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Sample records for aegypti mosquito reduction

  1. The immune strategies of mosquito Aedes aegypti against microbial infection.

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    Wang, Yan-Hong; Chang, Meng-Meng; Wang, Xue-Li; Zheng, Ai-Hua; Zou, Zhen

    2018-06-01

    Yellow fever mosquito Aedes aegypti transmits many devastating arthropod-borne viruses (arboviruses), such as dengue virus, yellow fever virus, Chikungunya virus, and Zika virus, which cause great concern to human health. Mosquito control is an effective method to block the spread of infectious diseases. Ae. aegypti uses its innate immune system to fight against arboviruses, parasites, and fungi. In this review, we briefly summarize the recent findings in the immune response of Ae. aegypti against arboviral and entomopathogenic infections. This review enriches our understanding of the mosquito immune system and provides evidence to support the development of novel mosquito control strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Microinjection of A. aegypti Embryos to Obtain Transgenic Mosquitoes

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    Jasinskiene, Nijole; Juhn, Jennifer; James, Anthony A.

    2007-01-01

    In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever. The techniques for correctly preparing microinjection needles, dessicating embryos, and performing microinjection are demonstrated.

  3. Microinjection of A. aegypti embryos to obtain transgenic mosquitoes.

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    Jasinskiene, Nijole; Juhn, Jennifer; James, Anthony A

    2007-01-01

    In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever. The techniques for correctly preparing microinjection needles, desiccating embryos, and performing microinjection are demonstrated.

  4. Fauna de mosquitos asociada con Aedes aegypti en Guaduas, Colombia

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    Víctor Alberto Olano

    1993-06-01

    Full Text Available Durante un estudio sobre la ecología del Aedes aegypti llevado a cabo en el área urbana de Guaduas, Colombia, se hallaron un total de siete especies de mosquitos que compartían hábitats con esta especie. Los criaderos en los cuales se encontró un mayor número de mosquitos asociados con el Aedes aegypti fueron los tanques bajos (albercas. Larvas de Toxorhynchites spp. se encontraron en tanques elevados. Se discute la importancia de estos hallazgos con relación a los aspectos de ecología y control del Aedes aegypti.

  5. Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission

    OpenAIRE

    Roundy, Christopher M.; Azar, Sasha R.; Rossi, Shannan L.; Huang, Jing H.; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J.; Paploski, Igor A.D.; Kitron, Uriel; Ribeiro, Guilherme S.; Hanley, Kathryn A.; Weaver, Scott C.; Vasilakis, Nikos

    2017-01-01

    To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican...

  6. Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission.

    Science.gov (United States)

    Roundy, Christopher M; Azar, Sasha R; Rossi, Shannan L; Huang, Jing H; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J; Paploski, Igor A D; Kitron, Uriel; Ribeiro, Guilherme S; Hanley, Kathryn A; Weaver, Scott C; Vasilakis, Nikos

    2017-04-01

    To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexica strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61% transmission occurred after a murine blood meal (saliva titers up to 4 log 10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, Ae. aegypti mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas.

  7. Larvicidal activity prediction against Aedes aegypti mosquito using computational tools

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    Yudith Cañizares-Carmenate; Mirelys Hernandez-Morfa; Francisco Torrens; Gloria Castellano; Juan A Castillo-Garit

    2017-01-01

    Background & objectives: Aedes aegypti is an important vector for transmission of dengue, yellow fever, chikun- gunya, arthritis, and Zika fever. According to the World Health Organization, it is estimated that Ae. aegypti causes 50 million infections and 25,000 deaths per year. Use of larvicidal agents is one of the recommendations of health organizations to control mosquito populations and limit their distribution. The aim of present study was to deduce a mathematical model to predict the l...

  8. [Detection of Aedes (Stegomyia) Aegypti L. mosquitoes in Sochi city].

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    Riabova, T E; Iunicheva, Iu V; Markovich, N Ia; Ganushkina, L A; Orabeĭ, V G; Sergiev, V P

    2005-01-01

    Few Aedes aegypti females were found when collecting the mosquitoes attacking human beings in the Central District of Sochi in August to September 2001-2004. Ae. aegypti, a vector of dangerous causative agents of diseases, such as yellow and Aden fevers, appeared on the Black Sea coast of the Caucasus is recorded after its long absence. By taking into account the potential epidemic value of Ae. aegypti, it is necessary to make a monitoring in the cities, towns, and settlements to establish the spread, number, and the breading sites of mosquitoes in the given area and to prevent their mass reproduction. The effectiveness of Ae. albopictus as a vector of Aden fever has been established in different regions of the world. Entomological surveys for Ae. albopictus should be made in the areas of Russia where Ae. aegypti mosquitoes were distributed early in the past century, particularly in the southern port towns and settlements of Russia. Ae. albopictus is potentially able to spread to the north further than is Ae. aegypti.

  9. Mosquito attractant blends to trap host seeking Aedes aegypti.

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    Mathew, Nisha; Ayyanar, Elango; Shanmugavelu, Sabesan; Muthuswamy, Kalyanasundaram

    2013-03-01

    Aedes aegypti is the key vector of three important arboviral diseases -dengue, yellow fever and chikungunya. To identify volatile chemicals which could be used in odour based traps for Aedes mosquito surveillance, a few synthetic compounds and compound blends have been evaluated in an indigenously designed olfactometer. A total of 24 compounds and seven compound blends were screened against unfed adult female Ae. aegypti mosquitoes for attraction and compared with control group. The attractancy or repellency index of the test material to mosquitoes was calculated and rated them as class-1, class-2 and class-3 with rating values ranging 1-15, 16-33 and 34-100 respectively. Out of the 24 compounds tested, six were showing significant attractancy (P attractancy with a rating value of 57.81. Sixteen compounds showed significant repellency (P attractancy (P attractancy.

  10. Formulas of components of citronella oil against mosquitoes (Aedes aegypti).

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    Hsu, Wey-Shin; Yen, Jui-Hung; Wang, Yei-Shung

    2013-01-01

    The mosquito Aedes aegypti is an epidemic vector of several diseases such as dengue fever and yellow fever. Several pesticides are used to control the mosquito population. Because of their frequent use, some mosquitoes have developed resistance. In this study, we used the Y-tube olfactometer to test essential oils of Cymbopogon species and screened specific formulas of components as repellents against Ae. aegypti. At 400 μL, the extracted oil of citronella grass (Cymbopogon nardus) and myrcene produced a low-active response by inhibiting mosquito host-seeking activity. Citronella grass, lemon grass (Cymbopogon citratus), citral and myrcene also produced a low-treatment response to repellents, for more potential to affect host-seeking behavior. Furthermore, the mixture of citral, myrcene, and citronellal oil (C:M:Ci = 6:4:1) greatly affected and inhibited host-seeking behavior (76% active response; 26% treatment response with 40 μL; 42.5%, 18% with 400 μL; and 19%, 23% with 1000 μL). As compared with the result for N,N-diethyl-3-methylbenzamide (DEET; 44%, 22% with 400 μL), adjusting the composition formulas of citronella oil had a synergistic effect, for more effective repellent against Ae. aegypti.

  11. Population genomics reveals that an anthropophilic population of Aedes aegypti mosquitoes in West Africa recently gave rise to American and Asian populations of this major disease vector.

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    Crawford, Jacob E; Alves, Joel M; Palmer, William J; Day, Jonathan P; Sylla, Massamba; Ramasamy, Ranjan; Surendran, Sinnathamby N; Black, William C; Pain, Arnab; Jiggins, Francis M

    2017-02-28

    The mosquito Aedes aegypti is the main vector of dengue, Zika, chikungunya and yellow fever viruses. This major disease vector is thought to have arisen when the African subspecies Ae. aegypti formosus evolved from being zoophilic and living in forest habitats into a form that specialises on humans and resides near human population centres. The resulting domestic subspecies, Ae. aegypti aegypti, is found throughout the tropics and largely blood-feeds on humans. To understand this transition, we have sequenced the exomes of mosquitoes collected from five populations from around the world. We found that Ae. aegypti specimens from an urban population in Senegal in West Africa were more closely related to populations in Mexico and Sri Lanka than they were to a nearby forest population. We estimate that the populations in Senegal and Mexico split just a few hundred years ago, and we found no evidence of Ae. aegypti aegypti mosquitoes migrating back to Africa from elsewhere in the tropics. The out-of-Africa migration was accompanied by a dramatic reduction in effective population size, resulting in a loss of genetic diversity and rare genetic variants. We conclude that a domestic population of Ae. aegypti in Senegal and domestic populations on other continents are more closely related to each other than to other African populations. This suggests that an ancestral population of Ae. aegypti evolved to become a human specialist in Africa, giving rise to the subspecies Ae. aegypti aegypti. The descendants of this population are still found in West Africa today, and the rest of the world was colonised when mosquitoes from this population migrated out of Africa. This is the first report of an African population of Ae. aegypti aegypti mosquitoes that is closely related to Asian and American populations. As the two subspecies differ in their ability to vector disease, their existence side by side in West Africa may have important implications for disease transmission.

  12. Population genomics reveals that an anthropophilic population of Aedes aegypti mosquitoes in West Africa recently gave rise to American and Asian populations of this major disease vector

    KAUST Repository

    Crawford, Jacob E.

    2017-02-20

    BackgroundThe mosquito Aedes aegypti is the main vector of dengue, Zika, chikungunya and yellow fever viruses. This major disease vector is thought to have arisen when the African subspecies Ae. aegypti formosus evolved from being zoophilic and living in forest habitats into a form that specialises on humans and resides near human population centres. The resulting domestic subspecies, Ae. aegypti aegypti, is found throughout the tropics and largely blood-feeds on humans.ResultsTo understand this transition, we have sequenced the exomes of mosquitoes collected from five populations from around the world. We found that Ae. aegypti specimens from an urban population in Senegal in West Africa were more closely related to populations in Mexico and Sri Lanka than they were to a nearby forest population. We estimate that the populations in Senegal and Mexico split just a few hundred years ago, and we found no evidence of Ae. aegypti aegypti mosquitoes migrating back to Africa from elsewhere in the tropics. The out-of-Africa migration was accompanied by a dramatic reduction in effective population size, resulting in a loss of genetic diversity and rare genetic variants.ConclusionsWe conclude that a domestic population of Ae. aegypti in Senegal and domestic populations on other continents are more closely related to each other than to other African populations. This suggests that an ancestral population of Ae. aegypti evolved to become a human specialist in Africa, giving rise to the subspecies Ae. aegypti aegypti. The descendants of this population are still found in West Africa today, and the rest of the world was colonised when mosquitoes from this population migrated out of Africa. This is the first report of an African population of Ae. aegypti aegypti mosquitoes that is closely related to Asian and American populations. As the two subspecies differ in their ability to vector disease, their existence side by side in West Africa may have important implications for

  13. Vertical Transmission of Zika Virus in Aedes aegypti Mosquitoes.

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    Thangamani, Saravanan; Huang, Jing; Hart, Charles E; Guzman, Hilda; Tesh, Robert B

    2016-11-02

    Previous experimental studies have demonstrated that a number of mosquito-borne flavivirus pathogens are vertically transmitted in their insect vectors, providing a mechanism for these arboviruses to persist during adverse climatic conditions or in the absence of a susceptible vertebrate host. In this study, designed to test whether Zika virus (ZIKV) could be vertically transmitted, female Aedes aegypti and Aedes albopictus were injected with ZIKV, and their F 1 adult progeny were tested for ZIKV infection. Six of 69 Ae. aegypti pools, comprised of a total of 1,738 F 1 adults, yielded ZIKV upon culture, giving a minimum filial infection rate of 1:290. In contrast, none of 803 F 1 Ae. albopictus adults (32 pools) yielded ZIKV. The MFIR for Ae. aegypti was comparable to MFIRs reported for other flaviviruses in mosquitoes, including dengue, Japanese encephalitis, yellow fever, West Nile, and St. Louis encephalitis viruses. The results suggest that vertical transmission may provide a potential mechanism for the virus to survive during adverse conditions. © The American Society of Tropical Medicine and Hygiene.

  14. Transcriptome analysis of Aedes aegypti transgenic mosquitoes with altered immunity.

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    Zou, Zhen; Souza-Neto, Jayme; Xi, Zhiyong; Kokoza, Vladimir; Shin, Sang Woon; Dimopoulos, George; Raikhel, Alexander

    2011-11-01

    The mosquito immune system is involved in pathogen-elicited defense responses. The NF-κB factors REL1 and REL2 are downstream transcription activators of Toll and IMD immune pathways, respectively. We have used genome-wide microarray analyses to characterize fat-body-specific gene transcript repertoires activated by either REL1 or REL2 in two transgenic strains of the mosquito Aedes aegypti. Vitellogenin gene promoter was used in each transgenic strain to ectopically express either REL1 (REL1+) or REL2 (REL2+) in a sex, tissue, and stage specific manner. There was a significant change in the transcript abundance of 297 (79 up- and 218 down-regulated) and 299 (123 up- and 176 down-regulated) genes in fat bodies of REL1+ and REL2+, respectively. Over half of the induced genes had predicted functions in immunity, and a large group of these was co-regulated by REL1 and REL2. By generating a hybrid transgenic strain, which ectopically expresses both REL1 and REL2, we have shown a synergistic action of these NF-κB factors in activating immune genes. The REL1+ immune transcriptome showed a significant overlap with that of cactus (RNAi)-depleted mosquitoes (50%). In contrast, the REL2+ -regulated transcriptome differed from the relatively small group of gene transcripts regulated by RNAi depletion of a putative inhibitor of the IMD pathway, caspar (35 up- and 140 down-regulated), suggesting that caspar contributes to regulation of a subset of IMD-pathway controlled genes. Infections of the wild type Ae. aegypti with Plasmodium gallinaceum elicited the transcription of a distinct subset of immune genes (76 up- and 25 down-regulated) relative to that observed in REL1+ and REL2+ mosquitoes. Considerable overlap was observed between the fat body transcriptome of Plasmodium-infected mosquitoes and that of mosquitoes with transiently depleted PIAS, an inhibitor of the JAK-STAT pathway. PIAS gene silencing reduced Plasmodium proliferation in Ae. aegypti, indicating the

  15. Transcriptome analysis of Aedes aegypti transgenic mosquitoes with altered immunity.

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    Zhen Zou

    2011-11-01

    Full Text Available The mosquito immune system is involved in pathogen-elicited defense responses. The NF-κB factors REL1 and REL2 are downstream transcription activators of Toll and IMD immune pathways, respectively. We have used genome-wide microarray analyses to characterize fat-body-specific gene transcript repertoires activated by either REL1 or REL2 in two transgenic strains of the mosquito Aedes aegypti. Vitellogenin gene promoter was used in each transgenic strain to ectopically express either REL1 (REL1+ or REL2 (REL2+ in a sex, tissue, and stage specific manner. There was a significant change in the transcript abundance of 297 (79 up- and 218 down-regulated and 299 (123 up- and 176 down-regulated genes in fat bodies of REL1+ and REL2+, respectively. Over half of the induced genes had predicted functions in immunity, and a large group of these was co-regulated by REL1 and REL2. By generating a hybrid transgenic strain, which ectopically expresses both REL1 and REL2, we have shown a synergistic action of these NF-κB factors in activating immune genes. The REL1+ immune transcriptome showed a significant overlap with that of cactus (RNAi-depleted mosquitoes (50%. In contrast, the REL2+ -regulated transcriptome differed from the relatively small group of gene transcripts regulated by RNAi depletion of a putative inhibitor of the IMD pathway, caspar (35 up- and 140 down-regulated, suggesting that caspar contributes to regulation of a subset of IMD-pathway controlled genes. Infections of the wild type Ae. aegypti with Plasmodium gallinaceum elicited the transcription of a distinct subset of immune genes (76 up- and 25 down-regulated relative to that observed in REL1+ and REL2+ mosquitoes. Considerable overlap was observed between the fat body transcriptome of Plasmodium-infected mosquitoes and that of mosquitoes with transiently depleted PIAS, an inhibitor of the JAK-STAT pathway. PIAS gene silencing reduced Plasmodium proliferation in Ae. aegypti, indicating

  16. Competence of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus Mosquitoes as Zika Virus Vectors, China.

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    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

    2017-07-01

    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.

  17. Competence of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus Mosquitoes as Zika Virus Vectors, China

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    Liu, Zhuanzhuan; Zhou, Tengfei; Lai, Zetian; Zhang, Zhenhong; Jia, Zhirong; Zhou, Guofa; Williams, Tricia; Xu, Jiabao; Gu, Jinbao; Zhou, Xiaohong; Lin, Lifeng; Yan, Guiyun

    2017-01-01

    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

  18. The bacterium Wolbachia exploits host innate immunity to establish a symbiotic relationship with the dengue vector mosquito Aedes aegypti.

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    Pan, Xiaoling; Pike, Andrew; Joshi, Deepak; Bian, Guowu; McFadden, Michael J; Lu, Peng; Liang, Xiao; Zhang, Fengrui; Raikhel, Alexander S; Xi, Zhiyong

    2018-01-01

    A host's immune system plays a central role in shaping the composition of the microbiota and, in return, resident microbes influence immune responses. Symbiotic associations of the maternally transmitted bacterium Wolbachia occur with a wide range of arthropods. It is, however, absent from the dengue and Zika vector mosquito Aedes aegypti in nature. When Wolbachia is artificially forced to form symbiosis with this new mosquito host, it boosts the basal immune response and enhances the mosquito's resistance to pathogens, including dengue, Zika virus and malaria parasites. The mechanisms involved in establishing a symbiotic relationship between Wolbachia and A. aegypti, and the long-term outcomes of this interaction, are not well understood. Here, we have demonstrated that both the immune deficiency (IMD) and Toll pathways are activated by the Wolbachia strain wAlbB upon its introduction into A. aegypti. Silencing the Toll and IMD pathways via RNA interference reduces the wAlbB load. Notably, wAlbB induces peptidoglycan recognition protein (PGRP)-LE expression in the carcass of A. aegypti, and its silencing results in a reduction of symbiont load. Using transgenic mosquitoes with stage-specific induction of the IMD and Toll pathways, we have shown that elevated wAlbB infection in these mosquitoes is maintained via maternal transmission. These results indicate that host innate immunity is utilized to establish and promote host-microbial symbiosis. Our results will facilitate a long-term projection of the stability of the Wolbachia-A. aegypti mosquito system that is being developed to control dengue and Zika virus transmission to humans.

  19. Field validation of a transcriptional assay for the prediction of age of uncaged Aedes aegypti mosquitoes in Northern Australia.

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    Leon E Hugo

    Full Text Available BACKGROUND: New strategies to eliminate dengue have been proposed that specifically target older Aedes aegypti mosquitoes, the proportion of the vector population that is potentially capable of transmitting dengue viruses. Evaluation of these strategies will require accurate and high-throughput methods of predicting mosquito age. We previously developed an age prediction assay for individual Ae. aegypti females based on the transcriptional profiles of a selection of age responsive genes. Here we conducted field testing of the method on Ae. aegypti that were entirely uncaged and free to engage in natural behavior. METHODOLOGY/PRINCIPAL FINDINGS: We produced "free-range" test specimens by releasing 8007 adult Ae. aegypti inside and around an isolated homestead in north Queensland, Australia, and recapturing females at two day intervals. We applied a TaqMan probe-based assay design that enabled high-throughput quantitative RT-PCR of four transcripts from three age-responsive genes and a reference gene. An age prediction model was calibrated on mosquitoes maintained in small sentinel cages, in which 68.8% of the variance in gene transcription measures was explained by age. The model was then used to predict the ages of the free-range females. The relationship between the predicted and actual ages achieved an R(2 value of 0.62 for predictions of females up to 29 days old. Transcriptional profiles and age predictions were not affected by physiological variation associated with the blood feeding/egg development cycle and we show that the age grading method could be applied to differentiate between two populations of mosquitoes having a two-fold difference in mean life expectancy. CONCLUSIONS/SIGNIFICANCE: The transcriptional profiles of age responsive genes facilitated age estimates of near-wild Ae. aegypti females. Our age prediction assay for Ae. aegypti provides a useful tool for the evaluation of mosquito control interventions against dengue where

  20. Using Adult Mosquitoes to Transfer Insecticides to Aedes Aegypti Larval Habitats

    Science.gov (United States)

    2009-07-14

    13:56–67. 14. Dye C (1984) Models for the population dynamics of the yellow - fever mosquito, Aedes aegypti. J Anim Ecol 53:247–268. 15. Macdonald G...dengue hemorrhagic fever and 22,000 deaths (ref. 1 and www.who.int/mediacentre/factsheets/fs117/en/ print.html). Aedes aegypti (Linnaeus) transmits the...insect growth regulator pyriproxyfen to larval microcosms by gravid Aedes albopictus and Ochlerotatus trise- riatus mosquitoes in the laboratory. Med

  1. Effects of Preexposure to DEET on the Downstream Blood-Feeding Behaviors of Aedes aegypti (Diptera: Culicidae) Mosquitoes.

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    Sugiharto, Victor A; Grieco, John P; Murphy, Jittawadee R; Olsen, Cara H; Colacicco-Mayhugh, Michelle G; Stewart, V Ann; Achee, Nicole L; Turell, Michael J

    2016-06-10

    Mosquito behavior is heavily influenced by the chemical molecules in the environment. This knowledge can be used to modify insect behaviors; particularly to reduce vector-host contact as a powerful method for disease prevention. N,N-Diethyl-meta-toluamide (DEET) is the most widely used insect repellent in the market and an excellent example of a chemical that has been used to modify insect behavior for disease prevention. However, genetic insensitivity and habituation in Aedes aegypti (L.) mosquitoes after preexposure to DEET have been reported. In this study, we investigated the effect of preexposure to DEET on the downstream blood-feeding behavior of Ae. aegypti mosquitoes and the duration of the effect. We exposed mosquitoes to four different DEET concentrations: 0.10, 0.12, 0.14, and 0.16% for 10 min then allowed the mosquitoes to blood-feed on an artificial blood-feeding system either immediately or after being held for 1, 3, 6, or 24 h following DEET exposure. We found that preexposing Ae. aegypti mosquitoes to 0.14 or 0.16% DEET lowered their blood engorgement level, but did not alter their landing and probing behavior when compared to the control test populations. The reduction in complete blood-feeding was observed at all time periods tested, but was only statistically significant at 3 and 6 h after the preexposure process. Because reduction in blood meal has been associated with increased refeeding, future studies analyzing the effect of this behavior using arbovirus-infected mosquitoes are needed to address the concern of potentially increased vectorial capacity. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Infection of adult Aedes aegypti and Ae. albopictus mosquitoes with the entomopathogenic fungus Metarhizium anisopliae

    NARCIS (Netherlands)

    Scholte, E.J.; Takken, W.; Knols, B.G.J.

    2007-01-01

    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

  3. Identification of insecticidal principals from cucumber seed oil against the yellow fever mosquito, Aedes aegypti

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    The yellow fever mosquito, Aedes aegypti, is one of the most medically important mosquito species due to its ability to spread viruses of yellow fever, dengue fever and Zika in humans. In this study, the insecticidal activity of seventeen plant essential oils were evaluated to toxicity by topical a...

  4. Impact of Wolbachia on infection with chikungunya and yellow fever viruses in the mosquito vector Aedes aegypti.

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    Andrew F van den Hurk

    Full Text Available Incidence of disease due to dengue (DENV, chikungunya (CHIKV and yellow fever (YFV viruses is increasing in many parts of the world. The viruses are primarily transmitted by Aedes aegypti, a highly domesticated mosquito species that is notoriously difficult to control. When transinfected into Ae. aegypti, the intracellular bacterium Wolbachia has recently been shown to inhibit replication of DENVs, CHIKV, malaria parasites and filarial nematodes, providing a potentially powerful biocontrol strategy for human pathogens. Because the extent of pathogen reduction can be influenced by the strain of bacterium, we examined whether the wMel strain of Wolbachia influenced CHIKV and YFV infection in Ae. aegypti. Following exposure to viremic blood meals, CHIKV infection and dissemination rates were significantly reduced in mosquitoes with the wMel strain of Wolbachia compared to Wolbachia-uninfected controls. However, similar rates of infection and dissemination were observed in wMel infected and non-infected Ae. aegypti when intrathoracic inoculation was used to deliver virus. YFV infection, dissemination and replication were similar in wMel-infected and control mosquitoes following intrathoracic inoculations. In contrast, mosquitoes with the wMelPop strain of Wolbachia showed at least a 10(4 times reduction in YFV RNA copies compared to controls. The extent of reduction in virus infection depended on Wolbachia strain, titer and strain of the virus, and mode of exposure. Although originally proposed for dengue biocontrol, our results indicate a Wolbachia-based strategy also holds considerable promise for YFV and CHIKV suppression.

  5. Repellent Activity of Catnip Extract (Nepeta cataria L,) Against Aedes aegypti Mosquito as Dengue Vector

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    Doraysamy, Doraysamy; Mulyaningsih, Budi; Ernaningsih, Ernaningsih

    2016-01-01

    ABSTRACTIntroduction: Dengue infection has been a major concern for decades. Prevention from getting bitten by Aedes aegypti mosquito is considered better than cure as there is no specific antiviral treatment for dengue. Recently, catnip (Nepeta cataria L.) extract has been formulated and marketed as an alternative for protection against mosquitoes and act as a natural form of mosquito repellent.Objectives: To understand the repelling properties of both DEET and N. cataria L. extract and to c...

  6. Superinfection interference between dengue-2 and dengue-4 viruses in Aedes aegypti mosquitoes.

    Science.gov (United States)

    Muturi, Ephantus J; Buckner, Eva; Bara, Jeffrey

    2017-04-01

    Dengue virus consists of four antigenically distinct serotypes (DENV 1-4) that are transmitted to humans by Aedes aegypti and Aedes albopictus mosquitoes. In many dengue-endemic regions, co-circulation of two or more DENV serotypes is fairly common increasing the likelihood for exposure of the two vectors to multiple serotypes. We used a model system of DENV-2 and DENV-4 to investigate how prior exposure of Aedes aegypti to one DENV serotype affects its susceptibility to another serotype. Aedes aegypti mosquitoes were sequentially infected with DENV-2 and DENV-4 and the infection and dissemination rates for each virus determined. We found that prior infection of Ae. aegypti mosquitoes with DENV-4 rendered them significantly less susceptible to secondary infection with DENV-2. Although the results were not statistically significant, mosquitoes infected with DENV-2 were also less susceptible to secondary infection with DENV-4. The midgut dissemination and population dissemination rates for DENV-2 were significantly higher than those of DENV-4 when either virus was administered 7 days after administration of either a non-infectious blood meal or a blood meal containing a heterologous dengue serotype. These results demonstrate that superinfection interference between DENV serotypes is possible within Ae. aegypti mosquitoes, but its effect on DENV epidemiology may be dependent on the fitness of interacting serotypes. © 2017 John Wiley & Sons Ltd.

  7. Horizontal gene transfer between Wolbachia and the mosquito Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Walker Thomas

    2009-01-01

    Full Text Available Abstract Background The evolutionary importance of horizontal gene transfer (HGT from Wolbachia endosymbiotic bacteria to their eukaryotic hosts is a topic of considerable interest and debate. Recent transfers of genome fragments from Wolbachia into insect chromosomes have been reported, but it has been argued that these fragments may be on an evolutionary trajectory to degradation and loss. Results We have discovered a case of HGT, involving two adjacent genes, between the genomes of Wolbachia and the currently Wolbachia-uninfected mosquito Aedes aegypti, an important human disease vector. The lower level of sequence identity between Wolbachia and insect, the transcription of all the genes involved, and the fact that we have identified homologs of the two genes in another Aedes species (Ae. mascarensis, suggest that these genes are being expressed after an extended evolutionary period since horizontal transfer, and therefore that the transfer has functional significance. The association of these genes with Wolbachia prophage regions also provides a mechanism for the transfer. Conclusion The data support the argument that HGT between Wolbachia endosymbiotic bacteria and their hosts has produced evolutionary innovation.

  8. Behavioral Response of Aedes aegypti Mosquito towards Essential Oils Using Olfactometer

    Science.gov (United States)

    Uniyal, Ashish; Tikar, Sachin N; Mendki, Murlidhar J; Singh, Ram; Shukla, Shakti V; Agrawal, Om P; Veer, Vijay; Sukumaran, Devanathan

    2016-01-01

    Background: Aedes aegypti mosquito is responsible for transmitting human diseases like dengue and chikungunya. Personal or space protection with insect repellents is a practical approach to reducing human mosquito contact, thereby minimizing disease transmission. Essential oils are natural volatile substances from plants used as protective measure against blood-sucking mosquitoes. Methods: Twenty-three essential oils were evaluated for their repellent effect against Ae. aegypti female mosquito in laboratory conditions using Y-tube olfactometer. Results: The essential oils exhibited varying degree of repellency. Litsea oil showed 50.31%, 60.2 %, and 77.26% effective mean repellency at 1 ppm, 10 ppm and 100 ppm respectively, while DEET exhibited 59.63%, 68.63%, 85.48% and DEPA showed 57.97%, 65.43%, and 80.62% repellency at respective above concentrations. Statistical analysis revealed that among the tested essential oils, litsea oil had effective repellency in comparison with DEET and DEPA against Ae. aegypti mosquito at all concentration. Essential oils, DEET and DEPA showed significant repellence against Ae. aegypti (Poil exhibited effective percentage repellency similar to DEET and DEPA. The essential oils are natural plant products that may be useful for developing safer and newer herbal based effective mosquito repellents. PMID:27308295

  9. Behavioral Response of Aedes aegypti Mosquito towards Essential Oils Using Olfactometer

    Directory of Open Access Journals (Sweden)

    Ashish Uniyal

    2016-01-01

    Full Text Available Background: Aedes aegypti mosquito is responsible for transmitting human diseases like dengue and chikungunya. Personal or space protection with insect repellents is a practical approach to reducing human mosquito contact, thereby minimizing disease transmission. Essential oils are natural volatile substances from plants used as protective measure against blood-sucking mosquitoes.Methods: Twenty-three essential oils were evaluated for their repellent effect against Ae. aegypti female mosquito in laboratory conditions using Y-tube olfactometer.  Results: The essential oils exhibited varying degree of repellency. Litsea oil showed 50.31%, 60.2 %, and 77.26% effective mean repellency at 1 ppm, 10 ppm and 100 ppm respectively, while DEET exhibited 59.63%, 68.63%, 85.48% and DEPA showed 57.97%, 65.43%, and 80.62% repellency at respective above concentrations. Statistical analysis revealed that among the tested essential oils, litsea oil had effective repellency in comparison with DEET and DEPA against Ae. aegypti mosquito at all concentration. Essential oils, DEET and DEPA showed significant repellence against Ae. aegypti (P< 0.05 at all 3 concentration tested.Conclusion: Litsea oil exhibited effective percentage repellency similar to DEET and DEPA. The essential oils are natural plant products that may be useful for developing safer and newer herbal based effective mosquito repellents.

  10. Behavioral Response of Aedes aegypti Mosquito towards Essential Oils Using Olfactometer.

    Science.gov (United States)

    Uniyal, Ashish; Tikar, Sachin N; Mendki, Murlidhar J; Singh, Ram; Shukla, Shakti V; Agrawal, Om P; Veer, Vijay; Sukumaran, Devanathan

    2016-09-01

    Aedes aegypti mosquito is responsible for transmitting human diseases like dengue and chikungunya. Personal or space protection with insect repellents is a practical approach to reducing human mosquito contact, thereby minimizing disease transmission. Essential oils are natural volatile substances from plants used as protective measure against blood-sucking mosquitoes. Twenty-three essential oils were evaluated for their repellent effect against Ae. aegypti female mosquito in laboratory conditions using Y-tube olfactometer. The essential oils exhibited varying degree of repellency. Litsea oil showed 50.31%, 60.2 %, and 77.26% effective mean repellency at 1 ppm, 10 ppm and 100 ppm respectively, while DEET exhibited 59.63%, 68.63%, 85.48% and DEPA showed 57.97%, 65.43%, and 80.62% repellency at respective above concentrations. Statistical analysis revealed that among the tested essential oils, litsea oil had effective repellency in comparison with DEET and DEPA against Ae. aegypti mosquito at all concentration. Essential oils, DEET and DEPA showed significant repellence against Ae. aegypti (Prepellency similar to DEET and DEPA. The essential oils are natural plant products that may be useful for developing safer and newer herbal based effective mosquito repellents.

  11. Use of Nicotiana tabacum L extract for anti-Aedes Aegypti mosquito paint

    Science.gov (United States)

    Sandralintang, Trisiana Chrysanthi; Fauzantoro, Ahmad; Hermansyah, Heri; Jufri, Mahdi; Gozan, Misri

    2018-02-01

    This study intended to formulate mosquito repellent paints based tobacco leaf extracts-free pyrethroid substance which is safe for users. The active substance which was added to the paint as a mosquito repellent was an extract of tobacco leaves. The result of Anti-mosquito paint formulation produced was according to the Indonesia National Standard (SNI). The results of anti-Aedes Aegypti mosquito paint effectiveness test showed that 5% concentration of tobacco extract could kill half of the mosquito population (LC50) for 2 hours, the concentration of tobacco extract between 3-5% killed half the mosquito population (LC50) during 4 hours, while 1-3% and 0-1% concentration of tobacco extract killed half the mosquito population (LC50) for 6 and 24 hours, respectively.

  12. Characteristics of Aedes aegypti adult mosquitoes in rural and urban areas of western and coastal Kenya.

    Directory of Open Access Journals (Sweden)

    Bryson Alberto Ndenga

    Full Text Available Aedes aegypti is the main vector for yellow fever, dengue, chikungunya and Zika viruses. Recent outbreaks of dengue and chikungunya have been reported in Kenya. Presence and abundance of this vector is associated with the risk for the occurrence and transmission of these diseases. This study aimed to characterize the presence and abundance of Ae. aegypti adult mosquitoes from rural and urban sites in western and coastal regions of Kenya. Presence and abundance of Ae. aegypti adult mosquitoes were determined indoors and outdoors in two western (urban Kisumu and rural Chulaimbo and two coastal (urban Ukunda and rural Msambweni sites in Kenya. Sampling was performed using quarterly human landing catches, monthly Prokopack automated aspirators and monthly Biogents-sentinel traps. A total of 2,229 adult Ae. aegypti mosquitoes were collected: 785 (35.2% by human landing catches, 459 (20.6% by Prokopack aspiration and 985 (44.2% by Biogents-sentinel traps. About three times as many Ae. aegypti mosquitoes were collected in urban than rural sites (1,650 versus 579. Comparable numbers were collected in western (1,196 and coastal (1,033 sites. Over 80% were collected outdoors through human landing catches and Prokopack aspiration. The probability of collecting Ae. aegypti mosquitoes by human landing catches was significantly higher in the afternoon than morning hours (P<0.001, outdoors than indoors (P<0.001 and in urban than rural sites (P = 0.008. Significantly more Ae. aegypti mosquitoes were collected using Prokopack aspiration outdoors than indoors (P<0.001 and in urban than rural areas (P<0.001. Significantly more mosquitoes were collected using Biogents-sentinel traps in urban than rural areas (P = 0.008 and in western than coastal sites (P = 0.006. The probability of exposure to Ae. aegypti bites was highest in urban areas, outdoors and in the afternoon hours. These characteristics have major implications for the possible transmission of arboviral

  13. Characteristics of Aedes aegypti adult mosquitoes in rural and urban areas of western and coastal Kenya.

    Science.gov (United States)

    Ndenga, Bryson Alberto; Mutuku, Francis Maluki; Ngugi, Harun Njenga; Mbakaya, Joel Omari; Aswani, Peter; Musunzaji, Peter Siema; Vulule, John; Mukoko, Dunstan; Kitron, Uriel; LaBeaud, Angelle Desiree

    2017-01-01

    Aedes aegypti is the main vector for yellow fever, dengue, chikungunya and Zika viruses. Recent outbreaks of dengue and chikungunya have been reported in Kenya. Presence and abundance of this vector is associated with the risk for the occurrence and transmission of these diseases. This study aimed to characterize the presence and abundance of Ae. aegypti adult mosquitoes from rural and urban sites in western and coastal regions of Kenya. Presence and abundance of Ae. aegypti adult mosquitoes were determined indoors and outdoors in two western (urban Kisumu and rural Chulaimbo) and two coastal (urban Ukunda and rural Msambweni) sites in Kenya. Sampling was performed using quarterly human landing catches, monthly Prokopack automated aspirators and monthly Biogents-sentinel traps. A total of 2,229 adult Ae. aegypti mosquitoes were collected: 785 (35.2%) by human landing catches, 459 (20.6%) by Prokopack aspiration and 985 (44.2%) by Biogents-sentinel traps. About three times as many Ae. aegypti mosquitoes were collected in urban than rural sites (1,650 versus 579). Comparable numbers were collected in western (1,196) and coastal (1,033) sites. Over 80% were collected outdoors through human landing catches and Prokopack aspiration. The probability of collecting Ae. aegypti mosquitoes by human landing catches was significantly higher in the afternoon than morning hours (P<0.001), outdoors than indoors (P<0.001) and in urban than rural sites (P = 0.008). Significantly more Ae. aegypti mosquitoes were collected using Prokopack aspiration outdoors than indoors (P<0.001) and in urban than rural areas (P<0.001). Significantly more mosquitoes were collected using Biogents-sentinel traps in urban than rural areas (P = 0.008) and in western than coastal sites (P = 0.006). The probability of exposure to Ae. aegypti bites was highest in urban areas, outdoors and in the afternoon hours. These characteristics have major implications for the possible transmission of arboviral

  14. Olfactory learning and memory in the disease vector mosquito Aedes aegypti

    OpenAIRE

    Vinauger, Clément; Lutz, Eleanor K.; Riffell, Jeffrey A.

    2014-01-01

    Olfactory learning in blood-feeding insects, such as mosquitoes, could play an important role in host preference and disease transmission. However, standardised protocols allowing testing of their learning abilities are currently lacking, and how different olfactory stimuli are learned by these insects remains unknown. Using a Pavlovian conditioning paradigm, we trained individuals and groups of Aedes aegypti mosquitoes to associate an odorant conditioned stimulus (CS) with a blood-reinforced...

  15. Wolbachia infection does not alter attraction of the mosquito Aedes (Stegomyia) aegypti to human odours

    NARCIS (Netherlands)

    Turley, A.P.; Smallegange, R.C.; Takken, W.; Zalucki, M.P.; O'Neill, S.L.; McGraw, E.A.

    2014-01-01

    The insect endosymbiont Wolbachia pipientis (Rickettsiales: Rickettsiaceae) is undergoing field trials around the world to determine if it can reduce transmission of dengue virus from the mosquito Stegomyia aegypti to humans. Two different Wolbachia strains have been released to date. The primary

  16. Mosquito activity of a series of chalcones and 2-pyrazoline derivatives against Aedes aegypti

    Science.gov (United States)

    Aedes aegypti (L.) (Diptera: Culicidae) transmit pathogens to humans, leading to diseases such as yellow fever and dengue fever. Repellents and insecticides are two common interventions to reduce mosquito biting and thereby disease risk. However, overreliance on a chemical or class of chemicals c...

  17. Winter refuge for Aedes aegypti and Ae. albopictus mosquitoes in Hanoi during Winter.

    Science.gov (United States)

    Tsunoda, Takashi; Cuong, Tran Chi; Dong, Tran Duc; Yen, Nguyen Thi; Le, Nguyen Hoang; Phong, Tran Vu; Minakawa, Noboru

    2014-01-01

    Dengue occurs throughout the year in Hanoi, Vietnam, despite winter low temperatures density drastically decreased in winter. Aedes aegypti preferred concrete tanks and this preference increased in winter. Even in winter, the lowest water temperature found in concrete tanks was >14°C, exceeding the developmental zero point of Ae. aegypti. Although jars, drums and concrete tanks were the dominant containers previously (1994-97) in Hanoi, currently the percentage of residences with concrete tanks was still high while jars and drums were quite low. Our study showed that concrete tanks with broken lids allowing mosquitoes access were important winter refuge for Ae. aegypti. We also indicate a concern about concrete tanks serving as foci for Ae. aegypti to expand their distribution in cooler regions.

  18. The Dengue Virus Mosquito Vector Aedes aegypti at High Elevation in México

    Science.gov (United States)

    Lozano-Fuentes, Saul; Hayden, Mary H.; Welsh-Rodriguez, Carlos; Ochoa-Martinez, Carolina; Tapia-Santos, Berenice; Kobylinski, Kevin C.; Uejio, Christopher K.; Zielinski-Gutierrez, Emily; Monache, Luca Delle; Monaghan, Andrew J.; Steinhoff, Daniel F.; Eisen, Lars

    2012-01-01

    México has cities (e.g., México City and Puebla City) located at elevations > 2,000 m and above the elevation ceiling below which local climates allow the dengue virus mosquito vector Aedes aegypti to proliferate. Climate warming could raise this ceiling and place high-elevation cities at risk for dengue virus transmission. To assess the elevation ceiling for Ae. aegypti and determine the potential for using weather/climate parameters to predict mosquito abundance, we surveyed 12 communities along an elevation/climate gradient from Veracruz City (sea level) to Puebla City (∼2,100 m). Ae. aegypti was commonly encountered up to 1,700 m and present but rare from 1,700 to 2,130 m. This finding extends the known elevation range in México by > 300 m. Mosquito abundance was correlated with weather parameters, including temperature indices. Potential larval development sites were abundant in Puebla City and other high-elevation communities, suggesting that Ae. aegypti could proliferate should the climate become warmer. PMID:22987656

  19. The dengue virus mosquito vector Aedes aegypti at high elevation in Mexico.

    Science.gov (United States)

    Lozano-Fuentes, Saul; Hayden, Mary H; Welsh-Rodriguez, Carlos; Ochoa-Martinez, Carolina; Tapia-Santos, Berenice; Kobylinski, Kevin C; Uejio, Christopher K; Zielinski-Gutierrez, Emily; Monache, Luca Delle; Monaghan, Andrew J; Steinhoff, Daniel F; Eisen, Lars

    2012-11-01

    México has cities (e.g., México City and Puebla City) located at elevations > 2,000 m and above the elevation ceiling below which local climates allow the dengue virus mosquito vector Aedes aegypti to proliferate. Climate warming could raise this ceiling and place high-elevation cities at risk for dengue virus transmission. To assess the elevation ceiling for Ae. aegypti and determine the potential for using weather/climate parameters to predict mosquito abundance, we surveyed 12 communities along an elevation/climate gradient from Veracruz City (sea level) to Puebla City (∼2,100 m). Ae. aegypti was commonly encountered up to 1,700 m and present but rare from 1,700 to 2,130 m. This finding extends the known elevation range in México by > 300 m. Mosquito abundance was correlated with weather parameters, including temperature indices. Potential larval development sites were abundant in Puebla City and other high-elevation communities, suggesting that Ae. aegypti could proliferate should the climate become warmer.

  20. The Effects of Pre-Exposure to DEET on the Downstream Blood-Feeding Behaviors of Aedes aegypti Mosquitoes

    Science.gov (United States)

    2016-06-10

    increased their satiety levels. 230 Aedes aegypti mosquitoes can transmit many arboviruses, such as: dengue, chikungunya, 231 yellow fever , or Zika viruses...J. Linthicum. 2011. Laboratory evaluation of the 271 response of Aedes aegypti and Aedes albopictus uninfected and infected with dengue 272 virus to...1 Sugiharto et al.: Aedes aegypti blood- Michael J. Turell 1 feeding after DEET pre-exposure Virology Division, USAMRIID 2 1425 Porter

  1. Analysis of ovary-specific genes in relation to egg maturation and female nutritional condition in the mosquitoes Georgecraigius atropalpus and Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Telang, Aparna; Rechel, Julie A; Brandt, Jessica R; Donnell, David M

    2013-03-01

    Analysis of the reproductive physiology of anautogenous mosquitoes at the molecular level is complicated by the simultaneity of ovarian maturation and the digestion of a blood meal. In contrast to anautogenous mosquitoes, autogenous female mosquitoes can acquire greater nutrient stores as larvae and exhibit higher ovarian production of ecdysteroids at adult eclosion. These features essentially replace the role of a blood meal in provisioning the first batch of eggs and initiating egg development. To gain insight into the process of ovary maturation we first performed a transcript analysis of the obligatory autogenous mosquito Georgecraigius atropalpus (formerly Ochlerotatus atropalpus). We identified ESTs using suppressive subtractive hybridization (SSH) of transcripts from ovaries at critical times during oogenesis in the absence of blood digestion. Preliminary expression studies of genes such as apolipophorin III (APO) and oxysterol binding protein (OSBP) suggested these genes might be cued to female nutritional status. We then applied our findings to the medically important anautogenous mosquito Aedes aegypti. RNAi-based analyses of these genes in Ae. aegypti revealed a reduction in APO transcripts leads to reduced lipid levels in carcass and ovaries and that OSBP may play a role in overall lipid and sterol homeostasis. In addition to expanding our understanding of mosquito ovarian development, the continued use of a comparative approach between autogenous and anautogenous species may provide novel intervention points for the regulation of mosquito egg production. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. On the Seasonal Occurrence and Abundance of the Zika Virus Vector Mosquito Aedes Aegypti in the Contiguous United States

    OpenAIRE

    Monaghan, Andrew J.; Morin, Cory W.; Steinhoff, Daniel F.; Wilhelmi, Olga; Hayden, Mary; Quattrochi, Dale A.; Reiskind, Michael; Lloyd, Alun L.; Smith, Kirk; Schmidt, Chris A.; Scalf, Paige E.; Ernst, Kacey

    2016-01-01

    Introduction: An ongoing Zika virus pandemic in Latin America and the Caribbean has raised concerns that travel-related introduction of Zika virus could initiate local transmission in the United States (U.S.) by its primary vector, the mosquito Aedes aegypti. Methods: We employed meteorologically driven models for 2006-2015 to simulate the potential seasonal abundance of adult Aedes aegypti for fifty cities within or near the margins of its known U.S. range. Mosquito abundance results were an...

  3. Analysis of a ribosomal DNA intergenic spacer region from the yellow fever mosquito, Aedes aegypti.

    Science.gov (United States)

    Wu, C C; Fallon, A M

    1998-02-01

    We have sequenced the 1.8 kb intergenic spacer (IGS) region from an Aedes aegypti ribosomal DNA repeat and have identified conserved functional motifs shared with the related mosquito, Aedes albopictus. Despite the shorter length and greater homogeneity of the Ae. aegypti IGS region, the sequences of two potential RNA polymerase I core promoters and closely associated terminator elements were highly conserved. Primer extension analysis indicated that the predominant transcription initiation site in the Ae. aegypti rDNA repeat unit region lay at or near the A residue at nucleotide position 1003 in the 'upstream' RNA polymerase I promoter. This observation was supported by the higher sequence identity between the upstream promoters in Ae. aegypti and Ae. albopictus, relative to the downstream promoters. In contrast to strong similarities among proximal regulatory elements, the Ae. aegypti IGS sequence upstream of the transcription initiation site lacked the ordered array of contiguous approximately 200 nucleotide subrepeats previously found in the IGS of Ae. albopictus. In Ae. aegypti, only 4 approximately 50 nucleotide R subrepeats separated by unique sequences, followed by 2 approximately 50 nucleotide E subrepeats, occurred upstream of the transcription initiation site. Despite their differences in size and sequence, however, the four Ae. aegypti R subrepeats shared an internal structural organization that included a conserved core with 'spacer' promoters and recombinogenic elements similar to those in the longer Ae. albopictus subrepeats. These observations provide an important basis for further characterization of transcription specificity among mosquito RNA polymerase I promoters and associated regulatory elements, and contribute towards the eventual use of these elements in transgenic applications.

  4. Methods for TALEN Evaluation, Use, and Mutation Detection in the Mosquito Aedes aegypti.

    Science.gov (United States)

    Basu, Sanjay; Aryan, Azadeh; Haac, Mary Etna; Myles, Kevin M; Adelman, Zach N

    2016-01-01

    The generation and study of transgenic Aedes aegypti mosquitoes provides an essential tool for elucidating the complex molecular biology of this important vector. Within the field, genetic manipulation has surpassed the proof of principle stage and is now utilized in both applied and theoretical vector control strategies. The application of new instruments, technologies and techniques allows ever more controlled experiments to be conducted. In this text we describe microinjection of Ae. aegypti embryos in the context of evaluating and performing genomic editing with transcription activator-like effector nucleases (TALENs).

  5. Mathematical model of temephos resistance in Aedes aegypti mosquito population

    Science.gov (United States)

    Aldila, D.; Nuraini, N.; Soewono, E.; Supriatna, A. K.

    2014-03-01

    Aedes aegypti is the main vector of dengue disease in many tropical and sub-tropical countries. Dengue became major public concern in these countries due to the unavailability of vaccine or drugs for dengue disease in the market. Hence, the only way to control the spread of DF and DHF is by controlling the vectors carrying the disease, for instance with fumigation, temephos or genetic manipulation. Many previous studies conclude that Aedes aegypti may develop resistance to many kind of insecticide, including temephos. Mathematical model for transmission of temephos resistance in Aedes aegypti population is discussed in this paper. Nontrivial equilibrium point of the system and the corresponding existence are shown analytically. The model analysis have shown epidemiological trends condition that permits the coexistence of nontrivial equilibrium is given analytically. Numerical results are given to show parameter sensitivity and some cases of worsening effect values for illustrating possible conditions in the field.

  6. Dengue virus type 2 infections of Aedes aegypti are modulated by the mosquito's RNA interference pathway.

    Directory of Open Access Journals (Sweden)

    Irma Sánchez-Vargas

    2009-02-01

    Full Text Available A number of studies have shown that both innate and adaptive immune defense mechanisms greatly influence the course of human dengue virus (DENV infections, but little is known about the innate immune response of the mosquito vector Aedes aegypti to arbovirus infection. We present evidence here that a major component of the mosquito innate immune response, RNA interference (RNAi, is an important modulator of mosquito infections. The RNAi response is triggered by double-stranded RNA (dsRNA, which occurs in the cytoplasm as a result of positive-sense RNA virus infection, leading to production of small interfering RNAs (siRNAs. These siRNAs are instrumental in degradation of viral mRNA with sequence homology to the dsRNA trigger and thereby inhibition of virus replication. We show that although dengue virus type 2 (DENV2 infection of Ae. aegypti cultured cells and oral infection of adult mosquitoes generated dsRNA and production of DENV2-specific siRNAs, virus replication and release of infectious virus persisted, suggesting viral circumvention of RNAi. We also show that DENV2 does not completely evade RNAi, since impairing the pathway by silencing expression of dcr2, r2d2, or ago2, genes encoding important sensor and effector proteins in the RNAi pathway, increased virus replication in the vector and decreased the extrinsic incubation period required for virus transmission. Our findings indicate a major role for RNAi as a determinant of DENV transmission by Ae. aegypti.

  7. Temporal abundance of Aedes aegypti in Manaus, Brazil, measured by two trap types for adult mosquitoes

    Directory of Open Access Journals (Sweden)

    Carolin Marlen Degener

    2014-12-01

    Full Text Available A longitudinal study was conducted in Manaus, Brazil, to monitor changes of adult Aedes aegypti (L. abundance. The objectives were to compare mosquito collections of two trap types, to characterise temporal changes of the mosquito population, to investigate the influence of meteorological variables on mosquito collections and to analyse the association between mosquito collections and dengue incidence. Mosquito monitoring was performed fortnightly using MosquiTRAPs (MQT and BG-Sentinel (BGS traps between December 2008-June 2010. The two traps revealed opposing temporal infestation patterns, with highest mosquito collections of MQTs during the dry season and highest collections of BGS during the rainy seasons. Several meteorological variables were significant predictors of mosquito collections in the BGS. The best predictor was the relative humidity, lagged two weeks (in a positive relationship. For MQT, only the number of rainy days in the previous week was significant (in a negative relationship. The correlation between monthly dengue incidence and mosquito abundance in BGS and MQT was moderately positive and negative, respectively. Catches of BGS traps reflected better the dynamic of dengue incidence. The findings help to understand the effects of meteorological variables on mosquito infestation indices of two different traps for adult dengue vectors in Manaus.

  8. Temporal abundance of Aedes aegypti in Manaus, Brazil, measured by two trap types for adult mosquitoes.

    Science.gov (United States)

    Degener, Carolin Marlen; Ázara, Tatiana Mingote Ferreira de; Roque, Rosemary Aparecida; Codeço, Cláudia Torres; Nobre, Aline Araújo; Ohly, Jörg Johannes; Geier, Martin; Eiras, Álvaro Eduardo

    2014-12-01

    A longitudinal study was conducted in Manaus, Brazil, to monitor changes of adult Aedes aegypti (L.) abundance. The objectives were to compare mosquito collections of two trap types, to characterise temporal changes of the mosquito population, to investigate the influence of meteorological variables on mosquito collections and to analyse the association between mosquito collections and dengue incidence. Mosquito monitoring was performed fortnightly using MosquiTRAPs (MQT) and BG-Sentinel (BGS) traps between December 2008-June 2010. The two traps revealed opposing temporal infestation patterns, with highest mosquito collections of MQTs during the dry season and highest collections of BGS during the rainy seasons. Several meteorological variables were significant predictors of mosquito collections in the BGS. The best predictor was the relative humidity, lagged two weeks (in a positive relationship). For MQT, only the number of rainy days in the previous week was significant (in a negative relationship). The correlation between monthly dengue incidence and mosquito abundance in BGS and MQT was moderately positive and negative, respectively. Catches of BGS traps reflected better the dynamic of dengue incidence. The findings help to understand the effects of meteorological variables on mosquito infestation indices of two different traps for adult dengue vectors in Manaus.

  9. Repellent and insecticidal efficacy of a new combination of fipronil and permethrin against three mosquito species (Aedes albopictus, Aedes aegypti and Culex pipiens) on dogs.

    Science.gov (United States)

    Fankhauser, Becky; Dumont, Pascal; Hunter, James S; McCall, John W; Kaufmann, Christian; Mathis, Alexander; Young, David R; Carroll, Scott P; McCall, Scott; Chester, S Theodore; Soll, Mark D

    2015-01-30

    Three laboratory studies were conducted to assess the repellent and insecticidal efficacy of a combination of fipronil and permethrin (Frontline Tri- Act/Frontect) against three mosquito species (Aedes albopictus, Aedes aegypti and Culex pipiens) on dogs. In each study, 16 healthy adult dogs were allocated to two groups. Eight dogs were treated with the new topical spot-on combination of fipronil and permethrin on Day 0 and the other eight dogs served as untreated controls. Each dog was exposed to mosquitoes on Days 1, 7, 14, 21 and 28 (and also on Day 35 in the A. aegypti study). After a 1-h exposure period, all mosquitoes were counted and categorized as live or dead and fed or non-fed. Live mosquitoes were kept in an insectary and observed for mortality counts 4, 24 and 48 h post-exposure (PE) for Aedes spp. and 24 and 48 h PE for C. pipiens. Repellency and insecticidal efficacies were defined as the percent reduction in the number of fed and live mosquitoes, respectively, in the treated group as compared to the untreated control group. Repellency against A. albopictus was ≥93.4% through Day 21 and 86.9% on Day 28. It was ≥91.0% through Day 35 against A. aegypti and ≥90.4% through Day 28 against C. pipiens. Insecticidal efficacy against A. albopictus was ≥97.1% at 24 h PE from Day 7 to Day 28. It was ≥98.0% for the first 3 weeks and still 75.7% on Day 35 against A. aegypti at 24 h PE. For C. pipiens, insecticidal efficacy ranged from 93.8% (Day 7) to 30.9% (Day 28) at 48 h PE. A single topical administration of the combination of fipronil and permethrin provides repellency against mosquitoes on dogs for at least 4 weeks. The product may therefore significantly reduce the potential for the transmission of vector-borne pathogens through the inhibition of mosquito feeding, as well as the discomfort associated with mosquito bites. Moreover, mosquito mortality was induced by contact with the treated dogs, which could aid in the control of mosquitoes, and

  10. Blood-Feeding Induces Reversible Functional Changes in Flight Muscle Mitochondria of Aedes aegypti Mosquito

    Science.gov (United States)

    Gonçalves, Renata L. S.; Machado, Ana Carolina L.; Paiva-Silva, Gabriela O.; Sorgine, Marcos H. F.; Momoli, Marisa M.; Oliveira, Jose Henrique M.; Vannier-Santos, Marcos A.; Galina, Antonio; Oliveira, Pedro L.; Oliveira, Marcus F.

    2009-01-01

    Background Hematophagy poses a challenge to blood-feeding organisms since products of blood digestion can exert cellular deleterious effects. Mitochondria perform multiple roles in cell biology acting as the site of aerobic energy-transducing pathways, and also an important source of reactive oxygen species (ROS), modulating redox metabolism. Therefore, regulation of mitochondrial function should be relevant for hematophagous arthropods. Here, we investigated the effects of blood-feeding on flight muscle (FM) mitochondria from the mosquito Aedes aegypti, a vector of dengue and yellow fever. Methodology/Principal Findings Blood-feeding caused a reversible reduction in mitochondrial oxygen consumption, an event that was parallel to blood digestion. These changes were most intense at 24 h after blood meal (ABM), the peak of blood digestion, when oxygen consumption was inhibited by 68%. Cytochromes c and a+a 3 levels and cytochrome c oxidase activity of the electron transport chain were all reduced at 24 h ABM. Ultrastructural and molecular analyses of FM revealed that mitochondria fuse upon blood meal, a condition related to reduced ROS generation. Consistently, BF induced a reversible decrease in mitochondrial H2O2 formation during blood digestion, reaching their lowest values at 24 h ABM where a reduction of 51% was observed. Conclusion Blood-feeding triggers functional and structural changes in hematophagous insect mitochondria, which may represent an important adaptation to blood feeding. PMID:19924237

  11. Environmental and genetic factors determine whether the mosquito Aedes aegypti lays eggs without a blood meal.

    Science.gov (United States)

    Ariani, Cristina V; Smith, Sophia C L; Osei-Poku, Jewelna; Short, Katherine; Juneja, Punita; Jiggins, Francis M

    2015-04-01

    Some mosquito strains or species are able to lay eggs without taking a blood meal, a trait named autogeny. This may allow populations to persist through times or places where vertebrate hosts are scarce. Autogenous egg production is highly dependent on the environment in some species, but the ideal conditions for its expression in Aedes aegypti mosquitoes are unknown. We found that 3.2% of females in a population of Ae. aegypti from Kenya were autogenous. Autogeny was strongly influenced by temperature, with many more eggs laid at 28°C compared with 22°C. Good nutrition in larval stages and feeding on higher concentrations of sugar solution during the adult stage both result in more autogenous eggs being produced. The trait also has a genetic basis, as not all Ae. aegypti genotypes can lay autogenously. We conclude that Ae. aegypti requires a favorable environment and a suitable genotype to be able to lay eggs without a blood meal. © The American Society of Tropical Medicine and Hygiene.

  12. Extensive Genetic Differentiation between Homomorphic Sex Chromosomes in the Mosquito Vector, Aedes aegypti

    OpenAIRE

    Fontaine, Albin; Filipović, Igor; Fansiri, Thanyalak; Hoffmann, Ary A.; Cheng, Changde; Kirkpatrick, Mark; Rašić, Gordana; Lambrechts, Louis

    2017-01-01

    Abstract Mechanisms and evolutionary dynamics of sex-determination systems are of particular interest in insect vectors of human pathogens like mosquitoes because novel control strategies aim to convert pathogen-transmitting females into nonbiting males, or rely on accurate sexing for the release of sterile males. In Aedes aegypti, the main vector of dengue and Zika viruses, sex determination is governed by a dominant male-determining locus, previously thought to reside within a small, nonrec...

  13. Larvicidal and repellent effect of some Tribulus terrestris L., (Zygophyllaceae extracts against the dengue fever mosquito, Aedes aegypti (Diptera: Culicidae

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    Tarek M.Y. El-Sheikh

    2016-01-01

    Full Text Available Aedes aegypti transmits etiologic agents of yellow fever and dengue. Vaccine for dengue virus is not available and vector control is essential to minimize dengue incidence. The larvicidal and repellent effect of the crude ethanol, acetone and petroleum ether extract leaves of Tribulus terrestris, against 3rd instar larvae and adults of mosquito, Ae. aegypti the vector of dengue fever was evaluated. The efficacy of petroleum ether extract seemed to be more effective with LC50 64.6 ppm followed by acetone extract with LC50 173.2 ppm and finally ethanolic extract with LC50 376.4 ppm. Moreover, the acetone and petroleum ether extracts exerted a highly delayed toxic effect on the pupae and adults resulted from treated larvae, where the pupal mortality was 57.1% and 100% at concentrations 400 and 100 ppm, respectively. Also, the petroleum ether and acetone extracts showed reduction effects on adult emergence. The repellent action of the plant extracts tested was varied depending on the solvent used in extraction and the dose of the extract. The most effective plant extract that evoked 100% repellency or biting deterrence was petroleum ether extract at a dose of 1.5 mg/cm2 compared with 100% repellency for commercial formulation, N,N-diethyl-3-methylbenzamide (DEET at the same dose. Hence, these extracts can be used as an effective alternative to the existing synthetic pesticides for the control of Ae. aegypti.

  14. Technical evaluation of a potential release of OX513A Aedes aegypti mosquitoes on the island of Saba

    NARCIS (Netherlands)

    Glandorf DCM; GBV; M&V

    2017-01-01

    The mosquito Aedes aegypti transmits viruses that cause diseases such as dengue, chikungunya and zika. Measures are taken to control the mosquito since these infectious diseases represent a significant health problem. This is the case on the island of Saba, a Dutch Caribbean island. In order to

  15. Heritable CRISPR/Cas9-mediated genome editing in the yellow fever mosquito, Aedes aegypti.

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    Shengzhang Dong

    Full Text Available In vivo targeted gene disruption is a powerful tool to study gene function. Thus far, two tools for genome editing in Aedes aegypti have been applied, zinc-finger nucleases (ZFN and transcription activator-like effector nucleases (TALEN. As a promising alternative to ZFN and TALEN, which are difficult to produce and validate using standard molecular biological techniques, the clustered regularly interspaced short palindromic repeats/CRISPR-associated sequence 9 (CRISPR/Cas9 system has recently been discovered as a "do-it-yourself" genome editing tool. Here, we describe the use of CRISPR/Cas9 in the mosquito vector, Aedes aegypti. In a transgenic mosquito line expressing both Dsred and enhanced cyan fluorescent protein (ECFP from the eye tissue-specific 3xP3 promoter in separated but tightly linked expression cassettes, we targeted the ECFP nucleotide sequence for disruption. When supplying the Cas9 enzyme and two sgRNAs targeting different regions of the ECFP gene as in vitro transcribed mRNAs for germline transformation, we recovered four different G1 pools (5.5% knockout efficiency where individuals still expressed DsRed but no longer ECFP. PCR amplification, cloning, and sequencing of PCR amplicons revealed indels in the ECFP target gene ranging from 2-27 nucleotides. These results show for the first time that CRISPR/Cas9 mediated gene editing is achievable in Ae. aegypti, paving the way for further functional genomics related studies in this mosquito species.

  16. QTL mapping of genome regions controlling temephos resistance in larvae of the mosquito Aedes aegypti.

    Science.gov (United States)

    Reyes-Solis, Guadalupe Del Carmen; Saavedra-Rodriguez, Karla; Suarez, Adriana Flores; Black, William C

    2014-10-01

    The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Temephos is an organophosphate insecticide used globally to suppress Ae. aegypti larval populations but resistance has evolved in many locations. Quantitative Trait Loci (QTL) controlling temephos survival in Ae. aegypti larvae were mapped in a pair of F3 advanced intercross lines arising from temephos resistant parents from Solidaridad, México and temephos susceptible parents from Iquitos, Peru. Two sets of 200 F3 larvae were exposed to a discriminating dose of temephos and then dead larvae were collected and preserved for DNA isolation every two hours up to 16 hours. Larvae surviving longer than 16 hours were considered resistant. For QTL mapping, single nucleotide polymorphisms (SNPs) were identified at 23 single copy genes and 26 microsatellite loci of known physical positions in the Ae. aegypti genome. In both reciprocal crosses, Multiple Interval Mapping identified eleven QTL associated with time until death. In the Solidaridad×Iquitos (SLD×Iq) cross twelve were associated with survival but in the reciprocal IqxSLD cross, only six QTL were survival associated. Polymorphisms at acetylcholine esterase (AchE) loci 1 and 2 were not associated with either resistance phenotype suggesting that target site insensitivity is not an organophosphate resistance mechanism in this region of México. Temephos resistance is under the control of many metabolic genes of small effect and dispersed throughout the Ae. aegypti genome.

  17. Bacteria as a source of oviposition attractant for Aedes aegypti mosquitoes.

    Science.gov (United States)

    Arbaoui, A A; Chua, T H

    2014-03-01

    Since a safe and effective mass vaccination program against dengue fever is not presently available, a good way to prevent and control dengue outbreaks depends mainly on controlling the mosquito vectors. Aedes aegypti mosquito populations can be monitored and reduced by using ovitraps baited with organic infusions. A series of laboratory experiments were conducted which demonstrated that the bacteria in bamboo leaf infusion produce volatile attractants and contact chemical stimulants attractive to the female mosquitoes. The results showed that the female mosquitoes laid most of their eggs (59.9 ± 8.1 vs 2.9 ± 2.8 eggs, P<0.001) in bamboo leaf infusions when compared to distilled water. When the fresh infusion was filtered with a 0.45 μm filter membrane, the female mosquitoes laid significantly more eggs (64.1 ± 6.6 vs 4.9 ± 2.6 eggs, P<0.001) in unfiltered infusion. However when a 0.8 μm filter membrane was used, the female laid significantly more eggs (62.0 ± 4.3 vs 10.1 ± 7.8 eggs, P<0.001) in filtrate compared to a solution containing the residue. We also found that a mixture of bacteria isolated from bamboo leaf infusion serve as potent oviposition stimulants for gravid Aedes mosquitoes. Aedes aegypti laid significantly more eggs (63.3 ± 6.5 vs 3.1 ± 2.4 eggs, P<0.001) in bacteria suspension compared to sterile R2A medium. Our results suggest microbial activity has a role in the production of odorants that mediate the oviposition response of gravid mosquitoes.

  18. Mosquito larvicidal activity of seaweeds extracts against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus

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    Mohamed Yacoob Syed Ali

    2013-06-01

    Full Text Available Objective: To identify the larvicidal activity of the seaweed extracts against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus Methods: Seaweed extracts of Ulva lactuca, Caulerpa racemosa (C. racemosa, Sargassum microystum, Caulerpa scalpelliformis, Gracilaria corticata, Turbinaria decurrens, Turbinaria conoides and Caulerpa toxifolia were dissolved in DMSO to prepare a graded series of concentration. The test for the larvicidal effect of seaweeds against mosquitos larvae was conducted in accordance with the WHO standard method. Batches of 25 early 4th instar larvae of three mosquitoes were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (10-100 µg. Each experiment was conducted with triplicate with concurrent a control group. Results: Among the seaweeds extract, C. racemosa showed toxicity against 4th instar larvae of Aedes aegypti, Culex quinquefasciatus, Anopheles stephensi with equivalent LC 50 value (0.055 6依0.010 3 µg/mL, (0.067 5依0.136 0 µg/mL and (0.066 1 依0.007 6 µg/mL, respectively. Conclusions: The present study concluded that, the mosquito larvicidal property of C. racemosa might be the prospective alternative source to control the mosquitoes.

  19. Quantitative trait loci mapping of genome regions controlling permethrin resistance in the mosquito Aedes aegypti.

    Science.gov (United States)

    Saavedra-Rodriguez, Karla; Strode, Clare; Flores Suarez, Adriana; Fernandez Salas, Ildefonso; Ranson, Hilary; Hemingway, Janet; Black, William C

    2008-10-01

    The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Permethrin is an insecticide used to suppress Ae. aegypti adult populations but metabolic and target site resistance to pyrethroids has evolved in many locations worldwide. Quantitative trait loci (QTL) controlling permethrin survival in Ae. aegypti were mapped in an F(3) advanced intercross line. Parents came from a collection of mosquitoes from Isla Mujeres, México, that had been selected for permethrin resistance for two generations and a reference permethrin-susceptible strain originally from New Orleans. Following a 1-hr permethrin exposure, 439 F(3) adult mosquitoes were phenotyped as knockdown resistant, knocked down/recovered, or dead. For QTL mapping, single nucleotide polymorphisms (SNPs) were identified at 22 loci with potential antixenobiotic activity including genes encoding cytochrome P450s (CYP), esterases (EST), or glutathione transferases (GST) and at 12 previously mapped loci. Seven antixenobiotic genes mapped to chromosome I, six to chromosome II, and nine to chromosome III. Two QTL of major effect were detected on chromosome III. One corresponds with a SNP previously associated with permethrin resistance in the para sodium channel gene and the second with the CCEunk7o esterase marker. Additional QTL but of relatively minor effect were also found. These included two sex-linked QTL on chromosome I affecting knockdown and recovery and a QTL affecting survival and recovery. On chromosome II, one QTL affecting survival and a second affecting recovery were detected. The patterns confirm that mutations in the para gene cause target-site insensitivity and are the major source of permethrin resistance but that other genes dispersed throughout the genome contribute to recovery and survival of mosquitoes following permethrin exposure.

  20. Dynamic remodeling of lipids coincides with dengue virus replication in the midgut of Aedes aegypti mosquitoes.

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    Nunya Chotiwan

    2018-02-01

    Full Text Available We describe the first comprehensive analysis of the midgut metabolome of Aedes aegypti, the primary mosquito vector for arboviruses such as dengue, Zika, chikungunya and yellow fever viruses. Transmission of these viruses depends on their ability to infect, replicate and disseminate from several tissues in the mosquito vector. The metabolic environments within these tissues play crucial roles in these processes. Since these viruses are enveloped, viral replication, assembly and release occur on cellular membranes primed through the manipulation of host metabolism. Interference with this virus infection-induced metabolic environment is detrimental to viral replication in human and mosquito cell culture models. Here we present the first insight into the metabolic environment induced during arbovirus replication in Aedes aegypti. Using high-resolution mass spectrometry, we have analyzed the temporal metabolic perturbations that occur following dengue virus infection of the midgut tissue. This is the primary site of infection and replication, preceding systemic viral dissemination and transmission. We identified metabolites that exhibited a dynamic-profile across early-, mid- and late-infection time points. We observed a marked increase in the lipid content. An increase in glycerophospholipids, sphingolipids and fatty acyls was coincident with the kinetics of viral replication. Elevation of glycerolipid levels suggested a diversion of resources during infection from energy storage to synthetic pathways. Elevated levels of acyl-carnitines were observed, signaling disruptions in mitochondrial function and possible diversion of energy production. A central hub in the sphingolipid pathway that influenced dihydroceramide to ceramide ratios was identified as critical for the virus life cycle. This study also resulted in the first reconstruction of the sphingolipid pathway in Aedes aegypti. Given conservation in the replication mechanisms of several

  1. Habitat productivity and pyrethroid susceptibility status of Aedes aegypti mosquitoes in Dar es Salaam, Tanzania.

    Science.gov (United States)

    Mathias, Leah; Baraka, Vito; Philbert, Anitha; Innocent, Ester; Francis, Filbert; Nkwengulila, Gamba; Kweka, Eliningaya J

    2017-06-09

    Aedes aegypti (Diptera: Culicidae) is the main vector of the dengue virus globally. Dengue vector control is mainly based on reducing the vector population through interventions, which target potential breeding sites. However, in Tanzania, little is known about this vector's habitat productivity and insecticide susceptibility status to support evidence-based implementation of control measures. The present study aimed at assessing the productivity and susceptibility status of A. aegypti mosquitoes to pyrethroid-based insecticides in Dar es Salaam, Tanzania. An entomological assessment was conducted between January and July 2015 in six randomly selected wards in Dar es Salaam, Tanzania. Habitat productivity was determined by the number of female adult A. aegypti mosquitoes emerged per square metre. The susceptibility status of adult A. aegypti females after exposure to 0.05% deltamethrin, 0.75% permethrin and 0.05% lambda-cyhalothrin was evaluated using the standard WHO protocols. Mortality rates were recorded after 24 h exposure and the knockdown effect was recorded at the time points of 10, 15, 20, 30, 40, 50 and 60 min to calculate the median knockdown times (KDT 50 and KDT 95 ). The results suggest that disposed tyres had the highest productivity, while water storage tanks had the lowest productivity among the breeding habitats Of A. aegypti mosquitoes. All sites demonstrated reduced susceptibility to deltamethrin (0.05%) within 24 h post exposure, with mortalities ranging from 86.3 ± 1.9 (mean ± SD) to 96.8 ± 0.9 (mean ± SD). The lowest and highest susceptibilities were recorded in Mikocheni and Sinza wards, respectively. Similarly, all sites demonstrated reduced susceptibility permethrin (0.75%) ranging from 83.1 ± 2.1% (mean ± SD) to 96.2 ± 0.9% (mean ± SD), in Kipawa and Sinza, respectively. Relatively low mortality rates were observed in relation to lambda-cyhalothrin (0.05%) at all sites, ranging from 83.1 ± 0

  2. Targeting gene expression to the female larval fat body of transgenic Aedes aegypti mosquitoes.

    Science.gov (United States)

    Totten, D C; Vuong, M; Litvinova, O V; Jinwal, U K; Gulia-Nuss, M; Harrell, R A; Beneš, H

    2013-02-01

    As the fat body is a critical tissue for mosquito development, metamorphosis, immune and reproductive system function, the characterization of regulatory modules targeting gene expression to the female mosquito fat body at distinct life stages is much needed for multiple, varied strategies for controlling vector-borne diseases such as dengue and malaria. The hexameric storage protein, Hexamerin-1.2, of the mosquito Aedes atropalpus is female-specific and uniquely expressed in the fat body of fourth instar larvae and young adults. We have identified in the Hex-1.2 gene, a short regulatory module that directs female-, tissue-, and stage-specific lacZ reporter gene expression using a heterologous promoter in transgenic lines of the dengue vector Aedes aegypti. Male transgenic larvae and pupae of one line expressed no Escherichia coli β-galactosidase or transgene product; in two other lines reporter gene activity was highly female-biased. All transgenic lines expressed the reporter only in the fat body; however, lacZ mRNA levels were no different in males and females at any stage examined, suggesting that the gene regulatory module drives female-specific expression by post-transcriptional regulation in the heterologous mosquito. This regulatory element from the Hex-1.2 gene thus provides a new molecular tool for transgenic mosquito control as well as functional genetic analysis in aedine mosquitoes. © 2012 Royal Entomological Society.

  3. Pyrethroid resistance in Aedes aegypti and Aedes albopictus: Important mosquito vectors of human diseases.

    Science.gov (United States)

    Smith, Letícia B; Kasai, Shinji; Scott, Jeffrey G

    2016-10-01

    Aedes aegypti and A. albopictus mosquitoes are vectors of important human disease viruses, including dengue, yellow fever, chikungunya and Zika. Pyrethroid insecticides are widely used to control adult Aedes mosquitoes, especially during disease outbreaks. Herein, we review the status of pyrethroid resistance in A. aegypti and A. albopictus, mechanisms of resistance, fitness costs associated with resistance alleles and provide suggestions for future research. The widespread use of pyrethroids has given rise to many populations with varying levels of resistance worldwide, albeit with substantial geographical variation. In adult A. aegypti and A. albopictus, resistance levels are generally lower in Asia, Africa and the USA, and higher in Latin America, although there are exceptions. Susceptible populations still exist in several areas of the world, particularly in Asia and South America. Resistance to pyrethroids in larvae is also geographically widespread. The two major mechanisms of pyrethroid resistance are increased detoxification due to P450-monooxygenases, and mutations in the voltage sensitive sodium channel (Vssc) gene. Several P450s have been putatively associated with insecticide resistance, but the specific P450s involved are not fully elucidated. Pyrethroid resistance can be due to single mutations or combinations of mutations in Vssc. The presence of multiple Vssc mutations can lead to extremely high levels of resistance. Suggestions for future research needs are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Effects of intraspecific larval competition on adult longevity in the mosquitoes Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Reiskind, M H; Lounibos, L P

    2009-03-01

    Larval competition is common in container-breeding mosquitoes. The impact of competition on larval growth has been thoroughly examined and findings that larval competition can lead to density-dependent effects on adult body size have been documented. The effects of larval competition on adult longevity have been less well explored. The effects of intraspecific larval densities on the longevity of adults maintained under relatively harsh environmental conditions were tested in the laboratory by measuring the longevity of adult Aedes aegypti (L.) and Aedes albopictus (Skuse) (Diptera: Culicidae) that had been reared under a range of larval densities and subsequently maintained in high- or low-humidity regimes (85% or 35% relative humidity [RH], respectively) as adults. We found significant negative effects of competition on adult longevity in Ae. aegypti, but not in Ae. albopictus. Multivariate analysis of variance suggested that the negative effect of the larval environment on the longevity of Ae. aegypti adults was most strongly associated with increased development time and decreased wing length as adults. Understanding how larval competition affects adult longevity under a range of environmental conditions is important in establishing the relationship between models of mosquito population regulation and epidemiological models of vector-borne disease transmission.

  5. Molecular studies with Aedes (Stegomyia) aegypti (Linnaeus, 1762), mosquito transmitting the dengue virus.

    Science.gov (United States)

    Pereira, Luciana Patrícia Lima Alves; Brito, Maria Cristiane Aranha; Araruna, Felipe Bastos; de Andrade, Marcelo Souza; Moraes, Denise Fernandes Coutinho; Borges, Antônio Carlos Romão; do Rêgo Barros Pires Leal, Emygdia Rosa

    2017-08-01

    Dengue is an infectious viral disease, which can present a wide clinical picture, ranging from oligo or asymptomatic forms, to bleeding and shock, and can progress to death. The disease problem has increased in recent years, especially in urban and suburban areas of tropical and subtropical regions. There are five dengue viruses, called serotypes (DEN-1, DEN-2, DEN-3, DEN-4, and DEN-5), which belong to the Flaviviridae family and are transmitted to humans through infected mosquito bites, with the main vector the Aedes aegypti mosquito (Linnaeus, 1762). Studies performed with Ae. aegypti, aimed at their identification and analysis of their population structure, are fundamental to improve understanding of the epidemiology of dengue, as well for the definition of strategic actions that reduce the transmission of this disease. Therefore, considering the importance of such research to the development of programs to combat dengue, the present review considers the techniques used for the molecular identification, and evaluation of the genetic variability of Ae. aegypti.

  6. Spatial mapping of gene expression in the salivary glands of the dengue vector mosquito, aedes aegypti

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    Paolucci Pimenta Paulo

    2011-01-01

    Full Text Available Abstract Background Aedes aegypti mosquitoes are the main vectors of dengue viruses to humans. Understanding their biology and interactions with the pathogen are prerequisites for development of dengue transmission control strategies. Mosquito salivary glands are organs involved directly in pathogen transmission to vertebrate hosts. Information on the spatial distribution of gene expression in these organs is expected to assist in the development of novel disease control strategies, including those that entail the release of transgenic mosquitoes with impaired vector competence. Results We report here the hybridization in situ patterns of 30 transcripts expressed in the salivary glands of adult Ae. aegypti females. Distinct spatial accumulation patterns were identified. The products of twelve genes are localized exclusively in the proximal-lateral lobes. Among these, three accumulate preferentially in the most anterior portion of the proximal-lateral lobe. This pattern revealed a salivary gland cell type previously undescribed in Ae. aegypti, which was validated by transmission electron microscopy. Five distinct gene products accumulate in the distal-lateral lobes and another five localize in the medial lobe. Seven transcripts are found in the distal-lateral and medial lobes. The transcriptional product of one gene accumulates in proximal- and distal-lateral lobes. Seven genes analyzed by quantitative PCR are expressed constitutively. The most abundant salivary gland transcripts are those localized within the proximal-lateral lobes, while previous work has shown that the distal-lateral lobes are the most active in protein synthesis. This incongruity suggests a role for translational regulation in mosquito saliva production. Conclusions Transgenic mosquitoes with reduced vector competence have been proposed as tools for the control of dengue virus transmission. Expression of anti-dengue effector molecules in the distal-lateral lobes of Ae

  7. Differential Gene Expression from Midguts of Refractory and Susceptible Lines of the Mosquito, Aedes aegypti, Infected with Dengue-2 Virus

    OpenAIRE

    Bar?n, Olga L.; Ursic-Bedoya, Raul J.; Lowenberger, Carl A.; Ocampo, Clara B.

    2010-01-01

    Suppressive subtractive hybridization was used to evaluate the differential expression of midgut genes of feral populations of Aedes aegypti (Diptera: Culicidae) from Colombia that are naturally refractory or susceptible to Dengue-2 virus infection. A total of 165 differentially expressed sequence tags (ESTs) were identified in the subtracted libraries. The analysis showed a higher number of differentially expressed genes in the susceptible Ae. aegypti individuals than the refractory mosquito...

  8. Native Argentinean cyclopoids (Crustacea: Copepoda as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae mosquitoes

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    María C Tranchida

    2009-12-01

    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

  9. Are vectors able to learn about their hosts? A case study with Aedes aegypti mosquitoes

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    Alonso Wladimir J

    2003-01-01

    Full Text Available The way in which vectors distribute themselves amongst their hosts has important epidemiological consequences. While the role played by active host choice is largely unquestioned, current knowledge relates mostly to the innate response of vectors towards stimuli signalling the presence or quality of their hosts. Many of those cues, however, can be unpredictable, and therefore prevent the incorporation of the appropriate response into the vector's behavioural repertoire unless some sort of associative learning is possible. We performed a wide range of laboratory experiments to test the learning abilities of the mosquito, Aedes aegypti. Mosquitoes were exposed to choice procedures in (1 an olfactomenter and (2 a 'visual arena'. Our goal was to determine whether the mosquitoes were able to associate unconditional stimuli (blood feeding, human breath, vibration and electrical shock with particular odours (citral, carvone, citronella oil and eugenol and visual patterns (horizontal or vertical black bars to which they had been previously observed to be responsive. We found no evidence supporting the hypothesis that associative learning abilities are present in adult Ae. aegypti. We discuss the possibilities that the assays employed were either inappropriate or insufficient to detect associative learning, or that associative learning is not possible in this species.

  10. Rhodopsin coexpression in UV photoreceptors of Aedes aegypti and Anopheles gambiae mosquitoes.

    Science.gov (United States)

    Hu, Xiaobang; Leming, Matthew T; Whaley, Michelle A; O'Tousa, Joseph E

    2014-03-15

    Differential rhodopsin gene expression within specialized R7 photoreceptor cells divides the retinas of Aedes aegypti and Anopheles gambiae mosquitoes into distinct domains. The two species express the rhodopsin orthologs Aaop8 and Agop8, respectively, in a large subset of these R7 photoreceptors that function as ultraviolet receptors. We show here that a divergent subfamily of mosquito rhodopsins, Aaop10 and Agop10, is coexpressed in these R7 photoreceptors. The properties of the A. aegypti Aaop8 and Aaop10 rhodopsins were analyzed by creating transgenic Drosophila expressing these rhodopsins. Electroretinogram recordings, and spectral analysis of head extracts, obtained from the Aaop8 strain confirmed that Aaop8 is an ultraviolet-sensitive rhodopsin. Aaop10 was poorly expressed and capable of eliciting only small and slow light responses in Drosophila photoreceptors, and electroretinogram analysis suggested that it is a long-wavelength rhodopsin with a maximal sensitivity near 500 nm. Thus, coexpression of Aaop10 rhodopsin with Aaop8 rhodopsin has the potential to modify the spectral properties of mosquito ultraviolet receptors. Retention of Op10 rhodopsin family members in the genomes of Drosophila species suggests that this rhodopsin family may play a conserved role in insect vision.

  11. Rhythms and synchronization patterns in gene expression in the Aedes aegypti mosquito

    Directory of Open Access Journals (Sweden)

    Carlson Jonathan O

    2011-03-01

    Full Text Available Abstract Background Aedes aegypti is arguably the most studied of all mosquito species in the laboratory and is the primary vector of both Dengue and Yellow Fever flaviviruses in the field. A large number of transcriptional studies have been made in the species and these usually report transcript quantities observed at a certain age or stage of development. However, circadian oscillation is an important characteristic of gene expression in many animals and plants, modulating both their physiology and behavior. Circadian gene expression in mosquito species has been previously reported but for only a few genes directly involved in the function of the molecular clock. Results Herein we analyze the transcription profiles of 21,494 messenger RNAs using an Ae. aegypti Agilent® microarray. Transcripts were quantified in adult female heads at 24 hours and then again at 72 hours and eight subsequent time points spaced four hours apart. We document circadian rhythms in multiple molecular pathways essential for growth, development, immune response, detoxification/pesticide resistance. Circadian rhythms were also noted in ribosomal protein genes used for normalization in reverse transcribed PCR (RT-PCR to determine transcript abundance. We report pervasive oscillations and intricate synchronization patterns relevant to all known biological pathways. Conclusion These results argue strongly that transcriptional analyses either need to be made over time periods rather than confining analyses to a single time point or development stage or exceptional care needs to be made to synchronize all mosquitoes to be analyzed and compared among treatment groups.

  12. Development of a mosquito attractant blend of small molecules against host-seeking Aedes aegypti.

    Science.gov (United States)

    Saratha, R; Mathew, Nisha

    2016-04-01

    A mosquito's dependence on olfaction in the hunt for human host could be efficiently exploited to protect humans from mosquito bites. The present study is undertaken to make the most attractant compound blend for Aedes aegypti mosquitoes to lure them to traps. Eleven molecules (M1-M11) at different dilutions were screened for attractancy against non-blood-fed adult female mosquitoes in an olfactometer. The results showed that the attractancy was dependent on both the chemical nature of the molecule and the strength of the odor. Out of 11 molecules screened, 9 showed significant attractancy (P attractancy was in the order of M11 > M7 > M6 > M10 > M9 > M3 > M2 > M1 > M4 with attractancy indices (AIs) 86.11, 55.93, 55.17, 54, 52.94, 52, 50, 43.64, and 32, respectively, at the optimum dilutions. Seven blends (I-VII) were made and were screened for attractancy against Ae. aegypti. All the blends showed significant attractancy (P attractancy was in the order of blend VII > III > IV > I > VI > V > II with AIs 96.63, 89.19, 65, 57.89, 56.1, 47.13, and 44.44, respectively. Among the seven blends, blend VII with constituent molecules M6, M9, M10, and M11 is the most promising with an AI value of 96.63. This blend will be useful in luring the host-seeking mosquitoes to traps. The field efficacy of these attractant blends may be explored in the future.

  13. On the Seasonal Occurrence and Abundance of the Zika Virus Vector Mosquito Aedes Aegypti in the Contiguous United States.

    Science.gov (United States)

    Monaghan, Andrew J; Morin, Cory W; Steinhoff, Daniel F; Wilhelmi, Olga; Hayden, Mary; Quattrochi, Dale A; Reiskind, Michael; Lloyd, Alun L; Smith, Kirk; Schmidt, Chris A; Scalf, Paige E; Ernst, Kacey

    2016-03-16

    An ongoing Zika virus pandemic in Latin America and the Caribbean has raised concerns that travel-related introduction of Zika virus could initiate local transmission in the United States (U.S.) by its primary vector, the mosquito Aedes aegypti. We employed meteorologically driven models for 2006-2015 to simulate the potential seasonal abundance of adult Aedes aegypti for fifty cities within or near the margins of its known U.S. range. Mosquito abundance results were analyzed alongside travel and socioeconomic factors that are proxies of viral introduction and vulnerability to human-vector contact.     Meteorological conditions are largely unsuitable for Aedes aegypti over the U.S. during winter months (December-March), except in southern Florida and south Texas where comparatively warm conditions can sustain low-to-moderate potential mosquito abundance. Meteorological conditions are suitable for Aedes aegypti across all fifty cities during peak summer months (July-September), though the mosquito has not been documented in all cities. Simulations indicate the highest mosquito abundance occurs in the Southeast and south Texas where locally acquired cases of Aedes-transmitted viruses have been reported previously. Cities in southern Florida and south Texas are at the nexus of high seasonal suitability for Aedes aegypti and strong potential for travel-related virus introduction. Higher poverty rates in cities along the U.S.-Mexico border may correlate with factors that increase human exposure to Aedes aegypti.     Our results can inform baseline risk for local Zika virus transmission in the U.S. and the optimal timing of vector control activities, and underscore the need for enhanced surveillance for Aedes mosquitoes and Aedes-transmitted viruses.

  14. Engineering blood meal-activated systemic immunity in the yellow fever mosquito, Aedes aegypti

    Science.gov (United States)

    Kokoza, Vladimir; Ahmed, Abduelaziz; Cho, Wen-Long; Jasinskiene, Nijole; James, Anthony A.; Raikhel, Alexander

    2000-01-01

    Progress in molecular genetics makes possible the development of alternative disease control strategies that target the competence of mosquitoes to transmit pathogens. We tested the regulatory region of the vitellogenin (Vg) gene of Aedes aegypti for its ability to express potential antipathogen factors in transgenic mosquitoes. Hermes-mediated transformation was used to integrate a 2.1-kb Vg-promoter fragment driving the expression of the Defensin A (DefA) coding region, one of the major insect immune factors. PCR amplification of genomic DNA and Southern blot analyses, carried out through the ninth generation, showed that the Vg-DefA transgene insertion was stable. The Vg-DefA transgene was strongly activated in the fat body by a blood meal. The mRNA levels reached a maximum at 24-h postblood meal, corresponding to the peak expression time of the endogenous Vg gene. High levels of transgenic defensin were accumulated in the hemolymph of bloodfed female mosquitoes, persisting for 20–22 days after a single blood feeding. Purified transgenic defensin showed antibacterial activity comparable to that of defensin isolated from bacterially challenged control mosquitoes. Thus, we have been able to engineer the genetically stable transgenic mosquito with an element of systemic immunity, which is activated through the blood meal-triggered cascade rather than by infection. This work represents a significant step toward the development of molecular genetic approaches to the control of vector competence in pathogen transmission. PMID:10908672

  15. Repellent Action Of Neem (Azadiracta India Seed Oil Against Aedes Aegypti Mosquitoes

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    Hati A K

    1995-01-01

    Full Text Available Neem (Azadiracta India seed oil in appropriate amount when smeared on the surface of the hand showed excellent repellent action against Aedes aegypti mosquitoes. When 1 ml of oil was spread on the hand, with an approximate area of 160 sq cm the percentage of alighting and blood fed mosquitoes in the experimental cages varied from 14 to 78 and 4 to 46 respectively. This percentage decreased to 6 to 18 and 0 to 16 respectively when the amount of oil applied was 1.5 ml. Only 0-4% of the mosquitoes alighted on the skin of which 2% only took the blood meal when 2 ml of the oil was used to cover the hand. In the control cages cent percent of the mosquitoes alighted and sucked blood. The repellent action was directly proportional to the hour of exposure to the oil. It was also observed that even after alighting on a oil- smeared skin a sizeable proportion of mosquitoes were not able to imbibe blood meal. Neem seed oil was non-toxic, non- irritating to skin.

  16. Detection of all four dengue serotypes in Aedes aegypti female mosquitoes collected in a rural area in Colombia

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    Rosalía Pérez-Castro

    2016-04-01

    Full Text Available The Aedes aegypti vector for dengue virus (DENV has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50% and DENV-1 (35%. Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models.

  17. Odonate Nymphs: Generalist Predators and their Potential in the Management of Dengue Mosquito, Aedes aegypti (Diptera: Culicidae

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    Waseem Akram

    2016-01-01

    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. 

  18. How does competition among wild type mosquitoes influence the performance of Aedes aegypti and dissemination of Wolbachia pipientis?

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    Suellen de Oliveira

    2017-10-01

    Full Text Available Wolbachia has been deployed in several countries to reduce transmission of dengue, Zika and chikungunya viruses. During releases, Wolbachia-infected females are likely to lay their eggs in local available breeding sites, which might already be colonized by local Aedes sp. mosquitoes. Therefore, there is an urgent need to estimate the deleterious effects of intra and interspecific larval competition on mosquito life history traits, especially on the duration of larval development time, larval mortality and adult size.Three different mosquito populations were used: Ae. aegypti infected with Wolbachia (wMelBr strain, wild Ae. aegypti and wild Ae. albopictus. A total of 21 treatments explored intra and interspecific larval competition with varying larval densities, species proportions and food levels. Each treatment had eight replicates with two distinct food levels: 0.25 or 0.50 g of Chitosan and fallen avocado leaves. Overall, overcrowding reduced fitness correlates of the three populations. Ae. albopictus larvae presented lower larval mortality, shorter development time to adult and smaller wing sizes than Ae. aegypti. The presence of Wolbachia had a slight positive effect on larval biology, since infected individuals had higher survivorship than uninfected Ae. aegypti larvae.In all treatments, Ae. albopictus outperformed both wild Ae. aegypti and the Wolbachia-infected group in larval competition, irrespective of larval density and the amount of food resources. The major force that can slow down Wolbachia invasion is the population density of wild mosquitoes. Given that Ae. aegypti currently dominates in Rio, in comparison with Ae. albopictus frequency, additional attention must be given to the population density of Ae. aegypti during releases to increase the likelihood of Wolbachia invasion.

  19. Global dynamics of a PDE model for aedes aegypti mosquitoe incorporating female sexual preference

    KAUST Repository

    Parshad, Rana

    2011-01-01

    In this paper we study the long time dynamics of a reaction diffusion system, describing the spread of Aedes aegypti mosquitoes, which are the primary cause of dengue infection. The system incorporates a control attempt via the sterile insect technique. The model incorporates female mosquitoes sexual preference for wild males over sterile males. We show global existence of strong solution for the system. We then derive uniform estimates to prove the existence of a global attractor in L-2(Omega), for the system. The attractor is shown to be L-infinity(Omega) regular and posess state of extinction, if the injection of sterile males is large enough. We also provide upper bounds on the Hausdorff and fractal dimensions of the attractor.

  20. Genomic and evolutionary analyses of Tango transposons in Aedes aegypti, Anopheles gambiae and other mosquito species.

    Science.gov (United States)

    Coy, M R; Tu, Z

    2007-08-01

    Tango is a transposon of the Tc1 family and was originally discovered in the African malaria mosquito, Anopheles gambiae. Here we report a systematic analysis of the genome sequence of the yellow fever mosquito, Aedes aegypti, which uncovered three distinct Tango transposons. We name the only An. gambiae Tango transposon AgTango1 and the three Ae. aegypti Tango elements AeTango1-3. Like AgTango1, AeTango1 and AeTango2 elements both have members that retain characteristics of autonomous elements such as intact open reading frames and terminal inverted repeats (TIRs). AeTango3 is a degenerate transposon with no full-length members. All full-length Tango transposons contain subterminal direct repeats within their TIRs. AgTango1 and AeTango1-3 form a single clade among other Tc1 transposons. Within this clade, AgTango1 and AeTango1 are closely related and share approximately 80% identity at the amino acid level, which exceeds the level of similarity of the majority of host genes in the two species. A survey of Tango in other mosquito species was carried out using degenerate PCR. Tango was isolated and sequenced in all members of the An. gambiae species complex, Aedes albopictus and Ochlerotatus atropalpus. Oc. atropalpus contains a rich diversity of Tango elements, while Tango elements in Ae. albopictus and the An. gambiae species complex all belong to Tango1. No Tango was detected in Culex pipiens quinquefasciatus, Anopheles stephensi, Anopheles dirus, Anopheles farauti or Anopheles albimanus using degenerate PCR. Bioinformatic searches of the Cx. p. quinquefasciatus (~10 x coverage) and An. stephensi (0.33 x coverage) databases also failed to uncover any Tango elements. Although other evolutionary scenarios cannot be ruled out, there are indications that Tango1 underwent horizontal transfer among divergent mosquito species.

  1. Swarming Mechanisms in the Yellow Fever Mosquito: Aggregation Pheromones are Involved in the Mating Behavior of Aedes aegypti

    Science.gov (United States)

    2014-12-01

    Vol. 39, no. 2 Journal of Vector Ecology 347 Swarming mechanisms in the yellow fever mosquito: aggregation pheromones are involved in the mating...Downes 1966, Provost and Haeger 1967), Aedes albopictus (Nijhot and Craig 1971), Culiseta inornata (Kliewer et al. 1966, Lang and Foster 1976), and some...aegypti Linnaeus is one of the most medically important mosquitoes as the main vector of dengue, chikungunya, and yellow fever viruses, in addition to its

  2. The bacterium Wolbachia exploits host innate immunity to establish a symbiotic relationship with the dengue vector mosquito Aedes aegypti

    OpenAIRE

    Pan, Xiaoling; Pike, Andrew; Joshi, Deepak; Bian, Guowu; McFadden, Michael J; Lu, Peng; Liang, Xiao; Zhang, Fengrui; Raikhel, Alexander S; Xi, Zhiyong

    2017-01-01

    A host’s immune system plays a central role in shaping the composition of the microbiota and, in return, resident microbes influence immune responses. Symbiotic associations of the maternally transmitted bacterium Wolbachia occur with a wide range of arthropods. It is, however, absent from the dengue and Zika vector mosquito Aedes aegypti in nature. When Wolbachia is artificially forced to form symbiosis with this new mosquito host, it boosts the basal immune response and enhances the mosquit...

  3. Protection against mosquito vectors Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus using a novel insect repellent, ethyl anthranilate.

    Science.gov (United States)

    Islam, Johirul; Zaman, Kamaruz; Tyagi, Varun; Duarah, Sanjukta; Dhiman, Sunil; Chattopadhyay, Pronobesh

    2017-10-01

    Growing concern on the application of synthetic mosquito repellents in the recent years has instigated the identification and development of better alternatives to control different mosquito-borne diseases. In view of above, present investigation evaluates the repellent activity of ethyl anthranilate (EA), a non-toxic, FDA approved volatile food additive against three known mosquito vectors namely, Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus under laboratory conditions following standard protocols. Three concentration levels (2%, 5% and 10% w/v) of EA were tested against all the three selected mosquito species employing K & D module and arm-in-cage method to determine the effective dose (ED 50 ) and complete protection time (CPT), respectively. The repellent activity of EA was further investigated by modified arm-in-cage method to determine the protection over extended spatial ranges against all mosquito species. All behavioural situations were compared with the well-documented repellent N,N-diethylphenyl acetamide (DEPA) as a positive control. The findings demonstrated that EA exhibited significant repellent activity against all the three mosquitoes species. The ED 50 values of EA, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus were found to be 0.96%, 5.4% and 3.6% w/v, respectively. At the concentration of 10% w/v, it provided CPTs of 60, 60 and 30min, respectively, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes. Again in spatial repellency evaluation, EA was found to be extremely effective in repelling all the three tested species of mosquitoes. Ethyl anthranilate provided comparable results to standard repellent DEPA during the study. Results have concluded that the currently evaluated chemical, EA has potential repellent activity against some well established mosquito vectors. The study emphasizes that repellent activity of EA could be exploited for developing effective, eco

  4. Larvicidal property of green synthesized silver nanoparticles against vector mosquitoes (Anopheles stephensi and Aedes aegypti

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    Rajamani Bhuvaneswari

    2016-10-01

    Full Text Available Mosquito vectors spread severe human diseases which lead to millions of deaths every year. Vector management is ultimately aimed to develop the health of every individual’s life by reducing the mosquito diversity. Control of vectors in growing counties is an important issue with various aspects. The advancement of green nanotechnology will attribute the solution for vector controlling policy. To identify the larvicidal property of silver nanoparticles (AgNPs using Belosynapsis kewensis (B. kewensis leaf extract against the Anopheles stephensi (A. stephensi and Aedes aegypti (A. aegypti in vitro study (LC50 and LC90 was analyzed. The synthesized AgNPs were characterized by UV–vis. (Ultraviolet–visible spectroscopy, FTIR (Fourier Transform Infra Red spectroscopy, TEM (Transmission Electron Microscopy, and XRD (X-ray Diffraction. Green AgNPs have a maximum absorption at 411 nm. The FTIR spectrum showed prominent peaks in (3863.55, 3759.02, 3361.01, 2926.81, 1575.12, 1388.16, 1034.79, 821.96, 717.07, 590.92, 534.32 and 472.42 cm−1 in the region of 4000–400 cm−1. The XRD peaks shown at 27.4°, 35.90°, 37.20°, 51.23° and 71.10° correspond to (311, (100, (101, (104 and (006 planes for face centered cubic (FCC. The TEM image showed the NPs with an average size of 24 ± 1.6 nm. In vitro larvicidal activity of AgNPs was used against the fourth instar of A. stephensi and A. aegypti. The LC50 and LC90 values of AgNPs showed to be effective against A. stephensi (LC50 = 78.4; LC90 = 144.7 ppm followed by A. aegypti (LC50 = 84.2; LC90 = 117.3 ppm. These results recommend that the green synthesized AgNPs have a potential to be used as a candidate for the control of A. stephensi and A. aegypti through eco-friendly and cost effective approach.

  5. Mosquito Infestation and Dengue Virus Infection in Aedes aegypti Females in Schools in Mérida, México

    Science.gov (United States)

    García-Rejón, Julián E.; Loroño-Pino, María Alba; Farfán-Ale, José Arturo; Flores-Flores, Luis F.; López-Uribe, Mildred P.; del Rosario Najera-Vazquez, Maria; Nuñez-Ayala, Guadalupe; Beaty, Barry J.; Eisen, Lars

    2011-01-01

    We determined abundance of Aedes aegypti mosquitoes and presence of dengue virus (DENV) in females collected from schools in Mérida, México, during 2008 and 2009. Backpack aspiration from 24 schools produced 468 females of Ae. aegypti and 1,676 females of another human biter, Culex quinquefasciatus. Ae. aegypti females were collected most commonly from classrooms followed by offices and bathrooms. Of these females, 24.7% were freshly fed. Examination of 118 pools of Ae. aegypti females (total of 415 females) for presence of DENV RNA produced 19 positive pools (16.1%). DENV-infected pools were detected from 11 (45.8%) of 24 schools and came from different room types, including classrooms, offices, and bathrooms. The overall rate of DENV infection per 100 Ae. aegypti females was 4.8. We conclude that schools in Mérida present a risk environment for students, teachers, and other personnel to be exposed to mosquitoes and bites of DENV-infected Ae. aegypti females. PMID:21363990

  6. Growth characteristics of ChimeriVax-DEN2 vaccine virus in Aedes aegypti and Aedes albopictus mosquitoes.

    Science.gov (United States)

    Johnson, Barbara W; Chambers, Trudy V; Crabtree, Mary B; Bhatt, Tejal R; Guirakhoo, Farshad; Monath, Thomas P; Miller, Barry R

    2002-09-01

    The chimeric yellow fever (YF) 17D-dengue type 2 (ChimeriVax-DEN2) vaccine virus developed by Acambis, Inc. (Cambridge, MA) contains the prM and E genes of wild-type (wt) dengue 2 (DEN-2) (strain PUO-218) virus in the YF vaccine virus (strain 17D) backbone. The potential of ChimeriVax-DEN2 virus to infect and be transmitted by Aedes aegypti, the principal DEN and YF virus mosquito vector, and Aedes albopictus, a species that occurs in areas of active transmission of YF and DEN viruses, was evaluated. Mosquitoes were intrathoracically (IT) inoculated with virus or were fed a virus-laden blood meal, and the replication kinetics of ChimeriVax-DEN2 were compared with the wt DEN-2 and YF 17D vaccine viruses. Replication of YF 17D virus is attenuated in cultured Ae. albopictus C6/36 mosquito cells and in Ae. aegypti and Ae. albopictus mosquitoes. Growth of ChimeriVax-DEN2 virus similarly was restricted in C6/36 cells and in mosquitoes. ChimeriVax-DEN2 replicated in 56% of IT inoculated Ae. aegypti, and virus disseminated to head tissue in 36%, with a mean viral titer of 1.8 log10 PFU/mosquito. Of mosquitoes, 16% of Ae. aegypti and 24% of Ae. albopictus were infected 14 days after a blood meal containing ChimeriVax-DEN2, but virus did not disseminate to head tissue. In contrast, DEN-2 replicated in all IT inoculated and orally infected Ae. aegypti (mean titer 5.5 log10 PFU/mosquito), and virus disseminated to head tissue in 95%. Of Ae. albopictus, 84% were infected after a blood meal containing DEN-2 virus; dissemination occurred in 36%. Replication of ChimeriVax-DEN2 virus in mosquitoes corresponded to that of YF 17D vaccine virus, which is restricted in its ability to infect and replicate in mosquitoes. Therefore, transmission of ChimeriVax-DEN2 virus by vector mosquitoes is unlikely.

  7. Extensive Genetic Differentiation between Homomorphic Sex Chromosomes in the Mosquito Vector, Aedes aegypti

    Science.gov (United States)

    Fontaine, Albin; Filipović, Igor; Fansiri, Thanyalak; Hoffmann, Ary A.; Cheng, Changde; Kirkpatrick, Mark

    2017-01-01

    Abstract Mechanisms and evolutionary dynamics of sex-determination systems are of particular interest in insect vectors of human pathogens like mosquitoes because novel control strategies aim to convert pathogen-transmitting females into nonbiting males, or rely on accurate sexing for the release of sterile males. In Aedes aegypti, the main vector of dengue and Zika viruses, sex determination is governed by a dominant male-determining locus, previously thought to reside within a small, nonrecombining, sex-determining region (SDR) of an otherwise homomorphic sex chromosome. Here, we provide evidence that sex chromosomes in Ae. aegypti are genetically differentiated between males and females over a region much larger than the SDR. Our linkage mapping intercrosses failed to detect recombination between X and Y chromosomes over a 123-Mbp region (40% of their physical length) containing the SDR. This region of reduced male recombination overlapped with a smaller 63-Mbp region (20% of the physical length of the sex chromosomes) displaying high male–female genetic differentiation in unrelated wild populations from Brazil and Australia and in a reference laboratory strain originating from Africa. In addition, the sex-differentiated genomic region was associated with a significant excess of male-to-female heterozygosity and contained a small cluster of loci consistent with Y-specific null alleles. We demonstrate that genetic differentiation between sex chromosomes is sufficient to assign individuals to their correct sex with high accuracy. We also show how data on allele frequency differences between sexes can be used to estimate linkage disequilibrium between loci and the sex-determining locus. Our discovery of large-scale genetic differentiation between sex chromosomes in Ae. aegypti lays a new foundation for mapping and population genomic studies, as well as for mosquito control strategies targeting the sex-determination pathway. PMID:28945882

  8. Chemosensory responses to the repellent nepeta essential oil and its major component nepetalactone by the yellow fever mosquito, aedes aegypti, a vector of zika virus

    Science.gov (United States)

    Nepeta essential oil (Neo) (catnip) and its major component, nepetalactone, have long been known to repel insects including mosquitoes. However, the neural mechanisms through which these repellents are detected by mosquitoes, including the yellow fever mosquito Aedes aegypti, an important vector of...

  9. A leucokinin mimic elicits aversive behavior in mosquito Aedes aegypti (L.) and inhibits the sugar taste neuron

    Science.gov (United States)

    Insect kinins (leucokinins) are multifunctional peptides acting as neurohormones and neurotransmitters. In females of the mosquito vector Aedes aegypti (L.), aedeskinins are known to stimulate fluid secretion from the renal organs (Malpighian tubules) and hindgut contractions by activating a G prot...

  10. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow fever mosquito, aedes aegypti

    Science.gov (United States)

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as DEET and other insect repellents. Two other ...

  11. Collective behavior quantification on human odor effects against female Aedes aegypti mosquitoes-Open source development.

    Directory of Open Access Journals (Sweden)

    Abdul Halim Poh

    Full Text Available Classifying and quantifying mosquito activity includes a plethora of categories, ranging from measuring flight speeds, repellency, feeding rates, and specific behaviors such as home entry, swooping and resting, among others. Entomologists have been progressing more toward using machine vision for efficiency for this endeavor. Digital methods have been used to study the behavior of insects in labs, for instance via three-dimensional tracking with specialized cameras to observe the reaction of mosquitoes towards human odor, heat and CO2, although virtually none was reported for several important fields, such as repellency studies which have a significant need for a proper response quantification. However, tracking mosquitoes individually is a challenge and only limited number of specimens can be studied. Although tracking large numbers of individual insects is hailed as one of the characteristics of an ideal automated image-based tracking system especially in 3D, it also is a costly method, often requiring specialized hardware and limited access to the algorithms used for mapping the specimens. The method proposed contributes towards (a unlimited open source use, (b a low-cost setup, (c complete guide for any entomologist to adapt in terms of hardware and software, (d simple to use, and (e a lightweight data output for collective behavior analysis of mosquitoes. The setup is demonstrated by testing a simple response of mosquitoes in the presence of human odor versus control, one session with continuous human presence as a stimuli and the other with periodic presence. A group of female Aedes aegypti (Linnaeus mosquitoes are released into a white-background chamber with a transparent acrylic panel on one side. The video feed of the mosquitoes are processed using filtered contours in a threshold-adjustable video. The mosquitoes in the chamber are mapped on the raster where the coordinates of each mosquito are recorded with the corresponding timestamp

  12. Present Day and Future Population Dynamics of the Dengue Vector Mosquito Aedes aegypti Using a Water Container Energy Balance Model

    Science.gov (United States)

    Steinhoff, D.

    2017-12-01

    Dengue infections are estimated to total nearly 400 million per year worldwide, with both the geographic range and the magnitude of infections having increased in the past 50 years. The primary dengue vector mosquito Aedes aegypti is closely associated with humans. It lives exclusively in urban and semi-urban areas, preferentially bites humans, and spends its developmental stages in artificial water containers. Climate regulates the development of Ae. aegypti immature mosquitoes in artificial containers. Potential containers for Ae. aegypti immature development include, but are not limited to, small sundry items (e.g., bottles, cans, plastic containers), buckets, tires, barrels, tanks, and cisterns. Successful development of immature mosquitoes from eggs to larvae, pupae, and adults is largely dependent on the availability of water and the thermal properties of the water in the containers. An energy balance container model termed the Water Height And Temperature in Container Habitats Energy Model (WHATCH'EM) solves for water temperature and height for user-specified containers with readily available meteorological data. Output from WHATCH'EM is used to estimate development parameters for the immature life stages of the Ae. aegypti mosquito, allowing for assessment of habitat suitability across varying natural environments. Variability amongst different artificial containers (e.g., size, color, material, shape), shading scenarios, and water availability scenarios is also addressed. WHATCH'EM is also coupled with an Ae. aegypti life cycle model to include the effects of the aforementioned factors on survival. Projections of future climate scenarios that take into account changes not only in temperature but also precipitation, humidity, and radiative effects are used in WHATCH'EM to estimate how Ae. aegypti population dynamics may change.

  13. The fat body transcriptomes of the yellow fever mosquito Aedes aegypti, pre- and post- blood meal.

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    David P Price

    Full Text Available The fat body is the main organ of intermediary metabolism in insects and the principal source of hemolymph proteins. As part of our ongoing efforts to understand mosquito fat body physiology and to identify novel targets for insect control, we have conducted a transcriptome analysis of the fat body of Aedes aegypti before and in response to blood feeding.We created two fat body non-normalized EST libraries, one from mosquito fat bodies non-blood fed (NBF and another from mosquitoes 24 hrs post-blood meal (PBM. 454 pyrosequencing of the non-normalized libraries resulted in 204,578 useable reads from the NBF sample and 323,474 useable reads from the PBM sample. Alignment of reads to the existing reference Ae. aegypti transcript libraries for analysis of differential expression between NBF and PBM samples revealed 116,912 and 115,051 matches, respectively. De novo assembly of the reads from the NBF sample resulted in 15,456 contigs, and assembly of the reads from the PBM sample resulted in 15,010 contigs. Collectively, 123 novel transcripts were identified within these contigs. Prominently expressed transcripts in the NBF fat body library were represented by transcripts encoding ribosomal proteins. Thirty-five point four percent of all reads in the PBM library were represented by transcripts that encode yolk proteins. The most highly expressed were transcripts encoding members of the cathepsin b, vitellogenin, vitellogenic carboxypeptidase, and vitelline membrane protein families.The two fat body transcriptomes were considerably different from each other in terms of transcript expression in terms of abundances of transcripts and genes expressed. They reflect the physiological shift of the pre-feeding fat body from a resting state to vitellogenic gene expression after feeding.

  14. The Identification of Suberosin from Prangos pabularia Essential Oil and Its Mosquito Activity against Aedes aegypti

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    Nurhayat Tabanca

    2016-05-01

    Full Text Available A detailed analysis of Prangos pabularia Lindl. (Apiaceae fruit oil was performed by gas chromatography (GC-FID and gas chromatography-mass spectrometry (GC-MS. Bicyclogermacrene (21%, (Z- b -ocimene (19%, a -humulene (8%, a -pinene (8% and spathulenol (6% were the main constituents of the oil. One compound with 1.8% at RI 3420 remained unidentified or tentatively identified as suberosin from the Wiley GC-MS Library. T he assumed compound, suberosin was synthesized in two steps and its structure was confirmed by 1D NMR and GC- MS analyses. As part of our continued research to discover new chemicals for use in mosquito control agents as repellents and larvicides, suberosin and its parent compound coumarin were investigated for the mosquito biting deterrent and larvicidal activity against Aedes aegypti. Both suberosin and coumarin showed biting deterrent activity but the activity was lower than the positive control, DEET (N,N-diethyl-3-methylbenzamide. In larval bioassays, suberosin with LC 50 value of 8.1 ppm was significantly more toxic than c oumarin (LC 50 = 49.6 ppm at 24-h post treatment. These results indicate that suberosin may be useful for use as mosquito larvicidal agent .

  15. Blocking of Plasmodium transmission by cooperative action of Cecropin A and Defensin A in transgenic Aedes aegypti mosquitoes.

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    Kokoza, Vladimir; Ahmed, Abdouelaziz; Woon Shin, Sang; Okafor, Nwando; Zou, Zhen; Raikhel, Alexander S

    2010-05-04

    To overcome burden of mosquito-borne diseases, multiple control strategies are needed. Population replacement with genetically modified mosquitoes carrying antipathogen effector genes is one of the possible approaches for controlling disease transmission. However, transgenic mosquitoes with antipathogen phenotypes based on overexpression of a single type effector molecule are not efficient in interrupting pathogen transmission. Here, we show that co-overexpression of two antimicrobial peptides (AMP), Cecropin A, and Defensin A, in transgenic Aedes aegypti mosquitoes results in the cooperative antibacterial and antiPlasmodium action of these AMPs. The transgenic hybrid mosquitoes that overexpressed both Cecropin A and Defensin A under the control of the vitellogenin promoter exhibited an elevated resistance to Pseudomonas aeruginosa infection, indicating that these AMPs acted cooperatively against this pathogenic bacterium. In these mosquitoes infected with P. gallinaceum, the number of oocysts was dramatically reduced in midguts, and no sporozoites were found in their salivary glands when the mosquitoes were fed twice to reactivate transgenic AMP production. Infection experiments using the transgenic hybrid mosquitoes, followed by sequential feeding on naive chicken, and then naive wild-type mosquitoes showed that the Plasmodium transmission was completely blocked. This study suggests an approach in generating transgenic mosquitoes with antiPlasmodium refractory phenotype, which is coexpression of two or more effector molecules with cooperative action on the parasite.

  16. Mosquito-Producing Containers, Spatial Distribution, and Relationship between Aedes aegypti Population Indices on the Southern Boundary of its Distribution in South America (Salto, Uruguay)

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    Basso, César; Caffera, Ruben M.; García da Rosa, Elsa; Lairihoy, Rosario; González, Cristina; Norbis, Walter; Roche, Ingrid

    2012-01-01

    A study was conducted in the city of Salto, Uruguay, to identify mosquito-producing containers, the spatial distribution of mosquitoes and the relationship between the different population indices of Aedes aegypti. On each of 312 premises visited, water-filled containers and immature Ae. aegypti mosquitoes were identified. The containers were counted and classified into six categories. Pupae per person and Stegomyia indices were calculated. Pupae per person were represented spatially. The number of each type of container and number of mosquitoes in each were analyzed and compared, and their spatial distribution was analyzed. No significant differences in the number of the different types of containers with mosquitoes or in the number of mosquitoes in each were found. The distribution of the containers with mosquito was random and the distribution of mosquitoes by type of container was aggregated or highly aggregated. PMID:23128295

  17. Mosquito-producing containers, spatial distribution, and relationship between Aedes aegypti population indices on the southern boundary of its distribution in South America (Salto, Uruguay).

    Science.gov (United States)

    Basso, César; Caffera, Ruben M; García da Rosa, Elsa; Lairihoy, Rosario; González, Cristina; Norbis, Walter; Roche, Ingrid

    2012-12-01

    A study was conducted in the city of Salto, Uruguay, to identify mosquito-producing containers, the spatial distribution of mosquitoes and the relationship between the different population indices of Aedes aegypti. On each of 312 premises visited, water-filled containers and immature Ae. aegypti mosquitoes were identified. The containers were counted and classified into six categories. Pupae per person and Stegomyia indices were calculated. Pupae per person were represented spatially. The number of each type of container and number of mosquitoes in each were analyzed and compared, and their spatial distribution was analyzed. No significant differences in the number of the different types of containers with mosquitoes or in the number of mosquitoes in each were found. The distribution of the containers with mosquito was random and the distribution of mosquitoes by type of container was aggregated or highly aggregated.

  18. Wolbachia infection in Aedes aegypti mosquitoes alters blood meal excretion and delays oviposition without affecting trypsin activity.

    Science.gov (United States)

    Pimenta de Oliveira, Sofia; Dantas de Oliveira, Caroline; Viana Sant'Anna, Mauricio Roberto; Carneiro Dutra, Heverton Leandro; Caragata, Eric Pearce; Moreira, Luciano Andrade

    2017-08-01

    Blood feeding in Aedes aegypti is essential for reproduction, but also permits the mosquito to act as a vector for key human pathogens such as the Zika and dengue viruses. Wolbachia pipientis is an endosymbiotic bacterium that can manipulate the biology of Aedes aegypti mosquitoes, making them less competent hosts for many pathogens. Yet while Wolbachia affects other aspects of host physiology, it is unclear whether it influences physiological processes associated with blood meal digestion. To that end, we examined the effects of wMel Wolbachia infection in Ae. aegypti, on survival post-blood feeding, blood meal excretion, rate of oviposition, expression levels of key genes involved in oogenesis, and activity levels of trypsin blood digestion enzymes. We observed that wMel infection altered the rate and duration of blood meal excretion, delayed the onset of oviposition and was associated with a greater number of eggs being laid later. wMel-infected Ae. aegypti also had lower levels of key yolk protein precursor genes necessary for oogenesis. However, all of these effects occurred without a change in trypsin activity. These results suggest that Wolbachia infection may disrupt normal metabolic processes associated with blood feeding and reproduction in Ae. aegypti. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The role of male harassment on female fitness for the dengue vector mosquitoAedes aegypti.

    Science.gov (United States)

    Helinski, Michelle E H; Harrington, Laura C

    2012-08-01

    Sexual harassment studies in insects suggest that females can incur several kinds of costs from male harassment and mating. Here, we examined direct and indirect costs of male harassment on components of female fitness in the predominantly monandrous mosquito Aedes aegypti . To disentangle the costs of harassment versus the costs of mating, we held females at a low or high density with males whose claspers were modified to prevent insemination, and compared these to females held with normal males and to those held with females or alone. A reduced longevity was observed when females were held under high density conditions with males or females, regardless if male claspers had been modified. There was no consistent effect of harassment on female fecundity. Net reproductive rate (R 0 ) was higher in females held at low density with normal males compared to females held with males in the other treatments, even though only a small number of females showed direct evidence of remating. Indirect costs and benefits that were not due to harassment alone were observed. Daughters of females held with normal males at high density had reduced longevity compared to daughters from females held without conspecifics. However, their fitness (R 0 ) was higher compared to females in all other treatments. Overall, our results indicate that A. aegypti females do not suffer a fitness cost from harassment of males when kept at moderate densities, and they suggest the potential for benefits obtained from ejaculate components.

  20. Identification of Candidate Iron Transporters From the ZIP/ZnT Gene Families in the Mosquito Aedes aegypti

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    Hitoshi Tsujimoto

    2018-04-01

    Full Text Available Mosquito-transmitted viral pathogens, such as dengue and Zika, afflict tens of thousands of people every year. These viruses are transmitted during the blood-feeding process that is required for mosquito reproduction, the most important vector being Aedes aegypti. While vertebrate blood is rich in protein, its high iron content is potentially toxic to mosquitoes. Although iron transport and sequestration are essential in the reproduction of vector mosquitoes, we discovered that culicine mosquitoes lack homologs of the common iron transporter NRAMP. Using a novel cell-based screen, we identified two ZIP and one ZnT genes as candidate iron transporters in the mosquito A. aegypti, the vector of dengue, Zika, and chikungunya. We determined the organ-specific expression pattern of these genes at critical time points in early reproduction. The result indicates modulation of these genes upon blood feeding, especially a ZIP13 homolog that is highly up-regulated after blood feeding, suggesting its importance in iron mobilization during blood digestion and reproduction. Gene silencing resulted in differential iron accumulation in the midgut and ovaries. This study sets a foundation for further investigation of iron transport and control strategies of this viral vector.

  1. Antiviral Hammerhead Ribozymes Are Effective for Developing Transgenic Suppression of Chikungunya Virus in Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Mishra, Priya; Furey, Colleen; Balaraman, Velmurugan; Fraser, Malcolm J

    2016-06-10

    The chikungunya virus (CHIKV) is an emerging pathogen with widespread distribution in regions of Africa, India, and Asia that threatens to spread into temperate climates with the introduction of its major vector, Aedes albopictus. CHIKV causes a disease frequently misdiagnosed as dengue fever, with potentially life-threatening symptoms that can result in a longer-term debilitating arthritis. The increasing risk of spread from endemic regions via human travel and commerce and the current absence of a vaccine put a significant proportion of the world population at risk for this disease. In this study we designed and tested hammerhead ribozymes (hRzs) targeting CHIKV structural protein genes of the RNA genome as potential antivirals both at the cellular and in vivo level. We employed the CHIKV strain 181/25, which exhibits similar infectivity rates in both Vero cell cultures and mosquitoes. Virus suppression assay performed on transformed Vero cell clones of all seven hRzs demonstrated that all are effective at inhibiting CHIKV in Vero cells, with hRz #9 and #14 being the most effective. piggyBac transformation vectors were constructed using the Ae. aegypti t-RNA(val) Pol III promoted hRz #9 and #14 effector genes to establish a total of nine unique transgenic Higgs White Eye (HWE) Ae. aegypti lines. Following confirmation of transgene expression by real-time polymerase chain reaction (RT-PCR), comparative TCID50-IFA analysis, in situ Immuno-fluorescent Assays (IFA) and analysis of salivary CHIKV titers demonstrated effective suppression of virus replication at 7 dpi in heterozygous females of each of these transgenic lines compared with control HWE mosquitoes. This report provides a proof that appropriately engineered hRzs are powerful antiviral effector genes suitable for population replacement strategies.

  2. Antiviral Hammerhead Ribozymes Are Effective for Developing Transgenic Suppression of Chikungunya Virus in Aedes aegypti Mosquitoes

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    Priya Mishra

    2016-06-01

    Full Text Available The chikungunya virus (CHIKV is an emerging pathogen with widespread distribution in regions of Africa, India, and Asia that threatens to spread into temperate climates with the introduction of its major vector, Aedes albopictus. CHIKV causes a disease frequently misdiagnosed as dengue fever, with potentially life-threatening symptoms that can result in a longer-term debilitating arthritis. The increasing risk of spread from endemic regions via human travel and commerce and the current absence of a vaccine put a significant proportion of the world population at risk for this disease. In this study we designed and tested hammerhead ribozymes (hRzs targeting CHIKV structural protein genes of the RNA genome as potential antivirals both at the cellular and in vivo level. We employed the CHIKV strain 181/25, which exhibits similar infectivity rates in both Vero cell cultures and mosquitoes. Virus suppression assay performed on transformed Vero cell clones of all seven hRzs demonstrated that all are effective at inhibiting CHIKV in Vero cells, with hRz #9 and #14 being the most effective. piggyBac transformation vectors were constructed using the Ae. aegypti t-RNAval Pol III promoted hRz #9 and #14 effector genes to establish a total of nine unique transgenic Higgs White Eye (HWE Ae. aegypti lines. Following confirmation of transgene expression by real-time polymerase chain reaction (RT-PCR, comparative TCID50-IFA analysis, in situ Immuno-fluorescent Assays (IFA and analysis of salivary CHIKV titers demonstrated effective suppression of virus replication at 7 dpi in heterozygous females of each of these transgenic lines compared with control HWE mosquitoes. This report provides a proof that appropriately engineered hRzs are powerful antiviral effector genes suitable for population replacement strategies

  3. First report on invasion of yellow fever mosquito, Aedes aegypti, at Narita International Airport, Japan in August 2012.

    Science.gov (United States)

    Sukehiro, Nayu; Kida, Nori; Umezawa, Masahiro; Murakami, Takayuki; Arai, Naoko; Jinnai, Tsunesada; Inagaki, Shunichi; Tsuchiya, Hidetoshi; Maruyama, Hiroshi; Tsuda, Yoshio

    2013-01-01

    The invasion of the yellow fever mosquito Aedes aegypti at Narita International Airport, Japan was detected for the first time. During the course of routine vector surveillance at Narita International Airport, 27 Ae. aegypti adults emerged from larvae and pupae collected from a single larvitrap placed near No. 88 spot at passenger terminal 2 on August 8, 2012. After the appearance of Ae. aegypti in the larvitrap, we defined a 400-m buffer zone and started an intensive vector survey using an additional 34 larvitraps and 15 CO2 traps. International aircraft and passenger terminal 2 were also inspected, and one Ae. aegypti male was collected from the cargo space of an international aircraft from Darwin via Manila on August 28, 2012. Larvicide treatment with 1.5% fenitrothion was conducted in 64 catch basins and one ditch in the 400-m buffer zone. Twenty-four large water tanks were also treated at least once with 0.5% pyriproxyfen, an insect growth regulator. No Ae. aegypti eggs or adults were found during the 1-month intensive vector survey after finding larvae and pupae in the larvitrap. We concluded that Ae. aegypti had failed to establish a population at Narita International Airport.

  4. Genetic structure and phylogeography of Aedes aegypti, the dengue and yellow-fever mosquito vector in Bolivia.

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    Paupy, Christophe; Le Goff, Gilbert; Brengues, Cécile; Guerra, Mabel; Revollo, Jimmy; Barja Simon, Zaïra; Hervé, Jean-Pierre; Fontenille, Didier

    2012-08-01

    Between the 16th and 18th centuries, Aedes aegypti (Diptera: Culicidae), a mosquito native to Africa, invaded the Americas, where it was successively responsible for the emergence of yellow fever (YF) and dengue (DEN). The species was eradicated from numerous American countries in the mid-20th century, but re-invaded them in the 1970s and 1980s. Little is known about the precise identities of Ae. aegypti populations which successively thrived in South America, or their relation with the epidemiological changes in patterns of YF and DEN. We examined these questions in Bolivia, where Ae. aegypti, eradicated in 1943, re-appeared in the 1980s. We assessed the genetic variability and population genetics of Ae. aegypti samples in order to deduce their genetic structure and likely geographic origin. Using a 21-population set covering Bolivia, we analyzed the polymorphism at nine microsatellite loci and in two mitochondrial DNA regions (COI and ND4). Microsatellite markers revealed a significant genetic structure among geographic populations (F(ST)=0.0627, PBolivia. Analysis of mtDNA sequences revealed the existence of two genetic lineages, one dominant lineage recovered throughout Bolivia, and the second restricted to rural localities in South Bolivia. Phylogenic analysis indicated that this minority lineage was related to West African Ae. aegypti specimens. In conclusion, our results suggested a temporal succession of Ae. aegypti populations in Bolivia, that potentially impacted the epidemiology of dengue and yellow fever. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Assessment of Local Mosquito Species Incriminates Aedes aegypti as the Potential Vector of Zika Virus in Australia.

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    Sonja Hall-Mendelin

    2016-09-01

    Full Text Available Within the last 10 years Zika virus (ZIKV has caused unprecedented epidemics of human disease in the nations and territories of the western Pacific and South America, and continues to escalate in both endemic and non-endemic regions. We evaluated the vector competence of Australian mosquitoes for ZIKV to assess their potential role in virus transmission.Mosquitoes were exposed to infectious blood meals containing the prototype African ZIKV strain. After 14 days incubation at 28°C and high relative humidity, infection, dissemination and transmission rates were assessed. Infection in Culex annulirostris and Cx. sitiens could not be detected. 8% of Cx. quinquefasciatus were infected, but the virus did not disseminate in this species. Despite having infection rates > 50%, Aedes notoscriptus and Ae. vigilax did not transmit ZIKV. In contrast, Ae. aegypti had infection and transmission rates of 57% and 27%, respectively. In susceptibility trials, the virus dose required to infect 50% (ID50 of Ae. aegypti was106.4 tissue culture infectious dose50 (TCID50/mL. Additionally, a threshold viral load within the mosquito of at least 105.1 TCID50 equivalents/mL had to be reached before virus transmission occurred.We confirmed Ae. aegypti to be the most likely mosquito vector of ZIKV in Australia, although the restricted distribution of this species will limit the receptive zone to northern Queensland where this species occurs. Importantly, the role in ZIKV transmission of Culex and other Aedes spp. tested will be negligible. Despite being the implicated vector, the relatively high ID50 and need for a high titer disseminated infection in Ae. aegypti suggest that high mosquito population densities will be required to facilitate epidemic ZIKV transmission among the currently immunologically naïve human population in Australia.

  6. Competitive advantage of a dengue 4 virus when co-infecting the mosquito Aedes aegypti with a dengue 1 virus.

    Science.gov (United States)

    Vazeille, Marie; Gaborit, Pascal; Mousson, Laurence; Girod, Romain; Failloux, Anna-Bella

    2016-07-08

    Dengue viruses (DENV) are comprised in four related serotypes (DENV-1 to 4) and are critically important arboviral pathogens affecting human populations in the tropics. South American countries have seen the reemergence of DENV since the 1970's associated with the progressive re-infestation by the mosquito vector, Aedes aegypti. In French Guiana, DENV is now endemic with the co-circulation of different serotypes resulting in viral epidemics. Between 2009 and 2010, a predominant serotype change occurred from DENV-1 to DENV-4 suggesting a competitive displacement. The aim of the present study was to evaluate the potential role of the mosquito in the selection of the new epidemic serotype. To test this hypothesis of competitive displacement of one serotype by another in the mosquito vector, we performed mono- and co-infections of local Ae. aegypti collected during the inter-epidemic period with both viral autochthonous epidemic serotypes and compared infection, dissemination and transmission rates. We performed oral artificial infections of F1 populations in BSL-3 conditions and analyzed infection, dissemination and transmission rates. When two populations of Ae. aegypti from French Guiana were infected with either serotype, no significant differences in dissemination and transmission were observed between DENV-1 and DENV-4. However, in co-infection experiments, a strong competitive advantage for DENV-4 was seen at the midgut level leading to a much higher dissemination of this serotype. Furthermore only DENV-4 was present in Ae. aegypti saliva and therefore able to be transmitted. In an endemic context, mosquito vectors may be infected by several DENV serotypes. Our results suggest a possible competition between serotypes at the midgut level in co-infected mosquitoes leading to a drastically different transmission potential and, in this case, favoring the competitive displacement of DENV-1 by DENV-4. This phenomenon was observed despite a similar replicative fitness

  7. The first detected airline introductions of yellow fever mosquitoes (Aedes aegypti) to Europe, at Schiphol International airport, the Netherlands.

    Science.gov (United States)

    Ibañez-Justicia, A; Gloria-Soria, A; den Hartog, W; Dik, M; Jacobs, F; Stroo, A

    2017-12-08

    Air-borne introduction of exotic mosquitoes to Schiphol airport in the Netherlands has been considered plausible based upon findings of mosquitoes in aircraft cabins during 2008, 2010 and 2011. Beginning in 2013, surveillance efforts at Schiphol had focused on promptly detecting accidental introductions at the airport facilities in order to quickly react and avoid temporary proliferation or establishment of mosquito populations, identify the origin of the introductions, and avoid potential transmission of vector-borne diseases. BG-Mosquitaire mosquito traps were set at the most likely locations for arrival of the invasive Aedes mosquitoes as part of the mosquito monitoring program at Schiphol airport. Samples were collected bi-weekly. Upon detection of exotic specimens, information about the origin of the flights arriving to the particular location at the airport where specimens were captured was requested from airport authorities. The GIS tool Intersect was then used to identify airports of origin common to positive trapping locations during the specific trapping period. Captured Aedes aegypti mosquitoes were subsequently genotyped at 12 highly polymorphic microsatellite markers and compared to a reference database of 79 populations around the world to further narrow down their location of origin. In 2016, six adult yellow fever mosquitoes were captured indoors and outdoors at the airport of Schiphol in the Netherlands confirming, for the first time, air-borne transport of this mosquito vector species into Europe. Mosquitoes were captured during three time periods: June, September and October. Containers carried by aircrafts are considered the most likely pathway for this introduction. GIS analysis and genetic assignment tests on these mosquitoes point to North America or the Middle East as possible origins, but the small sample size prevents us from reliably identifying the geographic origin of this introduction. The arrival of Ae. aegypti mosquitoes to Schiphol

  8. Study of Herbal Topical Repellent Made of Betel Leaves (Piper Betle) and Patchouli Oil (Pogostemon Cablin) Mixture Against Yellow Fever Mosquito (Aedes Aegypti)

    OpenAIRE

    Widawati, Mutiara; Riandi, M. Umar

    2015-01-01

    Introduction: Exploration of plants as natural repellants to avoid Aedes aegypti mosquitoes that transmit dengue virus to human is worthy. Betel vine leaves (Piper betle L.) could be used as the material of repellant.The study is aimed to test the repellency,potency, and the safety of Piper betel and patchoulli oil modified gel against Aedes aegypti mosquitoes.Methods: This study is an experimental study and used nulliparous (3-5 days old) female Aedes aegypti. Before the study, safety test w...

  9. Aedes aegypti (Diptera: Culicidae) in Mauritania: First Report on the Presence of the Arbovirus Mosquito Vector in Nouakchott.

    Science.gov (United States)

    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

    2015-07-01

    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: journals.permissions@oup.com.

  10. Mosquito larvicidal efficay of Acorus calamus extracts against Aedes aegypti L. larvae

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    Hashmat Imam

    2014-02-01

    Full Text Available Objective: To evaluate the larvicidal activity of petroleum ether and ethyl alcohol extracts of Acorus calamus (A. calamus. Methods: Petroleum ether and ethyl alcohol extracts were extracted from plant materials through soxhlet extraction process and its efficacy was determined through bioassay method. Extracts were evaluated further for the determination of their LC 50 and LC90 values. Observation of mortality response was assessed after 24 h. Results: Petroleum ether and ethyl alcohol extracts of A. calamus produced 99% and 96% mortality at 125 mg/L respectively. Petroleum ether extract exhibited LC50 at 57.32 mg/L, LC90 at 120.13 mg/L, while ethyl alcohol extract exhibited LC50 at 64.22 mg/L, LC90 at 130.37 mg/L. Conclusions: Present study indicated that A. calamus carries huge potential as a mosquito larvicide. This potential could be exploited for the development of safer and effective botanical mosquito larvicidal tool for the management of Aedes aegypti.

  11. Characterization of Carbonic Anhydrase 9 in the Alimentary Canal of Aedes aegypti and Its Relationship to Homologous Mosquito Carbonic Anhydrases

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    Daniel P. Dixon

    2017-02-01

    Full Text Available In the mosquito midgut, luminal pH regulation and cellular ion transport processes are important for the digestion of food and maintenance of cellular homeostasis. pH regulation in the mosquito gut is affected by the vectorial movement of the principal ions including bicarbonate/carbonate and protons. As in all metazoans, mosquitoes employ the product of aerobic metabolism carbon dioxide in its bicarbonate/carbonate form as one of the major buffers of cellular and extracellular pH. The conversion of metabolic carbon dioxide to bicarbonate/carbonate is accomplished by a family of enzymes encoded by the carbonic anhydrase gene family. This study characterizes Aedes aegypti carbonic anhydrases using bioinformatic, molecular, and immunohistochemical methods. Our analyses show that there are fourteen Aedes aegypti carbonic anhydrase genes, two of which are expressed as splice variants. The carbonic anhydrases were classified as either integral membrane, peripheral membrane, mitochondrial, secreted, or soluble cytoplasmic proteins. Using polymerase chain reaction and Western blotting, one of the carbonic anhydrases, Aedes aegypti carbonic anhydrase 9, was analyzed and found in each life stage, male/female pupae, male/female adults, and in the female posterior midgut. Next, carbonic anhydrase 9 was analyzed in larvae and adults using confocal microscopy and was detected in the midgut regions. According to our analyses, carbonic anhydrase 9 is a soluble cytoplasmic enzyme found in the alimentary canal of larvae and adults and is expressed throughout the life cycle of the mosquito. Based on previous physiological analyses of adults and larvae, it appears AeCA9 is one of the major carbonic anhydrases involved in producing bicarbonate/carbonate which is involved in pH regulation and ion transport processes in the alimentary canal. Detailed understanding of the molecular bases of ion homeostasis in mosquitoes will provide targets for novel mosquito control

  12. Characterization of Carbonic Anhydrase 9 in the Alimentary Canal of Aedes aegypti and Its Relationship to Homologous Mosquito Carbonic Anhydrases.

    Science.gov (United States)

    Dixon, Daniel P; Van Ekeris, Leslie; Linser, Paul J

    2017-02-21

    In the mosquito midgut, luminal pH regulation and cellular ion transport processes are important for the digestion of food and maintenance of cellular homeostasis. pH regulation in the mosquito gut is affected by the vectorial movement of the principal ions including bicarbonate/carbonate and protons. As in all metazoans, mosquitoes employ the product of aerobic metabolism carbon dioxide in its bicarbonate/carbonate form as one of the major buffers of cellular and extracellular pH. The conversion of metabolic carbon dioxide to bicarbonate/carbonate is accomplished by a family of enzymes encoded by the carbonic anhydrase gene family. This study characterizes Aedes aegypti carbonic anhydrases using bioinformatic, molecular, and immunohistochemical methods. Our analyses show that there are fourteen Aedes aegypti carbonic anhydrase genes, two of which are expressed as splice variants. The carbonic anhydrases were classified as either integral membrane, peripheral membrane, mitochondrial, secreted, or soluble cytoplasmic proteins. Using polymerase chain reaction and Western blotting, one of the carbonic anhydrases, Aedes aegypti carbonic anhydrase 9, was analyzed and found in each life stage, male/female pupae, male/female adults, and in the female posterior midgut. Next, carbonic anhydrase 9 was analyzed in larvae and adults using confocal microscopy and was detected in the midgut regions. According to our analyses, carbonic anhydrase 9 is a soluble cytoplasmic enzyme found in the alimentary canal of larvae and adults and is expressed throughout the life cycle of the mosquito. Based on previous physiological analyses of adults and larvae, it appears AeCA9 is one of the major carbonic anhydrases involved in producing bicarbonate/carbonate which is involved in pH regulation and ion transport processes in the alimentary canal. Detailed understanding of the molecular bases of ion homeostasis in mosquitoes will provide targets for novel mosquito control strategies into the

  13. siRNA-Mediated Silencing of doublesex during Female Development of the Dengue Vector Mosquito Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Keshava Mysore

    2015-11-01

    Full Text Available The development of sex-specific traits, including the female-specific ability to bite humans and vector disease, is critical for vector mosquito reproduction and pathogen transmission. Doublesex (Dsx, a terminal transcription factor in the sex determination pathway, is known to regulate sex-specific gene expression during development of the dengue fever vector mosquito Aedes aegypti. Here, the effects of developmental siRNA-mediated dsx silencing were assessed in adult females. Targeting of dsx during A. aegypti development resulted in decreased female wing size, a correlate for body size, which is typically larger in females. siRNA-mediated targeting of dsx also resulted in decreased length of the adult female proboscis. Although dsx silencing did not impact female membrane blood feeding or mating behavior in the laboratory, decreased fecundity and fertility correlated with decreased ovary length, ovariole length, and ovariole number in dsx knockdown females. Dsx silencing also resulted in disruption of olfactory system development, as evidenced by reduced length of the female antenna and maxillary palp and the sensilla present on these structures, as well as disrupted odorant receptor expression. Female lifespan, a critical component of the ability of A. aegypti to transmit pathogens, was also significantly reduced in adult females following developmental targeting of dsx. The results of this investigation demonstrate that silencing of dsx during A. aegypti development disrupts multiple sex-specific morphological, physiological, and behavioral traits of adult females, a number of which are directly or indirectly linked to mosquito reproduction and pathogen transmission. Moreover, the olfactory phenotypes observed connect Dsx to development of the olfactory system, suggesting that A. aegypti will be an excellent system in which to further assess the developmental genetics of sex-specific chemosensation.

  14. Investigating the Potential Range Expansion of the Vector Mosquito Aedes Aegypti in Mexico with NASA Earth Science Remote Sensing Results

    Science.gov (United States)

    Crosson, W. L.; Estes, M. G.; Estes, S. M.; Hayden, M.; Monaghan, A. J.; Eisen, L.; Lozano-Fuentes, S.; Ochoa, C.; Tapia, B.; Welsh-Rodriquez, C. M.; a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20130001856'); toggleEditAbsImage('author_20130001856_show'); toggleEditAbsImage('author_20130001856_hide'); "> hide

    2012-01-01

    In tropical and sub ]tropical regions, the mosquito Aedes aegypti is the major vector for the virus causing dengue, a serious public health issue in these areas. Through ongoing NSF- and NASA-funded studies, field surveys of Aedes aegypti and an integrated modeling approach are being used to improve our understanding of the potential range of the mosquito to expand toward heavily populated high elevation areas such as Mexico City under various climate change and socio ]economic scenarios. This work serves three primary objectives: (1) Employ NASA remotely-sensed data to supplement the environmental monitoring and modeling component of the project. These data-- for example, surface temperature, precipitation, vegetation indices, soil moisture and elevation-- are critical for understanding the habitat necessary for mosquito survival and abundance; (2) Implement training sessions to instruct scientists and students from Mexico and the U.S. on how to use remote sensing and implement the NASA SERVIR Regional Visualization and Monitoring System; (3) Employ the SERVIR framework to optimize the dissemination of key project results in order to increase their societal relevance and benefits in developing climate adaptation strategies. Field surveys of larval, pupal and adult Aedes aegypti, as well as detailed physical and social household characteristics, were conducted in the summers of 2011and 2012 at geographic scales from the household to the community along a transect from sea level to 2400 m ASL. These data are being used in models to estimate Aedes aegypti habitat suitability. In 2011, Aedes aegypti were identified at an elevation of over 2150 m in Puebla, the highest elevation at which this species has been observed.

  15. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow-fever mosquito, Aedes aegypti

    Science.gov (United States)

    Sanford, Jillian L.; Shields, Vonnie D. C.; Dickens, Joseph C.

    2013-03-01

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow-fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as N, N-diethyl-3-methylbenzamide and other insect repellents. Two other neurons with differing spikes responded to salt (NaCl) and sucrose. This is the first report of a gustatory receptor neuron specific for insect repellents in mosquitoes and may provide a tool for screening chemicals to discover novel or improved feeding deterrents and repellents for use in the management of arthropod disease vectors.

  16. RNA-seq analyses of blood-induced changes in gene expression in the mosquito vector species, Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Olson Ken E

    2011-01-01

    Full Text Available Abstract Background Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito Aedes aegypti (Diptera, Culicidae, a vector of Dengue viruses, Yellow Fever Virus (YFV and Chikungunya virus (CV, is the subject of this study to look at genome-wide changes in gene expression following a blood meal. Results Transcriptional changes that follow a blood meal in Ae. aegypti females were explored using RNA-seq technology. Over 30% of more than 18,000 investigated transcripts accumulate differentially in mosquitoes at five hours after a blood meal when compared to those fed only on sugar. Forty transcripts accumulate only in blood-fed mosquitoes. The list of regulated transcripts correlates with an enhancement of digestive activity and a suppression of environmental stimuli perception and innate immunity. The alignment of more than 65 million high-quality short reads to the Ae. aegypti reference genome permitted the refinement of the current annotation of transcript boundaries, as well as the discovery of novel transcripts, exons and splicing variants. Cis-regulatory elements (CRE and cis-regulatory modules (CRM enriched significantly at the 5'end flanking sequences of blood meal-regulated genes were identified. Conclusions This study provides the first global view of the changes in transcript accumulation elicited by a blood meal in Ae. aegypti females. This information permitted the identification of classes of potentially co-regulated genes and a description of biochemical and physiological events that occur immediately after blood feeding. The data presented here serve as a basis for novel vector control and pathogen transmission

  17. Ecdysis period and rate deviations of dengue mosquito vector, Aedes aegypti reared in different artificial water-holding containers.

    Science.gov (United States)

    Almanzor, Beatriz Louise J; Ho, Howell T; Carvajal, Thaddeus M

    2016-03-01

    Artificial water-holding containers (AWHCs) have been well-documented in many Aedes aegypti studies for dengue surveillance and developmental research. Hence, we investigated the role of different AHWCs on the development and ecdysis period of Ae. aegypti dengue vector, a container breeding mosquito. Nine types of AWHCs, namely glass, polystyrene foam, rubber, steel, porcelain, plastic, aluminum, clay and concrete, were chosen for the study. All AWHCs were subjected to the developmental assay for an observation period of 10 days. Regression and hazard analyses were employed to the developmental stages and the characteristics of the AWHCs. The observations revealed that Ae. aegypti development is fastest in glass and polystyrene containers while slowest in concrete containers. Moreover, pupal ecdysis appears to be the most affected by the characteristics of the AWHCs based on regression and hazard analyses. Characteristics of the container that can regulate water temperature seem to be the driving force with regards to the slow or fast development of Ae. aegypti, more notably in pupal ecdysis. The results of the study further strengthen our understanding on the dynamics of Ae. aegypti's developmental biology to different characteristics of artificial water containers. This, in turn, would aid in devising vector control strategies against dengue especially in endemic areas.

  18. Structure of an Odorant-Vinding Protein form the Mosquito Aedes aegypti Suggests a Binding Pocket Covered by a pH-Sensitive

    Energy Technology Data Exchange (ETDEWEB)

    N Leite; R Krogh; W Xu; Y Ishida; J Iulek; W Leal; G Oliva

    2011-12-31

    The yellow fever mosquito, Aedes aegypti, is the primary vector for the viruses that cause yellow fever, mostly in tropical regions of Africa and in parts of South America, and human dengue, which infects 100 million people yearly in the tropics and subtropics. A better understanding of the structural biology of olfactory proteins may pave the way for the development of environmentally-friendly mosquito attractants and repellents, which may ultimately contribute to reduction of mosquito biting and disease transmission. Previously, we isolated and cloned a major, female-enriched odorant-binding protein (OBP) from the yellow fever mosquito, AaegOBP1, which was later inadvertently renamed AaegOBP39. We prepared recombinant samples of AaegOBP1 by using an expression system that allows proper formation of disulfide bridges and generates functional OBPs, which are indistinguishable from native OBPs. We crystallized AaegOBP1 and determined its three-dimensional structure at 1.85 {angstrom} resolution by molecular replacement based on the structure of the malaria mosquito OBP, AgamOBP1, the only mosquito OBP structure known to date. The structure of AaegOBP1 (= AaegOBP39) shares the common fold of insect OBPs with six {alpha}-helices knitted by three disulfide bonds. A long molecule of polyethylene glycol (PEG) was built into the electron-density maps identified in a long tunnel formed by a crystallographic dimer of AaegOBP1. Circular dichroism analysis indicated that delipidated AaegOBP1 undergoes a pH-dependent conformational change, which may lead to release of odorant at low pH (as in the environment in the vicinity of odorant receptors). A C-terminal loop covers the binding cavity and this 'lid' may be opened by disruption of an array of acid-labile hydrogen bonds thus explaining reduced or no binding affinity at low pH.

  19. Mosquito Larvicidal Potential of Gossypium hirsutum (Bt cotton Leaves Extracts against Aedes aegypti and Anopheles stephensi larvae.

    Directory of Open Access Journals (Sweden)

    Chandrashekhar D Patil

    2014-06-01

    Full Text Available We aimed to extract the ingredients from leaves of Gossypium hirsutum (Bt cotton using different solvents and evaluate for potential use to control different larval stages of mosquito species, Aedes aegypti and Anopheles stephensi.Qualitative and quantitative estimation of ingredients from Go. hirsutum (Bt plant extract was carried out and their inhibitory action against mosquito larvae was determined using mosquito larvicidal assay.LC50 values of water, ethanol, ethyl acetate and hexane extracts for Ae. aegypti were 211.73±21.49, 241.64±19.92, 358.07±32.43, 401.03±36.19 and 232.56±26.00, 298.54±21.78, 366.50±30.59, 387.19±31.82 for 4(th instar of An. stephensi, respectively. The water extract displayed lowest LC50 value followed by ethanol, ethyl acetate and hexane. Owing to the comparatively better activity of water extract, its efficacy was further evaluated for mosquito larvicidal activity, which exhibited LC50 values of 133.95±12.79, 167.65±11.34 against 2(nd and 3(rd instars of Ae. aegypti and 145.48±11.76, 188.10±12.92 against 2(nd and 3(rd instars of An. stephensi, respectively. Crude protein from the water extract was precipitated using acetone and tested against 2(nd, 3(rd and 4(th instars of Ae. aegypti and An. stephensi. It revealed further decrease in LC50 values as 105.72±25.84, 138.23±23.18, 126.19±25.65, 134.04±04 and 137.88±17.59, 154.25±16.98 for 2(nd, 3(rd and 4(th instars of Ae. aegypti and An. stephensi, respectively.Leaves extracts of Go. hirsutum (Bt is potential mosquito larvicide and can be used as a potent alternative to chemical insecticides in integrated pest management.

  20. Mosquito Larvicidal Potential of Gossypium hirsutum (Bt cotton) Leaves Extracts against Aedes aegypti and Anopheles stephensi larvae.

    Science.gov (United States)

    Patil, Chandrashekhar D; Borase, Hemant P; Salunkhe, Rahul B; Suryawanshi, Rahul K; Narkhade, Chandrakant P; Salunke, Bipinchandra K; Patil, Satish V

    2014-01-01

    We aimed to extract the ingredients from leaves of Gossypium hirsutum (Bt cotton) using different solvents and evaluate for potential use to control different larval stages of mosquito species, Aedes aegypti and Anopheles stephensi. Qualitative and quantitative estimation of ingredients from Go. hirsutum (Bt) plant extract was carried out and their inhibitory action against mosquito larvae was determined using mosquito larvicidal assay. LC50 values of water, ethanol, ethyl acetate and hexane extracts for Ae. aegypti were 211.73±21.49, 241.64±19.92, 358.07±32.43, 401.03±36.19 and 232.56±26.00, 298.54±21.78, 366.50±30.59, 387.19±31.82 for 4(th) instar of An. stephensi, respectively. The water extract displayed lowest LC50 value followed by ethanol, ethyl acetate and hexane. Owing to the comparatively better activity of water extract, its efficacy was further evaluated for mosquito larvicidal activity, which exhibited LC50 values of 133.95±12.79, 167.65±11.34 against 2(nd) and 3(rd) instars of Ae. aegypti and 145.48±11.76, 188.10±12.92 against 2(nd) and 3(rd) instars of An. stephensi, respectively. Crude protein from the water extract was precipitated using acetone and tested against 2(nd), 3(rd) and 4(th) instars of Ae. aegypti and An. stephensi. It revealed further decrease in LC50 values as 105.72±25.84, 138.23±23.18, 126.19±25.65, 134.04±04 and 137.88±17.59, 154.25±16.98 for 2(nd), 3(rd) and 4(th) instars of Ae. aegypti and An. stephensi, respectively. Leaves extracts of Go. hirsutum (Bt) is potential mosquito larvicide and can be used as a potent alternative to chemical insecticides in integrated pest management.

  1. [Geospatial distribution and detection of dengue virus in Aedes (Stegomyia) aegypti mosquitos in Ciudad Juárez, Chihuahua, Mexico].

    Science.gov (United States)

    de la Mora-Covarrubias, Antonio; Jiménez-Vega, Florinda; Treviño-Aguilar, Sandra Maritza

    2010-01-01

    To determine the distribution of Aedes aegypti in Ciudad Juárez, Mexico and evaluate it as a carrier of the dengue virus. Mosquitoes were collected using CDC minitraps. Nearest neighbor and K-function were used as geospatial tools. The chi-square test was utilized to evaluate the association between the presence of the vector and sociodemographic variables. Evidence of infection was detected by RT-PCR. A total of 122 female mosquitoes were captured. A tendency in the cluster distribution (R= -1.2995, p= 0.05) of the mosquito was shown up to 4000 m but none of the sociodemographic variables showed significant associations. Seven of the pools tested were positive for DEN-2, ten were positive for DEN- 3, and seven for both serotypes. This is the first report on the presence of Aedes aegypti mosquitoes infected with dengue in the region, which will enable the promotion of monitoring in order to reduce the probability of occurrence of the disease among the border population.

  2. Restriction fragment length polymorphism mapping of quantitative trait loci for malaria parasite susceptibility in the mosquito Aedes aegypti

    Energy Technology Data Exchange (ETDEWEB)

    Severson, D.W.; Thathy, V.; Mori, A. [Univ. of Wisconsin, Madison, WI (United States)] [and others

    1995-04-01

    Susceptibility of the mosquito Aedes aegypti to the malarial parasite Plasmodium gallinaceum was investigated as a quantitative trait using restriction fragment length polymorphisms (RFLP). Two F{sub 2} populations of mosquitoes were independently prepared from pairwise matings between a highly susceptible and a refractory strain of A. aegypti. RFLP were tested for association with oocyst development on the mosquito midgut. Two putative quantitative trait loci (QTL) were identified that significantly affect susceptibility. One QTL, pgs [2,LF98], is located on chromosome 2 and accounted for 65 and 49% of the observed phenotypic variance in the two populations, respectively. A second QTL, pgs[3,MalI], is located on chromosome 3 and accounted for 14 and 10% of the observed phenotypic variance in the two populations, respectively. Both QTL exhibit a partial dominance effect on susceptibility, wherein the dominance effect is derived from the refractory parent. No indication of epistasis between these QTL was detected. Evidence suggests that either a tightly linked cluster of independent genes or a single locus affecting susceptibility to various mosquito-borne parasites and pathogens has evolved near the LF98 locus; in addition to P. gallinaceum susceptibility, this general genome region has previously been implicated in susceptibility to the filaria nematode Brugia malayi and the yellow fever virus. 35 refs., 2 figs., 3 tabs.

  3. Circulation of DENV2 and DENV4 in Aedes aegypti (Diptera: Culicidae) mosquitoes from Praia, Santiago Island, Cabo Verde.

    Science.gov (United States)

    Guedes, Duschinka R D; Gomes, Elisete T B; Paiva, Marcelo H S; Melo-Santos, Maria A V de; Alves, Joana; Gómez, Lara F; Ayres, Constância F J

    2017-07-01

    Arthropod-borne viruses, such as Dengue (DENV), Chikungunya (CHIKV), and Zika (ZIKV), pose a challenge to public health, due to their worldwide distribution and large-scale outbreaks. Dengue fever is currently one of the most important diseases and it is caused by four serotypes of DENV and is mainly transmitted by the mosquito Aedes aegypti. It is estimated that 50-100 million cases are reported every year worldwide. More recently, CHIKV and ZIKV, which are also transmitted by Ae. aegypti, have caused epidemics in countries in the Caribbean region, the Pacific region, and Americas. Cabo Verde faced its first dengue outbreak in 2009, with more than 21,000 reported cases and four registered deaths. The epidemic was caused by DENV-3 transmitted by Ae. aegypti mosquitoes. In addition, the country faced a Zika outbreak with more than 7,500 notified cases from October 2015 to May 2016. In the present study, we conducted a survey in mosquito samples to detect arboviruses circulating in the local vector population. Collections were performed from November 2014 to January 2015, in the City of Praia, the capital of Cabo Verde, using aspirators and BG-sentinel traps. Samples were examined by multiplex Reverse Transcription-polymerase chain reaction. A total of 161 Ae. aegypti adult females were analyzed (34 pools) and from these samples, eight pools were found positive for DENV-2 and DENV-4. Our results revealed a very high natural infection rate in the vector population and showed two different serotypes co-circulating in the island that differ from the one detected in the 2009 outbreak in Cabo Verde. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  4. Mosquito larvicidal, ovicidal, and repellent properties of botanical extracts against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Govindarajan, M; Mathivanan, T; Elumalai, K; Krishnappa, K; Anandan, A

    2011-08-01

    Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. In mosquito control programs, botanical origin may have the potential to be used successfully as eggs, larvae, and adult. The larvicidal, ovicidal, and repellent activities of crude benzene and ethyl acetate extracts of leaf of Ervatamia coronaria and Caesalpinia pulcherrima were assayed for their toxicity against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in benzene extract of E. coronaria against the larvae of Anopheles Stephensi, Aedes aegypti, and Culex quinquefasciatus with the LC(50) and LC(90) values were 79.08, 89.59, and 96.15 ppm and 150.47, 166.04, and 174.10 ppm, respectively. Mean percent hatchability of the ovicidal activity was observed 48 h posttreatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. The leaf extract of E. coronaria was found to be most effective than Caesalpinia pulcherrima against eggs/egg rafts of three vector mosquitoes. For E. coronaria, the benzene extract exerted 300, 250, and 200 ppm against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, respectively. The results of the repellent activity of benzene and ethyl acetate extract of E. coronaria and Caesalpinia pulcherrima plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm(2) were applied on skin of fore arm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the

  5. Rapid Evolution of Ovarian-Biased Genes in the Yellow Fever Mosquito (Aedes aegypti).

    Science.gov (United States)

    Whittle, Carrie A; Extavour, Cassandra G

    2017-08-01

    Males and females exhibit highly dimorphic phenotypes, particularly in their gonads, which is believed to be driven largely by differential gene expression. Typically, the protein sequences of genes upregulated in males, or male-biased genes, evolve rapidly as compared to female-biased and unbiased genes. To date, the specific study of gonad-biased genes remains uncommon in metazoans. Here, we identified and studied a total of 2927, 2013, and 4449 coding sequences (CDS) with ovary-biased, testis-biased, and unbiased expression, respectively, in the yellow fever mosquito Aedes aegypti The results showed that ovary-biased and unbiased CDS had higher nonsynonymous to synonymous substitution rates (dN/dS) and lower optimal codon usage (those codons that promote efficient translation) than testis-biased genes. Further, we observed higher dN/dS in ovary-biased genes than in testis-biased genes, even for genes coexpressed in nonsexual (embryo) tissues. Ovary-specific genes evolved exceptionally fast, as compared to testis- or embryo-specific genes, and exhibited higher frequency of positive selection. Genes with ovary expression were preferentially involved in olfactory binding and reception. We hypothesize that at least two potential mechanisms could explain rapid evolution of ovary-biased genes in this mosquito: (1) the evolutionary rate of ovary-biased genes may be accelerated by sexual selection (including female-female competition or male-mate choice) affecting olfactory genes during female swarming by males, and/or by adaptive evolution of olfactory signaling within the female reproductive system ( e.g. , sperm-ovary signaling); and/or (2) testis-biased genes may exhibit decelerated evolutionary rates due to the formation of mating plugs in the female after copulation, which limits male-male sperm competition. Copyright © 2017 by the Genetics Society of America.

  6. Global cross-talk of genes of the mosquito Aedes aegypti in response to dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Susanta K Behura

    2011-11-01

    Full Text Available The mosquito Aedes aegypti is the primary vector of dengue virus (DENV infection in humans, and DENV is the most important arbovirus across most of the subtropics and tropics worldwide. The early time periods after infection with DENV define critical cellular processes that determine ultimate success or failure of the virus to establish infection in the mosquito.To identify genes involved in these processes, we performed genome-wide transcriptome profiling between susceptible and refractory A. aegypti strains at two critical early periods after challenging them with DENV. Genes that responded coordinately to DENV infection in the susceptible strain were largely clustered in one specific expression module, whereas in the refractory strain they were distributed in four distinct modules. The susceptible response module in the global transcriptional network showed significant biased representation with genes related to energy metabolism and DNA replication, whereas the refractory response modules showed biased representation across different metabolism pathway genes including cytochrome P450 and DDT [1,1,1-Trichloro-2,2-bis(4-chlorophenyl ethane] degradation genes, and genes associated with cell growth and death. A common core set of coordinately expressed genes was observed in both the susceptible and refractory mosquitoes and included genes related to the Wnt (Wnt: wingless [wg] and integration 1 [int1] pathway, MAPK (Mitogen-activated protein kinase, mTOR (mammalian target of rapamycin and JAK-STAT (Janus Kinase - Signal Transducer and Activator of Transcription pathways.Our data revealed extensive transcriptional networks of mosquito genes that are expressed in modular manners in response to DENV infection, and indicated that successfully defending against viral infection requires more elaborate gene networks than hosting the virus. These likely play important roles in the global-cross talk among the mosquito host factors during the critical

  7. Characterization of an enantioselective odorant receptor in the yellow fever mosquito Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Jonathan D Bohbot

    2009-09-01

    Full Text Available Enantiomers differ only in the left or right handedness (chirality of their orientations and exhibit identical chemical and physical properties. In chemical communication systems, enantiomers can be differentially active at the physiological and behavioral levels. Only recently were enantioselective odorant receptors demonstrated in mammals while their existence in insects has remained hypothetical. Using the two-microelectrode voltage clamp of Xenopus oocytes, we show that the yellow fever mosquito, Aedes aegypti, odorant receptor 8 (AaOR8 acts as a chiral selective receptor for the (R-(--enantiomer of 1-octen-3-ol, which in the presence of other kairomones is an attractant used by blood-sucking insects to locate their hosts. In addition to steric constraints, chain length and degree of unsaturation play important roles in this recognition process. This is the first characterization of an enantioselective odorant receptor in insects and the results demonstrate that an OR alone, without helper proteins, can account for chiral specificity exhibited by olfactory sensory neurons (OSNs.

  8. Limited Specificity in the Injury and Infection Priming against Bacteria in Aedes aegypti Mosquitoes

    Science.gov (United States)

    Vargas, Valeria; Moreno-García, Miguel; Duarte-Elguea, Erika; Lanz-Mendoza, Humberto

    2016-01-01

    Injury and infection priming has been observed in several insect groups, reported as host immune protection against contact with a pathogen caused by a previous infection with the same. However, the specific response against a pathogen has not been demonstrated in all insect species. Investigating the specific priming response in insects is important because their immune strategies probably reflect particular selective pressures exerted by different pathogens. Here, we determined whether previous infection of Aedes aegypti would enhance survival and/or lead to greater and specific AMP expression after a second exposure to the same or a distinct bacterium. Mosquitoes previously immunized with a low dose of Escherichia coli, but not Staphylococcus aureus, showed increased survival. Although the host protection herein demonstrated was not specific, each bacterium elicited differential AMP expression. These results can be explained by the susceptible-primed-infected (SPI) epidemiological model, which poses that in the evolution of memory-like responses (priming), a pivotal role is played by pathogen virulence, associated host damage, and the host capacity of pathogen recognition. PMID:27446016

  9. Potential of crude seed extract of celery, Apium graveolens L., against the mosquito Aedes aegypti (L.) (Diptera: Culicidae).

    Science.gov (United States)

    Choochote, Wej; Tuetun, Benjawan; Kanjanapothi, Duangta; Rattanachanpichai, Eumporn; Chaithong, Udom; Chaiwong, Prasong; Jitpakdi, Atchariya; Tippawangkosol, Pongsri; Riyong, Doungrat; Pitasawat, Benjawan

    2004-12-01

    Crude seed extract of celery, Apium graveolens, was investigated for anti-mosquito potential, including larvicidal, adulticidal, and repellent activities against Aedes aegypti, the vector of dengue haemorrhagic fever. The ethanol-extracted A. graveolens possessed larvicidal activity against fourth instar larvae of Ae. aegypti with LD50 and LD95 values of 81.0 and 176.8 mg/L, respectively. The abnormal movement observed in treated larvae indicated that the toxic effect of A. graveolens extract was probably on the nervous system. In testing for adulticidal activity, this plant extract exhibited a slightly adulticidal potency with LD50 and LD95 values of 6.6 and 66.4 mg/cm2, respectively. It showed repellency against Ae. aegypti adult females with ED50 and ED95 values of 2.03 and 28.12 mg/cm2, respectively. It also provided biting protection time of 3 h when applied at a concentration of 25 g%. Topical application of the ethanol-extracted A. graveolens did not induce dermal irritation. No adverse effects on the skin or other parts of the body of human volunteers were observed during 3 mo of the study period or in the following 3 mo, after which time observations ceased. A. graveolens, therefore, can be considered as a probable source of some biologically active compounds used in the development of mosquito control agents, particularly repellent products.

  10. The importance of human population characteristics in modeling Aedes aegypti distributions and assessing risk of mosquito-borne infectious diseases.

    Science.gov (United States)

    Obenauer, Julie F; Andrew Joyner, T; Harris, Joseph B

    2017-01-01

    The mosquito Aedes aegypti has long been a vector for human illness in the Southeastern United States. In the past, it has been responsible for outbreaks of dengue, chikungunya, and yellow fever and, very recently, the Zika virus that has been introduced to the region. Multiple studies have modeled the geographic distribution of Ae . aegypti as a function of climate factors; however, this ignores the importance of humans to the anthropophilic biter. Furthermore, Ae . aegypti thrives in areas where humans have created standing water sites, such as water storage containers and trash. As models are developed to examine the potential impact of climate change, it becomes increasingly important to include the most comprehensive set of predictors possible. This study uses Maxent, a species distribution model, to evaluate the effects of adding poverty and population density to climate-only models. Performance was evaluated through model fit statistics, such as AUC, omission, and commission, as well as individual variable contributions and response curves. Models which included both population density and poverty exhibited better predictive power and produced more precise distribution maps. Furthermore, the two human population characteristics accounted for much of the model contribution-more so than climate variables. Modeling mosquito distributions without accounting for their dependence on local human populations may miss factors that are very important to niche realization and subsequent risk of infection for humans. Further research is needed to determine if additional human characteristics should be evaluated for model inclusion.

  11. Survival and swimming behavior of insecticide-exposed larvae and pupae of the yellow fever mosquito Aedes aegypti

    Science.gov (United States)

    2014-01-01

    Background The yellow fever mosquito Aedes aegypti is essentially a container-inhabiting species that is closely associated with urban areas. This species is a vector of human pathogens, including dengue and yellow fever viruses, and its control is of paramount importance for disease prevention. Insecticide use against mosquito juvenile stages (i.e. larvae and pupae) is growing in importance, particularly due to the ever-growing problems of resistance to adult-targeted insecticides and human safety concerns regarding such use in human dwellings. However, insecticide effects on insects in general and mosquitoes in particular primarily focus on their lethal effects. Thus, sublethal effects of such compounds in mosquito juveniles may have important effects on their environmental prevalence. In this study, we assessed the survival and swimming behavior of A. aegypti 4th instar larvae (L4) and pupae exposed to increasing concentrations of insecticides. We also assessed cell death in the neuromuscular system of juveniles. Methods Third instar larvae of A. aegypti were exposed to different concentrations of azadirachtin, deltamethrin, imidacloprid and spinosad. Insect survival was assessed for 10 days. The distance swam, the resting time and the time spent in slow swimming were assessed in 4th instar larvae (L4) and pupae. Muscular and nervous cells of L4 and pupae exposed to insecticides were marked with the TUNEL reaction. The results from the survival bioassays were subjected to survival analysis while the swimming behavioral data were subjected to analyses of covariance, complemented with a regression analysis. Results All insecticides exhibited concentration-dependent effects on survival of larvae and pupae of the yellow fever mosquito. The pyrethroid deltamethrin was the most toxic insecticide followed by spinosad, imidacloprid, and azadirachtin, which exhibited low potency against the juveniles. All insecticides except azadirachtin reduced L4 swimming speed and

  12. The mosquito Aedes aegypti has a large genome size and high transposable element load but contains a low proportion of transposon-specific piRNAs

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    Arensburger Peter

    2011-12-01

    Full Text Available Abstract Background The piRNA pathway has been shown in model organisms to be involved in silencing of transposons thereby providing genome stability. In D. melanogaster the majority of piRNAs map to these sequences. The medically important mosquito species Aedes aegypti has a large genome size, a high transposon load which includes Miniature Inverted repeat Transposable Elements (MITES and an expansion of the piRNA biogenesis genes. Studies of transgenic lines of Ae. aegypti have indicated that introduced transposons are poorly remobilized and we sought to explore the basis of this. We wished to analyze the piRNA profile of Ae. aegypti and thereby determine if it is responsible for transposon silencing in this mosquito. Results Estimated piRNA sequence diversity was comparable between Ae. aegypti and D. melanogaster, but surprisingly only 19% of mosquito piRNAs mapped to transposons compared to 51% for D. melanogaster. Ae. aegypti piRNA clusters made up a larger percentage of the total genome than those of D. melanogaster but did not contain significantly higher percentages of transposon derived sequences than other regions of the genome. Ae. aegypti contains a number of protein coding genes that may be sources of piRNA biogenesis with two, traffic jam and maelstrom, implicated in this process in model organisms. Several genes of viral origin were also targeted by piRNAs. Examination of six mosquito libraries that had previously been transformed with transposon derived sequence revealed that new piRNA sequences had been generated to the transformed sequences, suggesting that they may have stimulated a transposon inactivation mechanism. Conclusions Ae. aegypti has a large piRNA complement that maps to transposons but primarily gene sequences, including many viral-derived sequences. This, together the more uniform distribution of piRNA clusters throughout its genome, suggest that some aspects of the piRNA system differ between Ae. aegypti and D

  13. The mosquito Aedes aegypti has a large genome size and high transposable element load but contains a low proportion of transposon-specific piRNAs.

    Science.gov (United States)

    Arensburger, Peter; Hice, Robert H; Wright, Jennifer A; Craig, Nancy L; Atkinson, Peter W

    2011-12-15

    The piRNA pathway has been shown in model organisms to be involved in silencing of transposons thereby providing genome stability. In D. melanogaster the majority of piRNAs map to these sequences. The medically important mosquito species Aedes aegypti has a large genome size, a high transposon load which includes Miniature Inverted repeat Transposable Elements (MITES) and an expansion of the piRNA biogenesis genes. Studies of transgenic lines of Ae. aegypti have indicated that introduced transposons are poorly remobilized and we sought to explore the basis of this. We wished to analyze the piRNA profile of Ae. aegypti and thereby determine if it is responsible for transposon silencing in this mosquito. Estimated piRNA sequence diversity was comparable between Ae. aegypti and D. melanogaster, but surprisingly only 19% of mosquito piRNAs mapped to transposons compared to 51% for D. melanogaster. Ae. aegypti piRNA clusters made up a larger percentage of the total genome than those of D. melanogaster but did not contain significantly higher percentages of transposon derived sequences than other regions of the genome. Ae. aegypti contains a number of protein coding genes that may be sources of piRNA biogenesis with two, traffic jam and maelstrom, implicated in this process in model organisms. Several genes of viral origin were also targeted by piRNAs. Examination of six mosquito libraries that had previously been transformed with transposon derived sequence revealed that new piRNA sequences had been generated to the transformed sequences, suggesting that they may have stimulated a transposon inactivation mechanism. Ae. aegypti has a large piRNA complement that maps to transposons but primarily gene sequences, including many viral-derived sequences. This, together the more uniform distribution of piRNA clusters throughout its genome, suggest that some aspects of the piRNA system differ between Ae. aegypti and D. melanogaster.

  14. Differential Gene Expression from Midguts of Refractory and Susceptible Lines of the Mosquito, Aedes aegypti, Infected with Dengue-2 Virus

    Science.gov (United States)

    Barón, Olga L.; Ursic-Bedoya, Raul J.; Lowenberger, Carl A.; Ocampo, Clara B.

    2010-01-01

    Suppressive subtractive hybridization was used to evaluate the differential expression of midgut genes of feral populations of Aedes aegypti (Diptera: Culicidae) from Colombia that are naturally refractory or susceptible to Dengue-2 virus infection. A total of 165 differentially expressed sequence tags (ESTs) were identified in the subtracted libraries. The analysis showed a higher number of differentially expressed genes in the susceptible Ae. aegypti individuals than the refractory mosquitoes. The functional annotation of ESTs revealed a broad response in the susceptible library that included immune molecules, metabolic molecules and transcription factors. In the refractory strain, there was the presence of a trypsin inhibitor gene, which could play a role in the infection. These results serve as a template for more detailed studies aiming to characterize the genetic components of refractoriness, which in turn can be used to devise new approaches to combat transmission of dengue fever. PMID:20572793

  15. Detection and Establishment of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Mosquitoes in California, 2011-2015.

    Science.gov (United States)

    Metzger, Marco E; Hardstone Yoshimizu, Melissa; Padgett, Kerry A; Hu, Renjie; Kramer, Vicki L

    2017-05-01

    In 2011, a thriving population of Aedes albopictus (Skuse), the Asian tiger mosquito, was discovered within three cities in Los Angeles County over an estimated 52-km2 urban area. Two years later in 2013, Aedes aegypti (L.), the yellow fever mosquito, was detected within several urban areas of Madera, Fresno, and San Mateo counties. State and local vector control agencies responded with an aggressive effort to eradicate or interrupt the spread of these two invasive mosquitoes; however, known populations continued to expand outward and new infestations were identified at an accelerated pace in central and southern California. By the end of 2015, one or both species had been detected within the jurisdictional boundaries of 85 cities and census-designated places in 12 counties. Herein we report on the discovery and widespread establishment of Ae. aegypti and Ae. albopictus in urban areas of coastal, central, and southern California between 2011 and 2015 and discuss the subsequent rapid changes to the activities and priorities of vector control agencies in response to this unprecedented invasion. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. A Zika virus from America is more efficiently transmitted than an Asian virus by Aedes aegypti mosquitoes from Asia.

    Science.gov (United States)

    Pompon, Julien; Morales-Vargas, Ronald; Manuel, Menchie; Huat Tan, Cheong; Vial, Thomas; Hao Tan, Jun; Sessions, October M; Vasconcelos, Pedro da Costa; Ng, Lee Ching; Missé, Dorothée

    2017-04-27

    Zika is a mosquito-borne disease associated with neurological disorders that causes an on-going pandemic. The first outbreak was recorded in Micronesia in 2007, then in French Polynesia in 2014 from which it spread to South America in 2015 and ignited a widespread epidemic. Interestingly, Zika outbreaks in Asia remained of moderate intensity although the virus is circulating. To understand these epidemiological variations, we investigated the entomological determinants of ZIKV transmission in Asia. We used oral infection of mosquitoes collected in Singapore to identify the vector species, to quantify the blood infection threshold and to compare transmissibility between an Asian ZIKV strain (H/PF13) and an American strain collected in Brazil (BE H 815744). We have confirmed the vector status of Aedes aegypti and determined that 10 3  pfu/ml of blood is sufficient to infect mosquitoes. We showed that only the American strain was present in the saliva 3 days post-infection, and that this strain had a 30-40% higher rate of saliva infection in Ae. aegypti from 3 to 14 days post-infection than the Asian strain. Our data suggests that American strains are more efficiently transmitted than Asian strains, which raises concerns about the introduction of American strains in Asia.

  17. Investigation of mosquito oviposition pheromone as lethal lure for the control of Aedes aegypti (L.) (Diptera: Culicidae).

    Science.gov (United States)

    Ong, Song-Quan; Jaal, Zairi

    2015-01-15

    The trend in chemical insecticide development has focused on improving the efficacy against mosquitoes while reducing the environmental impact. Lethal lures apply an "attract-and-kill" strategy that draws the insect to the killing agent rather than bringing the killing agent to the insect. In this study, the mosquito oviposition pheromone was extracted from the eggs of Aedes aegypti (L.) and further investigated with a combination of pheromone and granular temephos as a lethal lure. The compound caproic acid attracted significantly more egg-laying mosquitos at 1 ppm (660.83 ± 91.61) than the control (343.83 ± 56.24), which consisted of solvent only (Oviposition Activity Index: 0.316). Further investigation of the combination of caproic acid with granular temephos as a lethal lure attracted significantly more gravid female Ae. aegypti to oviposit their eggs than the temephos treated water and control. This indicated the ability of caproic acid in acting as an attractant and counters the repellency effect of temephos. Additionally, the presence of temephos in the lethal lure also restricted the hatching of the eggs and killed any larvae that hatched.

  18. Mosquito larvicidal activities of Solanum villosum berry extract against the dengue vector Stegomyia aegypti

    Directory of Open Access Journals (Sweden)

    Chandra Goutam

    2008-04-01

    potential bio control agent against S. aegypti particularly in its markedly larvicidal effect. The extract or isolated bioactive phytochemical could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.

  19. Dynamic expression of genes encoding subunits of inward rectifier potassium (Kir) channels in the yellow fever mosquito Aedes aegypti.

    Science.gov (United States)

    Yang, Zhongxia; Statler, Bethanie-Michelle; Calkins, Travis L; Alfaro, Edna; Esquivel, Carlos J; Rouhier, Matthew F; Denton, Jerod S; Piermarini, Peter M

    2017-02-01

    Inward rectifier potassium (Kir) channels play fundamental roles in neuromuscular, epithelial, and endocrine function in mammals. Recent research in insects suggests that Kir channels play critical roles in the development, immune function, and excretory physiology of fruit flies and/or mosquitoes. Moreover, our group has demonstrated that mosquito Kir channels may serve as valuable targets for the development of novel insecticides. Here we characterize the molecular expression of 5 mRNAs encoding Kir channel subunits in the yellow fever mosquito, Aedes aegypti: Kir1, Kir2A-c, Kir2B, Kir2B', and Kir3. We demonstrate that 1) Kir mRNA expression is dynamic in whole mosquitoes, Malpighian tubules, and the midgut during development from 4th instar larvae to adult females, 2) Kir2B and Kir3 mRNA levels are reduced in 4th instar larvae when reared in water containing an elevated concentration (50mM) of KCl, but not NaCl, and 3) Kir mRNAs are differentially expressed in the Malpighian tubules, midgut, and ovaries within 24h after blood feeding. Furthermore, we provide the first characterization of Kir mRNA expression in the anal papillae of 4th instar larval mosquitoes, which indicates that Kir2A-c is the most abundant. Altogether, the data provide the first comprehensive characterization of Kir mRNA expression in Ae. aegypti and offer insights into the putative physiological roles of Kir subunits in this important disease vector. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. CARACTERIZAÇÃO E AVALIAÇÃO DA ATIVIDADE LARVICIDA DO ÓLEO ESSENCIAL DO Zingiber officinale Roscoe (GENGIBRE) FRENTE AO MOSQUITO Aedes aegypti

    OpenAIRE

    ANDRESON LEANDRO SANTANA SILVA

    2012-01-01

    Na procura pelo controle químico alternativo contra o mosquito Aedes aegypti, diversas pesquisas são desenvolvidas e estimuladas no intuito de descobrirem novas substâncias inseticidas de origem vegetal. Neste trabalho a partir da extração e do estudo analítico do óleo essencial dos rizomas do Zingiber officinale Roscoe, foi analisado o efeito larvicida do óleo contra larvas em terceiro estágio do mosquito Aedes aegypti (Linnaeus, 1792). Extraiu-se quantitativamente o óleo essencial por hidro...

  1. Genome-based polymorphic microsatellite development and validation in the mosquito Aedes aegypti and application to population genetics in Haiti

    Directory of Open Access Journals (Sweden)

    Streit Thomas G

    2009-12-01

    Full Text Available Abstract Background Microsatellite markers have proven useful in genetic studies in many organisms, yet microsatellite-based studies of the dengue and yellow fever vector mosquito Aedes aegypti have been limited by the number of assayable and polymorphic loci available, despite multiple independent efforts to identify them. Here we present strategies for efficient identification and development of useful microsatellites with broad coverage across the Aedes aegypti genome, development of multiplex-ready PCR groups of microsatellite loci, and validation of their utility for population analysis with field collections from Haiti. Results From 79 putative microsatellite loci representing 31 motifs identified in 42 whole genome sequence supercontig assemblies in the Aedes aegypti genome, 33 microsatellites providing genome-wide coverage amplified as single copy sequences in four lab strains, with a range of 2-6 alleles per locus. The tri-nucleotide motifs represented the majority (51% of the polymorphic single copy loci, and none of these was located within a putative open reading frame. Seven groups of 4-5 microsatellite loci each were developed for multiplex-ready PCR. Four multiplex-ready groups were used to investigate population genetics of Aedes aegypti populations sampled in Haiti. Of the 23 loci represented in these groups, 20 were polymorphic with a range of 3-24 alleles per locus (mean = 8.75. Allelic polymorphic information content varied from 0.171 to 0.867 (mean = 0.545. Most loci met Hardy-Weinberg expectations across populations and pairwise FST comparisons identified significant genetic differentiation between some populations. No evidence for genetic isolation by distance was observed. Conclusion Despite limited success in previous reports, we demonstrate that the Aedes aegypti genome is well-populated with single copy, polymorphic microsatellite loci that can be uncovered using the strategy developed here for rapid and efficient

  2. First Evidence of Vertical Infection of Dengue Virus 2 in Aedes aegypti Mosquitoes from Sinaloa, Mexico.

    Science.gov (United States)

    Apodaca-Medina, Annete Itzel; Torres-Avendaño, José Israel; Rendón-Maldonado, José Guadalupe; Torres-Montoya, Edith Hilario; Flores-López, Beatriz Armida; Del Angel, Rosa M; Velarde-Félix, Jesús Salvador; Salomón-Soto, Víctor Manuel; Castillo-Ureta, Hipólito

    2018-04-01

    Fourteen pools of Aedes aegypti larvae collected within the urban area of Culiacán, Sinaloa, were analyzed by RT-PCR. The results demonstrate, for the first time, the vertical infection of serotype-2 dengue virus (DENV-2) in Sinaloa, Mexico, suggesting that Ae. aegypti acts as a natural reservoir of DENV-2 in this region.

  3. Deletion of the NSm virulence gene of Rift Valley fever virus inhibits virus replication in and dissemination from the midgut of Aedes aegypti mosquitoes.

    Directory of Open Access Journals (Sweden)

    Rebekah C Kading

    2014-02-01

    Full Text Available BACKGROUND: Previously, we investigated the role of the Rift Valley fever virus (RVFV virulence genes NSs and NSm in mosquitoes and demonstrated that deletion of NSm significantly reduced the infection, dissemination, and transmission rates of RVFV in Aedes aegypti mosquitoes. The specific aim of this study was to further characterize midgut infection and escape barriers of RVFV in Ae. aegypti infected with reverse genetics-generated wild type RVFV (rRVF-wt or RVFV lacking the NSm virulence gene (rRVF-ΔNSm by examining sagittal sections of infected mosquitoes for viral antigen at various time points post-infection. METHODOLOGY AND PRINCIPAL FINDINGS: Ae. aegypti mosquitoes were fed an infectious blood meal containing either rRVF-wt or rRVF-ΔNSm. On days 0, 1, 2, 3, 4, 6, 8, 10, 12, and 14 post-infection, mosquitoes from each experimental group were fixed in 4% paraformaldehyde, paraffin-embedded, sectioned, and examined for RVFV antigen by immunofluorescence assay. Remaining mosquitoes at day 14 were assayed for infection, dissemination, and transmission. Disseminated infections were observed in mosquitoes as early as three days post infection for both virus strains. However, infection rates for rRVF-ΔNSm were statistically significantly less than for rRVF-wt. Posterior midgut infections in mosquitoes infected with rRVF-wt were extensive, whereas midgut infections of mosquitoes infected with rRVF-ΔNSm were confined to one or a few small foci. CONCLUSIONS/SIGNIFICANCE: Deletion of NSm resulted in the reduced ability of RVFV to enter, replicate, and disseminate from the midgut epithelial cells. NSm appears to have a functional role in the vector competence of mosquitoes for RVFV at the level of the midgut barrier.

  4. Insecticidal potency of bacterial species Bacillus thuringiensis SV2 and Serratia nematodiphila SV6 against larvae of mosquito species Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus.

    Science.gov (United States)

    Patil, Chandrashekhar D; Patil, Satish V; Salunke, Bipinchandra K; Salunkhe, Rahul B

    2012-05-01

    The tremendous worldwide efforts to isolate novel mosquito larvicidal bacteria with improved efficacy present significant promise to control vector-borne diseases of public health importance. In the present study, two native bacterial isolates, Bacillus thuringiensis (Bt SV2) and Serratia species (SV6) were evaluated for mosquito larvicidal potential against the early fourth instar larvae of Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus with reference to B. thuringiensis subsp. israelensis (Bti) H 14. The native Gram-positive, spore-forming Bt SV2 isolate showed 100% mortality against early fourth instars of Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus, in parallel to Bti H14 strain. After 24 h, Bt SV2 showed 98%, 89%, and 80.67%, and Bti H14 showed 92%, 98.33%, and 60% mortality against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus, respectively. Serratia SV6 showed highest activity against Culex quinquefasciatus (100%) followed by Anopheles stephensi (95%) and Aedes aegypti (91%) after 48 h of exposure. The Gram-negative Serratia SV6 showed delayed toxicity compared to Bti H14 and Bt SV2 against early fourth instars of Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. The relative mortality of all treatments after 12-h exposures showed the varied toxicity with respect to exposure time, bacterial treatment, and mosquito species. Genetic relatedness of the strains was confirmed on the basis of phylogenetic reconstructions based on alignment of 16S rRNA gene sequences which indicated a strong clustering of the strain SV2 with B. thuringiensis and the strain SV6 with Serratia nematodiphila. In conclusion, the native isolate B. thuringiensis SV2 showed significant toxicity while Serratia SV6 showed less and delayed toxicity against several mosquito species compared with BtiH14. They may be used as novel bacterial insecticidal agents in mosquito vector-borne disease control. To our knowledge, this is the

  5. Identifying genomic changes associated with insecticide resistance in the dengue mosquito Aedes aegypti by deep targeted sequencing

    Science.gov (United States)

    Faucon, Frederic; Dusfour, Isabelle; Gaude, Thierry; Navratil, Vincent; Boyer, Frederic; Chandre, Fabrice; Sirisopa, Patcharawan; Thanispong, Kanutcharee; Juntarajumnong, Waraporn; Poupardin, Rodolphe; Chareonviriyaphap, Theeraphap; Girod, Romain; Corbel, Vincent; Reynaud, Stephane; David, Jean-Philippe

    2015-01-01

    The capacity of mosquitoes to resist insecticides threatens the control of diseases such as dengue and malaria. Until alternative control tools are implemented, characterizing resistance mechanisms is crucial for managing resistance in natural populations. Insecticide biodegradation by detoxification enzymes is a common resistance mechanism; however, the genomic changes underlying this mechanism have rarely been identified, precluding individual resistance genotyping. In particular, the role of copy number variations (CNVs) and polymorphisms of detoxification enzymes have never been investigated at the genome level, although they can represent robust markers of metabolic resistance. In this context, we combined target enrichment with high-throughput sequencing for conducting the first comprehensive screening of gene amplifications and polymorphisms associated with insecticide resistance in mosquitoes. More than 760 candidate genes were captured and deep sequenced in several populations of the dengue mosquito Ae. aegypti displaying distinct genetic backgrounds and contrasted resistance levels to the insecticide deltamethrin. CNV analysis identified 41 gene amplifications associated with resistance, most affecting cytochrome P450s overtranscribed in resistant populations. Polymorphism analysis detected more than 30,000 variants and strong selection footprints in specific genomic regions. Combining Bayesian and allele frequency filtering approaches identified 55 nonsynonymous variants strongly associated with resistance. Both CNVs and polymorphisms were conserved within regions but differed across continents, confirming that genomic changes underlying metabolic resistance to insecticides are not universal. By identifying novel DNA markers of insecticide resistance, this study opens the way for tracking down metabolic changes developed by mosquitoes to resist insecticides within and among populations. PMID:26206155

  6. Optimal barrier zones for stopping the invasion of Aedes aegypti mosquitoes via transgenic or sterile insect techniques

    KAUST Repository

    Lee, S. Seirin

    2013-03-27

    Biological invasions have dramatically altered the natural world by threatening native species and their communities. Moreover, when the invading species is a vector for human disease, there are further substantive public health and economic impacts. The development of transgenic technologies is being explored in relation to new approaches for the biological control of insect pests. We investigate the use of two control strategies, classical sterile insect techniques and transgenic late-acting bisex lethality (Release of Insects carrying a Dominant Lethal), for controlling invasion of the mosquito Aedes aegypti using a spatial stage-structured mathematical model. In particular, we explore the use of a barrier zone of sterile/transgenic insects to prevent or impede the invasion of mosquitoes. We show that the level of control required is not only highly sensitive to the rate at which the sterile/transgenic males are released in the barrier zone but also to the spatial range of release. Our models characterise how the distribution of sterile/transgenic mosquitoes in the barrier zone can be controlled so as to minimise the number of mass-produced insects required for the arrest of species invasion. We predict that, given unknown rates of mosquito dispersal, management strategies should concentrate on larger release areas rather than more intense release rates for optimal control. © 2013 Springer Science+Business Media Dordrecht.

  7. Correlating Remote Sensing Data with the Abundance of Pupae of the Dengue Virus Mosquito Vector, Aedes aegypti, in Central Mexico

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    Max J. Moreno-Madriñán

    2014-05-01

    Full Text Available Using a geographic transect in Central Mexico, with an elevation/climate gradient, but uniformity in socio-economic conditions among study sites, this study evaluates the applicability of three widely-used remote sensing (RS products to link weather conditions with the local abundance of the dengue virus mosquito vector, Aedes aegypti (Ae. aegypti. Field-derived entomological measures included estimates for the percentage of premises with the presence of Ae. aegypti pupae and the abundance of Ae. aegypti pupae per premises. Data on mosquito abundance from field surveys were matched with RS data and analyzed for correlation. Daily daytime and nighttime land surface temperature (LST values were obtained from Moderate Resolution Imaging Spectroradiometer (MODIS/Aqua cloud-free images within the four weeks preceding the field survey. Tropical Rainfall Measuring Mission (TRMM-estimated rainfall accumulation was calculated for the four weeks preceding the field survey. Elevation was estimated through a digital elevation model (DEM. Strong correlations were found between mosquito abundance and RS-derived night LST, elevation and rainfall along the elevation/climate gradient. These findings show that RS data can be used to predict Ae. aegypti abundance, but further studies are needed to define the climatic and socio-economic conditions under which the correlations observed herein can be assumed to apply.

  8. Epistatic roles of E2 glycoprotein mutations in adaption of chikungunya virus to Aedes albopictus and Ae. aegypti mosquitoes.

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    Konstantin A Tsetsarkin

    2009-08-01

    Full Text Available Between 2005 and 2007 Chikungunya virus (CHIKV caused its largest outbreak/epidemic in documented history. An unusual feature of this epidemic is the involvement of Ae. albopictus as a principal vector. Previously we have demonstrated that a single mutation E1-A226V significantly changed the ability of the virus to infect and be transmitted by this vector when expressed in the background of well characterized CHIKV strains LR2006 OPY1 and 37997. However, in the current study we demonstrate that introduction of the E1-A226V mutation into the background of an infectious clone derived from the Ag41855 strain (isolated in Uganda in 1982 does not significantly increase infectivity for Ae. albopictus. In order to elucidate the genetic determinants that affect CHIKV sensitivity to the E1-A226V mutation in Ae. albopictus, the genomes of the LR2006 OPY1 and Ag41855 strains were used for construction of chimeric viruses and viruses with a specific combination of point mutations at selected positions. Based upon the midgut infection rates of the derived viruses in Ae. albopictus and Ae. aegypti mosquitoes, a critical role of the mutations at positions E2-60 and E2-211 on vector infection was revealed. The E2-G60D mutation was an important determinant of CHIKV infectivity for both Ae. albopictus and Ae. aegypti, but only moderately modulated the effect of the E1-A226V mutation in Ae. albopictus. However, the effect of the E2-I211T mutation with respect to mosquito infections was much more specific, strongly modifying the effect of the E1-A226V mutation in Ae. albopictus. In contrast, CHIKV infectivity for Ae. aegypti was not influenced by the E2-1211T mutation. The occurrence of the E2-60G and E2-211I residues among CHIKV isolates was analyzed, revealing a high prevalence of E2-211I among strains belonging to the Eastern/Central/South African (ECSA clade. This suggests that the E2-211I might be important for adaptation of CHIKV to some particular conditions

  9. The effect of virus-blocking Wolbachia on male competitiveness of the dengue vector mosquito, Aedes aegypti.

    Science.gov (United States)

    Segoli, Michal; Hoffmann, Ary A; Lloyd, Jane; Omodei, Gavin J; Ritchie, Scott A

    2014-12-01

    The bacterial endosymbiont Wolbachia blocks the transmission of dengue virus by its vector mosquito Aedes aegypti, and is currently being evaluated for control of dengue outbreaks. Wolbachia induces cytoplasmic incompatibility (CI) that results in the developmental failure of offspring in the cross between Wolbachia-infected males and uninfected females. This increases the relative success of infected females in the population, thereby enhancing the spread of the beneficial bacterium. However, Wolbachia spread via CI will only be feasible if infected males are sufficiently competitive in obtaining a mate under field conditions. We tested the effect of Wolbachia on the competitiveness of A. aegypti males under semi-field conditions. In a series of experiments we exposed uninfected females to Wolbachia-infected and uninfected males simultaneously. We scored the competitiveness of infected males according to the proportion of females producing non-viable eggs due to incompatibility. We found that infected males were equally successful to uninfected males in securing a mate within experimental tents and semi-field cages. This was true for males infected by the benign wMel Wolbachia strain, but also for males infected by the virulent wMelPop (popcorn) strain. By manipulating male size we found that larger males had a higher success than smaller underfed males in the semi-field cages, regardless of their infection status. The results indicate that Wolbachia infection does not reduce the competitiveness of A. aegypti males. Moreover, the body size effect suggests a potential advantage for lab-reared Wolbachia-males during a field release episode, due to their better nutrition and larger size. This may promote Wolbachia spread via CI in wild mosquito populations and underscores its potential use for disease control.

  10. AVALIAÇÃO DA VIRULENCIA DE BLASTOSPOROS DE Metarhizium anisopliae NO CONTROLE DE LARVAS DE CAMPO DO MOSQUITO Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Aline Teixeira Carolino

    2016-11-01

    Full Text Available Atualmente no Brasil, o mosquito Aedes aegypti é transmissor das arboviroses dengue, chikungunya e Zika. Não existe tratamento específico para estas doenças. A redução da população do vetor ainda é o método mais eficaz para reduzir a taxa dessas arboviroses. O presente estudo comparou a virulência de conídios e blastosporos de Metarhizium anisopliae contra larvas do mosquito A. aegypti provenientes de coletas no campo. Blastosporos foram mais virulentos para larvas, sendo observada mortalidade total das larvas em apenas 48 horas. Larvas infectadas com conídios apresentaram 100% de mortalidade no quinto dia pós-infecção. O presente estudo mostra que blastosporos apresentam grande potencial para controle de larvas de A. aegypti no campo.

  11. Evaluation of some aromatic plant extracts for mosquito larvicidal potential against Culex quinquefasciatus, Aedes aegypti, and Anopheles stephensi.

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    Jayaraman, M; Senthilkumar, A; Venkatesalu, V

    2015-04-01

    In the present investigation, larvicidal potential of hexane, choloroform, ethyl acetate, acetone, and methanol extracts of seven aromatic plants, viz., Blumea mollis, Chloroxylon swietenia, Clausena anisata, Feronia limnonia, Lantana camera, Plectranthus amboinicus, and Tagetes erecta were screened against Culex quinquefasciatus, Aedes aegypti, and Anopheles stephensi. The larval mortality was observed after 12 and 24 h of exposure period. The results revealed that all the extracts showed varied levels of larvicidal activity against the mosquito species tested. However, the ethyl acetate extract of Chloroxylon swietenia showed the remarkable larvicidal activity against C. quinquefasciatus, Ae. aegypti, and An. stephensi. After 12 h of exposure period, the larvicidal activity was LC50 = 194.22 and LC90 = 458.83 ppm (C. quinquefasciatus), LC50 = 173.04 and LC90 = 442.73 ppm (Ae. aegypti), and LC50 = 167.28 and LC90 = 433.07 ppm (An. stephensi), and the larvicidal activity after 24-h exposure period was LC50 = 94.12 and LC90 = 249.83 ppm (C. quinquefasciatus), LC50 = 80.58 and LC90 = 200.96 ppm (Ae. aegypti), and LC50 = 76.24 and LC90 = 194.51 ppm (An. stephensi). The larvicidal potential of other plant extracts were in order of ethyl acetate extract of Clausena anisata > methanol extract of P. amboinicus > acetone extract of F. limonia > methanol extract of T. erecta > methanol extract of B. mollis > and methanol extract of L. camera. The results of the present study offer a possible way for further investigations to find out the active molecule responsible for the activity.

  12. Determination of juvenile hormone titers by means of LC-MS/MS/MS and a juvenile hormone-responsive Gal4/UAS system in Aedes aegypti mosquitoes.

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    Zhao, Bo; Hou, Yuan; Wang, Jianjun; Kokoza, Vladimir A; Saha, Tusar T; Wang, Xue-Li; Lin, Ling; Zou, Zhen; Raikhel, Alexander S

    2016-10-01

    In anautogenous mosquitoes, juvenile hormone III (JH) plays an essential role in female post-eclosion (PE) development, preparing them for subsequent blood feeding and egg growth. We re-examined the JH titer during the reproductive cycle of female Aedes aegypti mosquitoes. Using liquid chromatography coupled with triple tandem mass spectrometry (LC-MS/MS/MS), we have shown that it reaches its peak at 48-54 h PE in the female hemolymph and at 72 h PE in whole body extracts. This method represents an effective assay for determination of JH titers. The 2.1-kb 5' promoter region of the Early Trypsin (ET) gene, which is specifically expressed in the female midgut under the control of JH during the PE phase, was utilized to genetically engineer the Ae. aegypti mosquito line with the ET-Gal4 activator. We then established the ET-GAL4>UAS-enhanced green fluorescent protein (EGFP) system in Ae. aegypti. In ET-Gal4>UAS-EGFP female mosquitoes, the intensity of the midgut-specific EGFP signal was observed to correspond to the ET gene transcript level and follow the JH titer during the PE phase. The EGFP signal and the EGFP transcript level were significantly diminished in midguts of transgenic female mosquitoes after RNA interference depletion of the JH receptor Methoprene-tolerant (Met), providing evidence of the control of ET gene expression by Met. Topical JH application caused premature enhancement of the EGFP signal and the EGFP transcript level in midguts of newly eclosed ET-Gal4>UAS-EGFP female mosquitoes, in which endogenous JH titer is still low. Hence, this novel ET-Gal4>UAS system permits JH-dependent gene overexpression in the midgut of Ae. aegypti female mosquitoes prior to a blood meal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Rapid intraspecific evolution of miRNA and siRNA genes in the mosquito Aedes aegypti.

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    Scott A Bernhardt

    Full Text Available RNA silencing, or RNA interference (RNAi in metazoans mediates development, reduces viral infection and limits transposon mobility. RNA silencing involves 21-30 nucleotide RNAs classified into microRNA (miRNA, exogenous and endogenous small interfering RNAs (siRNA, and Piwi-interacting RNA (piRNA. Knock-out, silencing and mutagenesis of genes in the exogenous siRNA (exo-siRNA regulatory network demonstrate the importance of this RNAi pathway in antiviral immunity in Drosophila and mosquitoes. In Drosophila, genes encoding components for processing exo-siRNAs are among the fastest evolving 3% of all genes, suggesting that infection with pathogenic RNA viruses may drive diversifying selection in their host. In contrast, paralogous miRNA pathway genes do not evolve more rapidly than the genome average. Silencing of exo-siRNA pathway genes in mosquitoes orally infected with arboviruses leads to increased viral replication, but little is known about the comparative patterns of molecular evolution among the exo-siRNA and miRNA pathways genes in mosquitoes. We generated nearly complete sequences of all exons of major miRNA and siRNA pathway genes dicer-1 and dicer-2, argonaute-1 and argonaute-2, and r3d1 and r2d2 in 104 Aedes aegypti mosquitoes collected from six distinct geographic populations and analyzed their genetic diversity. The ratio of replacement to silent amino acid substitutions was 1.4 fold higher in dicer-2 than in dicer-1, 27.4 fold higher in argonaute-2 than in argonaute-1 and similar in r2d2 and r3d1. Positive selection was supported in 32% of non-synonymous sites in dicer-1, in 47% of sites in dicer-2, in 30% of sites in argonaute-1, in all sites in argonaute-2, in 22% of sites in r3d1 and in 55% of sites in r2d2. Unlike Drosophila, in Ae. aegypti, both exo-siRNA and miRNA pathway genes appear to be undergoing rapid, positive, diversifying selection. Furthermore, refractoriness of mosquitoes to infection with dengue virus was

  14. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae, in Madagascar

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    Raharimalala Fara

    2012-03-01

    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

  15. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar.

    Science.gov (United States)

    Raharimalala, Fara Nantenaina; Ravaomanarivo, Lala Harivelo; Ravelonandro, Pierre; Rafarasoa, Lala Sahondra; Zouache, Karima; Tran-Van, Van; Mousson, Laurence; Failloux, Anna-Bella; Hellard, Eléonore; Moro, Claire Valiente; Ralisoa, Bakoly Olga; Mavingui, Patrick

    2012-03-20

    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. 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. 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 Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. In Madagascar, Ae. albopictus has extended its geographical distribution whereas

  16. Efectos de la competencia larval en los mosquitos de contenedores artificiales, Aedes aegypti y Culex pipiens (Diptera: Culicidae en condiciones semi-controladas Effects of larval competition between the container mosquitoes, Aedes aegypti and Culex pipiens (Diptera: Culicidae in semi-controlled conditions

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    Analía Francia

    2011-12-01

    Full Text Available Las larvas de los mosquitos Aedes aegypti (Linneo y Culex pipiens Linneo pueden criar conjuntamente en pequeños contenedores artificiales de agua, se genera así una competencia interespecífica y/o intraespecífica. El objetivo de este trabajo fue comparar la magnitud relativa de la competencia intra e interespecífica en A. aegypti y C. pipiens, generada durante el desarrollo larval en contenedores artifi ciales. Las variables medidas como respuesta fueron la supervivencia y el tiempo de desarrollo larval, y la biomasa total producida en estado de pupa. Se criaron larvas de ambos mosquitos en neumáticos de automóvil con agua declorinada y hojarasca. Se introdujeron larvas recién eclosionadas de acuerdo a la densidad (5 estimada según un censo previo de A. aegypti y C. pipiens. Serealizaron los siguientes tratamientos agregando larvas de: (1 A. aegypti hasta alcanzar δ A. aegypti determinada según el censo previo, (2 C. pipiens hasta δ C. pipiens del censo previo, (3 A. aegypti hasta alcanzar la suma de δ A. aegypti y δ C. pipiens del censo previo, (4 C. pipiens hasta alcanzar la suma de δ A. aegypti y δ C. pipiens del censo previo y (5 A. aegypti y C. pipiens hasta δ A. aegypti y δ C. pipiens del censo previo. Las tres variables medidas fueron afectadas por los tratamientos, excepto la supervivencia y la biomasa producida por C. pipiens. Aedes aegypti fue más alterada por la competencia intraespecífica que por la competencia interespecífica. En C. pipiens, la competencia interespecífica superó en sus efectos a la competencia intraespecífica. Existió asimetría competitiva, ya que C. pipiens fue más afectada por A. aegypti que lo contrario.Larvae of Aedes aegypti (Linneo and Culex pipiens Linneo may develop together in small artificial water containers, promoting inter- and/or intra-specific competition. Our aim was to compare the relative importance of interspecific and intraspecific competition in both species during

  17. Transmission Potential of Two Chimeric Chikungunya Vaccine Candidates in the Urban Mosquito Vectors, Aedes aegypti and Ae. albopictus

    Science.gov (United States)

    Darwin, Justin R.; Kenney, Joan L.; Weaver, Scott C.

    2011-01-01

    Chikungunya virus (CHIKV) is an emerging, mosquito-borne alphavirus that has caused major epidemics in Africa and Asia. We developed chimeric vaccine candidates using the non-structural protein genes of either Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain TC-83 or a naturally attenuated strain of eastern equine encephalitis virus (EEEV) and the structural genes of CHIKV. Because the transmission of genetically modified live vaccine strains is undesirable because of the potentially unpredictable evolution of these viruses as well as the potential for reversion, we evaluated the ability of these vaccines to infect the urban CHIKV vectors, Aedes aegypti and Ae. albopictus. Both vaccine candidates exhibited significantly lower infection and dissemination rates compared with the parent alphaviruses. Intrathoracic inoculations indicated that reduced infectivity was mediated by midgut infection barriers in both species. These results indicate a low potential for transmission of these vaccine strains in the event that a vaccinee became viremic. PMID:21633043

  18. Effect of Quorum Sensing by Staphylococcus epidermidis on the Attraction Response of Female Adult Yellow Fever Mosquitoes, Aedes aegypti aegypti (Linnaeus) (Diptera: Culicidae), to a Blood-Feeding Source.

    Science.gov (United States)

    Zhang, Xinyang; Crippen, Tawni L; Coates, Craig J; Wood, Thomas K; Tomberlin, Jeffery K

    2015-01-01

    Aedes aegypti, the principal vector of yellow fever and dengue fever, is responsible for more than 30,000 deaths annually. Compounds such as carbon dioxide, amino acids, fatty acids and other volatile organic compounds (VOCs) have been widely studied for their role in attracting Ae. aegypti to hosts. Many VOCs from humans are produced by associated skin microbiota. Staphyloccocus epidermidis, although not the most abundant bacteria according to surveys of relative 16S ribosomal RNA abundance, commonly occurs on human skin. Bacteria demonstrate population level decision-making through quorum sensing. Many quorum sensing molecules, such as indole, volatilize and become part of the host odor plum. To date, no one has directly demonstrated the link between quorum sensing (i.e., decision-making) by bacteria associated with a host as a factor regulating arthropod vector attraction. This study examined this specific question with regards to S. epidermidis and Ae. aegypti. Pairwise tests were conducted to examine the response of female Ae. aegypti to combinations of tryptic soy broth (TSB) and S. epidermidis wildtype and agr- strains. The agr gene expresses an accessory gene regulator for quorum sensing; therefore, removing this gene inhibits quorum sensing of the bacteria. Differential attractiveness of mosquitoes to the wildtype and agr- strains was observed. Both wildtype and the agr- strain of S. epidermidis with TSB were marginally more attractive to Ae. aegypti than the TSB alone. Most interestingly, the blood-feeder treated with wildtype S. epidermidis/TSB attracted 74% of Ae. aegypti compared to the agr- strain of S. epidermidis/TSB (P ≤ 0.0001). This study is the first to suggest a role for interkingdom communication between host symbiotic bacteria and mosquitoes. This may have implications for mosquito decision-making with regards to host detection, location and acceptance. We speculate that mosquitoes "eavesdrop" on the chemical discussions occurring between

  19. Effect of Quorum Sensing by Staphylococcus epidermidis on the Attraction Response of Female Adult Yellow Fever Mosquitoes, Aedes aegypti aegypti (Linnaeus (Diptera: Culicidae, to a Blood-Feeding Source.

    Directory of Open Access Journals (Sweden)

    Xinyang Zhang

    Full Text Available Aedes aegypti, the principal vector of yellow fever and dengue fever, is responsible for more than 30,000 deaths annually. Compounds such as carbon dioxide, amino acids, fatty acids and other volatile organic compounds (VOCs have been widely studied for their role in attracting Ae. aegypti to hosts. Many VOCs from humans are produced by associated skin microbiota. Staphyloccocus epidermidis, although not the most abundant bacteria according to surveys of relative 16S ribosomal RNA abundance, commonly occurs on human skin. Bacteria demonstrate population level decision-making through quorum sensing. Many quorum sensing molecules, such as indole, volatilize and become part of the host odor plum. To date, no one has directly demonstrated the link between quorum sensing (i.e., decision-making by bacteria associated with a host as a factor regulating arthropod vector attraction. This study examined this specific question with regards to S. epidermidis and Ae. aegypti. Pairwise tests were conducted to examine the response of female Ae. aegypti to combinations of tryptic soy broth (TSB and S. epidermidis wildtype and agr- strains. The agr gene expresses an accessory gene regulator for quorum sensing; therefore, removing this gene inhibits quorum sensing of the bacteria. Differential attractiveness of mosquitoes to the wildtype and agr- strains was observed. Both wildtype and the agr- strain of S. epidermidis with TSB were marginally more attractive to Ae. aegypti than the TSB alone. Most interestingly, the blood-feeder treated with wildtype S. epidermidis/TSB attracted 74% of Ae. aegypti compared to the agr- strain of S. epidermidis/TSB (P ≤ 0.0001. This study is the first to suggest a role for interkingdom communication between host symbiotic bacteria and mosquitoes. This may have implications for mosquito decision-making with regards to host detection, location and acceptance. We speculate that mosquitoes "eavesdrop" on the chemical discussions

  20. Delivery of chitosan/dsRNA nanoparticles for silencing of wing development vestigial (vg) gene in Aedes aegypti mosquitoes.

    Science.gov (United States)

    Ramesh Kumar, D; Saravana Kumar, P; Gandhi, M Rajiv; Al-Dhabi, Naif Abdullah; Paulraj, M Gabriel; Ignacimuthu, S

    2016-05-01

    RNA interference (RNAi) has been used as a gene silencing strategy by the introduction of long double stranded RNA (dsRNA) for the control of pest insects. The aim of the present study was to examine whether the expression of vg gene which is responsible for wing development, can be repressed by chitosan/dsRNA based nanoparticles in Aedes aegypti. The vestigial gene (vg) was amplified from adult mosquito and cloned in pLitmus28i vector. Genetically engineered recombinant plasmid was transformed into RNase III deficient strain for synthesis of bacterially expressed dsRNA. Nanoparticles were prepared via electrostatic interaction between cationic polymer chitosan and anionic nucleic acids (dsRNA). The formation of chitosan/dsRNAnanoparticles and their size were confirmed by Atomic force microscopy (AFM). Chitosan/dsRNA mediated knockdown of Enhanced Green Fluorescence Protein (EGFP) was demonstrated in Sf21 cells. Further, we tested whether such an approach could be used to target vg gene in Ae. aegypti. The results showed that chitosan/dsRNA caused significant mortality, delayed growth development and caused adult wing-malformation. A qRT-PCR analysis confirmed that the chitosan/dsRNA mediated transcriptional level was downregulated. Our findings suggest that vg gene intervention strategies through RNAi can emerge as viable option for pest control. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Efficacy of botanical extracts from Callitris glaucophylla, against Aedes aegypti and Culex annulirostris mosquitoes.

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    Essam Abdel, S S; Deon Vahid, Canyon; Bruce, Bowden; Mohamed Wagdy, F Y; Hoda Abdel, W Abdel; Abdel Hamid, M

    2006-12-01

    Using standard WHO methodology, this study investigated the susceptibility of 4(th) instar Aedes aegypti (L) and Culex annulirostris (Skuse) larvae to three extracts from Callitris glaucophylla (J. Thompson & L. Johnson) (1: steam distillation extract, 2: liquefied refrigerant gas extract, and 3: methanol reflux extract), lambda-cyhalothrin (a synthetic pyrethroid insecticide) and fenitrothion (an organophosphorous insecticide). Cx. annulirostris was significantly more susceptible than Ae. aegypti to all tested chemicals except lambda-cyhalothrin. Responses to the three C. glaucophylla extracts were exceptional for a botanical compound: Cx. annulirostris (LC(50) = 0.23, 9.53 and 38.95 mg/L) and Ae. aegypti (LC(50) = 0.69, 5.21 and 306.43 mg/L). Both Cx. annulirostris and Ae. aegypti larvae were significantly more susceptible to lambda-cyhalothrin (LC(50) = 0.00013 and 0.00016 mg/L) than fenitrothion (LC(50) = 0.0009 and 0.004 mg/L). As expected, the pyrethroid and organophosphorous insecticides were far more potent than the crude C. glaucophylla extracts. The steam distilled extract was fractionated and the major components guaiol and citronellic acid were identified and tested. Activities for these major components were lower than observed for the distillate. Minor components include lactones such as eldanolide, and future testing of minor components may indicate the active component.

  2. A laboratory investigation of mosquito larval predation by Toxorhynchites moctezuma on Aedes aegypti.

    Science.gov (United States)

    Sherratt, T N; Tikasingh, E S

    1989-07-01

    1. Functional responses of predatory Toxorhynchites moctezuma (Dyar & Knab) larvae feeding on Aedes aegypti (L.) larvae (Diptera: Culicidae) were found to be type II of Holling (1959) and Rogers (1972). 2. Estimates of searching rate were generally higher for later instar predators. The search rate of second instar predators declined as prey instar increased, but fourth instar Tx. moctezuma had the highest search rate for second instar Ae. aegypti. 3. Prey handling times were higher for early instar predators and late instar prey. 4. When presented with mixtures of two instars of Ae. aegypti, second instar Tx. moctezuma showed frequency independent selectivity for the early instars, whereas fourth instar predators showed frequency independent selectivity for the late instars of Ae. aegypti. There was no evidence of frequency dependent predation. Preferences appeared to be transitive. 5. Extended random predator equations, using parameters derived from the functional responses, did not adequately describe the outcome of predation in the prey mixture experiment, even when the possibility of optimal switching behaviour was accounted for.

  3. Encapsulation of Citronellal from Citronella Oil using β-Cyclodextrin and Its Application as Mosquito (Aedes aegypti) Repellent

    Science.gov (United States)

    Pujiastuti, A.; Cahyono, E.; Sumarni, W.

    2017-04-01

    Mosquito (Aedes aegypti) is a threat to human health due to its capability to spread dengue fever. Citronellal in citronella oil is one ofnatural active compound that has repellent activity. Essential oil is a sensitive material whichiseasy to degrade. Encapsulation is coating technology use to avoid essential oil from degradation problems. β-Cyclodextrin is frequently used as acoating material in encapsulation. The aims of this study wereto prepare the citronellal encapsulation and to evaluate its control-released and repellency. In this study, encapsulated citronellal was prepared using 83.65% citronellal and encapsulation were prepared with the theemulsion-based method and dried using freeze-dryer. The best-controlled release was performed in citronellal encapsulate with a weight ratio of 1:1 (citronellal : β-Cyclodextrin). The morphology of encapsulated citronellal was analyzed using SEM. SEM result showed it has three dimensions random shape and agglomerate in some part with thebrighter spot. Citronellal encapsulate showed the highest repellent effect at 84,67% for 5 minutes in mosquito repellency test although it has lower result compared with citronellal inliquid form.

  4. Bacterial Exposure at the Larval Stage Induced Sexual Immune Dimorphism and Priming in Adult Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Moreno-García, Miguel; Vargas, Valeria; Ramírez-Bello, Inci; Hernández-Martínez, Guadalupe; Lanz-Mendoza, Humberto

    2015-01-01

    Gender differences in the immune response of insects are driven by natural selection for females and sexual selection for males. These natural forces entail a multitude of extrinsic and intrinsic factors involved in a genotype-environment interaction that results in sex-biased expression of the genes shared by males and females. However, little is known about how an infection at a particular ontogenetic stage may influence later stages, or how it may impact sexual immune dimorphism. Using Aedes aegypti mosquitoes, the aim of the present study was to analyze the effect of a bacterial exposure at the larval stage on adult immunity in males and females. The parameters measured were phenoloxidase activity, nitric oxide production, antimicrobial activity, and the antimicrobial peptide transcript response. As a measure of the immune response success, the persistence of injected bacteria was also evaluated. The results show that males, as well as females, were able to enhance survival in the adult stage as a result of being exposed at the larval stage, which indicates a priming effect. Moreover, there was a differential gender immune response, evidenced by higher PO activity in males as well as higher NO production and greater antimicrobial activity in females. The greater bacterial persistence in females suggests a gender-specific strategy for protection after a previous experience with an elicitor. Hence, this study provides a primary characterization of the complex and gender-specific immune response of male and female adults against a bacterial challenge in mosquitoes primed at an early ontogenetic stage.

  5. Sindbis virus induces the production of a novel class of endogenous siRNAs in Aedes aegypti mosquitoes.

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    Adelman, Z N; Anderson, M A E; Liu, M; Zhang, L; Myles, K M

    2012-06-01

    Small RNA regulatory pathways are used to control the activity of transposons, regulate gene expression and resist infecting viruses. We examined the biogenesis of mRNA-derived endogenous short-interfering RNAs (endo-siRNAs) in the disease vector mosquito Aedes aegypti. Under standard conditions, mRNA-derived endo-siRNAs were produced from the bidirectional transcription of tail-tail overlapping gene pairs. Upon infection with the alphavirus, Sindbis virus (SINV), another class of mRNA-derived endo-siRNAs was observed. Genes producing SINV-induced endo-siRNAs were not enriched for overlapping partners or nearby genes, but were enriched for transcripts with long 3' untranslated regions. Endo-siRNAs from this class derived uniformly from the entire length of the target transcript, and were found to regulate the transcript levels of the genes from which they were derived. Strand-specific quantitative PCR experiments demonstrated that antisense strands of targeted mRNA genes were produced to exonic, but not intronic regions. Finally, small RNAs mapped to both sense and antisense strands of exon-exon junctions, suggesting double-stranded RNA precursors to SINV-induced endo-siRNAs may be synthesized from mature mRNA templates. These results suggest additional complexity in small RNA pathways and gene regulation in the presence of an infecting virus in disease vector mosquitoes. © 2012 The Authors. Insect Molecular Biology © 2012 The Royal Entomological Society.

  6. Levels of insecticide resistance to deltamethrin, malathion, and temephos, and associated mechanisms in Aedes aegypti mosquitoes from the Guadeloupe and Saint Martin islands (French West Indies).

    Science.gov (United States)

    Goindin, Daniella; Delannay, Christelle; Gelasse, Andric; Ramdini, Cédric; Gaude, Thierry; Faucon, Frédéric; David, Jean-Philippe; Gustave, Joël; Vega-Rua, Anubis; Fouque, Florence

    2017-02-10

    In the Guadeloupe and Saint Martin islands, Aedes aegypti mosquitoes are the only recognized vectors of dengue, chikungunya, and Zika viruses. For around 40 years, malathion was used as a mosquito adulticide and temephos as a larvicide. Since the European Union banned the use of these two insecticide molecules in the first decade of the 21st century, deltamethrin and Bacillus thuringiensis var. israelensis are the remaining adulticide and larvicide, respectively, used in Guadeloupe. In order to improve the management of vector control activities in Guadeloupe and Saint Martin, we investigated Ae. aegypti resistance to and mechanisms associated with deltamethrin, malathion, and temephos. Ae. aegypti mosquitoes were collected from six different localities of Guadeloupe and Saint Martin. Larvae were used for malathion and temephos bioassays, and adult mosquitoes for deltamethrin bioassays, following World Health Organization recommendations. Knockdown resistance (Kdr) genotyping for V1016I and F1534C mutations, and expression levels of eight enzymes involved in detoxification mechanisms were examined in comparison with the susceptible reference Bora Bora strain. Resistance ratios (RR 50 ) calculated for Ae. aegypti larvae showed high resistance levels to temephos (from 8.9 to 33.1-fold) and low resistance levels to malathion (from 1.7 to 4.4-fold). Adult females displayed moderate resistance levels to deltamethrin regarding the time necessary to affect 50% of individuals, varying from 8.0 to 28.1-fold. Molecular investigations on adult mosquitoes showed high resistant allele frequencies for V1016I and F1534C (from 85 to 96% and from 90 to 98%, respectively), as well as an overexpression of the glutathione S-transferase gene, GSTe2, the carboxylesterase CCEae3a, and the cytochrome genes 014614, CYP6BB2, CYP6M11, and CYP9J23. Ae. aegypti populations from Guadeloupe and Saint Martin exhibit multiple resistance to organophosphates (temephos and malathion), and

  7. The heterodimeric glycoprotein hormone, GPA2/GPB5, regulates ion transport across the hindgut of the adult mosquito, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Jean-Paul Paluzzi

    Full Text Available A family of evolutionarily old hormones is the glycoprotein cysteine knot-forming heterodimers consisting of alpha- (GPA and beta-subunits (GPB, which assemble by noncovalent bonds. In mammals, a common glycoprotein hormone alpha-subunit (GPA1 pairs with unique beta-subunits that establish receptor specificity, forming thyroid stimulating hormone (GPA1/TSHβ and the gonadotropins luteinizing hormone (GPA1/LHβ, follicle stimulating hormone (GPA1/FSHβ, choriogonadotropin (GPA1/CGβ. A novel glycoprotein heterodimer was identified in vertebrates by genome analysis, called thyrostimulin, composed of two novel subunits, GPA2 and GPB5, and homologs occur in arthropods, nematodes and cnidarians, implying that this neurohormone system existed prior to the emergence of bilateral metazoans. In order to discern possible physiological roles of this hormonal signaling system in mosquitoes, we have isolated the glycoprotein hormone genes producing the alpha- and beta-subunits (AedaeGPA2 and AedaeGPB5 and assessed their temporal expression profiles in the yellow and dengue-fever vector, Aedes aegypti. We have also isolated a putative receptor for this novel mosquito hormone, AedaeLGR1, which contains features conserved with other glycoprotein leucine-rich repeating containing G protein-coupled receptors. AedaeLGR1 is expressed in tissues of the alimentary canal such as the midgut, Malpighian tubules and hindgut, suggesting that this novel mosquito glycoprotein hormone may regulate ionic and osmotic balance. Focusing on the hindgut in adult stage A. aegypti, where AedaeLGR1 was highly enriched, we utilized the Scanning Ion-selective Electrode Technique (SIET to determine if AedaeGPA2/GPB5 modulated cation transport across this epithelial tissue. Our results suggest that AedaeGPA2/GPB5 does indeed participate in ionic and osmotic balance, since it appears to inhibit natriuresis and promote kaliuresis. Taken together, our findings imply this hormone may play an

  8. Immuno-suppressive effects of aqueous extract of soapnut Sapindus emarginatus on the larvae and pupae of vector mosquito, Aedes aegypti.

    Science.gov (United States)

    Koodalingam, Arunagirinathan; Mullainadhan, Periasamy; Arumugam, Munusamy

    2013-06-01

    We recently reported the presence of potent anti-mosquito activity in aqueous kernel extract of the soapnut, Sapindus emarginatus, and demonstrated its impact on marker enzymes in larvae and pupae of the vector mosquito, Aedes aegypti. As a sequel to these findings, the present study elucidates immunotoxicity of this extract with respect to hemocyte-mediated cellular immune responses in fourth instar larvae and pupae as well as cuticular melanization reaction in the larvae of A. aegypti. The exposure of these two developmental stages of the mosquito to the soapnut extract at a lethal threshold concentration neither affected hemocyte viability tested up to 3h in vitro nor did it influence the hemocyte count. By contrast, exposure of the mosquito larvae and pupae to this extract significantly reduced the ability of their hemocytes to bind yeast cells, an important early event in the process of non-self recognition by immune cells. Consequently, the phagocytic activity of these hemocytes against yeast cells was also found to be adversely affected upon exposure of larvae and pupae to the extract. Besides, a perceptible initial delay in melanization reaction at the injured site of the cuticle in the extract-exposed larvae was observed. All these findings demonstrate, for the first time, the immuno-suppressive potential of a botanical biocide in the vector mosquito. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Larval interference competition between the native Neotropical mosquito Limatus durhamii and the invasive Aedes aegypti improves the fitness of both species.

    Science.gov (United States)

    Talaga, Stanislas; Dejean, Alain; Mouza, Clémence; Dumont, Yves; Leroy, Céline

    2017-05-12

    Interspecific competition with native species during biological invasions can sometimes limit alien expansion. We aimed to determine the potential ecological effects of Limatus durhamii Theobald 1901, a native Neotropical mosquito (Diptera: Culicidae) species, on the invasive species Aedes (Stegomyia) aegypti (Linnaeus 1762) that breeds in the same artificial water containers. Development time and adult dry mass were measured in 3 rearing conditions: control (a single larva), intraspecific competition (2 conspecific larvae), and interspecific competition (2 heterospecific larvae). Food was provided ad libitum to eliminate exploitative competition. For Ae. aegypti, development time was not affected by interspecific interference competition (nonsignificant differences with the control) and the adult dry mass was significantly higher, meaning that individual fitness likely increased. Yet, because previous studies showed longer development time and lighter adults during competition with other invasive mosquitoes, it is likely that Ae. aegypti can express a different phenotype depending on the competing species. The similar pattern found for Li. durhamii females and the nonsignificant difference with the control for males explain in part why this species can compete with Ae. aegypti. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  10. NHE8 is an intracellular cation/H+ exchanger in renal tubules of the yellow fever mosquito Aedes aegypti.

    Science.gov (United States)

    Piermarini, Peter M; Weihrauch, Dirk; Meyer, Heiko; Huss, Markus; Beyenbach, Klaus W

    2009-04-01

    The goal of this study was to identify and characterize the hypothesized apical cation/H(+) exchanger responsible for K(+) and/or Na(+) secretion in the renal (Malpighian) tubules of the yellow fever mosquito Aedes aegypti. From Aedes Malpighian tubules, we cloned "AeNHE8," a full-length cDNA encoding an ortholog of mammalian Na(+)/H(+) exchanger 8 (NHE8). The expression of AeNHE8 transcripts is ubiquitous among mosquito tissues and is not enriched in Malpighian tubules. Western blots of Malpighian tubules suggest that AeNHE8 is expressed primarily as an intracellular protein, which was confirmed by immunohistochemical localizations in Malpighian tubules. AeNHE8 immunoreactivity is expressed in principal cells of the secretory, distal segments, where it localizes to a subapical compartment (e.g., vesicles or endosomes), but not in the apical brush border. Furthermore, feeding mosquitoes a blood meal or treating isolated tubules with dibutyryl-cAMP, both of which stimulate a natriuresis by Malpighian tubules, do not influence the intracellular localization of AeNHE8 in principal cells. When expressed heterologously in Xenopus laevis oocytes, AeNHE8 mediates EIPA-sensitive Na/H exchange, in which Li(+) partially and K(+) poorly replace Na(+). The expression of AeNHE8 in Xenopus oocytes is associated with the development of a conductive pathway that closely resembles the known endogenous nonselective cation conductances of Xenopus oocytes. In conclusion, AeNHE8 does not mediate cation/H(+) exchange in the apical membrane of Aedes Malpighian tubules; it is more likely involved with an intracellular function.

  11. Duration and dose-dependency of female sexual receptivity responses to seminal fluid proteins in Aedes albopictus and Ae. aegypti mosquitoes.

    Science.gov (United States)

    Helinski, Michelle E H; Deewatthanawong, Prasit; Sirot, Laura K; Wolfner, Mariana F; Harrington, Laura C

    2012-10-01

    Male mosquitoes transfer seminal fluid proteins (hereafter 'SFPs') during mating. These proteins can have profound effects on female behavior in the yellow fever mosquito Aedes aegypti and the Asian tiger mosquito Aedes albopictus. SFPs are thought to be responsible for female refractoriness to mating in both species. However, only limited information is available about the duration of induced refractoriness or the quantity of SFPs required to be effective in Ae. albopictus. Here, we tested the duration of the effect of SFPs on female refractory behavior for both Aedes species. Additionally, we determined the lowest SFP dose required to induce female refractory behavior in Ae. aegypti. Virgin females were injected intra-thoracically with doses ranging from 0.25 to 0.008 equivalents of one male's SFP amount. Our results demonstrate high sensitivity of female Ae. aegypti and Ae. albopictus to SFPs of their own species, with the majority of females becoming refractory at doses ≥ 0.031 male-equivalents after injection into the hemocoel. This effect was long-lasting in both species; none of the injected females were inseminated when presented with males of their own species 30 to 34 days post-injection, whereas most saline-injected control females mated at this time point. These results will aid future work to characterize individual SFPs involved in post-mating refractoriness in these two species. Moreover, they show that as is the situation in the mosquito Anopheles gambiae, and unlike Drosophila melanogaster, sperm are not required for the maintenance of a sexual refractoriness response in Ae. aegypti and Ae. albopictus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro - Are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?

    Directory of Open Access Journals (Sweden)

    Márcio Goulart Mocellin

    2009-12-01

    Full Text Available Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importance as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07% and five of Ae. albopictus(0.18% were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats.

  13. The potential impacts of 21st century climatic and population changes on human exposure to the virus vector mosquito Aedes aegypti.

    Science.gov (United States)

    Monaghan, A J; Sampson, K M; Steinhoff, D F; Ernst, K C; Ebi, K L; Jones, B; Hayden, M H

    2018-02-01

    The mosquito Aedes (Ae). aegypti transmits the viruses that cause dengue and chikungunya, two globally-important vector-borne diseases. We investigate how choosing alternate emissions and/or socioeconomic pathways may modulate future human exposure to Ae. aegypti . Occurrence patterns for Ae. aegypti for 2061-2080 are mapped globally using empirically downscaled air temperature and precipitation projections from the Community Earth System Model, for the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. Population growth is quantified using gridded global population projections consistent with two Shared Socioeconomic Pathways (SSPs), SSP3 and SSP5. Change scenarios are compared to a 1950-2000 reference period. A global land area of 56.9 M km 2 is climatically suitable for Ae. aegypti during the reference period, and is projected to increase by 8% (RCP4.5) to 13% (RCP8.5) by 2061-2080. The annual average number of people exposed globally to Ae. aegypti for the reference period is 3794 M, a value projected to statistically significantly increase by 298-460 M (8-12%) by 2061-2080 if only climate change is considered, and by 4805-5084 M (127-134%) for SSP3 and 2232-2483 M (59-65%) for SSP5 considering both climate and population change (lower and upper values of each range represent RCP4.5 and RCP8.5 respectively). Thus, taking the lower-emissions RCP4.5 pathway instead of RCP8.5 may mitigate future human exposure to Ae. aegypti globally, but the effect of population growth on exposure will likely be larger. Regionally, Australia, Europe and North America are projected to have the largest percentage increases in human exposure to Ae. aegypti considering only climate change.

  14. Effects of low-powered RF sweep between 0.01-20 GHz on female Aedes Aegypti mosquitoes: A collective behaviour analysis.

    Directory of Open Access Journals (Sweden)

    Abdul Halim Poh

    Full Text Available There are many products claiming to be an electronic solution towards repelling mosquitoes. Several reviews were published in debunking these claims. However, there is a lack of a systematic study on effects of electromagnetic (EM or more specifically, radio frequency (RF waves against mosquitoes due to the conclusions made in those years. Therefore, we attempt to establish a fundamental study on female Aedes Aegypti (Linnaeus mosquitoes by quantifying the collective behavior of the mosquitoes against a continuous stream of low-powered RF signals via a broadband horn antenna using image processing methods. By examining the average lateral and vertical positions of the mosquitoes versus frequency and time, the data shows negligible consistency in the reactions of the mosquitoes toward the different frequencies ranging from 10 to 20,000.00 MHz, with a step of 10 MHz. This was done by examining 33 hours of spatiotemporal data, which was divided into three sessions. All three sessions showed totally different convolutions in the positions in arbitrary units based on the raster scan of the image processing output. Several frequencies apparently showed up to 0.2-70% shift in both lateral and vertical components along the spectrum, without repeatability for all three sessions. This study contributes to the following: A pilot study for establishing the collective effects of RF against mosquitoes, open-source use, and finally a low-cost and easily adaptable platform for the study of EM effects against any insects.

  15. Impact of micropollutants on the life-history traits of the mosquito Aedes aegypti: On the relevance of transgenerational studies.

    Science.gov (United States)

    Prud'homme, Sophie M; Chaumot, Arnaud; Cassar, Eva; David, Jean-Philippe; Reynaud, Stéphane

    2017-01-01

    Hazard assessment of chemical contaminants often relies on short term or partial life-cycle ecotoxicological tests, while the impact of low dose throughout the entire life cycle of species across multiple generations has been neglected. This study aimed at identifying the individual and population-level consequences of chronic water contamination by environmental concentrations of three organic micropollutants, ibuprofen, bisphenol A and benzo[a]pyrene, on Aedes aegypti mosquito populations in experimental conditions. Life-history assays spanning the full life-cycle of exposed individuals and their progeny associated with population dynamics modelling evidenced life-history traits alterations in unexposed progenies of individuals chronically exposed to 1 μg/L ibuprofen or 0.6 μg/L benzo[a]pyrene. The progeny of individuals exposed to ibuprofen showed an accelerated development while the progeny of individuals exposed to benzo[a]pyrene showed a developmental acceleration associated with an increase in mortality rate during development. These life-history changes due to pollutants exposure resulted in relatively shallow increase of Ae. aegypti asymptotic population growth rate. Multigenerational exposure for six generations revealed an evolution of population response to ibuprofen and benzo[a]pyrene across generations, leading to a loss of previously identified transgenerational effects and to the emergence of a tolerance to the bioinsecticide Bacillus turingiensis israelensis (Bti). This study shed light on the short and long term impact of environmentally relevant doses of ibuprofen and benzo[a]pyrene on Ae. aegypti life-history traits and insecticide tolerance, raising unprecedented perspectives about the influence of surface water pollution on vector-control strategies. Overall, our approach highlights the importance of considering the entire life cycle of organisms, and the necessity to assess the transgenerational effects of pollutants in ecotoxicological

  16. Household survey of container-breeding mosquitoes and climatic factors influencing the prevalence of Aedes aegypti (Diptera: Culicidae) in Makkah City, Saudi Arabia

    Science.gov (United States)

    Aziz, Al Thabiany; Dieng, Hamady; Ahmad, Abu Hassan; Mahyoub, Jazem A; Turkistani, Abdulhafis M; Mesed, Hatabbi; Koshike, Salah; Satho, Tomomitsu; Salmah, MR Che; Ahmad, Hamdan; Zuharah, Wan Fatma; Ramli, Ahmad Saad; Miake, Fumio

    2012-01-01

    Objective To investigate the prevalence of container breeding mosquitoes with emphasis on the seasonality and larval habitats of Aedes aegypti (Ae. aegypti) in Makkah City, adjoining an environmental monitoring and dengue incidence. Methods Monthly visits were performed between April 2008 and March 2009 to randomly selected houses. During each visit, mosquito larvae were collected from indoors and outdoors containers by either dipping or pipetting. Mosquitoes were morphologically identified. Data on temperature, relative humidity, rain/precipitations during the survey period was retrieved from governmental sources and analyzed. Results The city was warmer in dry season (DS) than wet season (WS). No rain occurred at all during DS and even precipitations did fall, wetting events were much greater during WS. Larval survey revealed the co-breeding of Aedes, Culex and Anopheles in a variety of artificial containers in and around homes. 32 109 larvae representing 1st , 2nd, 3rd, and 4th stages were collected from 22 618 container habitats. Culicines was far the commonest and Aedes genus was as numerous as the Culex population. Ae. aegypti larval abundance exhibited marked temporal variations, overall, being usually more abundant during WS. Ten types of artificial containers were found with developing larvae. 70% of these habitats were located indoors. 71.42% of indoor containers were permanent and 28.58% was semi-permanent during WS. Cement tanks was the only container type permanent during DS. Ae. aegypti larval indices (CI, HI, BI) recorded were greater during WS. Conclusions Taken together, these results indicate a high risk of dengue transmission in the holy city. PMID:23569860

  17. 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).

    Science.gov (United States)

    Govindarajan, Marimuthu; Sivakumar, Rajamohan

    2014-04-01

    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

  18. Modelling Aedes aegypti mosquito control via transgenic and sterile insect techniques: Endemics and emerging outbreaks

    KAUST Repository

    Seirin Lee, S.

    2013-08-01

    The invasion of pest insects often changes or destroys a native ecosystem, and can result in food shortages and disease endemics. Issues such as the environmental effects of chemical control methods, the economic burden of maintaining control strategies and the risk of pest resistance still remain, and mosquito-borne diseases such as malaria and dengue fever prevail in many countries, infecting over 100 million worldwide in 2010. One environmentally friendly method for mosquito control is the Sterile Insect Technique (SIT). This species-specific method of insect control relies on the mass rearing, sterilization and release of large numbers of sterile insects. An alternative transgenic method is the Release of Insects carrying a Dominant Lethal (RIDL). Our objective is to consider contrasting control strategies for two invasive scenarios via SIT and RIDL: an endemic case and an emerging outbreak. We investigate how the release rate and size of release region influence both the potential for control success and the resources needed to achieve it, under a range of conditions and control strategies, and we discuss advantageous strategies with respect to reducing the release resources and strategy costs (in terms of control mosquito numbers) required to achieve complete eradication of wild-type mosquitoes. © 2013 Elsevier Ltd.

  19. Frizzled 2 is a key component in the regulation of TOR signaling-mediated egg production in the mosquito Aedes aegypti.

    Science.gov (United States)

    Weng, Shih-Che; Shiao, Shin-Hong

    2015-06-01

    The Wnt signaling pathway was first discovered as a key event in embryonic development and cell polarity in Drosophila. Recently, several reports have shown that Wnt stimulates translation and cell growth by activating the mTOR pathway in mammals. Previous studies have demonstrated that the Target of Rapamycin (TOR) pathway plays an important role in mosquito vitellogenesis. However, the interactions between these two pathways are poorly understood in the mosquito. In this study, we hypothesized that factors from the TOR and Wnt signaling pathways interacted synergistically in mosquito vitellogenesis. Our results showed that silencing Aedes aegypti Frizzled 2 (AaFz2), a transmembrane receptor of the Wnt signaling pathway, decreased the fecundity of mosquitoes. We showed that AaFz2 was highly expressed at the transcriptional and translational levels in the female mosquito 6 h after a blood meal, indicating amino acid-stimulated expression of AaFz2. Notably, the phosphorylation of S6K, a downstream target of the TOR pathway, and the expression of vitellogenin were inhibited in the absence of AaFz2. A direct link was found in this study between Wnt and TOR signaling in the regulation of mosquito reproduction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Gene Silencing in Adult Aedes aegypti Mosquitoes Through Oral Delivery of Double-Stranded RNA

    Science.gov (United States)

    2012-01-01

    2 Beeologics Inc., Miami, Florida, USA Introduction Mosquitoes ( Diptera : Culicidae) are the most medi- cally important arthropods worldwide, vectoring...insecticides can create a long-term burden on species diversity and ecosystem sustainability. Double-stranded RNA (dsRNA) is an attractive alternative as a...insecticide against a variety of insect orders including Coleoptera (Baum et al. 2007; Whyard et al. 2009), Diptera (Walshe et al. 2009; Whyard et al. 2009

  1. No maternal effects after stimulation of the melanization response in the yellow fever mosquito Aedes aegypti

    OpenAIRE

    Voordouw, M. J.; Lambrechts, Louis; Koella, J.

    2008-01-01

    The costs and benefits of activating the immune system can reach across generations. Thus, in vertebrates and in several invertebrates, stimulating the immune system of a female can enhance immunity of her offspring or decrease offspring fitness. We evaluated the potential maternally transmitted costs and benefits of the melanization response, an innate immune response of insects that helps to protect mosquitoes from malaria parasites. We manipulated the maternal melanization response of the ...

  2. Container productivity, daily survival rates and dispersal of Aedes aegypti mosquitoes in a high income dengue epidemic neighbourhood of Rio de Janeiro: presumed influence of differential urban structure on mosquito biology

    Directory of Open Access Journals (Sweden)

    Mariana Rocha David

    2009-09-01

    Full Text Available Different urban structures might affect the life history parameters of Aedes aegypti and, consequently, dengue transmission. Container productivity, probability of daily survival (PDS and dispersal rates were estimated for mosquito populations in a high income neighbourhood of Rio de Janeiro. Results were contrasted with those previously found in a suburban district, as well as those recorded in a slum. After inspecting 1,041 premises, domestic drains and discarded plastic pots were identified as the most productive containers, collectively holding up to 80% of the total pupae. In addition, three cohorts of dust-marked Ae. aegypti females were released and recaptured daily using BGS-Traps, sticky ovitraps and backpack aspirators in 50 randomly selected houses; recapture rate ranged from 5-12.2% within cohorts. PDS was determined by two models and ranged from 0.607-0.704 (exponential model and 0.659-0.721 (non-linear model, respectively. Mean distance travelled varied from 57-122 m, with a maximum dispersal of 263 m. Overall, lower infestation indexes and adult female survival were observed in the high income neighbourhood, suggesting a lower dengue transmission risk in comparison to the suburban area and the slum. Since results show that urban structure can influence mosquito biology, specific control strategies might be used in order to achieve cost-effective Ae. aegypti control.

  3. Avaliação da atividade larvicida do óleo essencial do Zingiber officinale Roscoe (gengibre frente ao mosquito Aedes aegypti

    Directory of Open Access Journals (Sweden)

    P.R.B. GOMES

    Full Text Available RESUMO Este trabalho analisa o efeito larvicida do óleo Zingiber officinale Roscoe contra larvas em terceiro estágio do mosquito Aedes aegypti. Extraiu-se quantitativamente o óleo essencial por hidrodestilação e calculou-se a CL50 do óleo, a partir dos métodos de Reed-Muench e Pizzi, respectivamente. O óleo essencial obteve CL50 de 76,07 (±2,24 μg mL-1 e rendimento de 0,52% m/v. Os resultados indicam que o óleo essencial avaliado é composto por substâncias que propiciam efeito larvicida contra Aedes aegypti.

  4. Spectral and HRTEM analyses of Annona muricata leaf extract mediated silver nanoparticles and its Larvicidal efficacy against three mosquito vectors Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti.

    Science.gov (United States)

    Santhosh, Shanthi Bhupathi; Ragavendran, Chinnasamy; Natarajan, Devarajan

    2015-12-01

    Mosquitoes transmit various diseases which mainly affect the human beings and every year cause millions of deaths globally. Currently available chemical and synthetic mosquitocidal agents pose severe side effects, pollute the environment vigorously, and become resistance. There is an urgent need to identify and develop the cost effective, compatible and eco-friendly product for mosquito control. The present study was aimed to find out the larvicidal potential of aqueous crude extract and green synthesized silver nanoparticles (AgNPs) from Annona muricata leaves were tested against fourth instar larvae of three important mosquitoes i.e. Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti using different concentrations of AgNPs (10, 20, 30, 40 and 50 ppm) and the aqueous leaf extract (100, 200, 300, 400, and 500 ppm) for 24 and 48 h. The maximum mortality was noticed in AgNPs than aqueous leaf extract of A. muricata against tested mosquitoes with least LC50 values of 37.70, 31.29, and 20.65 ppm (24h) and 546.7, 516.2, and 618.4 ppm (48 h), respectively. All tested concentrations of AgNps exhibited 100% mortality in A. aegypti larvae at 48 hour observation. In addition, the plant mediated AgNPs were characterized by UV-vis spectrum, Fourier transform infrared spectroscopy, particle size analyser, X-ray diffraction, high resonance transmission electron microscopy, and energy-dispersive X-ray spectroscopy analysis for confirmation of nanoparticle synthesis. Based on the findings of the study suggests that the use of A. muricata plant mediated AgNPs can act as an alternate insecticidal agents for controlling target mosquitoes. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. RNA-Seq Comparison of Larval and Adult Malpighian Tubules of the Yellow Fever Mosquito Aedes aegypti Reveals Life Stage-Specific Changes in Renal Function.

    Science.gov (United States)

    Li, Yiyi; Piermarini, Peter M; Esquivel, Carlos J; Drumm, Hannah E; Schilkey, Faye D; Hansen, Immo A

    2017-01-01

    Introduction: The life history of Aedes aegypti presents diverse challenges to its diuretic system. During the larval and pupal life stages mosquitoes are aquatic. With the emergence of the adult they become terrestrial. This shifts the organism within minutes from an aquatic environment to a terrestrial environment where dehydration has to be avoided. In addition, female mosquitoes take large blood meals, which present an entirely new set of challenges to salt and water homeostasis. Methods: To determine differences in gene expression associated with these different life stages, we performed an RNA-seq analysis of the main diuretic tissue in A. aegypti , the Malpighian tubules. We compared transcript abundance in 4th instar larvae to that of adult females and analyzed the data with a focus on transcripts that encode proteins potentially involved in diuresis, like water and solute channels as well as ion transporters. We compared our results against the model of potassium- and sodium chloride excretion in the Malpighian tubules proposed by Hine et al. (2014), which involves at least eight ion transporters and a proton-pump. Results: We found 3,421 of a total number of 17,478 (19.6%) unique transcripts with a P tubules, which have not previously been part of the transport model in this species and may play important roles in diuresis. We also identified candidates for hypothesized sodium and chloride channels. Detoxification genes were generally higher expressed in larvae. Significance: This study represents the first comparison of Malpighian tubule transcriptomes between larval and adult A. aegypti mosquitoes, highlighting key differences in their renal systems that arise as they transform from an aquatic filter-feeding larval stage to a terrestrial, blood-feeding adult stage.

  6. Influence of urban landscapes on population dynamics in a short-distance migrant mosquito: evidence for the dengue vector Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Ryan R Hemme

    2010-03-01

    Full Text Available Dengue viruses are endemic across most tropical and subtropical regions. Because no proven vaccines are available, dengue prevention is primarily accomplished through controlling the mosquito vector Aedes aegypti. While dispersal distance is generally believed to be approximately 100 m, patterns of dispersion may vary in urban areas due to landscape features acting as barriers or corridors to dispersal. Anthropogenic features ultimately affect the flow of genes affecting vector competence and insecticide resistance. Therefore, a thorough understanding of what parameters impact dispersal is essential for efficient implementation of any mosquito population suppression program. Population replacement and genetic control strategies currently under consideration are also dependent upon a thorough understanding of mosquito dispersal in urban settings.We examined the effect of a major highway on dispersal patterns over a 2 year period. A. aegypti larvae were collected on the east and west sides of Uriah Butler Highway (UBH to examine any effect UBH may have on the observed population structure in the Charlieville neighborhood in Trinidad, West Indies. A panel of nine microsatellites, two SNPs and a 710 bp sequence of mtDNA cytochrome oxidase subunit 1 (CO1 were used for the molecular analyses of the samples. Three CO1 haplotypes were identified, one of which was only found on the east side of the road in 2006 and 2007. AMOVA using mtCO1 and nuclear markers revealed significant differentiation between the east- and west-side collections.Our results indicate that anthropogenic barriers to A. aegypti dispersal exist in urban environments and should be considered when implementing control programs during dengue outbreaks and population suppression or replacement programs.

  7. RNA-Seq Comparison of Larval and Adult Malpighian Tubules of the Yellow Fever Mosquito Aedes aegypti Reveals Life Stage-Specific Changes in Renal Function

    Directory of Open Access Journals (Sweden)

    Yiyi Li

    2017-05-01

    Full Text Available Introduction: The life history of Aedes aegypti presents diverse challenges to its diuretic system. During the larval and pupal life stages mosquitoes are aquatic. With the emergence of the adult they become terrestrial. This shifts the organism within minutes from an aquatic environment to a terrestrial environment where dehydration has to be avoided. In addition, female mosquitoes take large blood meals, which present an entirely new set of challenges to salt and water homeostasis.Methods: To determine differences in gene expression associated with these different life stages, we performed an RNA-seq analysis of the main diuretic tissue in A. aegypti, the Malpighian tubules. We compared transcript abundance in 4th instar larvae to that of adult females and analyzed the data with a focus on transcripts that encode proteins potentially involved in diuresis, like water and solute channels as well as ion transporters. We compared our results against the model of potassium- and sodium chloride excretion in the Malpighian tubules proposed by Hine et al. (2014, which involves at least eight ion transporters and a proton-pump.Results: We found 3,421 of a total number of 17,478 (19.6% unique transcripts with a P < 0.05 and at least a 2.5 fold change in expression levels between the two groups. We identified two novel transporter genes that are highly expressed in the adult Malpighian tubules, which have not previously been part of the transport model in this species and may play important roles in diuresis. We also identified candidates for hypothesized sodium and chloride channels. Detoxification genes were generally higher expressed in larvae.Significance: This study represents the first comparison of Malpighian tubule transcriptomes between larval and adult A. aegypti mosquitoes, highlighting key differences in their renal systems that arise as they transform from an aquatic filter-feeding larval stage to a terrestrial, blood-feeding adult stage.

  8. Effect of radiation on female Ae. aegypti pupae for SIT

    Science.gov (United States)

    Aedes aegypti is a vector mosquito that can transmit pathogens that can cause disease in humans and animals. However, it is difficult to control them through larvicides and/or source reduction because they can develop in a wide range of water holding containers. One method that has been explored is ...

  9. Mosquito larvicidal properties of Orthisiphon thymiflorus (Roth) Sleesen. (Family: Labiatae) against mosquito vectors, Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    Objective: To determine the larvicidal activity of hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Orthosiphon thymiflorus leaves against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. Methods: Larvicidal activity was determined in laboratory bioassays using var...

  10. The Impact of Temperature and Body Size on Fundamental Flight Tone Variation in the Mosquito Vector Aedes aegypti (Diptera: Culicidae): Implications for Acoustic Lures.

    Science.gov (United States)

    Villarreal, Susan M; Winokur, Olivia; Harrington, Laura

    2017-09-01

    Aedes aegypti (L.) males use female flight tone as a means of mate localization. By playing the sound of a flying female, males can be attracted to a trap to monitor mosquito populations and the progress of transgenic male releases. However, the female flight tone used to attract males needs to be optimized to maximize trap effectiveness. The fundamental frequency of female flight tone could be influenced by both body size and ambient temperature. However, no analysis yet has considered both the effect of body size and temperature on female flight tone of Ae. aegypti. Here, we present results for both these factors by recording the sounds of free-flying and tethered females across multiple temperature environments and with females reared for small, medium, and large body sizes. We demonstrate that female fundamental frequency is highly dependent on the environmental temperature, increasing ∼8-13 Hz with each °C gain. Body size and whether a female was tethered or free-flying did not impact the relationship between frequency and temperature, although further analysis is warranted. Our study highlights the importance of understanding the relationship between flight tone and temperature, and will inform the design of male mosquito traps. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  11. Mosquito traps designed to capture Aedes aegypti (Diptera: Culicidae females: preliminary comparison of Adultrap, MosquiTRAP and backpack aspirator efficiency in a dengue-endemic area of Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Maciel-de-Freitas

    2008-09-01

    Full Text Available In this report, the efficiency of Adultrap under field conditions is compared to a CDC backpack aspirator and to MosquiTRAP. An urban dengue-endemic area of Rio de Janeiro was selected to evaluate the efficiency of mosquito traps in capturing Aedes aegypti females. Adultrap and aspirator captured similar numbers of Ae. aegypti females, with the former showing high specificity to gravid individuals (93.6%. A subsequent mark-release-recapture experiment was conducted to evaluate Adultrap and MosquiTRAP efficiency concomitantly. With a 6.34% recapture rate, MosquiTRAP captured a higher mean number of female Ae. aegypti per trap than Adultrap (Ç2 = 14.26; df = 1; p < 0,05. However, some MosquiTRAPs (28.12% contained immature Ae. aegypti after 18 days of exposure in the field and could be pointed as an oviposition site for female mosquitoes. Both trapping methods, designed to collect gravid Ae. aegypti females, seem to be efficient, reliable and may aid routine Ae. aegypti surveillance.

  12. In the hunt for genomic markers of metabolic resistance to pyrethroids in the mosquito Aedes aegypti: An integrated next-generation sequencing approach.

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    Frederic Faucon

    2017-04-01

    Full Text Available The capacity of Aedes mosquitoes to resist chemical insecticides threatens the control of major arbovirus diseases worldwide. Until alternative control tools are widely deployed, monitoring insecticide resistance levels and identifying resistance mechanisms in field mosquito populations is crucial for implementing appropriate management strategies. Metabolic resistance to pyrethroids is common in Aedes aegypti but the monitoring of the dynamics of resistant alleles is impeded by the lack of robust genomic markers.In an attempt to identify the genomic bases of metabolic resistance to deltamethrin, multiple resistant and susceptible populations originating from various continents were compared using both RNA-seq and a targeted DNA-seq approach focused on the upstream regions of detoxification genes. Multiple detoxification enzymes were over transcribed in resistant populations, frequently associated with an increase in their gene copy number. Targeted sequencing identified potential promoter variations associated with their over transcription. Non-synonymous variations affecting detoxification enzymes were also identified in resistant populations.This study not only confirmed the role of gene copy number variations as a frequent cause of the over expression of detoxification enzymes associated with insecticide resistance in Aedes aegypti but also identified novel genomic resistance markers potentially associated with their cis-regulation and modifications of their protein structure conformation. As for gene transcription data, polymorphism patterns were frequently conserved within regions but differed among continents confirming the selection of different resistance factors worldwide. Overall, this study paves the way of the identification of a comprehensive set of genomic markers for monitoring the spatio-temporal dynamics of the variety of insecticide resistance mechanisms in Aedes aegypti.

  13. In the hunt for genomic markers of metabolic resistance to pyrethroids in the mosquito Aedes aegypti: An integrated next-generation sequencing approach.

    Science.gov (United States)

    Faucon, Frederic; Gaude, Thierry; Dusfour, Isabelle; Navratil, Vincent; Corbel, Vincent; Juntarajumnong, Waraporn; Girod, Romain; Poupardin, Rodolphe; Boyer, Frederic; Reynaud, Stephane; David, Jean-Philippe

    2017-04-01

    The capacity of Aedes mosquitoes to resist chemical insecticides threatens the control of major arbovirus diseases worldwide. Until alternative control tools are widely deployed, monitoring insecticide resistance levels and identifying resistance mechanisms in field mosquito populations is crucial for implementing appropriate management strategies. Metabolic resistance to pyrethroids is common in Aedes aegypti but the monitoring of the dynamics of resistant alleles is impeded by the lack of robust genomic markers. In an attempt to identify the genomic bases of metabolic resistance to deltamethrin, multiple resistant and susceptible populations originating from various continents were compared using both RNA-seq and a targeted DNA-seq approach focused on the upstream regions of detoxification genes. Multiple detoxification enzymes were over transcribed in resistant populations, frequently associated with an increase in their gene copy number. Targeted sequencing identified potential promoter variations associated with their over transcription. Non-synonymous variations affecting detoxification enzymes were also identified in resistant populations. This study not only confirmed the role of gene copy number variations as a frequent cause of the over expression of detoxification enzymes associated with insecticide resistance in Aedes aegypti but also identified novel genomic resistance markers potentially associated with their cis-regulation and modifications of their protein structure conformation. As for gene transcription data, polymorphism patterns were frequently conserved within regions but differed among continents confirming the selection of different resistance factors worldwide. Overall, this study paves the way of the identification of a comprehensive set of genomic markers for monitoring the spatio-temporal dynamics of the variety of insecticide resistance mechanisms in Aedes aegypti.

  14. The effect of shade on the container index and pupal productivity of the mosquitoes Aedes aegypti and Culex pipiens breeding in artificial containers.

    Science.gov (United States)

    Vezzani, D; Albicócco, A P

    2009-03-01

    The aim of this study was to assess whether certain attributes of larval breeding sites are correlated with pupal productivity (i.e. numbers of pupae collected per sampling period), so that these could be used as the focus for control measures to enhance control efficiency. Therefore, the objectives were to identify the months of highest pupal productivity of Aedes aegypti (L.) and Culex pipiens L. (Diptera: Culicidae) in an urban temperate cemetery in Argentina where artificial containers of containers and to determine whether the composition of the containers affected pupal productivity. Over a period of 9 months, 200 randomly chosen water-filled containers (100 sunlit and 100 shaded), out of approximately 3738 containers present (approximately 54% in shade), were examined each month within a cemetery (5 ha) in Buenos Aires (October 2006 to June 2007). In total, 3440 immatures of Cx pipiens and 1974 of Ae. aegypti were collected. The larvae : pupae ratio was 10 times greater for the former, indicating that larval mortality was greater for Cx pipiens. Both mosquito species showed a higher container index (CI) in shaded than in sunlit containers (Ae. aegypti: 12.8% vs. 6.9% [chi(2) = 17.6, P container and the number of pupae per pupa-positive container did not differ significantly between sunlit and shaded containers for either species. Therefore, the overall relative productivity of pupae per ha of Ae. aegypti and Cx pipiens was 2.3 and 1.8 times greater, respectively, in shaded than in sunlit areas as a result of the greater CIs of containers in shaded areas. Neither the CI nor the number of immatures per infested container differed significantly among container types of different materials in either lighting condition. The maximum CI and total pupal counts occurred in March for Ae. aegypti and in January and February for Cx pipiens. The estimated peak abundance of pupae in the whole cemetery reached a total of approximately 4388 in the middle of March for Ae

  15. Blocking the transmission of heartworm (Dirofilaria immitis to mosquitoes (Aedes aegypti by weekly exposure for one month to microfilaremic dogs treated once topically with dinotefuran-permethrin-pyriproxyfen

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    John W. McCall

    2017-11-01

    Full Text Available Abstract Background This study assessed the influence of a topical ectoparasiticide (dinotefuran-permethrin-pyriproxyfen, DPP, Vectra®3D, Ceva Animal Health on the acquisition of heartworm microfilariae by mosquitoes exposed to microfilaremic dogs weekly for 1 month. Methods Six beagle dogs (9.2 ± 1.6 kg body weight infected with Dirofilaria immitis were allocated to two groups of three dogs: an untreated control group and a DPP-treated group. Dogs were treated on Day 0 and exposed under sedation for 1 h to 80 ± 20 unfed Aedes aegypti. Each dog was exposed to mosquitoes released into mosquito-proof containers on Days −7 (pretreatment, 7, 14, 21 and 28. Up to 20 engorged mosquitoes were aspirated from the cage as soon as they were blood-fed. They were dissected and the blood from each midgut was stained for a microfilaria (MF count. After each exposure, mosquitoes were classified as live, moribund or dead and engorged or nonengorged. The number of dead mosquitoes was recorded daily for 16 days, when the live mosquitoes were dissected to count the infective third-stage larvae (L3. Results Prior to treatment, 95% of the engorged mosquitoes in both groups had MF. After treatment, engorgement rates for the treated group were 0%, 2.3%, 2.7% and 2.2% for Days 7, 14, 21 and 28, respectively, with anti-feeding efficacy (repellency of 100%, 98.0%, 95.8% and 97.0%, respectively. A total of 22 mosquitoes fed on treated dogs; most of them were dead within 24 h, and all were dead within 72 h. Only 2 unfed mosquitoes exposed to treated dogs survived the incubation period and no L3 were found in them. A total of 121 of the 132 (91.6% surviving mosquitoes that had engorged on untreated dogs had an average of 12.3 L3 per mosquito (range, 0-39. Conclusions DPP was more than 95% effective in inhibiting blood-feeding and killing both engorged and nonengorged mosquitoes exposed weekly to microfilaremic dogs for 28 days after treatment. Treatment with

  16. Blocking the transmission of heartworm (Dirofilaria immitis) to mosquitoes (Aedes aegypti) by weekly exposure for one month to microfilaremic dogs treated once topically with dinotefuran-permethrin-pyriproxyfen.

    Science.gov (United States)

    McCall, John W; Hodgkins, Elizabeth; Varloud, Marie; Mansour, Abdelmoneim; DiCosty, Utami

    2017-11-09

    This study assessed the influence of a topical ectoparasiticide (dinotefuran-permethrin-pyriproxyfen, DPP, Vectra®3D, Ceva Animal Health) on the acquisition of heartworm microfilariae by mosquitoes exposed to microfilaremic dogs weekly for 1 month. Six beagle dogs (9.2 ± 1.6 kg body weight) infected with Dirofilaria immitis were allocated to two groups of three dogs: an untreated control group and a DPP-treated group. Dogs were treated on Day 0 and exposed under sedation for 1 h to 80 ± 20 unfed Aedes aegypti. Each dog was exposed to mosquitoes released into mosquito-proof containers on Days -7 (pretreatment), 7, 14, 21 and 28. Up to 20 engorged mosquitoes were aspirated from the cage as soon as they were blood-fed. They were dissected and the blood from each midgut was stained for a microfilaria (MF) count. After each exposure, mosquitoes were classified as live, moribund or dead and engorged or nonengorged. The number of dead mosquitoes was recorded daily for 16 days, when the live mosquitoes were dissected to count the infective third-stage larvae (L3). Prior to treatment, 95% of the engorged mosquitoes in both groups had MF. After treatment, engorgement rates for the treated group were 0%, 2.3%, 2.7% and 2.2% for Days 7, 14, 21 and 28, respectively, with anti-feeding efficacy (repellency) of 100%, 98.0%, 95.8% and 97.0%, respectively. A total of 22 mosquitoes fed on treated dogs; most of them were dead within 24 h, and all were dead within 72 h. Only 2 unfed mosquitoes exposed to treated dogs survived the incubation period and no L3 were found in them. A total of 121 of the 132 (91.6%) surviving mosquitoes that had engorged on untreated dogs had an average of 12.3 L3 per mosquito (range, 0-39). DPP was more than 95% effective in inhibiting blood-feeding and killing both engorged and nonengorged mosquitoes exposed weekly to microfilaremic dogs for 28 days after treatment. Treatment with DPP was completely effective in killing the few mosquitoes

  17. A novel in vitro bioassay to explore the repellent effects of compounds against mosquito Aedes Aegypti (Diptera: Culicidae)

    Science.gov (United States)

    Mosquitoes are vectors for many pathogens that can cause human diseases which can result in high rates of human morbidity and mortality at significant levels of transmission. Repellents play an important role in reducing mosquito bites and hence the risk of spread of mosquito borne diseases. Current...

  18. Swarming mechanisms in the yellow fever mosquito: aggregation pheromones involved in the mating behavior of Aedes aegypti

    Science.gov (United States)

    Mosquitoes of various species mate in swarms comprised of tens to thousands flying males. Yet little information is known about mosquito swarming mechanism. Discovering chemical cues involved in mosquito biology leads to better adaptation of disease control interventions. In this study, we aimed ...

  19. Mosquito responses to trait- and density-mediated interactions of predation.

    Science.gov (United States)

    Bellamy, Shawna K; Alto, Barry W

    2018-03-29

    Mosquito and predatory larvae often share the same habitat. Predators may influence mosquito prey populations through both lethal effect and non-lethal pathways. A series of experimental manipulations were used to distinguish between lethal (density-mediated interaction) and non-lethal (trait-mediated interaction) effects in a model system comprised of invasive prey mosquito, Aedes aegypti, and a predatory mosquito Toxorhynchites rutilus. Treatments with predators present or manipulations mimicking daily mortality (density reduction) reduced developmental time and recruitment to the adult stage. Daily records of adult survival of A. aegypti showed that exposure to predators during the juvenile stage shortened the lifespan of adults. This was also observed in treatments, where A. aegypti were replaced at the rate of consumption by T. rutilus. In contrast, numerical reductions in A. aegypti that mimicked daily rate of predation led to adults with the longest lifespan. These observations suggest strong effects of density and trait-mediated interactions in the influence of predators on mosquito biology relevant to their ability to transmit pathogens. These results have potentially important implications for disease control strategies. The primary approach to reduce risk of mosquito-borne diseases is through population reduction of the vectors. We show an unanticipated benefit of biological control by predation for the control of juvenile stages of mosquitoes. Specifically, mosquitoes that are exposed to predators but survive to adulthood will have compromised life expectancy, a key parameter in determining risk of disease transmission.

  20. A Blood Meal Enhances Innexin mRNA Expression in the Midgut, Malpighian Tubules, and Ovaries of the Yellow Fever Mosquito Aedes aegypti

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    Travis L. Calkins

    2017-11-01

    Full Text Available Mosquitoes are vectors of pathogens that cause diseases of medical and veterinary importance. Female mosquitoes transmit these pathogens while taking a blood meal, which most species require to produce eggs. The period after a blood meal is a time of extreme physiological change that requires rapid coordination of specific tissues. Gap junctions (GJ are intercellular channels that aid in the coordination of cells within tissues via the direct transfer of certain small molecules and ions between cells. Evolutionarily distinct groups of proteins form the gap junctions of vertebrate and invertebrate animals (connexins and innexins, respectively. Aedes aegypti mosquitoes possess six genes encoding innexins: inx1, inx2, inx3, inx4, inx7, and inx8. The goal of this study was to identify potential roles of innexins in the physiology of mosquitoes after a blood meal by using qPCR to quantify their mRNA expression in adult females at 3 h and 24 h post-blood meal (PBM relative to non-blood-fed controls. We found that at 24 h PBM, expression levels of inx2, inx3, and inx4 mRNAs increased; inx2 was the most highly upregulated innexin in key tissues associated with blood-meal digestion and egg production (i.e., the midgut and ovaries, respectively. However, knocking down inx2 mRNA levels by over 75% via RNA interference had no significant effect on fecundity. Altogether, our results suggest that a blood meal influences the molecular expression of innexins in mosquitoes, but their specific physiological roles remain to be elucidated.

  1. A Blood Meal Enhances Innexin mRNA Expression in the Midgut, Malpighian Tubules, and Ovaries of the Yellow Fever Mosquito Aedes aegypti.

    Science.gov (United States)

    Calkins, Travis L; Piermarini, Peter M

    2017-11-06

    Mosquitoes are vectors of pathogens that cause diseases of medical and veterinary importance. Female mosquitoes transmit these pathogens while taking a blood meal, which most species require to produce eggs. The period after a blood meal is a time of extreme physiological change that requires rapid coordination of specific tissues. Gap junctions (GJ) are intercellular channels that aid in the coordination of cells within tissues via the direct transfer of certain small molecules and ions between cells. Evolutionarily distinct groups of proteins form the gap junctions of vertebrate and invertebrate animals (connexins and innexins, respectively). Aedes aegypti mosquitoes possess six genes encoding innexins: inx1 , inx2 , inx3 , inx4 , inx7 , and inx8 . The goal of this study was to identify potential roles of innexins in the physiology of mosquitoes after a blood meal by using qPCR to quantify their mRNA expression in adult females at 3 h and 24 h post-blood meal (PBM) relative to non-blood-fed controls. We found that at 24 h PBM, expression levels of inx2 , inx3 , and inx4 mRNAs increased; inx2 was the most highly upregulated innexin in key tissues associated with blood-meal digestion and egg production (i.e., the midgut and ovaries, respectively). However, knocking down inx2 mRNA levels by over 75% via RNA interference had no significant effect on fecundity. Altogether, our results suggest that a blood meal influences the molecular expression of innexins in mosquitoes, but their specific physiological roles remain to be elucidated.

  2. Salinity-tolerant larvae of mosquito vectors in the tropical coast of Jaffna, Sri Lanka and the effect of salinity on the toxicity of Bacillus thuringiensis to Aedes aegypti larvae.

    Science.gov (United States)

    Jude, Pavilupillai J; Tharmasegaram, Tharmatha; Sivasubramaniyam, Gobika; Senthilnanthanan, Meena; Kannathasan, Selvam; Raveendran, Selvarajah; Ramasamy, Ranjan; Surendran, Sinnathamby N

    2012-11-22

    Dengue, chikungunya, malaria, filariasis and Japanese encephalitis are common mosquito-borne diseases endemic to Sri Lanka. Aedes aegypti and Aedes albopictus, the major vectors of dengue, were recently shown to undergo pre-imaginal development in brackish water bodies in the island. A limited survey of selected coastal localities of the Jaffna district in northern Sri Lanka was carried out to identify mosquito species undergoing pre-imaginal development in brackish and saline waters. The effect of salinity on the toxicity of Bacillus thuringiensis israelensis larvicide to Ae. aegypti larvae at salinity levels naturally tolerated by Ae. aegypti was examined. Larvae collected at the selected sites along the Jaffna coast were identified and salinity of habitat water determined in the laboratory. The LC₅₀ and LC₉₀ of B. thuringiensis toxin, the active ingredient of a commercial formulation of the larvicide BACTIVEC®, were determined with Ae. aegypti larvae. Bioassays were also carried out at salinities varying from 0 to 18 ppt to determine the toxicity of Bacillus thuringiensis to fresh and brackish water-derived larvae of Ae. aegypti. Larvae of four Anopheles, two Aedes, one Culex and one Lutzia species were collected from brackish and saline sites with salinity in the range 2 to 68 ppt. The LC₅₀ and LC₉₀ of B. thuringiensis toxin for the second instar larvae of Ae. aegypti in fresh water were 0.006 ppm and 0.013 ppm respectively, with corresponding values for brackish water populations of 0.008 and 0.012 ppm respectively. One hundred percent survival of second instar fresh water and brackish water-derived Ae. aegypti larvae was recorded at salinity up to 10 and 12 ppt and 100% mortality at 16 and 18 ppt, yielding an LC₉₀ for salinity of 13.9 ppt and 15.4 ppt at 24 h post-treatment respectively for the two populations. Statistical analysis showed significantly reduced toxicity of B. thuringiensis to fresh and brackish water-derived Ae. aegypti

  3. Nanoparticles in the fight against mosquito-borne diseases: bioactivity of Bruguiera cylindrica-synthesized nanoparticles against dengue virus DEN-2 (in vitro) and its mosquito vector Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Murugan, Kadarkarai; Dinesh, Devakumar; Paulpandi, Manickam; Althbyani, Abdulaziz Dakhellah Meqbel; Subramaniam, Jayapal; Madhiyazhagan, Pari; Wang, Lan; Suresh, Udaiyan; Kumar, Palanisamy Mahesh; Mohan, Jagathish; Rajaganesh, Rajapandian; Wei, Hui; Kalimuthu, Kandasamy; Parajulee, Megha N; Mehlhorn, Heinz; Benelli, Giovanni

    2015-12-01

    Mosquitoes are blood-feeding insects serving as the most important vectors for spreading human pathogens and parasites. Dengue is a viral disease mainly vectored through the bite of Aedes mosquitoes. Its transmission has recently increased in urban and semi-urban areas of tropical and subtropical regions worldwide, becoming a major international public health concern. There is no specific treatment for dengue. Its prevention and control solely depend on effective vector control measures. Mangrove plants have been used in Indian traditional medicine for a wide array of purposes. In this research, we proposed a method for biosynthesis of antiviral and mosquitocidal silver nanoparticles (AgNP) using the aqueous extract of Bruguiera cylindrica leaves. AgNP were characterized using a variety of biophysical analyses, including UV-visible spectrophotometry, Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Bruguiera cilyndrica aqueous extract and green-synthesized AgNP were tested against the primary dengue vector Aedes aegypti. AgNP were the most effective. LC50 values ranged from 8.93 ppm (larva I) to 30.69 ppm (pupa). In vitro experiments showed that 30 μg/ml of AgNP significantly inhibited the production of dengue viral envelope (E) protein in vero cells and downregulated the expression of dengue viral E gene. Concerning nontarget effects, we observed that the predation efficiency of Carassius auratus against A. aegypti was not affected by exposure at sublethal doses of AgNP. Predation in the control was 71.81 % (larva II) and 50.43 % (larva III), while in an AgNP-treated environment, predation was boosted to 90.25 and 76.81 %, respectively. Overall, this study highlights the concrete potential of green-synthesized AgNP in the fight against dengue virus. Furthermore, B. cylindrica-synthesized AgNP can be employed at low doses to reduce larval and pupal population of A. aegypti, without detrimental

  4. Avaliação da atividade larvicida do óleo essencial do Zingiber officinale Roscoe (gengibre) frente ao mosquito Aedes aegypti

    OpenAIRE

    GOMES, P.R.B.; SILVA, A.L.S.; PINHEIRO, H.A.; CARVALHO, L.L.; LIMA, H.S.; SILVA, E.F.; SILVA, R.P.; LOUZEIRO, C.H.; OLIVEIRA, M.B.; FILHO, V.E.M.

    2016-01-01

    RESUMO Este trabalho analisa o efeito larvicida do óleo Zingiber officinale Roscoe contra larvas em terceiro estágio do mosquito Aedes aegypti. Extraiu-se quantitativamente o óleo essencial por hidrodestilação e calculou-se a CL50 do óleo, a partir dos métodos de Reed-Muench e Pizzi, respectivamente. O óleo essencial obteve CL50 de 76,07 (±2,24) μg mL-1 e rendimento de 0,52% m/v. Os resultados indicam que o óleo essencial avaliado é composto por substâncias que propiciam efeito larvicida cont...

  5. Molecular analysis of Aedes aegypti classical protein tyrosine phosphatases uncovers an ortholog of mammalian PTP-1B implicated in the control of egg production in mosquitoes.

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    Debora Monteiro Moretti

    Full Text Available Protein Tyrosine Phosphatases (PTPs are enzymes that catalyze phosphotyrosine dephosphorylation and modulate cell differentiation, growth and metabolism. In mammals, PTPs play a key role in the modulation of canonical pathways involved in metabolism and immunity. PTP1B is the prototype member of classical PTPs and a major target for treating human diseases, such as cancer, obesity and diabetes. These signaling enzymes are, hence, targets of a wide array of inhibitors. Anautogenous mosquitoes rely on blood meals to lay eggs and are vectors of the most prevalent human diseases. Identifying the mosquito ortholog of PTP1B and determining its involvement in egg production is, therefore, important in the search for a novel and crucial target for vector control.We conducted an analysis to identify the ortholog of mammalian PTP1B in the Aedes aegypti genome. We identified eight genes coding for classical PTPs. In silico structural and functional analyses of proteins coded by such genes revealed that four of these code for catalytically active enzymes. Among the four genes coding for active PTPs, AAEL001919 exhibits the greatest degree of homology with the mammalian PTP1B. Next, we evaluated the role of this enzyme in egg formation. Blood feeding largely affects AAEL001919 expression, especially in the fat body and ovaries. These tissues are critically involved in the synthesis and storage of vitellogenin, the major yolk protein. Including the classical PTP inhibitor sodium orthovanadate or the PTP substrate DiFMUP in the blood meal decreased vitellogenin synthesis and egg production. Similarly, silencing AAEL001919 using RNA interference (RNAi assays resulted in 30% suppression of egg production.The data reported herein implicate, for the first time, a gene that codes for a classical PTP in mosquito egg formation. These findings raise the possibility that this class of enzymes may be used as novel targets to block egg formation in mosquitoes.

  6. Evaluation of 15 Local Plant Species as Larvicidal Agents Against an Indian Strain of Dengue Fever Mosquito, Aedes aegypti L. (Diptera: Culicidae).

    Science.gov (United States)

    Kumar, Sarita; Wahab, Naim; Mishra, Monika; Warikoo, Radhika

    2012-01-01

    The adverse effects of chemical insecticides-based intervention measures for the control of mosquito vectors have received wide public apprehension because of several problems like insecticide resistance, resurgence of pest species, environmental pollution, toxic hazards to humans, and non-target organisms. These problems have necessitated the need to explore and develop alternative strategies using eco-friendly, environmentally safe, bio-degradable plant products which are non-toxic to non-target organisms too. In view of this, 15 plant species were collected from local areas in New Delhi, India. Different parts of these plants were separated, dried, mechanically grinded, and sieved to get fine powder. The 200 g of each part was soaked in 1000 mL of different solvents separately and the crude extracts, thus formed, were concentrated using a vacuum evaporator at 45°C under low pressure. Each extract was screened to explore its potential as a mosquito larvicidal agent against early fourth instars of dengue vector, Aedes aegypti using WHO protocol. The preliminary screening showed that only 10 plants possessed larvicidal potential as they could result in 100% mortality at 1000 ppm. Further evaluation of the potential larvicidal extracts established the hexane leaf extract of Lantana camara to be most effective extract exhibiting a significant LC(50) value of 30.71 ppm while the Phyllanthus emblica fruit extract was found to be least effective with an LC(50) value of 298.93 ppm. The extracts made from different parts of other five plants; Achyranthes aspera, Zingiber officinalis, Ricinus communis, Trachyspermum ammi, and Cassia occidentalis also possessed significant larvicidal potential with LC(50) values ranging from 55.0 to 74.67 ppm. Other three extracts showed moderate toxicity against A. aegypti larvae. Further investigations would be needed to isolate and identify the primary component responsible for the larvicidal efficiency of the effective

  7. Suppression of a Field Population of Aedes aegypti in Brazil by Sustained Release of Transgenic Male Mosquitoes.

    Directory of Open Access Journals (Sweden)

    Danilo O Carvalho

    Full Text Available The increasing burden of dengue, and the relative failure of traditional vector control programs highlight the need to develop new control methods. SIT using self-limiting genetic technology is one such promising method. A self-limiting strain of Aedes aegypti, OX513A, has already reached the stage of field evaluation. Sustained releases of OX513A Ae. aegypti males led to 80% suppression of a target wild Ae. aegypti population in the Cayman Islands in 2010. Here we describe sustained series of field releases of OX513A Ae. aegypti males in a suburb of Juazeiro, Bahia, Brazil. This study spanned over a year and reduced the local Ae. aegypti population by 95% (95% CI: 92.2%-97.5% based on adult trap data and 81% (95% CI: 74.9-85.2% based on ovitrap indices compared to the adjacent no-release control area. The mating competitiveness of the released males (0.031; 95% CI: 0.025-0.036 was similar to that estimated in the Cayman trials (0.059; 95% CI: 0.011-0.210, indicating that environmental and target-strain differences had little impact on the mating success of the OX513A males. We conclude that sustained release of OX513A males may be an effective and widely useful method for suppression of the key dengue vector Ae. aegypti. The observed level of suppression would likely be sufficient to prevent dengue epidemics in the locality tested and other areas with similar or lower transmission.

  8. Suppression of a Field Population of Aedes aegypti in Brazil by Sustained Release of Transgenic Male Mosquitoes.

    Science.gov (United States)

    Carvalho, Danilo O; McKemey, Andrew R; Garziera, Luiza; Lacroix, Renaud; Donnelly, Christl A; Alphey, Luke; Malavasi, Aldo; Capurro, Margareth L

    2015-01-01

    The increasing burden of dengue, and the relative failure of traditional vector control programs highlight the need to develop new control methods. SIT using self-limiting genetic technology is one such promising method. A self-limiting strain of Aedes aegypti, OX513A, has already reached the stage of field evaluation. Sustained releases of OX513A Ae. aegypti males led to 80% suppression of a target wild Ae. aegypti population in the Cayman Islands in 2010. Here we describe sustained series of field releases of OX513A Ae. aegypti males in a suburb of Juazeiro, Bahia, Brazil. This study spanned over a year and reduced the local Ae. aegypti population by 95% (95% CI: 92.2%-97.5%) based on adult trap data and 81% (95% CI: 74.9-85.2%) based on ovitrap indices compared to the adjacent no-release control area. The mating competitiveness of the released males (0.031; 95% CI: 0.025-0.036) was similar to that estimated in the Cayman trials (0.059; 95% CI: 0.011-0.210), indicating that environmental and target-strain differences had little impact on the mating success of the OX513A males. We conclude that sustained release of OX513A males may be an effective and widely useful method for suppression of the key dengue vector Ae. aegypti. The observed level of suppression would likely be sufficient to prevent dengue epidemics in the locality tested and other areas with similar or lower transmission.

  9. Functional characterization of the octenol receptor neuron on the maxillary palps of the yellow fever mosquito, Aedes aegypti

    Science.gov (United States)

    1-Octen-3-ol (octenol) is a common attractant released by vertebrates which in combination with carbon dioxide attracts haematophagous arthropods including mosquitoes. A receptor neuron contained within basiconic sensilla on the maxillary palps of adult mosquitoes responds selectively to 1-octen-3-o...

  10. Larvicidal and pupicidal activity of synthesized silver nanoparticles using Leucas aspera leaf extract against mosquito vectors, Aedes aegypti and Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    S. Sivapriyajothi

    2014-08-01

    Full Text Available Mosquitoes are one of the most medically significant groups of vectors, having an ability to transmit parasites and pathogens that can have devastating impacts on humans. The development of reliable and ecofriendly processes for the synthesis of metallic nanoparticles is an important step in the field of application of nanotechnology. In this study, we address the biosynthesis of silver nanoparticles (AgNPs using Leucas aspera leaf extract, and evaluate its lethal concentration (LC50 and LC90 values against first to fourth instar larvae and pupae of the mosquito vectors, Aedes aegypti and Anopheles stephensi. The nanoparticles were characterized by UV-Vis spectrum, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transformed infrared spectroscopy analysis. Larvae and pupae were exposed to varying concentrations of aqueous extracts of synthesized AgNPs for 24 h. The maximum mortality was observed from synthesized AgNPs, with LC50 values for I-IV instars and pupae ranging from 13.06 to 25.54, and LC90 values ranging from 24.11 to 47.34 for A. aegypti; for A. stephensi, the corresponding LC50 values ranged from 12.45 to 22.26, and the LC90 values ranged from 23.50 to 42.95. With methanol leaf extract of L. aspera against A. aegypti, the LC50 values ranged from 174.89 to 462.96 and the LC90 values ranged from 488.16 to 963.74; for A. stephensi, the corresponding LC50 values ranged from 148.93 to 417.07 and the LC90 values ranged from 449.72 to 912.94. The study suggests that nanoparticles could be a preferred alternative to the most hazardous existing chemical pesticides, contributing to a more healthy environment by providing an ideal ecological and user-friendly vector control strategy for managing malaria and dengue, and contributing to their eventual elimination in the near future.

  11. Use of the CDC autocidal gravid ovitrap to control and prevent outbreaks of Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Barrera, Roberto; Amador, Manuel; Acevedo, Veronica; Caban, Belkis; Felix, Gilberto; Mackay, Andrew J

    2014-01-01

    Populations ofAedes aegypti (L.) can be managed through reductions in adult mosquito survival, number of offspring produced, or both. Direct adult mortality can be caused by the use of space sprays or residual insecticides to mosquito resting sites, and with a variety of residual insecticide-impregnated surfaces that are being tested, such as curtains, covers for water-storage vessels, bednets, and ovitraps. The fertility ofAe. aegypti populations can be reduced by the use of autocidal oviposition cups that prevent the development of mosquitoes inside the trap by mechanical means or larvicides, as well as by releasing sterile, transgenic, and para-transgenic mosquitoes. Survival and fertility can be simultaneously reduced by capturing gravid female Ae. aegypti with sticky gravid traps. We tested the effectiveness of the novel Centers for Disease Control and Prevention autocidal gravid ovitrap (CDC-AGO trap) to control natural populations ofAe. aegypti under field conditions in two isolated urban areas (reference vs. intervention areas) in southern Puerto Rico for 1 yr. There were significant reductions in the captures of female Ae. aegypti (53-70%) in the intervention area The presence of three to four AGO control traps per home in 81% of the houses prevented outbreaks of Ae. aegypti, which would be expected after rains. Mosquito captures in BG-Sentinel and AGO traps were significantly and positively correlated, showing that AGO traps are useful and inexpensive mosquito surveillance devices. The use of AGO traps to manage Ae. aegypti populations is compatible with other control means such as source reduction, larviciding, adulticiding, sterile insect techniques, induced cytoplasmic incompatibility, and dominant lethal gene systems.

  12. Relative Toxicity of Leaf Extracts of Eucalyptus globulus and Centella asiatica against Mosquito Vectors Aedes aegypti and Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    Savitha Sekhar Nair

    2014-01-01

    Full Text Available The larvicidal activity of different solvent leaf extracts (hexane, diethyl ether, dichloromethane, and methanol of Eucalyptus globulus and Centella asiatica against two geographically different strains of Aedes aegypti and Anopheles stephensi was investigated. The extracts were tested against the late third instar larvae of Aedes aegypti and Anopheles stephensi, and larval mortality was observed after 24 hours of treatment. LC50 and LC90 were calculated. The LC50 values of hexane extract of Eucalyptus globulus against the late third instar larvae of the BSN and JPN strains of Aedes aegypti and the DLC and KNG strains of Anopheles stephensi were 225.2, 167.7, 118.8, and 192.8 ppm, while those of the hexane extract of Centella asiatica were 246.5, 268.7, 50.6, and 243.5 ppm, respectively. The LC50 values of diethyl ether extract of Centella asiatica were 339.6, 134.5, 241, and 14.7 ppm. The hexane extracts of both plants and the diethyl ether extract of C. asiatica presented the highest potential for the control of Aedes aegypti and Anopheles stephensi. The present findings also reveal the necessity of assaying multiple strains of a species to fully comprehend the larvicidal efficacy of a compound.

  13. Dopamine levels in the mosquito Aedes aegypti during adult development, following blood feeding and in response to heat stress

    DEFF Research Database (Denmark)

    Andersen, Janne Pleidrup; Schwartz, Alex; Gramsbergen, Jan Bert

    2006-01-01

    Dopamine, a catecholamine neurotransmitter, is important for insect development and is known to be involved in insect stress responses. In the current study, dopamine was analysed in Aedes aegypti heads by HPLC. We found that immediately after adult emergence, males have significantly higher...

  14. Effect of proteolytic and detoxification enzyme inhibitors on Bacillus thuringiensis var. israelensis tolerance in the mosquito Aedes aegypti

    Czech Academy of Sciences Publication Activity Database

    Hu, X.; Guo, Y.; Wu, S.; Liu, Z.; Fu, T.; Shao, E.; Carballar-Lejarazú, R.; Zhao, G.; Huang, Z.; Gelbič, Ivan; Guan, X.; Zou, S.; Xu, L.; Zhang, L.

    2017-01-01

    Roč. 27, č. 2 (2017), s. 169-179 ISSN 0958-3157 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * Bti * Aedes aegypti Subject RIV: ED - Physiology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 0.919, year: 2016

  15. Optimization of the Aedes aegypti Control Strategies for Integrated Vector Management

    Directory of Open Access Journals (Sweden)

    Marat Rafikov

    2015-01-01

    Full Text Available We formulate an infinite-time quadratic functional minimization problem of Aedes aegypti mosquito population. Three techniques of mosquito population management, chemical insecticide control, sterile insect technique control, and environmental carrying capacity reduction, are combined in order to obtain the most sustainable strategy to reduce mosquito population and consequently dengue disease. The solution of the optimization control problem is based on the ideas of the Dynamic Programming and Lyapunov Stability using State-Dependent Riccati Equation (SDRE control method. Different scenarios are analyzed combining three mentioned population management efforts in order to assess the most sustainable policy to reduce the mosquito population.

  16. GINCANA SOBRE O MOSQUITO Aedes aegypti COM ALUNOS DO ENSINO FUNDAMENTAL DE UMA ESCOLA PÚBLICA DO MUNICÍPIO DE ALEGRE-ES

    Directory of Open Access Journals (Sweden)

    Paola Cerbino Doblas

    2017-02-01

    Full Text Available Os vírus da Dengue, Zica e Chikungunya tem alarmado o Governo e a população tendo em vista o elevado número de casos no Brasil e seus consequentes prejuízos à saúde pública. Dessa forma a escola tem um papel fundamental em instruir seus alunos sobre os riscos, métodos de transmissão e prevenção quanto ao vetor dessas doenças: o mosquito Aedes aegypti. Com o objetivo de prevenir a proliferação do mosquito na cidade de Alegre, ES, os alunos participantes do Programa Institucional de Bolsa de Iniciação à Docência (PIBID de biologia, da Universidade Federal do Espírito Santo (UFES no campus de Alegre, aplicaram uma gincana para alunos do ensino fundamental de uma escola da rede pública do município de Alegre. O resultado da gincana foi benéfico visto que os alunos se demonstraram bastante participativos e mostraram obter conhecimento sobre o assunto. Por meio da análise dos resultados é possível perceber que os diferentes métodos de ensino podem ser muito eficientes para o processo de ensino-aprendizagem.

  17. Contribution of midgut bacteria to blood digestion and egg production in aedes aegypti (diptera: culicidae) (L.)

    Science.gov (United States)

    2011-01-01

    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. PMID:21672186

  18. Efficacy of essential oil from Cananga odorata (Lamk.) Hook.f. & Thomson (Annonaceae) against three mosquito species Aedes aegypti (L.), Anopheles dirus (Peyton and Harrison), and Culex quinquefasciatus (Say).

    Science.gov (United States)

    Soonwera, Mayura

    2015-12-01

    The essential oil of Cananga odorata flowers was evaluated for oviposition-deterrent, ovicidal, insecticidal, and repellent activities toward three mosquito species: Aedes aegypti, Anopheles dirus, and Culex quinquefasciatus. Oviposition deterrence of the oil was evaluated on gravid females using oviposition deterrence bioassay. The results showed that 10 % Ca. odorata exhibited high percent effective repellency against oviposition at 99.4 % to Ae. aegypti, 97.1 % to An. dirus, and 100 % to Cx. quinquefasciatus. Ca. odorata oil was tested for ovicidal activity. Regression equations revealed that the ovicidal rates were positively correlated with the concentrations of the essential oil. As the concentration of essential oil increased from 1, 5, and up to 10 % concentration, the ovicidal rate increased accordingly. Larvicidal activity of the oils was used on immature stages (third and fourth instar lavae and pupae). The maximum larval mortality was found with 10 % Ca. odorata against immature stages, and there were LC50 values ranged from 10.4 to 10.5 % (for Ae. aegypti), <1 % (for An. dirus), and <1 % (for Cx. quinquefasciatus). Adulticidal properties were evaluated with unfed females. Ten percent Ca. odorata oil had high knockdown rates against the three mosquito species at 96 % (for Ae. aegypti), 98.4 % (for An. dirus), and 100 % (for Cx. quinquefasciatus), with EC50 values of 6.2, 4.7, and 5.4 %, respectively. It gave moderate mortality rates after 24 and 48 h of exposure. Ca. odorata oil was assessed for repellency to females by using the modified K&D module. Ten percent Ca. odorata oil gave the strongest value against Ae. aegypti, An. dirus, and Cx. quinquefasciatus, with percentage repellency of 66, 92, and 90 %, respectively. This study demonstrates the potential for the essential oil of Ca. odorata essential oil to be used as a botanical insecticide against three mosquito species.

  19. Protection capacity of mosquito repellent ink from citronella (Cymbopogon nardus L.) and clove leaf oils (Syzygium aromaticum) againts Aedes aegypti

    Science.gov (United States)

    Harismah, Kun; Vitasari, Denny; Mirzaei, Mahmoud; Fuadi, Ahmad Muhammad; Aryanto, Yanur Hendra

    2017-06-01

    The study of combination citronella and clove oils in mosquito repellent newspaper ink has been done. The background of this study was there prevalences of diseases such as malaria, zikka, and dengue fever that are carried by mosquitoes which hunt in the morning, at time while people usually read newspaper. Tests were undertaken in 3 (three) repetitions to determine the effectiveness of ink (as a control) and two types of mosquito repellent inks that consisted of ink and citronella-clove leaf oil with ratio of 4:1 and 1:1 of substances that were presumed to have insect repellent qualities. The results of this study indicated that the mixture of newspaper ink and citronella-clove oil with ratio of 1:4 and 1:1 offer limited protection against mosquitoes bite in the range of 1-5 hours. The efficacy of the citronella-clove leaf oi mixture as mosquito repellent was between 75.85 to 91.10%. Hece, a blend of citronella and clove leaf oil could be added to printing ink and could be commercial potential as a short-period mosquito repellent. However, it is important in disseminating public health messages to emphasize the greater effectiveness of citronella and clove oils-based repellents ink in areas with risks of mosquito-borne disease.

  20. Taxonomy Icon Data: yellow fever mosquito [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available yellow fever mosquito Aedes aegypti Arthropoda Aedes_aegypti_L.png Aedes_aegypti_NL.png Aedes_aegypt...i_S.png Aedes_aegypti_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Aedes+aegypti...&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Aedes+aegypti&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Aedes+aegyp...ti&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Aedes+aegypti&t=NS ...

  1. “Where we put little fish in the water there are no mosquitoes:” a cross-sectional study on biological control of the Aedes aegypti vector in 90 coastal-region communities of Guerrero, Mexico

    Directory of Open Access Journals (Sweden)

    Arcadio Morales-Pérez

    2017-05-01

    Full Text Available Abstract Background In the Mexican state of Guerrero, some households place fish in water storage containers to prevent the development of mosquito larvae. Studies have shown that larvivorous fish reduce larva count in household water containers, but there is a lack of evidence about whether the use of fish is associated with a reduction in dengue virus infection. We used data from the follow up survey of the Camino Verde cluster randomised controlled trial of community mobilisation to reduce dengue risk to study this association. Methods The survey in 2012, among 90 clusters in the three coastal regions of Guerrero State, included a questionnaire to 10,864 households about socio-demographic factors and self-reported cases of dengue illness in the previous year. Paired saliva samples provided serological evidence of recent dengue infection among 4856 children aged 3–9 years. An entomological survey in the same households looked for larvae and pupae of Aedes aegypti and recorded presence of fish and temephos in water containers. We examined associations with the two outcomes of recent dengue infection and reported dengue illness in bivariate analysis and then multivariate analysis using generalized linear mixed modelling. Results Some 17% (1730/10,111 of households had fish in their water containers. The presence of fish was associated with lower levels of recent dengue virus infection in children aged 3–9 years (OR 0.64; 95% CI 0.45–0.91, as was living in a rural area (OR 0.57; 95% CI 0.45–0.71, and being aged 3–5 years (OR 0.65; 95% CI 0.51–0.83. Factors associated with lower likelihood of self-reported dengue illness were: the presence of fish (OR 0.79; 95% CI 0.64–0.97, and living in a rural area (OR 0.74; 95% CI 0.65–0.84. Factors associated with higher likelihood of self-reported dengue illness were: higher education level of the household head (OR 1.28; 95% CI 1.07–1.52, living in a household with five people or less

  2. De novo assembly and annotation of the Asian tiger mosquito (Aedes albopictus) repeatome with dnaPipeTE from raw genomic reads and comparative analysis with the yellow fever mosquito (Aedes aegypti).

    Science.gov (United States)

    Goubert, Clément; Modolo, Laurent; Vieira, Cristina; ValienteMoro, Claire; Mavingui, Patrick; Boulesteix, Matthieu

    2015-03-11

    Repetitive DNA, including transposable elements (TEs), is found throughout eukaryotic genomes. Annotating and assembling the "repeatome" during genome-wide analysis often poses a challenge. To address this problem, we present dnaPipeTE-a new bioinformatics pipeline that uses a sample of raw genomic reads. It produces precise estimates of repeated DNA content and TE consensus sequences, as well as the relative ages of TE families. We shows that dnaPipeTE performs well using very low coverage sequencing in different genomes, losing accuracy only with old TE families. We applied this pipeline to the genome of the Asian tiger mosquito Aedes albopictus, an invasive species of human health interest, for which the genome size is estimated to be over 1 Gbp. Using dnaPipeTE, we showed that this species harbors a large (50% of the genome) and potentially active repeatome with an overall TE class and order composition similar to that of Aedes aegypti, the yellow fever mosquito. However, intraorder dynamics show clear distinctions between the two species, with differences at the TE family level. Our pipeline's ability to manage the repeatome annotation problem will make it helpful for new or ongoing assembly projects, and our results will benefit future genomic studies of A. albopictus. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. Insecticidal activity of isobutylamides derived from Piper nigrum against adult of two mosquito species, Culex pipiens pallens and Aedes aegypti.

    Science.gov (United States)

    Park, Il-Kwon

    2012-01-01

    The insecticidal activity of Piper nigrum fruit-derived piperidine alkaloid (piperine) and N-isobutylamide alkaloids (pellitorine, guineensine, pipercide and retrofractamide A) against female adults of Culex pipiens pallens and Aedes aegypti was examined. On the basis of 24-h LD(50) values, the compound most toxic to female C. pipiens pallens was pellitorine (0.4 µg/♀) followed by guineensine (1.9 µg/♀), retrofractamide A (2.4 µg/♀) and pipercide (3.2 µg/♀). LD(50) value of chlorpyrifos was 0.03 µg/♀. Against female A. aegypti, the insecticidal activity was more pronounced in pellitorine (0.17 µg/♀) than in retrofractamide A (1.5 µg/♀), guineensine (1.7 µg/♀), and pipercide (2.0 µg/♀). LD(50) value of chlorpyrifos was 0.0014 µg/♀.

  4. Modulation of appetite and feeding behavior of the larval mosquito Aedes aegypti by the serotonin-selective reuptake inhibitor paroxetine: shifts between distinct feeding modes and the influence of feeding status.

    Science.gov (United States)

    Kinney, Michael P; Panting, Nicholas D; Clark, Thomas M

    2014-03-15

    The effects of the serotonin-selective reuptake inhibitor paroxetine (2×10(-5) mol l(-1)) on behavior of the larval mosquito Aedes aegypti are described. Four discrete behavioral states dominate larval behavior: wriggling, two distinct types of feeding, and quiescence. Feeding behaviors consist of foraging along the bottom of the container (substrate browsing), and stationary filter feeding while suspended from the surface film. Fed larvae respond to paroxetine with increased wriggling, and reductions in both feeding behaviors. In contrast, food-deprived larvae treated with paroxetine show no change in the proportion of time spent wriggling or feeding, but shift from stationary filter feeding to substrate browsing. Thus, actions of paroxetine in fed larvae are consistent with suppression of appetite and stimulation of wriggling, whereas paroxetine causes food-deprived larvae to switch from one feeding behavior to another. Further analysis of unfed larvae revealed that paroxetine decreased the power stroke frequency during wriggling locomotion, but had no effect on the swimming velocity during either wriggling or substrate browsing. These data suggest that: (1) serotonergic pathways may trigger shifts between distinct behaviors by actions on higher level (brain) integrating centers where behaviors such as feeding and locomotion are coordinated; (2) these centers in fed and food-deprived larvae respond differently to serotonergic stimulation suggesting sensory feedback from feeding status; and (3) serotonergic pathways also modulate central pattern generators of the nerve cord where the bursts of action potentials originate that drive the rhythmic muscle contractions of wriggling.

  5. Performance of the plant-based repellent TT-4302 against mosquitoes in the laboratory and field and comparative efficacy to 16 mosquito repellents against Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Bissinger, B W; Schmidt, J P; Owens, J J; Mitchell, S M; Kennedy, M K

    2014-03-01

    Repellent efficacy of the plant-based repellent, TT-4302 (5% geraniol), was compared with 16 other products in laboratory arm-in-cage trials against Aedes aegypti (L). Eight repellents (Badger, BioUD, Burt's bees, California Baby, Cutter Natural, EcoSMART, Herbal Armor, and SkinSmart) exhibited a mean repellency below 90% to Ae. aegypti at 0.5 h after application. Three repellents (Buzz Away Extreme, Cutter Advanced, and OFF! Botanicals lotion) fell below 90% repellency 1.5 h after application. TT-4302 exhibited 94.7% repellency 5 h posttreatment, which was a longer duration than any of the other repellents tested. The positive control, 15% DEET (OFF! Active), was repellent for 3 h before activity dropped below 90%. Additional arm-in-cage trials comparing TT-4302 with 15% DEET were carried out against Anopheles quadrimaculatus Say. At 6 h after treatment, TT-4302 provided 95.2% repellency while DEET exhibited 72.2%. In North Carolina field trials, TT-4302 provided 100% repellency 5 h after application against Aedes albopictus Skuse while DEET provided 77.6% repellency. These results demonstrate that TT-4302 is an efficacious plant-based repellent that provides an extended duration of protection compared with many other commercially available products.

  6. Genomic organization and splicing evolution of the doublesex gene, a Drosophila regulator of sexual differentiation, in the dengue and yellow fever mosquito Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Arcà Bruno

    2011-02-01

    Anopheles gambiae orthologue. In Aedes aegypti, the dsx gene is sex-specifically regulated and encodes two female-specific and one male-specific isoforms, all sharing a doublesex/mab-3 (DM domain-containing N-terminus and different C-termini. The sex-specific regulation is based on a combination of exon skipping, 5' alternative splice site choice and, most likely, alternative polyadenylation. Interestingly, when the Aeadsx gene is compared to the Anopheles dsx ortholog, there are differences in the in silico predicted default and regulated sex-specific splicing events, which suggests that the upstream regulators either are different or act in a slightly different manner. Furthermore, this study is a premise for the future development of transgenic sexing strains in mosquitoes useful for sterile insect technique (SIT programs.

  7. Genomic organization and splicing evolution of the doublesex gene, a Drosophila regulator of sexual differentiation, in the dengue and yellow fever mosquito Aedes aegypti

    Science.gov (United States)

    2011-01-01

    . In Aedes aegypti, the dsx gene is sex-specifically regulated and encodes two female-specific and one male-specific isoforms, all sharing a doublesex/mab-3 (DM) domain-containing N-terminus and different C-termini. The sex-specific regulation is based on a combination of exon skipping, 5' alternative splice site choice and, most likely, alternative polyadenylation. Interestingly, when the Aeadsx gene is compared to the Anopheles dsx ortholog, there are differences in the in silico predicted default and regulated sex-specific splicing events, which suggests that the upstream regulators either are different or act in a slightly different manner. Furthermore, this study is a premise for the future development of transgenic sexing strains in mosquitoes useful for sterile insect technique (SIT) programs. PMID:21310052

  8. Growth characteristics of the chimeric Japanese encephalitis virus vaccine candidate, ChimeriVax-JE (YF/JE SA14--14--2), in Culex tritaeniorhynchus, Aedes albopictus, and Aedes aegypti mosquitoes.

    Science.gov (United States)

    Bhatt, T R; Crabtree, M B; Guirakhoo, F; Monath, T P; Miller, B R

    2000-04-01

    The Japanese encephalitis (JE) virus vaccine candidate, ChimeriVax-JE, which consists of a yellow fever (YF) 17D virus backbone containing the prM and E genes from the JE vaccine strain JE SA14--14--2, exhibits restricted replication in non-human primates, producing only a low-level viremia following peripheral inoculation. Although this reduces the likelihood that hematophagous insects could become infected by feeding on a vaccinated host, it is prudent to investigate the replication kinetics of the vaccine virus in mosquito species that are known to vector the viruses from which the chimera is derived. In this study ChimeriVax-JE virus was compared to its parent viruses, as well as to wild-type JE virus, for its ability to replicate in Culex tritaeniorhynchus, Aedes albopictus, and Aedes aegypti mosquitoes. Individual mosquitoes were exposed to the viruses by oral ingestion of a virus-laden blood meal or by intrathoracic (IT) virus inoculation. ChimeriVax-JE virus did not replicate following ingestion by any of the three mosquito species. Additionally, replication was not detected after IT inoculation of ChimeriVax-JE in the primary JE virus vector, Cx. tritaeniorhynchus. ChimeriVax-JE exhibited moderate growth following IT inoculation into Ae. aegypti and Ae. albopictus, reaching titers of 3.6-5.0 log(10) PFU/mosquito. There was no change in the virus genotype associated with replication in mosquitoes. Similar results were observed in mosquitoes of all three species that were IT inoculated or had orally ingested the YF 17D vaccine virus. In contrast, all mosquitoes either IT inoculated with or orally fed wild-type and vaccine JE viruses became infected, reaching maximum titers of 5.4-7.3 log(10) PFU/mosquito. These results indicate that ChimeriVax-JE virus is restricted in its ability to infect and replicate in these mosquito vectors. The low viremia caused by ChimeriVax-JE in primates and poor infectivity for mosquitoes are safeguards against secondary spread

  9. Toxicity of compounds isolated from white snakeroot (Ageratina altissima) to adult and larval yellow fever mosquitoes (Aedes aegypti)

    Science.gov (United States)

    Because of increasing insecticide resistance, new pesticides are needed. Flowering plants have been the source of useful pesticides in the past. We studied 15 chemicals isolated from a poisonous pasture plant for activity against the yellow fever mosquito. We found that dehydrotremetone was effectiv...

  10. Bioassay-guided investigation of two monarda essential oils as repellents of yellow fever mosquito Aedes aegypti

    Science.gov (United States)

    As part of an ongoing research program to identify active mosquito repellents, Monarda bradburiana Beck and M. fistulosa L. essential oils showed potent repellents with minimum effective dosages (MED) of 0.055 ± 0.036 and 0.078 ± 0.027 mg/cm2, respectively, compared to reference standard N,N-diethyl...

  11. Role of an apical K,Cl cotransporter in urine formation by renal tubules of the yellow fever mosquito (Aedes aegypti).

    Science.gov (United States)

    Piermarini, Peter M; Hine, Rebecca M; Schepel, Matthew; Miyauchi, Jeremy; Beyenbach, Klaus W

    2011-11-01

    The K,Cl cotransporters (KCCs) of the SLC12 superfamily play critical roles in the regulation of cell volume, concentrations of intracellular Cl(-), and epithelial transport in vertebrate tissues. To date, the role(s) of KCCs in the renal functions of mosquitoes and other insects is less clear. In the present study, we sought molecular and functional evidence for the presence of a KCC in renal (Malpighian) tubules of the mosquito Aedes aegypti. Using RT-PCR on Aedes Malpighian tubules, we identified five alternatively spliced partial cDNAs that encode putative SLC12-like KCCs. The majority transcript is AeKCC1-A(1); its full-length cDNA was cloned. After expression of the AeKCC1-A protein in Xenopus oocytes, the Cl(-)-dependent uptake of (86)Rb(+) is 1) activated by 1 mM N-ethylmaleimide and cell swelling, 2) blocked by 100 μM dihydroindenyloxyalkanoic acid (DIOA), and 3) dependent upon N-glycosylation of AeKCC1-A. In Aedes Malpighian tubules, AeKCC1 immunoreactivity localizes to the apical brush border of principal cells, which are the predominant cell type in the epithelium. In vitro physiological assays of Malpighian tubules show that peritubular DIOA (10 μM): 1) significantly reduces both the control and diuretic rates of transepithelial fluid secretion and 2) has negligible effects on the membrane voltage and input resistance of principal cells. Taken together, the above observations indicate the presence of a KCC in the apical membrane of principal cells where it participates in a major electroneutral transport pathway for the transepithelial secretion of fluid in this highly electrogenic epithelium.

  12. How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus.

    Science.gov (United States)

    Yee, Donald A; Kaufman, Michael G; Ezeakacha, Nnaemeka F

    2015-01-01

    Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined development time, survival, and adult mass for males and females of three co-occurring species, Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus, across environments with different ratios of animal and leaf detritus. We quantified the contribution of detritus to biomass using stable isotope analysis and measured tissue carbon and nitrogen concentrations among species and between the sexes. Development times were shorter and adults were heavier for Aedes in animal versus leaf-only environments, whereas Culex development times were invariant across detritus types. Aedes displayed similar survival across detritus types whereas C. quinquefasciatus showed decreased survival with increasing leaf detritus. All species had lower values of 15N and 13C in leaf-only detritus compared to animal, however, Aedes generally had lower tissue nitrogen compared to C. quinquefasciatus. There were no differences in the C:N ratio between male and female Aedes, however, Aedes were different than C. quinquefasciatus adults, with male C. quinquefasciatus significantly higher than females. Culex quinquefasciatus was homeostatic across detrital environments. These results allow us to hypothesize an underlying stoichiometric explanation for the variation in performance of different container species under similar

  13. Determinasi Strain Aedes aegypti (Linn.) yang Rentan Homozigot dengan Metode Seleksi Indukan Tunggal

    OpenAIRE

    Isfanda Isfanda; Upik Kesumawati Hadi; Susi Soviana

    2017-01-01

    Abstract. Aedes aegypti is a type of mosquito that can carry dengue virus, yellow fever and chikunguya. The spread of this mosquito is very broad, covering almost all tropical regions worldwide. This study aims to determine the vulnerability status of homozygous Ae. aegypti. Sample of Ae. aegypti is mosquito strain from Health Entomology Laboratory Bogor Institute of Agriculture and at random sampling. Ae. aegypti eggs which comes from the breeders hatched separately. Insecticide‐treated pape...

  14. Rhamnolipids: solution against Aedes aegypti?

    Directory of Open Access Journals (Sweden)

    Vinicius Luiz Silva

    2015-02-01

    Full Text Available Aedes aegypti mosquitoes are the primary transmitters of dengue fever, urban yellow fever and chikungunya viruses. This mosquito has developed resistance to the insecticides currently used to control their populations. These chemical insecticides are harmful to the environment and can have negative effects on human health. Rhamnolipids are environmentally compatible biological surfactants, but their insecticidal activity has not been extensively studied. The present study evaluated the potential larvicidal, insecticidal and repellent activities of rhamnolipids against Aedes aegypti. At concentrations of 800, 900 and 1000 mg/L, rhamnolipids eliminated all mosquito larvae in 18 hours and killed 100% of adults at 1000 mg/L. According to the results it may be conclude that rhamnolipids should be applied to control larvae and mosquitos besides present the repellency activity against Aedes aegypti.

  15. No maternal effects after stimulation of the melanization response in the yellow fever mosquito Aedes aegypti

    OpenAIRE

    Voordouw, Maarten J.; Lambrechts, Louis; Koella, Jacob

    2011-01-01

    The costs and benefits of activating the immune system can reach across generations. Thus, in vertebrates and in several invertebrates, stimulating the immune system of a female can enhance immunity of her offspring or decrease offspring fitness. We evaluated the potential maternally transmitted costs and benefits of the melanization response, an innate immune response of insects that helps to protect mosquitoes from malaria parasites. We manipulated the maternal melanization response of the ...

  16. Taming a Tiger in the City: Comparison of Motorized Backpack Applications and Source Reduction Against the Asian Tiger Mosquito, Aedes albopictus

    Science.gov (United States)

    2014-06-01

    thuringiensis var. israelensis products assayed against Aedes aegypti (Diptera: Culicidae) in laboratory and outdoors at Rio de Janeiro , Brazil. Rev Inst...AEDES ALBOPICTUS 103 with a reasonable cost to large areas that would successfully impact mosquito populations . Larval mortality from backpack... populations . In conclusion, backpack applications of Bti are an effective and efficient control method against Ae. albopictus over large areas. This method

  17. Integrating the Public in Mosquito Management: Active Education by Community Peers Can Lead to Significant Reduction in Peridomestic Container Mosquito Habitats

    Science.gov (United States)

    Healy, Kristen; Hamilton, George; Crepeau, Taryn; Healy, Sean; Unlu, Isik; Farajollahi, Ary; Fonseca, Dina M.

    2014-01-01

    Mosquito species that utilize peridomestic containers for immature development are commonly aggressive human biters, and because they often reach high abundance, create significant nuisance. One of these species, the Asian tiger mosquito Aedes albopictus, is an important vector of emerging infectious diseases, such as dengue, chikungunya, and Zika fevers. Integrated mosquito management (IMM) of Ae. albopictus is particularly difficult because it requires access to private yards in urban and suburban residences. It has become apparent that in the event of a public health concern due to this species, homeowners will have to be active participants in the control process by reducing mosquito habitats in their properties, an activity known as source reduction. However, limited attempts at quantifying the effect of source reduction by homeowners have had mixed results. Of note, many mosquito control programs in the US have some form of education outreach, however the primary approach is often passive focusing on the distribution of education materials as flyers. In 2010, we evaluated the use of active community peer education in a source reduction program, using AmeriCorps volunteers. The volunteers were mobilized over a 4-week period, in two areas with approximately 1,000 residences each in urban Mercer and suburban Monmouth counties in New Jersey, USA. The volunteers were first provided training on peridomestic mosquitoes and on basic approaches to reducing the number of container habitats for mosquito larvae in backyards. Within the two treatment areas the volunteers successfully engaged 758 separate homes. Repeated measures analysis of variance showed a significant reduction in container habitats in the sites where the volunteers actively engaged the community compared to untreated control areas in both counties. Our results suggest that active education using community peer educators can be an effective means of source reduction, and a critical tool in the arsenal

  18. The Influence of Antibodies to Selected Mosquito Immunogens on Mosquitoes Following Ingestion of Blood from an Immune Vertebrate Host.

    Science.gov (United States)

    1992-08-05

    mosquito parts. Female Aedes aegypt ] (Rockefeller Strain) mosquitoes were used in this study. They were reared from eggs hatched In deoxygenated water... Aedes aegypti. We immunized mice with mosquito antigens prepared from sugar-fed and blood-fed mosquitoes as follows: heads and thoraces, abdomens, and...34 antigens on the life processes of Aedes aegypti. We have immunized mice with mosquito antigens prepared from both sugar-fed and blood-fed mosquitoes

  19. Feeding-induced changes in allatostatin-A and short neuropeptide F in the antennal lobes affect odor-mediated host seeking in the yellow fever mosquito, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Peter Christ

    Full Text Available Aedes aegypti is a model species in which the endogenous regulation of odor-mediated host seeking behavior has received some attention. Sugar feeding and host seeking in female A. aegypti are transiently inhibited following a blood meal. This inhibition is partially mediated by short neuropeptide F (sNPF. The paired antennal lobes (ALs, as the first processing centers for olfactory information, has been shown to play a significant role in the neuropeptidergic regulation of odor-mediated behaviors in insects. The expression of sNPF, along with other peptides in the ALs of A. aegypti, indicate parallel neuromodulatory systems that may affect olfactory processing. To identify neuropeptides involved in regulating the odor-mediated host seeking behavior in A. aegypti, we use a semi-quantitative neuropeptidomic analysis of single ALs to analyze changes in the levels of five individual neuropeptides in response to different feeding regimes. Our results show that the level of sNPF-2, allatostatin-A-5 (AstA-5 and neuropeptide-like precursor-1-5 (NPLP-1-5, but not of tachykinin-related-peptides and SIFamide (SIFa, in the AL of female mosquitoes, changes 24 h and 48 h post-blood meal, and are dependent on prior access to sugar. To assess the role of these neuropeptides in modulating host seeking behavior, when systemically injected individually, sNPF-2 and AstA-5 significantly reduced host seeking behavior. However, only the injection of the binary mixture of the two neuropeptides lead to a host seeking inhibition similar to that observed in blood fed females. We conclude that modulation of the odor mediated host seeking behavior of A. aegypti is likely regulated by a dual neuropeptidergic pathway acting in concert in the ALs.

  20. In silico models for predicting vector control chemicals targeting Aedes aegypti

    Science.gov (United States)

    Devillers, J.; Lagneau, C.; Lattes, A.; Garrigues, J.C.; Clémenté, M.M.; Yébakima, A.

    2014-01-01

    Human arboviral diseases have emerged or re-emerged in numerous countries worldwide due to a number of factors including the lack of progress in vaccine development, lack of drugs, insecticide resistance in mosquitoes, climate changes, societal behaviours, and economical constraints. Thus, Aedes aegypti is the main vector of the yellow fever and dengue fever flaviviruses and is also responsible for several recent outbreaks of the chikungunya alphavirus. As for the other mosquito species, the A. aegypti control relies heavily on the use of insecticides. However, because of increasing resistance to the different families of insecticides, reduction of Aedes populations is becoming increasingly difficult. Despite the unquestionable utility of insecticides in fighting mosquito populations, there are very few new insecticides developed and commercialized for vector control. This is because the high cost of the discovery of an insecticide is not counterbalanced by the ‘low profitability’ of the vector control market. Fortunately, the use of quantitative structure–activity relationship (QSAR) modelling allows the reduction of time and cost in the discovery of new chemical structures potentially active against mosquitoes. In this context, the goal of the present study was to review all the existing QSAR models on A. aegypti. The homology and pharmacophore models were also reviewed. Specific attention was paid to show the variety of targets investigated in Aedes in relation to the physiology and ecology of the mosquito as well as the diversity of the chemical structures which have been proposed, encompassing man-made and natural substances. PMID:25275884

  1. A SLC4-like anion exchanger from renal tubules of the mosquito (Aedes aegypti): evidence for a novel role of stellate cells in diuretic fluid secretion.

    Science.gov (United States)

    Piermarini, Peter M; Grogan, Laura F; Lau, Kenneth; Wang, Li; Beyenbach, Klaus W

    2010-03-01

    Transepithelial fluid secretion across the renal (Malpighian) tubule epithelium of the mosquito (Aedes aegypti) is energized by the vacuolar-type (V-type) H(+)-ATPase and not the Na(+)-K(+)-ATPase. Located at the apical membrane of principal cells, the V-type H(+)-ATPase translocates protons from the cytoplasm to the tubule lumen. Secreted protons are likely to derive from metabolic H(2)CO(3), which raises questions about the handling of HCO(3)(-) by principal cells. Accordingly, we tested the hypothesis that a Cl/HCO(3) anion exchanger (AE) related to the solute-linked carrier 4 (SLC4) superfamily mediates the extrusion of HCO(3)(-) across the basal membrane of principal cells. We began by cloning from Aedes Malpighian tubules a full-length cDNA encoding an SLC4-like AE, termed AeAE. When expressed heterologously in Xenopus oocytes, AeAE is both N- and O-glycosylated and mediates Na(+)-independent intracellular pH changes that are sensitive to extracellular Cl(-) concentration and to DIDS. In Aedes Malpighian tubules, AeAE is expressed as two distinct forms: one is O-glycosylated, and the other is N-glycosylated. Significantly, AeAE immunoreactivity localizes to the basal regions of stellate cells but not principal cells. Concentrations of DIDS that inhibit AeAE activity in Xenopus oocytes have no effects on the unstimulated rates of fluid secretion mediated by Malpighian tubules as measured by the Ramsay assay. However, in Malpighian tubules stimulated with kinin or calcitonin-like diuretic peptides, DIDS reduces the diuretic rates of fluid secretion to basal levels. In conclusion, Aedes Malpighian tubules express AeAE in the basal region of stellate cells, where this transporter may participate in producing diuretic rates of transepithelial fluid secretion.

  2. First report of Stegomyia aegypti (= Aedes aegypti) in Mexico City, Mexico.

    Science.gov (United States)

    Kuri-Morales, P; Correa-Morales, F; González-Acosta, C; Sánchez-Tejeda, G; Dávalos-Becerril, E; Fernanda Juárez-Franco, M; Díaz-Quiñonez, A; Huerta-Jimenéz, H; Mejía-Guevara, M D; Moreno-García, M; González-Roldán, J F

    2017-06-01

    Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is a species of mosquito that is currently widespread in Mexico. Historically, the mosquito has been distributed across most tropical and subtropical areas lower than 1700 m a.s.l. Currently, populations that are found at higher altitudes in regions with cold and dry climates suggest that these conditions do not limit the colonization and population growth of S. aegypti. During a survey of mosquitoes in September 2015, larvae of S. aegypti mosquitoes were found in two different localities in Mexico City, which is located at about 2250 m a.s.l. Mexico City is the most populous city in Mexico and has inefficient drainage and water supply systems. These factors may result in the provision of numerous larval breeding sites. Mosquito monitoring and surveillance are now priorities for the city. © 2017 The Royal Entomological Society.

  3. Behavioral responses of catnip (Nepeta cataria l.)by two species of mosquitoes, Aedes aegypti (l.) and Anopheles harrisoni harbach and manguin, in Thailand.

    Science.gov (United States)

    An investigation of the biological effect of catnip oil (Nepeta cataria L.) on the behavioral response of field collected Ae. aegypti and An. harrisoni were conducted using an automated excito-repellency test system. Aedes aegypti showed significant higher escape rates from the contact chamber at 5%...

  4. Development and Evaluation of a Pyriproxyfen-treated Device to Control the Dengue Vector, Aedes aegypti (L.) (Diptera: Culicidae)

    Science.gov (United States)

    2013-03-01

    that is visually- attractive to mosquitoes. This pyriproxyfen-treated device was evaluated for its impact on Ae. aegypti egg production and population... attractive as a resting station to mosquitoes of all physiological stages. The results show this device suppressed Ae. aegypti popula- tions after it was...aegypti control device that is visually- attractive to mosquitoes. This pyriproxyfen-treated device was evaluated for its impact on Ae. aegypti egg

  5. Larvicidal activity of ajowan ( Trachyspermum ammi ) and Peru balsam ( Myroxylon pereira ) oils and blends of their constituents against mosquito, Aedes aegypti , acute toxicity on water flea, Daphnia magna , and aqueous residue.

    Science.gov (United States)

    Seo, Seon-Mi; Park, Hye-Mi; Park, Il-Kwon

    2012-06-13

    This study evaluated the larvicidal activity of 20 plant essential oils and components from ajowan ( Trachyspermum ammi ) and Peru balsam ( Myroxylon pereira ) oils against the mosquito, Aedes aegypti . Of the 20 plant essential oils, ajowan and Peru balsam oils at 0.1 mg/mL exhibited 100 and 97.5% larval mortality, respectively. At this same concentration, the individual constituents, (+)-camphene, benzoic acid, thymol, carvacrol, benzyl benzonate, and benzyl trans-cinnamate, caused 100% mortality. The toxicity of blends of constituents identified in two active oils indicated that thymol and benzyl benzoate were major contributors to the larvicidal activity of the artificial blend. This study also tested the acute toxicity of these two active oils and their major constituents against the water flea, Daphnia magna . Peru balsam oil and benzyl trans-cinnamate were the most toxic to D. magna. Two days after the treatment, residues of ajowan and Peru balsalm oils in water were 36.2 and 85.1%, respectively. Less than 50% of benzyl trans-cinnamate and thymol were detected in the water at 2 days after treatment. The results show that the essential oils of ajowan and Peru balsam and some of their constituents have potential as botanical insecticides against Ae. aegypti mosquito larvae.

  6. Infestação pelo mosquito Aedes aegypti (Diptera: Culicidae na cidade de Chapecó – SC

    Directory of Open Access Journals (Sweden)

    Junir Antonio Lutinski

    2013-03-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n2p143   A dengue se tornou um problema de saúde pública e vem causando preocupação aos profissionais de saúde. Este estudo visou a avaliar os fatores condicionantes para a ocorrência de dengue na cidade de Chapecó – SC. Foram analisadas as informações disponíveis no Sistema de Informações de Febre Amarela e Dengue (SISFAD e foi realizada uma pesquisa a partir de um questionário semiestruturado aplicado à população. As análises indicam a associação da infestação pelo mosquito transmissor da dengue com o lixo inadequadamente tratado e com os depósitos de captação de água da chuva, assim como com o ambiente residencial. A prevenção à dengue no município de Chapecó envolve a implantação de políticas públicas de educação ambiental em saúde para a separação e destinação adequada dos resíduos sólidos e melhorias no sistema de abastecimento público de água. Campanhas educativas voltadas aos cuidados no ambiente domiciliar também são necessárias.

  7. UV-B radiation reduces in vitro germination of Metarhizium anisopliae s.l. but does not affect virulence in fungus-treated Aedes aegypti adults and development on dead mosquitoes.

    Science.gov (United States)

    Falvo, M L; Pereira-Junior, R A; Rodrigues, J; López Lastra, C C; García, J J; Fernandes, É K K; Luz, C

    2016-12-01

    Control of diurnal Aedes aegypti with mycoinsecticides should consider the exposure of fungus-treated adults to sunlight, and especially to UV-B radiation that might affect activity of conidia applied on the mosquito's surface. Germination of Metarhizium anisopliae s.l. IP 46 conidia on SDAY medium was not affected at the lowest level of radiation with UV-B, 0·69 kJ m -2 , but was retarded and reduced at higher 2·075 and 4·15 kJ m -2 , and completely inhibited at ≥8·3 kJ m -2 . In contrast, germination of conidia applied onto fibreglass nettings and exposed from 0 to 16·6 kJ m -2 did not differ significantly among levels of irradiance exposure and the controls. There was also no significant impact of UV-B up to 16·6 kJ m -2 on the adulticidal activity of IP 46 and on the subsequent conidiogenesis on cadavers. The Quaite-weighted UV-B irradiance in the laboratory (1152 mW m -2 ) was higher than the natural sunlight irradiance observed in the city of Goiânia in Central Brazil on midday (706 mW m -2 in August to 911 mW m -2 in October 2015). UV-B does not impair the activity of IP 46 conidia applied previously to radiation on A. aegypti adults. Findings contribute to a better understanding of the effectiveness of M. anisopliae against day-active A. aegypti and its potential for biological mosquito control. © 2016 The Society for Applied Microbiology.

  8. Identification of Aedes aegypti and Its Respective Life Stages by Real-Time Polymerase Chain Reaction

    National Research Council Canada - National Science Library

    McAvin, James C; Bowles, David E; Swaby, James A; Blount, Keith W; Blow, Jamie A; Quintana, Miguel; Hickman, John R; Atchley, Daniel H; Niemeyer, Debra M

    2004-01-01

    .... Laboratory-based testing of A. aegypti, A. aegypti (Trinidad strain), Culex pipiens, Culex quinquefasciatus, Anopheles stephensi, and Ochlerotatus taeniorhynchus individual adult mosquitoes and mixed pools (n = 10) demonstrated 100...

  9. Light Color Attraction and Dietary Sugar Composition for Several Mosquito (Diptera: Culicidae) Species Found in North Central Florida

    Science.gov (United States)

    1998-07-02

    S. R. 1960. Aedes aegypti. the yellow fever Mosquito. Cambridge University Press, Cambrdge. Clements, A. N. 1992. The Biology of Mosquitoes. Vol. 1...Materials 76 Results 78 Discussion 80 6. LABORATORY EVALUATION OF COLORED LIGHT AS AN ATTRACTANT FOR FEMALE AEDES AEGYPTI, AEDES ALBOPICTUS ...Light Source and Filters 90 Mosquito Species 90 Statistical Analysis 91 Results 91 Aedes aegypti 92 Aedes albopictus 92 Anopheles

  10. Microevolution of Aedes aegypti.

    Science.gov (United States)

    Louise, Caroline; Vidal, Paloma Oliveira; Suesdek, Lincoln

    2015-01-01

    Scientific research into the epidemiology of dengue frequently focuses on the microevolution and dispersion of the mosquito Aedes aegypti. One of the world's largest urban agglomerations infested by Ae. aegypti is the Brazilian megalopolis of Sao Paulo, where >26,900 cases of dengue were reported until June 2015. Unfortunately, the dynamics of the genetic variability of Ae. aegypti in the Sao Paulo area have not been well studied. To reduce this knowledge gap, we assessed the morphogenetic variability of a population of Ae. aegypti from a densely urbanised neighbourhood of Sao Paulo. We tested if allelic patterns could vary over a short term and if wing shape could be a predictor of the genetic variation. Over a period of 14 months, we examined the variation of genetic (microsatellites loci) and morphological (wing geometry) markers in Ae. aegypti. Polymorphisms were detected, as revealed by the variability of 20 microsatellite loci (115 alleles combined; overall Fst = 0.0358) and 18 wing landmarks (quantitative estimator Qst = 0.4732). These levels of polymorphism are higher than typically expected to an exotic species. Allelic frequencies of the loci changed over time and temporal variation in the wing shape was even more pronounced, permitting high reclassification levels of chronological samples. In spite of the fact that both markers underwent temporal variation, no correlation was detected between their dynamics. We concluded that microevolution was detected despite the short observational period, but the intensities of change of the markers were discrepant. Wing shape failed from predicting allelic temporal variation. Possibly, natural selection (Qst>Fst) or variance of expressivity of wing phenotype are involved in this discrepancy. Other possibly influential factors on microevolution of Ae. aegypti are worth searching. Additionally, the implications of the rapid evolution and high polymorphism of this mosquito vector on the efficacy of control methods have

  11. Microevolution of Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Caroline Louise

    Full Text Available Scientific research into the epidemiology of dengue frequently focuses on the microevolution and dispersion of the mosquito Aedes aegypti. One of the world's largest urban agglomerations infested by Ae. aegypti is the Brazilian megalopolis of Sao Paulo, where >26,900 cases of dengue were reported until June 2015. Unfortunately, the dynamics of the genetic variability of Ae. aegypti in the Sao Paulo area have not been well studied. To reduce this knowledge gap, we assessed the morphogenetic variability of a population of Ae. aegypti from a densely urbanised neighbourhood of Sao Paulo. We tested if allelic patterns could vary over a short term and if wing shape could be a predictor of the genetic variation. Over a period of 14 months, we examined the variation of genetic (microsatellites loci and morphological (wing geometry markers in Ae. aegypti. Polymorphisms were detected, as revealed by the variability of 20 microsatellite loci (115 alleles combined; overall Fst = 0.0358 and 18 wing landmarks (quantitative estimator Qst = 0.4732. These levels of polymorphism are higher than typically expected to an exotic species. Allelic frequencies of the loci changed over time and temporal variation in the wing shape was even more pronounced, permitting high reclassification levels of chronological samples. In spite of the fact that both markers underwent temporal variation, no correlation was detected between their dynamics. We concluded that microevolution was detected despite the short observational period, but the intensities of change of the markers were discrepant. Wing shape failed from predicting allelic temporal variation. Possibly, natural selection (Qst>Fst or variance of expressivity of wing phenotype are involved in this discrepancy. Other possibly influential factors on microevolution of Ae. aegypti are worth searching. Additionally, the implications of the rapid evolution and high polymorphism of this mosquito vector on the efficacy of

  12. A Large Scale Biorational Approach Using Bacillus thuringiensis israeliensis (Strain AM65-52 for Managing Aedes aegypti Populations to Prevent Dengue, Chikungunya and Zika Transmission.

    Directory of Open Access Journals (Sweden)

    Catherine A Pruszynski

    Full Text Available Aedes aegypti is a container-inhabiting mosquito and a vector of dengue, chikungunya, and Zika viruses. In 2009 several cases of autochthonous dengue transmission were reported in Key West, Florida, USA prompting a comprehensive response to control A. aegypti. In Key West, larvae of this mosquito develop in containers around human habitations which can be numerous and labor intensive to find and treat. Aerial applications of larvicide covering large areas in a short time can be an efficient and economical method to control A. aegypti. Bacillus thuringiensis israelensis (Bti is a bacterial larvicide which is highly target specific and appropriate for wide area spraying over urban areas, but to date, there are no studies that evaluate aerial spraying of Bti to control container mosquitoes like A. aegypti.This paper examines the effectiveness of aerial larvicide applications using VectoBac® WG, a commercially available Bti formulation, for A. aegypti control in an urban setting in the USA. Droplet characteristics and spray drop deposition were evaluated in Key West, Florida, USA. The mortality of A. aegypti in containers placed under canopy in an urban environment was also evaluated. Efficacy of multiple larvicide applications on adult female A. aegypti population reduction was compared between an untreated control and treatment site.Droplet characteristics showed that small droplets can penetrate through dense canopy to reach small containers. VectoBac WG droplets reached small containers under heavy canopy in sufficient amounts to cause > 55% mortality on all application days and >90% mortality on 3 of 5 application days while controls had 50%. Aerial larvicide applications using VectoBac WG can cover wide areas in a short period of time and can be effective in controlling A. aegypti and reducing A. aegypti-borne transmission in urban areas similar to Key West, Florida, USA.

  13. A Large Scale Biorational Approach Using Bacillus thuringiensis israeliensis (Strain AM65-52) for Managing Aedes aegypti Populations to Prevent Dengue, Chikungunya and Zika Transmission.

    Science.gov (United States)

    Pruszynski, Catherine A; Hribar, Lawrence J; Mickle, Robert; Leal, Andrea L

    2017-01-01

    Aedes aegypti is a container-inhabiting mosquito and a vector of dengue, chikungunya, and Zika viruses. In 2009 several cases of autochthonous dengue transmission were reported in Key West, Florida, USA prompting a comprehensive response to control A. aegypti. In Key West, larvae of this mosquito develop in containers around human habitations which can be numerous and labor intensive to find and treat. Aerial applications of larvicide covering large areas in a short time can be an efficient and economical method to control A. aegypti. Bacillus thuringiensis israelensis (Bti) is a bacterial larvicide which is highly target specific and appropriate for wide area spraying over urban areas, but to date, there are no studies that evaluate aerial spraying of Bti to control container mosquitoes like A. aegypti. This paper examines the effectiveness of aerial larvicide applications using VectoBac® WG, a commercially available Bti formulation, for A. aegypti control in an urban setting in the USA. Droplet characteristics and spray drop deposition were evaluated in Key West, Florida, USA. The mortality of A. aegypti in containers placed under canopy in an urban environment was also evaluated. Efficacy of multiple larvicide applications on adult female A. aegypti population reduction was compared between an untreated control and treatment site. Droplet characteristics showed that small droplets can penetrate through dense canopy to reach small containers. VectoBac WG droplets reached small containers under heavy canopy in sufficient amounts to cause > 55% mortality on all application days and >90% mortality on 3 of 5 application days while controls had treated sites was >50%. Aerial larvicide applications using VectoBac WG can cover wide areas in a short period of time and can be effective in controlling A. aegypti and reducing A. aegypti-borne transmission in urban areas similar to Key West, Florida, USA.

  14. Repelling mosquitoes with essential oils

    Science.gov (United States)

    Riley, L.

    2017-12-01

    Mosquitoes carry diseases than can lead to serious illness and death. According to the World Health Organization, mosquitoes infect over 300 million people a year with Malaria and Dengue Fever, two life threatening diseases vectored by mosquitoes. Although insecticides are the most effective way to control mosquitoes, they are not always environmentally friendly. Therefore, alternative tactics should be considered. In this study, we looked at the repellency of various essential oils on female Aedes aegypti through a series of laboratory assays.

  15. Transmission risk of two chikungunya lineages by invasive mosquito vectors from Florida and the Dominican Republic

    Science.gov (United States)

    Wiggins, Keenan; Eastmond, Bradley; Velez, Daniel; Lounibos, L. Philip; Lord, Cynthia C.

    2017-01-01

    Between 2014 and 2016 more than 3,800 imported human cases of chikungunya fever in Florida highlight the high risk for local transmission. To examine the potential for sustained local transmission of chikungunya virus (CHIKV) in Florida we tested whether local populations of Aedes aegypti and Aedes albopictus show differences in susceptibility to infection and transmission to two emergent lineages of CHIKV, Indian Ocean (IOC) and Asian genotypes (AC) in laboratory experiments. All examined populations of Ae. aegypti and Ae. albopictus mosquitoes displayed susceptibility to infection, rapid viral dissemination into the hemocoel, and transmission for both emergent lineages of CHIKV. Aedes albopictus had higher disseminated infection and transmission of IOC sooner after ingesting CHIKV infected blood than Ae. aegypti. Aedes aegypti had higher disseminated infection and transmission later during infection with AC than Ae. albopictus. Viral dissemination and transmission of AC declined during the extrinsic incubation period, suggesting that transmission risk declines with length of infection. Interestingly, the reduction in transmission of AC was less in Ae. aegypti than Ae. albopictus, suggesting that older Ae. aegypti females are relatively more competent vectors than similar aged Ae. albopictus females. Aedes aegypti originating from the Dominican Republic had viral dissemination and transmission rates for IOC and AC strains that were lower than for Florida vectors. We identified small-scale geographic variation in vector competence among Ae. aegypti and Ae. albopictus that may contribute to regional differences in risk of CHIKV transmission in Florida. PMID:28749964

  16. Surveillance and Spatial Characterization of Aedes aegypti in Sint Eustatius, Netherlands Antilles

    Science.gov (United States)

    2013-05-08

    attractant traps to reduce mosquito biting (56). AEDES AEGYPTI Aedes aegypti, known commonly as the yellow fever mosquito, is a vector for several...DENV), yellow fever virus (YFV), West Nile virus (WNV), and tick-borne encephalitis virus (TBEV) among other encephalitic viruses. Most of the...primarily by the urbanized Ae. aegypti and peridomestic Ae. albopictus . Aedes aegypti is the primary vector implicated for dengue transmission and Ae

  17. Isolation and identification of mosquito (Aedes aegypti) biting deterrent fatty acids from male inflorescences of breadfruit (Artocarpus altilis (Parkinson)Fosberg)

    Science.gov (United States)

    Dried male inflorescences of breadfruit (Artocarpus altilis, Moraceae) are burned in communities throughout Oceania to repel flying insects, including mosquitoes. This study was conducted to identify chemicals responsible for mosquito deterrence. Various crude extracts were evaluated, and the most a...

  18. Age-dependent effects of oral infection with dengue virus on Aedes aegypti (Diptera: Culicidae) feeding behavior, survival, oviposition success and fecundity.

    Science.gov (United States)

    Sylvestre, Gabriel; Gandini, Mariana; Maciel-de-Freitas, Rafael

    2013-01-01

    Aedes aegypti is the main vector of dengue, a disease that is increasing its geographical range as well as incidence rates. Despite its public health importance, the effect of dengue virus (DENV) on some mosquito traits remains unknown. Here, we investigated the impact of DENV-2 infection on the feeding behavior, survival, oviposition success and fecundity of Ae. aegypti females. After orally-challenging Ae. aegypti females with a DENV-2 strain using a membrane feeder, we monitored the feeding behavior, survival, oviposition success and fecundity throughout the mosquito lifespan. We observed an age-dependent cost of DENV infection on mosquito feeding behavior and fecundity. Infected individuals took more time to ingest blood from anesthetized mice in the 2(nd) and 3(rd) weeks post-infection, and also longer overall blood-feeding times in the 3(rd) week post-infection, when females were around 20 days old. Often, infected Ae. aegypti females did not lay eggs and when they were laid, smaller number of eggs were laid compared to uninfected controls. A reduction in the number of eggs laid per female was evident starting on the 3(rd) week post-infection. DENV-2 negatively affected mosquito lifespan, since overall the longevity of infected females was halved compared to that of the uninfected control group. The DENV-2 strain tested significantly affected Ae. aegypti traits directly correlated with vectorial capacity or mosquito population density, such as feeding behavior, survival, fecundity and oviposition success. Infected mosquitoes spent more time ingesting blood, had reduced lifespan, laid eggs less frequently, and when they did lay eggs, the clutches were smaller than uninfected mosquitoes.

  19. Age-dependent effects of oral infection with dengue virus on Aedes aegypti (Diptera: Culicidae feeding behavior, survival, oviposition success and fecundity.

    Directory of Open Access Journals (Sweden)

    Gabriel Sylvestre

    Full Text Available BACKGROUND: Aedes aegypti is the main vector of dengue, a disease that is increasing its geographical range as well as incidence rates. Despite its public health importance, the effect of dengue virus (DENV on some mosquito traits remains unknown. Here, we investigated the impact of DENV-2 infection on the feeding behavior, survival, oviposition success and fecundity of Ae. aegypti females. METHODS/PRINCIPAL FINDINGS: After orally-challenging Ae. aegypti females with a DENV-2 strain using a membrane feeder, we monitored the feeding behavior, survival, oviposition success and fecundity throughout the mosquito lifespan. We observed an age-dependent cost of DENV infection on mosquito feeding behavior and fecundity. Infected individuals took more time to ingest blood from anesthetized mice in the 2(nd and 3(rd weeks post-infection, and also longer overall blood-feeding times in the 3(rd week post-infection, when females were around 20 days old. Often, infected Ae. aegypti females did not lay eggs and when they were laid, smaller number of eggs were laid compared to uninfected controls. A reduction in the number of eggs laid per female was evident starting on the 3(rd week post-infection. DENV-2 negatively affected mosquito lifespan, since overall the longevity of infected females was halved compared to that of the uninfected control group. CONCLUSIONS: The DENV-2 strain tested significantly affected Ae. aegypti traits directly correlated with vectorial capacity or mosquito population density, such as feeding behavior, survival, fecundity and oviposition success. Infected mosquitoes spent more time ingesting blood, had reduced lifespan, laid eggs less frequently, and when they did lay eggs, the clutches were smaller than uninfected mosquitoes.

  20. A neuron-specific antiviral mechanism prevents lethal flaviviral infection of mosquitoes.

    Science.gov (United States)

    Xiao, Xiaoping; Zhang, Rudian; Pang, Xiaojing; Liang, Guodong; Wang, Penghua; Cheng, Gong

    2015-04-01

    Mosquitoes are natural vectors for many etiologic agents of human viral diseases. Mosquito-borne flaviviruses can persistently infect the mosquito central nervous system without causing dramatic pathology or influencing the mosquito behavior and lifespan. The mechanism by which the mosquito nervous system resists flaviviral infection is still largely unknown. Here we report that an Aedes aegypti homologue of the neural factor Hikaru genki (AaHig) efficiently restricts flavivirus infection of the central nervous system. AaHig was predominantly expressed in the mosquito nervous system and localized to the plasma membrane of neural cells. Functional blockade of AaHig enhanced Dengue virus (DENV) and Japanese encephalitis virus (JEV), but not Sindbis virus (SINV), replication in mosquito heads and consequently caused neural apoptosis and a dramatic reduction in the mosquito lifespan. Consistently, delivery of recombinant AaHig to mosquitoes reduced viral infection. Furthermore, the membrane-localized AaHig directly interfaced with a highly conserved motif in the surface envelope proteins of DENV and JEV, and consequently interrupted endocytic viral entry into mosquito cells. Loss of either plasma membrane targeting or virion-binding ability rendered AaHig nonfunctional. Interestingly, Culex pipien pallens Hig also demonstrated a prominent anti-flavivirus activity, suggesting a functionally conserved function for Hig. Our results demonstrate that an evolutionarily conserved antiviral mechanism prevents lethal flaviviral infection of the central nervous system in mosquitoes, and thus may facilitate flaviviral transmission in nature.

  1. Dopamine levels in the mosquito Aedes aegypti  during adult development, following blood feeding and in response to heat stress

    DEFF Research Database (Denmark)

    Andersen, Janne Pleidrup; Schwartz, Alex Mark; Gramsbergen, J.B.

    2006-01-01

    Dopamine, a catecholamine neurotransmitter, is important for insect development and is known to be involved in insect stress responses. In the current study, dopamine was analysed in Aedes aegypti heads by HPLC. We found that immediately after adult emergence, males have significantly higher...

  2. Toksisitas Insektisida Organofosfat Dan Karbamat Terhadap Nyamuk Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Endang Puji Astuti

    2013-02-01

    Full Text Available Abstract. Aedes aegypti mosquito is increasing problem of public health, being the vector responsible for Dengue and Chikungunya. Chlorpirifos (Organofosfat and Metonil (Carbamate were known to posses insecticide activity against insect. The study was aimed to examine effectiveness of Chlorpirifos and Metonil as insectiside against Ae. aegypti mos­quito Chlorpirifos a significantly higher insecticide activity against Ae. aegypti_than Metonil. The mosquito mortality was observed after 24 h exposure. The LCso value of Chlor­pirifos and Metonil were 0.64 mg/lt and 0,802 mg/lt, against Ae. aegypti mosquito. The mixed of both insecticide was LCso value 108.04 mg/lt, this result prove that mixed of both insecticede not sinergism. The result of th is study suggested that Chlorpirifos more effective insecticide against Ae. aegypti than Metonil. Key Words : Culex quinquefasciatus, insecticide, chlorpirifos, metonil

  3. Radiation cytogenetics of the yellow-fever mosquito Aedes aegypti and the plant genus Collinsia. Final report, April 1967--September 1977

    International Nuclear Information System (INIS)

    Rai, K.S.

    1977-01-01

    The major objectives of the project on Aedes aegypti, which is one of the most important disease vectors of man, were to study the cytogenetic effects of radiation and certain chemical mutagens, the genetics of radiation-induced chromosomal rearrangements with particular attention to reciprocal translocations, and the possibility of using translocations for genetic control of natural populations. Results reported on work done during the years 1967 and 1977 show these objectives have been mostly accomplished

  4. Radiation cytogentics of the yellow-fever mosquito Aedes aegypti and the plant genus Collinsia. Final report, April 1967--September 1977

    Energy Technology Data Exchange (ETDEWEB)

    Rai, K.S.

    1977-01-01

    The major objectives of the project on Aedes aegypti, which is one of the most important disease vectors of man, were to study the cytogenetic effects of radiation and certain chemical mutagens, the genetics of radiation-induced chromosomal rearrangements with particular attention to reciprocal translocations, and the possibility of using translocations for genetic control of natural populations. Results reported on work done during the years 1967 and 1977 show these objectives have been mostly accomplished.

  5. Larvicidal Potential of the Halogenated Sesquiterpene (+)-Obtusol, Isolated from the Alga Laurencia dendroidea J. Agardh (Ceramiales: Rhodomelaceae), against the Dengue Vector Mosquito Aedes aegypti (Linnaeus) (Diptera: Culicidae)

    Science.gov (United States)

    Salvador-Neto, Orlando; Gomes, Simone Azevedo; Soares, Angélica Ribeiro; Machado, Fernanda Lacerda da Silva; Samuels, Richard Ian; Nunes da Fonseca, Rodrigo; Souza-Menezes, Jackson; Moraes, Jorge Luiz da Cunha; Campos, Eldo; Mury, Flávia Borges; Silva, José Roberto

    2016-01-01

    Dengue is considered a serious public health problem in many tropical regions of the world including Brazil. At the moment, there is no viable alternative to reduce dengue infections other than controlling the insect vector, Aedes aegypti Linnaeus. In the continuing search for new sources of chemicals targeted at vector control, natural products are a promising alternative to synthetic pesticides. In our work, we investigated the toxicity of a bioactive compound extracted from the red alga Laurencia dendroidea J. Agardh. The initial results demonstrated that crude extracts, at a concentration of 5 ppm, caused pronounced mortality of second instar A. aegypti larvae. Two molecules, identified as (−)-elatol and (+)-obtusol were subsequently isolated from crude extract and further evaluated. Assays with (−)-elatol showed moderate larvicidal activity, whereas (+)-obtusol presented higher toxic activity than (−)-elatol, with a LC50 value of 3.5 ppm. Histological analysis of the larvae exposed to (+)-obtusol revealed damage to the intestinal epithelium. Moreover, (+)-obtusol-treated larvae incubated with 2 µM CM-H2DCFDA showed the presence of reactive oxygen species, leading us to suggest that epithelial damage might be related to redox imbalance. These results demonstrate the potential of (+)-obtusol as a larvicide for use against A. aegypti and the possible mode of action of this compound. PMID:26821032

  6. Glytube: a conical tube and parafilm M-based method as a simplified device to artificially blood-feed the dengue vector mosquito, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    André Luis Costa-da-Silva

    Full Text Available Aedes aegypti, the main vector of dengue virus, requires a blood meal to produce eggs. Although live animals are still the main blood source for laboratory colonies, many artificial feeders are available. These feeders are also the best method for experimental oral infection of Ae. aegypti with Dengue viruses. However, most of them are expensive or laborious to construct. Based on principle of Rutledge-type feeder, a conventional conical tube, glycerol and Parafilm-M were used to develop a simple in-house feeder device. The blood feeding efficiency of this apparatus was compared to a live blood source, mice, and no significant differences (p = 0.1189 were observed between artificial-fed (51.3% of engorgement and mice-fed groups (40.6%. Thus, an easy to assemble and cost-effective artificial feeder, designated "Glytube" was developed in this report. This simple and efficient feeding device can be built with common laboratory materials for research on Ae. aegypti.

  7. Sindbis virus infection alters blood feeding responses and DEET repellency in Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Qualls, Whitney A; Day, Jonathan F; Xue, Rui-De; Bowers, Doria F

    2012-03-01

    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.

  8. Filarial worms reduce Plasmodium infectivity in mosquitoes.

    Directory of Open Access Journals (Sweden)

    Matthew T Aliota

    2011-02-01

    Full Text Available Co-occurrence of malaria and filarial worm parasites has been reported, but little is known about the interaction between filarial worm and malaria parasites with the same Anopheles vector. Herein, we present data evaluating the interaction between Wuchereria bancrofti and Anopheles punctulatus in Papua New Guinea (PNG. Our field studies in PNG demonstrated that An. punctulatus utilizes the melanization immune response as a natural mechanism of filarial worm resistance against invading W. bancrofti microfilariae. We then conducted laboratory studies utilizing the mosquitoes Armigeres subalbatus and Aedes aegypti and the parasites Brugia malayi, Brugia pahangi, Dirofilaria immitis, and Plasmodium gallinaceum to evaluate the hypothesis that immune activation and/or development by filarial worms negatively impact Plasmodium development in co-infected mosquitoes. Ar. subalbatus used in this study are natural vectors of P. gallinaceum and B. pahangi and they are naturally refractory to B. malayi (melanization-based refractoriness.Mosquitoes were dissected and Plasmodium development was analyzed six days after blood feeding on either P. gallinaceum alone or after taking a bloodmeal containing both P. gallinaceum and B. malayi or a bloodmeal containing both P. gallinaceum and B. pahangi. There was a significant reduction in the prevalence and mean intensity of Plasmodium infections in two species of mosquito that had dual infections as compared to those mosquitoes that were infected with Plasmodium alone, and was independent of whether the mosquito had a melanization immune response to the filarial worm or not. However, there was no reduction in Plasmodium development when filarial worms were present in the bloodmeal (D. immitis but midgut penetration was absent, suggesting that factors associated with penetration of the midgut by filarial worms likely are responsible for the observed reduction in malaria parasite infections.These results could have an

  9. TESTE DA CORRELAÇÃO ENTRE HIPSOMETRIA E ÍNDICES DE OCORRÊNCIA DO MOSQUITO AEDES AEGYPTI NA CIDADE DE MONTES CLAROS-MG COM DADOS DOS ANOS 2009 E 2010

    Directory of Open Access Journals (Sweden)

    Cynara Kaliny Ribeiro Braz

    2013-10-01

    Full Text Available O objetivo deste trabalho é espacializar os focos de ocorrência do mosquito Aedes aegypti, com dados dos anos 2009 e 2010 do Índice de Infestação Predial da cidade de Montes Claros e apontar os bairros que têm tido maior predisposição à ocorrência do vetor da Dengue. A metodologia empregada consistiu na montagem de um banco de dados georreferenciado contendo uma tabela de atributos com informações do índice de infestação, a partir de informações fornecidas pela Prefeitura Municipal de Montes Claros e o cruzamento dessas com dados do Shuttle Radar Topography Mission (SRTM. Os resultados mostram que houve crescimento significativo no índice de infestação predial entre os anos 2009 (com média de 2,66% e 2010 (com média de 3,2%. As informações evidenciam que existe associação entre os dados do índice dos anos analisados, o que pode sugerir a propensão a resultados similares nos anos seguintes caso não sejam tomadas ações mitigadoras. As áreas críticas são principalmente aquelas de maior aglomeração urbana, posicionadas na região central. Os resultados mostram ainda que não existiu correlação alguma entre a altitude dos bairros e a ocorrência do mosquito transmissor da Dengue.

  10. IDENTIFIKASI AEDES AEGYPTI DAN AEDES ALBOPICTUS

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    Diah Fitri Rahayu

    2013-09-01

    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

  11. Burchellin: study of bioactivity against Aedes aegypti

    OpenAIRE

    Narciso, Juliana Oliveira Abreu; Soares, Renata Oliveira de Araújo; Reis dos Santos Mallet, Jacenir; Guimarães, Anthony Érico; de Oliveira Chaves, Maria Célia; Barbosa-Filho, José Maria; Maleck, Marise

    2014-01-01

    Background The dengue mosquito Aedes aegypti Linnaeus, 1762 is a widespread insect pest of serious medical importance. Since no effective vaccine is available for treating dengue, the eradication or control of the main mosquito vector is regarded as essential. Since conventional insecticides have limited success, plants may be an alternative source of larvicidal agents, since they contain a rich source of bioactive chemicals. The aim of this study was to evaluate the larvicidal activity of th...

  12. Microsporidiosis (Microsporidia: Culicosporidae) alters blood-feeding responses and DEET repellency in Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Barnard, Donald R; Xue, Rui-De; Rotstein, Margaret A; Becnel, James J

    2007-11-01

    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.

  13. Can source reduction of mosquito larval habitat reduce malaria transmission in Tigray, Ethiopia?

    Science.gov (United States)

    Yohannes, Mekonnen; Haile, Mituku; Ghebreyesus, Tedros A; Witten, Karen H; Getachew, Asefaw; Byass, Peter; Lindsay, Steve W

    2005-12-01

    The development of irrigation schemes by dam construction has led to an increased risk of malaria in Tigray, Ethiopia. We carried out a pilot study near a microdam to assess whether environmental management could reduce malaria transmission by Anopheles arabiensis, the main vector in Ethiopia. The study took place in Deba village, close to a dam; Maisheru village, situated 3-4 km away from the dam, acted as a control. Baseline entomological and clinical data were collected in both villages during the first 12 months. Source reduction, involving filling, draining and shading of potential mosquito-breeding habitats was carried out by the community of Deba in the second year and routine surveillance continued in both villages during the second year. Anopheles arabiensis was highly anthropophilic (Human Blood Index=0.73), biting early in the night before people went to bed. The major breeding habitats associated with the dam were areas of seepage at the dam base (28%), leaking irrigation canals (16%), pools that formed along the bed of streams from the dam (13%), and man-made pools (12%). In the pre-intervention year, 5.9-7.2 times more adult vectors were found in the dam village compared with the control village. There was a 3.1% higher prevalence of an enlarged spleen in children under 10 years in the dam village than in the control village during the pre-intervention period, but no statistically significant difference was found in the incidence of falciparum malaria between the two villages during the same period. Source reduction was associated with a 49% (95% CI=46.6-50.0) relative reduction in An. arabiensis adults in the dam village compared with the pre-intervention period. There were very few cases of malaria during the intervention period in both villages making it impossible to judge whether malaria incidence had been reduced. These preliminary findings suggest that in areas of low intensity transmission community-led larval control may be a cheap and

  14. Carbon emission reductions by substitution of improved cookstoves and cattle mosquito nets in a forest-dependent community

    Directory of Open Access Journals (Sweden)

    Somanta Chan

    2015-07-01

    Substitution of conventional cookstoves with improved cookstoves and the use of mosquito nets instead of fuelwood burning could result in using less fuelwood for the same amount of energy needed and thereby result in reduction of carbon emissions and deforestation. To realize this substitution, approximately US$ 15–25 MgCO2−1 is needed depending on discount rates and amounts of emission reduction. Substitution of cookstoves will have direct impacts on the livelihoods of forest-dependent communities and on forest protection. Financial incentives under voluntary and mandatory schemes are needed to materialize this substitution.

  15. Reduction of malaria transmission by transgenic mosquitoes expressing an antisporozoite antibody in their salivary glands.

    Science.gov (United States)

    Sumitani, M; Kasashima, K; Yamamoto, D S; Yagi, K; Yuda, M; Matsuoka, H; Yoshida, S

    2013-02-01

    We have previously developed a robust salivary gland-specific expression system in transgenic Anopheles stephensi mosquitoes. To establish transgenic mosquito lines refractory to Plasmodium falciparum using this system, we generated a transgenic mosquito harbouring the gene encoding an anti-P. falciparum circumsporozoite protein (PfCSP) single-chain antibody (scFv) fused to DsRed in a secretory form (mDsRed-2A10 scFv). Fluorescence microscopy showed that the mDsRed-2A10 scFv was localized in the secretory cavities and ducts of the salivary glands in a secreted form. To evaluate P. falciparum transmission-blocking in a rodent malaria model, a transgenic Plasmodium berghei line expressing PfCSP in place of PbCSP (PfCSP/Pb) was constructed. The PfCSP/Pb parasites were able to bind to the mDsRed-2A10 scFv in the salivary glands of the transgenic mosquitoes. Importantly, the infectivity of the transgenic mosquitoes to mice was strongly impaired, indicating that the parasites had been inactivated. These results suggest that salivary gland-specific expression of antisporozoite molecules could be a promising strategy for blocking malaria transmission to humans. © 2012 Royal Entomological Society.

  16. Cost of Mating and Insemination Capacity of a Genetically Modified Mosquito Aedes aegypti OX513A Compared to Its Wild Type Counterpart

    Science.gov (United States)

    Bargielowski, Irka; Alphey, Luke; Koella, Jacob C.

    2011-01-01

    The idea of implementing genetics-based insect control strategies modelled on the traditional SIT is becoming increasingly popular. In this paper we compare a genetically modified line of Aedes aegypti carrying a tetracycline repressible, lethal positive feedback system (OX513A) with its wild type counterpart with respect to their insemination capacities and the cost of courtship and mating. Genetically modified males inseminated just over half as many females as the wild type males during their lifetime. Providing days of rest from mating had no significant effect on the total number of females inseminated by males of either line, but it did increase their longevity. Producing sperm had a low cost in terms of energy investment; the cost of transferring this sperm to a receptive female was much higher. Continued mating attempts with refractory females suggest that males could not identify refractory females before investing substantial energy in courtship. Although over a lifetime OX513A males inseminated fewer females, the number of females inseminated over the first three days, was similar between males of the two lines, suggesting that the identified cost of RIDL may have little impact on the outcome of SIT-based control programmes with frequent releases of the genetically modified males. PMID:22022518

  17. Laboratory and Field Evaluation of SS220 and Deet Against Mosquitoes in Queensland, Australia

    Science.gov (United States)

    2009-01-01

    methylpiperindinyl-3-cyclohexen-1-carboxamide] against mosquitoes in Queensland, Australia , were conducted. In the laboratory, both compounds provided...carboxa- mide], mosquito repellents, Culex annulirostris, Australia INTRODUCTION The use of personal protection measures, particularly the application...Queensland, Australia . MATERIALS AND METHODS Test mosquitoes Female mosquitoes used in the laboratory evaluation study were Ae. aegypti (Townsville

  18. Effects of inbreeding and genetic modification on Aedes aegypti larval competition and adult energy reserves

    Directory of Open Access Journals (Sweden)

    Kormaksson Matthias

    2010-10-01

    Full Text Available Abstract Background Genetic modification of mosquitoes offers a promising strategy for the prevention and control of mosquito-borne diseases. For such a strategy to be effective, it is critically important that engineered strains are competitive enough to serve their intended function in population replacement or reduction of wild mosquitoes in nature. Thus far, fitness evaluations of genetically modified strains have not addressed the effects of competition among the aquatic stages and its consequences for adult fitness. We therefore tested the competitive success of combinations of wild, inbred and transgenic (created in the inbred background immature stages of the dengue vector Aedes aegypti in the presence of optimal and sub-optimal larval diets. Results The wild strain of Ae. aegypti demonstrated greater performance (based on a composite index of survival, development rate and size than the inbred strain, which in turn demonstrated greater performance than the genetically modified strain. Moreover, increasing competition through lowering the amount of diet available per larva affected fitness disproportionately: transgenic larvae had a reduced index of performance (95-119% compared to inbred (50-88% and wild type larvae (38-54%. In terms of teneral energy reserves (glycogen, lipid and sugar, adult wild type mosquitoes had more reserves directly available for flight, dispersal and basic metabolic functions than transgenic and inbred mosquitoes. Conclusions Our study provides a detailed assessment of inter- and intra-strain competition across aquatic stages of wild type, inbred, and transgenic mosquitoes and the impact of these conditions on adult energy reserves. Although it is not clear what competitive level is adequate for success of transgenic strains in nature, strong gene drive mechanisms are likely to be necessary in order to overcome competitive disadvantages in the larval stage that carryover to affect adult fitness.

  19. Regulatory region of the vitellogenin receptor gene sufficient for high-level, germ line cell-specific ovarian expression in transgenic Aedes aegypti mosquitoes.

    Science.gov (United States)

    Cho, Kook-Ho; Cheon, Hyang-Mi; Kokoza, Vladimir; Raikhel, Alexander S

    2006-04-01

    Vitellogenin receptor (VgR) is responsible for the receptor-mediated endocytosis of vitellogenin (Vg) in the egg formation of an oviparous animal, including insects. Little is known about regulation of VgR gene expression. We analyzed the upstream region of the VgR gene from Aedes aegypti (AaVgR) to identify regulatory elements responsible for its expression in germ cell-specific ovarian expression. Experiments with genetic transformation using the transgene containing the 1.5-Kb upstream portion of the AaVgR gene fused with DsRed and the piggyBac vector showed that this regulatory region is sufficient for correct female and ovary-specific expression of the transgene. This 1.5-Kb upstream region contained binding sites for the ecdysone regulatory hierarchy early gene products E74 and BR-C, as well as transcription factors determining correct tissue- and stage-specific expression of GATA and HNF3/fkh. In situ hybridization demonstrated that in the ovaries of transgenic females DsRed mRNA was present in ovarian germ cells and nurse cells of mature ovarian follicles, together with VgR mRNA. In contrast, DsRed mRNA was absent in the oocyte that had a high level of endogenous VgR mRNA. Although the 1.5-Kb upstream region was sufficient to drive a high-level germ line cell-specific expression of the reporter, additional signals were required for translocation of exogenous mRNA from nurse cells into the oocyte.

  20. THAP and ATF-2 regulated sterol carrier protein-2 promoter activities in the larval midgut of the yellow fever mosquito, Aedes aegypti.

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    Rong Peng

    Full Text Available Expression of sterol carrier protein-2 (SCP-2 in Aedes aegypti shows a distinct temporal/spatial pattern throughout the life cycle. In order to identify the transcription factors responsible for the larval temporal/spatial regulation of AeSCP-2 transcription, AeSCP-2 promoter activities were studied in vivo via transient transfection of promoter/reporter gene assays. Regulatory sequences upstream -1.3 kb of the transcription start site of AeSCP-2 were found to be critical for the in vivo temporal/spatial promoter activity. Interestingly, the -1.6 kb promoter sequence efficiently drove the larval midgut-specific siRNA expression, indicating that the -1.6 kb upstream sequence is sufficient for temporal/spatial AeSCP-2 transcriptional activity. Four transcription factors were identified in the midgut nuclear extract from feeding larvae via labeled -1.6/-1.3 kb DNA probe pull-down and proteomic analysis. Co-transfection of the promoter/reporter gene with inducible siRNA expression of each transcription factor was performed to confirm the regulatory function of individual transcription factor on AeSCP-2 transcriptional activities in the larval midgut. The results indicate that two of the identified transcription factors, Thanatos-associated protein (THAP and activating transcription factor-2 (ATF-2, antagonistically control AeSCP-2 transcriptional activity in the midgut of feeding larvae via the regulatory sequences between -1.6 to -1.3 kb 5' upstream of the transcription start site. In vivo expression knockdown of THAP and ATF-2 resulted in significant changes in developmental progression, which may be partially due to their effects on AeSCP-2 expression.

  1. Expression of trypsin modulating oostatic factor (TMOF in an entomopathogenic fungus increases its virulence towards Anopheles gambiae and reduces fecundity in the target mosquito

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    Kamareddine Layla

    2013-01-01

    Full Text Available Abstract Background Adult and larval mosquitoes regulate food digestion in their gut with trypsin modulating oostatic factor (TMOF, a decapeptide hormone synthesized by the ovaries and the neuroendocrine system. TMOF is currently being developed as a mosquitocide, however, delivery of the peptide to the mosquito remains a significant challenge. Entomopathogenic fungi offer a means for targeting mosquitoes with TMOF. Findings The efficacy of wild type and transgenic Beauveria bassiana strains expressing Aedes aegypti TMOF (Bb-Aa1 were evaluated against larvae and sugar- and blood-fed adult Anopheles gambiae mosquitoes using insect bioassays. Bb-Aa1 displayed increased virulence against larvae, and sugar and blood fed adult A. gambiae when compared to the wild type parent strain. Median lethal dose (LD50 values decreased by ~20% for larvae, and ~40% for both sugar and blood-fed mosquitoes using Bb-Aa1 relative to the wild type parent. Median lethal time (LT50 values were lower for blood-fed compared to sugar-fed mosquitoes in infections with both wild type and Bb-Aa1. However, infection using Bb-Aa1 resulted in 15% to 25% reduction in LT50 values for sugar- and blood fed mosquitoes, and ~27% for larvae, respectively, relative to the wild type parent. In addition, infection with Bb-Aa1 resulted in a dramatic reduction in fecundity of the target mosquitoes. Conclusions B. bassiana expressing Ae. aegypti TMOF exhibited increased virulence against A. gambiae compared to the wild type strain. These data expand the range and utility of entomopathogenic fungi expressing mosquito-specific molecules to improve their biological control activities against mosquito vectors of disease.

  2. Cloning, characterization, and expression of microRNAs from the Asian malaria mosquito, Anopheles stephensi

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    Tu Zhijian

    2008-05-01

    Full Text Available Abstract Background microRNAs (miRNAs are non-coding RNAs that are now recognized as a major class of gene-regulating molecules widely distributed in metozoans and plants. miRNAs have been found to play important roles in apoptosis, cancer, development, differentiation, inflammation, longevity, and viral infection. There are a few reports describing miRNAs in the African malaria mosquito, Anopheles gambiae, on the basis of similarity to known miRNAs from other species. An. stephensi is the most important malaria vector in Asia and it is becoming a model Anopheline species for physiological and genetics studies. Results We report the cloning and characterization of 27 distinct miRNAs from 17-day old An. stephensi female mosquitoes. Seventeen of the 27 miRNAs matched previously predicted An. gambiae miRNAs, offering the first experimental verification of miRNAs from mosquito species. Ten of the 27 are miRNAs previously unknown to mosquitoes, four of which did not match any known miRNAs in any organism. Twenty-five of the 27 Anopheles miRNAs had conserved sequences in the genome of a divergent relative, the yellow fever mosquito Aedes aegypti. Two clusters of miRNAs were found within introns of orthologous genes in An. gambiae, Ae. aegypti, and Drosophila melanogaster. Mature miRNAs were detected in An. stephensi for all of the nine selected miRNAs, including the four novel miRNAs (miR-x1- miR-x4, either by northern blot or by Ribonuclease Protection Assay. Expression profile analysis of eight of these miRNAs revealed distinct expression patterns from early embryo to adult stages in An. stephensi. In both An. stephensi and Ae. aegypti, the expression of miR-x2 was restricted to adult females and predominantly in the ovaries. A significant reduction of miR-x2 level was observed 72 hrs after a blood meal. Thus miR-x2 is likely involved in female reproduction and its function may be conserved among divergent mosquitoes. A mosquito homolog of miR-14, a

  3. Burchellin: study of bioactivity against Aedes aegypti.

    Science.gov (United States)

    Narciso, Juliana Oliveira Abreu; Soares, Renata Oliveira de Araújo; Reis dos Santos Mallet, Jacenir; Guimarães, Anthony Érico; de Oliveira Chaves, Maria Célia; Barbosa-Filho, José Maria; Maleck, Marise

    2014-04-08

    The dengue mosquito Aedes aegypti Linnaeus, 1762 is a widespread insect pest of serious medical importance. Since no effective vaccine is available for treating dengue, the eradication or control of the main mosquito vector is regarded as essential. Since conventional insecticides have limited success, plants may be an alternative source of larvicidal agents, since they contain a rich source of bioactive chemicals. The aim of this study was to evaluate the larvicidal activity of the neolignan burchellin isolated from Ocotea cymbarum (Lauraceae), a plant from the Amazon region, against third instar larvae of A. aegypti. Burchellin obtained from O. cymbarum was analyzed. The inhibitory activity against A. aegypti eggs and larvae and histological changes in the digestive system of treated L3 larvae were evaluated. In addition, nitric oxide synthase activity and nitric oxide levels were determined, and cytotoxicity bioassays performed. The data showed that burchellin interfered with the development cycle of the mosquito, where its strongest toxic effect was 100% mortality in larvae (L3) at concentrations ≥ 30 ppm. This compound did not show target cell toxicity in peritoneal macrophages from BALB/c mice, and proved to have molecular stability when dissolved in water. The L3 and L4 larvae treated with the compound showed cellular destruction and disorganization, cell spacing, and vacuolization of epithelial cells in small regions of the midgut. The neolignan burchellin proved to be a strong candidate for a natural, safe and stable phytolarvicidal to be used in population control of A. aegypti.

  4. Monitoramento do mosquito Aedes aegypti (Linnaeus, 1762 (Diptera: Culicidae, por meio de ovitrampas no Campus da Universidade Federal de Mato Grosso, Cuiabá, Estado de Mato Grosso Monitoring of Aedes aegypti mosquitoes (Linnaeus, 1762 (Diptera: Culicidae by means of ovitraps at the Universidade Federal de Mato Grosso Campus, Cuiabá, State of Mato Grosso

    Directory of Open Access Journals (Sweden)

    Rosina Djunko Miyazaki

    2009-08-01

    Full Text Available A dengue é uma das mais importantes arboviroses que atinge o homem e constitui um sério problema de saúde nas áreas tropicais, cujas condições climáticas são favoráveis à ocorrência de focos de Aedes aegypti. Armadilhas de oviposição acrescidas de infusão de feno foram instaladas em 19 pontos no Campus da Universidade Federal de Mato Grosso com o objetivo de verificar mensalmente o nível de infestação do vetor da dengue e a influência dos fatores abióticos. Os resultados obtidos foram comparados com dados abióticos de temperatura e umidade relativa do ar, e de precipitação pluviométrica, mensais e dos dias que as armadilhas permaneceram no campo. A chuva é o único fator abiótico que apresenta influência no nível de infestação dos vetores da dengue no local. Existem diferenças significativas entre as quantidades de ovos de Aedes aegypti encontrados em diferentes locais de coleta na mesma área de estudo. O número de ovos encontrados em cada ponto ao longo do ano não obedece a um padrão de distribuição único.TDengue is one of the most important arboviruses affecting man and is a serious health problem in tropical areas where climatic conditions are favorable for occurrences of foci of Aedes aegypti. Oviposition traps with added hay infusion were installed at 19 points on the campus of the Federal University of Mato Grosso with the objective of investigating the monthly levels of infestation with the dengue vector and the influence of abiotic factors. The results obtained were compared with the following monthly abiotic data: temperature, relative air humidity and precipitation; and with the number of days for which the traps remained in the field. Rain was the only abiotic factor that influenced the level of infestation of the dengue vector at this location. There were significant differences between the quantities of Aedes aegypti eggs found at different sites within the same study area. The numbers of eggs

  5. Evaluation of Six Mosquito Traps for Collection of Aedes albopictus and Associated Mosquito Species in a Suburban Setting in North Central Florida

    Science.gov (United States)

    2009-03-01

    aegypti and Ae. albopictus are the most important yellow fever and dengue virus vectors in most of the world. Although Ae. aegypti prefer- entially...EVALUATION OF SIX MOSQUITO TRAPS FOR COLLECTION OF AEDES ALBOPICTUS AND ASSOCIATED MOSQUITO SPECIES IN A SUBURBAN SETTING IN NORTH CENTRAL FLORIDA1 D...F. HOEL,1 D. L. KLINE2 AND S. A. ALLAN2 ABSTRACT. We compared 6 adult mosquito traps for effectiveness in collecting Aedes albopictus from suburban

  6. PENGARUH EKSTRAK BATANG BROTOWALI (Tinospora crispa) TERHADAP KEMATIAN LARVA NYAMUK Aedes aegypti

    OpenAIRE

    Agustiani Dumeva; Syarifah Syarifah; Syahidah Fitriah

    2016-01-01

    Aedes aegypti mosquito, which acts as a vector in the spread of dengue disease. One of the effort to reduce the spread of dengue disease is using larvicides. Brotowali thought to have an effect as larvicides against Aedes aegypti larvae because they have the alkaloid compounds and tinokrisposid that can cause death in larvae. This study aims to determine the effect extract brotowali (Tinospora crispa) against Aedes aegypti larvae of death so as to provide information to the public...

  7. Mosquito Control

    Science.gov (United States)

    ... Protection Agency Search Search Contact Us Share Mosquito Control About Mosquitoes General Information Life Cycle Information from ... Repellent that is Right for You DEET Mosquito Control Methods Success in mosquito control: an integrated approach ...

  8. History of domestication and spread of Aedes aegypti - A Review

    Directory of Open Access Journals (Sweden)

    Jeffrey R Powell

    2013-01-01

    Full Text Available The adaptation of insect vectors of human diseases to breed in human habitats (domestication is one of the most important phenomena in medical entomology. Considerable data are available on the vector mosquito Aedes aegypti in this regard and here we integrate the available information including genetics, behaviour, morphology, ecology and biogeography of the mosquito, with human history. We emphasise the tremendous amount of variation possessed by Ae. aegypti for virtually all traits considered. Typological thinking needs to be abandoned to reach a realistic and comprehensive understanding of this important vector of yellow fever, dengue and Chikungunya.

  9. [Aedes aegypti control strategies: a review].

    Science.gov (United States)

    Zara, Ana Laura de Sene Amâncio; Santos, Sandra Maria Dos; Fernandes-Oliveira, Ellen Synthia; Carvalho, Roberta Gomes; Coelho, Giovanini Evelim

    2016-01-01

    to describe the main strategies to control Aedes aegypti, with emphasis on promising technological innovations for use in Brazil. this study is a non-systematic review of the literature. several technologies have been developed as alternatives in the control of Ae. aegypti, using different mechanisms of action, such as selective monitoring of the infestation, social interventions, dispersing insecticides, new biological control agents and molecular techniques for population control of mosquitoes, also considering the combination between them. Evolving technologies require evaluation of the effectiveness, feasibility and costs of implementation strategies as complementary to the actions already recommended by the National Program for Dengue Control. the integration of different compatible and effective vector control strategies, considering the available technologies and regional characteristics, appears to be a viable method to try to reduce the infestation of mosquitoes and the incidence of arbovirus transmitted by them.

  10. Dengue virus transovarial transmission by Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Monica Dwi Hartanti

    2010-08-01

    Full Text Available Dengue is a disease that is caused by dengue virus and transmitted to humans through the bite of infected Aedes mosquitoes, especially Aedes aegypti. The disease is hyper-endemic in Southeast Asia, where a more severe form, dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS, is a major public health concern. The purpose of the present study was to find evidence of dengue virus transovarial transmision in local vectors in Jakarta. Fifteen Aedes larvae were collected in 2009 from two areas in Tebet subdistrict in South Jakarta, namely one area with the highest and one with the lowest DHF prevalence. All mosquitoes were reared inside two cages in the laboratory, eight mosquitoes in one cage and seven mosquitoes in another cage and given only sucrose solution as their food. The results showed that 20% of the mosquitoes were positive for dengue virus. Dengue virus detection with an immunohistochemical method demonstrated the occurrence of transovarial transmission in local DHF vectors in Tebet subdistrict. Transovarial dengue infection in Ae.aegypti larvae appeared to maintain or enhance epidemics. Further research is needed to investigate the relation of dengue virus transovarial transmission with DHF endemicity in Jakarta.

  11. PENGARUH KONSENTRASI AIR REBUSAN DAUN SIRSAK (Annona muricata Linn TERHADAP PERTUMBUHAN LARVA NYAMUK Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Diah Ariana

    2016-02-01

    Abstract Leaves of the soursop (Annona muricata Linn Indonesia is known as a medicinal plant that can treat a variety of diseases other than as a cure soursop leaves is also an insecticide-producing plants are bioactive compounds known as acetogenin which are bioactive compounds in high concentrations can be toxic to insects, thus may cause the insects will not eat. At low concentrations of toxic by oral administration stomach and can cause death. Soursop leaves are pesticides from natural elements that can be decided by the Aedes aegypti mosquito generation above background can be taken formulation of the problem Is there any effect of the concentration of soursop leaves boiled water (Annona muricata Linn on the growth of mosquito larvae of Aedes aegypti? This study aimed to determine the effect of water concentration on the growth of soursop leaf decoction Aedes aegypti mosquito larvae.The design of this study used an experimental design with laboratory testing, soursop leaf decoction obtained by weigh 100 g and dissolved in 100 ml of distilled water generated lau soursop leaves boiled water. The inhibition assay performed on boiled water boiling water concentration 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% and visits by the number of larvae of Aedes aegypti mosquitoes that die in 24 hours after treatment. Statistical analysis using Annova test with significance level 0.05 for determining the presence or absence of the influence of water concentration on the growth of soursop leaf decoction mosquito Aedes aegypti and subsequent Tukey HSD test was done to see the differences in each concentration. The results showed concentrations of 10% to 100% can inhibit the growth of mosquito larvae of Aedes aegypti, so it can be concluded that the soursop leaves can inhibit the growth of mosquito larvae of Aedes aegypti and efficient soursop leaves is used for patients with antibacterial, antifungal, anticonvulsant, and anti-inflammatory. Keyword :  larvae of Aedes

  12. Insecticide susceptibility status of human biting mosquitoes in ...

    African Journals Online (AJOL)

    This situation presents a challenge to chemicals that are currently used to control mosquitoes in sub-Saharan African. Furthermore, there is limited ... Results: Mosquito species tested were Anopheles gambiae s.l., An. funestus, Aedes aegypti, and Culex quinquefasciatus species. Real-time PCR have showed that the main ...

  13. Intraspecific Competition and Population Dynamics of Aedes aegypti

    Science.gov (United States)

    Paixão, C. A.; Charret, I. C.; Lima, R. R.

    2012-04-01

    We report computational simulations for the evolution of the population of the dengue vector, Aedes aegypti mosquitoes. The results suggest that controlling the mosquito population, on the basis of intraspecific competition at the larval stage, can be an efficient mechanism for controlling the spread of the epidemic. The results also show the presence of a kind of genetic evolution in vector population, which results mainly in increasing the average lifespan of individuals in adulthood.

  14. Aedes aegypti survival in the presence of Toxorhynchites violaceus (Diptera: Culicidae fourth instar larvae

    Directory of Open Access Journals (Sweden)

    Daniel S Albeny

    2011-08-01

    Full Text Available The mosquito Aedes aegypti (Linnaeus, 1762 is the main vector of dengue and yellow fever viruses. Different methods have been used to control A. aegypti, including chemical and biological tools. However, chemical control can lead to a subsequent increase in the mosquitoes' insecticide resistance, and biological control represents an important method as an alternative to insecticide usage. Larvae from the Toxorhynchites genus (Diptera: Culicidae are predators of other mosquitoes and represent a potential natural biocontrol agent of A. aegypti larvae. In the present work, A. aegypti larval survival was studied in the presence of the neotropical Toxorhynchites violaceus (Wiedemann, 1821 fourth instar larvae. Toxorhynchites violaceus consumption of A. aegypti increased during the 192 hours of the experiment and was more marked in the intervals between 96 and 120 hours and between 168 and 192 hours, when the A. aegypti survival reached 0%. During the fourth instar, T. violaceus increased its predation on A. aegypti larvae, possibly in order to increase its nutrient storage prior to pupation. Otherwise, low prey consumption can lead to a nutritional deficit for the larvae, delaying the adult's sexual development and reducing its egg production. Here we show that A. aegypti survival can be reduced by the T. violaceus fourth larvae predation under laboratory conditions

  15. Expression Profiles and RNAi Silencing of Inhibitor of Apoptosis Transcripts in Aedes, Anopheles, and Culex Mosquitoes (Diptera: Culicidae).

    Science.gov (United States)

    Puglise, Jason M; Estep, Alden S; Becnel, James J

    2016-03-01

    Effective mosquito control is vital to curtail the devastating health effects of many vectored diseases. RNA interference (RNAi)-mediated control of mosquitoes is an attractive alternative to conventional chemical pesticides. Previous studies have suggested that transcripts for inhibitors of apoptosis (IAPs) may be good RNAi targets. To revisit and extend previous reports, we examined the expression of Aedes aegypti (L.) IAPs (AaeIAPs) 1, 2, 5, 6, 9, and a viral IAP-associated factor (vIAF) as well as Anopheles quadrimaculatus Say and Culex quinquefasciatus Say IAP1 homologs (AquIAP1 and CquIAP1) in adult females. Expression profiles of IAPs suggested that some older female mosquitoes had significantly higher IAP mRNA levels when compared to the youngest ones. Minor differences in expression of AaeIAPs were observed in mosquitoes that imbibed a bloodmeal, but the majority of the time points (up to 48 h) were not significantly different. Although in vitro experiments with the Ae. aegypti Aag-2 cell line demonstrated that the various AaeIAPs could be effectively knocked down within one day after dsRNA treatment, only Aag-2 cells treated with dsIAP1 displayed apoptotic morphology. Gene silencing and mortality were also evaluated after topical application and microinjection of the same dsRNAs into female Ae. aegypti. In contrast to previous reports, topical administration of dsRNA against AaeIAP1 did not yield a significant reduction in gene expression or increased mortality. Knockdown of IAP1 and other IAPs by microinjection did not result in significant mortality. In toto, our findings suggest that IAPs may not be suitable RNAi targets for controlling adult mosquito populations.

  16. Suppression of Brugia malayi (sub-periodic larval development in Aedes aegypti (Liverpool strain fed on blood of animals immunized with microfilariae

    Directory of Open Access Journals (Sweden)

    K Athisaya Mary

    2005-07-01

    Full Text Available Preliminary studies were carried out to investigate the role of filarial specific antibodies, raised in an animal model against the filarial parasite, Brugia malayi (sub-periodic, in blocking their early development in an experimental mosquito host, Aedes aegypti (Liverpool strain. In order to generate filarial specific antibodies, Mongolian gerbils, Meriones unguiculatus, were immunized either with live microfilariae (mf of B. malayi or their homogenate. Mf were harvested from the peritoneal cavity of Mongolian gerbils with patent infection of B. malayi and fed to A. aegypti along with the blood from immunized animals. Development of the parasite in infected mosquitoes was monitored until they reached infective stage larvae (L3. Fewer number of parasites developed to first stage (L1 and subsequently to L2 and L3 in mosquitoes fed with blood of immunized animals, when compared to those fed with blood of control animals. The results thus indicated that filarial parasite specific antibodies present in the blood of the immunized animals resulted in the reduction of number of larvae of B. malayi developing in the mosquito host.

  17. First Report of Aedes aegypti Transmission of Chikungunya Virus in the Americas

    Science.gov (United States)

    Díaz-González, Esteban E.; Kautz, Tiffany F.; Dorantes-Delgado, Alicia; Malo-García, Iliana R.; Laguna-Aguilar, Maricela; Langsjoen, Rose M.; Chen, Rubing; Auguste, Dawn I.; Sánchez-Casas, Rosa M.; Danis-Lozano, Rogelio; Weaver, Scott C.; Fernández-Salas, Ildefonso

    2015-01-01

    During a chikungunya fever outbreak in late 2014 in Chiapas, Mexico, entomovirological surveillance was performed to incriminate the vector(s). In neighborhoods, 75 households with suspected cases were sampled for mosquitoes, of which 80% (60) harbored Aedes aegypti and 2.7% (2) Aedes albopictus. A total of 1,170 Ae. aegypti and three Ae. albopictus was collected and 81 pools were generated. Although none of the Ae. albopictus pools were chikungunya virus (CHIKV)–positive, 18 Ae. aegypti pools (22.8%) contained CHIKV, yielding an infection rate of 32.3/1,000 mosquitoes. A lack of herd immunity in conjunction with high mosquito populations, poor vector control services in this region, and targeted collections in locations of human cases may explain the high infection rate in this vector. Consistent with predictions from experimental studies, Ae. aegypti appears to be the principal vector of CHIKV in southern Mexico, while the role of Ae. albopictus remains unknown. PMID:26416113

  18. Oviposition-stimulant and ovicidal activities of Moringa oleifera lectin on Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Nataly Diniz de Lima Santos

    Full Text Available Natural insecticides against the vector mosquito Aedes aegypti have been the object of research due to their high level of eco-safety. The water-soluble Moringa oleifera lectin (WSMoL is a larvicidal agent against A. aegypti. This work reports the effects of WSMoL on oviposition and egg hatching of A. aegypti.WSMoL crude preparations (seed extract and 0-60 protein fraction, at 0.1 mg/mL protein concentration, did not affect oviposition, while A. aegypti gravid females laid their eggs preferentially (73% in vessels containing isolated WSMoL (0.1 mg/mL, compared with vessels containing only distilled water (control. Volatile compounds were not detected in WSMoL preparation. The hatchability of fresh eggs deposited in the solutions in the oviposition assay was evaluated. The numbers of hatched larvae in seed extract, 0-60 protein fraction and WSMoL were 45 ± 8.7 %, 20 ± 11 % and 55 ± 7.5 %, respectively, significantly (p<0.05 lower than in controls containing only distilled water (75-95%. Embryos were visualized inside fresh control eggs, but not within eggs that were laid and maintained in WSMoL solution. Ovicidal activity was also assessed using stored A. aegypti eggs. The protein concentrations able to reduce the hatching rate by 50% (EC50 were 0.32, 0.16 and 0.1 mg/mL for seed extract, 0-60 protein fraction and WSMoL, respectively. The absence of hatching of stored eggs treated with WSMoL at 0.3 mg/mL (EC99 after transfer to medium without lectin indicates that embryos within the eggs were killed by WSMoL. The reduction in hatching rate of A. aegypti was not linked to decrease in bacteria population.WSMoL acted both as a chemical stimulant cue for ovipositing females and ovicidal agent at a given concentration. The oviposition-stimulant and ovicidal activities, combined with the previously reported larvicidal activity, make WSMoL a very interesting candidate in integrated A. aegypti control.

  19. Seasonal Genetic Changes of Aedes aegypti (Diptera: Culicidae) Populations in Selected Sites of Cebu City, Philippines.

    Science.gov (United States)

    Sayson, S L; Gloria-Soria, A; Powell, J R; Edillo, F E

    2015-07-01

    Aedes aegypti (L.) is the primary vector of dengue virus in the Philippines, where dengue is endemic. We examined the genetic changes of Ae. aegypti collected from three selected sites in Cebu city, Philippines, during the relatively wet (2011-2012) and dry seasons (2012 and 2013). A total of 493 Ae. aegypti adults, reared in the laboratory from field-collected larvae, were analyzed using 11 microsatellite loci. Seasonal variation was observed in allele frequencies and allelic richness. Average genetic differentiation (DEST=0.018; FST=0.029) in both dry seasons was higher, due to reduced Ne, than in the wet season (DEST=0.006; FST=0.009). Thus, average gene flow was higher in the wet season than in the dry seasons. However, the overall FST estimate (0.02) inclusive of the two seasons showed little genetic differentiation as supported by Bayesian clustering analysis. Results suggest that during the dry season the intense selection that causes a dramatic reduction of population size favors heterozygotes, leading to small pockets of mosquitoes (refuges) that exhibit random genetic differentiation. During the wet season, the genetic composition of the population is reconstituted by the expansion of the refuges that survived the preceding dry season. Source reduction of mosquitoes during the nonepidemic dry season is thus recommended to prevent dengue re-emergence in the subsequent wet season. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Mosquito repellency of the seeds of celery (Apium graveolens L.).

    Science.gov (United States)

    Tuetun, B; Choochote, W; Rattanachanpichai, E; Chaithong, U; Jitpakdi, A; Tippawangkosol, P; Riyong, D; Pitasawat, B

    2004-06-01

    When the mosquito repellencies of four fractions of Apium graveolens seeds (one hexane, two dichloromethane and one methanolic) were investigated in the laboratory, all four were found to offer human volunteers some protection against female, adult Aedes aegypti. The hexane fraction, however, was found to exhibit the highest repellency in the laboratory, with median effective doses (ED50) and ED95 of 0.41 and 2.93 mg/cm2 skin, respectively. Only this fraction, which was also found to provide protection against mosquito bites for 3.5 h when applied, in the laboratory, at a concentration of 250 mg/ml, was then investigated for its repellency in the field and its stability. In storage, it was found to retain its repellency for at least 2 months, although significant reductions in its repellency were observed (in terms of shortened complete-protection times) after 3 months, whatever the temperature of storage (-20 degrees C, 4 degrees C, or room temperature). When applied to the skin of volunteers under field conditions, the hexane fraction showed strong repellent activity against a wide range of mosquito species belonging to various genera (Ae. gardnerii, Ae. lineatopennis, Armigeres subalbatus, Culex tritaeniorhynchus, Cx. vishnui group, Cx. quinquefasciatus and Mansonia uniformis). It appeared not to cause dermal irritation or any other adverse effect, either during 6 months of use or in the following 3 months of follow-up. Mosquito repellents based on extracts of Ap. graveolens seeds could be developed commercially, as an effective personal-protection measure against mosquito bites and the diseases caused by mosquito-borne pathogens.

  1. Developmental neurogenetics of sexual dimorphism in Aedes aegypti.

    Science.gov (United States)

    Duman-Scheel, Molly; Syed, Zainulabeuddin

    Sexual dimorphism, a poorly understood but crucial aspect of vector mosquito biology, encompasses sex-specific physical, physiological, and behavioral traits related to mosquito reproduction. The study of mosquito sexual dimorphism has largely focused on analysis of the differences between adult female and male mosquitoes, particularly with respect to sex-specific behaviors related to disease transmission. However, sexually dimorphic behaviors are the products of differential gene expression that initiates during development and therefore must also be studied during development. Recent technical advancements are facilitating functional genetic studies in the dengue vector Aedes aegypti, an emerging model for mosquito development. These methodologies, many of which could be extended to other non-model insect species, are facilitating analysis of the development of sexual dimorphism in neural tissues, particularly the olfactory system. These studies are providing insight into the neurodevelopmental genetic basis for sexual dimorphism in vector mosquitoes.

  2. Circadian clock of Aedes aegypti: effects of blood-feeding, insemination and RNA interference

    Science.gov (United States)

    Gentile, Carla; Rivas, Gustavo Bueno da S; Lima, José BP; Bruno, Rafaela Vieira; Peixoto, Alexandre Afranio

    2013-01-01

    Mosquitoes are the culprits of some of the most important vector borne diseases. A species’ potential as a vector is directly dependent on their pattern of behaviour, which is known to change according to the female’s physiological status such as whether the female is virgin/mated and unfed/blood-fed. However, the molecular mechanism triggered by and/or responsible for such modulations in behaviour is poorly understood. Clock genes are known to be responsible for the control of circadian behaviour in several species. Here we investigate the impact mating and blood-feeding have upon the expression of these genes in the mosquito Aedes aegypti . We show that blood intake, but not insemination, is responsible for the down-regulation of clock genes. Using RNA interference, we observe a slight reduction in the evening activity peak in the fourth day after dstim injection. These data suggest that, as in Drosophila , clock gene expression, circadian behaviour and environmental light regimens are interconnected in Ae. aegypti . PMID:24473806

  3. Effects of Zika Virus Strain and Aedes Mosquito Species on Vector Competence

    Science.gov (United States)

    Bialosuknia, Sean M.; Zink, Steven D.; Brecher, Matthew; Ehrbar, Dylan J.; Morrissette, Madeline N.; Kramer, Laura D.

    2017-01-01

    In the Western Hemisphere, Zika virus is thought to be transmitted primarily by Aedes aegypti mosquitoes. To determine the extent to which Ae. albopictus mosquitoes from the United States are capable of transmitting Zika virus and the influence of virus dose, virus strain, and mosquito species on vector competence, we evaluated multiple doses of representative Zika virus strains in Ae. aegypti and Ae. albopictus mosquitoes. Virus preparation (fresh vs. frozen) significantly affected virus infectivity in mosquitoes. We calculated 50% infectious doses to be 6.1–7.5 log10 PFU/mL; minimum infective dose was 4.2 log10 PFU/mL. Ae. albopictus mosquitoes were more susceptible to infection than Ae. aegypti mosquitoes, but transmission efficiency was higher for Ae. aegypti mosquitoes, indicating a transmission barrier in Ae. albopictus mosquitoes. Results suggest that, although Zika virus transmission is relatively inefficient overall and dependent on virus strain and mosquito species, Ae. albopictus mosquitoes could become major vectors in the Americas. PMID:28430564

  4. Neuropeptidomics of the Mosquito Aedes Aegypti

    Science.gov (United States)

    2010-01-01

    Characterization of crustacean cardioactive peptide as a novel insect midgut factor: Isolation, localization, and stimulation of alpha - amylase activity and gut...XP_311578 Protein hormones (>3000 Da) Bursicon- alpha subunit gb|AAGE02007773.1| ND CG13419 AY735443 gb|AAGE02011233.1| Bursicon-beta subunit gb|AAGE02026399.1...hormone 5 gb|AAGE02010971.1| gb|XM_001652153.1| Glycoprotein hormone alpha 2 (GPA2) gb|AAGE02002350.1| gb|BN001241.1| AAX38184.1 XP_317164

  5. PEMANFAATAN RADIOISOTOP 32P UNTUK PENANDAAN (LABELLED COMPOUND PADA NYAMUK Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Akhid Darwin

    2012-07-01

    Full Text Available An Ae. aegypti mosquitoes labelling with Radioisotop 32P was performed at various dose application. The research conducted by Insitute of Vector and Reservoir Control Research and Development, Salatiga in collaboration with The National of Atomic Agency that aimed to know the effective dose and radioactivity disposal of the Radioisotop 32 P. The research used several doses: 0,3 µCi (micro currie; 0,5 µCi; and 0,7 µCi of each 25 gr larvaefood for 50 larvae with dry and wet radiation then observed the effect of radiation against larvae stadium and mosquitoes. The result shows that at 0,5 pCi isotop 32P dose application, Ae. aegypti mosquitoe can survive with 333,3 cps (currie per second residual radioactivity and detected in 75 cm distance. The Radioisotop 32P can be used as Ae. aegypti mosquitoes labelling/marking.

  6. Biting Deterrence and Insecticidal Activity of Hydrazide-Hydrazones and Their Corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles Against Aedes aegypti

    Science.gov (United States)

    2012-09-11

    larvicidal; Aedes aegypti 1 INTRODUCTION Mosquito-borne diseases are major health problems worldwide. The yellow fever mosquito, Aedes aegypti L., can be...bisacylhydrazine9 showed sig- nificant insecticidal activity against Aedes albopictus , Drosophila melanogaster, Aedes aegypti and Chironomus tentans. Boger et... Aedes albopictus . Bioorg Med Chem Lett 21:794–797 (2011). 9 Dhadialla TS, Le D, Palli SR, Raikheld A and Carlson GR, A photoaffinity, non-steroidal

  7. Aktivitas Beberapa Atraktan Pada Perangkap Telur Berperekat Terhadap Aedes aegypti

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    Milana Salim

    2017-02-01

    Full Text Available AbstractControl of Aedes aegypti mosquito as dengue haemorrhagic fever/DHF vector can be conducted using the ovitrap modified into a sticky ovitrap. The addition of attractant substances to the ovitrap can attract more mosquitoes comes to the trap, and prevent mosquitoes laying eggs in other places. The aim of this research was to compare hay infusion water and larva rearing water as attractant which combined with sugar-apple (Annona squamosa seed extract by counting the mosquitoes and eggs trapped. This research used six types medium: hay infusion water, larva rearing water, hay infusion water + sugar-apple seed extract, larva rearing water + sugar-apple seed extract, aquadest + sugar-apple seed extract, and aquadest only as a control. Sample used were 25 gravid female of Ae. aegypti mosquitoes with five replications. Mosquitoes and eggs which trapped were counted. This research showed that the number of mosquito trapped and eggs hatched more found in sticky ovitrap with hay infusion water. Statistic analyzed by ANOVA showed that there is no significant difference towards number off mosquito trapped in sticky ovitrap (p>0,05 whereas the medium material has significant difference towards number off egg hatched than others (p<0,05.Keywords: Sticky ovitrap, attractant, Aedes aegypti AbstrakPengendalian nyamuk Aedes aegypti sebagai vektor demam berdarah dengue/DBD dapat dilakukan menggunakan ovitrap yang dimodifikasi dengan perekat menjadi sticky ovitrap. Penambahan atraktan pada ovitrap dapat menarik lebih banyak nyamuk datang ke perangkap yang dipasang dan mencegah nyamuk bertelur di tempat lain. Tujuan penelitian ini adalah untuk mengetahui aktivitas atraktan air rendaman jerami dan air bekas kolonisasi yang dikombinasikan dengan ekstrak biji srikaya pada sticky ovitrap terhadap jumlah nyamuk dan telur yang ditemukan. Enam jenis media uji digunakan dalam penelitian ini yaitu air rendaman jerami, air bekas kolonisasi nyamuk, air rendaman jerami

  8. Mosquitoes, models, and dengue.

    Science.gov (United States)

    Lifson, A R

    1996-05-04

    In the last 10 years dengue has spread markedly through Latin America and the Caribbean (Dominican Republic, Jamaica, Barbados, Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Ecuador, Colombia, Venezuela, and Brazil). The mosquito Aedes aegypti has taken advantage of increased urbanization and crowding to transmit the dengue virus. The mosquito infests tires, cans, and water jars near dwellings. The female mosquito practices multiple, interrupted feeding. Thus, mosquito infesting and feeding practices facilitate dengue transmission in crowded conditions. Factors contributing to the spread of dengue include numbers of infected and susceptible human hosts, strain of dengue virus, size of mosquito population, feeding habits, time from infection to ability to transmit virus for both vector and host, likelihood of virus transmission from human to mosquito to human, and temperature (which affects vector distribution, size, feeding habits, and extrinsic incubation period). Public health models may use simulation models to help them plan or evaluate the potential impact of different intervention strategies and/or of environmental changes (e.g., global warming). Other factors contributing to the dengue epidemic are international travel, urbanization, population growth, crowding, poverty, a weakened public health infrastructure, and limited support for sustained disease control programs. Molecular epidemiology by nucleic acid sequence analysis is another sophisticated technique used to study infectious diseases. It showed that dengue type 3 isolated from Panama and Nicaragua in 1994 was identical to that responsible for the major dengue hemorrhagic fever epidemics in Sri Lanka and India in the 1980s. Public health officials must remember three priorities relevant to dengue and other emerging infections: the need to strengthen surveillance efforts, dedicated and sustained involvement in prevention and control needs at the local level, and a strong

  9. Targeted genome editing in Aedes aegypti using TALENs.

    Science.gov (United States)

    Aryan, Azadeh; Myles, Kevin M; Adelman, Zach N

    2014-08-15

    The Culicine mosquito, Aedes aegypti, is both a major vector of arthropod-borne viruses (arboviruses) and a genetic model organism for arbovirus transmission. TALE nucleases (TALENs), a group of artificial enzymes capable of generating site-specific DNA lesions, consist of a non-specific FokI endonuclease cleavage domain fused to an engineered DNA binding domain specific to a target site. While TALENs have become an important tool for targeted gene disruption in a variety of organisms, application to the mosquito genome is a new approach. We recently described the use of TALENs to perform heritable genetic disruptions in A. aegypti. Here, we provide detailed methods that will allow other research laboratories to capitalize on the potential of this technology for understanding mosquito gene function. We describe target site selection, transient embryo-based assays to rapidly assess TALEN activity, embryonic microinjection and downstream screening steps to identify target site mutations. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Identification of germline transcriptional regulatory elements in Aedes aegypti

    Science.gov (United States)

    Akbari, Omar S.; Papathanos, Philippos A.; Sandler, Jeremy E.; Kennedy, Katie; Hay, Bruce A.

    2014-02-01

    The mosquito Aedes aegypti is the principal vector for the yellow fever and dengue viruses, and is also responsible for recent outbreaks of the alphavirus chikungunya. Vector control strategies utilizing engineered gene drive systems are being developed as a means of replacing wild, pathogen transmitting mosquitoes with individuals refractory to disease transmission, or bringing about population suppression. Several of these systems, including Medea, UDMEL, and site-specific nucleases, which can be used to drive genes into populations or bring about population suppression, utilize transcriptional regulatory elements that drive germline-specific expression. Here we report the identification of multiple regulatory elements able to drive gene expression specifically in the female germline, or in the male and female germline, in the mosquito Aedes aegypti. These elements can also be used as tools with which to probe the roles of specific genes in germline function and in the early embryo, through overexpression or RNA interference.

  11. Recomendaciones para la vigilancia de Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Roberto Barrera

    2016-09-01

    Full Text Available La enfermedades causadas por arbovirus transmitidos por Aedes aegypti, como el dengue, el chikungunya y el zika, continúan aumentando en incidencia anual y expansión geográfica. Una limitación clave para el control de A. aegypti ha sido la ausencia de herramientas eficaces para vigilar su población y poder determinar las medidas de control que realmente funcionan. La vigilancia de A. aegypti se ha basado principalmente en la obtención de los índices aédicos, los cuales guardan poca relación con el número de hembras del mosquito, que son las responsables de la transmisión de los virus. El reciente desarrollo de técnicas de muestreo de adultos de este vector promete facilitar las labores de vigilancia y control. En esta revisión se presentan las diversas técnicas de vigilancia del mosquito, así como una discusión sobre su utilidad, con recomendaciones para lograr una vigilancia entomológica más efectiva.

  12. The impact of transgenic mosquitoes on dengue virulence to humans and mosquitoes.

    Science.gov (United States)

    Medlock, Jan; Luz, Paula M; Struchiner, Claudio J; Galvani, Alison P

    2009-10-01

    Dengue is a major public health concern in the tropics and subtropics. Innovative transgenic strategies to render Aedes aegypti mosquitoes, the primary vector of dengue, incompetent for dengue transmission are under development. We modeled the evolutionary impact of different transgenic mosquito strategies on dengue-induced mortality, that is, dengue virulence, to both humans and mosquitoes. This model incorporates various evolutionary trade-offs in dengue virus epidemiological traits, for example, a trade-off between dengue transmission rate and its virulence to humans. Our results indicate that strategies that block transmission or reduce mosquito biting impose selection on dengue virulence in humans. This selection can be for either higher or lower virulence, depending on the interaction between the effect of the transgene and the trade-offs in epidemiological traits, highlighting the need for detailed quantitative data to understand more fully the impact of mosquito transgenesis on dengue virulence. Dengue virulence in mosquitoes can be selected on by transgenic strategies of blocking transmission, decreased mosquito biting, increased mosquito background mortality, and increased mosquito infection-induced mortality. Our results suggest that dengue control strategies that raise mosquito background mortality or mosquito infection-induced mortality pose less risk of causing increased virulence to humans than strategies that block transmission or reduce mosquito biting.

  13. The resistance map of Aedes aegypti (Linn. to cypermethrin and malathion in Central Java

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    Bina Ikawati

    2015-06-01

    Full Text Available The increasing prevalence of Dengue Haemmorhaegic Fever (DHF is spread through all districts in Indonesia. Dengue Haemorrhagic Fever Control such as vector control, focussing to break DHF transmission. Some research about Ae. aegypti resistance had been done in DHF endemic area in Central Java. Resistance status of Ae. aegypti against insecticide programme promoted by health government in middle and low endemic DHF in Central Java was investigated in this research. Sample collected from 100 houses selected purposively in every village, at every District there were 3 villages selected. Samples consisted of egg, larvae and adult mosquitoes of Ae. aegypti, and reared to get F1. Resistance test of Ae. aegypti done by using WHO susceptibility impregnated paper test procedure. This research showed that Ae. aegypti in all research location had been resistance to malathion 0.8% with mosquitoes mortality average between 13.80%-61.67% and almost all sample is resistance to cypermethrin 0.05% with mosquitoes mortality between 10.00%-63.33% except with sample from Banjarnegara District which has mosquitoes mortality of 84.20%. The conclusion of this research is that Ae. aegypti in all research location had been resistance to malathion. Almost all location resistant to cypermethrin except Banjarnegara District sample which has tolerance level.

  14. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus Programa de computador para reconhecimento da larva de Aedes aegypti e Aedes albopictus

    OpenAIRE

    André Iwersen de São Thiago; Emil Kupek; Joaquim Alves Ferreira Neto; Paulo de Tarso São Thiago

    2002-01-01

    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...

  15. Metallic copper spray--a new control technique to combat invasive container-inhabiting mosquitoes.

    Science.gov (United States)

    Becker, Norbert; Oo, Thin Thin; Schork, Nino

    2015-11-09

    The control of container-inhabiting mosquitoes is mainly based on environmental management with special emphasis on community participation e.g. source reduction by elimination or modification of water bodies. However, citizens are often not aware of the problems related to urban mosquito control or just ignore the advice provided during anti-mosquito control campaigns. In particular, cemeteries contain favourite breeding sites for container-inhabiting mosquitoes like Ochlerotatus j. japonicus, Culex pipiens s.l./Cx. torrentium, Aedes aegypti or Aedes albopictus. In our study, we investigated whether metallic copper e.g. in form of copper spray can be a suitable and cost-effective tool to combat mosquito breeding in vases or other similar small containers where no commonly used insecticides can be applied. The effect of metallic copper spray in comparison to 5 Euro cent coins or copper tubes at different dosages and water qualities applied in small water collections such as widely used plastic grave vases were evaluated by assessing the mortality rates of larvae of Oc.j. japonicus, Cx. pipiens s.l./Cx. torrentium and Ae.aegypti. Different water qualities were tested to assess the influence of pH on the solubility of the copper ions. The copper concentrations were quantified using ICP/MS (Inductively coupled plasma/Mass spectrometry) in relation to the exposure time and mortality rates of mosquito larvae. All statistical analyses were computed using JMP 10.0.2 (SAS Institute Inc., 2012, Cary, NC, USA). Dosages of less than 500 ppb of copper in the water of small containers led to a 100% mortality rate after 2 weeks for all tested mosquito species by using one or more 5 Euro cent coins/vase. When the interior surface of plastic grave vases was covered by metallic copper spray, all of the tested larvae died after 7-10 days in the laboratory and under field conditions the reduction rate was 99.44% for Oc.j. japonicus and 99.6% for Culex pipiens s.l./Cx. torrentium

  16. Co-breeding Association of Aedes albopictus (Skuse) and Aedes aegypti (Linnaeus) (Diptera: Culicidae) in Relation to Location and Container Size.

    Science.gov (United States)

    Hashim, Nur Aida; Ahmad, Abu Hassan; Talib, Anita; Athaillah, Farida; Krishnan, Kumara Thevan

    2018-03-01

    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.

  17. Toxicity of insecticides to Toxorhynchites splendens and three vector mosquitos and their sublethal effect on biocontrol potential of the predator.

    Science.gov (United States)

    Amalraj, D D; Das, P K

    1996-03-01

    Toxicity of six larvicides ie fenthion, temephos, malathion, deltamethrin, alphamethrin (Fendona), OMS 3031 and five adulticides ie malathion, fenitrothion, propoxur, deltamethrin, permethrin to Aedes aegypti, Culex quiquefasciatus, Anopheles stephensi and the predator, Toxorhynchites splendens was studied for evaluating safety margin. Concentrations of alphamethrin that killed 50% larvae of T. splendens were 53 and 12 times more than that which killed Cx. quinquefasciatus and Ae. aegypti. In case of deltamethrin, concentrations required to kill 50% larvae of T. splendens were 14 and 5 times more than that required against other two species. Other larvicides tested were equally toxic to both T. splendens and vector mosquitos. There was no significant difference in the toxicity of larvicides to T. splendens and An. stephensi. Deltamethrin was 25-132 times less toxic to adults of T. splendens in comparison to vector mosquitos. For other adulticides the range was 1-10. Immature developmental time of T. splendens was not affected by any of the insecticides tested. However, predation rate was lowered when larvae of Ae. aegypti previously exposed to fenthion and temephos were offered. Whereas, alphamethrin and OMS 3031 did not affect the feeding rate of the predator. There was a significant reduction in the pupal weight and pupation as a result of the predator feeding on the insecticide treated prey. There was a significant negative relationship between rate of pupation and dosage. The present study indicates that synthetic pyrethroids owing to their higher safety margin can be used in an integrated vector management program.

  18. Vector Competence of Aedes aegypti and Aedes polynesiensis Populations from French Polynesia for Chikungunya Virus.

    Directory of Open Access Journals (Sweden)

    Vaea Richard

    2016-05-01

    Full Text Available From October 2014 to March 2015, French Polynesia experienced for the first time a chikungunya outbreak. Two Aedes mosquitoes may have contributed to chikungunya virus (CHIKV transmission in French Polynesia: the worldwide distributed Ae. aegypti and the Polynesian islands-endemic Ae. polynesiensis mosquito.To investigate the vector competence of French Polynesian populations of Ae. aegypti and Ae. polynesiensis for CHIKV, mosquitoes were exposed per os at viral titers of 7 logs tissue culture infectious dose 50%. At 2, 6, 9, 14 and 21 days post-infection (dpi, saliva was collected from each mosquito and inoculated onto C6/36 mosquito cells to check for the presence of CHIKV infectious particles. Legs and body (thorax and abdomen of each mosquito were also collected at the different dpi and submitted separately to viral RNA extraction and CHIKV real-time RT-PCR.CHIKV infection rate, dissemination and transmission efficiencies ranged from 7-90%, 18-78% and 5-53% respectively for Ae. aegypti and from 39-41%, 3-17% and 0-14% respectively for Ae. polynesiensis, depending on the dpi. Infectious saliva was found as early as 2 dpi for Ae. aegypti and from 6 dpi for Ae. polynesiensis. Our laboratory results confirm that the French Polynesian population of Ae. aegypti is highly competent for CHIKV and they provide clear evidence for Ae. polynesiensis to act as an efficient CHIKV vector.As supported by our findings, the presence of two CHIKV competent vectors in French Polynesia certainly contributed to enabling this virus to quickly disseminate from the urban/peri-urban areas colonized by Ae. aegypti to the most remote atolls where Ae. polynesiensis is predominating. Ae. polynesiensis was probably involved in the recent chikungunya outbreaks in Samoa and the Cook Islands. Moreover, this vector may contribute to the risk for CHIKV to emerge in other Polynesian islands like Fiji, and more particularly Wallis where there is no Ae. aegypti.

  19. Population Dynamics of Aedes aegypti and Dengue as Influenced by Weather and Human Behavior in San Juan, Puerto Rico

    Science.gov (United States)

    Barrera, Roberto; Amador, Manuel; MacKay, Andrew J.

    2011-01-01

    Previous studies on the influence of weather on Aedes aegypti dynamics in Puerto Rico suggested that rainfall was a significant driver of immature mosquito populations and dengue incidence, but mostly in the drier areas of the island. We conducted a longitudinal study of Ae. aegypti in two neighborhoods of the metropolitan area of San Juan city, Puerto Rico where rainfall is more uniformly distributed throughout the year. We assessed the impacts of rainfall, temperature, and human activities on the temporal dynamics of adult Ae. aegypti and oviposition. Changes in adult mosquitoes were monitored with BG-Sentinel traps and oviposition activity with CDC enhanced ovitraps. Pupal surveys were conducted during the drier and wetter parts of the year in both neighborhoods to determine the contribution of humans and rains to mosquito production. Mosquito dynamics in each neighborhood was compared with dengue incidence in their respective municipalities during the study. Our results showed that: 1. Most pupae were produced in containers managed by people, which explains the prevalence of adult mosquitoes at times when rainfall was scant; 2. Water meters were documented for the first time as productive habitats for Ae. aegypti; 3. Even though Puerto Rico has a reliable supply of tap water and an active tire recycling program, water storage containers and discarded tires were important mosquito producers; 4. Peaks in mosquito density preceded maximum dengue incidence; and 5. Ae. aegypti dynamics were driven by weather and human activity and oviposition was significantly correlated with dengue incidence. PMID:22206021

  20. Mosquitoes rely on their gut microbiota for development

    Science.gov (United States)

    Coon, Kerri L.; Vogel, Kevin J.; Brown, Mark R.; Strand, Michael R.

    2014-01-01

    Field studies indicate adult mosquitoes (Culicidae) host low diversity communities of bacteria that vary greatly among individuals and species. In contrast, it remains unclear how adult mosquitoes acquire their microbiome, what influences community structure, and whether the microbiome is important for survival. Here we used pyrosequencing of 16S rRNA to characterize the bacterial communities of three mosquito species reared under identical conditions. Two of these species, Aedes aegypti and Anopheles gambiae, are anautogenous and must blood feed to produce eggs, while one, Georgecraigius atropalpus, is autogenous and produces eggs without blood feeding. Each mosquito species contained a low diversity community comprised primarily of aerobic bacteria acquired primarily from the aquatic habitat in which larvae developed. Our results suggested the communities in Ae. aegypti and An. gambiae larvae share more similarities with one another than with Ge. atropalpus. Studies with Ae. aegypti also strongly suggested that adults transstadially acquired several members of the larval bacterial community, but only four genera of bacteria present in blood fed females were detected on eggs. Functional assays showed that axenic larvae of each species failed to develop beyond the first instar. Experiments with Ae. aegypti indicated several members of the microbial community and Escherichia coli successfully colonized axenic larvae and rescued development. Overall, our results provide new insights about the acquisition and structure of bacterial communities in mosquitoes. They also indicate three mosquito species spanning the breadth of the Culicidae depend on their gut microbiome for development. PMID:24766707

  1. Guppies as predators of common mosquito larvae in Malaysia.

    Science.gov (United States)

    Saleeza, S N R; Norma-Rashid, Y; Sofian-Azirun, M

    2014-03-01

    Observation on predation activities of guppies (Poecilia reticulata) on the larvae of three species of mosquito, namely Aedes albopictus, Aedes aegypti, and Culex quinquefasciatus was carried out under laboratory conditions. Male and female guppies were used as predators for predation experiments on the 4th instars of mosquito larvae. The daily feeding rates comparing male and female guppies on mosquito larvae were different; the female guppies consumed more mosquito larvae than male guppies did. The daily feeding rates of female guppies were 121.3 for Ae. aegypti, 105.6 for Ae. albopictus, and 72.3 for Cx. quinquefasciatus. The daily feeding rates of male guppies were 98.6 for Ae. aegypti, 73.6 for Ae. albopictus, and 47.6 for Cx. quinquefasciatus. In terms of prey preference, there was greater preference towards mosquito larvae of Ae. aegypti, followed by Ae. albopictus, and the least preferred was Cx. quinquefasciatus. Male and female guppies consumed more mosquito larvae during lights on (day time) compared with lights off (night time). The water volume, prey species, number of fish predators available, prey densities, and prey's sex also influenced the predation activities.

  2. Effects of Toxorhynchites moctezuma larval predation on Aedes aegypti populations: experimental evaluation.

    Science.gov (United States)

    Tikasingh, E S

    1992-07-01

    Predatory larvae of the mosquito Toxorhynchites moctezuma were used experimentally to control a standing crop of larvae of the dengue vector mosquito Ae.aegypti. Each week, fifty Ae.aegypti first instar larvae were introduced to each of five water-filled drums (220 litres) of the type commonly used for domestic water storage in Caribbean dwellings. At the beginning of the fourth week, a certain number (0, 1, 2, 5 or 10) of first instar Tx.moctezuma larvae were introduced to each drum and the daily yield of Ae.aegypti adults from each drum was monitored thereafter. The experiment was repeated three times. With only one or two Tx.moctezuma larvae, predation on Ae.aegypti larvae stopped the output of Ae.aegypti adults for 1 week. Five or ten Tx.moctezuma prevented any Ae.aegypti emergence for up to 16 weeks. Cannibalism among Tx.moctezuma larvae was seldom observed and appeared not to be a hindrance in using this species against Ae.aegypti. Thus Tx.moctezuma is regarded as a good candidate for the biological control of Ae.aegypti by augmentative releases.

  3. Caracterização das respostas transcricionais e microbiomas de populações naturais do mosquito Aedes aegypti com diferentes níveis de suscetibilidade ao vírus dengue

    OpenAIRE

    Dreyer, Carine Spenassatto [UNESP

    2015-01-01

    Dengue is the arbovirosis of greater growth in recent years, reflecting on social and economic impacts due to the high morbidity and mortality rates triggered by infection. Dengue has Aedes aegypti as its primary vector, which is distributed throughout tropical and subtropical regions of the planet. Due to its anthropophilic and haematophagic habit, rapid development and specific behavioral characteristics, it is an excellent dengue virus transmitter. Control measurements are restricted to el...

  4. History of Aedes mosquitoes in Hawaii.

    Science.gov (United States)

    Winchester, Jonathan C; Kapan, Durrell D

    2013-06-01

    As a geographically isolated island chain with no native mosquitoes, Hawaii is a model for examining the mechanisms behind insect vector invasions and their subsequent interactions with each other and with human populations. The yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Ae. albopictus, have been responsible for epidemics of dengue in Hawaii. As one of the world's earliest locations to be invaded by both species, Hawaii's history is particularly relevant because both species are currently invading new areas worldwide and are implicated in outbreaks of emergent or reemergent pathogens such as dengue, chikungunya, and yellow fever. Here we analyze the historical records of mosquito introductions in order to understand the factors that have led to the current distribution of these 2 mosquitoes in the Hawaiian Islands.

  5. A role for endosomal proteins in alphavirus dissemination in mosquitoes

    Science.gov (United States)

    Campbell, Corey L.; Lehmann, Christopher J.; Gill, Sargeet S.; Dunn, W. A.; James, Anthony A.; Foy, Brian D.

    2011-01-01

    Little is known about endosomal pathway proteins involved in arthropod-borne virus (arbovirus) assembly and cell-to-cell spread in vector mosquitoes. UNC93A and Synaptic vesicle-2 (SV2) proteins are involved in intracellular transport in mammals. They show amino acid sequence conservation from mosquitoes to humans, and their transcripts are highly-enriched in Aedes aegypti during arbovirus infection. Transient gene silencing of SV2 or UNC93A in mosquitoes infected with the recombinant alphavirus Sindbis MRE16-eGFP (SINV; family Togaviridae) resulted in the accumulation of viral positive- and negative-strand RNA, congregation of virus envelope antigen in intracellular networks, and reduced virus dissemination outside of the midgut. Further, UNC93A silencing, but not SV2 silencing, resulted in a 10-fold reduction in viral titers at 4 days post-infection. Together, these data support a role for UNC93A and SV2 in virus assembly or budding. Cis-regulatory elements (CREs) were identified at the 5′-ends of genes from the original dataset in which SV2 and UNC93A were identified. Common CREs at the 5′-end genomic regions of a subset of enriched transcripts support the hypothesis that UNC93A transcription may be co-regulated with that of other ion transport and endosomal trafficking proteins. PMID:21496127

  6. Potential of turmeric rhizome essential oils against Aedes aegypti larvae

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    Roselina Panghiyangani

    2012-04-01

    Full Text Available BACKGROUND Dengue hemorrhagic fever (DHF has long been a serious health problem in Indonesia, including Kalimantan (Borneo, as is evident from the increased case fatality rate in Banjarbaru city. Synthetic chemical insecticides have frequently been used to eradicate mosquitoes, but are toxic to the body and resistance of adult and larvae mosquito Aedes aegypti has been reported. The present study aims to assess the effect of essential oils of turmeric rhizomes (Curcuma domestica Val against Aedes aegypti larvae Methods This was an experimental study of post test one group design, performed in two phases, using Aedes aegypti larvae as test organisms. In the first phase, laboratory-reared larvae were used for calculation of the LC50 and LC90, while in the second phase the test organisms were larvae taken from 75 buildings that had been designated based on a preliminary survey in four sub-districts in Banjarbaru city with a high incidence of dengue cases. Probit analysis of was used to calculate LC50 and LC90, and the Kruskal-Wallis test to determine the larvicidal potency of turmeric rhizome essential oils. Results This study demonstrates that turmeric rhizome essential oils effectively killed laboratory-reared Aedes aegypti larvae at an LC50 of 9.239 ppm and an LC90 of 13.565 ppm. The effectiveness of the essential oils of turmeric rhizomes (Curcuma domestica Val. for killing Aedes aegypti larvae in residential areas was 68%. Conclusion Turmeric (Curcuma domestica Val. rhizome essential oils can kill Aedes aegypti larvae, are environment friendly and can be used for the control of mosquitoes.

  7. Experimental Transmission of Mayaro Virus by Aedes aegypti

    OpenAIRE

    Long, Kanya C.; Ziegler, Sarah A.; Thangamani, Saravanan; Hausser, Nicole L.; Kochel, Tadeusz J.; Higgs, Stephen; Tesh, Robert B.

    2011-01-01

    Outbreaks of Mayaro fever have been associated with a sylvatic cycle of Mayaro virus (MAYV) transmission in South America. To evaluate the potential for a common urban mosquito to transmit MAYV, laboratory vector competence studies were performed with Aedes aegypti from Iquitos, Peru. Oral infection in Ae. aegypti ranged from 0% (0/31) to 84% (31/37), with blood meal virus titers between 3.4 log10 and 7.3 log10 plaque-forming units (PFU)/mL. Transmission of MAYV by 70% (21/30) of infected mos...

  8. Characterization and productivity profiles of Aedes aegypti (L.) breeding habitats across rural and urban landscapes in western and coastal Kenya.

    Science.gov (United States)

    Ngugi, Harun N; Mutuku, Francis M; Ndenga, Bryson A; Musunzaji, Peter S; Mbakaya, Joel O; Aswani, Peter; Irungu, Lucy W; Mukoko, Dunstan; Vulule, John; Kitron, Uriel; LaBeaud, Angelle D

    2017-07-12

    Aedes aegypti, the principal vector for dengue and other emerging arboviruses, breeds preferentially in various man-made and natural container habitats. In the absence of vaccine, epidemiological surveillance and vector control remain the best practices for preventing dengue outbreaks. Effective vector control depends on a good understanding of larval and adult vector ecology of which little is known in Kenya. In the current study, we sought to characterize breeding habitats and establish container productivity profiles of Ae. aegypti in rural and urban sites in western and coastal Kenya. Twenty sentinel houses in each of four study sites (in western and coastal Kenya) were assessed for immature mosquito infestation once a month for a period of 24 months (June 2014 to May 2016). All water-holding containers in and around the households were inspected for Ae. aegypti larvae and pupae. Collections were made from a total of 22,144 container visits: Chulaimbo (7575) and Kisumu (8003) in the west, and from Msambweni (3199) and Ukunda (3367) on the coast. Of these, only 4-5.6% were positive for Ae. aegypti immatures. In all four sites, significantly more positive containers were located outdoors than indoors. A total of 17,537 Ae. aegypti immatures were sampled from 10 container types. The most important habitat types were buckets, drums, tires, and pots, which produced over 75% of all the pupae. Key outdoor containers in the coast were buckets, drums and tires, which accounted for 82% of the pupae, while pots and tires were the only key containers in the western region producing 70% of the pupae. Drums, buckets and pots were the key indoor containers, producing nearly all of the pupae in the coastal sites. No pupae were collected indoors in the western region. The coastal region produced significantly more Ae. aegypti immatures than the western region both inside and outside the sentinel houses. These results indicate that productive Ae. aegypti larval habitats are

  9. Vector Competence of French Polynesian Aedes aegypti and Aedes polynesiensis for Zika Virus.

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    Vaea Richard

    2016-09-01

    Full Text Available In 2013-2014, French Polynesia experienced for the first time a Zika outbreak. Two Aedes mosquitoes may have contributed to Zika virus (ZIKV transmission in French Polynesia: the worldwide distributed Ae. aegypti and the Polynesian islands-endemic Ae. polynesiensis mosquito.To evaluate their vector competence for ZIKV, mosquitoes were infected per os at viral titers of 7 logs tissue culture infectious dose 50%. At several days post-infection (dpi, saliva was collected from each mosquito and inoculated onto C6/36 mosquito cells to check for the presence of ZIKV infectious particles. Legs and body of each mosquito were also collected and submitted separately to RNA extraction and ZIKV RT-PCR. In Ae. aegypti the infection rate was high as early as 6 dpi and the dissemination efficiency get substantial from 9 dpi while the both rates remained quite low in Ae. polynesiensis. The transmission efficiency was poor in Ae. aegypti until 14 dpi and no infectious saliva was found in Ae. polynesiensis at the time points studied.In our experimental conditions, the late ability of the French Polynesian Ae. aegypti to transmit ZIKV added by the poor competence of Ae. polynesiensis for this virus suggest the possible contribution of another vector for the propagation of ZIKV during the outbreak, in particular in remote islands where Ae. polynesiensis is predominating.

  10. Rapid and non-destructive detection and identification two strains of Wolbachia in Aedes aegypti by near-infrared spectroscopy

    Science.gov (United States)

    We investigated the potential of using near-infrared spectroscopy (NIRS) to detect the presence of Wolbachia pipientis (wMel) in male and female laboratory-reared Aedes aegypti mosquitoes. The release of Wolbachia transinfected mosquitoes is likely to form a key component of disease control strategi...

  11. Vector competence of Brazilian Aedes aegypti and Ae. albopictus for a Brazilian yellow fever virus isolate.

    Science.gov (United States)

    Johnson, Barbara W; Chambers, Trudy V; Crabtree, Mary B; Filippis, Ana M B; Vilarinhos, Paulo T R; Resende, Marcelo C; Macoris, Maria de Lourdes G; Miller, Barry R

    2002-01-01

    Because the potential urban yellow fever (YF) mosquito vectors Aedes aegypti and Ae. albopictus are at historical highs in Brazil, both in terms of density and geographical range, we assessed the risk of an urban YF epidemic in Brazil. We evaluated and confirmed in a laboratory setting the vector competence of Brazilian Ae. aegypti for a currently circulating strain of YF virus, and investigated the potential for Brazilian Ae. albopictus to transmit YF.

  12. Analysis of cycle Gene Expression in Aedes aegypti Brains by In Situ Hybridization

    OpenAIRE

    Chahad-Ehlers, Samira; Gentile, Carla; Lima, Jos? Bento Pereira; Peixoto, Alexandre Afranio; Bruno, Rafaela Vieira

    2013-01-01

    Even though the blood-sucking mosquito Aedes aegypti is one of the most important disease vectors, relatively little is known about the molecular mechanisms underlying processes involved in the temporal pattern of its activity and host seeking behavior. In this study, we analyzed the expression of the cycle (cyc) gene, one of the core components of the circadian clock, in Ae. aegypti brains by in situ hybridization at two different time points in light-dark conditions and compared the results...

  13. Suppression of Aedes aegypti by predatory Toxorhynchites moctezuma in an island habitat.

    Science.gov (United States)

    Tikasingh, E S; Eustace, A

    1992-07-01

    Larval populations of the mosquito Aedes aegypti were suppressed by predatory Toxorhynchites moctezuma mosquito larvae released systematically in a village on Union Island (Saint Vincent and the Grenadines) during March-December 1988. Eggs and larvae of Tx.moctezuma were transported from Trinidad and introduced into all semi-permanent and permanent water-holding containers in the experimental village at Clifton. The semi-isolated village of Ashton served as control. Base-line Ae.aegypti indices (house, ovitrap, Breteau, cistern/tank, drum/barrel, small containers) were obtained for the two villages over a 4-month period prior to the introduction of the predatory Tx.moctezuma mosquito larvae. After sustained releases of predators for 5 months, all indices of Ae.aegypti were lower in the treated village than in the untreated village during the last 3 months of the year.

  14. Mosquito repellent activity of volatile oils from selected aromatic plants.

    Science.gov (United States)

    Lalthazuali; Mathew, Nisha

    2017-02-01

    Essential oils from fresh leaves of four aromatic plants viz., Ocimum sanctum, Mentha piperita, Eucalyptus globulus and Plectranthus amboinicus were extracted by hydrodistillation. The test solutions were prepared as 20% essential oil in ethanol and positive control as 20% DEET in ethanol. Essential oil blend was prepared as 5% concentration. Nulliparous, 3-5-day-old female adult Aedes aegypti mosquitoes were used for repellency screening as per ICMR protocol. The study showed that the repellency of 20% essential oil of O. sanctum, M. piperita and P. amboinicus were comparable with that of the standard DEET (20%) as no mosquito landing on the test was observed up to 6 h. The E. globulus oil exhibited mosquito repellency only upto 1½ h. Considerable mosquito landing and feeding was displayed in negative control. In the case of the oil blend, no landing of mosquitoes was seen up to 6 h as that of positive control. The results showed that the essential oil blend from O. sanctum, M. piperita, E. globulus and P. amboinicus could repel Ae. aegypti mosquitoes or prevent from feeding as in the case of DEET even at a lower concentration of 5%. This study demonstrates the potential of essential oils from O. sanctum, M. piperita, E. globulus and P. amboinicus and their blend as mosquito repellents against Ae. aegypti, the vector of dengue, chikungunya and yellow fever.

  15. Feasible introgression of an anti-pathogen transgene into an urban mosquito population without using gene-drive.

    Directory of Open Access Journals (Sweden)

    Kenichi W Okamoto

    2014-07-01

    Full Text Available Introgressing anti-pathogen constructs into wild vector populations could reduce disease transmission. It is generally assumed that such introgression would require linking an anti-pathogen gene with a selfish genetic element or similar technologies. Yet none of the proposed transgenic anti-pathogen gene-drive mechanisms are likely to be implemented as public health measures in the near future. Thus, much attention now focuses instead on transgenic strategies aimed at mosquito population suppression, an approach generally perceived to be practical. By contrast, aiming to replace vector competent mosquito populations with vector incompetent populations by releasing mosquitoes carrying a single anti-pathogen gene without a gene-drive mechanism is widely considered impractical.Here we use Skeeter Buster, a previously published stochastic, spatially explicit model of Aedes aegypti to investigate whether a number of approaches for releasing mosquitoes with only an anti-pathogen construct would be efficient and effective in the tropical city of Iquitos, Peru. To assess the performance of such releases using realistic release numbers, we compare the transient and long-term effects of this strategy with two other genetic control strategies that have been developed in Ae. aegypti: release of a strain with female-specific lethality, and a strain with both female-specific lethality and an anti-pathogen gene. We find that releasing mosquitoes carrying only an anti-pathogen construct can substantially decrease vector competence of a natural population, even at release ratios well below that required for the two currently feasible alternatives that rely on population reduction. Finally, although current genetic control strategies based on population reduction are compromised by immigration of wild-type mosquitoes, releasing mosquitoes carrying only an anti-pathogen gene is considerably more robust to such immigration.Contrary to the widely held view that

  16. Larvicidal activity of leguminous seeds and grains against Aedes aegypti and Culex pipiens pallens.

    Science.gov (United States)

    Jang, Young-Su; Baek, Bong-Rae; Yang, Young-Cheol; Kim, Moo-Key; Lee, Hoi-Seon

    2002-09-01

    Larvicidal activity of methanol extracts of 26 leguminous seeds and 20 grains against early 4th-stage larvae of Aedes aegypti and Culex pipiens pallens was examined. At 200 ppm of the extracts from Cassia obtusifolia, Cassia tora, and Vicia tetrasperma, more than 90% mortality was obtained in larvae of Ae. aegypti and Cx. pipiens pallens. Extract of C. tora gave 86.7 and 100% mortality in the larvae of Ae. aegypti and Cx. pipiens pallens at 40 ppm but 59.2 and 78.3% mortality against larvae of Ae. aegypti and Cx. pipiens pallens at 20 ppm, respectively. At 40 ppm, extract of C. obtusifolia caused 51.4 and 68.5% mortality of the 4th-stage larvae of Ae. aegypti and Cx. pipiens pallens, respectively. Larvicidal activity of extract of C obtusifolia was significantly reduced when used at 20 ppm. Further studies of these plants as possible agents for mosquito control are warranted.

  17. Occurrence of Toxorhynchites guadeloupensis (Dyar Knab) in oviposition trap of Aedes aegypti (L.) (Diptera: Culicidae).

    Science.gov (United States)

    Honório, Nildimar A; de Barros, Fábio S M; Tsouris, Pantelis; Rosa-Freitas, Maria G

    2007-01-01

    Toxorhynchites guadeloupensis (Dyar 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.

  18. Occurrence of Toxorhynchites guadeloupensis (Dyar and Knab) in oviposition trap of Aedes aegypti (L.) (Diptera: Culicidae)

    Energy Technology Data Exchange (ETDEWEB)

    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: maria@freitas-tsouris.com

    2007-09-15

    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)

  19. Occurrence of Toxorhynchites guadeloupensis (Dyar and Knab) in oviposition trap of Aedes aegypti (L.) (Diptera: Culicidae)

    International Nuclear Information System (INIS)

    Honorio, Nildimar A.

    2007-01-01

    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)

  20. Effects of insemination and blood-feeding on locomotor activity of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) females under laboratory conditions

    OpenAIRE

    Lima-Camara, Tamara N; Lima, José B P; Bruno, Rafaela V; Peixoto, Alexandre A

    2014-01-01

    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...

  1. The RNA interference pathway affects midgut infection- and escape barriers for Sindbis virus in Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Olson Ken E

    2010-04-01

    Full Text Available Abstract Background The RNA interference (RNAi pathway acts as an innate antiviral immune response in Aedes aegypti, modulating arbovirus infection of mosquitoes. Sindbis virus (SINV; family: Togaviridae, genus: Alphavirus is an arbovirus that infects Ae. aegypti in the laboratory. SINV strain TR339 encounters a midgut escape barrier (MEB during infection of Ae. aegypti. The nature of this barrier is not well understood. To investigate the role of the midgut as the central organ determining vector competence for arboviruses, we generated transgenic mosquitoes in which the RNAi pathway was impaired in midgut tissue of bloodfed females. We used these mosquitoes to reveal effects of RNAi impairment in the midgut on SINV replication, midgut infection and dissemination efficiencies, and mosquito longevity. Results As a novel tool for studying arbovirus-mosquito interactions, we engineered a transgenic mosquito line with an impaired RNAi pathway in the midgut of bloodfed females by silencing expression of the Aa-dcr2 gene. In midgut tissue of the transgenic Carb/dcr16 line, Aa-dcr2 expression was reduced ~50% between 1-7 days post-bloodmeal (pbm when compared to the recipient mosquito strain. After infection with SINV-TR339EGFP, Aa-dcr2 expression levels were enhanced in both mosquito strains. In the RNAi pathway impaired mosquito strain SINV titers and midgut infection rates were significantly higher at 7 days pbm. There was also a strong tendency for increased virus dissemination rates among the transgenic mosquitoes. Between 7-14 days pbm, SINV was diminished in midgut tissue of the transgenic mosquitoes. Transgenic impairment of the RNAi pathway and/or SINV infection did not affect longevity of the mosquitoes. Conclusions We showed that RNAi impaired transgenic mosquitoes are a useful tool for studying arbovirus-mosquito interactions at the molecular level. Following ingestion by Ae. aegypti, the recombinant SINV-TR339EGFP was confronted with both

  2. Determinasi Strain Aedes aegypti (Linn. yang Rentan Homozigot dengan Metode Seleksi Indukan Tunggal

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    Isfanda Isfanda

    2017-06-01

    Full Text Available Abstract. Aedes aegypti is a type of mosquito that can carry dengue virus, yellow fever and chikunguya. The spread of this mosquito is very broad, covering almost all tropical regions worldwide. This study aims to determine the vulnerability status of homozygous Ae. aegypti. Sample of Ae. aegypti is mosquito strain from Health Entomology Laboratory Bogor Institute of Agriculture and at random sampling. Ae. aegypti eggs which comes from the breeders hatched separately. Insecticide‐treated paper (impregnated paper malathion, bendiokarb and deltamethrin are use for insecticides testing using WHO test kit. The analysis showed that the mosquito Ae. aegypti tested with a single sib‐selection method and were exposed to the insecticide malathion, propoksur, and showed an increasing trend sipermetrin vulnerability homozygous at each generation. As for the fourth generation (F4 has not shown changes into a strain that is homozygous susceptible to three types of insecticides. The formation of homozygous susceptible strains take over five generations.Keywords: Ae. aegypti, malathion, bendiocarb, deltamethrin, single sib‐selection methodAbstrak. Aedes aegypti merupakan jenis nyamuk yang dapat membawa virus dengue, demam kuning (yellow fever dan chikunguya. Penyebaran nyamuk ini sangat luas, meliputi hampir semua daerah tropis di seluruh dunia. Penelitian ini bertujuan mengetahui status kerentanan nyamuk Ae. aegypti secara homozigot. Nyamuk Ae. aegypti yang dijadikan sampel yaitu nyamuk dewasa strain yang ada di Laboratorium Entomologi Kesehatan Institut Pertanian Bogor dan diambil secara acak. Telur Ae. aegypti yang berasal dari satu indukan ditetaskan secara terpisah. Insektisida yang digunakan untuk pengujian menggunakan kertas berinsektisida (impregnated paper malation, bendiokarb, dan deltametrin dengan menggunakan WHO test kit. Hasil analisis menunjukkan bahwa nyamuk Ae. aegypti yang diuji dengan metode seleksi indukan tunggal serta dipaparkan

  3. Aedes aegypti on Madeira Island (Portugal): genetic variation of a recently introduced dengue vector.

    Science.gov (United States)

    Seixas, Gonçalo; Salgueiro, Patrícia; Silva, Ana Clara; Campos, Melina; Spenassatto, Carine; Reyes-Lugo, Matías; Novo, Maria Teresa; Ribolla, Paulo Eduardo Martins; Silva Pinto, João Pedro Soares da; Sousa, Carla Alexandra

    2013-01-01

    The increasing population of Aedes aegypti mosquitoes on Madeira Island (Portugal) resulted in the first autochthonous dengue outbreak, which occurred in October 2012. Our study establishes the first genetic evaluation based on the mitochondrial DNA (mtDNA) genes [cytochrome oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4)] and knockdown resistance (kdr) mutations exploring the colonisation history and the genetic diversity of this insular vector population. We included mosquito populations from Brazil and Venezuela in the analysis as putative geographic sources. The Ae. aegypti population from Madeira showed extremely low mtDNA genetic variability, with a single haplotype for COI and ND4. We also detected the presence of two important kdr mutations and the quasi-fixation of one of these mutations (F1534C). These results are consistent with a unique recent founder event that occurred on the island of Ae. aegypti mosquitoes that carry kdr mutations associated with insecticide resistance. Finally, we also report the presence of the F1534C kdr mutation in the Brazil and Venezuela populations. To our knowledge, this is the first time this mutation has been found in South American Ae. aegypti mosquitoes. Given the present risk of Ae. aegypti re-invading continental Europe from Madeira and the recent dengue outbreaks on the island, this information is important to plan surveillance and control measures.

  4. [New record of Aedes aegypti (Linnaeus, 1762), in the urban area of La Pedrera, Amazonas, Colombia].

    Science.gov (United States)

    Rojas-Gil, Yesika; Brochero, Helena

    2008-12-01

    Before 2005, Aedes aegypti had not been recorded in the Colombian province of Amazonas. Because this species has been increasing its range throughout Colombia, an entomological surveillance program has been routinely directed toward detecting it presence in Amazonas by the Amazonas State Health Authority. Surveillance data were used as the basis for recording Aedes aegypti in Amazonas Province. Household surveys of Ae. aegypti larvae were conducted by trained personnel belonging to the Amazonas State Health Authority. The following standard larval indices were estimated: house index (HI)--the percentage of premises with positive containers, the container index (CI)--the percentage of positive containers among the water-holding containers, and the Breteau index (BI)--the number of positive containers per 100 premises. Residents were questioned concerning their perception of mosquito presence in their houses. Subsequently, control activities were undertaken to reduce the mosquito's infestation. Aedes aegypti was found in the urban area of the village of La Pedrera. During the first household survey, the indices were HI=29.6%, CI=9.0% and, BI=40.8%. After control activities, these values decreased; however, elimination of the infestation was not possible in this geographical area. The community recognizes the mosquito immature forms in water containers in houses and associated them as vectors of several diseases. The presence of Ae. aegypti mosquitoes in the village La Pedrera was verified. Aedes albopictus was not found in this area.

  5. Aedes aegypti salivary gland extract ameliorates experimental inflammatory bowel disease.

    Science.gov (United States)

    Sales-Campos, Helioswilton; de Souza, Patricia Reis; Basso, Paulo José; Ramos, Anderson Daniel; Nardini, Viviani; Chica, Javier Emílio Lazo; Capurro, Margareth Lara; Sá-Nunes, Anderson; de Barros Cardoso, Cristina Ribeiro

    2015-05-01

    Current therapies for inflammatory bowel disease (IBD) are not totally effective, resulting in persistent and recurrent disease for many patients. Mosquito saliva contains immunomodulatory molecules and therein could represent a novel therapy for IBD. Here, we demonstrated the therapeutic activity of salivary gland extract (SGE) of Aedes aegypti on dextran sulfate sodium (DSS)-induced colitis. For this purpose, C57BL/6 male mice were exposed to 3% DSS in drinking water and treated with SGE at early (days 3-5) or late (days 5-8) time points, followed by euthanasia on days 6 and 9, respectively, for sample collection. The results showed an improvement in clinical disease outcome and postmortem scores after SGE treatment, accompanied by the systemic reduction in peripheral blood lymphocytes, with no impact on bone marrow and mesenteric lymph nodes cellularity or macrophages toxicity. Moreover, a local diminishment of IFN-γ, TNF-α, IL-1β and IL-5 cytokines together with a reduction in the inflammatory area were observed in the colon of SGE-treated mice. Strikingly, early treatment with SGE led to mice protection from a late DSS re-challenging, as observed by decreased clinical and postmortem scores, besides reduced circulating lymphocytes, indicating that the mosquito saliva may present components able to prevent disease relapse. Indeed, high performance liquid chromatography (HPLC) experiments pointed to a major SGE pool fraction (F3) able to ameliorate disease signs. In conclusion, SGE and its components might represent a source of important immunomodulatory molecules with promising therapeutic activity for IBD. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Shifting patterns of Aedes aegypti fine scale spatial clustering in Iquitos, Peru.

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    Genevieve LaCon

    2014-08-01

    Full Text Available Empiric evidence shows that Aedes aegypti abundance is spatially heterogeneous and that some areas and larval habitats produce more mosquitoes than others. There is a knowledge gap, however, with regards to the temporal persistence of such Ae. aegypti abundance hotspots. In this study, we used a longitudinal entomologic dataset from the city of Iquitos, Peru, to (1 quantify the spatial clustering patterns of adult Ae. aegypti and pupae counts per house, (2 determine overlap between clusters, (3 quantify the temporal stability of clusters over nine entomologic surveys spaced four months apart, and (4 quantify the extent of clustering at the household and neighborhood levels.Data from 13,662 household entomological visits performed in two Iquitos neighborhoods differing in Ae. aegypti abundance and dengue virus transmission was analyzed using global and local spatial statistics. The location and extent of Ae. aegypti pupae and adult hotspots (i.e., small groups of houses with significantly [p<0.05] high mosquito abundance were calculated for each of the 9 entomologic surveys. The extent of clustering was used to quantify the probability of finding spatially correlated populations. Our analyses indicate that Ae. aegypti distribution was highly focal (most clusters do not extend beyond 30 meters and that hotspots of high vector abundance were common on every survey date, but they were temporally unstable over the period of study.Our findings have implications for understanding Ae. aegypti distribution and for the design of surveillance and control activities relying on household-level data. In settings like Iquitos, where there is a relatively low percentage of Ae. aegypti in permanent water-holding containers, identifying and targeting key premises will be significantly challenged by shifting hotspots of Ae. aegypti infestation. Focusing efforts in large geographic areas with historically high levels of transmission may be more effective than

  7. Shifting Patterns of Aedes aegypti Fine Scale Spatial Clustering in Iquitos, Peru

    Science.gov (United States)

    LaCon, Genevieve; Morrison, Amy C.; Astete, Helvio; Stoddard, Steven T.; Paz-Soldan, Valerie A.; Elder, John P.; Halsey, Eric S.; Scott, Thomas W.; Kitron, Uriel; Vazquez-Prokopec, Gonzalo M.

    2014-01-01

    Background Empiric evidence shows that Aedes aegypti abundance is spatially heterogeneous and that some areas and larval habitats produce more mosquitoes than others. There is a knowledge gap, however, with regards to the temporal persistence of such Ae. aegypti abundance hotspots. In this study, we used a longitudinal entomologic dataset from the city of Iquitos, Peru, to (1) quantify the spatial clustering patterns of adult Ae. aegypti and pupae counts per house, (2) determine overlap between clusters, (3) quantify the temporal stability of clusters over nine entomologic surveys spaced four months apart, and (4) quantify the extent of clustering at the household and neighborhood levels. Methodologies/Principal Findings Data from 13,662 household entomological visits performed in two Iquitos neighborhoods differing in Ae. aegypti abundance and dengue virus transmission was analyzed using global and local spatial statistics. The location and extent of Ae. aegypti pupae and adult hotspots (i.e., small groups of houses with significantly [p<0.05] high mosquito abundance) were calculated for each of the 9 entomologic surveys. The extent of clustering was used to quantify the probability of finding spatially correlated populations. Our analyses indicate that Ae. aegypti distribution was highly focal (most clusters do not extend beyond 30 meters) and that hotspots of high vector abundance were common on every survey date, but they were temporally unstable over the period of study. Conclusions/Significance Our findings have implications for understanding Ae. aegypti distribution and for the design of surveillance and control activities relying on household-level data. In settings like Iquitos, where there is a relatively low percentage of Ae. aegypti in permanent water-holding containers, identifying and targeting key premises will be significantly challenged by shifting hotspots of Ae. aegypti infestation. Focusing efforts in large geographic areas with historically

  8. Cloning, genetic engineering and characterization of TMOF expressed in Saccharomyces cerevisiae to control larval mosquitoes

    Science.gov (United States)

    Trypsin modulating oostatic factor (TMOF), a decapaptide isolated from the ovaries of Aedes aegypti, is the physiological factor that terminates the trypsin biosynthesis after the blood meal. Earlier results obtained from feeding mosquito larvae and injecting female mosquitoes with TMOF show that tr...

  9. Perbedaan respon Aedes aegypti (Linnaeus) (Diptera: Culicidae), terhadap paparan anti nyamuk bakar dan bunga keluwih (Artocarpus camansi, Blanco)

    OpenAIRE

    Nur Endah Wahyuningsih; Ramauli Agustina Sihit

    2015-01-01

    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...

  10. Efficacy and safety of topical Trikatu preparation in, relieving mosquito bite reactions: a randomized controlled trial.

    Science.gov (United States)

    Maenthaisong, Ratree; Chaiyakunapruk, Nathorn; Tiyaboonchai, Waree; Tawatsin, Apiwat; Rojanawiwat, Archawin; Thavara, Usavadee

    2014-02-01

    Trikatu is composed of dried fruits of Piper nigrum L and Piper retrofractum Vahl, and dried rhizomes of Zingiber officinale R. Although this preparation has been used to relieve pruritis, pain, and inflammation for a long time, there is no clinical evidence to confirm its efficacy and safety. Therefore, we performed a double-blind, within person-randomized controlled study of 30 healthy volunteers to determine efficacy and safety of topical Trikatu on mosquito bite reactions. All subjects were bitten by Aedes aegypti laboratory mosquitoes on their forearms and they were randomly assigned arms to apply either Trikatu or reference product on the mosquito bite papule. The main outcome was the difference of papule size reduction at 30 min, measured by a caliper, between the Trikatu and reference arms. Pruritis, redness, pain, and patient satisfaction were assessed at 15, 30, 60, 180, and 360 min as secondary outcomes. There were no significant differences between treatment and reference arms on any outcome at any time of measurement. Trikatu did not show additional effects for relieving mosquito bite reaction as compared with the reference product containing camphor, menthol, and eucalyptus. For further study, it is very important to consider a proper selection of subjects, comparator product, and concentration of extract when Trikatu preparation is investigated. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Oral susceptibility of Singapore Aedes (Stegomyia aegypti (Linnaeus to Zika virus.

    Directory of Open Access Journals (Sweden)

    MeiZhi Irene Li

    Full Text Available Zika virus (ZIKV is a little known flavivirus that caused a major outbreak in 2007, in the South-western Pacific Island of Yap. It causes dengue-like syndromes but with milder symptoms. In Africa, where it was first isolated, ZIKV is mainly transmitted by sylvatic Aedes mosquitoes. The virus has also been isolated from Ae. aegypti and it is considered to be the vector involved in the urban transmission of the virus. Transmission of the virus by an African strain of Ae. aegypti has also been demonstrated under laboratory conditions. The aim of the present study is to describe the oral susceptibility of a Singapore strain of Ae. aegypti to ZIKV, under conditions that simulate local climate.To assess the receptivity of Singapore's Ae. aegypti to the virus, we orally exposed a local mosquito strain to a Ugandan strain of ZIKV. Upon exposure, fully engorged mosquitoes were maintained in an environmental chamber set at 29 °C and 70-75% RH. Eight mosquitoes were then sampled daily from day 1 to day 7, and subsequently on days 10 and 14 post exposure (pe. The virus titer of the midgut and salivary glands of each mosquito were determined using a tissue culture infectious dose(50 (TCID(50 assay. High midgut infection and salivary gland dissemination rates were observed. By day 5 after the infectious blood meal, ZIKV was found in the salivary glands of more than half of the mosquitoes tested (62%; and by day 10, all mosquitoes were potentially infective.This study showed that Singapore's urban Ae. aegypti are susceptible and are potentially capable of transmitting ZIKV. The virus could be established in Singapore should it be introduced. Nevertheless, Singapore's current dengue control strategy is applicable to control ZIKV.

  12. PEMERIKSAAN VIRUS DENGUE-3 PADA NYAMUK Aedes aegypti YANG DIINFEKSI SECARA INTRATHORAKAL DENGAN TEKNIK IMUNOSITOKIMIA MENGGUNAKAN ANTIBODI DSSE10

    Directory of Open Access Journals (Sweden)

    Dyah Widiastuti

    2013-09-01

    Full Text Available ABSTRACTDengue viruses, globally the most prevalent arboviruses, are transmitted to humans by persistently infectedAedes mosquitoes. The most important vector of Dengue virus is the mosquito Ae.aegypti, which should be the main targetof surveillance and control activities. Virologic surveillance for dengue viruses in its vector has been used as an earlywarning system to predict outbreaks. Detection of Dengue virus antigen in mosquito head squash usingimmunocytochemical streptavidin biotin peroxidase complex (SBPC assay is an alternative method for dengue vectorsurveillance. The study aimed to develope immunocytochemical SBPC assay to detect Dengue virus infection in headsquash of Ae.aegypti. The study design was experimental. Artificially-infected adult Ae. aegypti mosquitoes of DENV 3were used as infectious samples and non-infected adult Ae. aegypti mosquitoes were used as normal ones. Theimmunocytochemical SBPC assay using monoclonal antibody DSSE10 then was applied in mosquito head squash todetect Dengue virus antigen. The results were analyzed by descriptive analysis. The immunocytochemical SBPC assaycan detect Dengue virus antigen in mosquito head squash at day 2 postinfection. There are some false positive resultsfound in immunocytochemical SBPC assay.Key Word: Dengue, immunocytochemistry, DSSE10

  13. Citrus Seed Oils Efficacy against Larvae of Aedes aegypti.

    Science.gov (United States)

    Bilal, Hazrat; Akram, Waseem; Hassan, Soaib Ali; Din, Sadrud

    2017-09-01

    Dengue fever is a serious public health issue in Pakistan for many years. Globally plants have been reported to contain compounds with insecticidal properties. These properties have been demonstrated more recently on the larval stages of mosquitoes. Therefore, Citrus cultivar seeds were evaluated for larvicidal potential against the primary dengue vector Aedes aegypti . Extraction of oil was done by a steam distillation method and oils were evaluated according to WHO guidelines for larvicides 2005 for evaluation of insecticidal properties of citrus seed extracts against mosquito larvae. Among the Citrus cultivar seed oil, rough lemon ( Citrus jambhiri ) had the lowest LC 50 value (200.79ppm), while musambi ( C. sinensis var musambi ) had the highest LC 50 value (457.30ppm) after 24 h of exposure. Citrus cultivars have some larvicidal potential but C. jambhiri had the greatest potential against A. aegypti larvae. Further small-scale field trials using the extracts of C. jambhiri will be conducted to determine operational feasibility.

  14. Sodium Channel Mutations and Pyrethroid Resistance in Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Yuzhe Du

    2016-10-01

    Full Text Available Pyrethroid insecticides are widely used to control insect pests and human disease vectors. Voltage-gated sodium channels are the primary targets of pyrethroid insecticides. Mutations in the sodium channel have been shown to be responsible for pyrethroid resistance, known as knockdown resistance (kdr, in various insects including mosquitoes. In Aedes aegypti mosquitoes, the principal urban vectors of dengue, zika, and yellow fever viruses, multiple single nucleotide polymorphisms in the sodium channel gene have been found in pyrethroid-resistant populations and some of them have been functionally confirmed to be responsible for kdr in an in vitro expression system, Xenopus oocytes. This mini-review aims to provide an update on the identification and functional characterization of pyrethroid resistance-associated sodium channel mutations from Aedes aegypti. The collection of kdr mutations not only helped us develop molecular markers for resistance monitoring, but also provided valuable information for computational molecular modeling of pyrethroid receptor sites on the sodium channel.

  15. Evaluation of collection methods for Culex quinquefasciatus, Aedes aegypti, and Aedes simpsoni in northeastern Tanzania.

    Science.gov (United States)

    Thornton, Jonathan Harold; Batengana, Bernard Malongo; Eiras, Alvaro Eduardo; Irish, Seth Robert

    2016-12-01

    In East Africa, significant morbidity and mortality are caused by infections spread by Culex quinquefasciatus and Aedes aegypti. Sticky traps have been shown to be effective tools for sampling populations of Aedes mosquitoes and have been found to catch Cx. quinquefasciatus. Thus, they could potentially be used to sample populations of this species. This study compared Sticky ovitraps (SO) and MosquiTraps (MQT) with the CDC Gravid trap (CDC-GT) for collection of Culex and Aedes mosquito populations in Tanzania. A follow-up experiment was carried out using traps set for a 24-h period to accommodate the oviposition habits of Aedes aegypti and Ae. simpsoni s.l. mosquitoes. The results showed that the CDC-GT caught significantly more Cx. quinquefasciatus and Ae. aegypti than the SO or MQT, but there was no significant difference in the number of mosquitoes caught between the two sticky traps or of Ae. simpsoni s.l. caught among the three trap types. The results suggest that CDC-GTs are the most appropriate in sampling of Cx. quinquefasciatus. Although CDC-GTs collected more Ae. aegypti than the sticky traps, the simplicity and cost benefit of sticky traps facilitates large scale studies. All three trap types should be considered for monitoring Aedes mosquitoes. © 2016 The Society for Vector Ecology.

  16. Experimental transmission of Mayaro virus by Aedes aegypti.

    Science.gov (United States)

    Long, Kanya C; Ziegler, Sarah A; Thangamani, Saravanan; Hausser, Nicole L; Kochel, Tadeusz J; Higgs, Stephen; Tesh, Robert B

    2011-10-01

    Outbreaks of Mayaro fever have been associated with a sylvatic cycle of Mayaro virus (MAYV) transmission in South America. To evaluate the potential for a common urban mosquito to transmit MAYV, laboratory vector competence studies were performed with Aedes aegypti from Iquitos, Peru. Oral infection in Ae. aegypti ranged from 0% (0/31) to 84% (31/37), with blood meal virus titers between 3.4 log(10) and 7.3 log(10) plaque-forming units (PFU)/mL. Transmission of MAYV by 70% (21/30) of infected mosquitoes was shown by saliva collection and exposure to suckling mice. Amount of viral RNA in febrile humans, determined by real-time polymerase chain reaction, ranged from 2.7 to 5.3 log(10) PFU equivalents/mL. Oral susceptibility of Ae. aegypti to MAYV at titers encountered in viremic humans may limit opportunities to initiate an urban cycle; however, transmission of MAYV by Ae. aegypti shows the vector competence of this species and suggests potential for urban transmission.

  17. Low density lipopolyprotein inhibits flavivirus acquisition in Aedes aegypti.

    Science.gov (United States)

    Wagar, Z L; Tree, M O; Mpoy, M C; Conway, M J

    2017-12-01

    Aedes aegypti is the primary vector of a number of human pathogens including dengue virus (DENV) and Zika virus (ZIKV). Ae. aegypti acquires these viruses during the processing of bloodmeals obtained from an infected vertebrate host. Vertebrate blood contains a number of factors that have the potential to modify virus acquisition in the mosquito. Interestingly, low density lipopolyprotein (LDL) levels are decreased during severe DENV infection. Accordingly, we hypothesized that LDL is a modifiable factor that can influence flavivirus acquisition in the mosquito. We found that LDL is endocytosed by Ae. aegypti cells in a dynamin-dependent manner. LDL is also endocytosed by midgut epithelial cells and accumulates at the luminal midgut epithelium during bloodmeal digestion. Importantly, pretreatment with LDL, but not high density lipopolyprotein (HDL), significantly inhibited both DENV and ZIKV infection in vitro, and LDL inhibited ZIKV infection in vivo. This study identifies human LDL or 'bad cholesterol' as a modifiable factor that can inhibit flavivirus acquisition in Ae. aegypti. Identification of modifiable blood factors and critical cellular interactions that mediate pathogen acquisition may lead to novel strategies to disrupt the transmission cycle of vector-borne diseases. © 2017 The Royal Entomological Society.

  18. Field performance of engineered male mosquitoes.

    Science.gov (United States)

    Harris, Angela F; Nimmo, Derric; McKemey, Andrew R; Kelly, Nick; Scaife, Sarah; Donnelly, Christl A; Beech, Camilla; Petrie, William D; Alphey, Luke

    2011-10-30

    Dengue is the most medically important arthropod-borne viral disease, with 50-100 million cases reported annually worldwide. As no licensed vaccine or dedicated therapy exists for dengue, the most promising strategies to control the disease involve targeting the predominant mosquito vector, Aedes aegypti. However, the current methods to do this are inadequate. Various approaches involving genetically engineered mosquitoes have been proposed, including the release of transgenic sterile males. However, the ability of laboratory-reared, engineered male mosquitoes to effectively compete with wild males in terms of finding and mating with wild females, which is critical to the success of these strategies, has remained untested. We report data from the first open-field trial involving a strain of engineered mosquito. We demonstrated that genetically modified male mosquitoes, released across 10 hectares for a 4-week period, mated successfully with wild females and fertilized their eggs. These findings suggest the feasibility of this technology to control dengue by suppressing field populations of A. aegypti.

  19. Fate of blood meal iron in mosquitos

    OpenAIRE

    Zhou, Guoli; Kohlhepp, Pete; Geiser, Dawn; Frasquillo, Maria del Carmen; Vazquez-Moreno, Luz; Winzerling, Joy J.

    2007-01-01

    Iron is an essential element of living cells and organisms as a component of numerous metabolic pathways. Hemoglobin and ferric-transferrin in vertebrate host blood are the two major iron sources for female mosquitoes. We used inductively coupled plasma mass spectrometry (ICP-MS) and radioisotope-labeling to quantify the fate of iron supplied from hemoglobin or as transferrin in Aedes aegypti. At the end of the first gonotrophic cycloe, ~87% of the ingested total meal heme iron was excreted, ...

  20. Comparative assessment of the bacterial communities associated with Aedes aegypti larvae and water from domestic water storage containers.

    Science.gov (United States)

    Dada, Nsa; Jumas-Bilak, Estelle; Manguin, Sylvie; Seidu, Razak; Stenström, Thor-Axel; Overgaard, Hans J

    2014-08-24

    Domestic water storage containers constitute major Aedes aegypti breeding sites. We present for the first time a comparative analysis of the bacterial communities associated with Ae. aegypti larvae and water from domestic water containers. The 16S rRNA-temporal temperature gradient gel electrophoresis (TTGE) was used to identify and compare bacterial communities in fourth-instar Ae. aegypti larvae and water from larvae positive and negative domestic containers in a rural village in northeastern Thailand. Water samples were cultured for enteric bacteria in addition to TTGE. Sequences obtained from TTGE and bacterial cultures were clustered into operational taxonomic units (OTUs) for analyses. Significantly lower OTU abundance was found in fourth-instar Ae. aegypti larvae compared to mosquito positive water samples. There was no significant difference in OTU abundance between larvae and mosquito negative water samples or between mosquito positive and negative water samples. Larval samples had significantly different OTU diversity compared to mosquito positive and negative water samples, with no significant difference between mosquito positive and negative water samples. The TTGE identified 24 bacterial taxa, belonging to the phyla Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and TM7 (candidate phylum). Seven of these taxa were identified in larval samples, 16 in mosquito positive and 13 in mosquito negative water samples. Only two taxa, belonging to the phyla Firmicutes and Actinobacteria, were common to both larvae and water samples. Bacilli was the most abundant bacterial class identified from Ae. aegypti larvae, Gammaproteobacteria from mosquito positive water samples, and Flavobacteria from mosquito negative water samples. Enteric bacteria belonging to the class Gammaproteobacteria were sparsely represented in TTGE, but were isolated from both mosquito positive and negative water samples by selective culture. Few bacteria from water samples were

  1. EFFECT OF STORAGE TEMPERATURE PERCENTAGE OF EGG HATCHING OF AEDES AEGYPTI IN LABORATORY=PENGARUH SUHU PENYIMPANAN TERHADAP PRESENTASE TETAS TELUR Aedes aegypti DI LABORATORIUM

    Directory of Open Access Journals (Sweden)

    Riyani Setiyaningsih

    2015-03-01

    Full Text Available EnglishABSTRACTAedes aegypti is the vector of Dengue Hemorrhagic Fever (DHF in Indonesia. Ae. aegypti has a high reproductive capacity, one female mosquitoes can lay 100-150 eggs. Eggs of Ae. aegypti can survive on dry temperatures within a few months, thus increasing the chances of transmission of dengue virus The aim of the study was to determine the effect of temperature on egg hatching percentage of Ae. aegypti. Eggs Ae. aegypti colonization in laboratory results are stored at room temperature and refrigerator temperature. Observations percentage of eggs hatching was observed at month zero, one, two, third, fourth, fifth, and sixth. The results of the study until the sixth month percentage of hatching eggs at room temperature was 63,17, 59,26, 24,33, 13,62, 10, and 0%. While storage on egg hatching refrigerator not occur in the first to sixth.INDONESIANAedes aegypti merupakan vektor Demam Berdarah Dengue (DBD di Indonesia. Ae. aegypti memiliki kemampuan reproduksi yang tinggi, satu ekor nyamuk betina dapat bertelur 100-150 butir telur. Telur Ae. aegypti mampu bertahan hidup pada suhu kering dalam beberapa bulan sehingga memperbesar peluang terjadinnya proses penularan virus DBD. Tujuan penelitian adalah mengetahui pengaruh suhu dan lama penyimpanan terhadap presentase penetasan telur Ae. aegypti. Telur Ae. aegypti hasil kolonisasi di laboratorium disimpan pada suhu ruang dan suhu refrigerator. Pengamatan presentase penetasan telur diamati pada bulan ke nol, kesatu, kedua, ketiga, keempat, kelima, dan keenam. Hasil penelitian pada bulan bertama sampai keenam presentase penetasan telur pada suhu ruang adalah 63,17, 59,26, 24,33, 13,62, 10, dan 0%. Sedangkan penyimpanan pada suhu kukas tidak terjadi penetasan telur pada bulan pertama sampai keenam.

  2. Community-Based Control of Aedes aegypti By Using Mesocyclops in Southern Vietnam

    Science.gov (United States)

    Nam, Vu Sinh; Yen, Nguyen Thi; Duc, Hoang Minh; Tu, Tran Cong; Thang, Vu Trong; Le, Nguyen Hoang; San, Le Hoang; Loan, Luu Le; Huong, Vu Thi Que; Khanh, Ly Huynh Kim; Trang, Huynh Thi Thuy; Lam, Leonie Z. Y.; Kutcher, Simon C.; Aaskov, John G.; Jeffery, Jason A. L.; Ryan, Peter A.; Kay, Brian H.

    2012-01-01

    We previously reported a new community-based mosquito control strategy that resulted in elimination of Aedes aegypti (Linn.) in 40 of 46 communes in northern and central Vietnam, and with annual recurrent total costs (direct and indirect) of only $0.28–$0.89 international dollars per person. This control strategy was extended to four provinces in southern Vietnam in Long An and Hau Giang (2004–2007) and to Long An, Ben Tre, and Vinh Long (2005–2010). In a total of 14 communes with 124,743 residents, the mean ± SD of adult female Ae. aegypti was reduced from 0.93 ± 0.62 to 0.06 ± 0.09, and the reduction of immature Ae. aegypti averaged 98.8%. By the final survey, no adults could be collected in 6 of 14 communes, and one commune, Binh Thanh, also had no immature forms. Although the community-based programs also involved community education and clean-up campaigns, the prevalence of Mesocyclops in large water storage containers > 50 liters increased from 12.77 ± 8.39 to 75.69 ± 9.17% over periods of 15–45 months. At the conclusion of the study, no confirmed dengue cases were detected in four of the five communes for which diagnostic serologic analysis was performed. The rate of progress was faster in communes that were added in stages to the program but the reason for this finding was unclear. At the completion of the formal project, sustainability funds were set up to provide each commune with the financial means to ensure that community-based dengue control activities continued. PMID:22556087

  3. The Genetics of Chemoreception in the Labella and Tarsi of Aedes aegypti

    Science.gov (United States)

    2014-01-01

    Published by Elsevier Ltd. 1. Introduction Aedes aegypti (L.) ( Diptera : Culicidae) mosquitoes contribute to the spread of dengue, yellow fever...specific molecular components potentially involved in chemical attraction and avoidance. Expressed putative chemore- ception genes in male and female...et al., 2005; Abuin et al., 2011). Pro- pionic acid and other carboxylic acids are mosquito attractants in the context of odor blends containing

  4. Insecticide susceptibility status of human biting mosquitoes in ...

    African Journals Online (AJOL)

    Matowo Pc

    temperature and humidity, respectively. Dead and surviving mosquitoes at the end of an experiment were kept in separate Eppendorf tubes ..... levels or differential efficacy of metabolic genes (Lima et al., 2011). Additionally, Ae. aegypti formosus exhibited possible resistance to DDT. The findings of the present study are ...

  5. Susceptibility of some species of mosquitoes to permethrin ...

    African Journals Online (AJOL)

    The susceptibility of Aedes aegypti Linnaeus 1762, Culex quinquefasciatus Say 1823 and Anopheles gambiae Giles 1902 was tested on 0.75 % permethrin pyrethroid in the laboratory. All Larval and pupal stages of the mosquitoes were collected from different localities within Zaria, Nigeria and reared to adulthood in the ...

  6. Potential of some Nigerian plants as mosquito larvicides | Agboola ...

    African Journals Online (AJOL)

    Crude ethanolic extracts of thirteen plants from Nigeria were screened for larvicidal activity against fourth instar Aedes aegypti mosquito. Only seven of these were active (LC50 ≤ 6.25ppm). Activity of the solvent partitioned-extracts derived from the more active plants was in the order: EtOAc < BuOH 2O (for Pseudocedrela ...

  7. Larvicidal effects of lemon peels on mosquito larvae | ANYANWU ...

    African Journals Online (AJOL)

    Methanol extract of the dry peels of the common edible plant, Citrus limon (family, Rutaceae), was obtained using a Soxhlet extractor and its larviciding effect evaluated against the larvae of two household mosquitoes: Aedes aegypti and Culex quinquefasciatus. Each batch of larvae (20-30) were treated with 3.90, 15.63, ...

  8. Acoustic control of mosquito larvae in artificial drinking water containers

    Science.gov (United States)

    Acoustic larvicide devices are part of an emerging technology that provides a non-chemical and non-biological means to reduce larval populations of key medically important mosquito species such as Aedes aegypti in containers or catchments of water. These devices could benefit integrated vector manag...

  9. Mitigating Diseases Transmitted by Aedes Mosquitoes: A Cluster-Randomised Trial of Permethrin-Impregnated School Uniforms.

    Science.gov (United States)

    Kittayapong, Pattamaporn; Olanratmanee, Phanthip; Maskhao, Pongsri; Byass, Peter; Logan, James; Tozan, Yesim; Louis, Valérie; Gubler, Duane J; Wilder-Smith, Annelies

    2017-01-01

    Viral diseases transmitted via Aedes mosquitoes are on the rise, such as Zika, dengue, and chikungunya. Novel tools to mitigate Aedes mosquitoes-transmitted diseases are urgently needed. We tested whether commercially insecticide-impregnated school uniforms can reduce dengue incidence in school children. We designed a cluster-randomised controlled trial in Thailand. The primary endpoint was laboratory-confirmed dengue infections. Secondary endpoints were school absenteeism; and impregnated uniforms' 1-hour knock-down and 24 hour mosquito mortality as measured by standardised WHOPES bioassay cone tests at baseline and after repeated washing. Furthermore, entomological assessments inside classrooms and in outside areas of schools were conducted. We enrolled 1,811 pupils aged 6-17 from 5 intervention and 5 control schools. Paired serum samples were obtained from 1,655 pupils. In the control schools, 24/641 (3.7%) and in the intervention schools 33/1,014 (3.3%) students had evidence of new dengue infections during one school term (5 months). There was no significant difference in proportions of students having incident dengue infections between the intervention and control schools, with adjustment for clustering by school. WHOPES cone tests showed a 100% knock down and mortality of Aedes aegypti mosquitoes exposed to impregnated clothing at baseline and up to 4 washes, but this efficacy rapidly declined to below 20% after 20 washes, corresponding to a weekly reduction in knock-down and mosquito mortality by 4.7% and 4.4% respectively. Results of the entomological assessments showed that the mean number of Aedes aegypti mosquitoes caught inside the classrooms of the intervention schools was significantly reduced in the month following the introduction of the impregnated uniforms, compared to those collected in classrooms of the control schools (p = 0.04). Entomological assessments showed that the intervention had some impact on the number of Aedes mosquitoes inside

  10. Mitigating Diseases Transmitted by Aedes Mosquitoes: A Cluster-Randomised Trial of Permethrin-Impregnated School Uniforms.

    Directory of Open Access Journals (Sweden)

    Pattamaporn Kittayapong

    2017-01-01

    Full Text Available Viral diseases transmitted via Aedes mosquitoes are on the rise, such as Zika, dengue, and chikungunya. Novel tools to mitigate Aedes mosquitoes-transmitted diseases are urgently needed. We tested whether commercially insecticide-impregnated school uniforms can reduce dengue incidence in school children.We designed a cluster-randomised controlled trial in Thailand. The primary endpoint was laboratory-confirmed dengue infections. Secondary endpoints were school absenteeism; and impregnated uniforms' 1-hour knock-down and 24 hour mosquito mortality as measured by standardised WHOPES bioassay cone tests at baseline and after repeated washing. Furthermore, entomological assessments inside classrooms and in outside areas of schools were conducted.We enrolled 1,811 pupils aged 6-17 from 5 intervention and 5 control schools. Paired serum samples were obtained from 1,655 pupils. In the control schools, 24/641 (3.7% and in the intervention schools 33/1,014 (3.3% students had evidence of new dengue infections during one school term (5 months. There was no significant difference in proportions of students having incident dengue infections between the intervention and control schools, with adjustment for clustering by school. WHOPES cone tests showed a 100% knock down and mortality of Aedes aegypti mosquitoes exposed to impregnated clothing at baseline and up to 4 washes, but this efficacy rapidly declined to below 20% after 20 washes, corresponding to a weekly reduction in knock-down and mosquito mortality by 4.7% and 4.4% respectively. Results of the entomological assessments showed that the mean number of Aedes aegypti mosquitoes caught inside the classrooms of the intervention schools was significantly reduced in the month following the introduction of the impregnated uniforms, compared to those collected in classrooms of the control schools (p = 0.04.Entomological assessments showed that the intervention had some impact on the number of Aedes

  11. Mukia maderaspatana (Cucurbitaceae) extract-mediated synthesis of silver nanoparticles to control Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Chitra, Govindaraj; Balasubramani, Govindasamy; Ramkumar, Rajendiran; Sowmiya, Rajamani; Perumal, Pachiappan

    2015-04-01

    Mosquitoes and mosquito-borne diseases are prone to raise health and economic impacts. Synthetic insecticide-based interventions are indeed in situations of epidemic outbreak and sudden increases of adult mosquitoes. Nanoparticles are being used in many commercial applications and were found that aqueous silver ions can be reduced by an aqueous extract of plant parts to generate extremely stable silver nanoparticles in water. Based on this, silver nanoparticles (SNPs) were synthesized using leaf aqueous extract (LAE) of Mukia maderaspatana. Further, the synthesized SNPs were characterized by UV-visible spectrum, which indicated a strong plasmon resonance at 427 nm. X-ray diffraction (XRD) analysis revealed the average crystalline size of the synthesized SNPs was approximately 64 nm by Debye-Scherrer formulae. Fourier transform infrared (FTIR) spectroscopy analysis revealed the presence of different functional groups like amines, halides, alkanes, alkynes, amides, and esters with respective stretches, which are responsible for the bio-reduction of silver ions. Field emission scanning electron microscopy (FESEM) depicted the spherical morphology of SNPs with size range of 13-34 nm. The larvicidal activity of LAE and SNPs exhibited an effective mortality to Aedes aegypti and Culex quinquefasciatus. The lethal concentration (LC50; LC90) of LAE and SNPs were found to be 0.506; 1.082, 0.392; 0.870 ppm and 0.211; 0.703, 0.094; 0.482 ppm, respectively on A. aegypti and C. quinquefasciatus. Thus, the synthesized SNPs have shown preponderant larvicidal activity, but further studies are needed to formulate the potential larvicidal agents.

  12. The influence of dengue virus serotype-2 infection on Aedes aegypti (Diptera: Culicidae motivation and avidity to blood feed.

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    Rafael Maciel-de-Freitas

    Full Text Available BACKGROUND: Dengue virus (DENV is transmitted by Aedes aegypti, a species that lives in close association with human dwellings. The behavior of DENV-infected mosquitoes needs further investigation, especially regarding the potential influence of DENV on mosquito biting motivation and avidity. METHODOLOGY/PRINCIPAL FINDINGS: We orally challenged 4-5 day-old Ae. aegypti females with a low passage DENV serotype -2 (DENV-2 to test whether the virus influences motivation to feed (the likelihood that a mosquito obtains a blood-meal and the size of its blood meal and avidity (the likelihood to re-feed after an interrupted first blood-meal. To assay motivation, we offered mosquitoes an anesthetized mouse for 2, 3, 4 or 5 minutes 7 or 14 days after the initial blood meals and measured the time they started feeding. 60.5% of the unexposed mosquitoes fed on the mouse, but only 40.5% of the positive ones did. Exposed but negative mosquitoes behaved similarly to unexposed ones (55.0% feeding. Thus DENV-2 infection decreased the mosquitoes' motivation to feed. To assay avidity, we offered the same mosquitoes a mouse two hours after the first round of feeding, and we measured the time at which they started probing. The exposed (positive or negative mosquitoes were more likely to re-feed than the unexposed ones and, in particular, the size of the previous blood-meal that kept mosquitoes from re-feeding was larger in the exposed than in the unexposed mosquitoes. Thus, DENV-2 infection increased mosquito avidity. CONCLUSIONS/SIGNIFICANCE: DENV-2 significantly decreased the mosquitoes' motivation to feed, but increased their avidity (even after taking account the amount of blood previously imbibed. As these are important components of transmission, we expect that the changes of the blood-feeding behaviour impact the vectorial capacity Ae. aegypti for dengue.

  13. The influence of dengue virus serotype-2 infection on Aedes aegypti (Diptera: Culicidae) motivation and avidity to blood feed.

    Science.gov (United States)

    Maciel-de-Freitas, Rafael; Sylvestre, Gabriel; Gandini, Mariana; Koella, Jacob C

    2013-01-01

    Dengue virus (DENV) is transmitted by Aedes aegypti, a species that lives in close association with human dwellings. The behavior of DENV-infected mosquitoes needs further investigation, especially regarding the potential influence of DENV on mosquito biting motivation and avidity. We orally challenged 4-5 day-old Ae. aegypti females with a low passage DENV serotype -2 (DENV-2) to test whether the virus influences motivation to feed (the likelihood that a mosquito obtains a blood-meal and the size of its blood meal) and avidity (the likelihood to re-feed after an interrupted first blood-meal). To assay motivation, we offered mosquitoes an anesthetized mouse for 2, 3, 4 or 5 minutes 7 or 14 days after the initial blood meals and measured the time they started feeding. 60.5% of the unexposed mosquitoes fed on the mouse, but only 40.5% of the positive ones did. Exposed but negative mosquitoes behaved similarly to unexposed ones (55.0% feeding). Thus DENV-2 infection decreased the mosquitoes' motivation to feed. To assay avidity, we offered the same mosquitoes a mouse two hours after the first round of feeding, and we measured the time at which they started probing. The exposed (positive or negative) mosquitoes were more likely to re-feed than the unexposed ones and, in particular, the size of the previous blood-meal that kept mosquitoes from re-feeding was larger in the exposed than in the unexposed mosquitoes. Thus, DENV-2 infection increased mosquito avidity. DENV-2 significantly decreased the mosquitoes' motivation to feed, but increased their avidity (even after taking account the amount of blood previously imbibed). As these are important components of transmission, we expect that the changes of the blood-feeding behaviour impact the vectorial capacity Ae. aegypti for dengue.

  14. The endosymbiotic bacterium Wolbachia induces resistance to dengue virus in Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Guowu Bian

    2010-04-01

    Full Text Available Genetic strategies that reduce or block pathogen transmission by mosquitoes have been proposed as a means of augmenting current control measures to reduce the growing burden of vector-borne diseases. The endosymbiotic bacterium Wolbachia has long been promoted as a potential vehicle for introducing disease-resistance genes into mosquitoes, thereby making them refractory to the human pathogens they transmit. Given the large overlap in tissue distribution and intracellular localization between Wolbachia and dengue virus in mosquitoes, we conducted experiments to characterize their interactions. Our results show that Wolbachia inhibits viral replication and dissemination in the main dengue vector, Aedes aegypti. Moreover, the virus transmission potential of Wolbachia-infected Ae. aegypti was significantly diminished when compared to wild-type mosquitoes that did not harbor Wolbachia. At 14 days post-infection, Wolbachia completely blocked dengue transmission in at least 37.5% of Ae. aegypti mosquitoes. We also observed that this Wolbachia-mediated viral interference was associated with an elevated basal immunity and increased longevity in the mosquitoes. These results underscore the potential usefulness of Wolbachia-based control strategies for population replacement.

  15. Environmental factors affecting efficacy of bifenthrin-treated vegetation for mosquito control.

    Science.gov (United States)

    Allan, Sandra A; Kline, Daniel L; Walker, Todd

    2009-09-01

    The use of pesticide-treated vegetation as a barrier for control of nuisance and disease-bearing mosquitoes has become an option for mosquito management for home owners and public health and mosquito control professionals. Potted wax myrtle and azalea plants were treated with bifenthrin (0.79% AI) at maximum label rate using backpack and electrostatic sprayers and exposed to various treatments that could affect the residual degradation of the applied pesticides. Treatments included leaf aspect, simulated rainfall, shade, and natural sun exposure with the residual effectiveness of leaves examined in tarsal contact Petri dish assays using laboratory-reared Aedes aegypti. There was no significant difference in efficacy between the adaxial (top) or abaxial (bottom) surfaces of electrostatically or backpack-treated leaves. Significant differences existed between application method, plant species, and exposure with most significant effects between weeks 1 and 4. Simulated heavy rainfalls applied 3 times weekly reduced knockdown by leaves treated with electrostatic and backpack methods with reductions seen as soon as 1 wk after treatment. Reductions were seen with both wax myrtle and azalea leaves and after 1, 4, and 24 h contact of mosquitoes to leaves. Placement of plants with full exposure to sunlight also significantly reduced efficacy compared to plants placed in the shade. Differences were observed most often for 4 and 24 h knockdown counts, and significant decreases were seen from week 4 onwards. Clearly factors such as rain and exposure to sun impact degradation of efficacy of bifenthrin-treated vegetation in the field. Degradation of bifenthrin efficacy was slowest in sites protected from rain and sun, which coincide with preferred resting site locations for many mosquito species.

  16. Septic tank mosquitoes: competition between species in central Nigeria.

    Science.gov (United States)

    Irving-Bell, R J; Okoli, E I; Diyelong, D Y; Lyimo, E O; Onyia, O C

    1987-07-01

    Exit traps, placed over the air vents of septic tanks, were used to examine species diversity and relative abundance of mosquitoes breeding in ammonia-rich waters of septic tanks. Of the six species found, Culex decens Theobald and Culex cinereus Theobald appeared to be competing successfully with Culex quinquefasciatus Say during the wet season but not during the long dry season. The seasonal timing of their displacement by Cx quinquefasciatus was variable and did not correlate well with climatic factors. The three other species present, generally during the wet season and early dry season, were Culex tigripes G. & C., Culex horridus Edwards and Aedes aegypt (L.). Experimental bucket ovitraps were used to assess preference towards covered (dark) septic tank water in comparison with sunlit septic tank water, covered and sunlit compost water. These were colonized by Cx quinquefasciatus, Cx decens, Ae. aegypti and Ae. vittatus Bigot. The covered septic tank water was more abundantly colonized by Cx quinquefasciatus and marginally so by the two Aedes species. Cx decens appeared to colonize the exposed compost water more readily in the dry season, but changed to the covered septic tank water in the wet season. The discussion centres around competition between these mosquitos species and concludes that it would be useful to know what environmental factors, or what aspects of competition, lead to severe natural reductions in the abundance of the major pest species Cx quinquefasciatus.

  17. Species Distribution Modelling of Aedes aegypti in two dengue-endemic regions of Pakistan.

    Science.gov (United States)

    Fatima, Syeda Hira; Atif, Salman; Rasheed, Syed Basit; Zaidi, Farrah; Hussain, Ejaz

    2016-03-01

    Statistical tools are effectively used to determine the distribution of mosquitoes and to make ecological inferences about the vector-borne disease dynamics. In this study, we utilised species distribution models to understand spatial patterns of Aedes aegypti in two dengue-prevalent regions of Pakistan, Lahore and Swat. Species distribution models can potentially indicate the probability of suitability of Ae. aegypti once introduced to new regions like Swat, where invasion of this species is a recent phenomenon. The distribution of Ae. aegypti was determined by applying the MaxEnt algorithm on a set of potential environmental factors and species sample records. The ecological dependency of species on each environmental variable was analysed using response curves. We quantified the statistical performance of the models based on accuracy assessment and spatial predictions. Our results suggest that Ae. aegypti is widely distributed in Lahore. Human population density and urban infrastructure are primarily responsible for greater probability of mosquito occurrence in this region. In Swat, Ae. aegypti has clumped distribution, where urban patches provide refuge to the species in an otherwise hostile heterogeneous environment and road networks are assumed to have facilitated in passive-mediated dispersal of species. In Pakistan, Ae. aegypti is expanding its range northwards; this could be associated with rapid urbanisation, trade and travel. The main implication of this expansion is that more people are at risk of dengue fever in the northern highlands of Pakistan. © 2016 John Wiley & Sons Ltd.

  18. Culex Species Mosquitoes and Zika Virus.

    Science.gov (United States)

    Huang, Yan-Jang S; Ayers, Victoria B; Lyons, Amy C; Unlu, Isik; Alto, Barry W; Cohnstaedt, Lee W; Higgs, Stephen; Vanlandingham, Dana L

    2016-10-01

    Recent reports of Zika virus (ZIKV) isolates from Culex species mosquitoes have resulted in concern regarding a lack of knowledge on the number of competent vector species for ZIKV transmission in the new world. Although observations in the field have demonstrated that ZIKV isolation can be made from Culex species mosquitoes, the detection of ZIKV in these mosquitoes is not proof of their involvement in a ZIKV transmission cycle. Detection may be due to recent feeding on a viremic vertebrate, and is not indicative of replication in the mosquito. In this study, susceptibility of recently colonized Culex species mosquitoes was investigated. The results showed a high degree of refractoriness among members of Culex pipiens complex to ZIKV even when exposed to high-titer bloodmeals. Our finding suggests that the likelihood of Culex species mosquitoes serving as secondary vectors for ZIKV is very low, therefore vector control strategies for ZIKV should remain focused on Aedes species mosquitoes. Our demonstration that Culex quinquefasciatus from Vero Beach, FL, is refractory to infection with ZIKV is especially important and timely. Based on our data, we would conclude that the autochthonous cases of Zika in Florida are not due to transmission by C. quinquefasciatus, and so control efforts should focus on other species, logically Aedes aegypti and Aedes albopictus.

  19. Wolbachia-a foe for mosquitoes

    Directory of Open Access Journals (Sweden)

    Nadipinayakanahalli Munikrishnappa Guruprasad

    2014-02-01

    Full Text Available Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmful vectors. Recently, a novel approach to control mosquitoes by transinfection of life shortening maternally transmitted endo-symbiont Wolbachia wMelPop strain from fruitfly Drosophila into mosquito population has been developed by researchers. The wMelPop strain up-regulated the immune gene expression in mosquitoes thereby reducing the dengue and Chickungunya viral replication in Aedes aegypti, and also it significantly reduced the Plasmodium level in Anopheles gambiae. Here, we discuss the strategy of using Wolbachia in control of vector-borne diseases of mosquitoes.

  20. Tackling the growing threat of dengue: Phyllanthus niruri-mediated synthesis of silver nanoparticles and their mosquitocidal properties against the dengue vector Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    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...

  1. GLOBE Goes GO with Mosquitoes

    Science.gov (United States)

    Boger, R. A.; Low, R.

    2016-12-01

    The GLOBE Mosquito Larvae protocol and a new citizen science initiative, GLOBE Observers (GO), were both launched in Summer 2016. While the GLOBE Mosquito Larvae Protocol and associated educational materials target K-16 student inquiry and research, the GO protocol version is simplified to enable citizen scientists of all ages from all walks of life to participate. GO allows citizen scientists to collect and submit environmental data through an easy-to-use smart phone app available for both Apple and Android mobile devices. GO mosquito asks for photos of larvae mosquito genus or species, location, and type of water source (e.g., container or pond) where the larvae were found. To initiate the new mosquito GLOBE/GO opportunities, workshops have been held in Barbuda, Thailand, West Indies, US Gulf Coast, New York City, and at the GLOBE Annual Meeting in Colorado. Through these venues, the protocols have been refined and a field campaign has been initiated so that GO and GLOBE citizen scientists (K-16 students and all others) can contribute data. Quality assurance measures are taken through the online training required to participate and the validation of identification by other citizen sciences and mosquito experts. Furthermore, initial research is underway to develop optical recognition software starting with the species that carry the Zika virus (Aedes aegypti and A. albopictus). With this launch, we plan to move forward by providing opportunities throughout the world to engage people in meaningful environmental and public health data collection and to promote citizen scientists to become agents of change in their communities.

  2. Comparison of BG-Sentinel Trap and Oviposition Cups for Aedes aegypti and Aedes albopictus Surveillance in Jacksonville, Florida, USA

    Science.gov (United States)

    2015-03-01

    its role in yellow fever virus transmission (Schliessmann and Magennis 1964, O’Meara et al. 1993). The introduction of Ae. albopictus into the USA...Phylogeography of Aedes aegypti ( yellow fever mosquito) in south Florida: mtDNA evidence for human-aided dispersal. Am J Trop Med Hyg 29:482– 488. Darsie RF...COMPARISON OF BG-SENTINELH TRAP AND OVIPOSITION CUPS FOR AEDES AEGYPTI AND AEDES ALBOPICTUS SURVEILLANCE IN JACKSONVILLE, FLORIDA, USA JENNIFER A

  3. Evaluation of Three Commercial Backpack Sprayers with Aqualuer (registered trademark) 20-20 Against Caged Adult Aedes aegypti

    Science.gov (United States)

    2016-03-11

    1993. The yellow fever mosquito, Aedes aegypti. Wing Beats 5(4):4. Xue RD, Qualls WA, Smith ML, Zhao TY, Brown JR. 2012. Evaluation of Pioneer Eco...Anopheles quadrimaculatus, Aedes aegypti and Aedes albopictus . J Am Mosq Control Assoc 27:330–332. Gerberg EJ, Barnard DR, Ward RA. 1994. Manual for...Backpack sprayer and Twister XL Backpack Sprayer using Aqualuer against caged adult Aedes albopictus and Culex quinquefasciatus. J Am Mosq Control Assoc

  4. Knockdown resistance (kdr) of the voltage-gated sodium channel gene of Aedes aegypti population in Denpasar, Bali, Indonesia.

    Science.gov (United States)

    Hamid, Penny Humaidah; Prastowo, Joko; Widyasari, Anis; Taubert, Anja; Hermosilla, Carlos

    2017-06-05

    Aedes aegypti is the main vector of several arthropod-borne viral infections in the tropics profoundly affecting humans, such as dengue fever (DF), West Nile (WN), chikungunya and more recently Zika. Eradication of Aedes still largely depends on insecticides, which is the most cost-effective strategy, and often inefficient due to resistance development in exposed Aedes populations. We here conducted a study of Ae. aegypti resistance towards several insecticides regularly used in the city of Denpasar, Bali, Indonesia. Aedes aegypti egg samples were collected with ovitraps and thereafter hatched in the insectary of the Gadjah Mada University. The F0 generation was used for all bioassay-related experiments and knockdown resistance (kdr) assays. Results clearly showed resistance development of Ae. aegypti against tested insecticides. Mortalities of Ae. aegypti were less than 90% with highest resistance observed against 0.75% permethrin. Mosquitoes from the southern parts of Denpasar presented high level of resistance pattern in comparison to those from the western and northern parts of Denpasar. Kdr analysis of voltage-gated sodium channel (Vgsc) gene showed significant association to S989P and V1016G mutations linked to resistance phenotypes against 0.75% permethrin. Conversely, Ae. aegypti F1534C gene mutation did not result in any significant correlation to resistance development. Periodically surveillance of insecticide resistances in Ae. aegypti mosquitoes will help local public health authorities to set better goals and allow proper evaluation of on-going mosquito control strategies. Initial detection of insecticide resistance will contribute to conduct proper actions in delaying mosquito resistance development such as insecticide rotation or combination of compounds in order to prolong chemical efficacy in combating Ae. aegypti vectors in Indonesia.

  5. Transgenic expression of the Aedes aegypti CYP9J28 confers pyrethroid resistance in Drosophila melanogaster

    NARCIS (Netherlands)

    Pavlidi, N.; Monastirioti, M.; Daborn, P.; Van Leeuwen, T.; Vontas, J.

    2012-01-01

    The emergence and spread of insecticide resistance in mosquitoes, such as the major vector of dengue and yellow fever Aedes aegypti, is a major public health problem. A number of studies have been conducted to-date aiming to identify specific molecular changes that are associated with the phenotype,

  6. Different repellents for Aedes aegypti against blood-feeding and oviposition.

    Directory of Open Access Journals (Sweden)

    Ali Afify

    Full Text Available Methyl N,N-dimethyl anthranilate (MDA, ethyl anthranilate (EA and butyl anthranilate (BA were previously shown to repel Aedes aegypti mosquitoes from landing on human skin. However, the effect of these compounds on the orientation of flying mosquitoes in a choice situation and their effect on mosquito oviposition are not yet known. Here, we used a modified Y-tube olfactometer to test the effect of these compounds on the orientation of Aedes aegypti flying towards skin odor (human fingers, and we tested their effect on Aedes aegypti oviposition choice in a cage assay. In both behavioral situations we compared the effect to the well-documented repellent N,N-diethyl-meta-toluamide (DEET. MDA, EA, and DEET inhibited Aedes aegypti from flying towards skin odor while BA had no such effect. Conversely, MDA had no effect on oviposition while EA, BA, and DEET deterred oviposition, with the strongest effect observed for BA. Thus, we confirm that EA and DEET are generally repellent, while MDA is repellent only in a host-seeking context, and BA is deterrent only in an oviposition context. These compounds appear of potential use in mosquito control programs.

  7. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

    OpenAIRE

    São Thiago André Iwersen de; Kupek Emil; Ferreira Neto Joaquim Alves; São Thiago Paulo de Tarso

    2002-01-01

    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.

  8. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

    Directory of Open Access Journals (Sweden)

    São Thiago André Iwersen de

    2002-01-01

    Full Text Available 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.

  9. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Sao Thiago, André Iwersen de; Kupek, Emil; Ferreira Neto, Joaquim Alves; Sao Thiago, Paulo de Tarso

    2002-01-01

    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.

  10. Aedes aegypti (Diptera: culicidae) biting deterrence: structure-activity relationship of saturated and unsaturated fatty acids

    Science.gov (United States)

    In this study we systematically evaluated for the first time the biting deterrent effects of a series of saturated and unsaturated fatty acids against Aedes aegypti [yellow fever mosquito (Diptera: Culicidae)] using the K & D bioassay system (Klun et al 2005). The saturated fatty acids (C6:0 to C16...

  11. First report of naturally infected Aedes aegypti with chikungunya virus genotype ECSA in the Americas

    Science.gov (United States)

    Costa-da-Silva, André Luis; Ioshino, Rafaella Sayuri; Petersen, Vivian; Lima, Antonio Fernando; Cunha, Marielton dos Passos; Wiley, Michael R.; Ladner, Jason T.; Prieto, Karla; Palacios, Gustavo; Costa, Danuza Duarte; Suesdek, Lincoln; Zanotto, Paolo Marinho de Andrade

    2017-01-01

    Background The worldwide expansion of new emergent arboviruses such as Chikungunya and Zika reinforces the importance in understanding the role of mosquito species in spreading these pathogens in affected regions. This knowledge is essential for developing effective programs based on species specificity to avoid the establishment of endemic transmission cycles sustained by the identified local vectors. Although the first autochthonous transmission of Chikungunya virus was described in 2014 in the north of Brazil, the main outbreaks were reported in 2015 and 2016 in the northeast of Brazil. Methodology/Principal findings During 5 days of February 2016, we collected mosquitoes in homes of 6 neighborhoods of Aracaju city, the capital of Sergipe state. Four mosquito species were identified but Culex quinquefasciatus and Aedes aegypti were the most abundant. Field-caught mosquitoes were tested for Chikungunya (CHIKV), Zika (ZIKV) and Dengue viruses (DENV) by qRT-PCR and one CHIKV-infected Ae. aegypti female was detected. The complete sequence of CHIKV genome was obtained from this sample and phylogenetic analysis revealed that this isolate belongs to the East-Central-South-African (ECSA) genotype. Conclusions Our study describes the first identification of a naturally CHIKV-infected Ae. aegypti in Brazil and the first report of a CHIKV from ECSA genotype identified in this species in the Americas. These findings support the notion of Ae. aegypti being a vector involved in CHIKV outbreaks in northeast of Brazil. PMID:28614394

  12. First report of naturally infected Aedes aegypti with chikungunya virus genotype ECSA in the Americas.

    Directory of Open Access Journals (Sweden)

    André Luis Costa-da-Silva

    2017-06-01

    Full Text Available The worldwide expansion of new emergent arboviruses such as Chikungunya and Zika reinforces the importance in understanding the role of mosquito species in spreading these pathogens in affected regions. This knowledge is essential for developing effective programs based on species specificity to avoid the establishment of endemic transmission cycles sustained by the identified local vectors. Although the first autochthonous transmission of Chikungunya virus was described in 2014 in the north of Brazil, the main outbreaks were reported in 2015 and 2016 in the northeast of Brazil.During 5 days of February 2016, we collected mosquitoes in homes of 6 neighborhoods of Aracaju city, the capital of Sergipe state. Four mosquito species were identified but Culex quinquefasciatus and Aedes aegypti were the most abundant. Field-caught mosquitoes were tested for Chikungunya (CHIKV, Zika (ZIKV and Dengue viruses (DENV by qRT-PCR and one CHIKV-infected Ae. aegypti female was detected. The complete sequence of CHIKV genome was obtained from this sample and phylogenetic analysis revealed that this isolate belongs to the East-Central-South-African (ECSA genotype.Our study describes the first identification of a naturally CHIKV-infected Ae. aegypti in Brazil and the first report of a CHIKV from ECSA genotype identified in this species in the Americas. These findings support the notion of Ae. aegypti being a vector involved in CHIKV outbreaks in northeast of Brazil.

  13. First report of naturally infected Aedes aegypti with chikungunya virus genotype ECSA in the Americas.

    Science.gov (United States)

    Costa-da-Silva, André Luis; Ioshino, Rafaella Sayuri; Petersen, Vivian; Lima, Antonio Fernando; Cunha, Marielton Dos Passos; Wiley, Michael R; Ladner, Jason T; Prieto, Karla; Palacios, Gustavo; Costa, Danuza Duarte; Suesdek, Lincoln; Zanotto, Paolo Marinho de Andrade; Capurro, Margareth Lara

    2017-06-01

    The worldwide expansion of new emergent arboviruses such as Chikungunya and Zika reinforces the importance in understanding the role of mosquito species in spreading these pathogens in affected regions. This knowledge is essential for developing effective programs based on species specificity to avoid the establishment of endemic transmission cycles sustained by the identified local vectors. Although the first autochthonous transmission of Chikungunya virus was described in 2014 in the north of Brazil, the main outbreaks were reported in 2015 and 2016 in the northeast of Brazil. During 5 days of February 2016, we collected mosquitoes in homes of 6 neighborhoods of Aracaju city, the capital of Sergipe state. Four mosquito species were identified but Culex quinquefasciatus and Aedes aegypti were the most abundant. Field-caught mosquitoes were tested for Chikungunya (CHIKV), Zika (ZIKV) and Dengue viruses (DENV) by qRT-PCR and one CHIKV-infected Ae. aegypti female was detected. The complete sequence of CHIKV genome was obtained from this sample and phylogenetic analysis revealed that this isolate belongs to the East-Central-South-African (ECSA) genotype. Our study describes the first identification of a naturally CHIKV-infected Ae. aegypti in Brazil and the first report of a CHIKV from ECSA genotype identified in this species in the Americas. These findings support the notion of Ae. aegypti being a vector involved in CHIKV outbreaks in northeast of Brazil.

  14. Semaphorin-1a is required for Aedes aegypti embryonic nerve cord development.

    Directory of Open Access Journals (Sweden)

    Morgan Haugen

    Full Text Available Although mosquito genome projects have uncovered orthologues of many known developmental regulatory genes, extremely little is known about mosquito development. In this study, the role of semaphorin-1a (sema1a was investigated during vector mosquito embryonic ventral nerve cord development. Expression of sema1a and the plexin A (plexA receptor are detected in the embryonic ventral nerve cords of Aedes aegypti (dengue vector and Anopheles gambiae (malaria vector, suggesting that Sema1a signaling may regulate mosquito nervous system development. Analysis of sema1a function was investigated through siRNA-mediated knockdown in A. aegypti embryos. Knockdown of sema1a during A. aegypti development results in a number of nerve cord phenotypes, including thinning, breakage, and occasional fusion of the longitudinal connectives, thin or absent commissures, and general distortion of the nerve cord. Although analysis of Drosophila melanogaster sema1a loss-of-function mutants uncovered many similar phenotypes, aspects of the longitudinal phenotypes differed between D. melanogaster and A. aegypti. The results of this investigation suggest that Sema1a is required for development of the insect ventral nerve cord, but that the developmental roles of this guidance molecule have diverged in dipteran insects.

  15. First record of natural vertical transmission of dengue virus in Aedes aegypti from Cuba.

    Science.gov (United States)

    Gutiérrez-Bugallo, Gladys; Rodriguez-Roche, Rosmari; Díaz, Gisell; Vázquez, Antonio A; Alvarez, Mayling; Rodríguez, Magdalena; Bisset, Juan A; Guzman, Maria G

    2017-10-01

    While horizontal transmission (human-mosquito-human) of dengue viruses largely determines the epidemiology of the disease, vertical transmission (infected female mosquito- infected offspring) has been suggested as a mechanism that ensures maintenance of the virus during adverse conditions for horizontal transmission to occur. The purpose of this study was to analyze the natural infection of larval stages of Aedes aegypti (Diptera: Culicidae) with the dengue virus (DENV) in Cuba. Here, we report vertical transmission of DENV-3 genotype III in natural populations of Ae. aegypti through RT-PCR detection and serotyping plus sequencing. Our report constitutes the first record of vertical transmission of DENV in Ae. aegypti from Cuba with details of its serotype and genotype. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. The Aedes aegypti toll pathway controls dengue virus infection.

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    Zhiyong Xi

    2008-07-01

    Full Text Available Aedes aegypti, the mosquito vector of dengue viruses, utilizes its innate immune system to ward off a variety of pathogens, some of which can cause disease in humans. To date, the features of insects' innate immune defenses against viruses have mainly been studied in the fruit fly Drosophila melanogaster, which appears to utilize different immune pathways against different types of viruses, in addition to an RNA interference-based defense system. We have used the recently released whole-genome sequence of the Ae. aegypti mosquito, in combination with high-throughput gene expression and RNA interference (RNAi-based reverse genetic analyses, to characterize its response to dengue virus infection in different body compartments. We have further addressed the impact of the mosquito's endogenous microbial flora on virus infection. Our findings indicate a significant role for the Toll pathway in regulating resistance to dengue virus, as indicated by an infection-responsive regulation and functional assessment of several Toll pathway-associated genes. We have also shown that the mosquito's natural microbiota play a role in modulating the dengue virus infection, possibly through basal-level stimulation of the Toll immune pathway.

  17. Mosquito larvicidal and silver nanoparticles synthesis potential of plant latex

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    H.P. Borase

    2014-08-01

    Full Text Available Silver nanoparticles (AgNPs were synthesized from the latex of the medicinally important plants Euphorbia milii, Euphorbia hirta, Ficus racemosa and Jatropha curcas. Synthesized AgNPs were characterized by UV-Vis spectrophotometry, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, Fourier transformed infrared spectroscopy, particle size, and zeta potential analysis. Potency of latex and latex-synthesized AgNPs was evaluated against the 2nd and 4th instar larvae of Aedes aegypti and Anopheles stephensi. The lowest lethal concentration 50 (LC50 value among the different types of plant latex studied was observed for latex of E. milii (281.28±23.30 and 178.97±37.82 ppm, respectively against 2nd instar larvae of Ae. aegypti and An. stephensi. E. milii latex-synthesised AgNPs showed a high reduction in LC50 compared with its latex; i.e., 8.76±0.46 and 8.67±0.47 ppm, respectively, for 2nd instars of Ae. aegypti and An. stephensi. LC50 values of AgNPs synthesized using the latex of E. hirta, F. racemosa and J. curcas were lower than those of the latex of the respective plants; i.e., 10.77±0.53, 9.81±0.52, 12.06±0.60 and 8.79±0.51, 9.83±0.52, 9.60±0.51 ppm, respectively, for 2nd instars of An. stephensi and Ae. aegypti. Similarly, as compared with the plant latex, lower LC50 values were reported for latex-synthesized AgNPs against 4th instars of Ae. aegypt and An. stephensi. Results showed that all the types of plant latex investigated have the potential to convert silver nitrate into AgNPs showing a spectrum of potent mosquito larvicidal effects, indicating the possibility of further exploration of the bioefficacy of latex and latex-synthesized AgNPs against vectors of public health concerns.

  18. Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera: Culicidae).

    Science.gov (United States)

    Govindarajan, M; Mathivanan, T; Elumalai, K; Krishnappa, K; Anandan, A

    2011-01-01

    To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria (E. coronaria) and Caesalpinia pulcherrima (C. pulcherrima) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi). The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions. The hatch rates were assessed 48 h after treatment. The repellent efficacy was determined against three mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm(2) under the laboratory conditions. The crude extract of E. coronaria exerted zero hatchability (100% mortality) at 250, 200 and 150 ppm for Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The crude extract of C. pulcherrima exerted zero hatchability (100% mortality) at 375, 300 and 225 ppm for Cx. quinquefasciatus, Ae. aegypti and An. Stephensi, respectively. The methanol extract of E. coronaria found to be more repellenct than C. pulcherrima extract. A higher concentration of 5.0 mg/cm(2) provided 100% protection up to 150, 180 and 210 min against Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The results clearly showed that repellent activity was dose dependent. From the results it can be concluded the crude extracts of E. coronaria and C. pulcherrima are an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.

  19. Biocontrol evaluation of extracts and a major component, clusianone, from Clusia fluminensis Planch. & Triana against Aedes aegypti

    Science.gov (United States)

    Anholeti, Maria C; Duprat, Rodrigo C; Figueiredo, Maria R; Kaplan, Maria AC; Santos, Marcelo Guerra; Gonzalez, Marcelo S; Ratcliffe, Norman A; Feder, Denise; Paiva, Selma R; Mello, Cicero B

    2015-01-01

    Studies evaluated the effects of hexanic extracts from the fruits and flowers ofClusia fluminensis and the main component of the flower extract, a purified benzophenone (clusianone), against Aedes aegypti. The treatment of larvae with the crude fruit or flower extracts from C. fluminensis did not affect the survival ofAe. aegypti (50 mg/L), however, the flower extracts significantly delayed development of Ae. aegypti. In contrast, the clusianone (50 mg/L) isolate from the flower extract, representing 54.85% of this sample composition, showed a highly significant inhibition of survival, killing 93.3% of the larvae and completely blocking development of Ae. aegypti. The results showed, for the first time, high activity of clusianone against Ae. aegypti that both killed and inhibited mosquito development. Therefore, clusianone has potential for development as a biopesticide for controlling insect vectors of tropical diseases. Future work will elucidate the mode of action of clusianone isolated from C. fluminensis. PMID:26200711

  20. Attractive toxic sugar baits: control of mosquitoes with the low-risk active ingredient dinotefuran and potential impacts on nontarget organisms in Morocco.

    Science.gov (United States)

    Khallaayoune, Khalid; Qualls, Whitney A; Revay, Edita E; Allan, Sandra A; Arheart, Kristopher L; Kravchenko, Vasiliy D; Xue, Rui-De; Schlein, Yosef; Beier, John C; Müller, Günter C

    2013-10-01

    We evaluated the efficacy of attractive toxic sugar baits (ATSB) in the laboratory and field with the low-risk active ingredient dinotefuran against mosquito populations. Preliminary laboratory assays indicated that dinotefuran in solution with the sugar baits was ingested and resulted in high mortality of female Culex quinquefasciatus Say and Aedes aegypti Linnaeus. Field studies demonstrated >70% reduction of mosquito populations at 3 wk post-ATSB application. Nontarget feeding of seven insect orders-Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, Orthoptera, and Neuroptera-was evaluated in the field after application of attractive sugar baits (ASB) on vegetation by dissecting the guts and searching for food dye with a dissecting microscope. Nontargets were found stained with ASB 0.9% of the time when the application was applied on green nonflowering vegetation. Only two families were significantly impacted by the ASB application: Culicidae (mosquitoes) and Chironomidae (nonbiting midges) of the order Diptera. Pollinators of the other insect orders were not significantly impacted. No mortality was observed in the laboratory studies with predatory nontargets, wolf spiders or ground beetles, after feeding for 3 d on mosquitoes engorged on ATSB applied to vegetation. Overall, this novel control strategy had little impact on nontarget organisms, including pollinators and beneficial insects, and was effective at controlling mosquito populations, further supporting the development of ATSB for commercial use.

  1. EPA-Registered Repellents for Mosquitoes Transmitting Emerging Viral Disease.

    Science.gov (United States)

    Patel, Radha V; Shaeer, Kristy M; Patel, Pooja; Garmaza, Aleksey; Wiangkham, Kornwalee; Franks, Rachel B; Pane, Olivia; Carris, Nicholas W

    2016-12-01

    In many parts of the United States, mosquitoes were previously nuisance pests. However, they now represent a potential threat in the spread of viral diseases. The Aedes aegypti, Aedes albopictus, and Culex species mosquitoes are endemic to the United States and together may transmit a variety of viral diseases of growing concern, including West Nile virus, chikungunya, dengue fever, and Zika virus. The Centers for Disease Control and Prevention and the Environmental Protection Agency (EPA) recommend N,N-diethyl-meta-toluamide (DEET) as a first-line mosquito repellent, but for patients refusing to use DEET or other conventional repellents, guidance is limited to any EPA-registered product. Therefore, we conducted a systematic review of the literature to identify which EPA-registered personal mosquito repellent provides the best protection from A. aegypti, A. albopictus, and Culex spp. mosquitoes. We abstracted data from 62 published reports of EPA-registered mosquito repellents. The conventional repellent picaridin has the strongest data to support its use as a second-line agent, while IR3535 and oil of lemon eucalyptus are reasonably effective natural products. Citronella, catnip, and 2-undecanone offer limited protection or have limited data. These results can be used by pharmacists and other health care professionals to advise patients on the selection of an EPA-registered mosquito repellent. Regardless of the repellent chosen, it is vital for patients to follow all instructions/precautions in the product labeling to ensure safe and effective use. © 2016 Pharmacotherapy Publications, Inc.

  2. MicroRNA-275 targets sarco/endoplasmic reticulum Ca2+ adenosine triphosphatase (SERCA to control key functions in the mosquito gut.

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    Bo Zhao

    2017-08-01

    Full Text Available The yellow fever mosquito Aedes aegypti is the major vector of arboviruses, causing numerous devastating human diseases, such as dengue and yellow fevers, Chikungunya and Zika. Female mosquitoes need vertebrate blood for egg development, and repeated cycles of blood feeding are tightly linked to pathogen transmission. The mosquito's posterior midgut (gut is involved in blood digestion and also serves as an entry point for pathogens. Thus, the mosquito gut is an important tissue to investigate. The miRNA aae-miR-275 (miR-275 has been shown to be required for normal blood digestion in the female mosquito; however, the mechanism of its action has remained unknown. Here, we demonstrate that miR-275 directly targets and positively regulates sarco/endoplasmic reticulum Ca2+ adenosine triphosphatase, which is implicated in active transport of Ca2+ from the cytosol to the sarco/endoplasmic reticulum. We utilized a combination of the gut-specific yeast transcription activator protein Gal4/upstream activating sequence (Gal4/UAS system and miRNA Tough Decoy technology to deplete the endogenous level of miR-275 in guts of transgenic mosquitoes. This gut-specific reduction of miR-275 post blood meal decreased SERCA mRNA and protein levels of the digestive enzyme late trypsin. It also resulted in a significant reduction of gut microbiota. Moreover, the decrease of miR-275 and SERCA correlated with defects in the Notch signaling pathway and assembly of the gut actin cytoskeleton. The adverse phenotypes caused by miR-275 silencing were rescued by injections of miR-275 mimic. Thus, we have discovered that miR-275 directly targets SERCA, and the maintenance of its level is critical for multiple gut functions in mosquitoes.

  3. Permethrin-Treated Clothing as Protection against the Dengue Vector, Aedes aegypti: Extent and Duration of Protection.

    Science.gov (United States)

    DeRaedt Banks, Sarah; Orsborne, James; Gezan, Salvador A; Kaur, Harparkash; Wilder-Smith, Annelies; Lindsey, Steve W; Logan, James G

    2015-01-01

    Dengue transmission by the mosquito vector, Aedes aegypti, occurs indoors and outdoors during the day. Personal protection of individuals, particularly when outside, is challenging. Here we assess the efficacy and durability of different types of insecticide-treated clothing on laboratory-reared Ae. aegypti. Standardised World Health Organisation Pesticide Evaluation Scheme (WHOPES) cone tests and arm-in-cage assays were used to assess knockdown (KD) and mortality of Ae. aegypti tested against factory-treated fabric, home-dipped fabric and microencapsulated fabric. Based on the testing of these three different treatment types, the most protective was selected for further analysis using arm-in cage assays with the effect of washing, ultra-violet light, and ironing investigated using high pressure liquid chromatography. Efficacy varied between the microencapsulated and factory dipped fabrics in cone testing. Factory-dipped clothing showed the greatest effect on KD (3 min 38.1%; 1 hour 96.5%) and mortality (97.1%) with no significant difference between this and the factory dipped school uniforms. Factory-dipped clothing was therefore selected for further testing. Factory dipped clothing provided 59% (95% CI = 49.2%- 66.9%) reduction in landing and a 100% reduction in biting in arm-in-cage tests. Washing duration and technique had a significant effect, with insecticidal longevity shown to be greater with machine washing (LW50 = 33.4) compared to simulated hand washing (LW50 = 17.6). Ironing significantly reduced permethrin content after 1 week of simulated use, with a 96.7% decrease after 3 months although UV exposure did not reduce permethrin content within clothing significantly after 3 months simulated use. Permethrin-treated clothing may be a promising intervention in reducing dengue transmission. However, our findings also suggest that clothing may provide only short-term protection due to the effect of washing and ironing, highlighting the need for improved

  4. Permethrin-Treated Clothing as Protection against the Dengue Vector, Aedes aegypti: Extent and Duration of Protection.

    Directory of Open Access Journals (Sweden)

    Sarah DeRaedt Banks

    Full Text Available Dengue transmission by the mosquito vector, Aedes aegypti, occurs indoors and outdoors during the day. Personal protection of individuals, particularly when outside, is challenging. Here we assess the efficacy and durability of different types of insecticide-treated clothing on laboratory-reared Ae. aegypti.Standardised World Health Organisation Pesticide Evaluation Scheme (WHOPES cone tests and arm-in-cage assays were used to assess knockdown (KD and mortality of Ae. aegypti tested against factory-treated fabric, home-dipped fabric and microencapsulated fabric. Based on the testing of these three different treatment types, the most protective was selected for further analysis using arm-in cage assays with the effect of washing, ultra-violet light, and ironing investigated using high pressure liquid chromatography.Efficacy varied between the microencapsulated and factory dipped fabrics in cone testing. Factory-dipped clothing showed the greatest effect on KD (3 min 38.1%; 1 hour 96.5% and mortality (97.1% with no significant difference between this and the factory dipped school uniforms. Factory-dipped clothing was therefore selected for further testing. Factory dipped clothing provided 59% (95% CI = 49.2%- 66.9% reduction in landing and a 100% reduction in biting in arm-in-cage tests. Washing duration and technique had a significant effect, with insecticidal longevity shown to be greater with machine washing (LW50 = 33.4 compared to simulated hand washing (LW50 = 17.6. Ironing significantly reduced permethrin content after 1 week of simulated use, with a 96.7% decrease after 3 months although UV exposure did not reduce permethrin content within clothing significantly after 3 months simulated use.Permethrin-treated clothing may be a promising intervention in reducing dengue transmission. However, our findings also suggest that clothing may provide only short-term protection due to the effect of washing and ironing, highlighting the need for

  5. New State Records of Mosquitoes for Colorado.

    Science.gov (United States)

    Rose, Dominic A; Kondratieff, B C; Weissmann, M J

    2015-06-01

    The 1967 treatment of the Mosquitoes of Colorado by Harmston and Lawson and subsequent publications have recorded 46 culicid species from Colorado. As part of a study to create an updated synopsis of the mosquitoes of Colorado, adult trapping at numerous localities was conducted in Colorado during the summers of 2013 and 2014. This review also included an examination of mosquito specimens in various relevant museum collections. Aedes (Ochlerotatus) niphadopsis and Ae. (Och.) spencerii spencerii were collected during the 2013 and 2014 field seasons. Records for Ae. (Och.) canadensis canadensis, Ae. (Stegomyia) aegypti, and Uranotaenia (Pseudoficalbia) anhydor syntheta were obtained from examination of museum specimens. These species constitute new state records for Colorado, with 51 species now known from the state.

  6. Aktivitas enzim monooksigenase pada populasi nyamuk Aedes aegypti di Kecamatan Tembalang, Kota Semarang

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    Dyah Widiastuti

    2015-06-01

    Full Text Available Abstract. Dengue Haemorrhagic Fever (DHF is a major health problem in Tembalang sub district, Semarang City. Fogging with insecticide applications was done frequently as an effort to control Dengue vectors. The use of insecticides from the same class in a long time can lead to resistance in mosquitos’ population. The research aimed to observe the activity of monooxygenases in Aedes aegypti populations in Tembalang Subdistrict, Semarang. The study was conducted during February-November 2014 with a cross-sectional design in 10 villages in Tembalang Subdistirict, Semarang City. Field strains of Ae. aegypti eggs were collected using ovitraps. The collected eggs were grown under standard condition to adult mosquitoes. Mosquitos’ homogenate were stored at -85°C and used for biochemical assays. The results showed there was increased monooxygenases activity in Ae. aegypti populations. Resistance to synthetic pyrethroid insecticide in Ae. aegypti mosquitoes population in Tembalang Subdistrict might be caused by the mechanism of detoxification enzymes in particular monooxygenases Keywords: monooxygenase, insecticide, Ae. aegypti, resistance  Abstrak. Demam Berdarah Dengue (DBD masih menjadi masalah kesehatan utama di Kecamatan Tembalang, Kota Semarang. Tindakan fogging untuk pengendalian vektor DBD sering dilakukan. Penggunaan insektisida dari golongan yang sama dalam waktu cukup lama dapat memicu terjadinya resistensi. Tujuan penelitian untuk mengamati aktivitas enzim monooksigenase pada populasi nyamuk Aedes aegypti di Kecamatan Tembalang, Kota Semarang. Penelitian dilaksanakan bulan Februari-November 2014 dengan desain potong lintang di 10 desa di Kecamatan Tembalang, Kota Semarang. Pada penelitian ini dilakukan pemasangan ovitrap untuk mendapatkan sampel telur yang dipelihara menjadi nyamuk dewasa. Sampel homogenate nyamuk disimpan pada suhu -85°C, selanjutnya dilakukan peng-ujian resistensi dengan uji biokimia untuk melihat aktivitas enzim

  7. Bacterial Larvicide, Bacillus thuringiensis israelensis Strain AM 65-52 Water Dispersible Granule Formulation Impacts Both Dengue Vector, Aedes aegypti (L.) Population Density and Disease Transmission in Cambodia.

    Science.gov (United States)

    Setha, To; Chantha, Ngan; Benjamin, Seleena; Socheat, Doung

    2016-09-01

    A multi-phased study was conducted in Cambodia from 2005-2011 to measure the impact of larviciding with the bacterial larvicide, Bacillus thuringiensis israelensis (Bti), a water dispersible granule (WG) formulation on the vector, Aedes aegypti (L.) and the epidemiology. In our studies, all in-use containers were treated at 8 g/1000 L, including smaller containers and animal feeders which were found to contribute 23% of Ae aegypti pupae. The treated waters were subjected to routine water exchange activities. Pupal production was suppressed by an average 91% for 8 weeks. Pupal numbers continued to remain significantly lower than the untreated commune (UTC) for 13 weeks post treatment in the peak dengue vector season (ptreated commune. An average 70% of the household harbored 0-5 Ae aegypti mosquitoes per home for 8 weeks post treatment, but in the same period of time >50% of the household in the UTC harbored ≥11 mosquitoes per home. The adult population continued to remain at significantly much lower numbers in the Bti treated commune than in the UTC for 10-12 weeks post treatment (ptreatment in the 6 months monsoon season with complete coverage of the target districts achieved an overall dengue case reduction of 48% in the 6 treated districts compared to the previous year, 2010. Five untreated districts in the same province had an overwhelming increase of 352% of dengue cases during the same period of time. The larvicide efficacy, treatment of all in-use containers at the start of the monsoon season, together with treatment coverage of entire districts interrupted disease transmission in the temephos resistant province.

  8. Mosquito infection responses to developing filarial worms.

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    Sara M Erickson

    2009-10-01

    Full Text Available Human lymphatic filariasis is a mosquito-vectored disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and Brugia timori. These are relatively large roundworms that can cause considerable damage in compatible mosquito vectors. In order to assess how mosquitoes respond to infection in compatible mosquito-filarial worm associations, microarray analysis was used to evaluate transcriptome changes in Aedes aegypti at various times during B. malayi development. Changes in transcript abundance in response to the different stages of B. malayi infection were diverse. At the early stages of midgut and thoracic muscle cell penetration, a greater number of genes were repressed compared to those that were induced (20 vs. 8. The non-feeding, intracellular first-stage larvae elicited few differences, with 4 transcripts showing an increased and 9 a decreased abundance relative to controls. Several cecropin transcripts increased in abundance after parasites molted to second-stage larvae. However, the greatest number of transcripts changed in abundance after larvae molted to third-stage larvae and migrated to the head and proboscis (120 induced, 38 repressed, including a large number of putative, immunity-related genes (approximately 13% of genes with predicted functions. To test whether the innate immune system of mosquitoes was capable of modulating permissiveness to the parasite, we activated the Toll and Imd pathway controlled rel family transcription factors Rel1 and Rel2 (by RNA interference knockdown of the pathway's negative regulators Cactus and Caspar during the early stages of infection with B. malayi. The activation of either of these immune signaling pathways, or knockdown of the Toll pathway, did not affect B. malayi in Ae. aegypti. The possibility of LF parasites evading mosquito immune responses during successful development is discussed.

  9. Repellent activity of herbal essential oils against Aedes aegypti (Linn. and Culex quinquefasciatus (Say.

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    Duangkamon Sritabutra

    2013-08-01

    Full Text Available Objective: To determine the mosquito repellent activity of herbal essential oils against female Aedes aegypti and Culex quinquefasciatus. Methods: On a volunteer’s forearm, 0.1 mL of each essential oil was applied to 3 cm伊10 cm of exposed skin. The protection time was recorded for 3 min after every 30 min. Results: Essential oil from clove oil in olive oil and in coconut oil gave the longest lasting period of 76.50 min and 96.00 min respectively against Aedes aegypti. The citronella grass oil in olive oil, citronella grass oil in coconut oil and lemongrass oil in coconut oil exhibited protection against Culex quinquefasciatus at 165.00, 105.00, and 112.50 min respectively. Conclusions: The results clearly indicated that clove, citronella and lemongrass oil were the most promising for repellency against mosquito species. These oils could be used to develop a new formulation to control mosquitoes.

  10. Repellent activity of herbal essential oils against Aedes aegypti (Linn.) and Culex quinquefasciatus (Say.)

    Science.gov (United States)

    Sritabutra, Duangkamon; Soonwera, Mayura

    2013-01-01

    Objective To determine the mosquito repellent activity of herbal essential oils against female Aedes aegypti and Culex quinquefasciatus. Methods On a volunteer's forearm, 0.1 mL of each essential oil was applied to 3 cm×10 cm of exposed skin. The protection time was recorded for 3 min after every 30 min. Results Essential oil from clove oil in olive oil and in coconut oil gave the longest lasting period of 76.50 min and 96.00 min respectively against Aedes aegypti. The citronella grass oil in olive oil, citronella grass oil in coconut oil and lemongrass oil in coconut oil exhibited protection against Culex quinquefasciatus at 165.00, 105.00, and 112.50 min respectively. Conclusions The results clearly indicated that clove, citronella and lemongrass oil were the most promising for repellency against mosquito species. These oils could be used to develop a new formulation to control mosquitoes.

  11. Assessing the feasibility of controlling Aedes aegypti with transgenic methods: a model-based evaluation.

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    Mathieu Legros

    Full Text Available Suppression of dengue and malaria through releases of genetically engineered mosquitoes might soon become feasible. Aedes aegypti mosquitoes carrying a conditionally lethal transgene have recently been used to suppress local vector populations in small-scale field releases. Prior to releases of transgenic insects on a wider scale, however, most regulatory authorities will require additional evidence that suppression will be effective in natural heterogeneous habitats. We use a spatially explicit stochastic model of an Ae. aegypti population in Iquitos, Peru, along with an uncertainty analysis of its predictions, to quantitatively assess the outcome of varied operational approaches for releases of transgenic strains with conditional death of females. We show that population elimination might be an unrealistic objective in heterogeneous populations. We demonstrate that substantial suppression can nonetheless be achieved if releases are deployed in a uniform spatial pattern using strains combining multiple lethal elements, illustrating the importance of detailed spatial models for guiding genetic mosquito control strategies.

  12. Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein.

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    Berlin Londono-Renteria

    2015-10-01

    Full Text Available Dengue virus (DENV is a mosquito-borne flavivirus that causes serious human disease and mortality worldwide. There is no specific antiviral therapy or vaccine for DENV infection. Alterations in gene expression during DENV infection of the mosquito and the impact of these changes on virus infection are important events to investigate in hopes of creating new treatments and vaccines. We previously identified 203 genes that were ≥5-fold differentially upregulated during flavivirus infection of the mosquito. Here, we examined the impact of silencing 100 of the most highly upregulated gene targets on DENV infection in its mosquito vector. We identified 20 genes that reduced DENV infection by at least 60% when silenced. We focused on one gene, a putative cysteine rich venom protein (SeqID AAEL000379; CRVP379, whose silencing significantly reduced DENV infection in Aedes aegypti cells. Here, we examine the requirement for CRVP379 during DENV infection of the mosquito and investigate the mechanisms surrounding this phenomenon. We also show that blocking CRVP379 protein with either RNAi or specific antisera inhibits DENV infection in Aedes aegypti. This work identifies a novel mosquito gene target for controlling DENV infection in mosquitoes that may also be used to develop broad preventative and therapeutic measures for multiple flaviviruses.

  13. Larval stress alters dengue virus susceptibility in Aedes aegypti (L.) adult females.

    Science.gov (United States)

    Kang, David S; Alcalay, Yehonatan; Lovin, Diane D; Cunningham, Joanne M; Eng, Matthew W; Chadee, Dave D; Severson, David W

    2017-10-01

    In addition to genetic history, environmental conditions during larval stages are critical to the development, success and phenotypic fate of the Aedes aegypti mosquito. In particular, previous studies have shown a strong genotype-by-environment component to adult mosquito body size in response to optimal vs stressed larval conditions. Here, we expand upon those results by investigating the effects of larval-stage crowding and nutritional limitation on the susceptibility of a recent field isolate of Aedes aegypti to dengue virus serotype-2. Interestingly, female mosquitoes from larvae subjected to a stressed regime exhibited significantly reduced susceptibility to disseminated dengue infection 14days post infection compared to those subjected to optimal regimes. Short term survivorship post-infected blood feeding was not significantly different. As with body size, dengue virus susceptibility of a mosquito population is determined by a combination of genetic and environmental factors and is likely maintained by balancing selection. Here, we provide evidence that under different environmental conditions, the innate immune response of field-reared mosquitoes exhibits a large range of phenotypic variability with regard to dengue virus susceptibility. Further, as with body size, our results suggest that mosquitoes reared under optimal laboratory conditions, as employed in all mosquito-pathogen studies to date, may not always be realistic proxies for natural populations. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Aedes (Stegomyia) aegypti in the continental United States: a vector at the cool margin of its geographic range.

    Science.gov (United States)

    Eisen, Lars; Moore, Chester G

    2013-05-01

    After more than a half century without recognized local dengue outbreaks in the continental United States, there were recent outbreaks of autochthonous dengue in the southern parts of Texas (2004-2005) and Florida (2009-2011). This dengue reemergence has provoked interest in the extent of the future threat posed by the yellow fever mosquito, Aedes (Stegomyia) aegypti (L.), the primary vector of dengue and yellow fever viruses in urban settings, to human health in the continental United States. Ae. aegypti is an intriguing example of a vector species that not only occurs in the southernmost portions of the eastern United States today but also is incriminated as the likely primary vector in historical outbreaks of yellow fever as far north as New York, Philadelphia, and Boston, from the 1690s to the 1820s. For vector species with geographic ranges limited, in part, by low temperature and cool range margins occurring in the southern part of the continental United States, as is currently the case for Ae. aegypti, it is tempting to speculate that climate warming may result in a northward range expansion (similar to that seen for Ixodes tick vectors of Lyme borreliosis spirochetes in Scandinavia and southern Canada in recent decades). Although there is no doubt that climate conditions directly impact many aspects of the life history of Ae. aegypti, this mosquito also is closely linked to the human environment and directly influenced by the availability of water-holding containers for oviposition and larval development. Competition with other container-inhabiting mosquito species, particularly Aedes (Stegomyia) albopictus (Skuse), also may impact the presence and local abundance of Ae. aegypti. Field-based studies that focus solely on the impact of weather or climate factors on the presence and abundance of Ae. aegypti, including assessments of the potential impact of climate warming on the mosquito's future range and abundance, do not consider the potential confounding

  15. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania.

    Science.gov (United States)

    Mweya, Clement N; Kimera, Sharadhuli I; Mellau, Lesakit S B; Mboera, Leonard E G

    2015-01-01

    Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC) light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. A total of 1,823 mosquitoes were collected, of which 87% (N=1,588) were Culex pipiens complex, 12% (N=226) Aedes aegypti, and 0.5% (N=9) Anopheles species. About two-thirds (67%; N=1,095) of C. pipiens complex and nearly 100% (N=225) of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78%) of C. pipiens complex and most (85%) of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  16. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

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    Clement N. Mweya

    2015-01-01

    Full Text Available Background: Rift Valley fever (RVF is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results: A total of 1,823 mosquitoes were collected, of which 87% (N=1,588 were Culex pipiens complex, 12% (N=226 Aedes aegypti, and 0.5% (N=9 Anopheles species. About two-thirds (67%; N=1,095 of C. pipiens complex and nearly 100% (N=225 of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78% of C. pipiens complex and most (85% of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions: These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  17. The combination of the entomopathogenic fungus Metarhizium anisopliae with the insecticide Imidacloprid increases virulence against the dengue vector Aedes aegypti (Diptera: Culicidae

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    Samuels Richard I

    2011-01-01

    Full Text Available Abstract Background Dengue fever transmitted by the mosquito Aedes aegypti, is one of the most rapidly spreading insect borne diseases, stimulating the search for alternatives to current control measures. The dengue vector A. aegypti has received less attention than anophelene species, although more than 2.5 billion people are at risk of infection worldwide. Entomopathogenic fungi are emerging as potential candidates for the control of mosquitoes. Here we continue our studies on the pathogenicity of the entomopathogenic fungus Metarhizium anisopliae against adult A. aegypti females. With the aim of further reducing mean survival times of A. aegypti exposed to fungus impregnated surfaces, a sub-lethal concentration of the neonicotinoid insecticide Imidacloprid (IMI was added to fungal suspensions. Results A sub-lethal concentration of IMI that did not significantly alter the daily survival rates or mean survival percentages of mosquitoes was identified to be 0.1 ppm. This sub-lethal concentration was combined with M. anisopliae conidia (1 × 109 conidia mL-1. Both the combined treatment and the conidia alone were able to reduce the survival of A. aegypti compared with untreated or IMI treated mosquitoes. Importantly, mosquito survival following exposure to the combined treatment for 6 and 12 hrs was significantly reduced when compared with mosquitoes exposed to conidia alone. Conclusions This is the first time that a combination of an insecticide and an entomopathogenic fungus has been tested against A. aegypti. Firstly, the study showed the potential of IMI as an alternative to the currently employed pyrethroid adulticides. Secondly, as an alternative to applications of high concentrations of chemical insecticides, we suggest that adult A. aegypti could be controlled by surface application of entomopathogenic fungi and that the efficiency of these fungi could be increased by combining the fungi with ultra-low concentrations of insecticides

  18. A cross-sectional survey of Aedes aegypti immature abundance in urban and rural household containers in central Colombia.

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    Overgaard, Hans J; Olano, Víctor Alberto; Jaramillo, Juan Felipe; Matiz, María Inés; Sarmiento, Diana; Stenström, Thor Axel; Alexander, Neal

    2017-07-27

    Aedes aegypti, the major vector of dengue, breeds in domestic water containers. The development of immature mosquitoes in such containers is influenced by various environmental, ecological and socioeconomic factors. Urban and rural disparities in water storage practices and water source supply may affect mosquito immature abundance and, potentially, dengue risk. We evaluated the effect of water and container characteristics on A. aegypti immature abundance in urban and rural areas. Data were collected in the wet season of 2011 in central Colombia from 36 urban and 35 rural containers, which were either mosquito-positive or negative. Immature mosquitoes were identified to species. Data on water and container characteristics were collected from all containers. A total of 1452 Aedes pupae and larvae were collected of which 81% were A. aegypti and 19% A. fluviatilis. Aedes aegypti immatures were found in both urban and rural sites. However, the mean number of A. aegypti pupae was five times higher in containers in the urban sites compared to those in the rural sites. One of the important factors associated with A. aegypti infestation was frequency of container washing. Monthly-washed or never-washed containers were both about four times more likely to be infested than those washed every week. There were no significant differences between urban and rural sites in frequency of washing containers. Aedes aegypti immature infestation was positively associated with total dissolved solids, but negatively associated with dissolved oxygen. Water temperature, total dissolved solids, ammonia, nitrate, and organic matter were significantly higher in urban than in rural containers, which might explain urban-rural differences in breeding of A. aegypti. However, many of these factors vary substantially between studies and in their degree of association with vector breeding, therefore they may not be reliable indices for vector control interventions. Although containers in urban areas

  19. Especificidade da armadilha Adultrap para capturar fêmeas de Aedes aegypti (Diptera: Culicidae Specificity of the Adultrap for capturing females of Aedes aegypti (Diptera: Culicidae

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    Almério de Castro Gomes

    2007-04-01

    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.

  20. The Eye of the Tiger, the Thrill of the Fight: Effective Larval and Adult Control Measures Against the Asian Tiger Mosquito, Aedes albopictus (Diptera: Culicidae), in North America.

    Science.gov (United States)

    Faraji, Ary; Unlu, Isik

    2016-09-01

    The Asian tiger mosquito, Aedes albopictus (Skuse), is a highly invasive container-inhabiting species with a global distribution. This mosquito, similar to other Stegomyia species such as Aedes aegypti (L.), is highly adapted to urban and suburban areas, and commonly oviposits in artificial containers, which are ubiquitous in these peridomestic environments. The increase in speed and amount of international travel and commerce, coupled with global climate change, have aided in the resurgence and expansion of Stegomyia species into new areas of North America. In many parts of their range, both species are implicated as significant vectors of emerging and re-emerging arboviruses such as dengue, chikungunya, and now Zika. Although rapid and major advances have been made in the field of biology, ecology, genetics, taxonomy, and virology, relatively little has changed in the field of mosquito control in recent decades. This is particularly discouraging in regards to container-inhabiting mosquitoes, because traditional integrated mosquito management (IMM) approaches have not been effective against these species. Many mosquito control programs simply do not possess the man-power or necessary financial resources needed to suppress Ae. albopictus effectively. Therefore, control of mosquito larvae, which is the foundation of IMM approaches, is exceptionally difficult over large areas. This review paper addresses larval habitats, use of geographic information systems for habitat preference detection, door-to-door control efforts, source reduction, direct application of larvicides, biological control agents, area-wide low-volume application of larvicides, hot spot treatments, autodissemination stations, public education, adult traps, attractive-toxic sugar bait methods, lethal ovitraps, barrier-residual adulticides, hand-held ultra-low-volume adulticides, area-wide adulticides applied by ground or air, and genetic control methods. The review concludes with future

  1. Susceptibility of Indigenous and Transplanted Mosquito Spp. to Dengue Virus in Japan.

    Science.gov (United States)

    Sasaki, Toshinori; Higa, Yukiko; Bertuso, Arlene G; Isawa, Haruhiko; Takasaki, Tomohiko; Minakawa, Noboru; Sawabe, Kyoko

    2015-01-01

    Dengue fever, an acute, mosquito-borne, febrile illness caused by Flavivirus spp., is a problem in Africa, South and Southeast Asia, Latin America, and the Caribbean. A dengue outbreak occurred after nearly 70 years of absence or no detection, and then 158 autochthonous cases occurred in Japan from August to October 15, 2014. The most competent mosquito vectors for dengue virus transmission were Aedes aegypti and A. albopictus. Since A. albopictus is widely distributed across Japan and A. aegypti recently invaded Japan by airplane, we examined the susceptibility of these species to infection by dengue virus.

  2. Gene vector and transposable element behavior in mosquitoes.

    Science.gov (United States)

    O'Brochta, David A; Sethuraman, Nagaraja; Wilson, Raymond; Hice, Robert H; Pinkerton, Alexandra C; Levesque, Cynthia S; Bideshi, Dennis K; Jasinskiene, Nijole; Coates, Craig J; James, Anthony A; Lehane, Michael J; Atkinson, Peter W

    2003-11-01

    The development of efficient germ-line transformation technologies for mosquitoes has increased the ability of entomologists to find, isolate and analyze genes. The utility of the currently available systems will be determined by a number of factors including the behavior of the gene vectors during the initial integration event and their behavior after chromosomal integration. Post-integration behavior will determine whether the transposable elements being employed currently as primary gene vectors will be useful as gene-tagging and enhancer-trapping agents. The post-integration behavior of existing insect vectors has not been extensively examined. Mos1 is useful as a primary germ-line transformation vector in insects but is inefficiently remobilized in Drosophila melanogaster and Aedes aegypti. Hermes transforms D. melanogaster efficiently and can be remobilized in this species. This element is also useful for creating transgenic A. aegypti, but its mode of integration in mosquitoes results in the insertion of flanking plasmid DNA. Hermes can be remobilized in the soma of A. aegypti and transposes using a common cut-and-paste mechanism; however, the element does not remobilize in the germ line. piggyBac can be used to create transgenic mosquitoes and occasionally integrates using a mechanism other than a simple cut-and-paste mechanism. Preliminary data suggest that remobilization is infrequent. Minos also functions in mosquitoes and, like the other gene vectors, appears to remobilize inefficiently following integration. These results have implications for future gene vector development efforts and applications.

  3. Genome Investigations of Vector Competence in Aedes aegypti to Inform Novel Arbovirus Disease Control Approaches

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    David W. Severson

    2016-10-01

    Full Text Available Dengue (DENV, yellow fever, chikungunya, and Zika virus transmission to humans by a mosquito host is confounded by both intrinsic and extrinsic variables. Besides virulence factors of the individual arboviruses, likelihood of virus transmission is subject to variability in the genome of the primary mosquito vector, Aedes aegypti. The “vectorial capacity” of A. aegypti varies depending upon its density, biting rate, and survival rate, as well as its intrinsic ability to acquire, host and transmit a given arbovirus. This intrinsic ability is known as “vector competence”. Based on whole transcriptome analysis, several genes and pathways have been predicated to have an association with a susceptible or refractory response in A. aegypti to DENV infection. However, the functional genomics of vector competence of A. aegypti is not well understood, primarily due to lack of integrative approaches in genomic or transcriptomic studies. In this review, we focus on the present status of genomics studies of DENV vector competence in A. aegypti as limited information is available relative to the other arboviruses. We propose future areas of research needed to facilitate the integration of vector and virus genomics and environmental factors to work towards better understanding of vector competence and vectorial capacity in natural conditions.

  4. EFEKTIVITAS PEMANASAN KELAMBU BERINSEKTISIDA, OLYSET TERHADAP NYAMUK AEDES AEGYPTI (DIPTERA: CULICIDAE

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    Upik Kesumawati Hadi

    2012-11-01

    Full Text Available The aim of this research was to know the effectiveness of heating insecticide bednet, against the mosquito Aedes aegypti. As many as 240 Olyset samples from eleven health centers in Bangka District were tested its effectiveness against mosquitoes with WHO ball test method. In these test, there were used 25 Aedes aegypti female, and 3-5 days old. Bednet sample treatments was collected from six health centreareas that the people washed and heated the nets. Control samples was taken from five health centre areas where the people only washed their nets without heating. Sample collections were done for four periods with interval time of three months, from September 2007 to June 2008. The observation on knockdown effect/mortality of Aedes aegypti was done on 30 minutes, 60 minutes, and 24 hours after 3 minutes exposured. The effectiveness of Olyset bed net was based on the value of knock-down time 50% (KT-50. The result showed that the difference of the average percentage mortality of Aedes aegypti after 30 minutes, 60 minutes and 24 hours exposured on period of I, II, III and IV in the control groups and on the treatment groups were not significant enough. However, based on the value of KT-50, the heat regeneration on Olyset net has a better effectiveness compared with the control (P<0,05. Keywords: Olyset, long-lasting insecticidal net, Aedes aegypti, heat regeneration

  5. Oviposition and Embryotoxicity of Indigofera suffruticosa on Early Development of Aedes aegypti (Diptera: Culicidae

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    Jeymesson Raphael Cardoso Vieira

    2012-01-01

    Full Text Available Aqueous extract of Indigofera suffruticosa leaves obtained by infusion was used to evaluate the oviposition, its effect on development of eggs and larvae, and morphological changes in larvae of Aedes aegypti. The bioassays were carried out with aqueous extract in different concentrations on eggs, larvae, and female mosquitoes, and the morphological changes were observed in midgut of larvae. The extract showed repellent activity on A. aegypti mosquitoes, reducing significantly the egg laying by females with control substrate (343 (185–406 compared with the treated substrate (88 (13–210. No eclosion of A. aegypti eggs at different concentrations studied was observed. The controleclodedin 35%. At concentration of 250 μg/mL, 93.3% of larvae remained in the second instar of development and at concentrations of 500, 750, and 1000 μg/mL the inhibitory effect was lower with percentages of 20%, 53.3%, and 46.6%, respectively. Morphological changes like disruption on the peritrophic envelope (PE, discontinued underlying epithelium, increased gut lumen, and segments with hypertrophic aspects were observed in anterior region of medium midgut of larvae of A. aegypti. The results showed repellent activity, specific embryotoxicity, and general growth retardation in A. aegypti by medium containing aqueous extract of I. suffruticosa leaves.

  6. Effects of Irritant Chemicals on Aedes aegypti Resting Behavior: Is There a Simple Shift to Untreated Safe Sites?

    Science.gov (United States)

    2011-07-26

    yahoo.fr Introduction Dengue, primarily transmitted by Aedes aegypti (L.) ( Diptera : Culicidae), is presently the most important mosquito-borne viral...significantly attracted by black [18], yellow, orange and red colors [19]. Studies that have exploited Ae. aegypti’s attraction to color contrast (i.e...simultaneous presentation of two colors, one which mosquitoes are attracted to in order to direct them to a target) have led to the development of host

  7. Manipulating insulin signaling to enhance mosquito reproduction

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    Rasgon Jason L

    2009-08-01

    Full Text Available Abstract Backgrond In the mosquito Aedes aegypti the insulin/insulin growth factor I signaling (IIS cascade is a key regulator of many physiological processes, including reproduction. Two important reproductive events, steroidogenesis in the ovary and yolk synthesis in the fat body, are regulated by the IIS cascade in mosquitoes. The signaling molecule phosphatase and tensin homolog (PTEN is a key inhibitor of the IIS cascade that helps modulate the activity of the IIS cascade. In Ae. aegypti, six unique splice variants of AaegPTEN were previously identified, but the role of these splice variants, particularly AaegPTEN3 and 6, were unknown. Results Knockdown of AaegPTEN or its specific splice variant AaegPTEN6 (the splice variant thought to regulate reproduction in the ovary and fat body using RNAi led to a 15–63% increase in egg production with no adverse effects on egg viability during the first reproductive cycle. Knockdown of AaegPTEN3, expressed predominantly in the head, had no effect on reproduction. We also characterized the protein expression patterns of these two splice variants during development and in various tissues during a reproductive cycle. Conclusion Previous studies in a range of organisms, including Drosophila melanogaster and Caenorhabditis elegans, have demonstrated that disruption of the IIS cascade leads to decreased reproduction or sterility. In this study we demonstrate that knockdown of the IIS inhibitor PTEN can actually increase reproduction in the mosquito, at least during the first reproductive cycle.

  8. Bionomic response of Aedes aegypti to two future climate change scenarios in far north Queensland, Australia: implications for dengue outbreaks.

    Science.gov (United States)

    Williams, Craig R; Mincham, Gina; Ritchie, Scott A; Viennet, Elvina; Harley, David

    2014-09-19

    Dengue viruses are transmitted by anthropophilic mosquitoes and infect approximately 50 million humans annually. To investigate impacts of future climate change on dengue virus transmission, we investigated bionomics of the mosquito vector, Aedes aegypti. Using a dynamic life table simulation model (the Container inhabiting mosquito simulation CIMSiM) and statistically downscaled daily values for future climate, we assessed climate change induced changes to mosquito bionomics. Simulations of Ae. aegypti populations for current (1991-2011) and future climate (2046-2065) were conducted for the city of Cairns, Queensland, the population centre with most dengue virus transmission in Australia. Female mosquito abundance, wet weight, and the extrinsic incubation period for dengue virus in these mosquitoes were estimated for current and future climate (MPI ECHAM 5 model, B1 and A2 emission scenarios). Overall mosquito abundance is predicted to change, but results were equivocal for different climate change scenarios. Aedes aegypti abundance is predicted to increase under the B1, but decrease under the A2 scenario. Mosquitoes are predicted to have a smaller body mass in a future climate. Shorter extrinsic incubation periods are projected. It is therefore unclear whether dengue risk would increase or decrease in tropical Australia with climate change. Our findings challenge the prevailing view that a future, warmer climate will lead to larger mosquito populations and a definite increase in dengue transmission. Whilst general predictions can be made about future mosquito borne disease incidence, cautious interpretation is necessary due to interaction between local environment, human behaviour and built environment, dengue virus, and vectors.

  9. SOURCE REDUCTION BEHAVIOR AS AN INDEPENDENT MEASUREMENT OF THE IMPACT OF A PUBLIC HEALTH EDUCATION CAMPAIGN IN AN INTEGRATED VECTOR MANAGEMENT PROGRAM FOR THE ASIAN TIGER MOSQUITO

    Science.gov (United States)

    The goal of this study was to evaluate the effectiveness of a public health educational campaign to reduce backyard mosquito-larval habitats. Three communities each, within two New Jersey counties, were randomly selected to receive (1) both education and mosquito control, (2) education only, and (3)...

  10. Aedes aegypti uses RNA interference in defense against Sindbis virus infection

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    Wilusz Jeffrey

    2008-03-01

    Full Text Available Abstract Background RNA interference (RNAi is an important anti-viral defense mechanism. The Aedes aegypti genome encodes RNAi component orthologs, however, most populations of this mosquito are readily infected by, and subsequently transmit flaviviruses and alphaviruses. The goal of this study was to use Ae. aegypti as a model system to determine how the mosquito's anti-viral RNAi pathway interacts with recombinant Sindbis virus (SINV; family Togaviridae, genus Alphavirus. Results SINV (TR339-eGFP (+ strand RNA, infectious virus titers and infection rates transiently increased in mosquitoes following dsRNA injection to cognate Ago2, Dcr2, or TSN mRNAs. Detection of SINV RNA-derived small RNAs at 2 and 7 days post-infection in non-silenced mosquitoes provided important confirmation of RNAi pathway activity. Two different recombinant SINV viruses (MRE16-eGFP and TR339-eGFP with significant differences in infection kinetics were used to delineate vector/virus interactions in the midgut. We show virus-dependent effects on RNAi component transcript and protein levels during infection. Monitoring midgut Ago2, Dcr2, and TSN transcript levels during infection revealed that only TSN transcripts were significantly increased in midguts over blood-fed controls. Ago2 protein levels were depleted immediately following a non-infectious bloodmeal and varied during SINV infection in a virus-dependent manner. Conclusion We show that silencing RNAi components in Ae. aegypti results in transient increases in SINV replication. Furthermore, Ae. aegypti RNAi is active during SINV infection as indicated by production of virus-specific siRNAs. Lastly, the RNAi response varies in a virus-dependent manner. These data define important features of RNAi anti-viral defense in Ae. aegypti.

  11. Repellent activity of herbal essential oils against Aedes aegypti (Linn.) and Culex quinquefasciatus (Say.)

    OpenAIRE

    Duangkamon Sritabutra; Mayura Soonwera

    2013-01-01

    Objective: To determine the mosquito repellent activity of herbal essential oils against female Aedes aegypti and Culex quinquefasciatus. Methods: On a volunteer’s forearm, 0.1 mL of each essential oil was applied to 3 cm伊10 cm of exposed skin. The protection time was recorded for 3 min after every 30 min. Results: Essential oil from clove oil in olive oil and in coconut oil gave the longest lasting period of 76.50 min and 96.00 min respectively against Aedes aegypti. The citro...

  12. Field Evaluation of Indoor Thermal Fog and Ultra-Low Volume Applications For Control of Aedes aegypti in Thailand.

    Science.gov (United States)

    Ponlawat, A; Harwood, J F; Putnam, J L; Nitatsukprasert, C; Pongsiri, A; Kijchalao, U; Linthicum, K J; Kline, D L; Clark, G G; Obenauer, P J; Doud, C W; Mccardle, P W; Richardson, A G; Szumlas, D E; Richardson, J H

    2017-06-01

    Efficacies of a handheld thermal fogger (Patriot™) and a backpack ultra-low volume (ULV) sprayer (Twister™) with combinations of 2 different adulticides (pyrethrin, deltamethrin) and an insect growth regulator (pyriproxyfen) were field-tested and compared for their impact on reducing indoor Aedes aegypti populations in Thailand. The effectiveness of the indoor space sprays was evaluated by sampling the natural Ae. aegypti population in houses and determining their physiological status, by monitoring mortality of sentinel caged mosquitoes (AFRIMS strain) and by assessing larval mortality in laboratory bioassays using water exposed to the spray. A total of 14,742 Ae. aegypti were collected from Biogents Sentinel traps in this study. The combination of ULD® BP-300 (3% pyrethrin) and NyGuard® (10% pyriproxyfen) sprayed either by the Patriot or Twister significantly reduced some Ae. aegypti populations up to 20 days postspray relative to the control clusters. The addition of pyriproxyfen to the adulticide extended how long household mosquito populations were suppressed. In 2 of the 4 products being compared, the Twister resulted in higher mortality of caged mosquitoes compared with the Patriot. However, neither machine was able to achieve high mortality among Ae. aegypti placed in hidden (protected) cages. The larval bioassay results demonstrated that the Twister ULV provided better adult emergence inhibition than the Patriot (thermal fogger), likely due to larger droplet size.

  13. The elimination of the dengue vector, Aedes aegypti, from Brisbane, Australia: The role of surveillance, larval habitat removal and policy.

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    Brendan J Trewin

    2017-08-01

    Full Text Available Aedes aegypti (L. (Diptera: Culicidae is a highly invasive mosquito whose global distribution has fluctuated dramatically over the last 100 years. In Australia the distribution of Ae. aegypti once spanned the eastern seaboard, for 3,000 km north to south. However, during the 1900s this distribution markedly reduced and the mosquito disappeared from its southern range. Numerous hypotheses have been proffered for this retraction, however quantitative evidence of the mechanisms driving the disappearance are lacking. We examine historical records during the period when Ae. aegypti disappeared from Brisbane, the largest population centre in Queensland, Australia. In particular, we focus on the targeted management of Ae. aegypti by government authorities, that led to local elimination, something rarely observed in large cities. Numerous factors are likely to be responsible including the removal of larval habitat, especially domestic rainwater tanks, in combination with increased mosquito surveillance and regulatory enforcement. This account of historical events as they pertain to the elimination of Ae. aegypti from Brisbane, will inform assessments of the risks posed by recent human responses to climate change and the reintroduction of 300,000 rainwater tanks into the State over the past decade.

  14. Limited potential for transmission of live dengue virus vaccine candidates by Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Sardelis, M R; Edelman, R; Klein, T A; Innis, B L; Putnak, J R; Jones, J W; Turell, M J

    2000-06-01

    To evaluate the transmission risk of four live dengue (DEN) vaccine candidates developed by the U.S. Army (DEN-1, 45AZ5 PDK 20; DEN-2, S16803 PDK 50; DEN-3, CH53489 PDK 20; and DEN-4, 341750 PDK 20), we tested 3,010 Aedes aegypti and 1,576 Aedes albopictus mosquitoes blood-fed on 21 volunteers who had been administered one of the four vaccine candidates or the licensed yellow fever (YF) vaccine (17D). We used an indirect immunofluorescence assay (IFA) to detect DEN or YF viral antigen in the heads of mosquitoes. Corresponding to the lack of a detectable viremia among volunteers inoculated 8-13 days previously with live DEN-1 or DEN-2 vaccine candidates, only six mosquitoes developed disseminated infections after feeding on these volunteers. These six mosquitoes included 4 of 247 Ae. albopictus fed on volunteers inoculated with the DEN-1 vaccine candidate and 2 of 528 Ae. aegypti fed on volunteers inoculated with the DEN-2 vaccine candidate. Infection was confirmed in each of these IFA-positive mosquitoes by isolating infectious virus from the mosquito's body in Vero-cell culture. None of the 1,252 or the 969 mosquitoes fed on DEN-3 or DEN-4 recipients, respectively, were infected. Overall, dissemination rates in Ae. albopictus and Ae. aegypti were low. Dissemination rates were 0.5%, 0.3%, < 0.1%, and < 0.1% for the DEN-1 through DEN-4 vaccine candidates, respectively. Because of the observed low dissemination rates, it is unlikely that these vaccine viruses would be transmitted under natural conditions.

  15. Alterations in the Aedes aegypti transcriptome during infection with West Nile, dengue and yellow fever viruses.

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    Tonya M Colpitts

    2011-09-01

    Full Text Available West Nile (WNV, dengue (DENV and yellow fever (YFV viruses are (reemerging, mosquito-borne flaviviruses that cause human disease and mortality worldwide. Alterations in mosquito gene expression common and unique to individual flaviviral infections are poorly understood. Here, we present a microarray analysis of the Aedes aegypti transcriptome over time during infection with DENV, WNV or YFV. We identified 203 mosquito genes that were ≥ 5-fold differentially up-regulated (DUR and 202 genes that were ≥ 10-fold differentially down-regulated (DDR during infection with one of the three flaviviruses. Comparative analysis revealed that the expression profile of 20 DUR genes and 15 DDR genes was quite similar between the three flaviviruses on D1 of infection, indicating a potentially conserved transcriptomic signature of flaviviral infection. Bioinformatics analysis revealed changes in expression of genes from diverse cellular processes, including ion binding, transport, metabolic processes and peptidase activity. We also demonstrate that virally-regulated gene expression is tissue-specific. The overexpression of several virally down-regulated genes decreased WNV infection in mosquito cells and Aedes aegypti mosquitoes. Among these, a pupal cuticle protein was shown to bind WNV envelope protein, leading to inhibition of infection in vitro and the prevention of lethal WNV encephalitis in mice. This work provides an extensive list of targets for controlling flaviviral infection in mosquitoes that may also be used to develop broad preventative and therapeutic measures for multiple flaviviruses.

  16. [Dominance of Aedes aegypti over Aedes albopictus in the southeastern coast of Brazil].

    Science.gov (United States)

    Passos, Ricardo A; Marques, Gisela R A M; Voltolini, Júlio C; Condino, Maria Lúcia F

    2003-12-01

    To assess infestation of Aedes aegypti and Aedes albopiticus and describe their association with weather conditions and container colonization in urban areas. The town of São Sebastião in the southeastern coast of Brazil was selected. It was used data from the Dengue and Yellow Fever Vector Control Program of the State of S o Paulo, Brazil, that encompasses entomological surveillance at strategic positions, traps and foci demarcation. Strategic positions sites are fixed sites with containers in adequate conditions for larvae growth. Statistical analysis was performed using Kruskal-Wallis test, Dwass-Steel-Chritchlow-Fligne test and Mann-Whitney test. There was found an annual growth of positive traps and strategic positions of Ae. aegypti and a drop in Ae. albopictus population. An increase in immature Ae. aegypti and a drop of the other species were also seen. A gradual increase of positive dwellings for Ae. aegypti was noticed outgrowing Ae. albopictus population. There was a weak correlation of the Aedes species with abiotic factors. Higher numbers of immature mosquitoes of both species were found in artificial containers which could be eliminated. The study showed Ae. aegypti was predominant in urban areas, indicating that its growth seems to have affected the coexistence with other species. Natural selection could be in place contributing to Aedes aegypti and albopictus species separation.

  17. Laboratory evaluation of the response of Aedes aegypti and Aedes albopictus uninfected and infected with dengue virus to deet

    Science.gov (United States)

    Laboratory studies were conducted to compare the response of Aedes aegypti (L.) and Aedes albopictus (Skuse) adults, uninfected and infected with four serotypes of dengue virus, to a repellent containing 5% deet. The results showed that mosquitoes infected with the four serotypes of dengue respond i...

  18. Laboratory and semi-field evaluations of two (Transfluthrin) spatial repellent devices against Aedes aegypti (L.) (Diptera: Culicidae)

    Science.gov (United States)

    Two transfluthrin-based spatial repellent products (Raid Dual Action Insect Repellent and Home Freshener and Raid Shield (currently not commercially available), SC Johnson, Racine WI) were evaluated for spatial repellent effects against female Aedes aegypti (L.) mosquitoes underlaboratory (wind tunn...

  19. Behavioral responses of two dengue virus vectors, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), to DUET TM and its components

    Science.gov (United States)

    Ultralow volume (ULV) droplets of DUET TM, prallethrin and sumithrin at a sublethal dose were applied to unfed (non bloodfed) and bloodfed female Aedes aegypti Linn. and Aedes albopictus (Skuse) in a wind tunnel. Control spray droplets only contained inactive ingredients. Individual mosquitoes wer...

  20. The potential attractant or repellent effects of different water types on oviposition in Aedes aegypti L. (Dipt., Culicidae)

    NARCIS (Netherlands)

    Navarro, D.M.A.F.; Oliveira, de P.E.S.; Potting, R.P.J.; Brito, A.C.; Fital, S.J.F.; Goulart Sant Ana, A.E.

    2003-01-01

    The selection of oviposition sites by the yellow-fever mosquito, Aedes aegypti , was studied in the laboratory. The repellent or attractant effects of salinity and the presence of bacteria in water collected from a local community on the Brazilian coast were investigated. Water contaminated with

  1. Susceptibility of Aedes aegypti, Culex quinquefasciatus Say, and Anopheles quadrimaculatus Say to 19 Pesticides with Different Modes of Action

    Science.gov (United States)

    2008-01-01

    19 pesticides tested, Þpronil, a gamma amino butyric acid (GABA)-gated chloride channel antagonist, was the most toxic pesticide against Ae. aegypti...not currently registered for mosquito control, is a natural fermentation product of soil bacterium Strep- tomyces avermitilis. Because abamectin

  2. First detection of natural infection of Aedes aegypti with Zika virus in Brazil and throughout South America

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    Anielly Ferreira-de-Brito

    Full Text Available Zika virus (ZIKV has caused a major epidemic in Brazil and several other American countries. ZIKV is an arbovirus whose natural vectors during epidemics have been poorly determined. In this study, 1,683 mosquitoes collected in the vicinity of ZIKV suspected cases in Rio de Janeiro, Brazil, from June 2015 to May 2016 were screened for natural infection by using molecular methods. Three pools of Aedes aegypti were found with the ZIKV genome, one of which had only one male. This finding supports the occurrence of vertical and/or venereal transmission of ZIKV in Ae. aegypti in nature. None of the examined Ae. albopictus and Culex quinquefasciatus was positive. This is the first report of natural infection by ZIKV in mosquitoes in Brazil and other South American countries. So far, Ae. aegypti is the only confirmed vector of ZIKV during the ongoing Pan-American epidemics.

  3. Experimental investigation of the susceptibility of Italian Culex pipiens mosquitoes to Zika virus infection

    Science.gov (United States)

    Boccolini, Daniela; Toma, Luciano; Di Luca, Marco; Severini, Francesco; Romi, R; Remoli, Maria Elena; Sabbatucci, Michela; Venturi, Giulietta; Rezza, Giovanni; Fortuna, Claudia

    2016-01-01

    We investigated the susceptibility of an Italian population of Culex pipiens mosquitoes to Zika virus (ZIKV) infection, tested in parallel with Aedes aegypti, as a positive control. We analysed mosquitoes at 0, 3, 7, 10, 14, 20 and 24 days after an infectious blood meal. Viral RNA was detected in the body of Cx. pipiens up to three days post-infection, but not at later time points. Our results indicate that Cx. pipiens is not susceptible to ZIKV infection. PMID:27605056

  4. Toxicity Comparison of Eight Repellents Against Four Species of Female Mosquitoes

    Science.gov (United States)

    2009-01-01

    diseases such as yellow fever , dengue, and dengue hemorrhagic fever . These illnesses can cause severe human morbidity and mortality. The mosquito...446. Somboon P, Prapanthadara LA, Suwonkerd W. 2003. Insecticide susceptibility tests of Anopheles minimus s.l., Aedes aegypti, Aedes albopictus , and...evaluation of insect repellents as oviposition deterrents against the mosquito Aedes albopictus . Med Vet Entomol 15:126–131. Xue RD, Ali A, Barnard

  5. Preliminary findings on Bagaza virus (Flavivirus: Flaviviridae growth kinetics, transmission potential & transovarial transmission in three species of mosquitoes

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    A B Sudeep

    2013-01-01

    Full Text Available Background & objectives: Bagaza virus (BAGV, a flavivirus synonymous with Israel turkey meningoencephalitis virus, has been found to circulate in India. BAGV has recently been held responsible for inducing febrile illness in humans and causing unusually high mortality to wild birds in Spain. A study was therefore, undertaken to determine its replication kinetics in certain mosquitoes and to determine vector competence and potential of the mosquitoes to transmit BAGV experimentally. Methods: Aedes aegypti, Culex tritaeniorhynchus and Cx quinquefasciatus mosquitoes were inoculated with BAGV; samples were harvested every day and titrated in BHK-21 cell line. Vector competence and experimental transmission were determined by examining the saliva of infected mosquitoes for virus and induction of sickness in suckling mice, respectively. Results: Cx. tritaeniorhynchus and Ae. aegypti mosquitoes yielded 5 log 10 and 4.67 log 10 TCID 50 /ml of virus on day 3 post-infection (PI, respectively while Cx. quinquefasciatus yielded a titre of 4 log 10 TCID 50 /ml on day 4 PI. BAGV was detected in saliva of all the infected mosquitoes demonstrating their vector competence. Experimental transmission of BAGV to infant mice as well as transovarial transmission was demonstrated by Cx. tritaeniorhynchus but not by Ae. aegypti and Cx. quinquefasciatus mosquitoes. Interpretation & conclusions: Replication of BAGV to high titres and dissemination to saliva in three most prevalent mosquitoes in India is of immense public health importance. Though no major outbreak involving man has been reported yet, BAGV has a potential to cause outbreaks in future.

  6. Comparison of sampling techniques for Rift Valley Fever virus potential vectors, Aedes aegypti and Culex pipiens complex, in Ngorongoro District in northern Tanzania.

    Science.gov (United States)

    Mweya, Clement N; Kimera, Sharadhuli I; Karimuribo, Esron D; Mboera, Leonard E G

    2013-07-01

    We investigated mosquito sampling techniques with two types of traps and attractants at different time for trapping potential vectors for Rift Valley Fever virus. The study was conducted in six villages in Ngorongoro district in Tanzania from September to October 2012. A total of 1814 mosquitoes were collected, of which 738 were collected by CDC light traps and 1076 by Mosquito Magnet trapping technique. Of the collected mosquitoes, 12.46% (N = 226) were Aedes aegypti and 87.54% (N = 1588) were Culex pipiens complex. More mosquitoes were collected outdoors using Mosquito Magnets baited with octenol attractant, 36.38% (N =660) followed by indoor trapping using CDC light traps without attractant, 29.60% (N = 537). Most of Ae. aegypti mosquitoes were collected outdoor using Mosquito Magnets, 95% (N = 214) whereas Cx. pipiens complex were trapped both indoor using CDC light traps without attractant and outdoors using both CDC light traps baited with carbon dioxide (CO2) sachets and Mosquito Magnets. Analysis on the differences in abundance of mosquitoes trapped by different techniques using Generalized Linear Models was statistically significance at p-value < 0.05 for both species. Three hours mosquito collections show differing patterns in activity, most Ae. aegypti species were collected primarily during the first and last quarters of the day. Cx pipiens complex was active throughout the night, early evening and early morning then decreased markedly during the day time. The results presented in this paper emphasize the possibility of using Mosquito Magnets in order to efficiently capture these potential RVF vectors.

  7. Gene flow, subspecies composition, and dengue virus-2 susceptibility among Aedes aegypti collections in Senegal.

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    Massamba Sylla

    Full Text Available Aedes aegypti, the "yellow fever mosquito", is the primary vector to humans of the four serotypes of dengue viruses (DENV1-4 and yellow fever virus (YFV and is a known vector of Chikungunya virus. There are two recognized subspecies of Ae. aegypti sensu latu (s.l.: the presumed ancestral form, Ae. aegypti formosus (Aaf, a primarily sylvan mosquito in sub-Saharan Africa, and Ae. aegypti aegypti (Aaa, found globally in tropical and subtropical regions typically in association with humans. The designation of Ae. aegypti s.l. subspecies arose from observations made in East Africa in the late 1950s that the frequency of pale "forms" of Ae. aegypti was higher in populations in and around human dwellings than in those of the nearby bush. But few studies have been made of Ae. aegypti s.l. in West Africa. To address this deficiency we have been studying the population genetics, subspecies composition and vector competence for DENV-2 of Ae. aegypti s.l. in Senegal.A population genetic analysis of gene flow was conducted among 1,040 Aedes aegypti s.l. from 19 collections distributed across the five phytogeographic regions of Senegal. Adults lacking pale scales on their first abdominal tergite were classified as Aedes aegypti formosus (Aaf following the original description of the subspecies and the remainder were classified as Aedes aegypti aegypti (Aaa. There was a clear northwest-southeast cline in the abundance of Aaa and Aaf. Collections from the northern Sahelian region contained only Aaa while southern Forest gallery collections contained only Aaf. The two subspecies occurred in sympatry in four collections north of the Gambia in the central Savannah region and Aaa was a minor component of two collections from the Forest gallery area. Mosquitoes from 11 collections were orally challenged with DENV-2 virus. In agreement with the early literature, Aaf had significantly lower vector competence than Aaa. Among pure Aaa collections, the disseminated

  8. Plan Continental de ampliación e intensificación del combate a Aedes aegypti

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    1998-01-01

    Full Text Available Campaigns for the eradication of Aedes aegypti, the mosquito vector responsible for spreading dengue and yellow fever, enjoyed great success during the forties and fifties. Between 1948 and 1962, A. aegypti disappeared from 21 countries in the Region of the Americas, but lack of sustainability of the programs resulted in the gradual reinfestation of practically all countries. In an effort to combat the situation, in 1995 PAHO began to help its Member States with the creation of an expert panel charged with drawing up a continental plan of action for eradicating A. aegypti from all countries. The Continental Plan for expanding and intensifying the war against Aedes aegypti was drawn up in Caracas, Venezuela, in April of 1997, in accordance with the objectives previously established by the countries. The plan's success will depend on having all countries commit themselves to putting it into effect and to providing the national funds that are needed for its full implementation.

  9. wMel limits zika and chikungunya virus infection in a Singapore Wolbachia-introgressed Ae. aegypti strain, wMel-Sg.

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    Cheong Huat Tan

    2017-05-01

    Full Text Available Zika (ZIKV and Chikungunya (CHIKV viruses are emerging Aedes-borne viruses that are spreading outside their known geographic range and causing wide-scale epidemics. It has been reported that these viruses can be transmitted efficiently by Ae. aegypti. Recent studies have shown that Ae. aegypti when transinfected with certain Wolbachia strains shows a reduced replication and dissemination of dengue (DENV, Chikungunya (CHIKV, and Yellow Fever (YFV viruses. The aim of this study was to determine whether the wMel strain of Wolbachia introgressed onto a Singapore Ae. aegypti genetic background was able to limit ZIKV and CHIKV infection in the mosquito.Five to seven-day old mosquitoes either infected or uninfected with wMel Wolbachia were orally infected with a Ugandan strain of ZIKV and several outbreak strains of CHIKV. The midgut and salivary glands of each mosquito were sampled at days 6, 9 and 13 days post infectious blood meal to determine midgut infection and salivary glands dissemination rates, respectively. In general, all wild type Ae. aegypti were found to have high ZIKV and CHIKV infections in their midguts and salivary glands, across all sampling days, compared to Wolbachia infected counterparts. Median viral titre for all viruses in Wolbachia infected mosquitoes were significantly lower across all time points when compared to wild type mosquitoes. Most significantly, all but two and one of the wMel infected mosquitoes had no detectable ZIKV and CHIKV, respectively, in their salivary glands at 14 days post-infectious blood meal.Our results showed that wMel limits both ZIKV and CHIKV infection when introgressed into a Singapore Ae. aegypti genetic background. These results also strongly suggest that female Aedes aegypti carrying Wolbachia will have a reduced capacity to transmit ZIKV and CHIKV.

  10. PENGARUH SERAI WANGI TERHADAP KEBERADAAN LARVA AEDES AEGYPTI PADA TEMPAT PENAMPUNGAN AIR

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    Rustam Aji

    2017-01-01

    Full Text Available Abstract: The Effect of Citronella with the presence of Aedes Aegypti Larvae in Water Reservoir. Citronella, a plant that was encountered areas, it can be used as food seasonings, and it can also be used as a repellent even natural killer mosquito larvae and it does not have serious consequences for human health. The design of this study is using a quasi-experimental study with a sample of 80 respondents. Techniques of data collection were done by a survey of residents who plant citronella. The results showed that 62.5% of the people who plant citronella in the yard of their home, 77.5% of them are not found larvae of Aedes aegypti in the water reservoirs. The statistical results showed that there is a significant effect of Citronella with the presence of Aedes aegypti larvae in water reservoirs environment where OR = 4,375. Suggestions for people to cultivate the plant of citronella near water reservoirs in an attempt deterrent presence of Aedes aegypti larvae. Abstrak: Pengaruh Serai Wangi Terhadap Keberadaan Larva Aedes Aegypti Pada Tempat Penampungan Air. Tanaman serai wangi adalah suatu  tumbuhan yang banyak ditemui di daerah. Serai wangi bisa dimanfaatkan sebagai bumbu penyedap masakan, dan dapat juga digunakan sebagai pengusir bahkan pembunuh jentik nyamuk secara alamiah dan tidak berdampak serius bagi kesehatan manusia. Rancangan penelitian ini dengan menggunakan metode kuasi eksperimen dengan sampel penelitian 80 responden. Teknik pengumpulan data dilakukan dengan cara survei terhadap warga yang menanam serai wangi. Hasil penelitian menunjukkan bahwa dari 62,5 % warga yang menanam serai wangi di pekarangan rumah, 77,5% diantaranya tidak ditemukan jentik Aedes aegypti di lingkungan tempat penampungan air. Hasil statistik menunjukkan adanya pengaruh yang signifikan antara tanaman serai wangi dengan keberadaan jentik  Aedes aegypti pada lingkungan tempat penampungan air dimana OR= 4.375. Saran agar masyarakat dapat membudidayakan tanaman

  11. A survey of bacterial, fungal and plant metabolites against Aedes aegypti (Diptera: Culicidae, the vector of yellow and dengue fevers and Zika virus

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    Masi Marco

    2017-06-01

    Full Text Available Aedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. Some bacterial, fungal and plant metabolites belonging to different chemical subgroups, including Amaryllidaceae alkaloids, anthracenes, azoxymethoxytetrahydropyrans, cytochalasans, 2,5-diketopiperazines, isochromanones, naphthoquinones, organic small acids and their methyl esters, sterols and terpenes including sesquiterpenes and diterpenes, were tested for their larvicidal and adulticidal activity against Ae. aegypti. Out of 23 compounds tested, gliotoxin exhibited mosquitocidal activity in both bioassays with an LC50 value of 0.0257 ± 0.001 µg/µL against 1st instar Ae. aegypti and LD50 value of 2.79 ± 0.1197 µg/mosquito against adult female Ae. aegypti. 2-Methoxy-1,4-naphthoquinone and cytochalasin A showed LC50 values of 0.0851 ± 0.0012 µg/µL and 0.0854 ± 0.0019 µg/µL, respectively, against Ae. aegypti larvae. In adult bioassays, fusaric acid (LD50= 0.8349 ± 0.0118 µg/mosquito, 3-nitropropionic acid (LD50 = 1.6641 ± 0.0494 µg/mosquito and α-costic acid (LD50 = 2.547 ± 0.0835 µg/mosquito exhibited adulticidal activity. Results from the current study confirm that compounds belonging to cytochalsin, diketopiperazine, naphthoquinone and low molecular weight organic acid groups are active and may stimulate further SAR investigations.

  12. Reciprocal tripartite interactions between the Aedes aegypti midgut microbiota, innate immune system and dengue virus influences vector competence.

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    Jose Luis Ramirez

    Full Text Available Dengue virus is one of the most important arboviral pathogens and the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It is transmitted between humans by the mosquitoes Aedes aegypti and Aedes albopictus, and at least 2.5 billion people are at daily risk of infection. During their lifecycle, mosquitoes are exposed to a variety of microbes, some of which are needed for their successful development into adulthood. However, recent studies have suggested that the adult mosquito's midgut microflora is critical in influencing the transmission of human pathogens. In this study we assessed the reciprocal interactions between the mosquito's midgut microbiota and dengue virus infection that are, to a large extent, mediated by the mosquito's innate immune system. We observed a marked decrease in susceptibility to dengue virus infection when mosquitoes harbored certain field-derived bacterial isolates in their midgut. Transcript abundance analysis of selected antimicrobial peptide genes suggested that the mosquito's microbiota elicits a basal immune activity that appears to act against dengue virus infection. Conversely, the elicitation of the mosquito immune response by dengue virus infection itself influences the microbial load of the mosquito midgut. In sum, we show that the mosquito's microbiota influences dengue virus infection of the mosquito, which in turn activates its antibacterial responses.

  13. Reciprocal Tripartite Interactions between the Aedes aegypti Midgut Microbiota, Innate Immune System and Dengue Virus Influences Vector Competence

    Science.gov (United States)

    Ramirez, Jose Luis; Souza-Neto, Jayme; Torres Cosme, Rolando; Rovira, Jose; Ortiz, Alma; Pascale, Juan M.; Dimopoulos, George

    2012-01-01

    Dengue virus is one of the most important arboviral pathogens and the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It is transmitted between humans by the mosquitoes Aedes aegypti and Aedes albopictus, and at least 2.5 billion people are at daily risk of infection. During their lifecycle, mosquitoes are exposed to a variety of microbes, some of which are needed for their successful development into adulthood. However, recent studies have suggested that the adult mosquito's midgut microflora is critical in influencing the transmission of human pathogens. In this study we assessed the reciprocal interactions between the mosquito's midgut microbiota and dengue virus infection that are, to a large extent, mediated by the mosquito's innate immune system. We observed a marked decrease in susceptibility to dengue virus infection when mosquitoes harbored certain field-derived bacterial isolates in their midgut. Transcript abundance analysis of selected antimicrobial peptide genes suggested that the mosquito's microbiota elicits a basal immune activity that appears to act against dengue virus infection. Conversely, the elicitation of the mosquito immune response by dengue virus infection itself influences the microbial load of the mosquito midgut. In sum, we show that the mosquito's microbiota influences dengue virus infection of the mosquito, which in turn activates its antibacterial responses. PMID:22413032

  14. AN IMPROVED TRAP TO CAPTURE ADULT CONTAINER-INHABITING MOSQUITOES

    Science.gov (United States)

    BARRERA, ROBERTO; MACKAY, ANDREW J.; AMADOR, MANUEL

    2015-01-01

    Although dengue viruses are thought to be transmitted by Aedes aegypti in Puerto Rico, Aedes mediovittatus, the Caribbean tree hole mosquito, is also a potential vector. This species is native to the Greater Antilles and has been shown to be a competent vector of dengue viruses in the laboratory. Consequently, it has been suggested that Ae. mediovittatus could be acting as a secondary vector or virus reservoir. This study was part of an ongoing investigation into this, and it aimed to determine whether BG-Sentinel traps (BGS traps) could be used to collect adults of this mosquito and could be modified to increase the number of captures of this species in the field. We conducted experiments to test the relative attractiveness of BGS traps to Ae. mediovittatus and Ae. aegypti and explored the effects of chemical lures (BG-Lure, CO2, octenol) and optical properties (color, size) on the capture rates of BGS traps in a large, outdoor cage in San Juan city, Puerto Rico. We also conducted field tests to compare modified BGS traps with the original traps in a rural community in Patillas municipality, Puerto Rico. Results obtained from the large, outdoor cage experiments indicated that trap captures of both mosquito species could be significantly enhanced by using black instead of white BGS traps combined with BG-Lure. Field experiments revealed that the modified traps captured a significantly greater number of Ae. aegypti, Ae. mediovittatus, and Culex quinquefasciatus, with greater sensitivity for the latter 2 species, and also captured a larger number of mosquito species and a smaller ratio of Ae. aegypti to Ae. mediovittatus, with greater than expected species co-occurrences. PMID:24551969

  15. Repellents inhibit P450 enzymes in Stegomyia (Aedes aegypti.

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    Gloria Isabel Jaramillo Ramirez

    Full Text Available The primary defence against mosquitoes and other disease vectors is often the application of a repellent. Despite their common use, the mechanism(s underlying the activity of repellents is not fully understood, with even the mode of action of DEET having been reported to be via different mechanisms; e.g. interference with olfactory receptor neurones or actively detected by olfactory receptor neurones on the antennae or maxillary palps. In this study, we discuss a novel mechanism for repellence, one of P450 inhibition. Thirteen essential oil extracts from Colombian plants were assayed for potency as P450 inhibitors, using a kinetic fluorometric assay, and for repellency using a modified World Health Organisation Pesticide Evaluations Scheme (WHOPES arm-in cage assay with Stegomyia (Aedes aegypti mosquitoes. Bootstrap analysis on the inhibition analysis revealed a significant correlation between P450-inhibition and repellent activity of the oils.

  16. Effects of insemination and blood-feeding on locomotor activity of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) females under laboratory conditions.

    Science.gov (United States)

    Lima-Camara, Tamara Nunes; Lima, José Bento Pereira; Bruno, Rafaela Vieira; Peixoto, Alexandre Afranio

    2014-07-02

    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.

  17. Updated Reported Distribution of Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera: Culicidae) in the United States, 1995-2016.

    Science.gov (United States)

    Hahn, Micah B; Eisen, Lars; McAllister, Janet; Savage, Harry M; Mutebi, John-Paul; Eisen, Rebecca J

    2017-09-01

    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.

  18. Dengue virus type 3 isolation from Aedes aegypti in the municipality of Nova Iguaçu, State of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Ricardo Lourenço-de-Oliveira

    2002-09-01

    Full Text Available In a prospective field study conducted from July 2000 to June 2001, adult Aedes aegypti and Ae. albopictus mosquitoes were caught from the municipality of Nova Iguaçu, State of Rio de Janeiro, Brazil. Virus isolation in Ae. albopictus clone C6/36 cell line and a semi-nested reverse transcription-polymerase chain reaction detected only dengue virus type 3 in three pools of Ae. aegypti, despite the co-circulation of DEN-1, DEN-2 and DEN-3 serotypes in that area. No viruses were detected in Ae. albopictus mosquitoes. This virological surveillance consists in a sentinel system alerting for dengue outbreaks.

  19. Mosquito, egg raft (image)

    Science.gov (United States)

    Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in still or stagnant water. The mosquito ... mosquitoes. (Image courtesy of the Centers for Disease Control and Prevention.)

  20. PEMANFAATAN KULIT BUAH JERUK NIPIS (Citrus aurantifolia SEBAGAI LARVASIDA Aedes aegypti INSTAR III

    Directory of Open Access Journals (Sweden)

    evy Ratnasari Ekawati

    2017-01-01

    Full Text Available DHF (Dengue disease is transmitted through mosquito vectorAedes aegypti.One way to do control the Dengue vector is to use insecticide made from natural materials and is environmentally friendly with lemon peel extract (Citrusaurantifolia. This study aims to determine the effectiveness of extracts of lemon peel (Citrus aurantifolia in killing the third instar larvae Aedesaegypti with various concentrations and time variations. This were an experimental laboratory researchs using various concentrations of extract limes peel (Citrusaurantifolia 1%, 2%, 3%, 4%, 5%, 6%, and 7% in which there 25 larvae Aedes aegypti and using a variation of 30, 60, 90, 120, 180, 240, 300, and 1440 minutes after contact with the extracts limes peel (Citrusaurantifolia. Effective concentration to kill larvae of Aedes aegypti by 50% (IC50 was the concentration of 3.419%.