever (DHF it is important to control the vector, i.e. Aedes aegypti (Linnaeus and Ae. albopictus (Skuse. Usually, controls of these vectors are done using chemical insecticides. Research on mosquito resistance has been done, but the impact of mosquitoes that survive after synthetic (chemical insecticides application has not been studied. The aim of this research was to analyze the differences of fecundity, fertility and vitality rate of mosquitoes that were exposed to natural insecticides i.e with burned breadnut flowers and mosquito coils containing transflutrin and d-aletrin. Mosquito samples were taken from field eggs which were exposed with synthetic and natural insecticides. Mosquitoes that remainder alive after 24 hours exposure were mated and each group were put in 2 cages, each repetition were repeated 3 times. The mosquito eggs were observed until adult mosquitoes die. Then, the fecundity, fertility and vitality rate were compared. Based on our analysis, there were no differences on fecundity rate, between control and mosquitoes that were exposed to natural insecticides, but there were significant differences between the control and the synthetic insecticides. Natural insecticides do not increase the rate of fecundity but synthetic insecticides may increase the rate of fecundity and number of mosquitoes and causes the mosquito lifespan longer than the control and natural insecticide treatment.
Nadia Y. Castañeda
Full Text Available Mosquito cell derived cultures are useful tools for arbovirus isolation, identification or characterization. For studying dengue (DENV and yellow fever viruses (YFV Aedes albopictus C6/36 or Aedes pseudoscutellaris AP-61 cell lines, are normally used. The Aedes aegypti AEGY-28 cell line was obtained from embryonic tissues and characterized previously by one of us. In order to evaluate its susceptibility to two Flavivirus, AEGY- 28 cells were inoculated with different multiplicity of infection (MOI with type 2 DENV (COL-789, MOI: 1 and 5 and YFV clinical isolates (V-341, MOI 0,02 then processed at different times post infection (p.i.. Immunostai ning and fluorometric cell-ELISA were carried out to identify and quantify viral antigens. C6/36 and Vero cells were used as positive controls. Unexpectedly, immunoreactivity was not found in inoculated AEGY-28 cells, even in higher MOI or late times p.i., therefore antigen quantification using fluorometric cell-ELISA were not plausible. Reverse transcriptase PCR with specific primers did not detect viral RNA in AEGY-28 inoculated cells. We can conclude that Aedes aegypti AEGY-28 cell line is not susceptible to dengue and yellow fever Flavivirus, a finding possibly related with the lacking of specific molecules at the plasma membrane or absence of cell machinery necessary for viral replication.
Paily, K P; Hoti, S L; Balaraman, K
The efficiency of laboratory colonies of mosquitoes such as Anopheles stephensi Liston, Aedes aegypti (L.) Liverpool strain, Ae. aegypti wild type, Aedes albopictus (Skuse), Culex tritaeniorhynchus Giles, Culex sitiens Wiedemann, and Armigeres subalbatus Coquillett in supporting the development of Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae) microfilariae to infective larvae was investigated. The mosquitoes were fed on heparinized microfilaremic human blood by using a membrane-feeding unit with Parafilm as membrane. The rate of infection, parasite development, and parasite burden were compared with that in the known vector mosquito Culex quinquefasciatus Say. Cx. quinquefasciatus showed the highest percentage of infection, followed by Ae. aegypti Liverpool strain and An. stephensi. The rate of development of the parasite was more or less similar in all the three species, and infective larvae were found on day 13. When the larvae were harvested on day 17, Cx. quinquefasciatus yielded the highest numbers, followed by Ae. aegypti Liverpool strain and An. stephensi. The percentage of infection was low, and the development was slow in Cx. tritaeniorhynchus compared with the other susceptible species. The parasite developed to second-stage larvae only by day 22 and to infective larvae by day 28. When 2-wk-old Cx. tritaeniorhynchus were fed on microfilaremic blood, they could develop the parasite to infective larvae by day 13 postfeeding. All other species of mosquitoes tested were found to be refractory to parasite development. It is shown that Cx. quinquefasciatus is the most suitable mosquito host for the production of infective larvae. However, Ae. aegypti Liverpool strain, which is commonly used for Brugia malayi filarial parasite, also can be used for generation of W. bancrofti infective larvae to circumvent the problem of maintaining two mosquito species.
Chordas, Stephen W.; Hudson, Patrick L.; Chapman, Eric G.
The dipteran fauna of Arkansas is generally poorly known. A previous study of the Aquatic macroinvertebrates of the White River National Wildlife Refuge, the largest refuge in Arkansas, reported only 12 diptera taxa out of 219 taxa collected (Chordas et al., 1996). Most of the dipterans from this study were identified only to the family level. The family Chironomidae is a large, diverse group and was predicted to be much more diverse in the refuge than indicated by previous studies. In this study, Chironomidae were targeted, with other aquatic or semiaquatic dipterans also retained, in collections designed to better define the dipteran fauna of the White River National Wildlife Refuge. Adult dipterans were collected from 22 sites within the refuge using sweep-nets, two types of blacklight traps, and lighted fan traps in June of 2001. Specimens from previous studies were retrieved and identified to the lowest possible taxonomic level. A total of 4,917 specimens representing 122 taxa was collected. The 122 taxa were comprised of the following: two chaoborids, 83 chironomids, 15 culicids, nine tabanids, and 13 tipulids. Of these, 46 species are new state records for Arkansas. Nine undescribed species of chironomids were collected, and eight species records represent significant range extensions.
Genetic Characterization of Spondweni and Zika Viruses and Susceptibility of Geographically Distinct Strains of Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus (Diptera: Culicidae) to Spondweni Virus
301 policy or position of the U.S. Department of Defense, the Department of the Army, 302 Centers for Disease Control and Prevention, or the Kingdom...Aedes albopicutus (Thailand) 12 0 (0.0) 0 (0.0) Aedes albopicutus ( Venezuela ) 3 0 (0.0) 0 (0.0) Culex quinquefaciatus (Galveston, USA) 24 0 (0.0...albopicutus ( Venezuela ) 24 0 (0.0) 0 (0.0) Culex quinquefaciatus (Galveston, USA) 24 0 (0.0) 0 (0.0) 550 551 552 553 554 555 556 557
Full Text Available Anopheles aquasalis es considerado como el principal vector de malaria humana en el norte de Venezuela. El estudio longitudinal se llevó a cabo en áreas costeras de la Península de Paria, estado Sucre. El hábitat de las larvas de A. aquasalis fue clasificado como: manglar salobre y pantano herbáceo. Muestreos para recolectar larvas de mosquitos e insectos asociados se realizaron mensualmente en ambos criaderos desde enero hasta diciembre de 1999 (30 muestras. Simultáneamente se midieron cinco variables seleccionadas del agua: conductividad, salinidad, oxígeno disuelto, temperatura y pH. En ambos criaderos de determinaron las variaciones estacionales y temporales de las larvas de A. aquasalis e insectos acuáticos. Para el período de estudio, la abundancia de larvas fue mayor en el manglar. El análisis de correspondencia mostró una fuerte relación entre algunos factores químicos del agua y la abundancia de las larvas. La abundancia de las larvas de A. aquasalis en ambas épocas, se correlacionó positivamente con la salinidad del agua, pH y conductividad, y negativamente con el oxígeno disuelto, en la estación seca. La presencia de larvas se correlacionó positivamente con la presencia de Avicennia germinans. En el manglar existió una asociación positiva entre la abundancia de larvas y la abundancia de la familia Scirtidae y una correlación negativa entre la abundancia de larvas y la precipitación mensual (Spearman, así como una correlación negativa significativa entre la abundancia de Gerridae y la precipitación mensual. En el pantano herbáceo, no había asociaciones significativas entre la abundancia de las larvas de A. aquasalis y la abundancia de otros insectos acuáticos asociados al hábitat.Larval seasonality of the mosquito Anopheles aquasalis (Diptera: Culicidae and other insects associated to its habitat in Sucre, Venezuela. Anopheles aquasalis Curry is considered the main vector of human malaria in Northern
María V Micieli
Full Text Available Se realizó un estudio de la variación estacional de una población de estadios inmaduros de A. aegypti en La Plata, Argentina, durante cuatro años. Se colocaron 36 recipientes plásticos con 700 ml de agua declorinada y se agregó, en cada uno, una tira de papel de filtro rodeando el perímetro interno como sitio para la ovipostura. Los huevos, larvas y pupas se cuantificaron semanalmente desde septiembre de 1996 hasta agosto de 2000. Tras cuantificar el número de huevos, los papeles fueron sumergidos en cada recipiente para facilitar la eclosión y se agregó un nuevo papel. La presencia de estados inmaduros de A. aegypti fue registrada desde diciembre-enero hasta junio durante los cuatro años de estudio. En 1997 se registraron 13 105 huevos, 7 978 larvas y 1 476 pupas con un 54.7 % de recipientes positivos; en 1998, 8 194 huevos, 668 larvas y 142 pupas y un 28.3 % de recipientes positivos para este mosquito. En 1999 se obtuvieron 13 510 huevos, 3 690 larvas y 743 pupas y un 56.7 % de recipientes con A. aegypti. Para el año 2000 se registraron 16 327 huevos, 4 669 larvas y 715 pupas y un porcentaje de recipientes positivos de 59.3 %. El número de huevos y el porcentaje de eclosión se redujo drásticamente en 1998 donde las temperaturas durante el período diciembre-mayo fueron entre uno y 2.5 ºC más bajas que durante los otros tres años de estudio. Estas temperaturas menores fueron consecuencia del fenómeno climático corriente El Niño.Population dynamics of the immature stages of Aedes aegypti (Diptera: Culicidae, vector of dengue: a longitudinal study (1996-2000. A four year study was conducted on a natural population of immature stages of Aedes aegypti after the re-invasion of Argentina by this vector in 1987. Thirty six plastic containers with 700 ml of dechlorinated water were placed in the La Plata Zoological Garden, La Plata, Argentina. A strip of filter paper around each container was added to facilitate egg counting. Eggs
Melandri, Vanessa; Alencar, Jerônimo; Guimarães, Anthony Érico
Bioecological aspects of anophelines (Diptera: Culicidae) near areas under the direct influence of the hydroelectric plant reservoir of Serra da Mesa in Goiás, Brazil, were analyzed. Samples were collected at the surrounding dam area during the phases before and after reservoir impoundment. The influence of climatic and environmental factors on the occurrence of Anopheles darlingi, Anopheles albitarsis, Anopheles triannulatus, Anopheles oswaldoi and Anopheles evansae was assessed using Pearson's correlations with indicators for richness and diversity as well as the index of species abundance (ISA) and the standardized index of species abundance (SISA). The highest anopheline density occurred during the phase after filling the tank; however, no direct correlation with the climatic factors was observed during this stage. The reservoir formation determined the incidence of the anopheline species. An. darlingi was the predominant species (SISA = 1.00). The significant difference (p < 0.05) observed between the species incidence during the different reservoir phases demonstrates the environmental effect of the reservoir on anophelines.
Spatial clustering and longitudinal variation of Anopheles darlingi (Diptera: Culicidae) larvae in a river of the Amazon: the importance of the forest fringe and of obstructions to flow in frontier malaria.
Barros, F S M; Arruda, M E; Gurgel, H C; Honório, N A
Deforestation has been linked to a rise in malaria prevalence. In this paper, we studied longitudinally 20 spots, including forested and deforested portions of a temporary river in a malarigenous frontier zone. Larval habitat parameters influencing distribution of Anopheles darlingi (Diptera: Culicidae) larvae were studied. We observed that larvae were clustered in forested-deforested transitions. For the first time in the literature, it was verified that parameters determining larval distribution varied from deforested to forested areas. The proximity to human dwellings was also a significant factor determining distribution, but larvae was most importantly associated with a previously undescribed parameter, the presence of small obstructions to river flow, such as tree trunks within the river channel, which caused pooling of water during the dry season ('microdams'). In deforested areas, the most important factor determining distribution of larvae was shade (reduced luminance). Larvae were absent in the entire studied area during the wet season and present in most sites during the dry season. During the wet-dry transition, larvae were found sooner in areas with microdams, than in other areas, suggesting that flow obstruction prolongs the breeding season of An. darlingi. Adult mosquito densities and malaria incidence were higher during the dry season. Our data correlate well with the published literature, including the distribution of malaria cases near the forest fringes, and has permitted the creation of a model of An. darlingi breeding, where preference for sites with reduced luminance, human presence and microdams would interact to determine larval distribution.
Ecological characterisation and infection of Anophelines (Diptera: Culicidae) of the Atlantic Forest in the southeast of Brazil over a 10 year period: has the behaviour of the autochthonous malaria vector changed?
Buery, Julyana Cerqueira; Rezende, Helder Ricas; Natal, Licia; Silva, Leonardo Santana da; Menezes, Regiane Maria Tironi de; Fux, Blima; Malafronte, Rosely Dos Santos; Falqueto, Aloisio; Cerutti Junior, Crispim
BACKGROUND In southeastern Brazil, autochthonous cases of malaria can be found near Atlantic Forest fragments. Because the transmission cycle has not been completely clarified, the behaviour of the possible vectors in those regions must be observed. A study concerning the entomological aspects and natural infection of anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espírito Santo state was performed in 2004 and 2005. Similarly, between 2014 and 2015, 12 monthly collections were performed at the same area of the study mentioned above. METHODS Center for Disease Control (CDC) light traps with CO2 were set in open areas, at the edge and inside of the forest (canopy and ground), whereas Shannon traps were set on the edge. FINDINGS A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most frequently captured species in the CDC traps set in the forest canopy, as well as being the vector with the highest prevalence of Plasmodium vivax/simium infection, according to molecular polymerase chain reaction techniques. CONCLUSIONS P. vivax/simium was found only in abdomens of the mosquitoes of the subgenus Nyssorhynchus, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.
Brustolin, M; Talavera, S; Santamaría, C; Rivas, R; Pujol, N; Aranda, C; Marquès, E; Valle, M; Verdún, M; Pagès, N; Busquets, N
The emerging disease West Nile fever is caused by West Nile virus (WNV), one of the most widespread arboviruses. This study represents the first test of the vectorial competence of European Culex pipiens Linnaeus 1758 and Stegomyia albopicta (= Aedes albopictus) (both: Diptera: Culicidae) populations for lineage 1 and 2 WNV isolated in Europe. Culex pipiens and S. albopicta populations were susceptible to WNV infection, had disseminated infection, and were capable of transmitting both WNV lineages. This is the first WNV competence assay to maintain mosquito specimens under environmental conditions mimicking the field (day/night) conditions associated with the period of maximum expected WNV activity. The importance of environmental conditions is discussed and the issue of how previous experiments conducted in fixed high temperatures may have overestimated WNV vector competence results with respect to natural environmental conditions is analysed. The information presented should be useful to policymakers and public health authorities for establishing effective WNV surveillance and vector control programmes. This would improve preparedness to prevent future outbreaks. © 2016 The Authors. Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society.
Maiduguri, Nigeria, were studied between January and June 2002. Dipteran samples were collected every 2 weeks from five different stations. Five groups of diptera organisms simulidae, chironomidae, centrapogo nidae, culicidae and chaoboridae were found in analyzable numbers. The diptera assemblage was ...
Alfonso Arturo Miranda H
Full Text Available La primera línea celular de Aedes aegypti fue establecida por Grace en 1966 y desde entonces se han utilizado para el estudio de virus, bacterias y parásitos. En el presente trabajo se describen, por primera vez, algunas características citoquímicas de los cultivos celulares de A. aegypti, infectados con la cepa (MHOM/CO/87CL412 de Leishmania panamensis. También se realizó un estudio morfológico de las células del cultivo. Se observaron 30 células pequeñas con apariencia fibrolastoide de 10.84±2.54 µm de largo y 5.31±1.26 µm de ancho; otras 30 presentaron apariencia epitelioide con 23.04±4.00 µm de largo y 13.96±3.70 µm de ancho; éstas últimas predominaron sobre las de apariencia fibroblastoide. De 113 células, un 7.08%, presentaron abundantes gránulos citoplasmáticos positivos con la coloración de PAS, indicando presencia de polisacáridos. La prueba de peroxidasa dio un resultado negativo. El mayor porcentaje de infección (18.90%, de un total de 101 células, se presentó el día 6. Ultraestructuralmente, las células presentaron un citoplasma con aspecto vacuolado; algunas contenían parásitos, otras material fibrilar y otras estaban vacías. Los resultados indican que los cultivos celulares de A. aegypti pueden ser infectados por L. panamensis y mantener dicho proceso por aproximadamente una semana.Morphology and cytochemistry of Aedes aegypti’s cell cultures (Diptera: Culicidae and susceptibility to Leishmania panamensis (Kinetoplastida: Trypanosomatidae. The first cellular line of Aedes aegypti was developed by Grace in 1966; afterwards, other cellular lines of this species have been generated. These have been used for the study of pathogenic organisms like viruses, bacteria and parasites, which demonstrates their importance in biomedical applications. This research describes, for the first time, some cytochemical characteristics of A. aegypti cell cultures, that were infected with (MHOM/CO/87CL412 strain of
Silva Heloisa Helena Garcia da
Full Text Available Estudou-se a influência do período de quiescência dos ovos no ciclo de vida de Aedes aegypti (Linnaeus, 1762 (Diptera, Culicidae em condições de laboratório, na busca de informações que possam melhorar o direcionamento das ações de controle, pois sabe-se que o ovo é a forma mais resistente do ciclo biológico, possibilitando ao mosquito ampla sobrevida, devido à resistência às adversidades climáticas. Os experimentos foram realizados numa câmara biológica, mantida à temperatura de 28 ± 1oC, com umidade relativa de 80 ± 5% e fotofase de 12 horas. Apresentam-se os dados da influência de diferentes períodos de quiescência sobre a eclosão das larvas, desenvolvimento larval e pupal, ciclo evolutivo. Verificou-se o efeito altamente significativo do período de quiescência na eclosão das larvas. O período de quiescência não influenciou nas durações dos períodos de incubação, larval e pupal. Constatou-se que ovos de um mesmo período de quiescência apresentaram períodos de incubação estatisticamente diferentes entre si. As larvas eclodiam em grupos, definidos pela incubação, e este efeito de grupo foi significativo na duração do ciclo. Pode-se afirmar que, em 99,8% dos ciclos, a variação foi determinada pela incubação.
Culicidae (Insecta: Diptera em área de Floresta Atlântica, no Estado do Paraná, Brasil - DOI: 10.4025/actascibiolsci.v30i1.1411 Culicidae (Insecta: Diptera in areas of Atlantic Forest, Paraná State, Brazil - DOI: 10.4025/actascibiolsci.v30i1.1411
Mario Antonio Navarro-Silva
Full Text Available A alteração da paisagem natural pode gerar mudanças que favorecem o desenvolvimento e proliferação de determinadas espécies de Culicidae, em detrimento de outras que se deslocam para outros locais ou são extintas. Baseando-se nestas mudanças, algumas espécies podem ser utilizadas como bioindicadores do grau de degradação ambiental. O presente estudo tem como objetivo analisar a composição e riqueza de Culicidae, em dois ambientes em área de Floresta Atlântica, e avaliar se as espécies encontradas indicam o grau de preservação dos fragmentos estudados. As coletas foram realizadas em dois ambientes, denominados Carvalho e Trilha, em área de Floresta Atlântica (Mananciais da Serra, no Estado do Paraná - Brasil, nos meses de dezembro/2002 a maio/2003, utilizando-se um aspirador elétrico manual. Foram identificadas 48 espécies de 636 espécimes de Culicidae. A composição taxonômica e riqueza das espécies de Culicidae diferenciaram-se entre os ambientes estudados, provavelmente, influenciadas pelo estado de preservação dos fragmentos florestais. Os maiores valores de riqueza observados no Carvalho, assim como o predomínio das espécies da tribo Sabethini e Kerteszia sugerem reduzida ação antrópica neste fragmento florestal. De modo contrário, a composição das espécies e os menores valores de riqueza observadas na Trilha indicam grau alto de degradação ambientalModifications in the landscape can lead to the development and proliferation of some Culicidae species, in detriment of others. As a result, some species may be forced to move to other places or become locally extinct. Based on these changes, some species can be used as bioindicators of environmental degradation. The aim of this study was to assess Culicidae composition and richness in two Atlantic Forest sites (Carvalho and Trilha; State of Paraná, Brazil, and to evaluate whether they can be used as indicators of environmental degradation of these sites
Preferência por hospedeiro e estratificação de Culicidae (Diptera em área de remanescente florestal do Parque Regional do Iguaçu, Curitiba, Paraná, Brasil Host preference and Culicidae stratification in area of degradated inside forest of Regional do Iguaçu Park, Curitiba, Paraná, Brazil
Ana Cristina Tissot
Full Text Available A investigação das populações de Culicidae em áreas de remanescentes florestais inseridas em área urbana, podem fornecer subsídios para compreensão dos processos de utilização de habitats apresentando diferentes graus de interferência antrópica. Foram investigadas espécies potencialmente zoofílicas durante o período vespertino no interior de remanescente florestal, no espaço urbano de Curitiba, Paraná. Durante o período de setembro de 2000 a junho de 2001, foram realizadas cinco coletas por estação, com auxílio de armadilhas CDC-M instaladas em dois estratos verticais, a 1,5 m do solo e na copa das árvores (6 m. Como iscas foram utilizados mamíferos Cavia porcellus (Linnaeus, 1758 (Rodentia, Cavidae e aves Nothura maculosa (Temminck, 1815 (Tinamiformes, Tinamidae em cada um dos estratos, com revezamento das iscas animais. As armadilhas foram operadas no intervalo horário das 16:00 às 20:00 h, sendo retiradas amostras a cada intervalo de 30 minutos. Em 60 horas de operação das armadilhas CDC-M, foram capturados 1.407 exemplares de Culicidae, sendo 1.143 espécies identificadas, distribuídas em nove gêneros e 13 espécies. As espécies mais freqüentes foram Mansonia(Mansonia fonsecai (Pinto, 1932 e Mansonia (Mansonia pessoai (Barreto e Coutinho, 1944, destaca-se também a ocorrência de: Ochlerotatus (Ochlerotatus scapularis (Rondani, 1848; Psorophora (Janthinosoma ferox (Humboldt, 1819 e Aedes (Stegomyia albopictus (Skuse, 1894. Na área foram detectadas a presença de espécies com graus variados de importância epidemiológica e com tendência a explorar ambientes exófilos, florestais e peridomiciliares.Parks and plazas (green areas or vegetation islands within urban areas can provide conditions for the development of populations of mosquitoes, many species of which are very adaptable to a variety of environments. The species of mosquitoes in the family Culicidae with animal hosts, in a vegetation island within an
Piovezan, Rafael; Rosa, Stéfany Larissa; Rocha, Matheus Luca; de Azevedo, Thiago Salomão; Von Zuben, Cláudio José
Because of the high adaptive capacity of mosquitoes, studies that focus on transitional environments become very important, such as those in rural areas, which are considered as bridges between wild diseases and human populations of urban areas. In this study, a survey of the existing species of mosquitoes was performed in an Atlantic Forest area of the city of Santa Bárbara d'Oeste, São Paulo state, Brazil, using traps for immatures and analyzing the frequency and distribution of these insects over the sampling months. Five mosquito species were found: Aedes albopictus (the most frequent species), Aedes aegypti, Aedes fluviatilis, Culex quinquefasciatus, and Toxorhynchites theobaldi. The 4,524 eggs collected in ovitraps showed the presence of the tribe Aedini. Aedes aegypti and Ae. albopictus were identified after larval hatching in the laboratory, with different spatial distributions: the first of which coincides with the area of greatest diversity calculated using the Simpson index, while the second does not. The association of ecological analysis of spatial diversity with simple methods of data collection enables the identification of possible epidemiological risk situations and is a strategy that may be implemented to monitor ecological processes resulting from the interaction among different species of mosquitoes. © 2013 The Society for Vector Ecology.
Murdock, C C; Olival, Kevin J; Perkins, Susan L
We collected blood-fed, snow-melt mosquitoes (Culicidae: Culiseta and Aedes) to describe the feeding patterns of potential mosquito vectors of Jamestown Canyon virus (JCV, Bunyaviridae: Orthobunyavirus). JCV is an arthropod-borne, zoonotic virus with deer as the primary amplifying host in western alpine ecosystems. We collected mosquitoes from natural resting areas, fiber pots, and carbon-dioxide baited miniature light traps in the Colorado Rocky Mountains in 2007. We conducted two polymerase chain reactions to amplify and sequence vertebrate DNA extracted from blood-fed mosquitoes, which yielded comparable, but not identical, results. Mammal-specific primers found mule deer (Odocoileus hemionus) and elk (Cervus elaphus canadensis) as the source of all bloodmeals. To determine if unamplified bloodmeals were from nonmammalian sources, we screened all samples with conserved vertebrate primers, which confirmed the initial polymerase chain reaction results, but also found porcupine (Erethizon dorsatum) and human (Homo sapiens) as additional bloodmeal sources. We consistently found that mule deer were the primary hosts for mosquitoes in this system. These results suggest that snow-melt mosquitoes, in particular A. cataphylla, may be important vectors in western JCV alpine systems and may also act as a bridge vector for JCV from cervid virus reservoirs to humans.
Hernández-Triana, Luis Miguel; Brugman, Victor Albert; Prosser, Sean Williams John; Weland, Chris; Nikolova, Nadya; Thorne, Leigh; Marco, Mar Fernández DE; Fooks, Anthony Richard; Johnson, Nicholas
Thirty-four species of Culicidae are present in the UK, of which 15 have been implicated as potential vectors of arthropod-borne viruses such as West Nile virus. Identification of mosquito feeding preferences is paramount to the understanding of vector-host-pathogen interactions which, in turn, would assist in the control of disease outbreaks. Results are presented on the application of DNA barcoding for vertebrate species identification in blood-fed female mosquitoes in rural locations. Blood-fed females (n = 134) were collected in southern England from rural sites and identified based on morphological criteria. Blood meals from 59 specimens (44%) were identified as feeding on eight hosts: European rabbit, cow, human, barn swallow, dog, great tit, magpie and blackbird. Analysis of the cytochrome c oxidase subunit I mtDNA barcoding region and the internal transcribed spacer 2 rDNA region of the specimens morphologically identified as Anopheles maculipennis s.l. revealed the presence of An. atroparvus and An. messeae. A similar analysis of specimens morphologically identified as Culex pipiens/Cx. torrentium showed all specimens to be Cx. pipiens (typical form). This study demonstrates the importance of using molecular techniques to support species-level identification in blood-fed mosquitoes to maximize the information obtained in studies investigating host feeding patterns.
Fouad; El-Akhal; Abdelhakim; El; Ouali; Lalami; Yassine; Ez; Zoubi; Hassane; Greche; Raja; Guemmouh
Objective:To evaluate the larvicidal activity of essential oil of Origanum mtijoruna（Lamiaceae）cultivated in Morocco against Culex pipiens（Diptera:Culicidae）.Methods:The analysis and the identification of the various constituents of essential oil were carried out by gas chromatography coupled with mass spectrometry.Biological test was performed according to a standard methodology inspired by the World Health Organization protocol with slight modification.Results:This oil mainly consisted of monoterpene and sesquiterpenes.The majority compounds are 4-terpinene（28.96%）,y-terpinene（18.57%）,α-terpinene（12.72%） and sabinene（8.02%）.The lethal concentrations(LC50 and LC90) measured for the essential oil Origanum majorana,were respectively of the order of 258.71 mg/L and 580.49 mg/L.Conclusions:The results could be useful in search for newer,safer,and more effective natural larvicidal agents.
Marcia Bicudo de Paula
Full Text Available OBJETIVO: Descrever a fauna Culicidae em área sob impacto da modificação ambiental causada pela construção de represa. MÉTODOS: Foi estudada a área onde estava sendo construída a Represa Porto Primavera no município de Presidente Epitácio, SP. As capturas dos culicídeos foram realizadas mensalmente, em seis pontos exploratórios antes do seu enchimento e em um ponto fixo, um ano antes (1997-1998 e outro depois do primeiro enchimento (1999-2000. Mosquitos adultos foram capturados com aspirador, no período matutino, e com armadilhas de Shannon e CDC, no período crepuscular vespertino. Os imaturos foram coletados por meio de conchadas nos criadouros maiores e com pipeta, nos menores. RESULTADOS: No período anterior ao enchimento da represa foram coletados 944 exemplares de culicídeos imaturos, distribuídos em dez gêneros. O total de adultos foi de 14.932, dos quais 7.031 mosquitos (em dez gêneros foram capturados nos pontos exploratórios e 7.901 espécimes, distribuídos em oito gêneros, no ponto fixo. Após a primeira etapa de enchimento da represa, o total de imaturos foi de 1.201 exemplares, distribuídos em quatro gêneros, e o total de mosquitos capturados foi de 5.912, distribuídos em nove gêneros. Houve redução populacional de espécies dos gêneros Aedes e Psorophora e aumento no número de espécimes dos gêneros Aedeomyia, Anopheles, Culex (Melanoconion, Mansonia e Uranotaenia. CONCLUSÕES: As mudanças ambientais decorrentes da construção da Represa Porto Primavera favoreceram o aumento da densidade de algumas populações de culicídeos vetores e que geram incômodo, com riscos potenciais de transmissão de patógenos para humanos.OBJECTIVE: To describe the culicidae fauna in an area impacted by environmental changes caused by the construction of a dam. METHODS: The studied area was the Porto Primavera dam construction site in Southeastern Brazil. Monthly culicidae samples were taken in six exploratory sites in
Mogren, Christina L.; Webb, Samuel M.; Walton, William E.; Trumble, John T.
The distribution and speciation of arsenic (As) were analyzed in individuals of various life stages of a midge, Chironomus riparius, and the mosquito Culex tarsalis exposed to 1000 μg/l arsenate. X-ray absorption spectroscopy (XAS) revealed that C. riparius larvae accumulate As in their midgut, with inorganic arsenate [As(V)] being the predominant form, followed by arsenite [As(III)] and an As-thiol. Reduced concentrations of As in pupal and adult stages of C. riparius indicate excretion of As between the larval and pupal stages. In adults, As was limited to the thorax, and the predominant form was an As-thiol. In Cx. tarsalis, As was not found in high enough concentrations to determine As speciation, but the element was distributed throughout the larva. In adults, As was concentrated in the thorax and eyes of adults. These results have implications for understanding the biotransformation of As and its movement from aquatic to terrestrial environments. -- Highlights: •C. riparius larvae reduced arsenate to arsenite in the midgut. •C. riparius larvae accumulated As in the midgut, with 27% as a transformed As-thiol. •C. riparius adults retained As in the thorax, with 53% as As-thiol. •Larvae of Cx. tarsalis did not have a specific site of As accumulation. •Low concentrations of As in adults suggest reduced terrestrial transfer potential. -- Arsenic accumulation and biotransformation in aquatic insects is variable, but the location and speciation of As provides insight into the detoxification mechanisms of aquatic Diptera
Abstract. The hematofagic effect caused by females belonging to some species of Culicidae on humans and animals can be directly related to pathogen transmission, allergic reactions and uneasiness. The emergence of populations resistant to chemical insecticides has fostered the use of alternative methods, mainly biological control. The trials were conducted in three effluent treatment lagoons, on larvae of Culicidae to test the efficiency and persistence of commercial products whose active principles are based on Bacillus thuringiensis israelensis Berliner and Bacillus sphaericus Neide. The products tested were Vectolex (a granulated formulation of B. sphaericus, Sphaericus (a liquid formulation of B. sphaericus and Bt-horus (a liquid formulation of B. thuringiensis. The products were applied biweekly and evaluations were conducted 0, 24, 48, 72, and 120 hours after each application. The lagoons were colonized by Culex nigripalpus Theobald (1.5%, Culex saltanensis Dyar (2.25%, and Culex quinquefasciatus Say (96.25%. Bt-horus reduced larvae by 89.06%, 83.97% and 89.96% at 24, 48 and 72 hours after product application, respectively. The granulated and the liquid formulations containing B. sphaericus reduced larvae by 98.89 % and 98.34% 24 hours after application, and by 99.79% and 99.78% after 48 hours, respectively. The products and the different formulations were effective in controlling larvae of all three Culicidae species in lagoons with high levels of organic matter, but the persistence was recorded in two and three days for products containing respectively B. sphaericus and B. thuringiensis israelensis.
Full Text Available The aim of this research was to determine larvicidal activity of the ethanol extract of Inula racemosa Hook. f. (Compositae roots against the larvae of the Culicidae mosquito Aedes albopictus and to isolate any larvicidal constituents from the extract. Based on bioactivity-guided fractionation, 11,13-dihydroisoalantolactone (1, macrophyllilactone E (2, 5α-epoxyalantolactone (3, and epoxyisoalantolactone (4 were isolated and identified as the active constituents. Compounds 1 and 2 exhibited strong larvicidal activity against the early fourth-instar larvae of A. albopictus with LC50 values of 21.86 μg/mL and 18.65 μg/mL, respectively, while the ethanol extract had a LC50 value of 25.23 μg/mL. Compounds 3 and 4 also possessed larvicidal activity against the Asian tiger mosquitoes with LC50 values of 29.37 μg/mL and 35.13 μg/mL, respectively. The results indicated that the ethanol extract of I. racemosa and the four isolated constituents have potential for use in the control of A. albopictus larvae and could be useful in the search of newer, safer, and more effective natural compounds as larvicides.
Maria da Graça Teixeira Portes
Full Text Available INTRODUÇÃO: No Brasil, a Região Amazônica é endêmica em malária. Em Santa Catarina, a malária foi eliminada na década de 80. A partir daí, ocorreram poucos casos autóctones isolados, e esporádicos. No entanto, em função da existência do vetor em seu território, da existência de extensa área endêmica no Brasil e da grande mobilidade de pessoas em áreas turísticas no estado, existe a probabilidade de reintrodução da doença. MÉTODOS: Utilizou-se os seguintes dados: Banco de Dados do Núcleo de Entomologia da Fundação Nacional de Saúde, Santa Catarina (ACCES,1997-2000; Sistema de Informação de Vigilância Epidemiológica, Secretaria de Vigilância em Saúde (Malária/SC e Sistema de Informação de Notificação e Agravo(SINAN/SC. Os mesmos foram transportados e analisados, no programa Microsoft Office Excel 2007. RESULTADOS: As coletas foram realizadas em 48 municípios, 159 localidades, sendo identificados 12.310 Culicídeos, 11.546 (93,7% Anopheles e 764 (6,2% como outros. Foram identificados três subgêneros e 13 espécies de anofelinos. CONCLUSÕES: Considerando que nos municípios pesquisados, foi identificada a presença de importantes vetores como Anopheles cruzii e Anopheles albitasis e há circulação de pessoas infectadas provenientes de áreas endêmicas, pode-se considerar que os mesmos são áreas receptivas e vulneráveis à malária. Essas espécies são suspeitas de serem responsáveis pela transmissão de malária na região, principalmente nos municípios de Gaspar, Indaial e Rodeio.INTRODUCTION: The Amazon region of Brazil is endemic for malaria. In the State of Santa Catarina, malaria was eliminated in the 1980s. Since then, a few sporadic isolated autochthonous cases have occurred. However, because malaria vectors are present within Brazilian territory and extensive endemic areas exist in this country, along with the great mobility of people in tourist areas of Santa Catarina, there is the likelihood of reintroduction of the disease. METHODS: The following data were used: the database of the Entomology Group of the National Health Foundation, Santa Catarina (ACCES, 1997-2000; the epidemiological surveillance information system of the Health Surveillance Department (Malaria/SC; and the notifiable disease information system (SINAN/SC. These data were transferred to and analyzed in the Microsoft Office Excel 2007 software. RESULTS: Collections were carried out in 48 municipalities and 159 localities, and 12,310 culicids, 11,546 anophelines (93.7% and 764 others (6.2% were identified. Three subgenera and 13 species of anophelines were identified. CONCLUSIONS: Given that in the municipalities investigated, important vectors such as Anopheles cruzii and Anopheles albitasis were found to be present, with movements of infected individuals from endemic areas, these areas can be considered to be receptive and vulnerable to malaria. These species are suspected of being responsible for malaria transmission in this region, especially in the municipalities of Gaspar, Indaial and Rodeio.
Full Text Available Aedes albopictus, a vector of Dengue and Chikungunya viruses, is a robust invasive species in both tropical and temperate environments. MicroRNAs (miRNAs regulate gene expression and biological processes including embryonic development, innate immunity and infection. While a number of miRNAs have been discovered in some mosquitoes, no comprehensive effort has been made to characterize them from different developmental stages from a single species. Systematic analysis of miRNAs in Ae. albopictus will improve our understanding of its basic biology and inform novel strategies to prevent virus transmission. Between 10-14 million Illumina sequencing reads per sample were obtained from embryos, larvae, pupae, adult males, sugar-fed and blood-fed adult females. A total of 119 miRNA genes represented by 215 miRNA or miRNA star (miRNA* sequences were identified, 15 of which are novel. Eleven, two, and two of the newly-discovered miRNA genes appear specific to Aedes, Culicinae, and Culicidae, respectively. A number of miRNAs accumulate predominantly in one or two developmental stages and the large number that showed differences in abundance following a blood meal likely are important in blood-induced mosquito biology. Gene Ontology (GO analysis of the targets of all Ae. albopictus miRNAs provides a useful starting point for the study of their functions in mosquitoes. This study is the first systematic analysis of miRNAs based on deep-sequencing of small RNA samples of all developmental stages of a mosquito species. A number of miRNAs are related to specific physiological states, most notably, pre- and post-blood feeding. The distribution of lineage-specific miRNAs is consistent with mosquito phylogeny and the presence of a number of Aedes-specific miRNAs likely reflects the divergence between the Aedes and Culex genera.
Diah Fitri Rahayu
Full Text Available ABSTRAK. Demam Berdarah Dengue (DBD adalah penyakit yang disebabkan oleh virus Dengue yangditularkan oleh nyamuk . Kabupaten Banjarnegara merupakan daerah endemis reseptif DBD. Dari tahun ketahun kasus DBD cenderung meningkat, terutama di tahun 2009 - 2010. Vektor DBD di Kabupaten Banjarnegaraadalah Ae. aegypti dan Ae. albopictus. Ae. aegypti secara makroskopis terlihat sama seperti Ae. albopictus,namun perbedaannya terletak pada morfologi kepala (mesonotum di mana Ae. aegypti memiliki gambar garisseperti kepala kecapi berbentuk dengan dua garis lengkung dan dua garis lurus putih sementara Ae. albopictushanya memiliki satu garis putih di mesonotum tersebut.Kata kunci: identifikasi, Ae. aegypti, Ae. albopictusABSTRACT. Dengue hemorrhagic fever (DHF is a disease caused by the dengue virus transmitted by mosquito.Banjarnegara district is a Dengue receptive endemic area. From year to year the Dengue cases is likely toincrease, especially in 2009 - 2010. The main vector of dengue in Banjarnegara district is Aedes aegypti andAedes albopictus. Ae. aegypti morphologically look like with Ae. albopictus, but the difference lies in the headmorphology (mesonotum where A. aegypti has a picture of the line like a lyre-shaped head with two curved linesand two white straight line while A. albopictus has only one white stripe on the mesonotum.Key words:identification, Ae. aegypti, Ae. albopictus
Jan 31, 2012 ... This study was conducted to develop sequential sampling plans to estimate larval density of Liriomyza sativae Blanchard (Diptera: Agromyzidae) at three precision levels in cucumber greenhouse. The within- greenhouse spatial patterns of larvae were aggregated. The slopes and intercepts of both Iwao's.
Full Text Available Abstract Dengue is a vector-borne disease that is estimated to affect millions of individuals each year in tropical and subtropical areas, and it is reemerging in areas that have been disease-free for relatively long periods of time. In this issue of the journal, Peng et al. report on a Dengue outbreak in a city in southern China that had been disease-free for more than two decades. The infection, which was due to serotype 1, was introduced by a traveler from South-east Asia and transmitted by Aedes albopictus, the Asian tiger mosquito. Compared to Aedes aegypti, which is the most important vector of Dengue, Ae albopictus is a less competent vector of arboviruses, and the epidemics it causes are milder. However, Ae albopictus is becoming an increasingly important vector because of its rapidly changing global distribution. In particular, the worldwide trade in second hand tires, which often contain water and are an ideal place for eggs and larvae, has been a key factor in the large-scale conquest of Ae albopictus, which easily adapts to new environments, even in a temperate climate. This expansion is creating new opportunities for viruses to circulate in new areas, becoming a common cause of epidemics in Ae aegypti-free countries, from Hawaii to Mauritius. The outbreak in China, like similar events, was mild and short-lived. Because epidemics due to Ae albopictus are milder, the replacement of Ae aegypti with the tiger mosquito could even result in public-health benefits. However, there is no solid evidence of this, and the milder course of the outbreak could be in part explained by the relatively short duration of the hot season in some affected areas. Since it is almost impossible to prevent Ae albopictus from being introduced in a country, mosquito-control measures at local level remain the most effective means of controlling arbovirus outbreaks.
Mar 19, 2014 ... Wiedemann (Diptera: Tephritidae). Flávia Queiroz de Oliveira1*, José Bruno Malaquias2, Wennia Rafaelly de Souza Figueiredo3,. Jacinto de Luna Batista4, Eduardo Barbosa Beserra1 and Robério de Oliveira4. 1Universidade Estadual da Paraíba (UEPB), campus I/Campina Grande, Bodocongó, Paraíba, ...
Control Assoc 21: 182 – 186 . 7. Servicio de Erradicación de la Malaria (SEM) , 1957 . Plan de erradi- cación de la malaria en Colombia...cat populations ( Felis catus ) in Spain, Italy, Argentina at micro - geographical level. Acta Theriol (Warsz) 43: 39 – 66 . 33. Ruiz-García M...Kimmel M , Chakravorty R , King JP , Bamshad M , Watkins WS , Jorde LB , 1998 . Signatures of population expansion in micro
Chelsea T. Smartt
Full Text Available We report a laboratory colony of Culex quinquefasciatus mosquitoes were experimentally able to salivate Zika virus (ZIKV, Flaviviridae; Flavivirus at 16 days post infection (dpi. ZIKV RNA was detected in bodies and in saliva deposited on filter paper cards with subsequent studies demonstrating the presence of live ZIKV in saliva.
Full Text Available Background: Anopheles stephensi is a sub-tropical species and has been considered as one of the most important vector of human malaria throughout the Middle East and South Asian region including the malarious areas of southern Iran. Current reports confirmed An. stephensi resistance to temephos in Oman and India. However, there is no comprehensive research on mechanisms of temephos resistance in An. stephensi in the literature. This study was designed in order to clarify the enzymatic and molecular mechanisms of temephos resistance in this species.Methods: Profile activities of α- and ß-esterases, mixed function oxidase (MFO, glutathione-S-transferase (GST, insensitive acetylcholinesterase, and para-nitrophenyl acetate (PNPA-esterase enzymes were tested for An. stephensi strain with resistance ratio of 15.82 to temephos in comparison with susceptible strain.Results: Results showed that the mean activity of α-EST, GST and AChE enzymes were classified as altered indicating metabolic mechanisms have considerable role in resistance of An. stephensi to temephos. Molecular study using PCR-RFLP method to trace the G119S mutation in ACE-1 gene showed lack of the mutation responsible for organophosphate insecticide resistance in the temephos-selected strain of An. stephensi.Conclusion: This study showed that the altered enzymes but not targets site insensitivity of ACE-1 are responsible for temephos resistance in An. stephensi in south of Iran.
de Oliveira, Caroline Dantas; Tadei, Wanderli Pedro; Abdalla, Fábio Camargo; Paolucci Pimenta, Paulo Filemon; Marinotti, Osvaldo
Anopheles darlingi is an important vector of human malaria in the Amazon. Adult females of this mosquito species require a blood meal to develop eggs, preferring humans to other blood sources. Although gonotrophic concordance has been described as the norm for An. darlingi, here we report An. darlingi female mosquitoes taking two or more blood meals within their first gonotrophic cycle. Only half of field-captured adult females fed one blood meal developed follicles to Christophers' stage V. This outcome is dependent on larval nutrition, as 88% of laboratory-raised well-nourished females completed the first gonotrophic cycle with only one blood meal, while less nourished females needed additional blood meals. Half of the field-captured blood-seeking An. darlingi females had follicles in intermediate (IIIa and IIIb) and final (V) stages of the gonotrophic cycle, supporting the conclusion that An. darlingi blood feed more than once during a gonotrophic cycle. Additionally, we observed females attempting to blood feed a second time during the same day. Additional studies of An. darlingi biting behavior are necessary to accurately estimate Plasmodium sp. entomologic inoculation rates throughout the An. darlingi vast geographical distribution. © 2012 The Society for Vector Ecology.
Tantely, Michaël Luciano; Le Goff, Gilbert; Boyer, Sébastien; Fontenille, Didier
An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species). This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species), Aedes (35 species), Anopheles (26 species), Coquillettidia (3 species), Culex (at least 50 species), Eretmapodites (4 species), Ficalbia (2 species), Hodgesia (at least one species), Lutzia (one species), Mansonia (2 species), Mimomyia (22 species), Orthopodomyia (8 species), Toxorhynchites (6 species), and Uranotaenia (73 species). Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%). Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27%) with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar. PMID:27101839
N. L. Cerqueira
Full Text Available Em quinze gêneros, cento e vinte e seis espécies de mosquitos foram constatadas no material capturado pelo Servicio de Fiebre Amarilla desde 1933 até 1942. Êste número, três vezes mais elevado do que o existente na literatura para o país, seria ainda maior se possível fôsse identificar sem o auxílio de machos inúmeras fêmeas das espécies de Culex. Tôdas as espécies estudadas apresentavam suas distribuições geográficas nos departamentos e províncias onde casos de Febre Amarela foram observados. Algumas cosiderações foram feitas em torno de espécies que não correspondiam exatamente com as descrições existentes, assim como descrições de outras foram dadas, cujos sexos opostos apenas eram conhecidos.One hundred and twenty-six species of mosquitoes, corresponding fifteen genera, have been found in material collected by the Bolivian Yellow Fever Service between 1933 and 1942. This number is three times that given for the country in existing literature and would be even largar if it were possible to identify a consierable group of Culex mosquitoes composed principally of female specimens. All species studied come from Departmetns and Provinces where cases of yellow fever have been found. Consideration has been given to certain species which do not agree exactly with existing descriptions, and supplementary descriptions have been made for the male or female of two additional species for which only description of the opposite sex had existed.
Kalan, Katja; Šušnjar, Jana; Ivović, Vladimir; Buzan, Elena
The first record of Aedes koreicus was made in the village of Lovrenc na Dravskem Polju, north-eastern part of the country. The discovery of Ae. koreicus in various continental European countries motivated us to revise samples of the collected Aedes japonicus japonicus. We found Ae. koreicus in samples from 2013, where the larvae were misidentified as Ae. j. japonicus. The species was identified morphologically and molecularly. The first discovery of Ae. koreicus advocates an urgent need for a nationwide mosquito surveillance programme.
halifaxii. In Palawan and Balabac, Philippine Islands, immatures were found in densely shaded coconut husks and in large metal lined boxes in association...areas impacted by human activities the breeding places were sunny grassy fields with some algae, ruts and puddles in roads, coconut shells in the...shade, top of oil drums in the shade, and in large packing containers. Additionally, immatures were taken from a large metal-lined box, a sunlit truck
Full Text Available Body size is a physical factor of crucial importance underlying important traits of the reproductive dynamics of both sexes in mosquitoes. Most studies on the influence of body size in mating success of dengue vectors addressed sperm transfer to females and did not consider egg production, a prerequisite for population maintenance; male body size impact on reproduction has attracted little research interest with respect to sterile insect technique. In experiments involving differently sized adults, we examined whether the body size of the mates is a source of variation in reproductive outcome in Aedes aegypti. In the absence of male partners, large females (LF showed better fecundity than small females (SF. In intraclass mating trials, egg production was much greater in largesized than smallsized pairs. There were comparable fecundities in large females mated with small males and large pairs. [SF•SM] and [SF•LM] pairs showed equivalent fecundity. Nonmating did not result in the production of viable eggs by either small or large females. We also observed that eggs produced by largesized females mated with small males had better hatching success than those from either small or large pairs. Mating between small females and large males resulted in poor egg viability.
Tantely Michaël Luciano
Full Text Available An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species. This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species, Aedes (35 species, Anopheles (26 species, Coquillettidia (3 species, Culex (at least 50 species, Eretmapodites (4 species, Ficalbia (2 species, Hodgesia (at least one species, Lutzia (one species, Mansonia (2 species, Mimomyia (22 species, Orthopodomyia (8 species, Toxorhynchites (6 species, and Uranotaenia (73 species. Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%. Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27% with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar.
Irma Fátima Agrela Da Silva
Full Text Available Mosquitoes are responsible for the transmission of various diseases that affect the health of the Venezuelan population. The increase in the incidence of malaria and the emergence of diseases such as chikungunya and Zika make it necessary to implement control measures to reduce the impact of these diseases in Venezuela. To do this, it is essential to know the aspects related to their morphology, bioecology and the characteristics that make possible the participation of mosquitoes in the transmission of these diseases. The purpose of this review is to describe these aspects.
O'Meara, G F; Gettman, A D; Evans, L F; Scheel, F D
Aedes albopictus has been found in 53 of the 67 Florida counties. The initial discoveries in 11 of these counties were made in cemeteries. At several locations, Ae. albopictus became well-established in cemeteries before appearing in nearby accumulations of waste tires. The recycling of plastic floral baskets may be aiding the spread of Ae. albopictus. Mosquitoes were commonly found in all types of flower-holding containers in cemeteries, except bronze vases. In the laboratory, most Aedes aegypti eggs laid in bronze vases hatched, but larvae subsequently died. The spread of Ae. albopictus in cemeteries seems to occur at the expense of Ae. aegypti populations. At one cemetery immature Ae. albopictus and Ae. aegypti were found in about 70% of the Aedes-positive containers at the start of a monitoring program. In subsequent collections from this site, Ae. albopictus was found in nearly all Aedes-positive containers, whereas there was a progressive decrease in containers with Ae. aegypti. This trend did not appear to be the result of any seasonal pattern because in a nearby cemetery where Ae. albopictus was absent, Ae. aegypti did not show a similar decline. Limiting flower-holding containers to those with drain holes or to bronze vases would greatly limit mosquito production.
Mosquito-borne illnesses are of great concern throughout the world, and chemical insecticides are commonly employed to decrease mosquito populations. However, the developmental insecticide pipeline for vector control has primarily been filled by repurposed agricultural products, and is hampered by t...
Estirpes de Bacillus thuringiensis efetivas contra insetos das ordens Lepidoptera, Coleoptera e Diptera Bacillus thuringiensis strains effective against insects of Lepidoptera, Coleoptera and Diptera orders
Lílian Botelho Praça
Full Text Available O objetivo deste trabalho foi selecionar entre 300 estirpes de Bacillus thuringiensis as efetivas simultaneamente contra larvas de Spodoptera frugiperda J.E. Smith e Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae, Anthonomus grandis Boheman (Coleoptera: Curculionidae, Aedes aegypti Linnaeus e Culex quinquefasciatus Say (Diptera: Culicidae. Foram selecionadas duas estirpes de B. thuringiensis, denominadas S234 e S997, que apresentaram atividade contra as três ordens de insetos. As estirpes foram caracterizadas por métodos morfológicos, bioquímicos e moleculares. As mesmas apresentaram duas proteínas principais de 130 e 65 kDa, produtos de reação em cadeia da polimerase de tamanho esperado para a detecção dos genes cry1Aa, cry1Ab, cry1Ac, cry1B e cry2 e cristais bipiramidais, cubóides e esféricos.The aim of this work was to select among 300 strains of Bacillus thuringiensis those which are simultaneously effective against larvae of Spodoptera frugiperda J.E. Smith and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae, Anthonomus grandis Boheman (Coleoptera: Curculionidae, Aedes aegypti Linnaeus and Culex quinquefasciatus Say (Diptera: Culicidae. Two strains of B. thuringiensis were selected, S234 and S997, which presented activity against those three insect orders. Both strains were characterized by morphological, biochemical and molecular methods. They have presented two main proteins with 130 and 65 kDa, polimerase chain reaction products with expected sizes for detection of the genes cry1Aa, cry1Ab, cry1Ac, cry1B and cry2 and bipiramidal, cubical and spherical crystals.
Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro
Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020-2049 and 2045-2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020-2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045-2074, when Ae. albopictus may invade large new areas. Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European countries suggest that the tiger mosquito will colonize new areas in Switzerland
Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro
Background Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. Methodology/Principal Findings We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020–2049 and 2045–2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020–2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045–2074, when Ae. albopictus may invade large new areas. Conclusions/Significance Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European
Cunze, Sarah; Kochmann, Judith; Koch, Lisa K; Klimpel, Sven
The Asian tiger mosquito Aedes albopictus, native to South East Asia, is listed as one of the worst invasive vector species worldwide. In Europe the species is currently restricted to Southern Europe, but due to the ongoing climate change, Ae. albopictus is expected to expand its potential range further northwards. In addition to modelling the habitat suitability for Ae. albopictus under current and future climatic conditions in Europe by means of the maximum entropy approach, we here focused on the drivers of the habitat suitability prediction. We explored the most limiting factors for Aedes albopictus in Europe under current and future climatic conditions, a method which has been neglected in species distribution modelling so far. Ae. albopictus is one of the best-studied mosquito species, which allowed us to evaluate the applied Maxent approach for most limiting factor mapping. We identified three key limiting factors for Ae. albopictus in Europe under current climatic conditions: winter temperature in Eastern Europe, summer temperature in Southern Europe. Model findings were in good accordance with commonly known establishment thresholds in Europe based on climate chamber experiments and derived from the geographical distribution of the species. Under future climatic conditions low winter temperature were modelled to remain the most limiting factor in Eastern Europe, whereas in Central Europe annual mean temperature and summer temperatures were modelled to be replaced by summer precipitation, respectively, as most limiting factors. Changes in the climatic conditions in terms of the identified key limiting factors will be of great relevance regarding the invasive potential of the Ae. albopictus. Thus, our results may help to understand the key drivers of the suggested range expansion under climate change and may help to improve monitoring programmes. The applied approach of investigating limiting factors has proven to yield valuable results and may also provide
Kraemer, Moritz U. G.; Sinka, Marianne E.; Duda, Kirsten A.; Mylne, Adrian; Shearer, Freya M.; Brady, Oliver J.; Messina, Jane P.; Barker, Christopher M.; Moore, Chester G.; Carvalho, Roberta G.; Coelho, Giovanini E.; van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Wint, G. R. William; Elyazar, Iqbal R. F.; Teng, Hwa-Jen; Hay, Simon I.
Aedes aegypti and Ae. albopictus are the main vectors transmitting dengue and chikungunya viruses. Despite being pathogens of global public health importance, knowledge of their vectors’ global distribution remains patchy and sparse. A global geographic database of known occurrences of Ae. aegypti and Ae. albopictus between 1960 and 2014 was compiled. Herein we present the database, which comprises occurrence data linked to point or polygon locations, derived from peer-reviewed literature and unpublished studies including national entomological surveys and expert networks. We describe all data collection processes, as well as geo-positioning methods, database management and quality-control procedures. This is the first comprehensive global database of Ae. aegypti and Ae. albopictus occurrence, consisting of 19,930 and 22,137 geo-positioned occurrence records respectively. Both datasets can be used for a variety of mapping and spatial analyses of the vectors and, by inference, the diseases they transmit.
Čabanová, V.; Miterpáková, M.; Valentová, D.; Blažejová, Hana; Rudolf, Ivo; Stloukal, E.; Hurníková, Z.; Dzidová, M.
Roč. 11, č. 1 (2018), č. článku 261. ISSN 1756-3305 Institutional support: RVO:68081766 Keywords : Culex pipiens complex * West Nile virus * Diptera Culicidae * Anopheles hyrcanus * Dirofilaria immitis * Aedes albopictus * endemic area * 1st record * Slovakia * vector * Dirofilaria * mosquito-borne diseases * Anopheles maculipennis complex * xenomonitoring Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.080, year: 2016
TRUCK-MOUNTED AREA-WIDE APPLICATION OF PYRIPROXYFEN TARGETING AEDES AEGYPTI AND AEDES ALBOPICTUS IN NORTHEAST FLORIDA1 CARL W. DOUD,2,3 ANTHONY M...truck-mounted ultra-low volume applications of pyriproxyfen against Aedes aegypti larvae in artificial water containers and wild adult Ae. albopictus...larval control, Aedes aegypti, Aedes albopictus INTRODUCTION Aedes albopictus (Skuse) (Asian tiger mosquito) and Ae. aegypti (L.) (yellow fever
Iván Darío Vélez
Full Text Available La especie Aedes albopictus es un eficiente vector del dengue en Asia y, posiblemente, de otros arbovirus incluyendo la fiebre amarilla y la encefalitis. En la ultima década se ha extendido la distribución de A. albopictus a las Américas. En la ciudad de Tabatinga, Brasil, muy cerceide la frontera con Colombia, se ha informado la presencia de esta especie en 1996 y, posteriormente, en octubre de 1997. En marzo de 1998, en desarrollo de un e&udio sobre enfermedades tropicales realizado por el Programa de Estudio y Cotítrol de Enfermedades Tropicales, PECET, de la Universidad de Antioquia y la secretaría de Salud del Amazonas, se capturaron 8 ejemplares adultos de A. albopictus en la ciudad de Leticia, departamento del Amazonas, siendo éste el primer hallazgo de esta especie en Colombia. La presencia en Colombia de A. albopictus vuelve más complejo el problema del dengue por la mayor adaptación de este vector a climas más fríos, la capacidad de transmisión transovariana, la buena capacidad vectorial para transmitir los cuatro serotipos del virus y la mayor dificultad para su control dado que sus criaderos están en áreas peridomésticas y rurales. La distribución de esta especie tanto en zonas selváticas como rurales y urbanas presenta un peligro potencial de urbanizar la transmisión de la fiebre amarilla. Se presenta el plan de contingencia que se debe implementar por parte de la Secretaría de Salud del Amazonas con miras a evitar la propagación de este vector a otras regiones del país.
Schaffner, Francis; Van Bortel, Wim; Coosemans, Marc
The 1st record of Aedes albopictus in Belgium was made in a village in Oost-Vlaanderen Province. Two preimaginal stages were collected on October 31, 2000, in the used tire stock of a recycling company that imports tires from the USA and Japan. The species has reproduced on site, and local environmental conditions make its establishment possible. Anopheles plumbeus was a common companion species found in tires in high densities.
Gustavo C. Rossi
Full Text Available Se presentan 21 nuevos registros de especies y se amplía la distribución de otras 12 especies de los géneros Anopheles Meigen, Coquillettidia Dyar, Culex L., Haemagogus Williston, Ochlerotatus Lynch Arribalzaga, Onirion Harbach y Peyton, Orthopodomyia Theobald, Psorophora Robineau-Desvoidy, Sabethes Robineau-Desvoidy, Stegomyia Theobald, Toxorhynchites Theobald. Se incluyen comentarios y cambios de estatus para especies de Howardina Theobald, Ochlerotatus y Lutzia (Theobald. Actualmente, en la Argentina se hallan presentes 226 especies distribuidas en 23 géneros.Twenty one new records and 12 new distributional records of species of the genus Anopheles Meigen, Coquillettidia Dyar, Culex L., Haemagogus Williston, Ochlerotatus Lynch Arribalzaga, Onirion Harbach & Peyton, Orthopodomyia Theobald, Psorophora Robineau-Desvoidy, Sabethes Robineau-Desvoidy, Stegomyia Theobald, Toxorhynchites Theobald are reported. Comments and changes in the status of species of Howardina Theobald, Ochelrotatus and Lutzia Theobald are included. Currently, in Argentina are present 226 species distributed in 23 genera.
Maria Goreti Rosa-Freitas
Full Text Available Anopheles (Nyssorhynchus deaneorum sp. n. is described from specimens collected in Guajará-Mirim, Rondônia state and Rio Branco, Acre state, Brazil, on human and animal baits, inside dwellings and from the progenies of engorged females. A detailed description of the shape of egg, external appearance of adult female and male, genitalias, female cibarial armature and complete chaetotaxy of pupa and larva show that it can be distinguished from Anopheles albitarsis from the type-locality and other areas by the paler general external appearance of the adult, the posterolateral tufts of scales, on the female abdominal terga and the branching of the outer anterior clypeal seta (3-C of the fourth instar larva (as shown in illustrations. If species can also be distinguished from An. albitarsis from the type locality by the allele frequencies at 11 enzymic loci as represented by Nei's Genetic Distance.Anopheles (Nyssorhynchus deaneorum sp. n. é descrito a partir de exemplares coletados em capturas comparativas no intradomicílio e no peridomicílio usando isca humana e animal e progênies de fêmeas ingurgitadas, em Guarajá-Mirim, Rondônia e Rio Branco, Acre. A descrição detalhada do ovo, dos adultos fêmea e macho, inclusive cibário da fêmea, genitália, quetotaxia da pupa e da larva e seu perfil isoenzimático, mostram que esse mosquito pode ser distinguido do Anopheles albitarsis na fase adulta pelo aspecto geral mais claro, pela presença de tufos laterais de escamas escuras somente a partir do quarto ou quinto tergitos abdominais, enquanto em albitarsis começam no terceiro e, na fase larvária, pela ramificação das cerdas clipeais anteriores externas, que em albitarsis são aciculadas (como mostram as ilustrações, bem como pelo padrão isoenzimático.
Walter R. Almirón
Full Text Available Con el propósito de estudiar la preferencia de hospedadores vertebrados por mosquitos hembras, durante 2 períodos octubre-abril (primavera-verano, se realizaron muestreos cada 15 días en Córdoba y Cosquín (Argentina. Se utilizaron trampas de latón con cebo animal: anfibios (sapos, aves (pollos, mamíferos (conejos y reptiles (tortugas. El 92,9% de los especímenes recolectados pertenecen al género Culex, mientras que un 7,0% corresponde a Aedes y el 0,02% restante a Psorophora ciliata, única especie que se capturó de ese género. En trampas con pollo se recolectó el mayor número de hembras (68,7%, siguiendo en orden las trampas con conejos (29,9%, con tortugas (0,8% y con sapos (0,5%, por lo tanto, la mayoría de los mosquitos entraron en las trampas con hospedadores homeotermos. Culex dolosus se alimentó sobre todos los cebos, mientras que Cx. acharistus, Cx. chidesteri y Cx. quinquefasciatus se alimentaron sobre pollos, conejos y tortugas; Ae. albifasciatus, Ae. scapularis, Cx. bidens y Cx. coronator lo hicieron sobre ambos hospedadores homeotermos; Cx. apicinus, Cx. maxi, Cx. saltanensis y Cx. spinosus se alimentaron solamente sobre pollos y Ps. ciliata sobre conejos.Com o propósito de estudar a preferência de mosquitos fêmeas por hospedeiros vertebrados, realizaram-se amostragens quinzenais nas cidades de Córdoba e Cosquín (Argentina, durante o período de outubro a abril (primavera-verão, por dois anos consecutivos. Utilizaram-se armadilhas com iscas animais: anfíbios, aves, mamíferos e répteis. Dos espécimes coletados, 92,9% pertenciam ao gênero Culex, 7,0% a Aedes e 0,02% a Psorophora ciliata, única espécie coletada desse gênero. A maior proporçãoo de fêmeas (68,7% foi capturada em armadilhas iscadas com galinhas, seguindo-se em ordem as armadilhas com coelhos (29,9%, com tartarugas (0,8% e com anfíbios (0,05%. Assim, a maioria dos mosquitos foi coletada em armadilhas com hospedeiros homeotermos. Culex dolosus alimentou-se em todas as iscas, enquanto que Cx. acharistus, Cx. chidesteri e Cx. quinquefasciatus em galinhas, coelhos e tartarugas; Ae. albifasciatus, Ae. scapularis, Cx. bidens e Cx. coronator fizeram-no em ambos hospedeiros homeotermos; Cx. apicinus, Cx. maxi, Cx. saltanensis e Cx. spinosus alimentaram-se apenas em galinhas e Ps. ciliata em coelhos.In order to study the host preference of female mosquitoes, samples were taken fortnightly in Cordoba and Cosquin (Argentina, during October-April of two consecutive years. Four different vertebrates were used in baited-can traps: frogs, chickens, rabbits and turtles. The genus Culex acounted for 92.9% of the specimens collected, Aedes for 7.0% and Psorophora ciliata 0.02%. The highest proportion of females were collected in chicken traps (68.7%, followed by rabbit traps (29.9%, turtles (0.8% and frogs (0.5%, thus the majority of the mosquitoes were collected in traps with homeotermous hosts. Only Culex dolosus fed on all the hosts. Culex acharistus, Cx. chidesteri and Cx. quinquefasciatus fed on chickens, rabbits and turtles. Aedes albifasciatus, Ae. scapularis, Cx. bidens and Cx. coronator fed on both homeotermous hosts. Culex apicinus, Cx. maxi, Cx. saltanensis and Cx. spinosus fed only on chickens and Ps. ciliata only on rabbits.
Almério de Castro Gomes
Full Text Available As atividades antrópicas levadas a cabo em zona rural têm afetado o comportamento de mosquitos Culex (Culex, motivo pelo qual foi realizada investigação para observar seus abrigos naturais em área de pastagem, margem e interior de matas primitivas ou residuais. Foram escolhidas três localidades com características mesológicas diferenciadas pelo tipo de atividade humana, todas situadas na região do Vale do Ribeira, Estado de São Paulo, Brasil. As espécies mais abundantes foram Cx. mollis (28,0%, Cx. declarator (25,0%, Cx. lygrus (13,0% e Cx. coronator (9,6%. O conjunto Cx. Bidens + Cx. dolosus + Cx. chidesteri, de hábito mais urbanizado, foi capturado em número muito reduzido. Com relação aos ambientes pesquisados, a mata contribuiu com 2.281 indivíduos (71,4%, sugerindo ser local de abrigo preferido pelo grupo, exceto para Cx. quinquefasciatus. Avaliou-se o potencial de domiciliação de cada espécie e suas conseqüências para a população humana.The human activities carried out in rural zones have been affeecting the behavior of mosquitoes of the Culex (Culex subgenera, which was the reason for undertaking this investigation with a view to registering data on the natural resting places in pastures and on the edge of or within primitive and residual forest areas. Three localities with different mesological conditions, as to type of human activity, all them situated in the Ribeira Valley region of S. Paulo State, Brazil, were chosen. The species most abundantly found were Cx. mollis (28.0%, Cx. declarator (25.0%, Cx. lygrus (13.0% and Cx. coronator (9.6%. The collection of mosquitoes Cx. bidens + Cx. dolosus + Cx. chidesteri, known to be more urban, was much smaller than that of any other species of the group. With reference to outdoor environments, woodland contributed with 2,281 individuals (71.4% suggesting their preference for this resting place, except for Cx. quinquefasciatus. Results are evaluated for the determination of the potential domicilation of each species and consequence of the same for the human population.
Full Text Available Abstract. Aedes aegypti and Ae. albopictus mosquitoes being the vector of Dengue Haemorrhagic Fever (DHF. Various efJort have been done to control the mosquitoes, including using plant extract as repellent. Pandanus amaryllifolius and Notophanax scutellarium leaf were known to posses repellent activity for mosquito species. The study aimed to examine efJectiveness ofP. amaryllifolius and N. scutellarium leaf as repellent for Ae. albopictus. The result study on i-hr treatment showed that power protection of pandan leaves (N. scutellarium was 93.55%, while mangkokan leaves (p. amaryllifolius was 87.5%. Based on ANOVA analysis, there was not significantly dijJerent of power protection between N. scutellarium leafs and P. amaryllifolius leafs extracts against Ae. albopictus mosquitoes. Both of these test, plants has showed the potential to be a repellent and eliminate the emergence of Ae. albopictus mosquitoes, so it may efJectively reduce contact between host and dengue vector. Keywords: P. amaryllifolius, N. scutellarium, repellent, Ae. albopictus, dengue Abstrak. Nyamuk Aedes aegypti dan Ae. albopictus merupakan vektor dari Demam Berdarah Dengue. Pengendalian nyamuk vektor untuk memutus rantai penularan di antaranya menggunakan repelen tanaman. Daun pandan (Pandanus amaryllifolius dan mangkokan (Notophanax scutellarium adalah tanaman lokal yang mempunyai potensi sebagai repelensi nyamuk. Penelitian ini ditujukan untuk mengetahui tentang efektivitas daun F amaryllifolius dan N scutellarium sebagai bahan repelen nyamuk Ae. albopictus. Daya proteksi daun pandan (N scutellarium pada jam satu jam pertama perlakuan adalah 93,55%, sedangkan daun mangkokan (F amaryllifolius sebesar 87,5%. Hasil analisis ANOVA menunjukan bahwa daya proteksi ekstrak daun pandan dan mangkokan terhadap nyamuk Ae.albopictus berdasarkan jam perlakuan tidak berbeda nyata. Kedua tanaman uji tersebut mempunyai potensi sebagai repelen atau dapat menghalau kedatangan nyamuk Ae
Full Text Available Abstracts. Behavior of the mosquito Aedes albopictus is generally res ting outside the home with the brood in a natural or artificial containers protected from sunlight. Human biting activity between the hours of9:00 to 11:00 and between the hours of 17:00 to 18:00 inside and outside the home. The period of rest after sucking the blood 4-5 days and is ready to lie. Habitat or the environment that most coveted of th is mosquito is a forest or garden with temperatures of 24-30 0 C. eggs hatch after 4-5 days with a temperature of 24-30 0 C, the eggs usually form elus ters of 49-60 eggs Larvae and pupae usually found in containers, pieces of bambo containing water. The period of the larvae to adults between 20-25 days. The spread of Ae albopictus mosquitoes from Africa, India, Pakistan, Sri Lanka, Thailand, Malaysia, Vietnam, Papua New Guinea, northern Australia, and Indonesia. Role in disease transmission is a secondary vector or as the primary vector of dengue hemorrhagic fever. On viral diseases that attack the nerves like encephalistis Japanese, Western or Eastern encephalistis, and Chikuguya has been demonstrated by laboratories, as well as on animal diseases caused by Dirofilaria immitis agent, Plasmodium lophurae, P. gallinaceum, and P. fallax.Keyword : Aedes albopictus mosquito, bionomic, the habit of biting / looking for blood, the ability to fly
Ding, Fangyu; Fu, Jingying; Jiang, Dong; Hao, Mengmeng; Lin, Gang
Mosquito-borne infectious diseases, such as Rift Valley fever, Dengue, Chikungunya and Zika, have caused mass human death with the transnational expansion fueled by economic globalization. Simulating the distribution of the disease vectors is of great importance in formulating public health planning and disease control strategies. In the present study, we simulated the global distribution of Aedes aegypti and Aedes albopictus at a 5×5km spatial resolution with high-dimensional multidisciplinary datasets and machine learning methods Three relatively popular and robust machine learning models, including support vector machine (SVM), gradient boosting machine (GBM) and random forest (RF), were used. During the fine-tuning process based on training datasets of A. aegypti and A. albopictus, RF models achieved the highest performance with an area under the curve (AUC) of 0.973 and 0.974, respectively, followed by GBM (AUC of 0.971 and 0.972, respectively) and SVM (AUC of 0.963 and 0.964, respectively) models. The simulation difference between RF and GBM models was not statistically significant (p>0.05) based on the validation datasets, whereas statistically significant differences (p<0.05) were observed for RF and GBM simulations compared with SVM simulations. From the simulated maps derived from RF models, we observed that the distribution of A. albopictus was wider than that of A. aegypti along a latitudinal gradient. The discriminatory power of each factor in simulating the global distribution of the two species was also analyzed. Our results provided fundamental information for further study on disease transmission simulation and risk assessment. Copyright © 2017 Elsevier B.V. All rights reserved.
Blasco Rivera, Cristina
El mosquito tigre (Ae. Albopictus) es uno de los vectores de las enfermedades causadas por arbovirus, siendo actualmente, la especie vectorial más invasiva del mundo. Se introdujo en Europa en 1979 localizándose en España por primera vez en agosto de 2004 en San Cugat del Vallés en Barcelona, desde donde no ha dejado de extenderse. Es vector del virus del dengue, virus del chikungunya, virus Zika y virus de la fiebre amarilla. El objetivo principal de este Trabajo de Fin de Grado será realiza...
Joanne, Sylvia; Vythilingam, Indra; Teoh, Boon-Teong; Leong, Cherng-Shii; Tan, Kim-Kee; Wong, Meng-Li; Yugavathy, Nava; AbuBakar, Sazaly
To determine the susceptibility status of Aedes albopictus with and without Wolbachia to the four dengue virus serotypes. Two newly colonised colonies of Ae. albopictus from the wild were used for the study. One colony was naturally infected with Wolbachia while in the other Wolbachia was removed by tetracycline treatment. Both colonies were orally infected with dengue virus-infected fresh blood meal. Dengue virus load was measured using quantitative RT-PCR at four-time intervals in the salivary glands, midguts and ovaries. Wolbachia did not significantly affect Malaysian Ae. albopictus dengue infection or the dissemination rate for all four dengue virus serotypes. Malaysian Ae. albopictus had the highest replication kinetics for DENV-1 and the highest salivary gland and midgut infection rate for DENV-4. Wolbachia, which naturally exists in Malaysian Ae. albopictus, does not significantly affect dengue virus replication. Malaysian Ae. albopictus is susceptible to dengue virus infections and capable of transmitting dengue virus, especially DENV-1 and DENV-4. Removal of Wolbachia from Malaysian Ae. albopictus would not reduce their susceptibility status. © 2017 John Wiley & Sons Ltd.
Tsai, Pui-Jen; Teng, Hwa-Jen
Aedes mosquitoes in Taiwan mainly comprise Aedes albopictus and Ae. aegypti. However, the species contributing to autochthonous dengue spread and the extent at which it occurs remain unclear. Thus, in this study, we spatially analyzed real data to determine spatial features related to local dengue incidence and mosquito density, particularly that of Ae. albopictus and Ae. aegypti. We used bivariate Moran's I statistic and geographically weighted regression (GWR) spatial methods to analyze the globally spatial dependence and locally regressed relationship between (1) imported dengue incidences and Breteau indices (BIs) of Ae. albopictus, (2) imported dengue incidences and BI of Ae. aegypti, (3) autochthonous dengue incidences and BI of Ae. albopictus, (4) autochthonous dengue incidences and BI of Ae. aegypti, (5) all dengue incidences and BI of Ae. albopictus, (6) all dengue incidences and BI of Ae. aegypti, (7) BI of Ae. albopictus and human population density, and (8) BI of Ae. aegypti and human population density in 348 townships in Taiwan. In the GWR models, regression coefficients of spatially regressed relationships between the incidence of autochthonous dengue and vector density of Ae. aegypti were significant and positive in most townships in Taiwan. However, Ae. albopictus had significant but negative regression coefficients in clusters of dengue epidemics. In the global bivariate Moran's index, spatial dependence between the incidence of autochthonous dengue and vector density of Ae. aegypti was significant and exhibited positive correlation in Taiwan (bivariate Moran's index = 0.51). However, Ae. albopictus exhibited positively significant but low correlation (bivariate Moran's index = 0.06). Similar results were observed in the two spatial methods between all dengue incidences and Aedes mosquitoes (Ae. aegypti and Ae. albopictus). The regression coefficients of spatially regressed relationships between imported dengue cases and Aedes mosquitoes
Full Text Available Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecticidestherefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to suppressmosquito larval population.Methods: WHO recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used.Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis wasthe best in terms of LC50 (297 ppm, % mortality (97% and LT50 (18.49 hours then freutrall early (Citrus reticulatewith LC50 (377.4 ppm, % mortality (88% and LT50 (31 hours, While nomilin gave lowest LC50 (121.04 ppm than limonin (382.22 ppm after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 μg/ml and 21.19 μg/ml than freutrall early (5.29 μg/ml and 3.89 μg/ml respectively.Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required.
Liu, Zhuanzhuan; Zhou, Tengfei; Lai, Zetian; Zhang, Zhenhong; Jia, Zhirong; Zhou, Guofa; Williams, Tricia; Xu, Jiabao; Gu, Jinbao; Zhou, Xiaohong; Lin, Lifeng; Yan, Guiyun
In China, the prevention and control of Zika virus disease has been a public health threat since the first imported case was reported in February 2016. To determine the vector competence of potential vector mosquito species, we experimentally infected Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes and determined infection rates, dissemination rates, and transmission rates. We found the highest vector competence for the imported Zika virus in Ae. aegypti mosquitoes, some susceptibility of Ae. albopictus mosquitoes, but no transmission ability for Cx. quinquefasciatus mosquitoes. Considering that, in China, Ae. albopictus mosquitoes are widely distributed but Ae. aegypti mosquito distribution is limited, Ae. albopictus mosquitoes are a potential primary vector for Zika virus and should be targeted in vector control strategies. PMID:28430562
Dieng, Hamady; Rahman, G. M. Saifur; Abu Hassan, A.; Che Salmah, M. R.; Satho, Tomomitsu; Miake, Fumio; Boots, Michael; Sazaly, Abubakar
Larvae of Aedes albopictus Skuse typically inhabit natural and artificial containers. Since these larval habitats are replenished by rainfall, Ae. albopictus may experience increased loss of immature stages in areas with high levels of rainfall. In this study, we investigated the effects of rainfall and container water level on population density, and oviposition activity of Ae. albopictus. In field and laboratory experiments, we found that rainfall resulted in the flushing of breeding habitats. Excess rain negatively impacted larval and pupal retention, especially in small habitats. When filled with water to overflowing, container habitats were significantly repellent to ovipositing females. Taken together, these data suggest that rainfall triggers population loss of Ae. albopictus and related species through a direct detrimental effect (flushing out) and an indirect effect (ovipositional repellency).
Liu, Zhuanzhuan; Zhou, Tengfei; Lai, Zetian; Zhang, Zhenhong; Jia, Zhirong; Zhou, Guofa; Williams, Tricia; Xu, Jiabao; Gu, Jinbao; Zhou, Xiaohong; Lin, Lifeng; Yan, Guiyun; Chen, Xiao-Guang
In China, the prevention and control of Zika virus disease has been a public health threat since the first imported case was reported in February 2016. To determine the vector competence of potential vector mosquito species, we experimentally infected Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes and determined infection rates, dissemination rates, and transmission rates. We found the highest vector competence for the imported Zika virus in Ae. aegypti mosquitoes, some susceptibility of Ae. albopictus mosquitoes, but no transmission ability for Cx. quinquefasciatus mosquitoes. Considering that, in China, Ae. albopictus mosquitoes are widely distributed but Ae. aegypti mosquito distribution is limited, Ae. albopictus mosquitoes are a potential primary vector for Zika virus and should be targeted in vector control strategies.
São Thiago, André Iwersen de; Kupek, Emil; Ferreira Neto, Joaquim Alves; São Thiago, Paulo de Tarso
Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.Foi desenvolvido um programa de computador para reconhecimento da larva de Aedes aegypti e Aedes albopictus, vetores biológicos de dengue e febre amarela. O programa possibilita rá...
Di Luca, Marco; Severini, Francesco; Toma, Luciano; Boccolini, Daniela; Romi, Roberto; Remoli, Maria Elena; Sabbatucci, Michela; Rizzo, Caterina; Venturi, Giulietta; Rezza, Giovanni; Fortuna, Claudia
We report a study on vector competence of an Italian population of Aedes albopictus for Zika virus (ZIKV). Ae. albopictus was susceptible to ZIKV infection (infection rate: 10%), and the virus could disseminate and was secreted in the mosquito's saliva (dissemination rate: 29%; transmission rate: 29%) after an extrinsic incubation period of 11 days. The observed vector competence was lower than that of an Ae. aegypti colony tested in parallel.
Dieng, Hamady; Saifur, Rahman G. M.; Hassan, Ahmad Abu; Salmah, M. R. Che; Boots, Michael; Satho, Tomomitsu; Jaal, Zairi; AbuBakar, Sazaly
BACKGROUND: The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity du...
Full Text Available The dramatic global expansion of Aedes albopictus in the last three decades has increased public health concern because it is a potential vector of numerous arthropod-borne viruses (arboviruses, including the most prevalent arboviral pathogen of humans, dengue virus (DENV. Ae. aegypti is considered the primary DENV vector and has repeatedly been incriminated as a driving force in dengue's worldwide emergence. What remains unresolved is the extent to which Ae. albopictus contributes to DENV transmission and whether an improved understanding of its vector status would enhance dengue surveillance and prevention. To assess the relative public health importance of Ae. albopictus for dengue, we carried out two complementary analyses. We reviewed its role in past dengue epidemics and compared its DENV vector competence with that of Ae. aegypti. Observations from "natural experiments" indicate that, despite seemingly favorable conditions, places where Ae. albopictus predominates over Ae. aegypti have never experienced a typical explosive dengue epidemic with severe cases of the disease. Results from a meta-analysis of experimental laboratory studies reveal that although Ae. albopictus is overall more susceptible to DENV midgut infection, rates of virus dissemination from the midgut to other tissues are significantly lower in Ae. albopictus than in Ae. aegypti. For both indices of vector competence, a few generations of mosquito colonization appear to result in a relative increase of Ae. albopictus susceptibility, which may have been a confounding factor in the literature. Our results lead to the conclusion that Ae. albopictus plays a relatively minor role compared to Ae. aegypti in DENV transmission, at least in part due to differences in host preferences and reduced vector competence. Recent examples of rapid arboviral adaptation to alternative mosquito vectors, however, call for cautious extrapolation of our conclusion. Vector status is a dynamic
Waldock, Joanna; Chandra, Nastassya L; Lelieveld, Jos; Proestos, Yiannis; Michael, Edwin; Christophides, George; Parham, Paul E
Aedes albopictus is a vector of dengue and chikungunya viruses in the field, along with around 24 additional arboviruses under laboratory conditions. As an invasive mosquito species, Ae. albopictus has been expanding in geographical range over the past 20 years, although the poleward extent of mosquito populations is limited by winter temperatures. Nonetheless, population densities depend on environmental conditions and since global climate change projections indicate increasing temperatures and altered patterns of rainfall, geographic distributions of previously tropical mosquito species may change. Although mathematical models can provide explanatory insight into observed patterns of disease prevalence in terms of epidemiological and entomological processes, understanding how environmental variables affect transmission is possible only with reliable model parameterisation, which, in turn, is obtained only through a thorough understanding of the relationship between mosquito biology and environmental variables. Thus, in order to assess the impact of climate change on mosquito population distribution and regions threatened by vector-borne disease, a detailed understanding (through a synthesis of current knowledge) of the relationship between climate, mosquito biology, and disease transmission is required, but this process has not yet been undertaken for Ae. albopictus. In this review, the impact of temperature, rainfall, and relative humidity on Ae. albopictus development and survival are considered. Existing Ae. albopictus populations across Europe are mapped with current climatic conditions, considering whether estimates of climatic cutoffs for Ae. albopictus are accurate, and suggesting that environmental thresholds must be calibrated according to the scale and resolution of climate model outputs and mosquito presence data. PMID:23916332
Takumi, Katsuhisa; Scholte, Ernst-Jan; Braks, Marieta; Reusken, Chantal; Avenell, David; Medlock, Jolyon M
The Asian tiger mosquito Aedes albopictus was detected for the first time in the Netherlands in the summer of 2005. Aedes albopictus is a competent vector of several human viral diseases, and therefore the recent appearance of the vector is a concern to local public health authorities. In 2006 and 2007, the mosquito was found repeatedly and regularly at Lucky bamboo import companies. To assess whether imported Ae. albopictus could establish to produce subsequent generations in the following years or whether the winter conditions in the Netherlands would prove too cold to allow overwintering of diapausing eggs, predictions were made using a Geographic Information Systems (GIS) model based on January average temperature and the annual precipitation recorded in 2006. Seasonal activity of overwintering Ae. albopictus was estimated for temperate strains based on the weekly average temperature and weekly photoperiod using spring egg hatching thresholds of 10.5 degrees C and 11.25 hours, and egg diapause and adult survival thresholds of 9.5 degrees C and 13.5 hours. The analyses indicate that the climate conditions in the Netherlands over the past 10 years were favorable to allow overwintering of diapausing eggs of temperate strains of Ae. albopictus, particularly in the western coastal region. This region was also the area where adult Ae. albopictus were intercepted inside and surrounding plant glasshouses. The estimated number of weeks elapsing between first egg hatching in spring and the production of diapausing eggs in autumn ranged between 17 and 22 weeks in 2006.
Gao, Q; Xiong, C L; Zhou, Y B; Cao, H; Jiang, Q W
To evaluate Aedes albopictus infestation status in the central urban area of Shanghai, and analyze the related epidemic risk of mosquito-borne infectious disease. Consecutive mosquito surveillance was conducted in the green lands and residential areas in the central urban area of Shanghai during 2012-2014, the Aedes albopictus density and its seasonal fluctuation were observed; the sequence of Aedes albopictus in Shanghai was aligned with that in other epidemic area abroad, and the susceptibility of Aedes albopictus to mosquito-borne virus and endemic risk were analyzed. No Aedes aegypti was found in the central urban area of Shanghai. As predominant species in both the residential area and the green lands, the proportion of Aedes albopictus in the residential area was significantly higher than that in the green lands(78.53% vs. 19.99%, χ(2) =15 525.168, PAedes albopictus in Shanghai and Aedes albopictus in Africa was quite far. No Aedes aegypti was found in Shanghai and its surrounding areas, while Aedes albopictus infestation in the central urban area of Shanghai was serious. Strict measures should be taken to reduce the Aedes albopictus density for the effective control Zika virus spread.
Víctor Emanuel Pessoa Martins
Full Text Available Pela primeira vez é registrada a ocorrência de Aedes (Stegomyia albopictus em área urbana da cidade de Fortaleza, no Estado do Ceará, Brasil. De janeiro a julho de 2005 foram utilizadas ovitrampas para a coleta de ovos de Aedes spp., os quais foram mantidos em laboratório para desenvolvimento até a fase adulta. Os mosquitos resultantes foram identificados e submetidos a testes para o isolamento dos vírus da dengue. Foram identificados 13 espécimes de Aedes albopictus, todos fêmeas. Não foi isolado vírus da dengue em nenhum dos pools de mosquitos. Apesar de o Aedes albopictus não ter sido incriminado por surtos de dengue no Brasil, não se pode descartar a possibilidade da transmissão dos vírus da dengue por tais mosquitos.For the first time, the occurrence of Aedes (Stegomyia albopictus in an urban area of the city of Fortaleza, Northeastern, Brazil, is reported. From January to July 2005, ovitraps were used to collect eggs from Aedes spp., which were kept under laboratory conditions to develop into the adult phase. The resultant mosquitoes were identified and subjected to dengue virus isolation tests. Thirteen specimens of Aedes albopictus, all females, were identified. No dengue virus was isolated in any of the mosquito pools. Even though Aedes albopictus has not been incriminated in Brazilian dengue outbreaks, the possibility of dengue virus transmission by these mosquitoes cannot be dismissed.
Thomas Anung Basuki
Full Text Available We present a methodology for modelling population dynamics with formal means of computer science. This allows unambiguous description of systems and application of analysis tools such as simulators and model checkers. In particular, the dynamics of a population of Aedes albopictus (a species of mosquito and its modelling with the Stochastic Calculus of Looping Sequences (Stochastic CLS are considered. The use of Stochastic CLS to model population dynamics requires an extension which allows environmental events (such as changes in the temperature and rainfalls to be taken into account. A simulator for the constructed model is developed via translation into the specification language Maude, and used to compare the dynamics obtained from the model with real data.
Full Text Available Field studies were conducted to determine the mosquito species richness in the urban area of Greater Puntarenas in Costa Rica. Two cross-sectional entomological surveys were performed in seven localities of Puntarenas: one survey was performed during the wet season and the other during the dry season. The sections evaluated were determined by applying a stratified cluster sampling method using satellite imagery, and a sample of 26 cells (100x100m was selected for the study. The number of cells per locality was proportional to the area of each locality. The presence of mosquito larvae and pupae in water-filled artificial and natural containers was determined in each cell. Infestation was expressed as a diversity index per type of container (Ii. Eight types of larvae were identified (Aedes aegypti, Culex quinquefasciatus, Culex interrogator, Culex nigripalpus, Culex corniger, Culex tarsalis, Limatus durhamii and Toxorhynchites theobaldi and in two cases it was only possible to identify the genus (Culex sp. and Uranotaenia sp.. A. aegypti was the most common species followed by C. quinquefascitus. Diversity of wet environments can explain the co-occurrence of various culicid species in some localities. Although A. aegypti is the only documented disease vector in the area, C quinquefasciatus, C. nigripalpus, and the other species of Culex could be considered potential vectors of other pathogens. The presence and ecology of all mosquito species should be studied to optimize surveillance and prevention of dengue and to prevent the emergence of other mosquito-transmitted diseases. Rev. Biol. Trop. 57 (4: 1223-1234. Epub 2009 December 01.La riqueza de especies de mosquitos urbanos de la Gran Puntarenas (Puntarenas, Costa Rica fue evaluada por medio de análisis larvales. Dos encuestas entomológicas fueron realizadas en siete localidades de la Gran Puntarenas durante un año. Una de las encuestas fue realizada en la estación seca y la otra se llevó a cabo en la estación lluviosa. Las áreas evaluadas fueron determinadas aplicando un muestreo por conglomerados usando imágenes satelitales. Veintiséis celdas (100x100m fueron seleccionadas en las comunidades elegidas y en éstas fueron realizadas las evaluaciones entomológicas. El número de celdas por localidad fue proporcional al área de cada localidad. La presencia de larvas o pupas fue determinada en contenedores con agua (naturales y artificiales. La infestación se expresó por medio índices de diversidad por tipo de contenedor (Ii. La asociación entre contenedores positivos por especies particulares y localidades fue evaluada mediante pruebas de Chi-cuadrado (α=0.05. Ocho de los tipos de larvas encontrados fueron identificados a nivel de especie (Aedes aegypti, Culex quinquefasciatus, C. interrogator, C. nigripalpus, C. corniger, C. tarsalis, Limatus durhamii, Toxorhynchites theobaldi y dos se identificaron a nivel de género (Culex sp., y Uranotaenia sp. A aegypti fue la especie más frecuente en la Gran Puntarenas. C. quinquefasciatus fue la segunda en frecuencia. Algunas localidades como Carrizal mostraron una importante diversidad de ambientes acuáticos que promovieron la ocurrencia de diferentes especies de culícidos. La distribución de los contenedores positivos por localidad en función de las especies encontradas no mostró homogeneidad (p>0.05. Aunque A. aegypti es el único vector documentado en la zona, otros mosquitos como C. quinquefasciatus y otras especies de Culex podrían ser potenciales vectores de otros agentes etiológicos (virus del Nilo occidental, virus de la encefalitis de San Luis, virus de la encefalitis equina del este. Los resultados obtenidos indican la necesidad considerar la presencia y la ecología de todas las especies de mosquitos en las campañas preventivas por dengue en el área, y en la vigilancia epidemiológica por otras enfermedades transmitidas por mosquitos.
Gornostaeva, R M
Among females and larvae of mosquitoes collected in 1969, 1981-1984 in the area of the Sayan-Shushenskoe hydroelectric power station (140 km up the Yenisei River from the Abakan city) 5 genera and 30 species were recorded. Based on recent collections and reference data (Gornostaeva e. a., 1969; Gornostaeva, Danilov, 1986) the fauna of the region in question includes 31 species of mosquitoes (Anopheles--1, Culiseta--2, Coquillettidia--1, Aedes--22, Culex--5).
Full Text Available INTRODUCTION: Findings of immature forms of Coquillettidia venezuelensis in temporary breeding sites, without the presence of aquatic plants or other submerged plant tissue are reported. METHODS: A systematic scooping technique to collect specimens was used at the breeding site. RESULTS: Immature forms of Coquillettidia venezuelensis, Anopheles rangeli, An. evansae and Culex sp. were collected from areas of the hydroelectric power station of São Salvador, State of Goiás. CONCLUSIONS This is a novel finding relating to the bioecology of Cq. venezuelensis, a species of medical interest that has been found naturally infected with arboviruses, including Oropouche and West Nile virus.
Tejerina, Edmundo Fabricio; Almeida, Francisco Felipe Ludueña; Almirón, Walter Ricardo
Life statistics of four Aedes aegypti subpopulations from the subtropical province of Misiones were studied during autumn and winter, under semi-natural conditions, coming from the localities of Posadas (SW), San Javier (SE), Bernardo de Irigoyen (NE) and Puerto Libertad (NW). The eastern subpopulations are geographically separated by the central mountain system of the province from the western subpopulations. High percentages of larval and pupal survival (97-100%) were recorded, and no significant differences were detected among the four subpopulations. Larvae and pupae lasted approximately 8 days to complete their development, no significant differences being detected among the four subpopulations studied. Sex ratio recorded did not differ significantly from 1:1. Male longevity did not show difference among the different subpopulations, but female longevity was remarkably different among the four subpopulations (F=16.27; d.f.=(3;8); P=0.0009), ranging among 11.45 days for San Javier and 57.87 days for Posadas. Fecundity also varied considerably among subpopulations, the greatest number (307.44 eggs/female) being recorded for Posadas (F=4.13; d.f.=(3;8); P=0.04). Ae. aegypti females of the western subpopulations lived longer than the eastern subpopulations studied, therefore, the risk of dengue outbreak would be greater on the Misiones Province border with Paraguay.
Maria Anice Mureb Sallum
Full Text Available Anopheles galvaoi, a member of the subgenus Nyssorhynchus, is redescribed based on morphological characters of the adults male and female, fourth-instar larva and pupa. Female, male genitalia, larval and pupal stages are illustrated. Data about medical importance, bionomics, and distribution are given based on literature records. Adult female of An. galvaoi can be easily misidentified as An. benarrochi Gabaldón and An. aquasalis Curry. A few characters are indicated for identifying female and immatures of An. galvaoi. Phylogenetic relationships among An. galvaoi and six other species of the Oswaldoi Subgroup are estimated using COII mtDNA and ITS2 rDNA gene sequences. Lectotype of An. galvaoi, an adult female from Rio Branco, State of Acre, is invalidated.
Seidel, Bernhard; Silbermayr, Katja; Kolodziejek, Jolanta; Indra, Alexander; Nowotny, Norbert; Allerberger, Franz
On July 15, 2012, adult Anopheles hyrcanus (Pallas 1771) mosquitoes were caught next to a farm barn near Rust, Burgenland, close to Lake Neusiedl National Park in eastern Austria. Six weeks later, adults of this invasive species were also found in a sheep shelter outside the village of Oggau and another 2 weeks later, in a horse barn in Mörbisch. The morphological typing was confirmed genetically by amplification and sequencing of a 1,404-bp-long fragment within the 5.8S ribosomal RNA gene, the internal transcribed spacer 2, and the 28S ribosomal RNA gene. Out of two A. hyrcanus pools analyzed, one was found positive for Plasmodium sp. A 460-bp-long sequence within the mitochondrial cytochrome b region revealed 100 % identity to a sequence of a Plasmodium parasite identified in a New Zealand bellbird (Anthornis melanura). The Austrian finding sites are close to the Hungarian border. In Hungary, the occurrence of A. hyrcanus was already reported in 1963. A. hyrcanus is considered the most important potential vector of malaria in southern France today. In Austria, sporadic autochthonous malaria cases could emerge, caused by immigration from malaria-endemic countries and heavy tourism. However, the broad population coverage of the Austrian health care system makes the reestablishment of endemic areas for malaria unlikely.
Reegan, Appadurai Daniel; Paulraj, Michael Gabriel; Ignacimuthu, Savarimuthu
We show for the first time that the midgut of Culex quinquefasciatus (Say) mosquito larvae harbors halotolerant bacteria. The midgut from field collected Cx. quinquefasciatus larvae were dissected under aseptic conditions, homogenized and plated on LB agar medium with 2% (w/v) NaCl. Two different colonies were successfully isolated and bacterial isolates were identified by 16S rRNA sequences. The halotolerant bacterial isolates were: Halobacillus litoralis (CxH1) and Staphylococcus cohnii (CxH2). The gene sequence of these isolates has been deposited in GenBank (JN016804 and JN183986). These halotolerant bacteria grew in the absence of salt (0%) as well as in the presence of relatively high salt concentrations in culture medium (20%), and grew best in the presence of 8-10% (w/v) NaCl. H. litoralis and S. cohnii showed growth up to 18 and 20% (w/v) NaCl, respectively. Optimum growth temperatures for both the bacteria were between 30-37 degrees C. H. litoralis was resistant to the antibiotics oxacillin, penicillin, polymixin and S. cohnii was resistant to the antibiotic oxacillin.
Harry C Evans
Full Text Available Classical biological control has been used extensively for the management of exotic weeds and agricultural pests, but never for alien insect vectors of medical importance. This simple but elegant control strategy involves the introduction of coevolved natural enemies from the centre of origin of the target alien species. Aedes aegypti - the primary vector of the dengue, yellow fever and Zika flaviviruses - is just such an invasive alien in the Americas where it arrived accidentally from its West African home during the slave trade. Here, we introduce the concept of exploiting entomopathogenic fungi from Africa for the classical biological control of Ae. aegypti in the Americas. Fungal pathogens attacking arthropods are ubiquitous in tropical forests and are important components in the natural balance of arthropod populations. They can produce a range of specialised spore forms, as well as inducing a variety of bizarre behaviours in their hosts, in order to maximise infection. The fungal groups recorded as specialised pathogens of mosquito hosts worldwide are described and discussed. We opine that similar fungal pathogens will be found attacking and manipulating Ae. aegypti in African forests and that these could be employed for an economic, environmentally-safe and long-term solution to the flavivirus pandemics in the Americas.
Rosero-García, Doris; Rúa-Uribe, Guillermo; Correa, Margarita M; Conn, Jan E; Uribe-Soto, Sandra
Information about mosquito ecology in the high mountain ecosystems of the Neotropical region is sparse. In general, few genera and species have been reported in these ecosystems and there is no information available on habitats and the mosquitoes occupying them. In the present study, specimens collected from NW Colombia in HME were grouped using larval habitat data via an Operational Taxonomic Unit (OTU) determination. A total of 719 mosquitoes was analyzed belonging to 44 OTUs. The analysis considered habitat features and clustered the specimens into six groups from A-F. Five of these included species from different genera, suggesting common habitat requirements. Group E with four genera, seven subgenera, and six species occupied the highest areas (above 3,000 m), whereas three groups (B, D, F) were detected at lower altitudes (1,960-2,002 m). Bromeliads were the most common larval habitat, with 47% (335/719) of the specimens; five genera, six subgenera, and eight species were identified and classified into 66% (29/44) of the OTUs. This work showed some similarities to the habitat requirements and provides a grouping system that constitutes an important baseline for the classification of mosquito fauna from high mountain ecosystems according to altitude and larval habitat. © 2018 The Society for Vector Ecology.
Kramer, V L; Carper, E R; Beesley, C; Reisen, W K
Two mark-release-recapture studies were conducted along the Sacramento-San Joaquin River Delta in northern California to describe the population ecology and dispersal pattern of Aedes dorsalis (Meigen). Immature Ae. dorsalis were collected from saline tidal marshes, reared to adults, marked, and released. Recapture grids during the July and September studies were within 8.0 and 2.4 km of the release sites, and recapture rates were 0.1 and 1.2%, respectively. The longest recorded flight was 5.8 km, and mosquitoes were recaptured up to 15 d after release. In September, 84% of the marked mosquitoes were recaptured within 2.0 km of the release site, and the mean dispersal distance was 1.9 km. Marked mosquitoes flew predominantly downwind to the east. There was no evidence that Ae. dorsalis traversed the 1.6-km-wide river from Contra Costa to Solano County. Temporal and spatial recapture patterns indicated a possible short-range migration pattern from oviposition sites to upland host-seeking areas. Changes in the recapture rate with cohort age delineated a 7-d gonotrophic cycle during September.
Kho, Elise A; Hugo, Leon E; Lu, Guangjin; Smith, David D; Kay, Brian H
In order to assess the broad-scale applicability of field releases of Wolbachia for the biological control of insect-transmitted diseases, we determined the relationship between the larval diet of Aedes aegypti L. mosquitoes infected with Wolbachia strains and their susceptibility to dengue virus (DENV) infection via intrathoracic injection and oral inoculation. Larvae were reared on diets that varied in the quantity of food which had the effect of modifying development time and adult body size. Wolbachia wMel infection was associated with highly significant reductions in dengue serotype 2 (DENV-2) infection rates of between 80 and 97.5% following intrathoracic injection of adults emerging from three diet levels. Reductions were 100% in two diet level treatments following oral inoculation. Similarly, wMelPop infection was associated with highly significant reductions in DENV-2 infection rates of between 95 and 100% for intrathoracic injection and 97.5 and 100% for oral inoculation across diet level treatments. Larval diet level had no significant effect on DENV-2 infection rates in the presence of Wolbachia infection in mosquitoes that were intrathoracically injected with the virus. This indicates that the effectiveness of Wolbachia on vector competence disruption within Ae. aegypti is unlikely to be compromised by variable larval nutrition in field settings. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
In this study, chemical extracts of Jatropha curcas, Hyptis suaveolens, Abutilon indicum, and Leucas aspera were tested for toxicity to larvae of the filariasis vector Culex quinquefasciatus. Respective median lethal concentrations (LC50) for hexane, chloroform, ethyl acetate, and methanol extracts...
Full Text Available The presence of Anopheles (Nyssorhynchus dunhami Causey in Colombia (Department of Amazonas is confirmed for the first time through direct comparison of mtDNA cytochrome c oxidase I (COI barcodes and nuclear rDNA second internal transcribed spacer (ITS2 sequences with topotypic specimens of An. dunhami from Tefé, Brazil. An. dunhami was identified through retrospective correlation of DNA sequences following misidentification as Anopheles nuneztovari s.l. using available morphological keys for Colombian mosquitoes. That An. dunhami occurs in Colombia and also possibly throughout the Amazon Basin, is of importance to vector control programs, as this non-vector species is morphologically similar to known malaria vectors including An. nuneztovari, Anopheles oswaldoi and Anopheles trinkae. Species identification of An. dunhami and differentiation from these closely related species are highly robust using either DNA ITS2 sequences or COI DNA barcode. DNA methods are advocated for future differentiation of these often sympatric taxa in South America.
Traboulsi, Abdallah F; El-Haj, Samih; Tueni, Marie; Taoubi, Khalil; Nader, Natalie Abi; Mrad, Abir
The insecticidal activities of essential oil extracts from leaves, flowers and roots of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Foeniculum vulgare Mill were the most toxic, followed by those of Ferula hermonis Boiss, Citrus sinensis Osbeck, Pinus pinea L, Laurus nobilis L and Eucalyptus spp with LC50 values of 24.5, 44.0, 60.0, 75.0, 117.0 and 120.0 mg litre(-1), respectively. Combination tests between the LC50 and the maximum sub-lethal concentration (MSLC) were determined. Over 20 major components were identified in extracts from each plant species tested. Five essential oils and nine pure components were studied for their repellency against mosquito bites. Terpineol and 1,8-cineole were the most effective against Culex pipiens molestus bites offering complete protection for 1.6 and 2 h, respectively.
Alemayehu, Eba; Asale, Abebe; Eba, Kasahun; Getahun, Kefelegn; Tushune, Kora; Bryon, Astrid; Morou, Evangelia; Vontas, John; Van Leeuwen, Thomas; Duchateau, Luc; Yewhalaw, Delenasaw
The emergence and spread of insecticide resistance in the major African malaria vectors Anopheles gambiae (s.s.) and An. arabiensis may compromise the current vector control interventions and threatens the global malaria control and elimination efforts. Insecticide resistance was monitored in several study sites in Ethiopia from 2013 to 2015 using papers impregnated with discriminating concentrations of DDT, deltamethrin, bendiocarb, propoxur, malathion, fenitrothion and pirimiphos-methyl, following the WHO insecticide susceptibility test procedure. Mosquitoes sampled from different localities for WHO bioassay were morphologically identified as An. gambiae (s.l.) using standard taxonomic keys. Samples were identified to species using species-specific polymerase chain reaction (PCR) and screened for the presence of target site mutations L1014F, L1014S and N1575Y in the voltage gated sodium channel (VGSC) gene and G119S in the acethylcholinesterase (AChE) gene using allele-specific PCR. Biochemical assays were performed to assess elevated levels of acetylcholinesterases, carboxylcholinesterases, glutathione-S-transferases (GSTs) and cytochrome P450s monooxygenases in wild populations of An. arabiensis, compared to the fully susceptible Sekoru An. arabiensis laboratory strain. Populations of An. arabiensis were resistant to DDT and deltamethrin but were susceptible to fenitrothion in all the study sites. Reduced susceptibility to malathion, pirimiphos-methyl, propoxur and bendiocarb was observed in some of the study sites. Knockdown resistance (kdr L1014F) was detected in all mosquito populations with allele frequency ranging from 42 to 91%. Elevated levels of glutathione-S-transferases (GSTs) were detected in some of the mosquito populations. However, no elevated levels of monooxygenases and esterases were detected in any of the populations assessed. Anopheles arabiensis populations from all surveyed sites in Ethiopia exhibited resistance against DDT and pyrethroids. Moreover, some mosquito populations exhibited resistance to propoxur and possible resistance to bendiocarb. Target site mutation kdr L1014F was detected in all mosquito populations while elevated levels of glutathione-S-transferases (GSTs) was detected in some mosquito populations. The reduced susceptibility of An. arabiensis to propoxur and bendiocarb, which are currently used for indoor residual spraying (IRS) in Ethiopia, calls for continuous resistance monitoring, in order to plan and implement evidence based insecticide resistance management.
Pavela, R.; Vrchotová, Naděžda; Tříska, Jan
Roč. 165, mar (2016), s. 51-57 ISSN 0014-4894 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : botanical larvicide * Furanochromenes * Visnagin * Khellin * Sublethal effect * Mosquito Subject RIV: GC - Agronomy Impact factor: 1.724, year: 2016
Full Text Available Background. Outbreaks of the West Nile virus infection were reported in Morocco in 1996, 2003, and 2010. Culex pipiens was strongly suspected as the vector responsible for transmission. In the North center of Morocco, this species has developed resistance to synthetic insecticides. There is an urgent need to find alternatives to the insecticides as natural biocides. Objective. In this work, the insecticidal activity of the extract of the local plant Nerium oleander, which has never been tested before in the North center of Morocco, was studied on larval stages 3 and 4 of Culex pipiens. Methods. Biological tests were realized according to a methodology inspired from standard World Health Organization protocol. The mortality values were determined after 24 h of exposure and LC50 and LC90 values were calculated. Results. The extract had toxic effects on the larvae of culicid mosquitoes. The ethanolic extract of Nerium oleander applied against the larvae of Culex pipiens has given the lethal concentrations LC50 and LC90 in the order of 57.57 mg/mL and 166.35 mg/mL, respectively. Conclusion. This investigation indicates that N. oleander could serve as a potential larvicidal, effective natural biocide against mosquito larvae, particularly Culex pipiens.
Fábio Saito Monteiro de Barros
Full Text Available We performed a longitudinal study of adult survival of Anopheles darlingi, the most important vector in the Amazon, in a malarigenous frontier zone of Brazil. Survival rates were determined from both parous rates and multiparous dissections. Anopheles darlingi human biting rates, daily survival rates and expectation of life where higher in the dry season, as compared to the rainy season, and were correlated with malaria incidence. The biting density of mosquitoes that had survived long enough for completing at least one sporogonic cycle was related with the number of malaria cases by linear regression. Survival rates were the limiting factor explaining longitudinal variations in Plasmodium vivax malaria incidence and the association between adult mosquito survival and malaria was statistically significant by logistic regression (P<0.05. Survival rates were better correlated with malaria incidence than adult mosquito biting density. Mathematical modeling showed that P. falciparum and P. malariae were more vulnerable to changes in mosquito survival rates because of longer sporogonic cycle duration, as compared to P. vivax, which could account for the low prevalence of the former parasites observed in the study area. Population modeling also showed that the observed decreases in human biting rates in the wet season could be entirely explained by decreases in survival rates, suggesting that decreased breeding did not occur in the wet season, at the sites where adult mosquitoes were collected. For the first time in the literature, multivariate methods detected a statistically significant inverse relation (P<0.05 between the number of rainy days per month and daily survival rates, suggesting that rainfall may cause adult mortality.
Oswaldo Paulo Forattini
Full Text Available Based on type examination, Culex (Melanoconion theobaldi (Lutz, 1904 is redescribed. The species Cx. (Mel. chrysonotum Dyar & Knab, 1908, was put back as synonym of theobaldi. Besides, examination of Cx. (Mel. chrysothorax (Newstead & Thomas, 1910 type, leads to retiring as synonym of theobaldi and considered it as "species inquirenda".
Full Text Available Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas. Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.
Full Text Available Background: The expansion of herbicide used in aquatic ecosystems as well as in terrestrial if is not properly controlled may produce harmful effects on freshwater fisheries. Residue limits of these agricultural chemicals in tropical fishery waters should be established. The aim of this study was to determine the acute toxicity of butachlor and pertilachlor as potential dangerous herbicides to assess mortality effects of these chemicals to the Mosquito Culex quinquefasciatus. Methods: This study was carried out in Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran at summer 2013. Culex samples were exposed to different concentrations of butachlor and pertilachlor (0-200ppm for butachlor and pertilachlor for 96 h. Results: The low toxicity of LC50s obtained for butachlor (23.81±0.04 and pertilachlor (27.97±0.05 indicate that butachlor and pertilachlor were lowly toxic to Mosquito Cu. quinquefasciatus. Conclusion: Although pretilachlor and butachlor are low toxic but pretilachlor is less toxic in field conditions, these data are useful to potential ecosystem risk assessment.
Loetti, V.; Schweigmann, N.J.; Burroni, N.E., E-mail: firstname.lastname@example.org [Universidad de Buenos Aires (Argentina). Facultad de Ciencias Exactas y Naturales. Grupo de Estudio de Mosquitos
The effect of constant temperatures on the development time from first instar to adult emergence was studied in Culex eduardoi Casal and Garcia reared at 7, 10, 15, 20, 25, 30 or 33 deg C. Data were adjusted to the linear degree-day model and the nonlinear Briere model. According to the linear model, the development time was inversely related to the rearing temperatures between 7 deg C and 25 deg C. Maximum mortality (100%) was recorded at temperatures > 30 deg C. According to the linear model, the development threshold temperature and thermal constant were 5.7 deg C and 188.8 degree days, respectively. The lower and upper threshold temperatures and the optimum temperature for the nonlinear model were -2.3, 30.0 and 28.1 deg C, respectively. (author)
Estep, Alden S; Sanscrainte, Neil D; Waits, Christy M; Louton, Jessica E; Becnel, James J
Puerto Rico (PR) has a long history of vector-borne disease and insecticide-resistant Aedes aegypti (L.). Defining contributing mechanisms behind phenotypic resistance is critical for effective vector control intervention. However, previous studies from PR have each focused on only one mechanism of pyrethroid resistance. This study examines the contribution of P450-mediated enzymatic detoxification and sodium channel target site changes to the overall resistance phenotype of Ae. aegypti collected from San Juan, PR, in 2012. Screening of a panel of toxicants found broad resistance relative to the lab susceptible Orlando (ORL1952) strain. We identified significant resistance to representative Type I, Type II, and nonester pyrethroids, a sodium channel blocker, and a sodium channel blocking inhibitor, all of which interact with the sodium channel. Testing of fipronil, a chloride channel agonist, also showed low but significant levels of resistance. In contrast, the PR and ORL1952 strains were equally susceptible to chlorfenapyr, which has been suggested as an alternative public health insecticide. Molecular characterization of the strain indicated that two common sodium channel mutations were fixed in the population. Topical bioassay with piperonyl butoxide (PBO) indicated cytochrome P450-mediated detoxification accounts for approximately half of the resistance profile. Transcript expression screening of cytochrome P450s and glutathione-S-transferases identified the presence of overexpressed transcripts. This study of Puerto Rican Ae. aegypti with significant contributions from both genetic changes and enzymatic detoxification highlights the necessity of monitoring for resistance but also defining the multiple resistance mechanisms to inform effective mosquito control. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.
Blosser, Erik M; Lord, Cynthia C; Stenn, Tanise; Acevedo, Carolina; Hassan, Hassan K; Reeves, Lawrence E; Unnasch, Thomas R; Burkett-Cadena, Nathan D
Field studies were carried out in four Florida counties to investigate winter and spring ecology of host use by Culiseta melanura (Coquillet), the primary vector of eastern equine encephalomyelitis virus (EEEV) in North America. Bloodmeal analysis by PCR was used to identify 233 host bloodmeals, which mainly originated from birds (78.5%) and reptiles (17.2%), primarily Anolis spp. lizards. Across counties, the percentage of bloodmeals from reptiles (7-37% depending upon county) increased with increasing day length and temperature in the spring. Multiple logistic regression revealed that differences in reptile host use across collection sites were largely explained by differences in average day length and temperature on the day of collection, and is probably owing to environment-driven behavioral patterns of ectothermic animals. Although past studies have demonstrated reptile biting by epizootic vectors of EEEV, including Culex (Melanoconion) spp., this is the first study to demonstrate widespread and common feeding upon ectothermic hosts by Cs. melanura. This work suggests that reptiles, particularly anole lizards, play a role in the ecology of EEEV in Florida either as amplifying hosts or as noncompetent hosts which dilute vector feedings thereby suppressing transmission. Detailed laboratory studies investigating impacts of environmental variables (temperature and photoperiod) on EEEV competence of anoles are needed to assess whether these animals support virus amplification. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Oswaldo Paulo Forattini
Full Text Available New research concerning Anopheles bellator in the southeast of the State of São Paulo, Brazil, are reported. Adult females of this mosquito showed remarkable endophily and endophagy which was even greater than An. cruzii. The epidemiological role of this anopheline as a malaria vector is discussed.
2 pl. 1966. Mosquitos de Venezuela. Vol. 1. Galindo, P. 1973. Experiencias epidemiolo- Ministerio de Sanidad y Asistencia Social, gicas en el Proyecto ...Heinemann, S.J. and J.N. Belkin. 1977b. Col- Facultad de Ciencias Biologia. Universidad lection records of the project "Mosquitoes Nacional Autonoma de
guinea pig blood and a 10% sucrose solution to develop ovaries and lay eggs . After 24 h, those females in good condition and well-fed were separated for...each individual labeled to maintain the as- sociation between each female and the corresponding egg batch. Eggs from each female were kept separate...spot/length of the distal sector dark spot (DS-III2/Ta-III2, HP/PHD, SCP/DSD) approximately 5% of the adult females were misidentified as a species
Porretta, Daniele; Mastrantonio, Valentina; Crasta, Graziano; Bellini, Romeo; Comandatore, Francesco; Rossi, Paolo; Favia, Guido; Bandi, Claudio; Urbanelli, Sandra
Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1) has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4) of Anopheles gambiae (s.s.) and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size) on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s.) than in An. stephensi. In both species the total number of cannibalistic events increased from 0-24 to 0-48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s.) and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior and lower cannibalism rate. The understanding of cannibalistic behavior and the factors affecting it is of utmost importance for malaria vectors, as nutrition during larval development can strongly affect the fitness of adult female mosquitoes and ultimately their vector ability.
Full Text Available Abstract Background Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1 has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4 of Anopheles gambiae (s.s. and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Results Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s. than in An. stephensi. In both species the total number of cannibalistic events increased from 0–24 to 0–48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. Conclusions The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s. and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior and lower cannibalism rate. The understanding of cannibalistic behavior and the factors affecting it is of utmost importance for malaria vectors, as nutrition during larval development can strongly affect the fitness of adult female mosquitoes and ultimately their vector ability.
Richards, Stephanie L; Lord, Cynthia C; Pesko, Kendra N; Tabachnick, Walter J
Interactions between environmental and biological factors affect the vector competence of Culex pipiens quinquefasciatus for West Nile virus. Three age cohorts from two Cx. p. quinquefasciatus colonies were fed blood containing a low- or high-virus dose, and each group was held at two different extrinsic incubation temperatures (EIT) for 13 days. The colonies differed in the way that they responded to the effects of the environment on vector competence. The effects of mosquito age on aspects of vector competence were dependent on the EIT and dose, and they changed depending on the colony. Complex interactions must be considered in laboratory studies of vector competence, because the extent of the genetic and environmental variation controlling vector competence in nature is largely unknown. Differences in the environmental (EIT and dose) and biological (mosquito age and colony) effects from previous studies of Cx. p. quinquefasciatus vector competence for St. Louis encephalitis virus are discussed.
Nikos G. Chorianopoulos
Full Text Available The chemical composition of the essential oils of the wild growing plants of Greek S. spinosa L., S. parnassica subsp. parnassica Heldr.& Sart ex Boiss., S. thymbra and S. montana were determined by GC and GC/MS analysis. The larvicidal activities of the essential oils were assayed against Culex pipiens biotype molestus. The analytical data indicated that various monoterpene hydrocarbons and phenolic monoterpenes constitute the major constituents of the oils, but their concentration varied greatly among the oils examined. The bioassay results indicated that the oils possess significant larvicidal activities and represent an inexpensive source of natural substances mixture that exhibit potentials for use to control the mosquito larvae.
Full Text Available Objective: To evaluate immature mosquitocidal properties of Xanthium strumarium plant extracts against Culex mosquitoes at Entomology Laboratory, Maraki Campus, University of Gondar. Methods: The immature mosquitocidal activity of plant extracts was tested by following World Health Organization recommended protocol. Acetone, methanol and water extracts were prepared at 50, 100, 150, 200 and 250 mg/L concentrations and tested against third and fourth instar larvae and pupae of Culex mosquitoes. The mortality rate of immature mosquitoes was recorded after 24, 48 and 72 h exposure period continuously. Results: Third instar larvae after 24 h exposure period, maximum mortality of 77.80% was recorded at 250 mg/L concentration of acetone extract. After 48 h and 72 h exposure period, maximum mortality of 88.90% was recorded in acetone extract in all the tested concentration. The maximum mortality of fourth instar larvae was 88.90% in acetone extract at 200 and 250 mg/L concentrations. Pupal mortality was also greater in acetone extract. The percentage of mortality in all the stage of mosquitoes was higher in acetone extract followed by methanol and water extract. Conclusions: The percentage of mortality is associated with concentration of the extracts tested and exposure period. This laboratory study confirmed immature mosquitocidal activity of Xanthium strumarium leaf extracts against Culex mosquitoes. The aqueous leaf extract can be used by applying on small man-made breeding places to prevent adult emergence.
Full Text Available Background: During recent years transmission of Dirofilaria immitis (dog heart worm by Culex pipiens and West Nile virus have been reported from Iran. The present study was preformed for evaluating the susceptibility status of Cx. pipiens collected from capital city of Tehran, Iran.Methods: Four Insecticides including: DDT 4%, Lambdacyhalothrin 0.05%, Deltamethrin 0.05% and Cyfluthrin 0.15 % according to WHO standard methods were used for evaluating the susceptibility status of Cx. pipiens from Tehran moreover For comparison susceptibility status a Laboratory strain also was used. Bioassay data were analyzed using Probit program. The lethal time for 50% and 90% mortality (LT50 and LT90 values were calculated from regression line.Results: The susceptibility status of lab strain of Cx. pipiens revealed that it is susceptible to Lambdacyhalothrin, Deltamethrin, Cyfluthrin and resistant to DDT. Moreover cyfluthrin with LT50=36 seconds and DDT with LT50=3005 seconds had the least and most LT50s. Field population was resistance to all tested insecticides and DDT yielded no mortality.Conclusion: Highly resistance level against all WHO recommended imagicides were detected in field populations. We suggest more biochemical and molecular investigations to detect resistance mechanisms in the field population for further decision of vector control.
Background Anopheles sinensis is the major malaria vector in China and Southeast Asia. Vector control is one of the most effective measures to prevent malaria transmission. However, there is little transcriptome information available for the malaria vector. To better understand the biological basis of malaria transmission and to develop novel and effective means of vector control, there is a need to build a transcriptome dataset for functional genomics analysis by large-scale RNA sequencing (RNA-seq). Methods To provide a more comprehensive and complete transcriptome of An. sinensis, eggs, larvae, pupae, male adults and female adults RNA were pooled together for cDNA preparation, sequenced using the Illumina paired-end sequencing technology and assembled into unigenes. These unigenes were then analyzed in their genome mapping, functional annotation, homology, codon usage bias and simple sequence repeats (SSRs). Results Approximately 51.6 million clean reads were obtained, trimmed, and assembled into 38,504 unigenes with an average length of 571 bp, an N50 of 711 bp, and an average GC content 51.26%. Among them, 98.4% of unigenes could be mapped onto the reference genome, and 69% of unigenes could be annotated with known biological functions. Homology analysis identified certain numbers of An. sinensis unigenes that showed homology or being putative 1:1 orthologues with genomes of other Dipteran species. Codon usage bias was analyzed and 1,904 SSRs were detected, which will provide effective molecular markers for the population genetics of this species. Conclusions Our data and analysis provide the most comprehensive transcriptomic resource and characteristics currently available for An. sinensis, and will facilitate genetic, genomic studies, and further vector control of An. sinensis. PMID:25000941
Full Text Available Objective: To examine Beauveria bassiana (B. bassiana fungus bioassay against the larval stages of Anopheles stephensi in Iran. Methods: The fungal suspension by the concentrations of 1伊1 09, 5伊1 08, 1 08, 5伊1 07 and 1伊 107 conidia per milliliter have been prepared in different volumes (2, 4 and 6 mL and each concentration were added to containers containing 25 Anopheles larva instars 1 and 2. The mortality of the dead larvae with abnormal symptoms was recorded as a result of the fungal infection after 24, 48 and 72 h. Results: Comparison between the mean mortality rate of Anopheles stephensi larva at different concentrations of B. bassiana strain Iran 429C at 2, 4 and 6 mL showed that there was no significant relation of the mean mortality rate of larvae at concentrations of 1伊109 and 5伊108, and after 48 h resulted in 100% mortality rate of the larvae populations. In addition, there is no significant differences in the amounts of lethal times (LT (LT50 and LT90 as LT90 values calculated at a concentration of 5伊108 and in volumes 2, 4 and 6 mL were 1.46, 1.36 and 1.08 d, respectively. Conclusions: B. bassiana strain Iran 429C in 2 mL of 5伊108 concentration or the concentration of a 1伊109 mL per 100 mL of water is recommended as the optimal concentration for the control of Anopheles larvae. The development of suitable formulations of entomopathogenic fungi may be a promising prospect in the mosquito control programs.
Vivekanandhan, Perumal; Kavitha, Thangaraj; Karthi, Sengodan; Senthil-Nathan, Sengottayan; Shivakumar, Muthugoundar Subramanian
Microbial-based pest control is an attractive alternative to chemical insecticides. The present study sought to evaluate the toxicity of the entomopathogenic fungus Beauveria bassiana -28 ethyl acetate extracts on different larval stages and pupae of Culex quinquefasciatus mosquitoes. B. bassiana -28 ethyl acetate mycelial extracts produced mosquitocidal activity against larvae and pupae which was comparable to that of the commercial insecticide B. bassiana -22 extract. The LC 50 (lethal concentration that kills 50% of the exposed larvae) values of B. bassiana -28 extracts for 1st to 4th instar larvae and pupae were 11.538, 6.953, 5.841, 3.581 and 9.041 mg/L respectively. Our results show that B. bassiana -28 ethyl acetate mycelial extract has strong insecticidal activity against larval and pupal stages of Cx. quinquefasciatus . Fourier transform infrared spectrum study of B. bassiana -28 extract shows peaks at 3226.91; 2927.94; 1593.13; 1404.18; 1224.18; 1247.94; 1078.21; 1018.41; 229.69; and 871.82 cm -1 . Major spectral peaks were observed at 3226.91 cm -1, assigned to N-H stretching, 2927.94 cm -1 assigned to C-H bonding and 1595.13 cm -1 assigned to C-O stretching. Gas Chromatography-Mass Spectrometry studies of B. bassiana -28 ethyl acetate crude extract showed presence of six major compounds viz. N -hexadecanoic acids (13.6040%); Z,Z -9,12 octadecadienic acid (33.74%); 9-eicosyne (10.832%); heptacosane (5.148%); tetrateracontane (5.801%); and 7 hexyleicosane (5.723%). Histology of mosquito midgut tissue shows tissue lysis as a result of B.bassiana -28 extract exposure. The study shows that bioactive molecules obtained from B. bassiana -28 mycelial extract has insecticidal properties and can be used as alternative for mosquito control.
Full Text Available Microbial-based pest control is an attractive alternative to chemical insecticides. The present study sought to evaluate the toxicity of the entomopathogenic fungus Beauveria bassiana-28 ethyl acetate extracts on different larval stages and pupae of Culex quinquefasciatus mosquitoes. B. bassiana-28 ethyl acetate mycelial extracts produced mosquitocidal activity against larvae and pupae which was comparable to that of the commercial insecticide B. bassiana-22 extract. The LC50 (lethal concentration that kills 50% of the exposed larvae values of B. bassiana-28 extracts for 1st to 4th instar larvae and pupae were 11.538, 6.953, 5.841, 3.581 and 9.041 mg/L respectively. Our results show that B. bassiana-28 ethyl acetate mycelial extract has strong insecticidal activity against larval and pupal stages of Cx. quinquefasciatus. Fourier transform infrared spectrum study of B. bassiana-28 extract shows peaks at 3226.91; 2927.94; 1593.13; 1404.18; 1224.18; 1247.94; 1078.21; 1018.41; 229.69; and 871.82 cm−1. Major spectral peaks were observed at 3226.91 cm−1, assigned to N–H stretching, 2927.94 cm−1 assigned to C–H bonding and 1595.13 cm−1 assigned to C–O stretching. Gas Chromatography-Mass Spectrometry studies of B. bassiana-28 ethyl acetate crude extract showed presence of six major compounds viz. N-hexadecanoic acids (13.6040%; Z,Z-9,12 octadecadienic acid (33.74%; 9-eicosyne (10.832%; heptacosane (5.148%; tetrateracontane (5.801%; and 7 hexyleicosane (5.723%. Histology of mosquito midgut tissue shows tissue lysis as a result of B.bassiana-28 extract exposure. The study shows that bioactive molecules obtained from B. bassiana-28 mycelial extract has insecticidal properties and can be used as alternative for mosquito control.
.... Experiments using Venezuelan equine encephalitis viral replicon particles, which express the green fluorescent protein gene in cells, indicate the operation of tissue conduits, possibly involving...
Andrés G. Rueda
Full Text Available Aedes aegypti is the principal vector of arboviral pathogens that may cause diseases as dengue fever, chikungunya and zika. The harmful environmental effects of commercial pesticides coalesced with the development of insecticide-resistant populations encourage the discovery and generation of new alternative products as a tool to reduce the incidence of vector-borne diseases. In this work, through the classic three component Strecker reaction of commercial benzaldehydes, cyclic secondary amines and KCN, a new series of nine α-amino nitriles, girgensohnine analogs, has been synthetized and screened for larvicide and adulticide properties against A. aegypti, one of the dominant vectors of dengue, chikungunya and zika in tropical and subtropical areas all over the world. Molecules 3 and 4 were identified as potential larvicidal agents with LC50 values of 50.55 and 69.59 ppm, respectively. Molecule 3 showed 100% of mortality after 2 h of treatment when a concentration of 30 ppm in adulticidal assays was evaluated. Additionally, in order to elucidate the mode of action of these molecules, their acetylcholinesterase (AChE inhibitory properties were evaluated using the Ellman assay. It was found that the molecules possess a weak AChE inhibitory activity with IC50 values between 148.80 and 259.40 μM, indicating that AChE could not be a principal target for insecticide activity. Keywords: Arthropod-borne diseases, Girgensohnine analogs, Strecker reaction, Insecticidal activity, Vector control
Full Text Available The search for new insecticides to control dengue fever, chikungunya, and Zika vectors has gained relevance in the past decades. The aim of the present study was to evaluate the larvicidal action of essential oils (EOs from Thymus vulgaris, Salvia officinalis, Lippia origanoides, Eucalyptus globulus, Cymbopogon nardus, Cymbopogon martinii, Lippia alba, Pelargonium graveolens, Turnera diffusa, and Swinglea glutinosa on Aedes (Stegomyia aegypti. The EOs were extracted by microwave-assisted hydrodistillation and characterized by gas chromatography/mass spectrometry (GC/MS. The chemical components of the EOs were identified by linear retention indices and mass spectra. Lethal concentrations (LC50 and LC95 were determined by probit analysis using larvae of Ae. aegypti between the third and the fourth instars. All EOs achieved larvicidal activity at LC50 values lower than 115 mg/L. The lowest LC50 value (45.73 mg/L corresponded to T. vulgaris EO, whereas C. martinii EO showed the highest LC50 (LC50 = 114.65 mg/L. Some EO mixtures showed lower LC50 than oils used individually, such as the mixtures of L. origanoides + S. glutinosa (LC50 = 38.40 mg/L, T. diffusa + S. glutinosa (LC50 = 63.71 mg/L, and L. alba + S. glutinosa (LC50 = 48.87 mg/L. The main compounds of the EOs with highest larvicidal activity were thymol (42% and p-cymene (26.4%. Keywords: Essential oil, Larvicidal activity, Mosquito control
Alvarez, Leslie C; Ponce, Gustavo; Oviedo, Milagros; Lopez, Beatriz; Flores, Adriana E
Temephos is an insecticide widely used in Venezuela to control the proliferation of the larvae of Aedes aegypti (L.), the principal vector of dengue virus. The aim of this study was to identify the susceptibility to temephos of Ae. aegypti in four locations in western Venezuela: Lara, Tres Esquinas, Ureña and Pampanito. Larval bioassays were conducted on samples collected in 2008 and 2010, and the levels of α- and β-esterases, mixed-function oxidases, glutathione-S-transferase and insensitive acethyl cholinesterase were determined. Larval populations from western Venezuela obtained during 2008 and 2010 were found to be susceptible to temephos, with low resistance ratios and without overexpression of enzymes. The low RR values reveal the effectiveness of temephos in controlling the larval populations of Ae. aegypti. Control strategies must be vigorously monitored to maintain the susceptibility to temephos of these populations of Ae. aegypti. © 2013 Society of Chemical Industry.
Full Text Available Se describen los síntomas en larvas de A. aquasalis infectadas naturalmente con un microsporidio parasítico, y la ultraestructura de las esporas del mismo. Las larvas fueron criadas bajo condiciones de laboratorio en concentraciones de salinidad de 10 g/l y 20 g/l, registrándose diariamente la mortalidad y la fecha del cambio de estadío de las mismas. Las larvas infectadas fueron procesadas por rnicroscopía electrónica de transmisión usando métodos convencionales con pH 7.2 y 260 mOsm/I. El incremento de la infección por los microsporidios estuvo correlacionado positivamente con un aumento en la duración promedio del cuarto estadío de 2.88 a 6.33 días en 10 g/l de sal y de 2.47 a 6.14 días en 20 g/l. La mortalidad de las larvas también aumentó en aproximadamente 50% durante este estadío a ambas concentraciones de salinidad. No se observaron estas alteraciones en los otros estadíos. Las esporas maduras de los microsporidios fueron encontradas en el intestino de las larvas. Estas esporas mostraron forma de barril y dimensiones de 2.6 x 2.4 µm aproximadamente. La reducción en la supervivencia de las larvas de A. aquasalis infectadas con los microsporidios, y el aumento del tiempo de su desarrollo sugiere que este parásito podría ser un posible controlador biológico de esta plaga. El microsporidio descrito presenta características similares a las del género Parathelohania. Se sugiere que el microsporidio encontrado en las larvas de A. aquasalis es una especie nueva y se propone nombrarla Parathelohania aquasalensis. Este trabajo representa el primer reporte de un microsporidio encontrado en un díptero en Venezuela.The symptoms of Anopheles aquasalis larvae naturally infected by a microsporidium, and the ultrastructure of the infecting spores is describes. The larvae were maintained under laboratory conditions in salt concentrations of 10 g/l and 20 g/l of water. Daily recordings of the mortality of the larvae were made and the dates of change of instar were noted. Infected larvas were processed for transmission electronic microscopy using conventional methods at pH 7.2 and 260 mOsm/l. The infection by the microsporidia was positively correlated with an increase in the mean duration of the fourth instar of 2.88 to 6.33 days in 10 g/l of salt and of 2.47 to 6.14 days in 20 g/l of salt. Larval mortality also increased by approximately 50% during this instar in both salt concentrations. Development time and survival were not affected during the other immature stages. The mature spores found in the intestines of infected larvae were barrel shaped and measured approximately 2.6 x 2.4 mm. The exospore has a collar shaped prolongation at the posterior end of the spore. The spores are uninuclear with a posterior vacuole. The polar filament is anisofilar with nine rings, five with a diameter of 58 nm each and four with a diameter of 23 nm each. The polarplast is lamellate, and more tightly packed in the apical region. The reduction of the survival of A. aquasalis larvae infected with the microsporidia, and the increase in the development time suggest that this parasite might have a potential as a biological control of this pest. The microsporidium describes here has similar characteristics to that of the genus Parathelohania. I suggest that the rnicrosporidium found in A. aquasalis represents a new species and I propose the name Parathelohania aquasalensis. This is the first report of a microsporidium from a dipteran in Venezuela.
McPhatter, Lee P; Su, Tianyun; Williams, Greg; Cheng, Min-Lee; Dhillon, Major; Gerry, Alec C
Knowledge of the blood-feeding patterns exhibited by arthropod vectors is essential for understanding the complex dynamics of vector-borne disease transmission. Some species of mosquitoes belonging to the genus Culex have been implicated as having major roles in the transmission of arboviruses such as West Nile virus, Saint Louis encephalitis virus, and Western equine encephalitis virus. Although the host-feeding patterns for many of these Culex species are well studied, the host-feeding patterns of Culex stigmatosoma Dyar are relatively poorly studied, even though this species is suspected to be an important maintenance vector for West Nile virus and other arboviruses. In the current study, bloodmeals from 976 blood-engorged Cx. stigmatosoma, collected from 30 sites in southern California from 2009-2012, were processed for vertebrate host identification by nucleotide sequencing following polymerase chain reaction to amplify portions of the cytochrome oxidase I and cytochrome b genes of vertebrate animals. Vertebrate DNA was amplified, sequenced, and identified from a total of 647 Cx. stigmatosoma bloodmeals, revealing that 98.6% of bloodmeals were from birds, 1.2% from three mammal species, and a single bloodmeal was from a reptile species. In total, 40 different host species were identified. The greatest number of bloodmeals identified was from domestic chicken (Gallus gallus domesticus L.) (38% of bloodmeals), house sparrow (Passer domesticus L.) (23%), house finch (Haemorhous mexicanus Müller) (17%), American crow (Corvus brachyrhynchos L.) (4%), and mourning dove (Zenaida macroura L.) (3%). However, chicken bloodmeals were identified almost entirely from a single site where mosquito collection devices were placed in the near vicinity of confined domestic chickens. The strongly ornithophilic feeding behavior shown in this study for Cx. stigmatosoma supports the hypothesis that this mosquito species may be an important maintenance (or endemic) vector for arboviruses that circulate among susceptible birds. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: firstname.lastname@example.org.
Richards, Stephanie L; Anderson, Sheri L; Yost, Samantha A
Culex pipiens quinquefasciatus were fed blood meals from a live chicken (LC), chicken blood in Alsever's (AC) solution, defibrinated bovine blood (DB), or bovine blood in citrate (CB) and incubated at 28° C. The effects of different blood meal sources were evaluated with respect to rates of blood feeding and reproduction (i.e., fecundity and fertility) over two gonotrophic cycles. Mosquitoes that fed on the first blood meal were subjected to a second blood meal as follows (first blood meal / second blood meal): LC/LC, LC/DB, DB/DB, CB/CB, AC/AC. Fecundity and fertility of Cx. p. quinquefasciatus were significantly (P blood; however, fecundity and fertility in different treatment groups varied by gonotrophic cycle. These results contribute to our understanding of the impact of blood meal source on feeding and reproduction in Cx. p. quinquefasciatus. The potential impacts of blood meal source on virus transmission experiments are discussed. © 2012 The Society for Vector Ecology.
Full Text Available The aim was to survey the specific factors, which cause to decrease blood feeding of mosquitoes important to succeed vector control.Larval collection was carried out from fixed and variable breeding places of Yazd County, central Iran in 2009. Autogeny-Anautogeny, Stenogamy-Eurygamy, and blood preference of Culex pipiens were studied using standard mosquito cages blood meal source for Cx. pipiens females considered as the chickens and human and fed females were kept in insectary condition (16:8 L: D, 27±3 °C and 70±10% RH. The data were analyzed using SPSS Ver. 11.5 soft ware.Totally, 96 females' mosquitoes were tested for Stenogamy versus Eurygamy and 122 for blood preference assay. In the small cages (20 × 20 × 20cm and large cage (60 × 40 × 60cm, the ability of mating and insemination rates were 60.0 and 67.0%, respectively. In spite of Cx. pipiens fed from sucrose 5%, none of them laying eggs in 60 × 40 × 60 cages during the study. This finding indicated the Anautogeny behavior of this species. This species was found of low tendency to human blood and almost 4 fold fed on chicken.The occurrence of Steno-Eurygamy, Anautogeny, and Ornithophilic behaviors of Cx. Pipiens was noted. More studies need to be carried out about the bionomics of this species to gain more data about the ecophysiological and behavioral characteristics in other parts of Iran.
Chareonviriyaphap, Theeraphap; Prabaripai, Atchariya; Bangs, Michael J; Aum-Aung, Boonserm
Anopheline mosquito larvae and adults were sampled at Ban Pu Teuy, Tri-Yok District, Kanchanaburi Province, western Thailand, from January 2000 to December 2001. Over the period of 2 yr, Anopheles minimus sensu lato was the most commonly collected species, followed by Anopheles swadiwongporni and Anopheles dirus sensu lato; all three species are important vectors of malaria in Thailand. Attempted blood feeding by An. minimus occurred throughout the night, with two distinct feeding peaks: strong activity immediately after sunset (1800-2100 hours), followed by a second, less pronounced, rise before sunrise (0300-0600 hours). Anopheles minimus were more abundant during the wet season compared with the dry and hot seasons, although nocturnal adult feeding patterns were similar. Anopheles minimus fed readily on humans inside and outside of houses, showing a slight preference for exophagy. The human-biting peak of An. minimus in our study area differed from other localities sampled in Thailand, indicating the possible existence of site-specific populations of An. minimus exhibiting different host-seeking behavior. These results underscore the importance of conducting site-specific studies to accurately determine vector larval habitats and adult activity patterns and linking their importance in malaria transmission in a given area.
Hall-Mendelin, Sonja; Jansen, Cassie C; Cheah, Wai Yuen; Montgomery, Brian L; Hall, Roy A; Ritchie, Scott A; Van den Hurk, Andrew F
Japanese encephalitis virus (JEV) transmission in northern Australia has, in the past, been facilitated by Culex annulirostris Skuse feeding on domestic pigs, the primary amplifying hosts of the virus. To further characterize mosquito feeding behavior in northern Australia, 1,128 bloodmeals from Cx. annulirostris were analyzed using a double-antibody enzyme-linked immunosorbent assay. Overall, Cx. annulirostris obtained > 94% of blood meals from mammals, comprising marsupials (37%), pigs (20%), dogs (16%), and cows (11%), although the proportion feeding on each of these host types varied between study locations. Where JEV activity was detected, feeding rates on pigs were relatively high. At the location that yielded the first Australian mainland isolate of JEV from mosquitoes, feral pigs (in the absence of domestic pigs) accounted for 82% of bloodmeals identified, representing the first occasion that feeding on feral pigs has been associated with JEV transmission in Australia. Interestingly, blood meals identified, or infected mosquitoes immigrating from areas where domestic pigs are housed, may have contributed to transmission at this location. Because Cx. annulirostris is both an opportunistic feeder and the primary JEV vector in the region, environmental characteristics and host presence can determine JEV transmission dynamics in northern Australia.
Turell, Michael J; Wilson, William C; Bennett, Kristine E
To determine which arthropods should be targeted for control should Rift Valley fever virus (RVFV) be detected in North America, we evaluated Culex erraticus (Dyar and Knab), Culex erythrothorax Dyar, Culex nigripalpus Theobald, Culex pipiens L., Culex quinquefasciatus Say, Culex tarsalis Coquillett, Aedes dorsalis (Wiedemann), Aedes vexans (Meigen), Anopheles quadrimaculatus Say, and Culicoides sonorensis Wirth and Jones from the western, midwestern, and southern United States for their ability to transmit RVFV. Female mosquitoes were allowed to feed on adult hamsters inoculated with RVFV, after which engorged mosquitoes were incubated for 7-21 d at 260C, then allowed to refeed on susceptible hamsters, and tested to determine infection, dissemination, and transmission rates. Other specimens were inoculated intrathoracically, held for 7 d, and then allowed to feed on a susceptible hamster to check for a salivary gland barrier. When exposed to hamsters with viremias > or =10(8.8) plaque-forming units/ml blood, Cx. tarsalis transmitted RVFV efficiently (infection rate = 93%, dissemination rate = 56%, and estimated transmission rate = 52%). In contrast, when exposed to the same virus dose, none of the other species tested transmitted RVFV efficiently. Estimated transmission rates for Cx. erythrothorax, Cx. pipiens, Cx. erraticus, and Ae. dorsalis were 10, 8, 4, and 2%, respectively, and for the remaining species were feeding preference, longevity, and foraging behavior should be considered when determining the potential role that these species could play in RVFV transmission.
Finlayson, Catherine; Saingamsook, Jassada; Somboon, Pradya
This study developed an artificial feeding (AF) method to replace direct host feeding (DHF) for the maintenance of Aedes aegypti and Anopheles minimus mosquito colonies. The procedure can be adopted by all laboratories due to its simple and affordable materials and design. The apparatus consists of heparinized cow blood contained in a 5cm diameter glass petri dish with 5cm(2) Parafilm M (Bemis(®)) stretched thinly over the top, with a pre-heated bag of vegetable oil placed underneath to keep the blood warm. Both parts are contained within an insulated Styrofoam™ box with a hole in the lid for mosquitoes to access the membrane. Mosquitoes are fed by AF for 15min at a time. Feeding rate and fecundity of Ae. aegypti mosquitoes feeding on the AF device were compared to those feeding on a live rat (DHF(r)), and of Anopheles minimus mosquitoes feeding on the AF device compared to those feeding on a human arm (DHF(h)). Aedes aegypti mosquitoes fed by AF or DHF(r) had similar feeding rates (38.2±21.5% and 35.7±18.2%, respectively) and overall egg production (1.5% difference). Anopheles minimus mosquitoes fed by the AF method had a lower feeding rate (52.0±1.0% for AF compared to 70.7±20.2% for DHF(h)) and overall egg production (40% reduction compared to DHF(h)). However, the number of eggs produced by AF-fed mosquitoes (1808 eggs per 100 mosquitoes) was still sufficient for colony maintenance, and with increased feeding time both parameters are expected to increase. Reduced feeding rate and overall egg production was observed when Ae. aegypti mosquitoes were fed on blood refrigerated for over two weeks. In conclusion, an AF device has been developed which can replace DHF for Ae. aegypti and An. minimus colony maintenance when using blood refrigerated for a maximum of two weeks. Copyright © 2015 Elsevier B.V. All rights reserved.
Victor A. Brugman
Full Text Available Over the past three decades, a range of mosquito-borne viruses that threaten public and veterinary health have emerged or re-emerged in Europe. Mosquito surveillance activities have highlighted the Culex pipiens species complex as being critical for the maintenance of a number of these viruses. This species complex contains morphologically similar forms that exhibit variation in phenotypes that can influence the probability of virus transmission. Critical amongst these is the choice of host on which to feed, with different forms showing different feeding preferences. This influences the ability of the mosquito to vector viruses and facilitate transmission of viruses to humans and domestic animals. Biases towards blood-feeding on avian or mammalian hosts have been demonstrated for different Cx. pipiens ecoforms and emerging evidence of hybrid populations across Europe adds another level of complexity to virus transmission. A range of molecular methods based on DNA have been developed to enable discrimination between morphologically indistinguishable forms, although this remains an active area of research. This review provides a comprehensive overview of developments in the understanding of the ecology, behaviour and genetics of Cx. pipiens in Europe, and how this influences arbovirus transmission.
Su, T; Mulla, M S
Culiseta incidens Thomson is distributed over most of the western USA and Canada northward to Alaska. Because this mosquito is difficult to colonize, its biology has not been well investigated. We colonized this species in 1998 and studied the effects of temperature on various aspects of its life cycle. The time required for egg melanization and the duration of the egg stage were negatively correlated with temperature. The proportion of fertile egg rafts was temperature-independent. An inverse relationship existed between temperature and egg hatch. Molting and stadium duration after hatching were temperature-dependent, with higher temperature accelerating development and molting. Larvae and pupae experienced lower mortality and higher molting success at lower temperatures. Survivorship of adult mosquitoes fed on sugar solution was inversely proportional to temperature, lethal times for 50% mortality (LT50) were greater at the lower temperature than at the higher temperature. Females survived longer than did males at all test temperatures. Because this species is eurygamous, mating only occurred in large cages. Mating success was also affected by temperature. At the test temperatures, 20 degrees C, 25 degrees C and 30 degrees C, mating started from 3-5 days after emergence and reached a peak on days 13-15 after emergence. Maximum mating rates at 20 degrees C and 25 degrees C were higher than at 30 degrees C. Blood feeding, as indicated by cumulative feeding rates, was affected by cage size, mosquito age and temperature. Mosquitoes in large cages exhibited a much higher feeding rate than in small cages. With age, the cumulative blood feeding rate increased, with the highest rate at 25 degrees C, followed by 20 degrees C and 30 degrees C. At all temperatures tested, most of the blood fed females were mated.
Alencar, Jeronimo; Mello, Cecília Ferreira de; Gil-Santana, Hélcio R; Giupponi, Alessandro Ponce de Leão; Araújo, Andressa Nunes; Lorosa, Elias Seixas; Guimarães, Anthony Érico; Silva, Júlia Dos Santos
The stomach contents of culicids from the Atlantic Forest in Rio de Janeiro state, Brazil, were analyzed using the precipitin technique to evaluate the feeding patterns of the species. Sampling was performed from February 2012 to December 2013, using CO2-baited Centers for Disease Control and Prevention traps to catch mosquitoes from 15 00 to 07 00 hours. The following antisera were used: bird, rodent, opossum, human, horse, capybara, lizard, and frog. Of the 325 adult bloodfed females caught and analyzed, 273 (84.0%) reacted in the precipitin test. The percentage of specimens with a positive reaction to a single antiserum included bird (39.2%), rodent (22.5%), opossum (13.2%), capybara (6.6%), horse (5.7%), frog (6.2%), human (4.0%), and lizard (2.6%). The specimens that reacted positively against more than one blood source (46) most frequently presented the following combinations: bird + rodent and bird + frog (17.4%), followed by bird + human (13.0%). The predominance of positive results for birds suggested that the avian-rich environment might have influenced the feeding behavior of the culicids. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Kent, Rebekah; Juliusson, Lara; Weissmann, Michael; Evans, Sara; Komar, Nicholas
Studies on Culex tarsalis Coquillett in Colorado have shown marked seasonal variation in the proportion of blood meals from birds and mammals. However, limitations in the specificity of antibodies used in the precipitin test and lack of vertebrate host availability data warrant revisiting Cx. tarsalis blood feeding behavior in the context of West Nile virus (WNV) transmission. We characterized the host preference of Cx. tarsalis during peak WNV transmission season in eastern Colorado and estimated the relative contribution of different avian species to WNV transmission. Cx. tarsalis preferred birds to mammals each month, although the proportion of blood meals from mammals increased in July and August. The distribution of blood meals differed significantly across months, in part because of changes in the proportion of blood meals from American robins, a preferred host. The estimated proportion of WNV-infectious vectors derived from American robins declined from 60 to 1% between June and August. The majority of avian blood meals came from doves, preferred hosts that contributed 25-40% of the WNV-infectious mosquitoes each month. Active WNV transmission was observed in association with a large house sparrow communal roost. These data show how seasonal patterns in Cx. tarsalis blood feeding behavior relate to WNV transmission in eastern Colorado, with the American robin contributing greatly to early-season virus transmission and a communal roost of sparrows serving as a focus for late-season amplification.
Godoy, Raquel S M; Fernandes, Kenner M; Martins, Gustavo F
In most mosquito species, the females require a blood-feeding for complete egg development. However, in Toxorhynchites mosquitoes, the eggs develop without blood-feeding, and both females and males exclusively feed on sugary diets. The midgut is a well-understood organ in blood-feeding mosquitoes, but little is known about it in non-blood-feeding ones. In the present study, the detailed morphology of the midgut of Toxorhynchites theobaldi were investigated using histochemical and ultrastructural methods. The midgut of female and male T. theobaldi adults consists of a long, slender anterior midgut (AMG), and a short, dilated posterior midgut (PMG). The AMG is subdivided into AMG1 (short, with folds) and AMG2 (long, without folds). Nerve branches and enteroendocrine cells are present in AMG and PMG, respectively. Compared with the PMG of blood-feeding female mosquitoes, the PMG of T. theobaldi is smaller; however, in both mosquitoes, PMG seems be the main region of food digestion and absorption, and protein secretion. The epithelial folds present in the AMG of T. theobaldi have not been reported in other mosquitoes; however, the midgut muscle organization and endocrine control of the digestion process are conserved in both T. theobaldi and blood-feeding mosquitoes.
Rotraut A. G. B. Cônsoli
Full Text Available Observations were made on 100 female Aedes fluviatilis (Lutz maintained individually from the first blood meal onwards and allowed one blood meal during each oviposition cycle, 5% dextrose solution been supplied throughout life. The average length of live was 49.9 ± 17.8 days; the logarithm of the mortality rate increased proportionately to physiological age. The insects took an average of 7.3 ± 3.2 blood meals and produced a mean of 7.9 ± 3.7 clutches of eggs. There was a progressive decrease, proportional to advancing physiological age, in the mean numbers of eggs laid in successive oviposition cycles, in the intervals between blood feeding oviposition, and in the numbers of larvae that hatched. Delayed oviposition, transient sterility and a total loss of fertility were also recorded.De 100 fêmeas de Aedese fluviatilis (Lutz, 1904 individualmente observadas foram obtidos 45.475 ovos em um total de 790 posturas. As médias de desovas produzidas e de repastos sangüíneos ingeridos por fêmea, foram respectivamente 7,9 ± 3,7 e 7,3 ± 3,2 e a longevidade média foi de 49,9 ± 17,8 dias. Em análise de regressão linear, foi observado um progressivo decréscimo das médias de ovos por postura, larvas eclodidas e número de dias entre repasto sangüíneo e postura, proporcional ao aumento da idade fisiológica. Foram ainda observadas ocorrências de ingestão de sangue durante o desenvolvimento dos ovos, recusa de alimentação sangüínea entre desovas sucessivas, retenção espontânea de ovos por períodos apreciáveis, esterilidade transitória e esgotamento de fecundidade.
Godoy, Raquel S. M.; Fernandes, Kenner M.; Martins, Gustavo F.
In most mosquito species, the females require a blood-feeding for complete egg development. However, in Toxorhynchites mosquitoes, the eggs develop without blood-feeding, and both females and males exclusively feed on sugary diets. The midgut is a well-understood organ in blood-feeding mosquitoes, but little is known about it in non-blood-feeding ones. In the present study, the detailed morphology of the midgut of Toxorhynchites theobaldi were investigated using histochemical and ultrastructu...
Full Text Available Background: The aim of the current study was to develop a marking technique as an internal marker to mark post blood meal mosquitoes by using stable phosphate isotope 32P and determine the optimal concentration of it.Methods: An isotonic physiological saline solution, containing different concentration of radioactive isotope 32P-labeled disodium phosphate (Na2H32PO4 was injected into rabbits via the jugular vein in the laboratory. Emerged Cx. pipiens were marked after feeding on rabbit. At the same time, the labeled conditions of emerged Cx. pipiens were also measured by placing feces of No. 6 rabbit into containers with mosquito larvae and pupae inside.Results: According to the label condition of Cx. pipiens after taking blood and the effect of different dosage Na2H32PO4 on rabbit health, the optimal concentration of radioactive isotope was determined, that is, 0.1211 mCi/kg. By placing feces of No. 6 rabbit into containers with mosquito larvae and pupae inside, the emerged mosquitoes were also labeled. Therefore, feeding mosquitoes on the animal injected with radioactive Na2H32PO4 was more practical for detecting and tracing mosquitoes.Conclusion: The method was less time-consuming, more sensitive and safer. This marking method will facilitate post-bloodmeal studies of mosquitoes and other blood-sucking insects.
Damiens, D; Soliban, S M; Balestrino, F; Alsir, R; Vreysen, M J B; Gilles, J R L
The success of the sterile insect technique for the management of mosquito populations depends on the release of large numbers of competitive sterile male insects. Sustainable mosquito production can only be obtained when proper mass-rearing equipment and adequate methods are available, including those to feed blood to the female mosquitoes. The blood feeding apparatus Hemotek consists of a small aluminum plate to which a collagen membrane is fixed and filled with blood kept warm by an electric heating element. A larger aluminum plate was developed to feed a larger number of female mosquitoes with blood that is kept at a constant temperature. The effect of different blood feeding regimes (feeding frequency and time the blood is kept in the Hemotek) and sugar deprivation before blood feeding on egg production of female Anopheles arabiensis Patton was tested. Egg production was higher when blood was offered to the mosquitoes every day as compared with every 2 or 4 d. Sugar deprivation for 7 h before blood feeding enhanced egg production by 50% compared with female mosquitoes that had continuous access to sugar. Neither male nor female survival was impaired. Finally, we showed that the same blood could be kept warm and used over several hours to feed mosquitoes in multiple cages without any impact on egg production or hatch rate. Being able to use the same blood over extended periods would save considerable time, handling, and funds.
Kipyab Pamela C
Full Text Available Abstract Background Anopheles merus, a sibling species of the Anopheles gambiae complex occurs along the East African coast but its biology and role in malaria transmission in this region is poorly understood. We evaluated the blood feeding pattern and the role of this species in malaria transmission in Malindi district, Coastal Kenya. Methods Adult mosquitoes were collected indoors by CDC light traps and Pyrethrum Spray Catch and outdoors by CDC light traps. Anopheles females were identified to species by morphological characteristics and sibling species of An. gambiae complex distinguished by rDNA polymerase chain reaction (PCR. Screening for host blood meal sources and presence or absence of Plasmodium falciparum circumsporozoite proteins was achieved by Enzyme Linked Immunosorbent Assays (ELISA. Results Anopheles merus comprised 77.8% of the 387 Anopheles gambiae s.l adults that were collected. Other sibling species of Anopheles gambiae s.l identified in the study site included An. arabiensis(3.6%, and An. gambiae s.s. (8%. The human blood index for An. merus was 0.12, while the sporozoite rate was 0.3%. Conclusion These findings suggest that An. merus can play a minor role in malaria transmission along the Kenyan Coast and should be a target for vector control which in turn could be applied in designing and implementing mosquito control programmes targeting marsh-breeding mosquitoes; with the ultimate goal being to reduce the transmission of malaria associated with these vectors.
dos Santos Silva, Júlia; Alencar, Jeronimo; Costa, Janira Martins; Seixas-Lorosa, Elias; Guimarães, Anthony Érico
Feeding patterns of mosquitoes in six Brazilian environmental preservation areas were analyzed by the precipitin technique. The mosquito populations were captured using Shannon traps during different time periods. Bird, cow, dog, horse, opossum, human, and rodent antisera diagnostic tests were employed and results were analyzed by calculating the Sørensen similarity index and using the null-model test. Of the 647 analyzed specimens, 443 reacted to the utilized antisera, of which 331 reacted to one blood source, with the most frequent being birds (49.4%); and 112 specimens reacted to two blood sources, with the most frequent combination from birds + rodents (14.3%). The feed profiles demonstrated that Anopheles albitarsis, An. evansae, Aedes fulvus, Psorophora albigenu, Ps. albipes, Ps. ferox, and Mansonia titillans fed predominantly on birds. The similarity index showed that in some localities An. cruzii, Chagasia fajardi, Ae. scapularis, Ae. serratus, Haemagogus leucocelaenus, Ps. albigenu, and Ps. ferox presented similar dietary habits. The null-models test indicated that species from SMSP, INP, CGNP, and THP demonstrated an aggregate pattern, while species from SONP and SBNP showed a random pattern. The mosquitoes fed predominantly on birds, but from an epidemiological standpoint, the eclectic feeding habits were found to be constant among the mosquitoes analyzed. © 2012 The Society for Vector Ecology.
Philip Samuel, P; Arunachalam, N; Hiriyan, J; Tyagi, B K
Identification of blood meals of vector mosquitoes is an important tool in the epidemiological investigations of vector-borne diseases. The blood meals of three mosquito species involved in the transmission of Japanese encephalitis virus (JEV) from the Kuttanadu area, Kerala, were determined using the agarose gel diffusion technique. A total of 4959 blood smears belonging to Culex (Culex) tritaeniorhynchus Giles (3273), Cx. (Culex) gelidus Theobald (64), Mansonia (Mnd.) indiana Edwards (735) ,and Ma. (Mnd.) uniformis (Theobald) (887) were tested. Cx. tritaeniorhynchus had predominantly fed on bovids (46.4%), and a good proportion (29%) had fed on more than one host. Cx. tritaeniorhynchus was highly zoophagic, and human feeding accounted for only 1.5% of those individuals successfully tested. Cx. gelidus showed bovid feeding at 36% and pig feeding at 12.5%. The test results showed 42.3% Ma. indiana and 12.2% Ma. uniformis had fed on humans. Multiple feeding was observed in Ma. indiana and Ma. uniformis, and most of the double feedings were from bovids and ovids (7.9 and 20.1%, respectively). Pig feeding accounted for 4.8% of the feedings by Cx. tritaeniorhynchus, 5.3% of Ma. indiana, and 6.4% of Ma. uniformis. This study is significant because of the role played by these mosquitoes in the transmission of JEV in the Kuttanadu area of Kerala, India.
Hernández-Triana, Luis M.; Medlock, Jolyon M.; Fooks, Anthony R.; Carpenter, Simon; Johnson, Nicholas
Over the past three decades, a range of mosquito-borne viruses that threaten public and veterinary health have emerged or re-emerged in Europe. Mosquito surveillance activities have highlighted the Culex pipiens species complex as being critical for the maintenance of a number of these viruses. This species complex contains morphologically similar forms that exhibit variation in phenotypes that can influence the probability of virus transmission. Critical amongst these is the choice of host on which to feed, with different forms showing different feeding preferences. This influences the ability of the mosquito to vector viruses and facilitate transmission of viruses to humans and domestic animals. Biases towards blood-feeding on avian or mammalian hosts have been demonstrated for different Cx. pipiens ecoforms and emerging evidence of hybrid populations across Europe adds another level of complexity to virus transmission. A range of molecular methods based on DNA have been developed to enable discrimination between morphologically indistinguishable forms, although this remains an active area of research. This review provides a comprehensive overview of developments in the understanding of the ecology, behaviour and genetics of Cx. pipiens in Europe, and how this influences arbovirus transmission. PMID:29473903
Jonny E. Duque L.
Full Text Available Presentamos la construcción y la simulación de un modelo matemático, del tipo SIRS (SusceptibleInfeccioso Removido-Susceptible. Se utilizaron cuatro ecuaciones diferenciales para mostrar los parámetros más relevantes que deben ser seguidos en lucha contra vectores del dengue: θ (tasa de control cultural y ϕ (tasa de protección de los criaderos con la aplicación de tratamiento biológico o químico por un tiempo determinado, dentro del control de criaderos que influencian directamente el número de mosquitos que está relacionado con los aspectos ambientales representados por la función Sen2. Intengrando el control cultural y el tratamiento convencional, se puede mantener el número de criaderos en niveles bajos y con ello, la población de mosquitos. Debe utilizarse un control integrado para disminuir el número de criaderos de mosquitos y así reducir la cantidad de los mismos
Raúl Ernesto Campos
Full Text Available Egg hatching of winter-collected Ochlerotatus albifasciatus was studied for six months. Batches of eggs were divided into two groups, one of them was stored in the laboratory at 23°C and 12:12 photoperiod, and the other in the field under dead leaves. Every month, from July to December, eggs from the two groups were flooded under both laboratory and field conditions. Unhatched eggs were returned to the original condition and flooded two more times separated by ten-day intervals. Results show that egg diapause is expressed in different intensities, not only on eggs exposed to different conditions but also in those exposed to the same condition, even when they were laid by the same female. Successive inundations yielded incomplete hatches of eggs, and favored the hatching response in the next flooding. Low environmental temperatures before and during the flooding depressed hatching response. This shows that eggs need a warm period before flooding as well as warm temperatures during flooding, to hatch. As drought period was longer hatching response increased, but this was also accompanied by warmer environmental conditions. The experiment performed in laboratory did not show that increment. Field studies showed that a layer of dead leaves protected eggs from extreme temperatures.
Braima, Kamil A; Muslimin, M; M Ghazali, Amir-Ridhwan; Wan-Nor, F; Wilson, J J; Jeffery, J; Abdul-Aziz, N M
Mosquitoes are vectors of various human diseases in the tropics including yellow fever, dengue, malaria and West Nile virus. Mosquitoes can act as vectors between wildlife and humans, which is particularly important for diseases where wild animals serve as reservoirs of parasites in the absence of human infections. Research has mainly focused on the medical impacts of Anopheles, Aedes, Mansonia and Culex, however, very little attention has been directed towards other mosquito genera, especially those which act as vectors of diseases of wildlife. We have observed adults of Mimomyia (Etorleptiomyia) luzonensis (Ludlow, 1905) feeding on a toad, Ingerophrynus parvus, near an oil palm plantation settlement in Setia Alam, Selangor state, Peninsular Malaysia. Mimomyia is known to feed on reptiles and amphibians, and is a documented vector of several arboviruses, including West Nile virus. The observation of Mimomyia feeding on a common toad near a human settlement highlights a need to understand the relationships between mosquitoes, toads and humans from an ecological perspective. We report on-site observations of the feeding habit of Mimomyia; the first records from Malaysia. Copyright © 2017 Elsevier B.V. All rights reserved.
Mathew, G; Rai, K S
An ultrastructural study of mosquito ovarioles reveals that both the vitelline membrane and the endochorion are secreted by the follicular epithelium. The presecretory phase is characterized by the hypertrophy of endoplasmic reticulum and Golgi complex in the follicle cells. Synthesis of vitelline membrane precursors begins immediately after yolk protein uptake by micropinocytosis. Secretory droplets are budded off Golgi cisternae and released into the follicle cell--oocyte interface by exocytosis. The vitelline membrane first appears as dense plaques which eventually fuse to form a single homogeneous layer. Two types of secretory material are identified in the follicle cells prior to the formation of the endochorion. Golgi cisternae bud off small droplets similar in size and appearance to the precursors of the vitelline membrane. These migrate to the apical surface and accumulate between surface folds in the plasma membrane. The second type is a fibrous material formed in endoplasmic reticulum. When fully secreted, the endochorion is a 2-layered structure. The lower layer is comprised of pillar-like structures alternating with fibrous mesh-like areas. The pillars are formed by the coalescence of droplets released from Golgi, while the mesh-like areas presumably arise from the fibrous material. The outer layer is also fibrous. The follicle cells degenerate once the endochorion is laid down. endochorion is laid down.
Gaye, Alioune; Faye, Oumar; Diagne, Cheikh T; Faye, Ousmane; Diallo, Diawo; Weaver, Scott C; Sall, Amadou A; Diallo, Mawlouth
To investigate the potential for domestic and wild populations of Aedes aegypti from Dakar and Kedougou to develop a disseminated infection after exposure to DENV-3 and DENV-1. We have exposed sylvatic and urban population of Ae. aegypti from Senegal to bloomeals containing dengue serotype 1 and 3. At different incubation period, individual mosquito legs/wings and bodies were tested for virus presence using real time RT-PCR to estimate the infection and dissemination rates. The data indicated low susceptibility to DENV-3 (infection: 2.4-15.2%, and dissemination rates: 0-8.3%) and higher susceptibility to DENV-1 (infection and dissemination rates up to 50%). Aedes aegypti from Senegal seem able to develop a disseminated infection of DENV-1 and DENV-3. Further studies are needed to test their ability to transmit the two serotypes. © 2014 John Wiley & Sons Ltd.
Full Text Available Culex bidens and C. interfor, implicated in arbovirus transmission in Argentina, are sister species, only distinguishable by feature of the male genitalia; however, intermediate specimens of the species in sympatry have been found. Fourth-instar larvae and females of both species share apomorphic features, and this lack of clear distinction creates problems for specific identification. Geometric morphometric traits of these life stages also do not distinguish the species. The aim of the present study was to assess the taxonomic status of C. bidens and C. interfor using two mitochondrial genes and to determine the degree of their reproductive isolation using microsatellite loci. Sequences of the ND4 and COI genes were concatenated in a matrix of 993 nucleotides and used for phylogenetic and distance analyses. Bayesian and maximum parsimony inferences showed a well resolved and supported topology, enclosing sequences of individuals of C. bidens (0.83 BPP, 73 BSV and C. interfor (0.98 BPP, 97 BSV in a strong sister relationship. The mean K2P distance within C. bidens and C. interfor was 0.3% and 0.2%, respectively, and the interspecific variation was 2.3%. Bayesian clustering also showed two distinct mitochondrial lineages. All sequenced mosquitoes were successfully identified in accordance with the best close match algorithm. The low genetic distance values obtained indicate that the species diverged quite recently. Most morphologically intermediate specimens of C. bidens from Córdoba were heterozygous for the microsatellite locus GT51; the significant heterozygote excess observed suggests incomplete reproductive isolation. However, C. bidens and C. interfor should be considered good species: the ventral arm of the phallosome of the male genitalia and the ND4 and COI sequences are diagnostic characters.
Jéssica Barreto Lopes Silva
Full Text Available Dengue represents a serious threat to human health, with billions of people living at risk of the disease. Wolbachia pipientis is a bacterial endosymbiont common to many insect species. Wolbachia transinfections in mosquito disease vectors have great value for disease control given the bacterium's ability to spread into wild mosquito populations, and to interfere with infections of pathogens, such as dengue virus. Aedes fluviatilis is a mosquito with a widespread distribution in Latin America, but its status as a dengue vector has not been clarified. Ae. fluviatilis is also naturally infected by the wFlu Wolbachia strain, which has been demonstrated to enhance infection with the avian malarial parasite Plasmodium gallinaceum. We performed experimental infections of Ae. fluviatilis with DENV-2 and DENV-3 isolates from Brazil via injection or oral feeding to provide insight into its competence for the virus. We also examined the effect of the native Wolbachia infection on the virus using a mosquito line where the wFlu infection had been cleared by antibiotic treatment. Through RT-qPCR, we observed that Ae. fluviatilis could become infected with both viruses via either method of infection, although at a lower rate than Aedes aegypti, the primary dengue vector. We then detected DENV-2 and DENV-3 in the saliva of injected mosquitoes, and observed that injection of DENV-3-infected saliva produced subsequent infections in naïve Ae. aegypti. However, across our data we observed no difference in prevalence of infection and viral load between Wolbachia-infected and -uninfected mosquitoes, suggesting that there is no effect of wFlu on dengue virus. Our results highlight that Ae. fluviatilis could potentially serve as a dengue vector under the right circumstances, although further testing is required to determine if this occurs in the field.
Rotraut A. G. B. Consoli
Full Text Available Several larval and pupal products of Aedes fluviatilis (Lutz were tested for their influence on the oviposition behaviour of females of the same species. Significant (alfa = 0,05 atractiveness was shown by: larval water, previously containing 5 to 15 larvae/1,5 ml; larval water, preserved up to 38 days; evaporate and reconstructed larval water extracts up to 2 years after production and water filtered through fresh or dried ground larvae. hexanic larval water extracts and water filtered through fresh or dired ground pupae did not influence oviposition.Estudou-se a influência sobre o comportamento de oviposição das fêmeas de Aedes fluviatilis (Lutz de produtos derivados das formas imaturas da mesma espécie. As fêmeas foram atraídas significativamente (x=0,05 por ocasião da ovoposição por: água destilada que contivera 5 ou 15 larvas/1,5 ml, a mesma água (5 larvas/1,5 mlapós sua preservação por 38 dias; extratos evaporados e reconstituídos de água que conteve larvas, por até dois anos a sua produção, e filtrados de macerados frescos e secos de larvas. Extratos hexânicos de água que conteve larvas e filtrados de macerados descos e secos de pupas não atraíram a ovoposição das fêmeas.
Background Development rates of Aedes aegypti are known to vary with respect to many abiotic and biotic factors including temperature, resource availability, and intraspecific competition. The relative importance of these factors and their interactions are not well established across populations. We performed meta-analysis on a dataset of development rate estimates from 49 studies. Results Meta-analytic results indicated that the environmental factor of temperature is sufficient to explain development rate variability in Ae. aegypti. While diet and density may greatly impact other developmental phenotypes, these results suggest that for development rate these factors should never be considered to the exclusion of temperature. The effect of temperature on development rate is not homogenous or constant. The sources of heterogeneity of the effect of temperature are difficult to analyze due to lack of consistent reporting of larval rearing methods. Conclusions Temperature is the most important ecological determinant of development rate in Ae. aegypti, but its effect is heterogeneous. Ignoring this heterogeneity is problematic for models of vector population and vector-borne disease transmission. PMID:24495345
Essential oils are potential alternatives to synthetic insecticides because they have low mammalian toxicity, degrade rapidly in the environment, and possess complex mixtures of bioactive constituents with multi-modal activity against the target insect populations. Twenty one essential oils were ini...
Faull, Katherine J; Williams, Craig R
Aedes notoscriptus and Aedes aegypti are both peri-domestic, invasive container-breeding mosquitoes. While the two potential arboviral vectors are bionomically similar, their sympatric distribution in Australia is limited. In this study, analyses of Ae. aegypti and Ae. notoscriptus eggs were enabled using scanning electron microscopy. Significant variations in egg length to width ratio and outer chorionic cell field morphology between Ae. aegypti and Ae. notoscriptus enabled distinction of the two species. Intraspecific variations in cell field morphology also enabled differentiation of the separate populations of both species, highlighting regional and global variation. Our study provides a comprehensive comparative analysis of inter- and intraspecific egg morphological and morphometric variation between two invasive container-breeding mosquitoes. The results indicate a high degree of intraspecific variation in Ae. notoscriptus egg morphology when compared to the eggs of Ae. aegypti. Comparative morphological analyses of Ae. aegypti and Ae. notoscriptus egg attributes using SEM allows differentiation of the species and may be helpful in understanding egg biology in relation to biotope of origin. Copyright © 2016 Elsevier Ltd. All rights reserved.
Calvez, Elodie; Guillaumot, Laurent; Girault, Dominique; Richard, Vaea; O'Connor, Olivia; Paoaafaite, Tuterarii; Teurlai, Magali; Pocquet, Nicolas; Cao-Lormeau, Van-Mai; Dupont-Rouzeyrol, Myrielle
Dengue virus (DENV) is the arbovirus with the highest incidence in New Caledonia and in the South Pacific region. In 2012-2014, a major DENV-1 outbreak occurred in New Caledonia. The only known vector of DENV in New Caledonia is Aedes aegypti but no study has yet evaluated the competence of New Caledonia Ae. aegypti populations to transmit DENV. This study compared the ability of field-collected Ae. aegypti from different locations in New Caledonia to transmit the DENV-1 responsible for the 2012-2014 outbreak. This study also aimed to compare the New Caledonia results with the vector competence of Ae. aegypti from French Polynesia as these two French countries have close links, including arbovirus circulation. Three wild Ae. aegypti populations were collected in New Caledonia and one in French Polynesia. Female mosquitoes were orally exposed to DENV-1 (10 6 FFU/ml). Mosquito bodies (thorax and abdomen), heads and saliva were analyzed to measure infection, dissemination, transmission rates and transmission efficiency, at 7, 14 and 21 days post-infection (dpi), respectively. DENV-1 infection rates were heterogeneous, but dissemination rates were high and homogenous among the three Ae. aegypti populations from New Caledonia. Despite this high DENV-1 dissemination rate, the transmission rate, and therefore the transmission efficiency, observed were low. Aedes aegypti population from New Caledonia was less susceptible to infection and had lower ability to transmit DENV-1 than Ae. aegypti populations from French Polynesia. This study suggests that even if susceptible to infection, the New Caledonian Ae. aegypti populations were moderately competent vectors for DENV-1 strain from the 2012-2014 outbreak. These results strongly suggest that other factors might have contributed to the spread of this DENV-1 strain in New Caledonia and in the Pacific region.
Honorio, Nildimar A.
Toxorhynchites guadeloupensis (Dyar and Knab), a poorly known mosquito species, was observed preying upon Aedes aegypti (L.) larvae, in an oviposition trap placed for routine dengue entomological surveillance, during 2003-2004 in the urban area of Boa Vista, Roraima, Brazil. This is the first report for Tx. guadeloupensis using Ae. aegypti oviposition traps as breeding places. This finding may have important consequences in the epidemiology and local dengue control since Ae. aegypti density is a basic variable in dengue prediction. Whether predation of Ae aegypti by Tx. guadeloupensis in the Amazon is of significance, is a question to be examined. Also, larval predation may be a cause for underestimation of the actual Ae aegypti numbers. Together these hypotheses need to be better investigated as they are directly related to dengue epidemiology, to the success of any outbreak prediction and surveillance program. (author)
Combinations of female wingbeat acoustic cues and visual cues were evaluated to determine their potential for use in male Aedes aegypti (L.) traps in peridomestic environments. A modified Centers for Disease control (CDC) light trap using a 350-500 Hz frequency-sweep broadcast from a speaker as an a...
virus , chikungunya, Zika and Bouboui viruses have been isolated from Ae. africanus and Ae. opok in the Central African Republic (Germain et al., 1978...J., M. C. Williams, J. P. Woodall, D. I. H. Simpson, and L. K. H. Goma. 1964. Twelve isolations of Zika virus from Aedes (Stegomyiu) africanus...du Banco), Abidjan, Ivory Coast. Medical importance. -Unknown. However, Aedes africanus has been recog- nized as one of the most important virus
Full Text Available Culex quinquefasciatus is the vector responsible for serious disease filariasis among human beings. Plant derived products have received increased attention from scientists as they serve as a rich source for novel natural substances possessing insecticidal properties which are safe to human and ecosystem. During the last decade, various studies on natural plant products against vector mosquito indicate them as possible alternatives to chemical and synthetic insecticides for mosquito control. In the present study, the crude hexane and aqueous extract of Nerium oleander flowers were reported for larvicidal activity against the filarial vector, Culex quinquefasciatus. Mortality was observed for 24 and 48 hours. Hexane flower extract exhibited highest larvicidal activity with a LC50 value of 102.54 ppm and 61.11ppm after 24 and 48 hours respectively. Further investigations are needed to elucidate this activity against a wide range of all stages of mosquito species and also the active ingredient(s of the extract responsible for larvicidal activity should be identified.
To determine the ovicidal efficacy of different solvent leaf extracts of Ageratina adenophora against dengue vector Aedes aegypti . Methods: The ovicidal efficacy of the crude leaf extracts of A. adenophora with five different solvents (hexane, benzene, chloroform, ethyl acetate, methanol) and was ...
Mosquitoes are blood-feeding insects and serve as the most important vectors for spreading human diseases such as malaria, yellow fever, dengue fever, and filariasis. The continued use of synthetic insecticides has resulted in resistance in mosquitoes. Synthetic insecticides are toxic and affect the...
Six known thiophenes, 5-(3,4-diacetoxybut-1-ynyl)-2,2'-bithiophene (3), 2-(penta-1,3-diynyl)-5-(3,4-diacetoxybut-1-ynyl)thiophene (4), 5-(4-acetoxy-3-hydroxybut-1-ynyl)-2,2'-bithiophene (5), 2-(penta-1,3-diynyl)-5-(4-acetoxy-3-hydroxybut-1-ynyl)thiophene (6), 2-(penta-1,3-diynyl)-5-(3-acetoxy-4-hydr...
Mosquito-borne diseases with an economic impact create loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Extracts from plants may be alternativ...
Al Thbiani Aziz
Full Text Available Objective: To examine the insecticide susceptibility of Aedes aegypti (Ae. aegypti from various sites in Makkah City, Saudi Arabia. Methods: This was examined based on WHO standard procedures. Results: The larvae of Ae. aegypti were susceptible to all larvicides examined, but this susceptibility was more pronounced in wild populations, which tended to show tolerance to icon. Icon was the most effective larvicide with LC 50 values of 0.007 ppm and 0.012 ppm for the laboratory and field strains, respectively. Ae. aegypti adults exposed to lambda-cyhalothrin showed a low mortality rate in comparison with those exposed to deltamethrin and cyfluthrin. Conclusions: The results of the present study indicate differential susceptibility between field and laboratory larval populations. Wild larvae are less susceptible to insecticide treatments than their laboratory-bred counterparts. Taken together, these results suggest that tolerance and the tendency toward resistance to commonly used insecticides are present in Ae. aegypti populations throughout Makkah City, Saudi Arabia.
Full Text Available The objective of the present work was to determine the resistance levels to deltamethrine in two populations of Aedes aegypti from Peru. Bioassays in adults were carried out following the methodology of the World Health Organization. We met resistance in the Sullana population with 70% of mortality and susceptibility in the population The Future El Porvenir with 99% of mortality.
Carmen Elisa Posso
Full Text Available Random amplified polymorphic DNA (RAPD markers were used to analyze 119 DNA samples of three Colombian Anopheles nuneztovari populations to study genetic variation and structure. Genetic diversity, estimated from heterozygosity, averaged 0.34. Genetic flow was greater between the two populations located in Western Colombia (F ST: 0.035; Nm: 6.8 but lower between these two and the northeastern population (F ST: 0.08; Nm: 2.8. According to molecular variance analysis, the genetic distance between populations was significant (phiST 0.1131, P < 0.001. The variation among individuals within populations (phiST 0.8869, P < 0.001was also significant, suggesting a greater degree of population subdivision, not considered in this study. Both the parameters evaluated and the genetic flow suggest that Colombian An. nuneztovari populations are co-specific.
Full Text Available "nAbstract "nBackground: Culex pipiens complex shows variations in morphological and biological characters including different biological forms and has medical and veterinary importance. Because of having morphological variations, sometimes it is not easy to separate this species from Cx. quinquefasciatus and Cx. torrentium. The aim of this study was to identify the Culex pipiens complex species in order to use in control programs in the future. "nMethods: This study was carried out in two randomly selected rural villages in Yazd County, eastern Iran using dipping technique from April to October 2009. The data were analyzed using SPSS software version 16. "nResults: Average of siphon index in fourth-instrar larvae was 3.86±0.03, the minimum and maximum were calculated 2.43 and 5.14, respectively. Siphon/Saddle index was measured as average, minimum and maximum 3.2±0.2, 2.78, and 4.42 respectively. In our study, only 4 specimens had single seta 1 on segments III and VI (2.5% and the remaining beard double seta (97.5%. The maximum 3-6 branches seta 1a-S and 1b-S (95% were observed on siphon. "nConclusion: More populations of Culex pipiens from different areas of Iran need to be studied to gain complete information about the taxonomy and ecology of the species in the country. "n "nKeywords: Culex pipiens complex, larvae, taxonomy, Iran
Šebesta, Oldřich; Halouzka, Jiří; Hubálek, Zdeněk; Juřicová, Zina; Rudolf, Ivo; Šikutová, Silvie; Svobodová, Petra; Reiter, P.
Roč. 35, č. 1 (2010), s. 156-162 ISSN 1081-1710 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : mosquito es * Anopheles * Aedes * Culex * climate * ecology Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.256, year: 2010
Somers, Gerard; Brown, Julia E; Barrera, Roberto; Powell, Jeffrey R
Dengue viruses, primarily transmitted by the mosquito Aedes aegypti (L.), affect an estimated 50-100 million people yearly. Traditional approaches to control mosquito population numbers, such as the use of pesticides, have had only limited success. Atypical mosquito behavior may be one reason why current vector control efforts have been less efficacious than expected. In Puerto Rico, for example, adult Ae. aegypti have been observed emerging from septic tanks. Interestingly, adults emerging from septic tanks are larger on average than adults collected from surface containers. To determine whether adults colonizing septic tanks constitute a separate Ae. aegypti population, we used 12 previously validated microsatellite loci to examine adult mosquitoes collected from both septic tanks and surface containers, but found no evidence to suggest genetic differentiation. Size differences between septic tank and surface mosquitoes were reduced when nutrient levels were held constant across experimental groups. Despite the absence of evidence suggesting a genetic difference between experimental groups in this study, Ae. aegypti emerging from septic tanks may still represent a more dangerous phenotype and should be given special consideration when developing vector control programs and designing public health interventions in the future.
Smallegange, R.C.; Knols, B.G.J.; Takken, W.
Females of the African malaria vector, Anopheles gambiae Giles sensu stricto, use human volatiles to find their blood-host. Previous work has shown that ammonia, lactic acid, and aliphatic carboxylic acids significantly affect host orientation and attraction of this species, In the current study,
A field survey, three outdoor cage enclosure experiments, and laboratory studies were conducted to elucidate the impact of the invasive aquatic weeds Eichhornia crassipes (floating water hyacinth), Ludwigia hexapetala (emergent water yellow-primrose), and Egeria densa (submersed Brazilian waterweed)...
Full Text Available A preliminary study on larvicidal activity against laboratory-colonized Anopheles cracens mosquitos revealed that five of ten plant oils at concentration of 100 ppm showed 95–100% larval mortality. The essential oils of five plants, including Piper sarmentosum, Foeniculum vulgare, Curcuma longa, Myristica fragrans, and Zanthoxylum piperitum, were then selected for chemical analysis, dose-response larvicidal experiments, and combination-based bioassays. Chemical compositions analyzed by gas chromatography coupled to mass spectrometry demonstrated that the main component in the oil derived from P. sarmentosum, F. vulgare, C. longa, M. fragrans, and Z. piperitum was croweacin (71.01%, anethole (63.00%, ar-turmerone (30.19%, safrole (46.60%, and 1,8-cineole (21.27%, respectively. For larvicidal bioassay, all five essential oils exerted promising efficacy in a dose-dependent manner and different performances on A. cracens after 24 hours of exposure. The strongest larvicidal potential was established from P. sarmentosum, followed by F. vulgare, C. longa, M. fragrans, and Z. piperitum, with LC50 values of 16.03, 32.77, 33.61, 40.00, and 63.17 ppm, respectively. Binary mixtures between P. sarmentosum, the most effective oil, and the others at the highest ratio were proved to be highly efficacious with a cotoxicity coefficient value greater than 100, indicating synergistic activity. Results of mixed formulations of different essential oils generating synergistic effects may prove helpful in developing effective, economical, and ecofriendly larvicides, as favorable alternatives for mosquito management.
Barnard, D R
Laboratory bioassays assessed differences in the protection time provided by the repellent deet (N,N-diethyl-3-methylbenzamide) against 5-d-old nulliparous and 10-, 15-, and 20-d-old nulliparous and parous female Aedes aegypti (L.), Anopheles albimanus (Weidemann), and Anopheles quadrimaculatus Say sensu lato. Mean protection time was shortest against An. albimanus (1.6 h) and An. quadrimaculatus (1.5 h) and longest against Ae. aegypti (6.5 h), but was not significantly influenced by mosquito age or parity. Mean percentage of biting at repellent failure time was highest in An. albimanus (14.2%), followed by An. quadrimaculatus (7.0%) and Ae. aegypti (2.9%), was higher in parous females (10.8%) than in nulliparous females (5.9%), and was highest overall (35%) in 20-d-old parous An. albimanus. Interaction between mosquito species and parity and between parity and age factors, respectively, resulted from a significant decrease in percentage of biting by parous An. quadrimaculatus compared with other females, and a significant increase in biting by 20-d-old parous females compared with other females. The main finding of this study is that repellent protection time is unaffected by parity; this is important because parous mosquitoes are the primary target of personal-protection measures in disease-endemic areas. When repellent failure did occur, there was a higher risk of bite by old, parous An. albimanus than for any other species, age, or parity grouping of females.
Full Text Available Variations in the biology and ecology and the high level of genetic polymorphism of malaria vectors in Africa highlight the value of mapping their spatial distribution to enhance successful implementation of integrated vector management. The objective of this study was to collate data on the relative frequencies of Anopheles gambiae s.s. and An. arabiensis mosquitoes in Mali, to assess their association with climate and environmental covariates, and to produce maps of their spatial distribution. Bayesian geostatistical logistic regression models were fitted to identify environmental determinants of the relative frequencies of An. gambiae s.s. and An. arabiensis species and to produce smooth maps of their geographical distribution. The frequency of An. arabiensis was positively associated with the normalized difference vegetation index, the soil water storage index, the maximum temperature and the distance to water bodies. It was negatively associated with the minimum temperature and rainfall. The predicted map suggests that, in West Africa, An. arabiensis is concentrated in the drier savannah areas, while An. gambiae s.s. prefers the southern savannah and land along the rivers, particularly the inner delta of Niger. Because the insecticide knockdown resistance (kdr gene is reported only in An. gambiae s.s. in Mali, the maps provide valuable information for vector control. They may also be useful for planning future implementation of malaria control by genetically manipulated mosquitoes.
Full Text Available Objective: To get new data about the ecology of mosquitoes, which would be valuable to develop programs for future provision of mosquito controls in the study area. Methods: During April to September 2012, larvae of mosquitoes were collected from six counties in south of Fars Province using dipping method. Characteristics of larval breeding places were considered based on water conditions. Species diversity was examined in terms of alpha and beta measures, with the intent of comparing mosquito diversity according to the typology of regions. Results: During this investigation, totally, 5 057 larvae of mosquitoes belonging to 5 genera and 17 different mosquito species were recognized, namely, Anopheles dthali, Anopheles fluviatilis, Anopheles stephensi, Anopheles superpictus, Culex quinquefasciatus (Cx. quinquefasciatus, Culex mimeticus, Culex perexiguus, Culex pipiens (Cx. pipiens, Culex tritaeniorhynchus, Culex theileri (Cx. theileri, Culex tritaeniorhynchus, Culex sinaiticus, Culex torrentium, Culex modestus, Ochlerotatus caspius, Culiseta longiareolata and Aedes vexans (Ae. vexans. This is the first record of Ae. vexans, Culex perexiguus and Culex modestus in the Province. Cx. pipiens (27.3%, Cx. theileri (15.9% and Cx. quinquefasciatus (9.4% were the most abundant species found respectively. Cx. pipiens reached the highest density in August and July, while Cx. theileri, Cx. quinquefasciatus and Ae. vexans were found in high numbers in June. Diversity analysis indicated the highest species diversity in the Mohr County (Margalef index of 1.41 and Shannon index of 1.7 and the lowest species diversity in the Lamerd County (Margalef index of 0.33 and Shannon index of 0.38. Conclusions: Regarding to this research, there are some potential vectors of medical and veterinary importance in Fars Province. Results of the present study may serve as a basis for risk assessment of emerging mosquito-borne diseases.
of elephantiasis , with 83 Americans and 28 natives admitted during the year with dengue fever, No cases of malaria were known to have originated on...group, p. 109. Mosquito Systematics Vol. 8(4) 1976 -3e *South Pacific Conmission. 1951. Conference of experts on filariasis and elephantiasis . So
Eduardo S Bergo
Full Text Available Identification of Anopheles nuneztovari Gabaldón and An. goeldii Rozeboom and Gabaldón based on the male genitalia traits is discussed. An. goeldii is in the synonymy of An. nuneztovari, however, characters of the aedeagus of male genitalia distinguish both species. We hypothesize that An. goeldii may be a valid species, however, further studies using molecular characters, especially ITS2 rDNA sequences will be necessary to elucidate the taxonomic status of the species. An. konderi Galvão and Damasceno and An. forattinii Wilkerson and Sallum are registered for the first time in the state of Amapá.
condition . Both Y, and Y, are associated with species B and forms E and F; however, they show geographic variation. Chromosome Y, does not occur (or is...Heterochromatin and karyotypic differentiation of some Neotropical cactus-breeding species of the Drosophila replctu group. Genetica 60: 81-92
Allan, Sandra A; Bernier, Ulrich R; Kline, Daniel L
The role of lactic acid was evaluated for attraction of Culex nigripalpus, Culex quinquefasciatus, Culex tarsalis, and Aedes aegypti in the laboratory using a dual-port olfactometer. When lactic acid was combined with chicken odor, attraction was increased for Cx. quinquefasciatus compared to chicken odor alone but not for Cx. nigripalpus, Cx. tarsalis, and Ae. aegypti. Lactic acid combined with hand odor did not change attraction of Cx. tarsalis and Ae. aegypti but decreased attraction of Cx. nigripalpus and Cx. quinquefasciatus. The addition of lactic acid to CO(2) increased attraction of Ae. aegypti and Cx. quinquefasciatus but reduced attraction of Cx. nigripalpus and Cx. tarsalis. Use of commercial lactic acid baits with CO(2) resulted in a similar trend except for Cx. nigripalpus which showed no difference. A blend of lactic acid, acetone, and dimethyl disulfide was attractive to Ae. aegypti (63.4%) but elicited low responses by all Culex spp. (1.3-26.8%). Addition of the blend to CO(2) increased attraction of Ae. aegypti and Cx. quinquefasciatus but reduced attraction of Cx. nigripalpus and Cx. tarsalis. The mixture of compounds plus CO(2) was as attractive as a hand for Cx. quinquefasciatus, Cx. tarsalis, and Ae. aegypti. © 2010 The Society for Vector Ecology.
Ibañez-Justicia, Adolfo; Cianci, Daniela
Landscape modifications, urbanization or changes of use of rural-agricultural areas can create more favourable conditions for certain mosquito species and therefore indirectly cause nuisance problems for humans. This could potentially result in mosquito-borne disease outbreaks when the nuisance is caused by mosquito species that can transmit pathogens. Anopheles plumbeus is a nuisance mosquito species and a potential malaria vector. It is one of the most frequently observed species in the Netherlands. Information on the distribution of this species is essential for risk assessments. The purpose of the study was to investigate the potential spatial distribution of An. plumbeus in the Netherlands. Random forest models were used to link the occurrence and the abundance of An. plumbeus with environmental features and to produce distribution maps in the Netherlands. Mosquito data were collected using a cross-sectional study design in the Netherlands, from April to October 2010-2013. The environmental data were obtained from satellite imagery and weather stations. Statistical measures (accuracy for the occurrence model and mean squared error for the abundance model) were used to evaluate the models performance. The models were externally validated. The maps show that forested areas (centre of the Netherlands) and the east of the country were predicted as suitable for An. plumbeus. In particular high suitability and high abundance was predicted in the south-eastern provinces Limburg and North Brabant. Elevation, precipitation, day and night temperature and vegetation indices were important predictors for calculating the probability of occurrence for An. plumbeus. The probability of occurrence, vegetation indices and precipitation were important for predicting its abundance. The AUC value was 0.73 and the error in the validation was 0.29; the mean squared error value was 0.12. The areas identified by the model as suitable and with high abundance of An. plumbeus, are consistent with the areas from which nuisance was reported. Our results can be helpful in the assessment of vector-borne disease risk.
Blažejová, Hana; Šebesta, Oldřich; Rettich, F.; Mendel, Jan; Čabanová, V.; Miterpáková, M.; Betášová, Lenka; Peško, Juraj; Hubálek, Zdeněk; Kampen, H.; Rudolf, Ivo
Roč. 117, č. 1 (2018), s. 315-321 ISSN 0932-0113 R&D Projects: GA ČR(CZ) GA16-20054S Institutional support: RVO:68081766 Keywords : Anophelinae * Maculipennis complex * Anopheles daciae * Mosquitoes * Cryptic species * Vector-borne diseases Subject RIV: EG - Zoology Impact factor: 2.329, year: 2016
Calderón-Arguedas, Olger; Troyo, Adriana; Solano, Mayra E; Avendaño, Adrián; Beier, John C
Field studies were conducted to determine the mosquito species richness in the urban area of Greater Puntarenas in Costa Rica. Two cross-sectional entomological surveys were performed in seven localities of Puntarenas: one survey was performed during the wet season and the other during the dry season. The sections evaluated were determined by applying a stratified cluster sampling method using satellite imagery, and a sample of 26 cells (100 x 100m) was selected for the study. The number of cells per locality was proportional to the area of each locality. The presence of mosquito larvae and pupae in water-filled artificial and natural containers was determined in each cell. Infestation was expressed as a diversity index per type of container (Ii). Eight types of larvae were identified (Aedes aegypti, Culex quinquefasciatus, Culex interrogator, Culex nigripalpus, Culex corniger, Culex tarsalis, Limatus durhamii and Toxorhynchites theobaldi) and in two cases it was only possible to identify the genus (Culex sp. and Uranotaenia sp.). A. aegypti was the most common species followed by C. quinquefascitus. Diversity of wet environments can explain the co-occurrence of various culicid species in some localities. Although A. aegypti is the only documented disease vector in the area, C quinquefasciatus, C nigripalpus, and the other species of Culex could be considered potential vectors of other pathogens. The presence and ecology of all mosquito species should be studied to optimize surveillance and prevention of dengue and to prevent the emergence of other mosquito-transmitted diseases.
Endersby-Harshman, Nancy M; Wuliandari, Juli Rochmijati; Harshman, Lawrence G; Frohn, Verena; Johnson, Brian J; Ritchie, Scott A; Hoffmann, Ary A
Although pesticide resistance is common in insect vectors of human diseases, the evolution of resistance might be delayed if management practices are adopted that limit selection of resistance alleles. Outbreaks of dengue fever have occurred in Queensland, Australia, since the late 1800s, leading to ongoing attempts to control the mosquito vector, Aedes aegypti (L.). Since the 1990s, pyrethroid insecticides have been used for this purpose, but have been applied in a strategic manner with a variety of delivery methods including indoor residual spraying, lethal ovitraps, and use of insect growth regulators as larvicides. Separate selection experiments on mosquitoes from Queensland using Type I and Type II pyrethroids did not produce resistant lines of Ae. aegypti, and bioassays of field material from Queensland showed only weak tolerance in comparison with a susceptible line. There was no evidence of knockdown resistance (kdr) mutations in Ae. aegypti from Queensland, in stark contrast to the situation in nearby southeast Asia. We suspect that careful management of pyrethroid insecticide use combined with surveillance and interception of exotic incursions has helped to maintain pyrethroid (and particularly kdr-based) susceptibility in Ae. aegypti in Australia. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Gunathilaka, P A D H N; Uduwawala, U M H U; Udayanga, N W B A L; Ranathunge, R M T B; Amarasinghe, L D; Abeyewickreme, W
Larval diet quality and rearing conditions have a direct and irreversible effect on adult traits. Therefore, the current study was carried out to optimize the larval diet for mass rearing of Aedes aegypti, for Sterile Insect Technique (SIT)-based applications in Sri Lanka. Five batches of 750 first instar larvae (L 1) of Ae. aegypti were exposed to five different concentrations (2-10%) of International Atomic Energy Agency (IAEA) recommended the larval diet. Morphological development parameters of larva, pupa, and adult were detected at 24 h intervals along with selected growth parameters. Each experiment was replicated five times. General Linear Modeling along with Pearson's correlation analysis were used for statistical treatments. Significant differences (P rate and success, sex ratio, adult success, fecundity and hatching rate of Ae. aegypti. The best quality adults can be produced at larval diet concentration of 10%. However, the 8% larval diet concentration was most suitable for adult male survival.
Sarah Susanne Übleis
Full Text Available Information on mosquito-borne filarioid helminths in Austria is scarce, but recent discoveries of Dirofilaria repens indicate autochthonous distribution of this parasite in Eastern Austria. In the current xenomonitoring study, more than 48,000 mosquitoes were collected in Eastern Austria between 2013 and 2015, using different sampling techniques and storage conditions, and were analysed in pools with molecular tools for the presence of filarioid helminth DNA. Overall, DNA of D. repens, Setaria tundra, and two unknown filarioid helminths were documented in twenty mosquito pools within the mitochondrial cox1 gene (barcode region. These results indicate that S. tundra, with roe deer as definite hosts, is common in Eastern Austria, with most occurrences in floodplain mosquitoes (e.g., Aedes vexans. Moreover, DNA of D. repens was found in an Anopheles plumbeus mosquito close to the Slovakian border, indicating that D. repens is endemic in low prevalence in Eastern Austria. This study shows that xenomonitoring is an adequate tool to analyse the presence of filarioid helminths, but results are influenced by mosquito sampling techniques, storage conditions, and molecular protocols.
Full Text Available Abstract The search for new insecticides to control dengue fever, chikungunya, and Zika vectors has gained relevance in the past decades. The aim of the present study was to evaluate the larvicidal action of essential oils (EOs from Thymus vulgaris, Salvia officinalis, Lippia origanoides, Eucalyptus globulus, Cymbopogon nardus, Cymbopogon martinii, Lippia alba, Pelargonium graveolens, Turnera diffusa, and Swinglea glutinosa on Aedes (Stegomyia aegypti. The EOs were extracted by microwave-assisted hydrodistillation and characterized by gas chromatography/mass spectrometry (GC/MS. The chemical components of the EOs were identified by linear retention indices and mass spectra. Lethal concentrations (LC50 and LC95 were determined by probit analysis using larvae of Ae. aegypti between the third and the fourth instars. All EOs achieved larvicidal activity at LC50 values lower than 115 mg/L. The lowest LC50 value (45.73 mg/L corresponded to T. vulgaris EO, whereas C. martinii EO showed the highest LC50 (LC50 = 114.65 mg/L. Some EO mixtures showed lower LC50 than oils used individually, such as the mixtures of L. origanoides + S. glutinosa (LC50 = 38.40 mg/L, T. diffusa + S. glutinosa (LC50 = 63.71 mg/L, and L. alba + S. glutinosa (LC50 = 48.87 mg/L. The main compounds of the EOs with highest larvicidal activity were thymol (42% and p-cymene (26.4%.
Ebrahimi, Babak; Shakibi, Sanam; Foster, Woodbridge A
Mosquito eggs laid on water surfaces typically hatch spontaneously soon after the embryos within them become fully formed first-instar larvae. However, we have found that Anopheles gambiae Giles, an important vector of malaria in Africa, exhibits delayed hatching until the water surface is agitated, a feature overlooked in most laboratory colonies. Agitation within 24 h postoviposition, before embryonation was complete, failed to stimulate delayed postembryonic hatching of isolated eggs on the following day (day 2), when < 1% had hatched spontaneously. However, 5 min of water agitation of these dormant pharate first-instar larvae on day 2 resulted in an almost immediate hatch of 63.3 versus 0% of nonagitated controls, plus another 3.9 versus 0.3%, respectively, during the following 24 h. With daily agitation, installment hatching occurred mainly during 2-6 d postoviposition. The mean cumulative hatch after 7 d of daily agitation was 83.1 versus 1.1% of nonagitated eggs. Experiments with eggs in groups demonstrated that egg density and activity of already-hatched larvae had no stimulatory effect. Eggs stored 1-4 wk at 25.5 or at 15.5 degrees C, and then agitated daily for 6 d at 25.5 degrees C, showed a gradual decline in viability. Viability was sustained longer at the lower temperature. Implications of agitation-induced egg hatching for rainy-season and dry-season ecology of An. gambiae are discussed. Suspended hatching and cool storage already are proving convenient for efficient mass rearing and accurate modeling of weather-based population dynamics.
Tomberlin, Jeffery K.; Rains, Glen C.; Allan, Sandy A.; Sanford, Michelle R.; Lewis, W. Joe
The ability of many insects to learn has been documented. However, a limited number of studies examining associative learning in medically important arthropods has been published. Investigations into the associative learning capabilities of Culex quinquefasciatus Say were conducted by adapting methods commonly used in experiments involving Hymenoptera. Male and female mosquitoes were able to learn a conditioned stimulus that consisted of an odor not normally encountered in nature (synthetic strawberry or vanilla extracts) in association with an unconditioned stimulus consisting of either a sugar (males and females) or blood (females) meal. Such information could lead to a better understanding of the ability of mosquitoes to locate and select host and food resources in nature.
Gouagna, Louis-Clément; Poueme, Rodrigue S; Dabiré, Kounbobr Roch; Ouédraogo, Jean-Bosco; Fontenille, Didier; Simard, Frédéric
Sugar feeding by male mosquitoes is critical for their success in mating competition. However, the facets of sugar source finding under natural conditions remain unknown. Here, evidence obtained in Western Burkina Faso indicated that the distribution of An. gambiae s.s. (M and S molecular forms) males across different peri-domestic habitats is dependent on the availability of potential sugar sources from which they obtain more favorable sites for feeding or resting. Among field-collected anophelines, a higher proportion of specimens containing fructose were found on flowering Mangifera indica (Anacardiaceae), Dolonix regia (Fabaceae), Thevetia neriifolia (Apocynaceae), Senna siamea, and Cassia sieberiana (both Fabaceae) compared to that recorded on other nearby plants, suggesting that some plants are favored for use as a sugar source over others. Y-tube olfactometer assays with newly-emerged An. gambiae s.s. exposed to odors from individual plants and some combinations thereof showed that males use odor cues to guide their preference. The number of sugar-positive males was variable in a no-choice cage assay, consistent with the olfactory response patterns towards corresponding odor stimuli. These experiments provide the first evidence both in field and laboratory conditions for previously unstudied interactions between males of An. gambiae and natural sugar sources. © 2010 The Society for Vector Ecology.
Amal Elsayed Edriss
Full Text Available Certain mosquito species are important vectors of fatal human diseases, among which Anopheles arabiensis is known to be associated with malaria transmission in different tropical and subtropical areas. Since chemical control of mosquitoes was linked with numerous drawbacks, like resistance development, the search for effective environmentally sound alternatives is urgently needed. Therefore, it was aimed by this study to evaluate some extracts prepared from two asclepiadaceous plants, viz., Solenostemma argel “Hargel” (seeds and leaves and Calotropis procera “Usher” (leaves and flowers, as natural larvicides against An. arabiensis. The main parameters included bioassays of treatments for knockdown and residual effects, besides phytochemical analysis of the tested extracts. The results revealed variable groups of secondary metabolites in the two plants, with S. argel seemed to be the richest one. Hence, S. argel extracts caused higher larval mortalities than those of C. procera. This could be ascribed to some potent secondary metabolites in the former plant, which needs further studies. Almost all the high concentrations of S. argel extracts exerted the highest knockdown effect (90% mortality after 24 h, which were comparable with those obtained by two standard insecticides. The highest doses of petroleum ether and water extracts of this plant also manifested significantly higher residual effects than the other extracts after three days following treatments, but were surpassed by the chemical insecticides thereafter. However, S. argel seed petroleum ether extract at 0.5% was the most effective of all botanicals up to three weeks of exposure. This extract needs to be evaluated under field conditions for proper exploitation as mosquito larvicide.
Rita de Cássia Sousa-Polezzi
Full Text Available The effect of phenobarbital (PB on the induction of tolerance to the organophosphorous insecticide temephos (TE was investigated in Aedes aegypti L4 larvae submitted to two different PB-treatments:(1 continuous treatment from the egg to the larval L4 stage and (2 discontinuous treatment in which L4 larvae were exposed for 30 h. Mosquitoes from two Brazilian cities were studied: São José do Rio Preto (SJ in São Paulo State and Goiânia (GO in Goiás State. According to criterions established by World Health Organization (WHO mosquitoes from SJ are organophosphate-susceptible while mosquitoes from GO are organophosphate-resistant. For both SJ and GO larvae the two different PB-treatments resulted in significantly increased tolerance (measured by reduced mortality to 0.01mg/L TE while for larvae exposed to 0.02 mg/L TE only continuous PB-treatment resulted in significantly increased TE-tolerance. The reduction of mortality rate was greater in SJ larvae than in GO larvae, confirming data from other organisms indicating that the effect of PB is more pronounced in susceptible strains. To test if oxidase enzymes were involved in PB-induced tolerance we treated PB-pretreated SJ and GO larvae with the oxidase inhibitor piperonyl butoxide (PBO before exposure to TE and observed increased (rather than decreased tolerance, suggesting that oxidases are not involved in the tolerance process and that PB and PBO can act in concert or synergistically. Esterase patterns of PB-pretreated larvae indicated that the cholinesterases EST-13 and EST-14 are involved in the PB-induced TE- tolerance, reinforcing a previous study carried out in our laboratory which suggested that increased esterase synthesis is the mechanism responsible for the development of insecticide resistance in Aedes aegypti.
and Green 1987:256). maculosa James and Liston. 19I 1. Rattanarithikul and Green 1987:256 (lectotype 9 desig.- BM). Subgenus Nyssorhynchus Blanchard...1990:39 (2 syntypes, BM). campiorhynchus (Thomson) annulipes Taylor, 1914. Townsend 1990:42 (?3 syntypes; BM). detritus (Haliday) maculosa Theobald, 1905...Skuse, 195 misionensis Duret. 199 macu/at us Theobald. 181 moenensis Iyengar, 2 10 maculosa James and Liston, 183 mojuensis Duret and Damasceno. 200
Francisco F. Ludueña Almeida
Full Text Available Aedes albifasciatus is a flood water mosquito ocurring in the southern countries of South America. It is a competent vector of the Western Equine Encephalitis (WEE and causes important losses on milk and beef production in central Argentina. Field work was carried out from December 1990 to March 1993, on a monthly basis during the dry season and biweekly during the rainy season. Larvae were collected using the 'dipping' technique and females with CDC traps baited with CO2. Field collected larvae were used to build laboratory cohorts, from which basic population parameters were estimated. Eggs survived up to six months on dry soil, although there was a linear decrease of viability with time. At 23ºC, larval development time was around nine days, and all adults emerged within one week. The estimation of larval development in the laboratory seems to be very near the development on the field, as larvae have been collected on average eight days after a rainfall. Egg to adult survival was 83%, with the highest mortality on fourth larval instar (6%. In the laboratory studies, sex proportion among the adults was 1:1, females lived longer than males (median 13 and five days, respectively, and adult survival pattern showed a constant number of individuals dying per unit time. Field collected females layed an average of 84 eggs per batch, and completing up to five gonotrophic cycles, suggesting an estimated survival of up to 35-50 days.
Blažejová, Hana; Šebesta, Oldřich; Rettich, František; Mendel, Jan; Čabanová, Viktória; Miterpáková, Martina; Betášová, Lenka; Peško, Juraj; Hubálek, Zdeněk; Kampen, Helge; Rudolf, Ivo
We report the distribution of mosquitoes of the maculipennis complex in two distinct areas of the Czech Republic (Bohemia and South Moravia) and in one locality of neighbouring Slovakia with emphasis on the detection of the newly described cryptic species Anopheles daciae (Linton, Nicolescu & Harbach, 2004). A total of 691 mosquitoes were analysed using a species-specific multiplex PCR assay to differentiate between the members of the maculipennis complex. In the Czech Republic, we found Anopheles maculipennis (with a prevalence rate of 1.4%), Anopheles messeae (49.0%) and Anopheles daciae (49.6%). In Slovakia, only An. messeae (52.1%) and An. daciae (47.9%) were detected. In this study, An. daciae was documented for the first time in the two countries where it represented a markedly higher proportion of maculipennis complex species (with an overall prevalence almost reaching 50%) in comparison to previous reports from Germany, Romania and Poland. The determination of the differential distribution of maculipennis complex species will contribute to assessing risks of mosquito-borne diseases such as malaria or dirofilariasis.
termi- nalia and legs mounted; #NY 123-11 from Khaoyai. Five specimens came from Chiang Mai : #T-2195-10L and #T-2123-1P from Doi Sutep; #T-2413-lP...examined. The Thailand material contained 1 whole larva and 17 males with 9 associated larval and pupal skins from Chiang Mai ; 3 males, 2 with
genero Nyssorhynchus, corn especial referencia a morfologia dos ovos. Rev. Biol. Hyg. 9:51- 60. 1938b. Observacoes sobre o ciclo evolutivo de Anopheles...Vale do Paraiba. Nova variedade e ciclo evolutivo do Anofeles (Nyssorhynchus) osvaldoi var. ayrozai n. var. Ann. Paul. Med. Cir. 40:377-392. 1940b
Nyssorhynchus, corn especial referencia a morfologia dos ovos. Rev. Biol. Hyg. 9:51- 60. 1938b. Observacoes sobre o ciclo evolutivo de Anopheles oswaldoi...Anofelinos do Vale do Paraiba. Nova variedade e ciclo evolutivo do Anofeles (Nyssorhynchus) osvaldoi var. ayrozai n. var. Ann. Paul. Med. Cir. 40:377
signiÞcant disease and economic disruption. Rift Valley fever virus (RVFV), whichhasbeen responsible fornumerousoutbreaksof severe disease in ruminants and...is predominately a disease of domestic ruminants (cattle, goats, and sheep), where infection in pregnant animals usually results in abortion, and...www.cdc.gov/EID/ content /13/8/e1.htm). Britch, S.C.,K. J.Linthicum,A.Anyamba,C. J.Tucker,E.W. Pak, F. A. Maloney, K. Cobb, E. Stanwix, J. Humphries, A
Santa-Ana, Marta; Khadem, Manhaz; Capela, Ruben
Field and laboratory studies were performed to verify whether Culex theileri Theobald functions as a natural vector of Dirofilaria immitis (Leidy) on Madeira Island, Portugal. CO2-baited light traps (EVS traps) were use to sample mosquitoes monthly basis between February 2002 and February 2003 in the area of Quebradas (Funchal). Three mosquito species were captured, including 58 Culex pipiens L., 790 Cx. theileri, and three Culiseta longiareolata (Macquart). Only C. theileri tested positive for D. immitis. The presence of this filarial worm was detected by direct observation, infectivity assay dissection technique, and polymerase chain reaction methods. Infected mosquitoes were recovered in October and December 2002 and January 2003. These data provide evidence that Cx. theileri could be the main vector of D. immitis in Funchal, Madeira.
clans specimens in the Del -Mar-Va Peninsula (Buescher et al. J-920). The sig- nificance of these arbovirus isolations is discussed later. SYSTEMATIC...34EAH45", 5-VIII-1972, Rogers, 1L (UCLA), Belize: Sierra de Agua , IV-T.946, A. J. Walker, 29 (IJCLA). "BHA138", 1967, Mosq. Mid. Amer. 19 (UCLA), "BH366...highly acid Alabama swamp. The water had a high concentration of sulfate, sodium, potassium and ferrous ions as a result of contamination by a
Almirón Walter R.
Full Text Available Con el propósito de estudiar la preferencia de hospedadores vertebrados por mosquitos hembras, durante 2 períodos octubre-abril (primavera-verano, se realizaron muestreos cada 15 días en Córdoba y Cosquín (Argentina. Se utilizaron trampas de latón con cebo animal: anfibios (sapos, aves (pollos, mamíferos (conejos y reptiles (tortugas. El 92,9% de los especímenes recolectados pertenecen al género Culex, mientras que un 7,0% corresponde a Aedes y el 0,02% restante a Psorophora ciliata, única especie que se capturó de ese género. En trampas con pollo se recolectó el mayor número de hembras (68,7%, siguiendo en orden las trampas con conejos (29,9%, con tortugas (0,8% y con sapos (0,5%, por lo tanto, la mayoría de los mosquitos entraron en las trampas con hospedadores homeotermos. Culex dolosus se alimentó sobre todos los cebos, mientras que Cx. acharistus, Cx. chidesteri y Cx. quinquefasciatus se alimentaron sobre pollos, conejos y tortugas; Ae. albifasciatus, Ae. scapularis, Cx. bidens y Cx. coronator lo hicieron sobre ambos hospedadores homeotermos; Cx. apicinus, Cx. maxi, Cx. saltanensis y Cx. spinosus se alimentaron solamente sobre pollos y Ps. ciliata sobre conejos.
Miguel Alfonso Pacheco
Conclusions. We registered 11 new wing spot patterns in the costal vein and the dominance of the patterns I and VI for populations of An. darlingi from Colombia. We confirmed DSIII2/TaIII2 ratio as a robust diagnostic character for the taxonomy of this species. We found differences between the size and shape of the wings of An. darlingi populations in accordance to their geographical distribution, which constitute important bionomic aspects for this malaria vector.
Ondiaka, S.N.; Masinde, E.W.; Koenraadt, C.J.M.; Takken, W.; Mukabana, W.R.
Background The entomopathogenic fungus Metarhizium anisopliae shows great promise for the control of adult malaria vectors. A promising strategy for infection of mosquitoes is supplying the fungus at plant feeding sites. Methods We evaluated the survival of fungus-exposed Anopheles gambiae
The potential for gut microbiota to impede or enhance pathogen transmission is well-documented but the factors that shape this microbiota in mosquito vectors are poorly understood. We characterized and compared the gut microbiota of adult females of Culex restuans Theobald from different parents. Cu...
Pimenta Paulo FP
Full Text Available Abstract Background The insect gut harbors a variety of microorganisms that probably exceed the number of cells in insects themselves. These microorganisms can live and multiply in the insect, contributing to digestion, nutrition, and development of their host. Recent studies have shown that midgut bacteria appear to strengthen the mosquito's immune system and indirectly enhance protection from invading pathogens. Nevertheless, the physiological significance of these bacteria for mosquitoes has not been established to date. In this study, oral administration of antibiotics was employed in order to examine the contribution of gut bacteria to blood digestion and fecundity in Aedes aegypti. Results The antibiotics carbenicillin, tetracycline, spectinomycin, gentamycin and kanamycin, were individually offered to female mosquitoes. Treatment of female mosquitoes with antibiotics affected the lysis of red blood cells (RBCs, retarded the digestion of blood proteins and reduced egg production. In addition, antibiotics did not affect the survival of mosquitoes. Mosquito fertility was restored in the second gonotrophic cycle after suspension of the antibiotic treatment, showing that the negative effects of antibiotics in blood digestion and egg production in the first gonotrophic cycle were reversible. Conclusions The reduction of bacteria affected RBC lysis, subsequently retarded protein digestion, deprived mosquito from essential nutrients and, finally, oocyte maturation was affected, resulting in the production of fewer viable eggs. These results indicate that Ae. aegypti and its midgut bacteria work in synergism to digest a blood meal. Our findings open new possibilities to investigate Ae. aegypti-associated bacteria as targets for mosquito control strategies.
Mosquitoes of medical importance. U.S. Dep. Agric. Agric. Handb. 152. Forattini, O.P. 1962. Entomologia medica vol. I. Faculdade de Higiene e Saude Publica...meridional do Brasil. Rev. Saude Publ., S. Paulo. 21: 291-304. Forattini, O.P. 1962. Entomologia medica vol. I. Faculdade de Higiene e Saude...152. Forattini, O.P. 1962. Entomologia medica vol. I. Faculdade de Higiene e Saude Publica, Sao Paulo, Brazil. 662 pp. Grieco, J.P. 2001. The
Shah, Rizwan Mustafa; Ali, Qasim; Alam, Mehboob; Shad, Sarfraz Ali; Majeed, Shahid; Riaz, Muhammad; Binyameen, Muhammad
Culex quinquefasciatus Say is an important disease vector throughout much of the world. Experiments were conducted to determine the effects of different larval habitat substrates on the fitness and biting efficiency of Cx. quinquefasciatus adults. Our findings indicate that the development time (egg to adult) of larvae reared in irrigation water was 8.63 d while that of larvae reared in distilled water was 17.10 d (Effect size = 0.95). However, the rate of adult emergence was similar for all the tested treatments. Furthermore, the mean weight of an egg raft varied between larval habitats: distilled water (1.83 mg), rainfall water (1.25 mg), irrigation water (1.52 mg), and sewerage water (2.52 mg) (Effect size = 0.91). But, the fecundity (eggs per female) and hatchability (%) were statistically similar in all the rearing mediums (Effect size = 0.79). Longevity of females in all the tested populations did not differ significantly (Effect size = 0.91). The mean relative growth rates of larvae reared in tap water (0.80) and distilled water (0.86) habitats were lower than growth rates in all other rearing habitats (Effect size = 0.96). The intrinsic rate of natural increase in tap water (0.27) and irrigation water (0.35) was significantly higher than that in distilled water (0.09) and sewerage water (0.16) (Effect size = 0.84). Adults reared in rain water had the highest biting efficiency among all the tested populations. These results provide useful information for the management of Cx. quinquefasciatus. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Chitolina, R F; Anjos, F A; Lima, T S; Castro, E A; Costa-Ribeiro, M C V
The selection of oviposition sites by females of Aedes (Stegomyia) aegypti is a key factor for the larval survival and egg dispersion and has a direct influence in vector control programs. In this study, we evaluated the aspects of reproductive physiology of Ae. aegypti mosquitoes tested in the presence of raw sewage. Ae. aegypti females were used in oviposition bioassays according to two methodologies: (i) choice assay, in which three oviposition substrates were offered in the same cage: treatment (raw sewage), positive control (distilled water) and negative control (1% sodium hypochlorite) and; (ii) no choice assay, in which only one substrate was available. The physicochemical and microbiological analysis of the raw sewage used in this study indicated virtually no levels of chlorine, low levels of dissolved oxygen and high levels of nitrogenous compounds as well as the presence of Escherichia coli and total fecal coliforms. After 72h of oviposition, the eggs were counted and there was no statistically significant difference (p>0.05) in the oviposition rate between raw sewage and positive control in both methodologies. In addition, females were dissected to evaluate egg-retention and also there were no appreciable differences in egg retention even when raw sewage was the only substrate offered. The data also showed that egg hatching and larvae development occurred normally in the raw sewage. Therefore, the present study suggests that Ae. aegypti can adapt to new sites and lay eggs in polluted water, such as the raw sewage. These findings are of particular importance for the control and surveillance programs against Ae. aegypti in countries where the conditions of poor infrastructure and lack of basic sanitation are still an issue. Copyright © 2016 Elsevier B.V. All rights reserved.
Full Text Available Objective: To determine the adulticidal activity of hexane, benzene, chloroform, ethyl acetate and methanol leaf and seed extracts of Delonix elata (D. elata against Aedes aegypti (Ae. aegypti. Methods: The bioassay was conducted in an experimental kit consisting of two cylindrical plastic tubes both measuring 125 mm×44 mm following the WHO method; mortality of the mosquitoes was recorded after 24 h. Results: The adulticidal activity of plant leaf and seed extracts showed moderate toxic effect on the adult mosquitoes after 24 h of exposure period. However, the highest adulticidal activity was observed in the leaf methanol extract of D. elata against Ae. aegypti with the LC50 and LC90 values 162.87 and 309.32 mg/L, respectively. Conclusions: From this result, it can be concluded the crude extract of D. elata was an excellent potential for controlling Ae. aegypti mosquitoes.
Full Text Available Many environmental factors, biotic and abiotic interact to influence organismal development. Given the importance of Aedes aegypti as a vector of human pathogens including dengue and yellow fever, understanding the impact of environmental factors such as temperature, resource availability, and intraspecific competition during development is critical for population control purposes. Despite known associations between developmental traits and factors of diet and density, temperature has been considered the primary driver of development rate and survival. To determine the relative importance of these critical factors, wide gradients of conditions must be considered. We hypothesize that 1 diet and density, as well as temperature influence the variation in development rate and survival, 2 that these factors interact, and this interaction is also necessary to understand variation in developmental traits. Temperature, diet, density, and their two-way interactions are significant factors in explaining development rate variation of the larval stages of Ae. aegypti mosquitoes. These factors as well as two and three-way interactions are significantly associated with the development rate from hatch to emergence. Temperature, but not diet or density, significantly impacted juvenile mortality. Development time was heteroskedastic with the highest variation occurring at the extremes of diet and density conditions. All three factors significantly impacted survival curves of experimental larvae that died during development. Complex interactions may contribute to variation in development rate. To better predict variation in development rate and survival in Ae. aegypti, factors of resource availability and intraspecific density must be considered in addition, but never to the exclusion of temperature.
Soltani, Aboozar; Vatandoost, Hassan; Oshaghi, Mohammad Ali; Enayati, Ahmad Ali; Chavshin, Ali Reza
In the current study, the effects of the presence of symbiotic bacteria on the activity of the enzymes involved in An. stephensi resistance to temephos are evaluated for the first time. Four different strains (I. susceptible strain, II. resistant strain, III. resistant strain + antibiotic, and IV. resistant strain + bacteria) were considered in order to determine the possible effects of the symbiotic bacteria on their hosts' resistance to temephos. The median values of all enzymes of susceptible strain were compared with those of other resistant strains. The results of this study indicated a direct relationship between the presence of bacteria in the symbiotic organs of An. stephensi and resistance to temephos. The profile of enzymatic activities in the resistant strain changed to a susceptible status after adding antibiotic. The resistance of An. stephensi to temephos could be completely broken artificially by removing their bacterial symbionts in a resistant population.
Marcial Corrêa Cárcamo
Full Text Available Abstract: INTRODUCTION: We report the larvicidal activity of two formulations from Amanita muscariaagainst Culex quinquefasciatus, as well as the viability of the aqueous extract after storage. METHODS The larvicidal activity of aqueous extract and powder from A. muscaria, and the viability of the aqueous extract after storage, were evaluated. RESULTS The aqueous extract caused larval deaths, which varied from 16.4% to 88.4%. The efficiency of the powder varied from 29.2% to 82.8%. Storage did not interfere with the larvicidal efficiency of the aqueous extract of A. muscaria. CONCLUSIONS These results show the potential of A. muscariato control C. quinquefasciatus.
Honorio, Nildimar A. [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Dept. de Entomologia. Lab. de Transmissores de Hematozoarios; Barros, Fabio S.M. de [Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil). Centro de Ciencias Biologicas e da Saude. Nucleo Avancado de Vetores; Tsouris, Pantelis; Rosa-Freitas, Maria G. [Freitas and Tsouris Consultants, Spata-Attikis (Greece)]. E-mail: firstname.lastname@example.org
Toxorhynchites guadeloupensis (Dyar and Knab), a poorly known mosquito species, was observed preying upon Aedes aegypti (L.) larvae, in an oviposition trap placed for routine dengue entomological surveillance, during 2003-2004 in the urban area of Boa Vista, Roraima, Brazil. This is the first report for Tx. guadeloupensis using Ae. aegypti oviposition traps as breeding places. This finding may have important consequences in the epidemiology and local dengue control since Ae. aegypti density is a basic variable in dengue prediction. Whether predation of Ae aegypti by Tx. guadeloupensis in the Amazon is of significance, is a question to be examined. Also, larval predation may be a cause for underestimation of the actual Ae aegypti numbers. Together these hypotheses need to be better investigated as they are directly related to dengue epidemiology, to the success of any outbreak prediction and surveillance program. (author)
Turell, Michael J; Dohm, David J; Sardelis, Michael R; O 'Guinn, Monica L; Andreadis, Theodore G; Blow, Jamie A
.... To develop appropriate surveillance and control strategies, the identification of which mosquito species are competent vectors and how various factors influence their ability to transmit this virus must be determined...
species , but see Bourke et al . Genealogical analyses of complete mtDNA COI (Cyto- chrome oxidase I) sequences found that A. marajoara is...darlingi in human malaria transmission in Boa Vista, state of Roraima, Brazil. Mem Inst Oswaldo Cruz 2006, 101:163-168. 17. Bourke BP, Foster PG
Full Text Available Mosquitoes are vectors of several human pathogens, and great attention has recently been placed on insecticides from plant-derived products, in search for mosquito control agents. This study, thus, investigated the potency of Boswellia dalzielii methanol leaf extract and its four fractions as mosquito ovicide, larvicide, and pupicide against Anopheles gambiae and Culex quinquefasciatus . The plant products were tested at the following concentrations: 125, 250, 500, 1000, and 2000 ppm on eggs and 312.5, 625, 1250, and 2500 ppm on the larvae and pupae of the mosquitoes. For results, hatchability of A. gambiae eggs was reduced to 5% with n -hexane fraction at 2000 ppm. Among the plant products tested, n -hexane fraction was most toxic against A. gambiae (LC 50 = 385.9 ppm and C. quinquefasciatus (LC 50 = 3394.9 ppm. The n -hexane fraction of B. dalzielii might be used as a mosquitocidal agent in the breeding sites of A. gambiae and C. quinquefasciatus .
Al Ashry, Hamdy A; Kenawy, Mohamed A; Shobrak, Mohammed
An entomological survey was undertaken for one year to update the mosquito fauna of Asir Region, Kingdom of Saudi Arabia. A total of 31 species of 8 genera were reported of which genus Culex (55%) was the most common. Most of collected larvae (59%) belonged to genus Culex (+ Lutzia) followed by Culiseta (26%), Anopheles (13%) and Aedine spp. (2%). Cx. pipiens (39%) and Cs. longiareolata (26.%) were generally the most abundant of all collected larvae. Of the Anopheles spp., An. dthali was common (40%), of Culex spp., Cx. pipiens was predominating (66%) and of Aedine spp., St. aegypti was predominating (71%). Four species: An. fluviatilis, Cx. mattinglyi, Cx. arbieeni and Cx. mimeticus were new reports in Asir Region and Cx. wigglesworthi recorded for the first time from the kingdom. Larvae were more common in low- and highlands than in the moderately altitude areas. In general all species prefer stagnant water but with the exception of Aedine larvae (altogether), the other species prefer presence of algae, vegetation and shade and absence of turbidity (except Culex spp.). A total of 98 different forms of association were reported of which 9 forms were common. All genera breed year round with peaks of abundance during spring for Anopheles spp. and Culex spp. and during winter for Aedine spp. and Cs. longiareolata. A complete list of mosquito fauna of Asir Region comprising 45 spp. was presented based on the present and previous surveys. The study concluded that the occurrence and prevalence of mosquito species mainly the disease vectors in Asir carry the thread of maintaining and transmission of several mosquito-borne diseases.
María C Tranchida
Full Text Available Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cyclopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis Se hizo una prospección de copépodos en La Plata, Argentina, con los objetivos de caracterizar la comunidad local de copépodos larvívoros en sitios de cría de mosquitos, e identificar nuevas especies depredadoras de los mosquitos de contenedores artificiales Aedes aegypti y Culex pipiens. La diversidad de ciclopoides larvívoros fue máxima en charcos permanentes. Se examinó la depredación por sexos y edad, la selectividad por especies de mosquito, y la tasa de depredación diaria durante cinco días en Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus. Los copépodos hembra presentaron la capacidad depredadora más alta. No se encontró preferencia por alguna especie de mosquito. De acuerdo al potencial de depredación en general, los copépodos se ordenan así: D. uruguayensis < A. robustus < M. albidus < M. longisetus. También se evaluó la tolerancia a la desecación del hábitat y la capacidad de resistir en agua de contenedores artificiales. D. uruguayensis y A. robustus sobrevivieron en condiciones de sequía, pero D. uruguayensis presentó menor supervivencia en agua de floreros de cementerio. M. albidus no sobrevivió condiciones de sequía y no toleró el agua extraída de contenedores artificiales. Los ciclopoides neotropicales D. uruguayensis and A. robustus son buenos candidatos y merecen investigación ulterior como agentes de control biológico de mosquitos.
Maria Torres Olave
Full Text Available The mosquitoes distribution and the presence of arboviruses are determined by temperature, rainfall, geographic barriers, and other factors that determine the distribution of Culex spp. and can influence the human arboviral. The objective of this study was to identify potential spatial distribution of Culex spp. The ecological niche modeling was performed using MaxEnt Ecological niche modeling was performed using MaxEnt, bioclimatic variables (WorldClim used for this process are derived from the monthly values of temperature and precipitation to generate biologically significant variables (representing annual trends and limiting factors for the distribution of species. The resulting maps can be interpreted as relative suitability areas, these areas are presented on the east coast of Mexico, mainly in the states of Veracruz and Tabasco. The results show that Bio 2 (mean monthly temperature range, Bio 7 (annual range of temperature and Bio 11 (mean temperature of the coldest quarter, determine the highest percentage range. Distribution modeling Culex spp. It is an approach to identify the most vulnerable areas in Mexico. It is necessary to strengthen and establish multidisciplinary programs for the prevention ofCulexspp transmitted diseases.
1986. However, there have been few laboratory studies Container Volume. Eggs of Tx. amboinensis of the phenomenon. Rubio & Avesta (1984) sug- were...predator ratio and frequency of cannibalism, as competition for food may limit growth. Alterna- proposed by Rubio & Avesta (1984). A careful ex- tively, the
Heringer, Laila; Johnson, Brian J; Fikrig, Kara; Oliveira, Bruna A; Silva, Richard D; Townsend, Michael; Barrera, Roberto; Eiras, Álvaro E; Ritchie, Scott A
The Gravid Aedes Trap (GAT) uses visual and olfactory cues to attract gravid Aedes aegypti (L.) that are then captured when knocked down by a residual pyrethroid surface spray. However, the use of surface sprays can be compromised by poor availability of the spray and pesticide resistance in the target mosquito. We investigated several "alternative" insecticide and insecticide-free killing agents for use in the GAT. This included long-lasting insecticide-impregnated nets (LLINs), vapor-active synthetic pyrethroids (metofluthrin), canola oil, and two types of dry adhesive sticky card. During bench top assays LLINs, metofluthrin, and dry sticky cards had 24-h knockdown (KD) percentages >80% (91.2 ± 7.2%, 84.2 ± 6.8%, and 83.4 ± 6.1%, respectively), whereas the 24-h KD for canola oil was 70 ± 7.7%, which improved to 90.0 ± 3.7% over 48 h. Importantly, there were no significant differences in the number of Ae. aegypti collected per week or the number of traps positive for Ae. aegypti between the sticky card and canola oil treatments compared with the surface spray and LLIN treatments in semifield and field trials. These results demonstrate that the use of inexpensive and widely available insecticide-free agents such as those described in this study are effective alternatives to pyrethroids in regions with insecticide-resistant populations. The use of such environmentally friendly insecticide-free alternatives will also be attractive in areas where there is substantial resistance to insecticide use due to environmental and public health concerns. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Chin, A C; Chen, C D; Low, V L; Lee, H L; Azidah, A A; Lau, K W; Sofian-Azirun, M
This study was conducted using the glass chamber method to determine the susceptibility status of the dengue vector, Aedes aegypti (L.) from 11 states in Malaysia to commercial mosquito coils containing four different active ingredients, namely metofluthrin, d-allethrin, d-trans allethrin, and prallethrin. Aedes aegypti exhibited various knockdown rates, ranging from 14.44% to 100.00%, 0.00% to 61.67%, 0.00% to 90.00%, and 0.00% to 13.33% for metofluthrin, d-allethrin, d-trans allethrin, and prallethrin, respectively. Overall, mortality rates ranging from 0.00% to 78.33% were also observed among all populations. Additionally, significant associations were detected between the knockdown rates of metofluthrin and d-allethrin, and between metofluthrin and d-trans allethrin, suggesting the occurrence of cross-resistance within pyrethroid insecticides. Overall, this study revealed low insecticidal activity of mosquito coils against Ae. aegypti populations in Malaysia, and consequently may provide minimal personal protection against mosquito bites. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Juan C. Santana-Martínez
Full Text Available Aedes aegypti and Culex quinquefasciatus are mosquito vectors for several tropical diseases that represent a current public health problem. The ecological requirements for each species are different, however, both species show high biological adaptability, which promotes their coexistence in the same breeding sites. The purpose of this study was to assess the effect of larval association between Ae. aegypti and Cx. quinquefasciatus under different laboratory conditions of food supply and temperature, and under field simulated conditions like peridomestic containers. Our findings showed that under field simulated conditions there was no asymmetrical competition in mixed cultures with the different Cx. quinquefasciatus/Ae. aegypti ratios tested. However, under laboratory conditions in which different doses of food supply were evaluated, it was observed that competition between the two species takes place. Larval coexistence under food scarcity conditions (0.95 mg/larva showed that Ae. aegypti had a greater adult emergence than Cx. quinquefasciatus and was capable of depriving Cx. quinquefasciatus of the food needed to complete metamorphosis. In an intermediate dose of food (1.9 mg/larva, the dry weight of Cx. quinquefasciatus adults decreased, and their larval development time increased when Cx. quinquefasciatus/Ae. aegypti ratio was low. Also, a temperature effect was assessed demonstrating that Cx. quinquefasciatus was more vulnerable to changes in temperature. We suggest that Ae. aegypti is more successful in exploiting microhabitats when food is scarce, due to its scrape active feeding habitats and fast larval development times. Therefore, in conditions of food paucity both species will compete, and Ae. aegypti larvae will prevail.
Fang, Yuan; Shi, Wen-Qi; Zhang, Yi
The Anopheles hyrcanus group, which includes at least 25 species, is widely distributed in the Oriental and Palearctic regions. Some group members have been incriminated as vectors of malaria and other mosquito-borne diseases. It is difficult to identify Hyrcanus Group members by morphological features. Thus, molecular phylogeny has been proposed as an important complementary method to traditional morphological taxonomy. Based on the GenBank database and our original study data, we used 466 mitochondrial DNA COI sequences belonging to 18 species to reconstruct the molecular phylogeny of the Hyrcanus Group across its worldwide geographic range. The results are as follows. 1) The average conspecific K2P divergence was 0.008 (range 0.002-0.017), whereas sequence divergence between congroup species averaged 0.064 (range 0.026-0.108). 2) The topology of COI tree of the Hyrcanus Group was generally consistent with classical morphological taxonomy in terms of species classification, but disagreed in subgroup division. In the COI tree, the group was divided into at least three main clusters. The first cluster contained An. nimpe; the second was composed of the Nigerrimus Subgroup and An. argyropus; and the third cluster was comprised of the Lesteri Subgroup and other unassociated species. 3) Phylogenetic analysis of COI indicated that ancient hybridizations probably occurred among the three closely related species, An. sinensis, An. belenrae, and An. kleini. 4) The results supported An. paraliae as a probable synonym of An. lesteri, and it was possible that An. pseudopictus and An. hyrcanus were the same species, as evident from their extremely low interspecific genetic divergence (0.020 and 0.007, respectively) and their phylogenetic positions. In summary, we reconstructed the molecular phylogeny and analysed genetic divergence of the Hyrcanus Group using mitochondrial COI sequences. Our results suggest that in the future of malaria surveillance, we should not only pay much attention to those known vectors of malaria, but also their closely related species.
Faraj, C; Ouahabi, S; Adlaoui, E; Elaouad, R
This bibliographical study, based on published works, ministry of Health Reports, exploitation of the database relative to the entomological surveillance conducted in the framework of the National Malaria Control Program, as well as unpublished results obtained within the framework of the European project "Emerging disease in a changing European environment", summarizes and completes with new data current knowledge on the systematics, the distribution and the vectorial competence of moroccan anophelines. Copyright © 2010 Elsevier Masson SAS. All rights reserved.
Azubuike C. Ukubuiwe
Full Text Available The need to have an improved knowledge on the bioecology of Culex quinquefasciatus , a prerequisite in the development of cost-effective control strategies, has informed the present preliminary investigation to put in better perspective variations that exist in the egg rafts of the species. Freshly laid egg rafts were collected and incubated at ambient temperature in well-labeled plastic trays. The results showed overall inconsistency in all indices monitored for the egg rafts. Generally, survivorship was high for the species. All immature stage and adult parameters measured varied significantly among the egg rafts and between/within sexes of the species. Therefore, this study suggests the presence of inherent variation in the bionomics of egg rafts of C. quinquefasciatus , probably influenced by the environment and hence underscores the need for additional studies to further elucidate the roles of genetics and environment in vectorial competence of the species, in order to develop robust sustainable mosquito vector control protocols.
Wu, Tai-Ping; Tian, Jun-Hua; Xue, Rui-De; Fang, Yi-Liang; Zheng, Ai-Hua
In 2014, Guangzhou City, South China, suffered from its worst outbreak of dengue fever in decades. Larval mosquito habitat surveillance was carried out by using android mobile devices in four study sites in May 2015. The habitats with larval mosquitoes were recorded as photo waypoints in OruxMaps or in videos. The total number of potential mosquito habitats was 342, of which 166 (49%) were found to have mosquito larvae or pupae. Small containers were the most abundant potential habitats, accounting for 26% of the total number. More mosquito larvae and pupae, were found in small containers than in other objects holding water, for example, potted or hydroponic plants ( p Android mobile devices are a convenient and useful tool for surveillance of mosquito habitats, and the enhancement of source reduction may benefit the prevention and control of dengue vector mosquitoes.
Muturi, Ephantus J; Ramirez, Jose L; Doll, Kenneth M; Bowman, Michael J
Essential oils are potential alternatives to synthetic insecticides because they have low mammalian toxicity, degrade rapidly in the environment, and possess complex mixtures of bioactive constituents with multi-modal activity against the target insect populations. Twenty-one essential oils were initially screened for their toxicity against Aedes aegypti (L.) larvae and three out of the seven most toxic essential oils (Manuka, oregano, and clove bud essential oils) were examined for their chemical composition and combined toxicity against Ae. aegypti larvae. Manuka essential oil interacted synergistically with oregano essential oil and antagonistically with clove bud essential oil. GC-MS analysis revealed the presence of 21 components in Manuka essential oil and three components each in oregano and clove bud essential oils. Eugenol (84.9%) and eugenol acetate (9.6%) were the principal constituents in clove bud essential oil while carvacrol (75.8%) and m-isopropyltoluene (15.5%) were the major constituents in oregano essential oil. The major constituents in Manuka essential oil were calamenene (20%) and 3-dodecyl-furandione (11.4%). Manuka essential oil interacted synergistically with eugenol acetate and antagonistically with eugenol, suggesting that eugenol was a major contributor to the antagonistic interaction between Manuka and clove bud essential oils. In addition, Manuka interacted synergistically with carvacrol suggesting its contribution to the synergistic interaction between Manuka and oregano essential oils. These findings provide novel insights that can be used to develop new and safer alternatives to synthetic insecticides. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.
Gnankiné, Olivier; Bassolé, Imaël Henri Nestor
Widespread resistance of Anopheles sp. populations to pyrethroid insecticides has led to the search for sustainable alternatives in the plant kingdom. Among many botanicals, there is great interest in essential oils and their constituents. Many researchers have explored essential oils (EOs) to determine their toxicity and identify repellent molecules that are effective against Anopheles populations. Essential oils are volatile and fragrant substances with an oily consistency typically produced by plants. They contain a variety of volatile molecules such as terpenes and terpenoids, phenol-derived aromatic components and aliphatic components at quite different concentrations with a significant insecticide potential, essentially as ovicidal, larvicidal, adulticidal, repellency, antifeedant, growth and reproduction inhibitors. The current review provides a summary of chemical composition of EOs, their toxicity at different developmental stages (eggs, larvae and adults), their repellent effects against Anopheles populations, for which there is little information available until now. An overview of antagonist and synergistic phenomena between secondary metabolites, the mode of action as well as microencapsulation technologies are also given in this review. Finally, the potential use of EOs as an alternative to current insecticides has been discussed.
Full Text Available The purpose of the present study was to evaluate the larvicidal activity of leaf fractions of Annona senegalensis and Boswellia dalzielii against fourth instar larvae of Aedes aegypti. Fourth instar larvae of Ae. aegypti were exposed for 24 hours to various concentrations (312.5-2500 mg/L of methanolic crude extract and its fractions obtained with n-hexane, chloroform, ethyl-acetate and methanol solvents, following WHO method. The mortalities recorded were subjected to ANOVA test for mean comparison and Probit analysis to determine LC50. Preliminary phytochemical screening test for some components of the plants assessed were also evaluated. The phytochemical screening of the two plants revealed the presence of alkaloids, steroids, phenolic compounds, terpenoids, fats and oils in the crude extracts which, after splitting were most distributed in n-hexane and chloroform fractions. Apart from methanol fraction, all products used showed a significant (P<0.001 concentration-dependent toxicity against Ae. aegypti larvae. The LC50 recorded with crude extract were 759.6 and 830.4 mg/L for A. senegalensis and B. dalzielli respectively. After fractionation, n-hexane and chloroform fractions of A. senegalensis revealed more effective activity than others with CL50 values of 379.3 and 595.2 mg/L respectively. As for B. dalzielli, n-hexane (LC50=537.1 mg/L and chloroform (LC50=585.5 mg/L fractions were also the most effective. These results suggest that the n-hexane and chloroform fractions of these plants as a promising larvicide against Ae. aegypti and can constitute the best basic and vital step in the development of a botanical insecticide source.
specimens. bRange (Mode). TNTC-Too numerous to count. Table 3. Number of branches for setae of the fourth-instar larva of Aedes (Finlaya...2) 1,2(l) 1,2(2) 1,2(l) 1 2-4(2) 2,3(2) 7-ll(7) 1 1 1,2(l) aBased on counts from at least 10 setae on the holotype and 8 other specimens. bRange
Full Text Available Several important diseases are transmitted by mosquitoes. Despite of the potential of the occurrence of some mosquito-borne diseases such as West Nile, dirofilariasis and malaria in the region, there is no recent study of mosquitoes in West Azerbaijan Province. The aim of this investigation was to study the fauna, composition and distribution of mosquitoes and the characteristics of their larval habitats in this province.Larvae and adult collections were carried out from different habitats using the standard methods in twenty five localities of seven counties across West Azerbaijan Province.Overall, 1569 mosquitoes including 1336 larvae and 233 adults were collected from 25 localities. The details of geographical properties were recorded. Five genera along with 12 species were collected and identified including: Anopheles claviger, An. maculipennis s.l., An. superpictus, Culex pipiens, Cx. theileri, Cx. modestus, Cx. hortensis, Cx. mimeticus, Culiseta Longiareolata, Ochlerotatus caspius s.l., Oc. geniculatus and Uranotaenia unguiculata. This is the first record of Oc. geniculatus in the province.Due to the geographical location of the West Azerbaijan Province, it comprises different climatic condition which provides suitable environment for the establishment of various species of mosquitoes. The solidarity geographical, cultural and territorial exchanges complicate the situation of the province and its vectors as a threat for future and probable epidemics of mosquito-borne diseases.
Conn, Jan E.; Moreno, Marta; Saavedra, Marlon; Bickersmith, Sara A.; Knoll, Elisabeth; Fernandez, Roberto; Vera, Hubert; Burrus, Roxanne G.; Lescano, Andres G.; Sanchez, Juan Francisco; Rivera, Esteban; Vinetz, Joseph M.
Anopheline specimens were collected in 2011 by human landing catch, Shannon and CDC traps from the malaria endemic localities of Santa Rosa and San Pedro in Madre de Dios Department, Peru. Most specimens were either Anopheles (Nyssorhynchus) benarrochi B or An. (Nys.) rangeli, confirmed by polymerase chain reaction-restriction fragment length polymorphism-internal transcribed spacer 2 (PCR-RFLP-ITS2) and, for selected individuals, ITS2 sequences. A few specimens from Lupuna, Loreto Department, northern Amazonian Peru, were also identified as An. benarrochi B. A statistical parsimony network using ITS2 sequences confirmed that all Peruvian An. benarrochi B analyzed were identical to those in GenBank from Putumayo, southern Colombia. Sequences of the mtDNA COI BOLD region of specimens from all three Peruvian localities were connected using a statistical parsimony network, although there were multiple mutation steps between northern and southern Peruvian sequences. A Bayesian inference of concatenated Peruvian sequences of ITS2+COI detected a single clade with very high support for all An. benarrochi B except one individual from Lupuna that was excluded. No samples were positive for Plasmodium by CytB-PCR. PMID:23243107
Smithsonian Institution, Washington, DC 20560. ’ Ndcleo de Pesquisa Taxon6mica e Sistematica em Entomologia MBdica (NUPTEM), Departamento de Epidemiologia...anofelinos das regioes nordestinas e amazonica do Brasil. Rev. Serv. Esp. I: 827-965. Forattini, 0. P. 1962. Entomologia medica. vol. I. Parte Geral
Oswaldo Paulo Forattini
Full Text Available INTRODUÇÃO: O encontro de Aedes albopictus na cidade de Cananéia, região Sudeste do Estado de São Paulo, Brasil, ensejou a ocasião de realizar observações que visassem avaliar a produtividade de criadouro grande e permanente. Como objetivo, após selecionar o habitat a ser estudado, tentou-se avaliar-lhe a contribuição para a densidade local do mosquito. MATERIAL E MÉTODO: Em área predeterminada procedeu-se a levantamento de criadouros potenciais. Constatada a presença da espécie, foi selecionado um dos recipientes que preenchia os requisitos desejados. O acompanhamento foi feito de maneira ininterrupta, no período de novembro de 1996 a maio de 1997. As observações obdeceram a ritmo quinzenal retirando, cada vez, amostra da água correspondente a 0,14, ou seja, um sétimo do volume total de 70 litros. Procurou-se coletar, identificar e numerar, por sexo, as pupas existentes. Concomitantemente, procedeu-se à captura de formas adultas. Foi utilizada a isca humana das 15:00 às 18:00h, instalada a cerca de 6 metros do mencionado criadouro. Finda essa coleta, foi feita aspiração com 30 min. de duração em locais de abrigo representados pela abundante vegetação circunjacente. RESULTADOS: Nas coletas de formas imaturas do criadouro, o Ae. albopictus compareceu com 44,9%. Ao longo de 15 amostras regularmente realizadas obteve-se a média de 31,13 pupas pertencentes a essa espécie. O índice de emergência(E foi de 2,1. A multiplicação desse valor por sete forneceu a média diária de 14,7 fêmeas. Nas coletas de adultos desse sexo, a média de Williams para a isca humana foi de 30,7, enquanto a densidade média horária da aspiração dos locais de abrigo foi de 9,2. O cálculo do acúmulo diário concluiu pela presença de 22,8 fêmeas, por dia, capazes de freqüentar a isca humana, nessa situação e condições. DISCUSSÃO: A contagem de pupas possibilitou estimar a produtividade de criadouro de Ae. albopictus, tipo grande
Takken, W.; Jacobs, F.H.H.
Between September 2005 and October 2007 studies were done in six horticultural companies in the Netherlands to assess the presence of the exotic Aedes albopictus and to determine whether the species had become established. Adult mosquitoes were sampled with liberty plus carbon dioxide traps. The
Full Text Available The possibility of the rapid and global spread of Zika, chikungunya, yellow fever, and dengue fever by Aedes albopictus is well documented and may be facilitated by changes in climate. To avert and manage health risks, climatic and topographic information can be used to model and forecast which areas may be most prone to the establishment of Ae. albopictus. We aimed to weigh and prioritize the predictive value of various meteorological and climatic variables on distributions of Ae. albopictus in south-eastern Iran using the Analytical Hierarchy Process. Out of eight factors used to predict the presence of Ae. albopictus, the highest weighted were land use, followed by temperature, altitude, and precipitation. The inconsistency of this analysis was 0.03 with no missing judgments. The areas predicted to be most at risk of Ae. albopictus-borne diseases were mapped using Geographic Information Systems and remote sensing data. Five-year (2011–2015 meteorological data was collected from 11 meteorological stations and other data was acquired from Landsat and Terra satellite images. Southernmost regions were at greatest risk of Ae. albopictus colonization as well as more urban sites connected by provincial roads. This is the first study in Iran to determine the regional probability of Ae. albopictus establishment. Monitoring and collection of Ae. albopictus from the environment confirmed our projections, though on-going field work is necessary to track the spread of this vector of life-threatening disease.
Full Text Available BACKGROUND: The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities. METHODOLOGY/PRINCIPAL FINDINGS: In a series of experiments involving outdoors and indoors breeding populations, we found that Ae. albopictus lives longer in the indoor environment. We also observed increased nighttime biting activity and lifetime fecundity in indoor/domestic adapted females, although they were similar to recently colonized females in body size. CONCLUSION/SIGNIFICANCE: Taken together these data suggest that accommodation of Ae. albopictus to indoor/domestic environment may increase its lifespan, blood feeding success, nuisance and thus vectorial capacity (both in terms of increased vector-host contacts and vector population density. These changes in the breeding behavior of Ae. albopictus, a potential vector of several human pathogens including dengue viruses, require special attention.
Dieng, Hamady; Saifur, Rahman G M; Hassan, Ahmad Abu; Salmah, M R Che; Boots, Michael; Satho, Tomomitsu; Jaal, Zairi; AbuBakar, Sazaly
The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities. In a series of experiments involving outdoors and indoors breeding populations, we found that Ae. albopictus lives longer in the indoor environment. We also observed increased nighttime biting activity and lifetime fecundity in indoor/domestic adapted females, although they were similar to recently colonized females in body size. Taken together these data suggest that accommodation of Ae. albopictus to indoor/domestic environment may increase its lifespan, blood feeding success, nuisance and thus vectorial capacity (both in terms of increased vector-host contacts and vector population density). These changes in the breeding behavior of Ae. albopictus, a potential vector of several human pathogens including dengue viruses, require special attention.
Forattini Oswaldo Paulo
Full Text Available INTRODUÇÃO: O encontro de Aedes albopictus na cidade de Cananéia, região Sudeste do Estado de São Paulo, Brasil, ensejou a ocasião de realizar observações que visassem avaliar a produtividade de criadouro grande e permanente. Como objetivo, após selecionar o habitat a ser estudado, tentou-se avaliar-lhe a contribuição para a densidade local do mosquito. MATERIAL E MÉTODO: Em área predeterminada procedeu-se a levantamento de criadouros potenciais. Constatada a presença da espécie, foi selecionado um dos recipientes que preenchia os requisitos desejados. O acompanhamento foi feito de maneira ininterrupta, no período de novembro de 1996 a maio de 1997. As observações obdeceram a ritmo quinzenal retirando, cada vez, amostra da água correspondente a 0,14, ou seja, um sétimo do volume total de 70 litros. Procurou-se coletar, identificar e numerar, por sexo, as pupas existentes. Concomitantemente, procedeu-se à captura de formas adultas. Foi utilizada a isca humana das 15:00 às 18:00h, instalada a cerca de 6 metros do mencionado criadouro. Finda essa coleta, foi feita aspiração com 30 min. de duração em locais de abrigo representados pela abundante vegetação circunjacente. RESULTADOS: Nas coletas de formas imaturas do criadouro, o Ae. albopictus compareceu com 44,9%. Ao longo de 15 amostras regularmente realizadas obteve-se a média de 31,13 pupas pertencentes a essa espécie. O índice de emergência(E foi de 2,1. A multiplicação desse valor por sete forneceu a média diária de 14,7 fêmeas. Nas coletas de adultos desse sexo, a média de Williams para a isca humana foi de 30,7, enquanto a densidade média horária da aspiração dos locais de abrigo foi de 9,2. O cálculo do acúmulo diário concluiu pela presença de 22,8 fêmeas, por dia, capazes de freqüentar a isca humana, nessa situação e condições. DISCUSSÃO: A contagem de pupas possibilitou estimar a produtividade de criadouro de Ae. albopictus, tipo grande
Oswaldo Paulo Forattini
Full Text Available INTRODUÇÃO: O encontro de Aedes albopictus na cidade de Cananéia, região Sudeste do Estado de São Paulo, Brasil, ensejou a ocasião de realizar observações que visassem avaliar a produtividade de criadouro grande e permanente. Como objetivo, após selecionar o habitat a ser estudado, tentou-se avaliar-lhe a contribuição para a densidade local do mosquito. MATERIAL E MÉTODO: Em área predeterminada procedeu-se a levantamento de criadouros potenciais. Constatada a presença da espécie, foi selecionado um dos recipientes que preenchia os requisitos desejados. O acompanhamento foi feito de maneira ininterrupta, no período de novembro de 1996 a maio de 1997. As observações obdeceram a ritmo quinzenal retirando, cada vez, amostra da água correspondente a 0,14, ou seja, um sétimo do volume total de 70 litros. Procurou-se coletar, identificar e numerar, por sexo, as pupas existentes. Concomitantemente, procedeu-se à captura de formas adultas. Foi utilizada a isca humana das 15:00 às 18:00h, instalada a cerca de 6 metros do mencionado criadouro. Finda essa coleta, foi feita aspiração com 30 min. de duração em locais de abrigo representados pela abundante vegetação circunjacente. RESULTADOS: Nas coletas de formas imaturas do criadouro, o Ae. albopictus compareceu com 44,9%. Ao longo de 15 amostras regularmente realizadas obteve-se a média de 31,13 pupas pertencentes a essa espécie. O índice de emergência(E foi de 2,1. A multiplicação desse valor por sete forneceu a média diária de 14,7 fêmeas. Nas coletas de adultos desse sexo, a média de Williams para a isca humana foi de 30,7, enquanto a densidade média horária da aspiração dos locais de abrigo foi de 9,2. O cálculo do acúmulo diário concluiu pela presença de 22,8 fêmeas, por dia, capazes de freqüentar a isca humana, nessa situação e condições. DISCUSSÃO: A contagem de pupas possibilitou estimar a produtividade de criadouro de Ae. albopictus, tipo grande
Kathryn E Boes
Full Text Available The Asian tiger mosquito (Aedes albopictus is an important vector for pathogens that affect human health, including the viruses that cause dengue and Chikungunya fevers. It is also one of the world's fastest-spreading invasive species. For these reasons, it is crucial to identify strategies for controlling the reproduction and spread of this mosquito. During mating, seminal fluid proteins (Sfps are transferred from male mosquitoes to females, and these Sfps modulate female behavior and physiology in ways that influence reproduction. Despite the importance of Sfps on female reproductive behavior in mosquitoes and other insects, the identity of Sfps in Ae. albopictus has not previously been reported. We used transcriptomics and proteomics to identify 198 Sfps in Ae. albopictus. We discuss possible functions of these Sfps in relation to Ae. albopictus reproduction-related biology. We additionally compare the sequences of these Sfps with proteins (including reported Sfps in several other species, including Ae. aegypti. While only 72 (36.4% of Ae. albopictus Sfps have putative orthologs in Ae. aegypti, suggesting low conservation of the complement of Sfps in these species, we find no evidence for an elevated rate of evolution or positive selection in the Sfps that are shared between the two Aedes species, suggesting high sequence conservation of those shared Sfps. Our results provide a foundation for future studies to investigate the roles of individual Sfps on feeding and reproduction in this mosquito. Functional analysis of these Sfps could inform strategies for managing the rate of pathogen transmission by Ae. albopictus.
Walther, Doreen; Kampen, Helge
The citizen science project 'Mueckenatlas' (mosquito atlas) was implemented in early 2012 to improve mosquito surveillance in Germany. Citizens are asked to support the spatiotemporal mapping of culicids by submitting mosquito specimens collected in their private surroundings. The Mueckenatlas has developed into an efficient tool for data collection with close to 30,000 mosquitoes submitted by the end of 2015. While the vast majority of submissions included native mosquito species, a small percentage represented invasive species. The discovery of Aedes albopictus (Skuse) (Diptera: Culicidae), Aedes japonicus japonicus (Theobald) (Diptera: Culicidae) and Aedes koreicus (Edwards) (Diptera: Culicidae) specimens via the Mueckenatlas project prompted targeted monitoring activities in the field which produced additional information on the distribution of these species in Germany. Among others, Mueckenatlas submissions led to the detection of three populations of Ae. j. japonicus in West, North and Southeast Germany in 2012, 2013, and 2015, respectively. As demonstrated by on-site monitoring, the origins of Ae. j. japonicus specimens submitted to the Mueckenatlas mirror the distribution areas of the four presently known German populations as found by active field sampling (the fourth population already reported prior to the launch of the Mueckenatlas). The data suggest that a citizen science project such as the Mueckenatlas may aid in detecting changes in the mosquito fauna and can therefore be used to guide the design of more targeted field surveillance activities. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.
Full Text Available The primary vector at the origin of the 2007 outbreak in Libreville, Gabon is identified as Aedes albopictus, trapped around the nearby French military camp. The Chikungunya virus was isolated from mosquitoes and found to be identical to the A226V circulating human strain. This is the first field study showing the role of the recently arrived species Aedes albopictus in Chikungunya virus transmission in Central Africa, and it demonstrates this species' role in modifying the epidemiological presentation of Chikungunya in Gabon.
Higa, Yukiko; Yen, Nguyen Thi; Kawada, Hitoshi; Son, Tran Hai; Hoa, Nguyen Thuy; Takagi, Masahiro
The spatial distribution of Aedes aegypti and Aedes albopictus in environmental and geographical zones, e.g., urban-rural, coastal-mountainous, and north-south, was investigated throughout Vietnam. Immature stages were collected from used tires along roads. The effects of regions, seasons, and the degree of urbanization on the density and the frequency were statistically analyzed. Aedes aegypti predominated in the southern and central regions, while Ae. albopictus predominated in the northern region, which may be related to climatic conditions (temperature and rainfall). Larval collection from used tires may be suitable to assess rapidly the current distribution of dengue mosquitoes for estimating health risks and implementing vector control measures.
Bagny Beilhe, L; Delatte, H; Juliano, S A; Fontenille, D; Quilici, S
Two invasive, container-breeding mosquito species, Aedes aegypti (Stegomyia aegypti) and Aedes albopictus (Stegomyia albopicta) (Diptera: Culicidae), have different distribution patterns on Reunion Island. Aedes albopictus occurs in all areas and Ae. aegypti colonizes only some restricted areas already occupied by Ae. albopictus. This study investigates the abiotic and biotic ecological mechanisms that determine the distribution of Aedes species on Reunion Island. Life history traits (duration of immature stages, survivorship, fecundity, estimated finite rate of increase) in Ae. aegypti and Ae. albopictus were compared at different temperatures. These fitness measures were characterized in both species in response to competitive interactions among larvae. Aedes aegypti was drastically affected by temperature, performing well only at around 25 °C, at which it achieved its highest survivorship and greatest estimated rate of increase. The narrow distribution of this species in the field on Reunion Island may thus relate to its poor ability to cope with unfavourable temperatures. Aedes aegypti was also more negatively affected by high population densities and to some extent by interactions with Ae. albopictus, particularly in the context of limited food supplies. Aedes albopictus exhibited better population performance across a range of environmental conditions. Its ecological plasticity and its superior competitive ability relative to its congener may further enhance its invasion success on Reunion Island. © 2012 The Royal Entomological Society.
Ayllón, Tania; Câmara, Daniel Cardoso Portela; Morone, Fernanda Cristina; Gonçalves, Larissa da Silva; Saito Monteiro de Barros, Fábio; Brasil, Patrícia; Carvalho, Marilia Sá; Honório, Nildimar Alves
Aedes albopictus, originally considered as a secondary vector for arbovirus transmission, especially in areas where this species co-exist with Aedes aegypti, has been described in most regions of the world. Dispersion and domiciliation of Ae. albopictus in a complex of densely urbanized slums in Rio de Janeiro, Southeastern Brazil, was evidenced. In this study, we tested the hypotheses that 1) Ae. albopictus distribution in urban slums is negatively related to distance from vegetation, and 2) these vectors have taken on a domestic life style with a portion of the population feeding, ovipositing, and resting indoors. To do this, we developed an integrated surveillance proposal, aiming to detect the presence and abundance of Aedes mosquitoes. The study, based on a febrile syndrome surveillance system in a cohort of infants living in the slum complex, was performed on a weekly basis between February 2014 and April 2017. A total of 8,418 adult mosquitoes (3,052 Ae. aegypti, 44 Ae. albopictus, 16 Ae. scapularis, 4 Ae. fluviatilis and 5,302 Culex quinquefasciatus) were collected by direct aspiration and 46,047 Aedes spp. eggs were collected by oviposition traps. The Asian tiger mosquito, Ae. albopictus, was aspirated in its adult form (n = 44), and immature forms of this species (n = 12) were identified from the eggs collected by the ovitraps. In most collection sites, co-occurrence of Ae. aegypti and Ae. albopictus was observed. Key-sites, such as junkyards, thrift stores, factories, tire repair shops and garages, had the higher abundance of Ae. albopictus, followed by schools and households. We collected Ae. albopictus at up to 400 meters to the nearest vegetation cover. The log transformed (n+1) number of females Ae. albopictus captured at each collection point was inversely related to the distance to the nearest vegetation border. These results show that Ae. albopictus, a competent vector for important arboviruses and more commonly found in areas with higher
Full Text Available A German traveler developed dengue fever in late August 2013, following a direct flight from Germany. Autochthonous dengue virus (DENV infection has not been reported in Japan. To evaluate the risk of autochthonous DENV transmission in Japan, the authors performed a retrospective search of the five areas visited by the German patient to determine the population density of dengue vector mosquito, Aedes albopictus. The annual mean temperature of each area was higher than 12 °C, which is considered suitable for the establishment of A. albopictus populations. Our retrospective search revealed the population density of A. albopictus to be high in the urban areas of Japan.
Misni, Norashiqin; Sulaiman, Sallehudin; Othman, Hidayatulfathi; Omar, Baharudin
The repellent activity of Piper aduncum essential oil against Aedes albopictus was investigated under laboratory conditions with human volunteers. The lowest median effective dose (ED50) value was 1.5 microg/cm2 at 60 sec of exposure when compared to 90 sec (2.1 microg/cm2) and 120 sec (1.8 microg/cm2) of exposure. At 0.4 g, the essential oil gave a high protection (95.2%) against Ae. albopictus bites or landing at 2 h postapplication. The percentage of protection was reduced to 83.3% after 4 h, 64.5% after 6 h, and 51.6% after 8 h postapplication. As a comparison, treatment with 10% deet gave 100% protection against mosquito biting/landing for 4 h postapplication. There was no significant difference in percentage protection reduction between the plant extract and the commercial product deet, respectively (P = 0.739). The essential oil, which was not as good as deet, still gave moderate protection against Ae. albopictus biting even until 4 h postapplication. In conclusion, the P. aduncum essential oil has the potential to be used as a repellent against the dengue/dengue hemorrhagic fever vector, Ae. albopictus.
Doyle, Melissa A; Kline, Daniel L; Allan, Sandra A; Kaufman, Phillip E
The daytime biting mosquito Aedes albopictus is a nuisance pest commonly found in suburban yards. The recommended course of treatment for Ae. albopictus is to keep yards free of water-holding containers; however, infestations may require additional control methods such as residual pesticide applications to vegetation. Five plants commonly found in yards or in uncultivated areas in Gainesville, FL were chosen as substrates for evaluation of the effectiveness of residual bifenthrin against 5-7-day-old female Ae. albopictus. Knockdown of mosquitoes after 1 h of exposure was highest the day of and 7 days after treatment. Plant species clearly impacted the effectiveness of residual bifenthrin. One-hour knockdown 7 days after treatment remained high (>62%) only on azalea and holly bush vegetation. Knockdown counts 24 h after exposure demonstrated that residual efficacy of bifenthrin was highest on azalea, with >77% mortality for up to 35 days. Additional bioassays revealed significant differences in the knockdown rates of male, female, gravid, and blood-fed Ae. albopictus exposed to residual bifenthrin treatments, with the highest knockdown observed on the day of and 7 days after treatment.
Fontenille, D.; Toto, J. C.
Aedes albopictus, a mosquito vector of Dengue virus, has been recorded for the first time in Cameroon. Entomologic surveys in 2000 demonstrated that it is widespread in southern Cameroon, colonizing a wide variety of breeding sites and biting humans in every district surveyed. The presence of this vector increases the risk for emergence of dengue in Cameroon.
Aedes albopictus is an invasive species. Its oviposition behavior is the subject of several projects in our research unit. The main emphasis of this presentation is a study which utilizes two five gallon buckets, one heated and one with ambient temperature. The heat is provided by an aquarium hea...
Rachael K Walsh
Full Text Available Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation.
Scholte, E.J.; Takken, W.
In the summer of 2005, the Asian tigermosquito (Aedes albopictus) was found for the first time in the Netherlands. It was intercepted in several horticultural companies that import the ornamental plant Lucky bamboo from southern China, an endemic area for this mosquito species. The current report
Misni, Norashiqin; Sulaiman, Sallehudin; Othman, Hidayatulfathi; Omar, Baharudin
The repellent activity of Piper aduncum essential oil against Aedes albopictus was investigated under laboratory conditions with human volunteers. The lowest median effective dose (ED(50)) value was 1.5 mu g/cm(2) at 60 sec of exposure when compared to 90 see (2.1 mu g/cm(2)) and 120 see (1.8 mu
The Asian tiger mosquito, Aedes albopictus, ranks among the most important vectors of dengue fever, Zika virus, and chikungunya virus. With no specific medications or vaccines available, vector control is the only way to combat these diseases. Autodissemination of the insect growth regulator pyripro...
Goubert, C; Minard, G; Vieira, C; Boulesteix, M
The Asian tiger mosquito Aedes albopictus is currently one of the most threatening invasive species in the world. Native to Southeast Asia, the species has spread throughout the world in the past 30 years and is now present in every continent but Antarctica. Because it was the main vector of recent Dengue and Chikungunya outbreaks, and because of its competency for numerous other viruses and pathogens such as the Zika virus, A. albopictus stands out as a model species for invasive diseases vector studies. A synthesis of the current knowledge about the genetic diversity of A. albopictus is needed, knowing the interplays between the vector, the pathogens, the environment and their epidemiological consequences. Such resources are also valuable for assessing the role of genetic diversity in the invasive success. We review here the large but sometimes dispersed literature about the population genetics of A. albopictus. We first debate about the experimental design of these studies and present an up-to-date assessment of the available molecular markers. We then summarize the main genetic characteristics of natural populations and synthesize the available data regarding the worldwide structuring of the vector. Finally, we pinpoint the gaps that remain to be addressed and suggest possible research directions. PMID:27273325
Phospholipase A2 (PLA2) is a secretory digestive enzyme that hydrolyzes ester bond at sn-2 position of dietary phospholipids, creating free fatty acid and lysophopholipid. The free fatty acids (arachidonic acid) are absorbed into midgut cells. Aedes albopictus and Culex quinquefasciatus digestive PL...
The radiosensitivity of the line of Aedes albopictus cells was investigated by scoring x-ray-induced chromosome aberrations as a function of dose and of time after irradiation as well as the modification by dose fractionation. In order to obtain these data, a series of studies, e.g., karyotype, cell life cycle, radiation- induced mitotic delay, and frequency and type of spontaneous aberrations, were carried out. Cells from this line had three pairs of chromosomes as a stem line chromosome number. The morphology of the chromosomes is metacentric. Somatic pairing between homologous chromosomes was observed as a common event and there was a high frequency of achromatic gaps on the chromosomes. These observations are in good agreement with those made in other laboratories. The generation time of A. albopictus cell line was approximately 32 hours, in which G 1 , S, and G 2 phases were 2 1 / 2 , 24 and 5 1 / 2 hours respectively. This generation time is in agreement with the population doubling time observed in our cell growth studies. By contrast, in most mammalian cells, G 1 usually is the longest phase and S is comparatively short. Dose fractionation studies indicated that A. albopictus cells in culture may have a faster chromosome repair system than mammalian and other cell systems. This may, at least in part; explain the difference in radiosensitivity between A. albopictus cell line and other cell systems. (Diss. Abstr.)
Ciota, Alexander T; Bialosuknia, Sean M; Ehrbar, Dylan J; Kramer, Laura D
To determine the potential role of vertical transmission in Zika virus expansion, we evaluated larval pools of perorally infected Aedes aegypti and Ae. albopictus adult female mosquitoes; ≈1/84 larvae tested were Zika virus-positive; and rates varied among mosquito populations. Thus, vertical transmission may play a role in Zika virus spread and maintenance.
Šebesta, Oldřich; Rudolf, Ivo; Betášová, Lenka; Peško, Juraj; Hubálek, Zdeněk
Roč. 17, č. 43 (2012), s. 20301 ISSN 1560-7917 Institutional support: RVO:68081766 Keywords : invasive mosquito species * Aedes albopictus Subject RIV: EG - Zoology Impact factor: 5.491, year: 2012 http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20301
Casas Martínez, Mauricio; Orozco Bonilla, Arnoldo; Muñoz Reyes, Miguel; Ulloa García, Armando; Bond, J Guillermo; Valle Mora, Javier; Weber, Manuel; Rojas, Julio C
In this study, we designed a new tent trap; the BioDiVector (BDV) tent trap, consisting of two rectangular tents that use human bait without endangering the technical personnel. The daily activity pattern of Aedes aegypti and Aedes albopictus in intra, peri, and extradomiciliary sites was studied in an endemic area of dengue in southern Mexico by using the BDV tent trap. Totals of 3,128 individuals of Ae. aegypti and 833 Ae. albopictus were captured. More Ae. aegypti males than females were caught, while the opposite was true with Ae. albopictus. The activity of both mosquito species was affected by the interaction between the collection site and time of day. In general, more individuals of both mosquito species were captured at the extradomicillary sites than at the peri and intradomicillary sites. Mosquitoes showed two peaks of activity, one in the morning and the other in the afternoon, but in general this only occurred at the extradomicillary sites, whereas no peak of activity was observed at the intra and peridomicillary sites. Overall, Ae. aegypti had a higher indirect biting rate than Ae. albopictus. Finally, due to its efficiency, simplicity, and low cost, we suggest the use of this innovative tool for entomological surveillance, bionomics and vector incrimination studies in geographical areas where dengue and other arboviruses are present. © 2013 The Society for Vector Ecology.
Scholte, E.J.; Takken, W.; Knols, B.G.J.
This study describes a laboratory investigation on the use of the insect-pathogenic fungus Metarhizium anisopliae against adult Aedes aegypti and Ae. albopictus mosquitoes. At a dosage of 1.6 × 1010 conidia/m2, applied on material that served as a mosquito resting site, an average of 87.1 ± 2.65% of
Yosefina Dota T
Full Text Available Penelitian yang bertujuan untuk mengetahui eksistensi dan sebaran nyamuk Aedes aegypti dan Aedes albopictus telah dilakukan di Kampus Universitas Hasanuddin, Kec. Tamalanrea, Makassar. Penelitian bersifat eksploratif dengan melakukan sampling terhadap lima lokasi yaitu : a Fak. Peternakan (Utara, b Fak. Hukum (Timur, c Pusat Kegiatan Penelitian/PKP (Selatan, d Workshop/Dekat Pondokan mahasiswa (Barat dan e Fak. MIPA (Tengah. Sampling nyamuk menggunakan metode ovitrap (menggunakan attraktan Eluisine Indica L. dan survei terhadap berbagai tempat penampungan air. Sampel telur dan larva nyamuk yang diperoleh disimpan dalam microtube berisi alkohol 70% kemudian diidentifikasi berdasarkan Rueda (2004. Hasil penelitian menunjukkan bahwa Nyamuk Ae. aegypti dan Ae. albopictus ditemukan hidup dan berkembang biak di kampus Universitas Hasanuddin, Makassar. Eksistensi dan sebaran kedua jenis nyamuk tersebut dipengaruhi oleh faktor adanya manusia/masyarakat kampus yang beraktivitas baik di dalam ruangan (indoor maupun di luar ruangan (outdoor, adanya berbagai tempat penampungan air baik buatan (bak mandi, ember maupun barang bekas (botol/kaleng bekas, tempurung kelapa, vegetasi/tanaman dan berbagai macam hewan yang berada di sekitaran kampus. Hasil penelitian dalam ruangan (indoor menunjukkan bahwa nyamuk Ae. aegypti lebih banyak ditemukan hidup di dalam ruangan gedung PKP sedangkan Ae.albopictus lebih banyak di Fak. Hukum. Hasil penelitian di luar ruangan (outdoor menunjukkan bahwa nyamuk Ae. aegypti lebih banyak ditemukan hidup di area Workshop sedangkan Ae.albopictus lebih banyak di area PKP.
Oswaldo C. Villena
Full Text Available Discarded vehicle tire casings are an important artificial habitat for the developmental stages of numerous vector mosquitoes. Discarded vehicle tires degrade under ultraviolet light and leach numerous soluble metals (e.g., barium, cadmium, zinc and organic substances (e.g., benzothiazole and its derivatives [BZTs], polyaromatic hydrocarbons [PAHs] that could affect mosquito larvae that inhabit the tire casing. This study examined the relationship between soluble zinc, a common marker of tire leachate, on mosquito densities in tire habitats in the field, and tested the effects of tire leachate on the survival and development of newly hatched Aedes albopictus and Aedes triseriatus larvae in a controlled laboratory dose-response experiment. In the field, zinc concentrations were as high as 7.26 mg/L in a single tire and averaged as high as 2.39 (SE ± 1.17 mg/L among tires at a single site. Aedes albopictus (37/42 tires, 81.1% and A. triseriatus (23/42, 54.8% were the most widespread mosquito species, co-occurred in over half (22/42, 52.4% of all tires, and A. triseriatus was only collected without A. albopictus in one tire. Aedes triseriatus was more strongly negatively associated with zinc concentration than A. albopictus, and another common mosquito, C. pipiens, which was found in 17 tires. In the laboratory experiment, A. albopictus per capita rate of population change (λ′ was over 1.0, indicating positive population growth, from 0–8.9 mg/L zinc concentration (0–10,000 mg/L tire leachate, but steeply declined to zero from 44.50–89.00 mg/L zinc (50,000–100,000 mg/L tire leachate. In contrast, A. triseriatus λ′ declined at the lower concentration of 0.05 mg/L zinc (100 mg/L tire leachate, and was zero at 0.45, 8.90, 44.50, and 89.00 mg/L zinc (500, 10,000, 50,000 and 100,000 mg/L tire leachate. These results indicate that tire leachate can have severe negative effects on populations of container-utilizing mosquitoes at
Full Text Available Abstract Background Aedes aegypti (Linnaeus, 1762 and Aedes albopictus (Skuse, 1894 are the main vectors of dengue (DENV and chikungunya (CHIKV viruses worldwide. As there is still no vaccine or specific treatment for DENV and CHIKV, vector control remains the cornerstone of prevention and outbreak control. Unfortunately, vector control programs are facing operational challenges with mosquitoes becoming resistant to commonly used insecticides in several areas through the world. Throughout Central Africa no recent data are available susceptible/resistant status of either vector species since the introduction/arrival of Ae. albopictus in this area. We therefore studied the level of resistance of these two major vectors to insecticides commonly used in Africa for mosquito control. Results Aedes aegypti and Ae. albopictus were sampled in six urban localities of Cameroon (Garoua, Bertoua, Yaoundé, Bafia, Buea and Gabon (Libreville. Larval bioassays, carried out to determine the lethal concentrations (LC50 and LC95 and resistance ratios (RR50 and RR95 suggested that both vector species were susceptible to Bti (Bacillus thuringiensis var israeliensis and temephos. Bioassays were also performed on adults using WHO diagnostic test kits to assess phenotypic resistance to deltamethrin, DDT, fenitrothion and propoxur. These experiments showed that one population of Ae. aegypti (Libreville and two populations of Ae. albopictus (Buea and Yaoundé were resistant to DDT (mortality 36% to 71%. Resistance to deltamethrin was also suspected in Ae. albopictus from Yaoundé (83% mortality. All other field mosquito populations were susceptible to deltamethrin, DDT, fenitrothion and propoxur. No increase in the knockdown times (Kdt50 and Kdt95 was noted in the Yaoundé resistant population compared to other Ae. albopictus populations, suggesting the possible involvement of metabolic resistance to deltamethrin and DDT. Conclusion In view of the recent increase in
Mélissanne de Wispelaere
Full Text Available Japanese encephalitis virus (JEV is the causative agent of Japanese encephalitis, the leading cause of viral encephalitis in Asia. JEV transmission cycle involves mosquitoes and vertebrate hosts. The detection of JEV RNA in a pool of Culex pipiens caught in 2010 in Italy raised the concern of a putative emergence of the virus in Europe. We aimed to study the vector competence of European mosquito populations, such as Cx. pipiens and Aedes albopictus for JEV genotypes 3 and 5.After oral feeding on an infectious blood meal, mosquitoes were dissected at various times post-virus exposure. We found that the peak for JEV infection and transmission was between 11 and 13 days post-virus exposure. We observed a faster dissemination of both JEV genotypes in Ae. albopictus mosquitoes, when compared with Cx. pipiens mosquitoes. We also dissected salivary glands and collected saliva from infected mosquitoes and showed that Ae. albopictus mosquitoes transmitted JEV earlier than Cx. pipiens. The virus collected from Ae. albopictus and Cx. pipiens saliva was competent at causing pathogenesis in a mouse model for JEV infection. Using this model, we found that mosquito saliva or salivary glands did not enhance the severity of the disease.In this study, we demonstrated that European populations of Ae. albopictus and Cx. pipiens were efficient vectors for JEV transmission. Susceptible vertebrate species that develop high viremia are an obligatory part of the JEV transmission cycle. This study highlights the need to investigate the susceptibility of potential JEV reservoir hosts in Europe, notably amongst swine populations and local water birds.
Full Text Available The main constraint to the fight against container-breeding mosquito vectors of human arboviruses is the difficulty in targeting the multiplicity of larval sources, mostly represented by small man-made water containers. The aim of this work is to assess the feasibility of the "auto-dissemination" approach, already tested for Aedes aegypti, as a possible alternative to traditional, inefficient control tools, against Ae. albopictus in urban areas. The approach is based on the possibility that wild adult females, exposed to artificial resting sites contaminated with pyriproxyfen, can disseminate this juvenile hormone analogue to larval habitats, thus interfering with adult emergence.We carried out four field experiments in two areas of Rome that are typically highly infested with Ae. albopictus, i.e. the main cemetery and a small green area within a highly urbanised neighbourhood. In each area we used 10 pyriproxyfen "dissemination" stations, 10 "sentinel" sites and 10 covered, control sites. The sentinel and control sites each contained 25 Ae. albopictus larvae. These were monitored for development and adult emergence.When a 5% pyriproxyfen powder was used to contaminate the dissemination sites, we observed significantly higher mortality at the pupal stage in the sentinel sites (50-70% than in the controls (<2%, showing that pyriproxyfen was transferred by mosquitoes into sentinel sites and that it had a lethal effect.The results support the potential feasibility of the auto-dissemination approach to control Ae. albopictus in urban areas. Further studies will be carried out to optimize the method and provide an effective tool to reduce the biting nuisance caused by this aggressive species and the transmission risk of diseases such as Dengue and Chikungunya. These arboviruses pose an increasing threat in Europe as Ae. albopictus expands its range.
Pei-Sze Jeslyn Wong
Full Text Available Zika virus (ZIKV is a little known arbovirus until it caused a major outbreak in the Pacific Island of Yap in 2007. Although the virus has a wide geographic distribution, most of the known vectors are sylvatic Aedes mosquitoes from Africa where the virus was first isolated. Presently, Ae. aegypti is the only known vector to transmit the virus outside the African continent, though Ae. albopictus has long been a suspected vector. Currently, Ae. albopictus has been shown capable of transmitting more than 20 arboviruses and its notoriety as an important vector came to light during the recent chikungunya pandemic. The vulnerability of Singapore to emerging infectious arboviruses has stimulated our interest to determine the competence of local Ae. albopictus to transmit ZIKV.To determine the competence of Ae. albopictus to ZIKV, we orally infected local mosquito strains to a Ugandan strain virus. Fully engorged mosquitoes were maintained in an environmental chamber set at 29°C and 80-85%RH. Twelve mosquitoes were then sampled daily from day one to seven and on day 10 and 14 post infection (pi. Zika virus titre in the midgut and salivary glands of each mosquito were determined using tissue culture infectious dose50 assay, while transmissibility of the virus was determined by detecting viral antigen in the mosquito saliva by qRT-PCR. High dissemination and transmission rate of ZIKV were observed. By day 7-pi, all mosquitoes have disseminated infection and 73% of these mosquitoes have ZIKV in their saliva. By day 10-pi, all mosquitoes were potentially infectious.The study highlighted the potential of Ae. albopictus to transmit ZIKV and the possibility that the virus could be established locally. Nonetheless, the threat of ZIKV can be mitigated by existing dengue and chikungunya control program being implemented in Singapore.
Saucereau, Yoann; Valiente Moro, Claire; Dieryckx, Cindy; Dupuy, Jean-William; Tran, Florence-Hélène; Girard, Vincent; Potier, Patrick; Mavingui, Patrick
Aedes albopictus is a vector of arboviruses that cause severe diseases in humans such as Chikungunya, Dengue and Zika fevers. The vector competence of Ae. albopictus varies depending on the mosquito population involved and the virus transmitted. Wolbachia infection status in believed to be among key elements that determine viral transmission efficiency. Little is known about the cellular functions mobilized in Ae. albopictus during co-infection by Wolbachia and a given arbovirus. To decipher this tripartite interaction at the molecular level, we performed a proteome analysis in Ae. albopictus C6/36 cells mono-infected by Wolbachia wAlbB strain or Chikungunya virus (CHIKV), and bi-infected. We first confirmed significant inhibition of CHIKV by Wolbachia. Using two-dimensional gel electrophoresis followed by nano liquid chromatography coupled with tandem mass spectrometry, we identified 600 unique differentially expressed proteins mostly related to glycolysis, translation and protein metabolism. Wolbachia infection had greater impact on cellular functions than CHIKV infection, inducing either up or down-regulation of proteins associated with metabolic processes such as glycolysis and ATP metabolism, or structural glycoproteins and capsid proteins in the case of bi-infection with CHIKV. CHIKV infection inhibited expression of proteins linked with the processes of transcription, translation, lipid storage and miRNA pathways. The results of our proteome profiling have provided new insights into the molecular pathways involved in tripartite Ae. albopictus-Wolbachia-CHIKV interaction and may help defining targets for the better implementation of Wolbachia-based strategies for disease transmission control.
Ricardo A Passos
Full Text Available OBJETIVO: Analisar a infestação de Aedes aegypti e Aedes albopictus e verificar sua associação com fatores climáticos e com a sua freqüência em recipientes de área urbana. MÉTODOS: Foi selecionado o município de São Sebastião, localizado no litoral Sudeste do Brasil. Foram utilizados os dados do "Programa de Controle de Vetores de Dengue e Febre Amarela no Estado de São Paulo" que realiza a vigilância entomológica em pontos estratégicos, armadilhas e delimitação de focos. Os pontos estratégicos são imóveis onde existem recipientes em condições favoráveis à proliferação de larvas. Para análise dos dados, foram utilizados os testes de significância estatística: Kruskal-Wallis, Dwass-Steel-Chritchlow-Fligne e Mann-Whitney. RESULTADOS: Verificou-se crescimento anual da positividade de armadilhas e pontos estratégicos para Ae. aegypti e diminuição para Ae. albopictus. Observou-se aumento do número de imaturos de Ae. aegypti e diminuição da outra espécie. Na positividade de imóveis para a presença de larvas, verificou-se aumento gradativo do número de imóveis com Ae. Aegypti, superando a positividade para Ae. albopictus. Houve uma fraca correlação das espécies com os fatores abióticos. As maiores freqüências de imaturos de ambas espécies foram em recipientes artificiais passíveis de remoção. CONCLUSÕES: Os resultados evidenciaram no período de estudo a predominância de Ae. aegypti sobre Ae. albopictus em área urbana, indicando que o crescimento populacional do primeiro parece ter afetado a chance de sua coexistência. Sugere-se que algum processo de seleção natural possa estar operando e desse modo contribuindo para levar à separação das duas espécies.OBJECTIVE: To assess infestation of Aedes aegypti and Aedes albopiticus and describe their association with weather conditions and container colonization in urban areas. METHODS: The town of São Sebastião in the southeastern coast of Brazil
Orta-Pesina, Héctor; Mercado-Hernández, Roberto; Elizondo-Leal, José Fernando
To determine the distribution of Aedes albopictus (Skuse) in Nuevo Leon between 2001 and 2004. Standardized methods were used to collect 6371 samples of mosquito's larvae from 167 sites. The proportions of samples positive for Ae. albopictus were obtained by municipality and year, using the software program Excel. There were 1179 samples positive for Ae. albopictus. This species was distributed over 10 municipalities, as follows: Five on the Gulf of Mexico Coastal Plains, which predominantly have a semi-warm, sub-humid climate, and precipitations almost year round (Allende, Montemorelos, Linares, General Teran, and Santiago); two (Sabinas Hidalgo, and Cadereyta) localized on the North American Great Plains, which have a warm, semiarid climate, and scarce precipitations. The final three were Apodaca, San Nicolas, and Escobedo distributed over the metropolitan area of Monterrey City. Up to January 2004, the second most important epidemiological vector in the transmission cycle of Ae. albopictus worldwide was found in ten municipalities of Nuevo Leon State, Mexico.
Shabani, Farzin; Shafapour Tehrany, Mahyat; Solhjouy-Fard, Samaneh; Kumar, Lalit
Aedes albopictus , the Asian Tiger Mosquito, vector of Chikungunya, Dengue Fever and Zika viruses, has proven its hardy adaptability in expansion from its natural Asian, forest edge, tree hole habitat on the back of international trade transportation, re-establishing in temperate urban surrounds, in a range of water receptacles and semi-enclosures of organic matter. Conventional aerial spray mosquito vector controls focus on wetland and stagnant water expanses, proven to miss the protected hollows and crevices favoured by Ae. albopictus. New control or eradication strategies are thus essential, particular in light of potential expansions in the southeastern and eastern USA. Successful regional vector control strategies require risk level analysis. Should strategies prioritize regions with non-climatic or climatic suitability parameters for Ae. albopictus ? Our study used current Ae. albopictus distribution data to develop two independent models: (i) regions with suitable non-climatic factors, and (ii) regions with suitable climate for Ae. albopictus in southeastern USA. Non-climatic model processing used Evidential Belief Function (EBF), together with six geographical conditioning factors (raster data layers), to establish the probability index. Validation of the analysis results was estimated with area under the curve (AUC) using Ae. albopictus presence data. Climatic modeling was based on two General Circulation Models (GCMs), Miroc3.2 and CSIRO-MK30 running the RCP 8.5 scenario in MaxEnt software. EBF non-climatic model results achieved a 0.70 prediction rate and 0.73 success rate, confirming suitability of the study site regions for Ae. albopictus establishment. The climatic model results showed the best-fit model comprised Coldest Quarter Mean Temp, Precipitation of Wettest Quarter and Driest Quarter Precipitation factors with mean AUC value of 0.86. Both GCMs showed that the whole study site is highly suitable and will remain suitable climatically, according
COMPARISON OF BG-SENTINELH TRAP AND OVIPOSITION CUPS FOR AEDES AEGYPTI AND AEDES ALBOPICTUS SURVEILLANCE IN JACKSONVILLE, FLORIDA, USA JENNIFER A...trap and oviposition cups (OCs) have both proven effective in the surveillance of Aedes species. This study aimed to determine which of the 2 traps could...best characterize the relative population sizes of Aedes albopictus and Aedes aegypti in an urban section of Jacksonville, FL. Until 1986, Ae
Armstrong, Philip M; Andreadis, Theodore G; Shepard, John J; Thomas, Michael C
The Asian tiger mosquito (Aedes albopictus) is an invasive species and important arbovirus vector that was introduced into the U.S. in the 1980's where it continues to expand its range. Winter temperature is an important constraint to its northward expansion, with potential range limits located between the 0° and -5°C mean cold month isotherm. Connecticut is located within this climatic zone and therefore, Ae. albopictus was monitored statewide to assess its northern range expansion and to delineate where populations can stably persist. Ae. albopictus females were monitored at fixed trapping sites throughout Connecticut from June-October over a 20-year period, 1997-2016. In addition, Ae. albopictus larvae and pupae were collected from tire habitats and tires were retrieved from the field in the spring and flooded to evaluate overwintering success of hatching larvae. Ae. albopictus was first detected during statewide surveillance when a single adult female was collected in 2006. This species was not collected again until 2010 and was subsequently detected each successive year with increasing abundance and distribution except following the unusually cold winters of 2014 and 2015. Ae. albopictus mosquitoes were most abundant in urban and suburban locations along the southwestern shoreline of Connecticut; however, single specimens were occasionally detected in central parts of the state. Field-collected females were also screened for arbovirus infection yielding two isolations of Cache Valley virus and one isolation of West Nile virus, highlighting the threat posed by this mosquito. Ae. albopictus overwintered in Connecticut under mild winter conditions as shown by recovery of hatched larvae from field collected tires in spring and by early season detection of larvae and pupae. This study documents the establishment and expansion of Ae. albopictus at the northern boundary of its range in the northeastern U.S. and provides a baseline for monitoring the future spread
Philip M Armstrong
Full Text Available The Asian tiger mosquito (Aedes albopictus is an invasive species and important arbovirus vector that was introduced into the U.S. in the 1980's where it continues to expand its range. Winter temperature is an important constraint to its northward expansion, with potential range limits located between the 0° and -5°C mean cold month isotherm. Connecticut is located within this climatic zone and therefore, Ae. albopictus was monitored statewide to assess its northern range expansion and to delineate where populations can stably persist.Ae. albopictus females were monitored at fixed trapping sites throughout Connecticut from June-October over a 20-year period, 1997-2016. In addition, Ae. albopictus larvae and pupae were collected from tire habitats and tires were retrieved from the field in the spring and flooded to evaluate overwintering success of hatching larvae. Ae. albopictus was first detected during statewide surveillance when a single adult female was collected in 2006. This species was not collected again until 2010 and was subsequently detected each successive year with increasing abundance and distribution except following the unusually cold winters of 2014 and 2015. Ae. albopictus mosquitoes were most abundant in urban and suburban locations along the southwestern shoreline of Connecticut; however, single specimens were occasionally detected in central parts of the state. Field-collected females were also screened for arbovirus infection yielding two isolations of Cache Valley virus and one isolation of West Nile virus, highlighting the threat posed by this mosquito. Ae. albopictus overwintered in Connecticut under mild winter conditions as shown by recovery of hatched larvae from field collected tires in spring and by early season detection of larvae and pupae.This study documents the establishment and expansion of Ae. albopictus at the northern boundary of its range in the northeastern U.S. and provides a baseline for monitoring
Full Text Available Aedes albopictus, the Asian Tiger Mosquito, vector of Chikungunya, Dengue Fever and Zika viruses, has proven its hardy adaptability in expansion from its natural Asian, forest edge, tree hole habitat on the back of international trade transportation, re-establishing in temperate urban surrounds, in a range of water receptacles and semi-enclosures of organic matter. Conventional aerial spray mosquito vector controls focus on wetland and stagnant water expanses, proven to miss the protected hollows and crevices favoured by Ae. albopictus. New control or eradication strategies are thus essential, particular in light of potential expansions in the southeastern and eastern USA. Successful regional vector control strategies require risk level analysis. Should strategies prioritize regions with non-climatic or climatic suitability parameters for Ae. albopictus? Our study used current Ae. albopictus distribution data to develop two independent models: (i regions with suitable non-climatic factors, and (ii regions with suitable climate for Ae. albopictus in southeastern USA. Non-climatic model processing used Evidential Belief Function (EBF, together with six geographical conditioning factors (raster data layers, to establish the probability index. Validation of the analysis results was estimated with area under the curve (AUC using Ae. albopictus presence data. Climatic modeling was based on two General Circulation Models (GCMs, Miroc3.2 and CSIRO-MK30 running the RCP 8.5 scenario in MaxEnt software. EBF non-climatic model results achieved a 0.70 prediction rate and 0.73 success rate, confirming suitability of the study site regions for Ae. albopictus establishment. The climatic model results showed the best-fit model comprised Coldest Quarter Mean Temp, Precipitation of Wettest Quarter and Driest Quarter Precipitation factors with mean AUC value of 0.86. Both GCMs showed that the whole study site is highly suitable and will remain suitable climatically
Maimusa, Hamisu A; Ahmad, Abu Hassan; Kassim, Nur Faeza A; Rahim, Junaid
The life table developmental attributes of laboratory colonies of wild strains of Aedes albopictus and Aedes aegypti were analyzed and compared based on the age-stage, two-sex life table. Findings inclusive in this study are: adult preoviposition periods, total preoviposition period, mean intrinsic rate of increase (r), mean finite rate of increase (λ), net reproductive rates (R0), and mean generation time (T). The total preadult development time was 9.47 days for Ae. albopictus and 8.76 days for Ae. aegypti. The life expectancy was 19.01 days for Ae. albopictus and 19.94 days for Ae. aegypti. Mortality occurred mostly during the adult stage. The mean development time for each stage insignificantly correlated with temperature for Ae. albopictus (r = -0.208, P > 0.05) and (r = -0.312, P > 0.05) for Ae. aegypti. The population parameters suggest that Ae. albopictus and Ae. aegypti populations are r-strategists characterized by a high r, a large R0, and short T. This present study provides the first report to compare the life parameters of Ae. albopictus and Ae. aegypti strains from Penang island, Malaysia.
Knudsen, A B; Romi, R; Majori, G
Aedes albopictus is considered second only to Ae. aegypti in its importance to man as a disease vector of dengue and dengue hemorrhagic fever. The first sighting in 1979 of the vector species in Europe came from Albania; however, it was only when Ae. albopictus was introduced into Italy in 1990, through the importation of used tires, followed by its subsequent spread, that the species was considered as a threat to public health. At the close of 1995, Ae. albopictus infestations have been reported from 10 Italian regions and 19 provinces. The risk for greater distribution of Ae. albopictus in Europe can potentially be projected, based on well-established criteria such as: where the winter monthly mean temperature is 0 degree C, where at least 50 cm of mean annual rainfall occurs, and where the mean summer temperature is approximately 20 degrees C. Those countries where climatic conditions meet such criteria and that may be vulnerable to a potential introduction of Ae. albopictus include Spain, Portugal, Greece, Turkey, France, Albania, and the former Republic of Yugoslavia. The Italian plan of action, established for the surveillance and control of Ae. albopictus, is presented in detail.
Lala Harivelo Raveloson Ravaomanarivo
Conclusions: The seed extracts of these two plants may be used as mosquito controlling agents and offer a new approach to a less costly, practical and environmentally friendly control of vector borne diseases.
Full Text Available The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations.
Guzzetta, Giorgio; Poletti, Piero; Montarsi, Fabrizio; Baldacchino, Frederic; Capelli, Gioia; Rizzoli, Annapaola; Rosà, Roberto; Merler, Stefano
Based on 2015 abundance of Aedes albopictus in nine northern Italian municipalities with temperate continental/oceanic climate, we estimated the basic reproductive number R0 for Zika virus (ZIKV) to be systematically below the epidemic threshold in most scenarios. Results were sensitive to the value of the probability of mosquito infection after biting a viraemic host. Therefore, further studies are required to improve models and predictions, namely evaluating vector competence and potential non-vector transmissions.
Jia, Pengfei; Chen, Xiang; Chen, Jin; Lu, Liang; Liu, Qiyong; Tan, Xiaoyue
Background Global warming has a marked influence on the life cycle of epidemic vectors as well as their interactions with human beings. The Aedes albopictus mosquito as the vector of dengue fever surged exponentia