WorldWideScience

Sample records for aegypti mosquito reduction

  1. Dispersal of Engineered Male Aedes aegypti Mosquitoes

    OpenAIRE

    Peter Winskill; Carvalho, Danilo O.; Capurro, Margareth L.; Luke Alphey; Donnelly, Christl A.; McKemey, Andrew R.

    2015-01-01

    Background Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of ‘genetically sterile’ male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed. Methodology/Principal Findings The dispersal ability of released ‘genetically sterile’ male Aedes aegypti at a field ...

  2. Dispersal of Engineered Male Aedes aegypti Mosquitoes.

    OpenAIRE

    Peter Winskill; Carvalho, Danilo O.; Capurro, Margareth L.; Luke Alphey; Donnelly, Christl A.; McKemey, Andrew R.

    2015-01-01

    Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of 'genetically sterile' male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed.The dispersal ability of released 'genetically sterile' male Aedes aegypti at a field site in Brazil has been estimated. Dispersa...

  3. Free flight of the mosquito Aedes aegypti

    CERN Document Server

    Iams, S M

    2012-01-01

    High speed video observations of free flying male Aedes aegypti mosquitoes, the dengue and yellow fever vector, along with custom measurement methods, enable measurement of wingbeat frequency, body position and body orientation of mosquitoes during flight. We find these mosquitoes flap their wings at approximately 850 Hz. We also generate body yaw, body pitch and wing deviation measurements with standard deviations of less than 1 degree and find that sideways velocity and acceleration are important components of mosquito motion. Rapid turns involving changes in flight direction often involve large sideways accelerations. These do not correspond to commensurate changes in body heading, and the insect's flight direction and body heading are decoupled during flight. These findings call in to question the role of yaw control in mosquito flight. In addition, using orientation data, we find that sideways accelerations are well explained by roll-based rotation of the lift vector. In contrast, the insect's body pitch...

  4. Dispersal of Engineered Male Aedes aegypti Mosquitoes.

    Directory of Open Access Journals (Sweden)

    Peter Winskill

    2015-11-01

    Full Text Available Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of 'genetically sterile' male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed.The dispersal ability of released 'genetically sterile' male Aedes aegypti at a field site in Brazil has been estimated. Dispersal kernels embedded within a generalized linear model framework were used to analyse data collected from three large scale mark release recapture studies. The methodology has been applied to previously published dispersal data to compare the dispersal ability of 'genetically sterile' male Aedes aegypti in contrasting environments. We parameterised dispersal kernels and estimated the mean distance travelled for insects in Brazil: 52.8 m (95% CI: 49.9 m, 56.8 m and Malaysia: 58.0 m (95% CI: 51.1 m, 71.0 m.Our results provide specific, detailed estimates of the dispersal characteristics of released 'genetically sterile' male Aedes aegypti in the field. The comparative analysis indicates that despite differing environments and recapture rates, key features of the insects' dispersal kernels are conserved across the two studies. The results can be used to inform both risk assessments and release programmes using 'genetically sterile' male Aedes aegypti.

  5. Genome engineering and gene drive in the mosquito aedes aegypti

    OpenAIRE

    St John, Oliver Tudor Lockhart; Sinkins, Steven; Alphey, Luke

    2012-01-01

    Genetic control strategies are a novel method for reducing populations of pest insects such as the yellow fever mosquito Aedes aegypti, a major vector of several important arboviral diseases. This thesis describes efforts to develop new tools to engineer the Ae. aegypti genome and to better understand existing tools, and furthermore to use these to engineer a gene drive system in Ae. aegypti. The piggyBac transposon was found to be extremely stable in the germline of Ae. aegypti, and transpos...

  6. Multiple QTL Determine Dorsal Abdominal Scale Patterns in the Mosquito Aedes aegypti.

    Science.gov (United States)

    Mori, Akio; Tsuda, Yoshio; Takagi, Masahiro; Higa, Yukiko; Severson, David W

    2016-09-01

    The mosquito, Aedes aegypti (L.) originated in Sub-Saharan Africa as a dark form sylvan species (A. aegypti formosus). Evolution of A. aegypti aegypti type form as a human commensal facilitated its colonization of most semitropical and tropical areas. We investigated the genetic basis for abdominal white scale presence that represents the diagnostic for sylvan A. aegypti formosus (scales absent), from type form (scales present) and A. aegypti queenslandensis form (dense scaling). We performed quantitative trait locus (QTL) mapping using 3 criteria for scale patterns among 192 F1 intercross progeny from matings between a queenslandensis type and an aegypti type form. Results identified 3 QTL determining scale patterns and indicated that classification criteria impact robustness of QTL LOD support. Dark- and light-colored forms exist in sympatry, but vary in multiple phenotypic characteristics, including preferences for vertebrate host, oviposition container, house-entering behavior, and dengue vector competence. Markers associated with 2 QTL regions reflected major reductions in recombination frequencies compared with the standard type form linkage map, suggestive of inversion polymorphisms associated with observed linkage disequilibrium between type-specific characteristics. Understanding the genic basis for differences in A. aegypti forms could inform efforts to develop new mosquito and arboviral disease control strategies. PMID:27130203

  7. Oviposition and olfaction responses of Aedes aegypti mosquitoes to insecticides.

    Science.gov (United States)

    Canyon, D V; Muller, R

    2013-12-01

    Insecticide applications are not particularly effective on Aedes aegypti mosquitoes which has been attributed to their 'closet' behaviour, or ability to rest in places that remain unexposed to insecticides. Some researchers have suggested that insecticides repel mosquitoes, which would result in less exposure and increased dispersal. If repellence due to insecticides is a fact, acquiring a vector-borne disease, such as dengue, could legitimately be attributed to local vector control efforts and this would lead to restitution claims. This study thus investigated the effect of insecticide presence on mosquito behaviour indirectly via oviposition and directly via olfactory response. In all experiments, oviposition in each insecticide compared to its water and ethanol controls was not significantly different. This indicates that Ae. aegypti mosquitoes are not affected by insecticide presence and that increased dispersal is unlikely to be caused by vector control spraying.

  8. Experience- and age-mediated oviposition behaviour in the yellow fever mosquito Stegomyia aegypti (=Aedes aegypti).

    Science.gov (United States)

    Ruktanonchai, N W; Lounibos, L P; Smith, D L; Allan, S A

    2015-09-01

    In repeated behaviours such as those of feeding and reproduction, past experiences can inform future behaviour. By altering their behaviour in response to environmental stimuli, insects in highly variable landscapes can tailor their behaviour to their particular environment. In particular, female mosquitoes may benefit from plasticity in their choice of egg-laying site as these sites are often temporally variable and clustered. The opportunity to adapt egg-laying behaviour to past experience also exists for mosquito populations as females typically lay eggs multiple times throughout their lives. Whether experience and age affect egg-laying (or oviposition) behaviour in the mosquito Stegomyia aegypti (=Aedes aegypti) (Diptera: Culicidae) was assessed using a wind tunnel. Initially, gravid mosquitoes were provided with a cup containing either repellent or well water. After ovipositing in these cups, the mosquitoes were blood-fed and introduced into a wind tunnel. In this wind tunnel, an oviposition cup containing repellent was placed in the immediate vicinity of the gravid mosquitoes. A cup containing well water was placed at the opposite end of the tunnel so that if the females flew across the chamber, they encountered the well water cup, in which they readily laid eggs. Mosquitoes previously exposed to repellent cups became significantly more likely to later lay eggs in repellent cups, suggesting that previous experience with suboptimal oviposition sites informs mosquitoes of the characteristics of nearby oviposition sites. These results provide further evidence that mosquitoes modify behaviour in response to environmental information and are demonstrated in a vector species in which behavioural plasticity may be ecologically and epidemiologically meaningful. PMID:25982411

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

    OpenAIRE

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

    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...

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

    Directory of Open Access Journals (Sweden)

    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

  11. QTL Mapping of Genome Regions Controlling Temephos Resistance in Larvae of the Mosquito Aedes aegypti

    OpenAIRE

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

    2014-01-01

    Introduction 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. Methodology/Principal Findings 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 s...

  12. Genome-engineering with CRISPR-Cas9 in the mosquito Aedes aegypti

    OpenAIRE

    Kathryn E. Kistler; Leslie B. Vosshall; Benjamin J. Matthews

    2015-01-01

    The mosquito Aedes aegypti is a potent vector of the chikungunya, yellow fever, and dengue viruses, responsible for hundreds of millions of infections and over 50,000 human deaths per year. Mutagenesis in Ae. aegypti has been established with TALENs, ZFNs, and homing endonucleases, which require the engineering of DNA-binding protein domains to provide genomic target sequence specificity. Here, we describe the use of the CRISPR-Cas9 system to generate site-specific mutations in Ae. aegypti. T...

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

    OpenAIRE

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

    2014-01-01

    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 ...

  14. Molecular identification of Aedes aegypti mosquitoes from Pilani region of Rajasthan, India

    OpenAIRE

    Kuldeep Gupta; Rini Dhawan; Mithilesh Kajla; Sanjeev Kumar; B Jnanasiddhy; Singh, Naveen K.; Rajnikant Dixit; Ashish Bihani; Lalita Gupta

    2016-01-01

    Background & objectives: Aedes aegypti is the most important vector of dengue virus infection in humans worldwide. Accurate identification and colonization are the essential requirements to understand vector biology as well as its diseases transmission potential. In this study, we have used molecular approaches for the identification of Ae. aegypti mosquitoes that were collected from the Pilani region of Rajasthan, India Methods: Field collected mosquito larvae were colonized under laborat...

  15. Wolbachia-associated bacterial protection in the mosquito Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Yixin H Ye

    Full Text Available BACKGROUND: Wolbachia infections confer protection for their insect hosts against a range of pathogens including bacteria, viruses, nematodes and the malaria parasite. A single mechanism that might explain this broad-based pathogen protection is immune priming, in which the presence of the symbiont upregulates the basal immune response, preparing the insect to defend against subsequent pathogen infection. A study that compared natural Wolbachia infections in Drosophila melanogaster with the mosquito vector Aedes aegypti artificially transinfected with the same strains has suggested that innate immune priming may only occur in recent host-Wolbachia associations. This same study also revealed that while immune priming may play a role in viral protection it cannot explain the entirety of the effect. METHODOLOGY/FINDINGS: Here we assess whether the level of innate immune priming induced by different Wolbachia strains in A. aegypti is correlated with the degree of protection conferred against bacterial pathogens. We show that Wolbachia strains wMel and wMelPop, currently being tested for field release for dengue biocontrol, differ in their protective abilities. The wMelPop strain provides stronger, more broad-based protection than wMel, and this is likely explained by both the higher induction of immune gene expression and the strain-specific activation of particular genes. We also show that Wolbachia densities themselves decline during pathogen infection, likely as a result of the immune induction. CONCLUSIONS/SIGNIFICANCE: This work shows a correlation between innate immune priming and bacterial protection phenotypes. The ability of the Toll pathway, melanisation and antimicrobial peptides to enhance viral protection or to provide the basis of malaria protection should be further explored in the context of this two-strain comparison. This work raises the questions of whether Wolbachia may improve the ability of wild mosquitoes to survive pathogen

  16. Intriguing olfactory proteins from the yellow fever mosquito, Aedes aegypti

    Science.gov (United States)

    Ishida, Yuko; Chen, Angela M.; Tsuruda, Jennifer M.; Cornel, Anthon J.; Debboun, Mustapha; Leal, Walter S.

    2004-09-01

    Four antennae-specific proteins (AaegOBP1, AaegOBP2, AaegOBP3, and AaegASP1) were isolated from the yellow fever mosquito, Aedes aegypti and their full-length cDNAs were cloned. RT-PCR indicated that they are expressed in female and, to a lesser extent, in male antennae, but not in control tissues (legs). AaegOBP1 and AaegOBP3 showed significant similarity to previously identified mosquito odorant-binding proteins (OBPs) in cysteine spacing pattern and sequence. Two of the isolated proteins have a total of eight cysteine residues. The similarity of the spacing pattern of the cysteine residues and amino acid sequence to those of previously identified olfactory proteins suggests that one of the cysteine-rich proteins (AaegOBP2) is an OBP. The other (AaegASP1) did not belong to any group of known OBPs. Structural analyses indicate that six of the cysteine residues in AaegOBP2 are linked in a similar pattern to the previously known cysteine pairing in OBPs, i.e., Cys-24 Cys-55, Cys-51 Cys-104, Cys-95 Cys-113. The additional disulfide bridge, Cys-38 Cys-125, knits the extended C-terminal segment of the protein to a predicted α2-helix. As indicated by circular dichroism (CD) spectra, the extra rigidity seems to prevent the predicted formation of a C-terminal α-helix at low pH.

  17. Inhibition of luciferase expression in transgenic Aedes aegypti mosquitoes by Sindbis virus expression of antisense luciferase RNA.

    Science.gov (United States)

    Johnson, B W; Olson, K E; Allen-Miura, T; Rayms-Keller, A; Carlson, J O; Coates, C J; Jasinskiene, N; James, A A; Beaty, B J; Higgs, S

    1999-11-01

    A rapid and reproducible method of inhibiting the expression of specific genes in mosquitoes should further our understanding of gene function and may lead to the identification of mosquito genes that determine vector competence or are involved in pathogen transmission. We hypothesized that the virus expression system based on the mosquito-borne Alphavirus, Sindbis (Togaviridae), may efficiently transcribe effector RNAs that inhibit expression of a targeted mosquito gene. To test this hypothesis, germ-line-transformed Aedes aegypti that express luciferase (LUC) from the mosquito Apyrase promoter were intrathoracically inoculated with a double subgenomic Sindbis (dsSIN) virus TE/3'2J/anti-luc (Anti-luc) that transcribes RNA complementary to the 5' end of the LUC mRNA. LUC activity was monitored in mosquitoes infected with either Anti-luc or control dsSIN viruses expressing unrelated antisense RNAs. Mosquitoes infected with Anti-luc virus exhibited 90% reduction in LUC compared with uninfected and control dsSIN-infected mosquitoes at 5 and 9 days postinoculation. We demonstrate that a gene expressed from the mosquito genome can be inhibited by using an antisense strategy. The dsSIN antisense RNA expression system is an important tool for studying gene function in vivo. PMID:10557332

  18. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Adult survivorship of the dengue mosquito Aedes aegypti varies seasonally in central Vietnam.

    Directory of Open Access Journals (Sweden)

    Leon E Hugo

    2014-02-01

    Full Text Available The survival characteristics of the mosquito Aedes aegypti affect transmission rates of dengue because transmission requires infected mosquitoes to survive long enough for the virus to infect the salivary glands. Mosquito survival is assumed to be high in tropical, dengue endemic, countries like Vietnam. However, the survival rates of wild populations of mosquitoes are seldom measured due the difficulty of predicting mosquito age. Hon Mieu Island in central Vietnam is the site of a pilot release of Ae. aegypti infected with a strain of Wolbachia pipientis bacteria (wMelPop that induces virus interference and mosquito life-shortening. We used the most accurate mosquito age grading approach, transcriptional profiling, to establish the survival patterns of the mosquito population from the population age structure. Furthermore, estimations were validated on mosquitoes released into a large semi-field environment consisting of an enclosed house, garden and yard to incorporate natural environmental variability. Mosquito survival was highest during the dry/cool (January-April and dry/hot (May-August seasons, when 92 and 64% of Hon Mieu mosquitoes had survived to an age that they were able to transmit dengue (12 d, respectively. This was reduced to 29% during the wet/cool season from September to December. The presence of Ae. aegypti older than 12 d during each season is likely to facilitate the observed continuity of dengue transmission in the region. We provide season specific Ae. aegypti survival models for improved dengue epidemiology and evaluation of mosquito control strategies that aim to reduce mosquito survival to break the dengue transmission cycle.

  1. Suppression of RNA interference increases alphavirus replication and virus-associated mortality in Aedes aegypti mosquitoes

    Directory of Open Access Journals (Sweden)

    Geiss Brian J

    2009-03-01

    Full Text Available Abstract Background Arthropod-borne viruses (arboviruses can persistently infect and cause limited damage to mosquito vectors. RNA interference (RNAi is a mosquito antiviral response important in restricting RNA virus replication and has been shown to be active against some arboviruses. The goal of this study was to use a recombinant Sindbis virus (SINV; family Togaviridae; genus Alphavirus that expresses B2 protein of Flock House virus (FHV; family Nodaviridae; genus Alphanodavirus, a protein that inhibits RNAi, to determine the effects of linking arbovirus infection with RNAi inhibition. Results B2 protein expression from SINV (TE/3'2J inhibited the accumulation of non-specific small RNAs in Aedes aegypti mosquito cell culture and virus-specific small RNAs both in infected cell culture and Ae. aegypti mosquitoes. More viral genomic and subgenomic RNA accumulated in cells and mosquitoes infected with TE/3'2J virus expressing B2 (TE/3'2J/B2 compared to TE/3'2J and TE/3'2J virus expressing GFP. TE/3'2J/B2 exhibited increased infection rates, dissemination rates, and infectious virus titers in mosquitoes following oral bloodmeal. Following infectious oral bloodmeal, significantly more mosquitoes died when TE/3'2J/B2 was ingested. The virus was 100% lethal following intrathoracic inoculation of multiple mosquito species and lethality was dose-dependent in Ae. aegypti. Conclusion We show that RNAi is active in Ae. aegypti cell culture and that B2 protein inhibits RNAi in mosquito cells when expressed by a recombinant SINV. Also, SINV more efficiently replicates in mosquito cells when RNAi is inhibited. Finally, TE/3'2J/B2 kills mosquitoes in a dose-dependent manner independent of infection route and mosquito species.

  2. Multiple factors contribute to anautogenous reproduction by the mosquito Aedes aegypti.

    Science.gov (United States)

    Gulia-Nuss, Monika; Elliot, Anne; Brown, Mark R; Strand, Michael R

    2015-11-01

    Aedes aegypti is an anautogenous mosquito that must blood feed on a vertebrate host to produce and lay a clutch of eggs. The rockpool mosquito, Georgecraigius atropalpus, is related to A. aegypti but is a facultatively autogenous species that produces its first clutch of eggs shortly after emerging without blood feeding. Consumption of a blood meal by A. aegypti triggers the release of ovary ecdysteroidogenic hormone (OEH) and insulin-like peptide 3 (ILP3) from the brain, which stimulate egg formation. OEH and ILP3 also stimulate egg formation in G. atropalpus but are released at eclosion independently of blood feeding. These results collectively suggest that blood meal dependent release of OEH and ILP3 is one factor that prevents A. aegypti from reproducing autogenously. Here, we examined two other factors that potentially inhibit autogeny in A. aegypti: teneral nutrient reserves and the ability of OEH and ILP3 to stimulate egg formation in the absence of blood feeding. Measures of nutrient reserves showed that newly emerged A. aegypti females had similar wet weights but significantly lower protein and glycogen reserves than G. atropalpus females when larvae were reared under identical conditions. OEH stimulated non-blood fed A. aegypti females to produce ecdysteroid hormone and package yolk into oocytes more strongly than ILP3. OEH also reduced host seeking and blood feeding behavior, yet females produced few mature eggs. Overall, our results indicate that multiple factors prevent A. aegypti from reproducing autogenously. PMID:26255841

  3. 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.

  4. Wolbachia Blocks Currently Circulating Zika Virus Isolates in Brazilian Aedes aegypti Mosquitoes

    OpenAIRE

    Dutra, Heverton Leandro Carneiro; Rocha, Marcele Neves; Dias, Fernando Braga Stehling; Mansur, Simone Brutman; Caragata, Eric Pearce; Moreira, Luciano Andrade

    2016-01-01

    Summary The recent association of Zika virus with cases of microcephaly has sparked a global health crisis and highlighted the need for mechanisms to combat the Zika vector, Aedes aegypti mosquitoes. Wolbachia pipientis, a bacterial endosymbiont of insect, has recently garnered attention as a mechanism for arbovirus control. Here we report that Aedes aegypti harboring Wolbachia are highly resistant to infection with two currently circulating Zika virus isolates from the recent Brazilian epide...

  5. Chikungunya virus susceptibility & variation in populations of Aedes aegypti (Diptera: Culicidae mosquito from India

    Directory of Open Access Journals (Sweden)

    Mangesh D Gokhale

    2015-01-01

    Full Text Available Background & objectives: Although having immense clinical relevance, yet only a few studies have been targeted to understand the chikungunya virus (CHIKV susceptibility and growth in Aedes aegypti populations from India. This study was undertaken to investigate CHIKV susceptibility and growth kinetics in Ae. aegypti along with genetic heterogeneity of Ae. aegypti populations. Methods: Dose dependent CHIKV susceptibility and growth kinetic studies for three CHIKV strains reported from India were carried out in Ae. aegypti mosquito populations. The phenotypic variation and genetic heterogeneity in five Ae. aegypti populations were investigated using multivariate morphometrics and allozyme variation studies. Results: The dissemination and growth kinetics studies of the three CHIKV strains showed no selective advantage for a particular strain of CHIKV in Ae. aegypti. At 100 per cent infection rate, five geographic Ae. aegypti populations showed differences in dissemination to three CHIKV strains. Morphometric studies revealed phenotypic variation in all the studied populations. The allelic frequencies, F statistics, and Nei′s genetic identity values showed that genetic differences between the populations were small, but significant. Interpretation & conclusions: The results obtained in this study suggest that genetic background of the vector strongly influences the CHIKV susceptibility in Ae. aegypti.

  6. Limited dengue virus replication in field-collected Aedes aegypti mosquitoes infected with Wolbachia.

    Directory of Open Access Journals (Sweden)

    Francesca D Frentiu

    2014-02-01

    Full Text Available INTRODUCTION: Dengue is one of the most widespread mosquito-borne diseases in the world. The causative agent, dengue virus (DENV, is primarily transmitted by the mosquito Aedes aegypti, a species that has proved difficult to control using conventional methods. The discovery that A. aegypti transinfected with the wMel strain of Wolbachia showed limited DENV replication led to trial field releases of these mosquitoes in Cairns, Australia as a biocontrol strategy for the virus. METHODOLOGY/PRINCIPAL FINDINGS: Field collected wMel mosquitoes that were challenged with three DENV serotypes displayed limited rates of body infection, viral replication and dissemination to the head compared to uninfected controls. Rates of dengue infection, replication and dissemination in field wMel mosquitoes were similar to those observed in the original transinfected wMel line that had been maintained in the laboratory. We found that wMel was distributed in similar body tissues in field mosquitoes as in laboratory ones, but, at seven days following blood-feeding, wMel densities increased to a greater extent in field mosquitoes. CONCLUSIONS/SIGNIFICANCE: Our results indicate that virus-blocking is likely to persist in Wolbachia-infected mosquitoes after their release and establishment in wild populations, suggesting that Wolbachia biocontrol may be a successful strategy for reducing dengue transmission in the field.

  7. Dengue virus 3 genotype I in Aedes aegypti mosquitoes and eggs, Brazil, 2005-2006.

    Science.gov (United States)

    Vilela, Ana P P; Figueiredo, Leandra B; dos Santos, João R; Eiras, Alvaro E; Bonjardim, Cláudio A; Ferreira, Paulo C P; Kroon, Erna G

    2010-06-01

    Dengue virus type 3 genotype I was detected in Brazil during epidemics in 2002-2004. To confirm this finding, we identified this virus genotype in naturally infected field-caught Aedes aegypti mosquitoes and eggs. Results showed usefulness of virus investigations in vectors as a component of active epidemiologic surveillance. PMID:20507754

  8. Chikungunya Virus in Febrile Humans and Aedes aegypti Mosquitoes, Yucatan, Mexico

    Science.gov (United States)

    Cigarroa-Toledo, Nohemi; Blitvich, Bradley J.; Cetina-Trejo, Rosa C.; Talavera-Aguilar, Lourdes G.; Baak-Baak, Carlos M.; Torres-Chablé, Oswaldo M.; Hamid, Md-Nafiz; Friedberg, Iddo; González-Martinez, Pedro; Alonzo-Salomon, Gabriela; Rosado-Paredes, Elsy P.; Rivero-Cárdenas, Nubia; Reyes-Solis, Guadalupe C.; Farfan-Ale, Jose A.; Garcia-Rejon, Julian E.

    2016-01-01

    Chikungunya virus (CHIKV) was isolated from 12 febrile humans in Yucatan, Mexico, in 2015. One patient was co-infected with dengue virus type 1. Two additional CHIKV isolates were obtained from Aedes aegypti mosquitoes collected in the homes of patients. Phylogenetic analysis showed that the CHIKV isolates belong to the Asian lineage. PMID:27347760

  9. 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 ef

  10. 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...

  11. Mosquito larvicidal activity of aromatic medicinal plant oils against Aedes aegypti and Culex pipiens pallens.

    Science.gov (United States)

    Lee, Hoi-Seon

    2006-06-01

    Larvicidal activity of essential oils derived from 11 aromatic medicinal plants against early 4th-stage larvae of Aedes aegypti and Culex pipiens pallens was tested in the laboratory. At 100 ppm, the essential oils of all plants caused 100% mortality against Ae. aegypti and Cx. pipiens pallens. At 25 ppm, the essential oils of Citrus bergamia, Cuminum myrrha, and Pimenta racemosa caused 100% mortality against larvae of Ae. aegypti and Cx. pipiens pallens. The oil of C. begamia caused 32.5% and 24.5% mortality against Ae. aegypti and Cx. pipiens pallens at 12.5 ppm, but 24.2% and 0% mortality against Ae. aegypti and Cx. pipiens pallens at 6.25 ppm, respectively. The oil of P. racemosa caused 52.3% and 38.5% mortality against Ae. aegypti and Cx. pipiens pallens at 12.5 ppm, but 32.2% and 0% mortality against Ae. aegypti and Cx. pipiens pallens at 6.25 ppm, respectively. The larvicidal activity of oils of C. bergamia, C. myrrha, and P. racemosa was significantly reduced when used at 6.25 ppm. These plants warrant further studies as possible agents for mosquito control.

  12. Wolbachia Blocks Currently Circulating Zika Virus Isolates in Brazilian Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Dutra, Heverton Leandro Carneiro; Rocha, Marcele Neves; Dias, Fernando Braga Stehling; Mansur, Simone Brutman; Caragata, Eric Pearce; Moreira, Luciano Andrade

    2016-06-01

    The recent association of Zika virus with cases of microcephaly has sparked a global health crisis and highlighted the need for mechanisms to combat the Zika vector, Aedes aegypti mosquitoes. Wolbachia pipientis, a bacterial endosymbiont of insect, has recently garnered attention as a mechanism for arbovirus control. Here we report that Aedes aegypti harboring Wolbachia are highly resistant to infection with two currently circulating Zika virus isolates from the recent Brazilian epidemic. Wolbachia-harboring mosquitoes displayed lower viral prevalence and intensity and decreased disseminated infection and, critically, did not carry infectious virus in the saliva, suggesting that viral transmission was blocked. Our data indicate that the use of Wolbachia-harboring mosquitoes could represent an effective mechanism to reduce Zika virus transmission and should be included as part of Zika control strategies. PMID:27156023

  13. 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.

  14. Imidacloprid impairs the post-embryonic development of the midgut in the yellow fever mosquito Stegomyia aegypti (=Aedes aegypti).

    Science.gov (United States)

    Fernandes, K M; Gonzaga, W G; Pascini, T V; Miranda, F R; Tomé, H V V; Serrão, J E; Martins, G F

    2015-09-01

    The mosquito Stegomyia aegypti (=Aedes aegypti) (Diptera: Culicidae) is a vector for the dengue and yellow fever viruses. As blood digestion occurs in the midgut, this organ constitutes the route of entry of many pathogens. The effects of the insecticide imidacloprid on the survival of St. aegypti were investigated and the sub-lethal effects of the insecticide on midgut development were determined. Third instar larvae were exposed to different concentrations of imidacloprid (0.15, 1.5, 3.0, 6.0 and 15.0 p.p.m.) and survival was monitored every 24 h for 10 days. Midguts from imidacloprid-treated insects at different stages of development were dissected and processed for analyses by transmission electron microscopy, immunofluorescence microscopy and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assays. Imidacloprid concentrations of 3.0 and 15.0 p.p.m. were found to affect midgut development similarly. Digestive cells of the fourth instar larvae (L4) midgut exposed to imidacloprid had more multilamellar bodies, abundantly found in the cell apex, and more electron-lucent vacuoles in the basal region compared with those from untreated insects. Moreover, imidacloprid interfered with the differentiation of regenerative cells, dramatically reducing the number of digestive and endocrine cells and leading to malformation of the midgut epithelium in adults. The data demonstrate that imidacloprid can reduce the survival of mosquitoes and thus indicate its potentially high efficacy in the control of St. aegypti populations.

  15. An integrated linkage, chromosome, and genome map for the yellow fever mosquito Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Vladimir A Timoshevskiy

    Full Text Available BACKGROUND: Aedes aegypti, the yellow fever mosquito, is an efficient vector of arboviruses and a convenient model system for laboratory research. Extensive linkage mapping of morphological and molecular markers localized a number of quantitative trait loci (QTLs related to the mosquito's ability to transmit various pathogens. However, linking the QTLs to Ae. aegypti chromosomes and genomic sequences has been challenging because of the poor quality of polytene chromosomes and the highly fragmented genome assembly for this species. METHODOLOGY/PRINCIPAL FINDINGS: Based on the approach developed in our previous study, we constructed idiograms for mitotic chromosomes of Ae. aegypti based on their banding patterns at early metaphase. These idiograms represent the first cytogenetic map developed for mitotic chromosomes of Ae. aegypti. One hundred bacterial artificial chromosome clones carrying major genetic markers were hybridized to the chromosomes using fluorescent in situ hybridization. As a result, QTLs related to the transmission of the filarioid nematode Brugia malayi, the avian malaria parasite Plasmodium gallinaceum, and the dengue virus, as well as sex determination locus and 183 Mbp of genomic sequences were anchored to the exact positions on Ae. aegypti chromosomes. A linear regression analysis demonstrated a good correlation between positions of the markers on the physical and linkage maps. As a result of the recombination rate variation along the chromosomes, 12 QTLs on the linkage map were combined into five major clusters of QTLs on the chromosome map. CONCLUSION: This study developed an integrated linkage, chromosome, and genome map-iMap-for the yellow fever mosquito. Our discovery of the localization of multiple QTLs in a few major chromosome clusters suggests a possibility that the transmission of various pathogens is controlled by the same genomic loci. Thus, the iMap will facilitate the identification of genomic determinants of

  16. 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; Alun L Lloyd; 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...

  17. 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 now surpassed the proof of principle stage and is now utilised 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). PMID:26443221

  18. 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.

  19. 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.

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

    OpenAIRE

    Hati A K; Bhowmik Keya; Banerjee A; Mukherjee H; Poddar G; Basu D; Dhara K P

    1995-01-01

    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 ...

  1. Mosquito adulticidal properties of Delonix elata (Family:Fabaceae) against dengue vector, Aedes aegypti (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Mohan Rajeswary; Marimuthu Govindarajan

    2014-01-01

    Objective:To determine the adulticidal activity of hexane, benzene, chloroform, ethyl acetate and methanol leaf and seed extracts of Delonix elata (D. elata) against Aedes aegypti (Ae. aegypti). Methods:The bioassay was conducted in an experimental kit consisting of two cylindrical plastic tubes both measuring 125 mm×44 mm following the WHO method;mortality of the mosquitoes was recorded after 24 h. Results:The adulticidal activity of plant leaf and seed extracts showed moderate toxic effect on the adult mosquitoes after 24 h of exposure period. However, the highest adulticidal activity was observed in the leaf methanol extract of D. elata against Ae. aegypti with the LC50 and LC90 values 162.87 and 309.32 mg/L, respectively. Conclusions:From this result, it can be concluded the crude extract of D. elata was an excellent potential for controlling Ae. aegypti mosquitoes.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Dynamics of the "popcorn" Wolbachia infection in outbred Aedes aegypti informs prospects for mosquito vector control.

    Science.gov (United States)

    Yeap, H L; Mee, P; Walker, T; Weeks, A R; O'Neill, S L; Johnson, P; Ritchie, S A; Richardson, K M; Doig, C; Endersby, N M; Hoffmann, A A

    2011-02-01

    Forty percent of the world's population is at risk of contracting dengue virus, which produces dengue fever with a potentially fatal hemorrhagic form. The wMelPop Wolbachia infection of Drosophila melanogaster reduces life span and interferes with viral transmission when introduced into the mosquito Aedes aegypti, the primary vector of dengue virus. Wolbachia has been proposed as an agent for preventing transmission of dengue virus. Population invasion by Wolbachia depends on levels of cytoplasmic incompatibility, fitness effects, and maternal transmission. Here we characterized these traits in an outbred genetic background of a potential target population of Ae. aegypti using two crossing schemes. Cytoplasmic incompatibility was strong in this background, and the maternal transmission rate of Wolbachia was high. The infection substantially reduced longevity of infected adult females, regardless of whether adults came from larvae cultured under high or low levels of nutrition or density. The infection reduced the viability of diapausing and nondiapausing eggs. Viability was particularly low when eggs were laid by older females and when diapausing eggs had been stored for a few weeks. The infection affected mosquito larval development time and adult body size under different larval nutrition levels and densities. The results were used to assess the potential for wMelPop-CLA to invade natural populations of Ae. aegypti and to develop recommendations for the maintenance of fitness in infected mosquitoes that need to compete against field insects. PMID:21135075

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

    Directory of Open Access Journals (Sweden)

    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.

  5. The influence of diet on the use of near-infrared spectroscopy to determine the age of female Aedes aegypti mosquitoes

    Science.gov (United States)

    Interventions targeting adult mosquitoes are used to combat transmission of vector-borne diseases, including dengue. Without available vaccines, targeting the primary vector, Aedes aegypti, is essential to prevent transmission. Older mosquitoes (>/='7 days) are of greatest epidemiological significan...

  6. An in vitro bioassay for the quantitative evaluation of mosquito repellents against Stegomyia aegypti (=Aedes aegypti) mosquitoes using a novel cocktail meal.

    Science.gov (United States)

    Huang, T-H; Tien, N-Y; Luo, Y-P

    2015-09-01

    To assess the efficacy of new insect repellents, an efficient and safe in vitro bioassay system using a multiple-membrane blood-feeding device and a cocktail meal was developed. The multiple-membrane blood-feeding device facilitates the identification of new insect repellents by the high-throughput screening of candidate chemicals. A cocktail meal was developed as a replacement for blood for feeding females of Stegomyia aegypti (=Aedes aegypti) (L.) (Diptera: Culicidae). The cocktail meal consisted of a mixture of salt, albumin and dextrose, to which adenosine triphosphate was added to induce engorging. Feeding rates of St. aegypti on the cocktail meal and pig blood, respectively, did not differ significantly, but were significantly higher than the feeding rate on citrate phosphate dextrose-adenine 1 (CPDA-1) solutions, which had been used to replace bloodmeals in previous repellent assays. Dose-dependent biting inhibition rates were analysed using probit analysis. The RD(50) (the dose producing 50% repellence of mosquito feeding) values of DEET, citronella, carvacrol, geraniol, eugenol and thymol were 1.62, 14.40, 22.51, 23.29, 23.83 and 68.05 µg/cm(2), respectively. PMID:25828787

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

    Directory of Open Access Journals (Sweden)

    Guadalupe Del Carmen Reyes-Solis

    2014-10-01

    Full Text Available 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.

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

    OpenAIRE

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

    2014-01-01

    Background: 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. Methods: 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. Results: LC50 values of water, etha...

  9. Aedes aegypti mosquitoes exhibit decreased repellency by DEET following previous exposure.

    Directory of Open Access Journals (Sweden)

    Nina M Stanczyk

    Full Text Available DEET (N,N-Diethyl-m-toluamide is one of the most widely used mosquito repellents. Although DEET has been shown to be extremely effective, recent studies have revealed that certain individual insects are unaffected by its presence. A genetic basis for this has been shown in Aedes aegypti mosquitoes and the fruit fly Drosophila melanogaster, but, for the triatomine bug, Rhodnius prolixus, a decrease in response to DEET occurred shortly after previous exposure, indicating that non-genetic factors may also be involved in DEET "insensitivity". In this study, we examined host-seeking behaviour and electrophysiological responses of A. aegypti after pre-exposure to DEET. We found that three hours after pre-exposure the mosquitoes showed behavioural insensitivity, and electroantennography revealed this correlated with the olfactory receptor neurons responding less to DEET. The change in behaviour as a result of pre-exposure to DEET has implications for the use of repellents and the ability of mosquitoes to overcome them.

  10. Bioefficacy of Mentha piperita essential oil against dengue fever mosquito Aedes aegypti L

    Science.gov (United States)

    Kumar, Sarita; Wahab, Naim; Warikoo, Radhika

    2011-01-01

    Objective To assess the larvicidal and repellent potential of the essential oil extracted from the leaves of peppermint plant, Mentha piperita (M. piperita) against the larval and adult stages of Aedes aegypti (Ae. Aegypti). Methods The larvicidal potential of peppermint oil was evaluated against early fourth instar larvae of Ae. aegypti using WHO protocol. The mortality counts were made after 24 and 48 h, and LC50 and LC90 values were calculated. The efficacy of peppermint oil as mosquito repellent was assessed using the human-bait technique. The measured area of one arm of a human volunteer was applied with the oil and the other arm was applied with ethanol. The mosquito bites on both the arms were recorded for 3 min after every 15 min. The experiment continued for 3 h and the percent protection was calculated. Results The essential oil extracted from M. piperita possessed excellent larvicidal efficiency against dengue vector. The bioassays showed an LC50 and LC90 value of 111.9 and 295.18 ppm, respectively after 24 h of exposure. The toxicity of the oil increased 11.8% when the larvae were exposed to the oil for 48 h. The remarkable repellent properties of M. piperita essential oil were established against adults Ae. aegypti. The application of oil resulted in 100% protection till 150 min. After next 30 min, only 1-2 bites were recorded as compared with 8-9 bites on the control arm. Conclusions The peppermint essential oil is proved to be efficient larvicide and repellent against dengue vector. Further studies are needed to identify the possible role of oil as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the oil could help in formulating strategies for mosquito control. PMID:23569733

  11. Bioefficacy ofMentha piperita essential oil against dengue fever mosquito Aedes aegypti L

    Institute of Scientific and Technical Information of China (English)

    Sarita Kumar; Naim Wahab; Radhika Warikoo

    2011-01-01

    Objective:To assess the larvicidal and repellent potential of the essential oil extracted from the leaves of peppermint plant,Mentha piperita (M. piperita) against the larval and adult stages of Aedes aegypti (Ae. Aegypti).Methods: The larvicidal potential of peppermint oil was evaluated against early fourth instar larvae ofAe. aegypti usingWHO protocol. The mortality counts were made after 24 and48 h, and LC50 and LC90values were calculated. The efficacy of peppermint oil as mosquito repellent was assessed using the human-bait technique. The measured area of one arm of a human volunteer was applied with the oil and the other arm was applied with ethanol. The mosquito bites on both the arms were recorded for3 min after every15 min. The experiment continued for 3 h and the percent protection was calculated.Results:The essential oil extracted fromM. piperita possessed excellent larvicidal efficiency against dengue vector. The bioassays showed an LC50 and LC90 value of111.9 and295.18 ppm, respectively after24 h of exposure. The toxicity of the oil increased11.8% when the larvae were exposed to the oil for48 h. The remarkable repellent properties ofM. piperita essential oil were established against adults Ae. aegypti. The application of oil resulted in100% protection till150 min. After next30min, only1-2 bites were recorded as compared with8-9 bites on the control arm.Conclusions:The peppermint essential oil is proved to be efficient larvicide and repellent against dengue vector. Further studies are needed to identify the possible role of oil as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the oil could help in formulating strategies for mosquito control.

  12. Wolbachia infection reduces blood-feeding success in the dengue fever mosquito, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Andrew P Turley

    Full Text Available BACKGROUND: The mosquito Aedes aegypti was recently transinfected with a life-shortening strain of the endosymbiont Wolbachia pipientis (wMelPop as the first step in developing a biocontrol strategy for dengue virus transmission. In addition to life-shortening, the wMelPop-infected mosquitoes also exhibit increased daytime activity and metabolic rates. Here we sought to quantify the blood-feeding behaviour of Wolbachia-infected females as an indicator of any virulence or energetic drain associated with Wolbachia infection. METHODOLOGY/PRINCIPAL FINDINGS: In a series of blood-feeding trials in response to humans, we have shown that Wolbachia-infected mosquitoes do not differ in their response time to humans, but that as they age they obtain fewer and smaller blood meals than Wolbachia-uninfected controls. Lastly, we observed a behavioural characteristic in the Wolbachia infected mosquitoes best described as a "bendy" proboscis that may explain the decreased biting success. CONCLUSIONS/SIGNIFICANCE: Taken together the evidence suggests that wMelPop infection may be causing tissue damage in a manner that intensifies with mosquito age and that leads to reduced blood-feeding success. These behavioural changes require further investigation with respect to a possible physiological mechanism and their role in vectorial capacity of the insect. The selective decrease of feeding success in older mosquitoes may act synergistically with other Wolbachia-associated traits including life-shortening and viral protection in biocontrol strategies.

  13. Deltamethrin:Promising mosquito control agent against adult stage of Aedes aegypti L

    Institute of Scientific and Technical Information of China (English)

    Sarita Kumar; Anita Thomas; Pillai MKK

    2011-01-01

    Objective:To evaluate the effects of deltamethrin against field-collected adults of Aedes aegypti L. (Ae. aegypti). Methods: The adults were selected with 0.025%deltamethrin for 40 successive generations. The selected adults were tested with 4%DDT and the emerging larvae were tested with various insecticides to study the cross-resistance spectrum. The knockdown and irritability studies were carried out in adult mosquitoes to investigate their behavioural response to deltamethrin. Results:Forty generations of selection with deltamethrin resulted in only 3.8-fold resistance in the adults of Ae. aegypti. The adults of parent (PS) and selected strains (DAS) exhibited only 0.8-fold cross resistance to 4%DDT. The larvae emerging from the PS and DAS strains did not develop appreciable levels of resistance to various insecticides tested. The knockdown studies revealed KT50 of 14.4 min in PS adults with no signs of recovery even after 24 h. The DAS strains could develop only 1.2 to 1.3-fold knockdown resistance (KDR). The knockdown response of DDT was though 5-6 times slower than deltamethrin but the continued response in deltamethrin-selected adults caused only 1.2-fold KDR. The PS and DAS strains exhibited significant irritability response towards deltamethrin and DDT. The DAS strains showed 5-6 fold increased irritability to deltamethrin as compared to the PS strain. Conclusions:The above results suggest the prolonged effective use of deltamethrin against Ae. aegypti as an adulticide.

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

    Directory of Open Access Journals (Sweden)

    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

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

    OpenAIRE

    Tarek M.Y. El-Sheikh; Zarrag I.A. Al-Fifi; Mohamed A. Alabboud

    2016-01-01

    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...

  16. Genetic selection of a flavivirus-refractory strain of the yellow fever mosquito Aedes aegypti.

    Science.gov (United States)

    Miller, B R; Mitchell, C J

    1991-10-01

    Two inbred (isofemale) Aedes aegypti mosquito lines were derived that manifested a resistant or susceptible phenotype following ingestion of yellow fever virus; lack of virus movement from the midgut defined the resistant phenotype. Other flaviviruses, including dengue 1-4, Uganda S, and Zika, viruses behaved in a similar fashion in the two mosquito lines. Crosses between the two lines produced progeny that were of intermediate susceptibility, indicating codominance; F2 backcrosses to the parents yielded results consistent with a major controlling genetic locus and provide evidence of a second locus capable of modulating the phenotype of the major gene. The rapid selection necessary to fix the susceptible and refractory phenotypes support the hypothesis of a single major controlling locus. Viral movement across the midgut is likely to be governed by a single major gene and modifying minor genes or a group of closely linked genes. These inbred mosquito lines will be useful in discovering the molecular basis for flavivirus resistance in Ae. aegypti.

  17. 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.

  18. 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  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  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. PMID:26693718

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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. 

  3. A piperidine amide extracted from Piper longum L. fruit shows activity against Aedes aegypti mosquito larvae.

    Science.gov (United States)

    Yang, Young-Cheol; Lee, Sang-Guei; Lee, Hee-Kwon; Kim, Moo-Key; Lee, Sang-Hyun; Lee, Hoi-Seon

    2002-06-19

    Mosquito larvicidal activity of Piper longum fruit-derived materials against the fourth-instar larvae of Aedes aegypti was examined. A crude methanol extract of P. longum fruits was found to be active against the larvae, and the hexane fraction of the methanol extract showed a strong larvicidal activity of 100% mortality. The biologically active component of P. longum fruits was characterized as pipernonaline by spectroscopic analyses. The LC(50) value of pipernonaline was 0.25 mg/L. The toxicity of pipernonaline is comparable to that of pirimiphos-methyl as a mosquito larvicide. In tests with available components derived from P. longum, no activity was observed with piperettine, piperine, or piperlongumine.

  4. 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.

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

    OpenAIRE

    Ong, Song-Quan; Jaal, Zairi

    2015-01-01

    Background 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. Methods 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 let...

  6. A study on container breeding mosquitoes with special reference to Aedes (Stegomyia aegypti and Aedes albopictus in Thiruvananthapuram district, India

    Directory of Open Access Journals (Sweden)

    K. Vijayakumar

    2014-01-01

    Full Text Available Background & objectives: The district of Thiruvananthapuram reports the maximum number of cases of dengue in the state of Kerala. To determine the larval diversity, density and breeding site preferences of Aedes mosquitoes, during pre-monsoon and monsoon periods in urban and rural areas of Thiruvananthapuram district. Methods: Based on the daily reports of dengue cases, 70 clusters were identified in Thiruvananthapuram district. A cross-sectional larval survey was done in the domestic and peri-domestic areas of 1750 houses, using the WHO standard techniques. The larval indices were calculated, and the larvae were identified by using taxonomic keys. Urban and rural differences and the variations during pre-monsoon and monsoon seasons were also studied. Results: In the surveyed houses, 15% had mosquito breeding, with 88% having Aedes larvae. The house index, container index and the breteau index were 13.08, 13.28 and 16.57%, respectively. About 86% of the clusters were found positive for Aedes albopictus and 11% for Ae. aegypti. Aedes albopictus was distributed almost equally in rural and urban clusters, whereas the distribution of Ae. aegypti was significantly higher in urban areas (p = 0.03. The most common water holding containers found (outdoor were of plastic, followed by coconut shells. The breeding preference ratio was highest for tyres. Significantly lesser positivity was found for containers during monsoon period when compared to pre-monsoon period. Conclusion: The geographical distribution of Ae. albopictus is significantly high in peri-domestic areas and, therefore, its epidemiological role in the widespread disease occurrence needs to be studied. The discarded tyres being the most preferred breeding sites, where IEC activities will help in source reduction.

  7. Mosquito larvicidal potential of silver nanoparticles synthesized using Chomelia asiatica (Rubiaceae) against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Muthukumaran, Udaiyan; Govindarajan, Marimuthu; Rajeswary, Mohan

    2015-03-01

    Mosquitoes transmit serious human diseases, causing millions of deaths every year. Mosquito control is to enhance the health and quality of life of county residents and visitors through the reduction of mosquito populations. Mosquito control is a serious concern in developing countries like India due to the lack of general awareness, development of resistance, and socioeconomic reasons. Today, nanotechnology is a promising research domain which has a wide ranging application in vector control programs. These are nontoxic, easily available at affordable prices, biodegradable, and show broad-spectrum target-specific activities against different species of vector mosquitoes. In the present study, larvicidal activity of aqueous leaf extract and silver nanoparticles (AgNPs) synthesized using C. asiatica plant leaves against late third instar larvae of Anopheles stephensi, Aedes aegypti, and Cx. quinquefasciatus. The range of varying concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg/mL) and aqueous leaf extract (40, 80, 120, 160, and 200 μg/mL) were tested against the larvae of An. stephensi, Ae. aegypti, and Cx. quinquefasciatus. The synthesized AgNPs from C. asiatica were highly toxic than crude leaf aqueous extract in three important vector mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis (EDX). Considerable mortality was evident after the treatment of C. asiatica for all three important vector mosquitoes. The LC50 and LC90 values of C. asiatica aqueous leaf extract appeared to be effective against An. stephensi (LC50, 90.17 μg/mL; LC90, 165.18 μg/mL) followed by Ae. aegypti (LC50, 96.59 μg/mL; LC90, 173.83 μg/mL) and Cx. quinquefasciatus (LC50, 103.08 μg/mL; LC90, 183.16 μg/mL). Synthesized AgNPs against the vector mosquitoes of An. stephensi, Ae. aegypti, and Cx. quinquefasciatus had the following LC50 and LC90

  8. Spatial genetic structure of Aedes aegypti mosquitoes in mainland Southeast Asia.

    Science.gov (United States)

    Hlaing, Thaung; Tun-Lin, Willoughby; Somboon, Pradya; Socheat, Duong; Setha, To; Min, Sein; Thaung, Sein; Anyaele, Okorie; De Silva, Babaranda; Chang, Moh Seng; Prakash, Anil; Linton, Yvonne; Walton, Catherine

    2010-07-01

    Aedes aegypti mosquitoes originated in Africa and are thought to have spread recently to Southeast Asia, where they are the major vector of dengue. Thirteen microsatellite loci were used to determine the genetic population structure of A. aegypti at a hierarchy of spatial scales encompassing 36 sites in Myanmar, Cambodia and Thailand, and two sites in Sri Lanka and Nigeria. Low, but significant, genetic structuring was found at all spatial scales (from 5 to >2000 km) and significant F IS values indicated genetic structuring even within 500 m. Spatially dependent genetic-clustering methods revealed that although spatial distance plays a role in shaping larger-scale population structure, it is not the only factor. Genetic heterogeneity in major port cities and genetic similarity of distant locations connected by major roads, suggest that human transportation routes have resulted in passive long-distance migration of A. aegypti. The restricted dispersal on a small spatial scale will make localized control efforts and sterile insect technology effective for dengue control. Conversely, preventing the establishment of insecticide resistance genes or spreading refractory genes in a genetic modification strategy would be challenging. These effects on vector control will depend on the relative strength of the opposing effects of passive dispersal. PMID:25567928

  9. Intraspecific DNA variation in nuclear genes of the mosquito Aedes aegypti.

    Science.gov (United States)

    Morlais, I; Severson, D W

    2003-12-01

    Single nucleotide polymorphisms (SNPs) are an abundant source of genetic variation among individual organisms. To assess the usefulness of SNPs for genome analysis in the yellow fever mosquito, Aedes aegypti, we sequenced 25 nuclear genes in each of three strains and analysed nucleotide diversity. The average frequency of nucleotide variation was 12 SNPs per kilobase, indicating that nucleotide variation in Ae. aegypti is similar to that in other organisms, including Drosophila and the malaria vector Anopheles gambiae. Transition polymorphisms outnumbered transversion polymorphisms, at a ratio of about 2:1. We examined codon usage and confirmed that mutational bias favours G and C ending codons. Codon bias was most pronounced in highly expressed genes. Nucleotide diversity estimates indicated that substitution rates are positively correlated in coding and non-coding regions. Nucleotide diversity varied from one gene to another. The unequal distribution of SNPs among Ae. aegypti nuclear genes suggests that single base variations are non-neutral and are subject to selective constraints. Our analysis showed that ubiquitously expressed genes have lower polymorphism rates and are likely under strong purifying selection, whereas tissue specific genes and genes with a putative role in parasite defence exhibit higher levels of polymorphism that may be associated with diversifying selection. PMID:14986924

  10. Effect of mosquito midgut trypsin activity on dengue-2 virus infection and dissemination in Aedes aegypti.

    Science.gov (United States)

    Molina-Cruz, Alvaro; Gupta, Lalita; Richardson, Jason; Bennett, Kristine; Black, William; Barillas-Mury, Carolina

    2005-05-01

    The effect of mosquito midgut trypsins in dengue serotype 2 flavivirus (DENV-2) infectivity to Aedes aegypti was studied. Addition of soybean trypsin inhibitor (STI) in a DENV-2 infectious blood meal resulted in a 91-97% decrease in midgut DENV-2 RNA copies (qRT-PCR analysis). STI treatment also resulted in slower DENV-2 replication in the midgut, less DENV-2 E protein expression, and decreased dissemination to the thorax and the head. A second uninfected blood meal, 7 days after the STI-treated infectious meal, significantly increased DENV-2 replication in the midgut and recovered oogenesis, suggesting that the lower viral infection caused by STI was in part due to a nutritional effect. Mosquitoes fed DENV-2 digested in vitro with bovine trypsin (before STI addition) exhibited a transient increase in midgut DENV-2 4 days postinfection. Blood digestion and possibly DENV-2 proteolytic processing, mediated by midgut trypsins, influence the rate of DENV-2 infection, replication, and dissemination in Ae. aegypti. PMID:15891140

  11. 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...

  12. Mosquito larvicidal and ovicidal properties of Eclipta alba (L.) Hassk (Asteraceae) against chikungunya vector, Aedes aegypti (Linn.) (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    M Govindarajan; P Karuppannan

    2011-01-01

    Objective: The present study deals with the investigation of larvicidal and ovicidal activities of benzene, hexane, ethyl acetate, methanol and chloroform leaf extract of Eclipta alba (E. alba) against dengue vector, Aedes aegypti (Ae. Aegypti). Methods: Twenty five early III instar larvae of Ae. aegypti was exposed to various concentrations (50-300 ppm) and was assayed in the laboratory by using the protocol of WHO 2005; the 24 h LC50 values of the E. alba leaf extract was determined by Probit analysis. For ovicidal activity, slightly modified method of Su and Mulla was performed. The ovicidal activity was determined against Ae. aegypti to various concentrations ranging from 100-350 ppm under the laboratory conditions. The egg hatch rates were assessed 48 h post treatment. Results: The LC50 values of benzene, hexane, ethyl acetate, methanol and chloroform extract of E. alba against early third instar larvae of Ae. aegypti were 151.38, 165.10, 154.88, 127.64 and 146.28 ppm, respectively. Maximum larvicidal activity was observed in the methanol extract followed by chloroform, benzene, ethyl acetate and hexane extract. No mortality was observed in control. Among five solvent tested the methanol extract was found to be most effective for ovicidal activity against Ae. aegypti. The methanol extracts exerted 100% mortality (zero hatchability) at 300 ppm. Conclusions: From the results it can be concluded the crude extract of E. alba was an excellent potential for controlling Ae. aegypti mosquito.

  13. Potential topical natural repellent against Ae. aegypti, Culex sp. and Anopheles sp. mosquitoes

    Directory of Open Access Journals (Sweden)

    Dewi Nur Hodijah

    2014-08-01

    Full Text Available AbstrakLatar belakang:Minyak atsiri daun sirih diketahui mempunyai daya proteksi. Dibuatkan losion berdasarkan pengantar sediaan farmasi yang ditambahkan minyak atsiri daun nilam. Sediaan losion dipilih agar dapat menempel lebih lama di permukaan kulit. Tujuan penelitian ini untuk membandingkan daya proteksi antara losion dengan penambahan minyak nilam dan losion tanpa penambahan minyak nilam dibandingkan daya proteksi dengan DEET. Metode: Penelitian ini merupakan penelitian eksperimental laboratorium. Semua nyamuk uji berasal dari insektarium laboratorium penelitian kesehatan Loka litbang P2B2 Ciamis. Konsentrasi minyak atsiri daun sirih dalam losion adalah 4%; konsentrasi minyak nilam sebagai zat pengikat adalah 0,4%. Formula yang digunakan yaitu formula dasar yang ada pada pengantar sediaan farmasi. Uji repelensi dilakukan dengan menggunakan metoda yang direkomendasikan oleh Komisi pestisida.Hasil: Dihasilkan formulasi losion yang stabil dan masih memenuhi standar formulasi sediaan. Berdasarkan hasil, diperoleh data bahwa DEET dan losion hasil modifikasi memiliki rata-rata daya proteksi di atas 90% selama 6 jam terhadap nyamuk Ae.aegypti dan Culex sp. Kesimpulan: Penambahan minyak nilam pada losion sirih dapat meningkatkan daya proteksi terhadap hinggapan nyamuk Ae. aegypti dan Culex sp. (Health Science Indones 2014;1:44-8Kata kunci:repelen alamiah, minyak atsiri, daun sirih, daun nilam, Ae. aegypti, Culex sp.AbstractBackground: Betel leaf essential oil lotion has been known to have insect repellent properties. A lotion was made based on a pharmaceutical formula from a monograph where patchouli leaf essential oil was added. A lotion preparation was intended to enhance adherence of the formula on the surface of the skin. The purpose of this study was to compare protection percentage of lotion with patchouli oil and without patchouli oil lotion compared to DEET.Methods: This study is an experimental laboratory-based research. All mosquitoes

  14. Chemical and biological insecticides select distinct gene expression patterns in Aedes aegypti mosquito.

    Science.gov (United States)

    Després, Laurence; Stalinski, Renaud; Faucon, Frédéric; Navratil, Vincent; Viari, Alain; Paris, Margot; Tetreau, Guillaume; Poupardin, Rodolphe; Riaz, Muhammad Asam; Bonin, Aurélie; Reynaud, Stéphane; David, Jean-Philippe

    2014-12-01

    Worldwide evolution of mosquito resistance to chemical insecticides represents a major challenge for public health, and the future of vector control largely relies on the development of biological insecticides that can be used in combination with chemicals (integrated management), with the expectation that populations already resistant to chemicals will not become readily resistant to biological insecticides. However, little is known about the metabolic pathways affected by selection with chemical or biological insecticides. Here we show that Aedes aegypti, a laboratory mosquito strain selected with a biological insecticide (Bacillus thuringiensis israelensis, Bti) evolved increased transcription of many genes coding for endopeptidases while most genes coding for detoxification enzymes were under-expressed. By contrast, in strains selected with chemicals, genes encoding detoxification enzymes were mostly over-expressed. In all the resistant strains, genes involved in immune response were under-transcribed, suggesting that basal immunity might be a general adjustment variable to compensate metabolic costs caused by insecticide selection. Bioassays generally showed no evidence for an increased susceptibility of selected strains towards the other insecticide type, and all chemical-resistant strains were as susceptible to Bti as the unselected parent strain, which is a good premise for sustainable integrated management of mosquito populations resistant to chemicals.

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

    Directory of Open Access Journals (Sweden)

    Nurhayat Tabanca

    2015-10-01

    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 .

  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)

    Science.gov (United States)

    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. Insecticidal potency of Aspergillus terreus against larvae and pupae of three mosquito species Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti.

    Science.gov (United States)

    Ragavendran, Chinnasamy; Natarajan, Devarajan

    2015-11-01

    Microbial control agents offer alternatives to chemical pest control, as they can be more selective than chemical insecticides. The present study evaluates the mosquito larvicidal and pupicidal potential of fungus mycelia using ethyl acetate and methanol solvent extracts produced by Aspergillus terreus against Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti. The A. terreus mycelia were extracted after 15 days from Sabouraud dextrose broth medium. The ethyl acetate extracts showed lethal concentration that kills 50% of the exposed larvae (LC50) and lethal concentration that kills 90% of the exposed larvae (LC90) values of the first, second, third, and fourth instar larvae of An. stephensi (LC50 = 97.410, 102.551, 29.802, and 8.907; LC90 = 767.957, 552.546, 535.474, and 195.677 μg/ml), Cx. quinquefasciatus (LC50 = 89.584, 74.689, 68.265, and 67.40; LC90 = 449.091, 337.355, 518.793, and 237.347 μg/ml), and Ae. aegypti (LC50 = 83.541, 84.418, 80.407, and 95.926; LC90 = 515.464, 443.167, 387.910, and 473.998 μg/ml). Pupicidal activity of mycelium extracts was tested against An. stephensi (LC50 = 25.228, LC90 = 140.487), Cx. quinquefasciatus (LC50 = 54.525, LC90 = 145.366), and Ae. aegypti (LC50 = 10.536, LC90 = 63.762 μg/ml). At higher concentration (500 μg/ml), mortality starts within the first 6 h of exposure. One hundred percent mortality occurs at 24-h exposure. The overall result observed that effective activity against selected mosquito larvae and pupae after 24 h was a dose and time-dependent activity. These ensure that the resultant mosquito population reduction is substantial even where the larvicidal and pupicidal potential is minimal. The FTIR spectra of ethyl acetate extract reflect prominent peaks (3448.32, 3000.36, 2914.59, 2118.73, 1668.21, 1436.87, 1409.02, 954.33, 901.13, and 704.67 cm(-1)). The spectra showed a sharp absorption band at 1314.66 cm(-1) assigned to wagging vibration of

  18. Insecticidal potency of Aspergillus terreus against larvae and pupae of three mosquito species Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti.

    Science.gov (United States)

    Ragavendran, Chinnasamy; Natarajan, Devarajan

    2015-11-01

    Microbial control agents offer alternatives to chemical pest control, as they can be more selective than chemical insecticides. The present study evaluates the mosquito larvicidal and pupicidal potential of fungus mycelia using ethyl acetate and methanol solvent extracts produced by Aspergillus terreus against Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti. The A. terreus mycelia were extracted after 15 days from Sabouraud dextrose broth medium. The ethyl acetate extracts showed lethal concentration that kills 50% of the exposed larvae (LC50) and lethal concentration that kills 90% of the exposed larvae (LC90) values of the first, second, third, and fourth instar larvae of An. stephensi (LC50 = 97.410, 102.551, 29.802, and 8.907; LC90 = 767.957, 552.546, 535.474, and 195.677 μg/ml), Cx. quinquefasciatus (LC50 = 89.584, 74.689, 68.265, and 67.40; LC90 = 449.091, 337.355, 518.793, and 237.347 μg/ml), and Ae. aegypti (LC50 = 83.541, 84.418, 80.407, and 95.926; LC90 = 515.464, 443.167, 387.910, and 473.998 μg/ml). Pupicidal activity of mycelium extracts was tested against An. stephensi (LC50 = 25.228, LC90 = 140.487), Cx. quinquefasciatus (LC50 = 54.525, LC90 = 145.366), and Ae. aegypti (LC50 = 10.536, LC90 = 63.762 μg/ml). At higher concentration (500 μg/ml), mortality starts within the first 6 h of exposure. One hundred percent mortality occurs at 24-h exposure. The overall result observed that effective activity against selected mosquito larvae and pupae after 24 h was a dose and time-dependent activity. These ensure that the resultant mosquito population reduction is substantial even where the larvicidal and pupicidal potential is minimal. The FTIR spectra of ethyl acetate extract reflect prominent peaks (3448.32, 3000.36, 2914.59, 2118.73, 1668.21, 1436.87, 1409.02, 954.33, 901.13, and 704.67 cm(-1)). The spectra showed a sharp absorption band at 1314.66 cm(-1) assigned to wagging vibration of

  19. 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

    2016-01-01

    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. PMID:27294950

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

    Directory of Open Access Journals (Sweden)

    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

  1. Insecticidal and repellent activity of Clausena dentata (Rutaceae) plant extracts against Aedes aegypti and Culex quinquefasciatus mosquitoes (Diptera: Culicidae).

    Science.gov (United States)

    Ramkumar, Govindaraju; Karthi, Sengodan; Muthusamy, Ranganathan; Natarajan, Devarajan; Shivakumar, Muthugounder Subramanian

    2015-03-01

    Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol agents. The present study is to evaluate adulticidal activity of Clausena dentata plant extract against Aedes aegypti and Culex quinquefasciatus mosquitoes. The adult mortality was observed after 24 h of exposure. The highest mortality was found in acetone extracts against Ae. aegypti and Cx. quinquefasciatus with the LC50 and LC90 4.1783 mg/ml (3.8201-7.1026), 9.3884 mg/ml (7. 8258-13.1820) and 4.2451 mg/ml (3.8547-8.0254), 12.3214 mg/ml (10.9287-16.2220), respectively. Smoke toxicity was observed at 10-min interval for 40 min, and the mortality data were recorded. Result shows that Ae. aegypti and Cx. quinquefasciatus are 85 ± 2 and 89 ± 1.5, respectively. A mortality of 100 % was recorded in the commercial mosquito control. These results suggest that the leaf extracts of C. dentata have a potential to be used as an ideal eco-friendly approach for the control of mosquitoes. PMID:25573693

  2. Insecticidal and repellent activity of Clausena dentata (Rutaceae) plant extracts against Aedes aegypti and Culex quinquefasciatus mosquitoes (Diptera: Culicidae).

    Science.gov (United States)

    Ramkumar, Govindaraju; Karthi, Sengodan; Muthusamy, Ranganathan; Natarajan, Devarajan; Shivakumar, Muthugounder Subramanian

    2015-03-01

    Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol agents. The present study is to evaluate adulticidal activity of Clausena dentata plant extract against Aedes aegypti and Culex quinquefasciatus mosquitoes. The adult mortality was observed after 24 h of exposure. The highest mortality was found in acetone extracts against Ae. aegypti and Cx. quinquefasciatus with the LC50 and LC90 4.1783 mg/ml (3.8201-7.1026), 9.3884 mg/ml (7. 8258-13.1820) and 4.2451 mg/ml (3.8547-8.0254), 12.3214 mg/ml (10.9287-16.2220), respectively. Smoke toxicity was observed at 10-min interval for 40 min, and the mortality data were recorded. Result shows that Ae. aegypti and Cx. quinquefasciatus are 85 ± 2 and 89 ± 1.5, respectively. A mortality of 100 % was recorded in the commercial mosquito control. These results suggest that the leaf extracts of C. dentata have a potential to be used as an ideal eco-friendly approach for the control of mosquitoes.

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

    Science.gov (United States)

    Hall-Mendelin, Sonja; Pyke, Alyssa T.; Moore, Peter R.; Mackay, Ian M.; McMahon, Jamie L.; Ritchie, Scott A.; Taylor, Carmel T.; Moore, Frederick A.J.; van den Hurk, Andrew F.

    2016-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance 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. PMID:27643685

  4. A Multipurpose, High-Throughput Single-Nucleotide Polymorphism Chip for the Dengue and Yellow Fever Mosquito, Aedes aegypti.

    Science.gov (United States)

    Evans, Benjamin R; Gloria-Soria, Andrea; Hou, Lin; McBride, Carolyn; Bonizzoni, Mariangela; Zhao, Hongyu; Powell, Jeffrey R

    2015-05-01

    The dengue and yellow fever mosquito, Aedes aegypti, contributes significantly to global disease burden. Genetic study of Aedes aegypti is essential to understanding its evolutionary history, competence as a disease vector, and the effects and efficacy of vector control methods. The prevalence of repeats and transposable elements in the Aedes aegypti genome complicates marker development and makes genome-wide genetic study challenging. To overcome these challenges, we developed a high-throughput genotyping chip, Axiom_aegypti1. This chip screens for 50,000 single-nucleotide polymorphisms present in Aedes aegypti populations from around the world. The array currently used genotypes 96 samples simultaneously. To ensure that these markers satisfy assumptions commonly made in many genetic analyses, we tested for Mendelian inheritance and linkage disequilibrium in laboratory crosses and a wild population, respectively. We have validated more than 25,000 of these markers to date, and expect this number to increase with more sampling. We also present evidence of the chip's efficacy in distinguishing populations throughout the world. The markers on this chip are ideal for applications ranging from population genetics to genome-wide association studies. This tool makes rapid, cost-effective, and comparable genotype data attainable to diverse sets of Aedes aegypti researchers, from those interested in potential range shifts due to climate change to those characterizing the genetic underpinnings of its competence to transmit disease. PMID:25721127

  5. Mechanisms of pyrethroid resistance in the dengue mosquito vector, Aedes aegypti: target site insensitivity, penetration, and metabolism.

    Directory of Open Access Journals (Sweden)

    Shinji Kasai

    2014-06-01

    Full Text Available Aedes aegypti is the major vector of yellow and dengue fevers. After 10 generations of adult selection, an A. aegypti strain (SP developed 1650-fold resistance to permethrin, which is one of the most widely used pyrethroid insecticides for mosquito control. SP larvae also developed 8790-fold resistance following selection of the adults. Prior to the selections, the frequencies of V1016G and F1534C mutations in domains II and III, respectively, of voltage-sensitive sodium channel (Vssc, the target site of pyrethroid insecticide were 0.44 and 0.56, respectively. In contrast, only G1016 alleles were present after two permethrin selections, indicating that G1016 can more contribute to the insensitivity of Vssc than C1534. In vivo metabolism studies showed that the SP strain excreted permethrin metabolites more rapidly than a susceptible SMK strain. Pretreatment with piperonyl butoxide caused strong inhibition of excretion of permethrin metabolites, suggesting that cytochrome P450 monooxygenases (P450s play an important role in resistance development. In vitro metabolism studies also indicated an association of P450s with resistance. Microarray analysis showed that multiple P450 genes were over expressed during the larval and adult stages in the SP strain. Following quantitative real time PCR, we focused on two P450 isoforms, CYP9M6 and CYP6BB2. Transcription levels of these P450s were well correlated with the rate of permethrin excretion and they were certainly capable of detoxifying permethrin to 4'-HO-permethrin. Over expression of CYP9M6 was partially due to gene amplification. There was no significant difference in the rate of permethrin reduction from cuticle between SP and SMK strains.

  6. Septic tanks as larval habitats for the mosquitoes Aedes aegypti and Culex quinquefasciatus in Playa-Playita, Puerto Rico.

    Science.gov (United States)

    Burke, R; Barrera, R; Lewis, M; Kluchinsky, T; Claborn, D

    2010-06-01

    Adult Aedes aegypti (Linnaeus) (Diptera: Culicidae) were previously recovered from emergence traps on septic tanks in southeastern Puerto Rico. In this study we quantified immature mosquito abundance and its relationship with structural variables of the septic tanks and chemical properties of the water containing raw sewage. A miniaturized floating funnel trap was used to sample 89 septic tanks for larvae in the Puerto Rican community of Playa-Playita. Aedes aegypti larvae were recovered from 18% of the sampled tanks (10.3 larvae per septic tank per day). Larval presence was positively associated with cracking of the septic tank walls and uncovered access ports. Larval abundance was positively associated with cracking of the septic tank walls and larger tank surface areas, and inversely associated with the total dissolved solids (TDS). Culex quinquefasciatus (Say) larvae were also recovered from 74% of the septic tanks (129.6 larvae per septic tank per day). Larval presence was negatively associated with TDS in the water and larval abundance was positively associated with cracking of the septic tank walls. A screened, plastic emergence trap was used to sample 93 septic tanks within the community for Ae. aegypti and Cx. quinquefasciatus adults. Aedes aegypti adults were recovered from 49% of the sampled tanks (8.7 adults per septic tank per day) and Cx. quinquefasciatus adults were recovered from 97% of the sampled tanks (155.5 adults per septic tank per day). Aedes aegypti adult presence was positively associated with cracking, uncapped openings and septic water pH. The Ae. aegypti adult counts were positively associated with cracking and inversely associated with TDS and conductivity. This study marks the first published record of the recovery of Ae. aegypti larvae from holding tanks containing raw sewage in the Caribbean region. Our study indicates that Ae. aegypti larvae are present in sewage water and that septic tanks have at least the potential to maintain

  7. 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.; Quattrochi, D.; MorenoMadrinan, M. J.

    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.

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

    Science.gov (United States)

    Mysore, Keshava; Sun, Longhua; Tomchaney, Michael; Sullivan, Gwyneth; Adams, Haley; Piscoya, Andres S; Severson, David W; Syed, Zainulabeuddin; Duman-Scheel, Molly

    2015-11-01

    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. PMID:26544686

  9. 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.

  10. 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.; Eisen, L.; Estes, M. G.; Estes, S. M.; Hayden, M.; Lozano-Fuentes, S.; Monaghan, A. J.; Moreno Madriñán, M. J.; Ochoa, C.; Quattrochi, D.; Tapia, B.; Welsh-Rodriguez, C. M.

    2012-12-01

    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.

  11. Mechanical transmission of Bacillus anthracis by stable flies (Stomoxys calcitrans) and mosquitoes (Aedes aegypti and Aedes taeniorhynchus).

    OpenAIRE

    Turell, M J; Knudson, G B

    1987-01-01

    We evaluated the potential of stable flies, Stomoxys calcitrans, and two species of mosquitoes, Aedes aegypti and Aedes taeniorhynchus, to transmit Bacillus anthracis Vollum 1B mechanically. After probing on Hartley guinea pigs with a bacteremia of ca. 10(8.6) CFU of B. anthracis per ml of blood, individual or pools of two to four stable flies or mosquitoes were allowed to continue feeding on either uninfected guinea pigs or A/J mice. All three insect species transmitted lethal anthrax infect...

  12. 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.

  13. Leucokinin mimetic elicits aversive behavior in mosquito Aedes aegypti (L.) and inhibits the sugar taste neuron.

    Science.gov (United States)

    Kwon, Hyeogsun; Ali Agha, Moutaz; Smith, Ryan C; Nachman, Ronald J; Marion-Poll, Frédéric; Pietrantonio, Patricia V

    2016-06-21

    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 protein-coupled kinin receptor designated "Aedae-KR." We used protease-resistant kinin analogs 1728, 1729, and 1460 to evaluate their effects on sucrose perception and feeding behavior. In no-choice feeding bioassays (capillary feeder and plate assays), the analog 1728, which contains α-amino isobutyric acid, inhibited females from feeding on sucrose. It further induced quick fly-away or walk-away behavior following contact with the tarsi and the mouthparts. Electrophysiological recordings from single long labellar sensilla of the proboscis demonstrated that mixing the analog 1728 at 1 mM with sucrose almost completely inhibited the detection of sucrose. Aedae-KR was immunolocalized in contact chemosensory neurons in prothoracic tarsi and in sensory neurons and accessory cells of long labellar sensilla in the distal labellum. Silencing Aedae-KR by RNAi significantly reduced gene expression and eliminated the feeding-aversion behavior resulting from contact with the analog 1728, thus directly implicating the Aedae-KR in the aversion response. To our knowledge, this is the first report that kinin analogs modulate sucrose perception in any insect. The aversion to feeding elicited by analog 1728 suggests that synthetic molecules targeting the mosquito Aedae-KR in the labellum and tarsi should be investigated for the potential to discover novel feeding deterrents of mosquito vectors. PMID:27274056

  14. Bioefficacy of crude extract of Cyperus aromaticus (Family:Cyperaceae) cultured cells, against Aedes aegypti and Aedes albopictus mosquitoes

    Institute of Scientific and Technical Information of China (English)

    Fatemeh Kamiabi; Zairi Jaal; Chan Lai Keng

    2013-01-01

    Objective:To evaluate the growth inhibition activity of the crude extract of Cyperus aromaticus (C. aromaticus) cultured cells against the 3rd instar larvae of Aedes aegypti (Linn.) and Aedes albopictus Skuse (Ae. albopictus) under laboratory conditions, and determine the sublethal effects (EI50) of the crude extract of C. aromaticus cultured cells on some biological and morphological parameters of both Aedes mosquito species during two generations as well. Methods:The cell suspension cultures of C. aromaticus were activated from five callus lines (P4, Pa, Z1, Z6 and Ml) derived from the root explants of in vitro plantlets. The cultured cells were extracted in chloroform and used as plant material for the present study. For detection of juvenile hormone III, the crude extracts were analyzed by HPLC. Then the crude extracts of the three C. aromaticus cultured cell lines which contained varied amounts of juvenile hormone III [high level (P4 cell line), medium level (Z1 cell line) and low level (Ml cell line)] were tested against Aedes mosquito species. Laboratory evaluation was performed against late third instar larvae of the Vector Control Research Unit strains of Ae. aegypti and Ae. albopictus using the standard WHO method. The effects of EI50 of the C. aromaticus cultured P4 cells on fecundity, fertility, growth period, sex ratio, adult size and longevity of Aedes mosquitoes were assessed. Results:Bioassay tests presented the remarkable growth inhibition activity of the crude extracts of C. aromaticus cultured cells against the two Aedes mosquitoes. Between the two mosquito species, Ae. albopictus was more susceptible to the crude extracts with lower EI50 values. EI50 of the crude extract of C. aromaticus cultured cells (P4) increased the sterility indices in the parental generation females in both Aedes mosquito species. A significant delay in the pupal formation and adult emergence were observed in the parental generation of the both mosquito species. The sex

  15. Ovicidal and Oviposition Deterrent Activities of Medicinal Plant Extracts Against Aedes aegypti L. and Culex quinquefasciatus Say Mosquitoes (Diptera: Culicidae)

    OpenAIRE

    Reegan, Appadurai Daniel; Gandhi, Munusamy Rajiv; Paulraj, Micheal Gabriel; Ignacimuthu, Savarimuthu

    2014-01-01

    Objectives To evaluate the ovicidal and oviposition deterrent activities of five medicinal plant extracts namely Aegle marmelos (Linn.), Limonia acidissima (Linn.), Sphaeranthus indicus (Linn.), Sphaeranthus amaranthoides (burm.f), and Chromolaena odorata (Linn.) against Culex quinquefasciatus and Aedes aegypti mosquitoes. Three solvents, namely hexane, ethyl acetate, and methanol, were used for the preparation of extracts from each plant. Methods Four different concentrations—62.5 parts per ...

  16. A spatial model with pulsed releases to compare strategies for the sterile insect technique applied to the mosquito Aedes aegypti

    OpenAIRE

    Evans, T. P. O.; Bishop, S.R.

    2014-01-01

    We present a simple mathematical model to replicate the key features of the sterile insect technique (SIT) for controlling pest species, with particular reference to the mosquito Aedes aegypti, the main vector of dengue fever. The model differs from the majority of those studied previously in that it is simultaneously spatially explicit and involves pulsed, rather than continuous, sterile insect releases. The spatially uniform equilibria of the model are identified and analysed. Simulations a...

  17. Establishment of a Wolbachia Superinfection in Aedes aegypti Mosquitoes as a Potential Approach for Future Resistance Management.

    Directory of Open Access Journals (Sweden)

    D Albert Joubert

    2016-02-01

    Full Text Available Wolbachia pipientis is an endosymbiotic bacterium estimated to chronically infect between 40-75% of all arthropod species. Aedes aegypti, the principle mosquito vector of dengue virus (DENV, is not a natural host of Wolbachia. The transinfection of Wolbachia strains such as wAlbB, wMel and wMelPop-CLA into Ae. aegypti has been shown to significantly reduce the vector competence of this mosquito for a range of human pathogens in the laboratory. This has led to wMel-transinfected Ae. aegypti currently being released in five countries to evaluate its effectiveness to control dengue disease in human populations. Here we describe the generation of a superinfected Ae. aegypti mosquito line simultaneously infected with two avirulent Wolbachia strains, wMel and wAlbB. The line carries a high overall Wolbachia density and tissue localisation of the individual strains is very similar to each respective single infected parental line. The superinfected line induces unidirectional cytoplasmic incompatibility (CI when crossed to each single infected parental line, suggesting that the superinfection would have the capacity to replace either of the single constituent infections already present in a mosquito population. No significant differences in fitness parameters were observed between the superinfected line and the parental lines under the experimental conditions tested. Finally, the superinfected line blocks DENV replication more efficiently than the single wMel strain when challenged with blood meals from viremic dengue patients. These results suggest that the deployment of superinfections could be used to replace single infections and may represent an effective strategy to help manage potential resistance by DENV to field deployments of single infected strains.

  18. Mosquito larvicidal properties of Impatiens balsamina (Balsaminaceae) against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Marimuthu Govindarajan; Mohan Rajeswary

    2014-01-01

    Objective: To assess the larvicidal potential of the crude benzene, chloroform, ethyl acetate and methanol solvent extracts of the medicinal plant Impatiens balsamina against Anopheles stephensi(An. stephensi), Aedes aegypti (Ae. aegypti) and Culex quinquefasciatus (Cx. quinquefasciatus). Methods: Twenty five third instar larvae of An. stephensi, Ae. aegypti and Cx. quinquefasciatus were exposed to various concentrations and were assayed in the laboratory by using the protocol recommended by WHO. The larval mortality was observed after 24 h of treatment. Results: Among extracts tested, the highest larvicidal activity was observed in leaf methanol extract of Impatiens balsamina against An. stephensi, Ae. aegypti and Cx. quinquefasciatus with the LC50 and LC90 values 98.04, 119.68, 125.06 and 172.93, 210.14, 220.60 mg/L, respectively. Conclusions:From the results it can be concluded that the larvicidal effect of Impatiens balsamina against An. stephensi, Ae. aegypti and Cx. quinquefasciatus make this plant product promising as an alternative to synthetic insecticide in mosquito control programs.

  19. Transmission of Beauveria bassiana from male to female Aedes aegypti mosquitoes

    Directory of Open Access Journals (Sweden)

    Reyes-Villanueva Filiberto

    2011-02-01

    Full Text Available Abstract Background Resistance to chemical insecticides plus high morbidity rates have lead to rising interest in fungi as candidates for biocontrol agents of mosquito vectors. In most studies fungal infections have been induced by exposure of mosquitoes to various surfaces treated with conidia. In the present study eight Mexican strains of Beauveria bassiana were assessed against Aedes aegypti by direct exposure of females to 6 × 108 conidia ml -1 on a filter paper, afterwards, the transmission of the least and most virulent isolates was evaluated by mating behavior from virgin, fungus-contaminated male to females, to examine this ethological pattern as a new approach to deliver conidia against the dengue vector. Methods In an exposure chamber with a filter paper impregnated with 6 × 108 conidia ml -1 of the least and most virulent strains of B. bassiana, 6-8 day old males of A. aegypti were exposed for 48 hours, and then transferred individually (each one was a replicate to another chamber and confined with twenty healthy females of the same age. Clean males were used in controls. Survival, infection by true mating (insemination or by mating attempts (no insemination and fecundity were daily registered until the death of last female. Data analysis was conducted with proc glm for unbalanced experiments and means were separated with the Ryan test with SAS. Results All strains were highly virulent with LT50 ranging from 2.70 (± 0.29 to 5.33 (± 0.53 days. However the most (Bb-CBG2 and least virulent (Bb-CBG4 isolates were also transmitted by mating behavior; both killed 78-90% of females in 15 days after being confined with males that had previously been exposed for 48 hours to fungi. Of these mortality rates, 23 and 38% respectively, were infections acquired by copulations where insemination occurred. The LT50 for sexually-infected females were 7.92 (± 0.46 and 8.82 (± 0.45 days for both strains, while the one in control was 13.92 (± 0

  20. 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.

  1. Evaluation of a peridomestic mosquito trap for integration into an Aedes aegypti (Diptera: Culicidae) push-pull control strategy.

    Science.gov (United States)

    Salazar, Ferdinand V; Achee, Nicole L; Grieco, John P; Prabaripai, Atchariya; Eisen, Lars; Shah, Pankhil; Chareonviriyaphap, Theeraphap

    2012-06-01

    We determined the feasibility of using the BG-Sentinel™ mosquito trap (BGS) as the pull component in a push-pull strategy to reduce indoor biting by Aedes aegypti. This included evaluating varying numbers of traps (1-4) and mosquito release numbers (10, 25, 50, 100, 150, 200, and 250) on recapture rates under screen house conditions. Based on these variations in trap and mosquito numbers, release intervals were rotated through a completely randomized design with environmental factors (temperature, relative humidity, and light intensity) and monitored throughout each experiment. Data from four sampling time points (05:30, 09:30, 13:30, and 17:30) indicate a recapture range among treatments of 66-98%. Furthermore, 2-3 traps were as effective in recapturing mosquitoes as 4 traps for all mosquito release numbers. Time trends indicate Day 1 (the day the mosquitoes were released) as the "impact period" for recapture with peak numbers of marked mosquitoes collected at 09:30 or 4 h post-release. Information from this study will be used to guide the configuration of the BGS trap component of a push-pull vector control strategy currently in the proof-of-concept stage of development in Thailand and Peru.

  2. Nutritional and hormonal regulation of the TOR effector 4E-binding protein (4E-BP) in the mosquito Aedes aegypti

    OpenAIRE

    Roy, Saurabh G.; Raikhel, Alexander S.

    2012-01-01

    Mosquitoes require blood for egg development, and, as a consequence, they transmit pathogens of devastating diseases. Target of rapamycin (TOR) signaling is a key pathway linking blood feeding and egg development in the mosquito Aedes aegypti. We show that the regulation of the TOR effector translational repressor 4E-BP is finely tuned to the nutritional requirements of the female mosquito, and it occurs at transcriptional and post-translational levels. Immediately after blood feeding, 4E-BP ...

  3. 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.

  4. Efectos de la competencia larval en los mosquitos de contenedores artificiales, Aedes aegypti y Culex pipiens (Diptera: Culicidae en condiciones semi-controladas

    Directory of Open Access Journals (Sweden)

    Analía FRANCIA

    2011-01-01

    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 artificiales. 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 (δ estimada según un censo previo de A. aegypti y C. pipiens. Se realizaron 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.

  5. 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.

  6. Mosquito larvicidal activity of Aloe vera (Family: Liliaceae) leaf extract and Bacillus sphaericus, against Chikungunya vector, Aedes aegypti

    Science.gov (United States)

    Subramaniam, Jayapal; Kovendan, Kalimuthu; Mahesh Kumar, Palanisamy; Murugan, Kadarkarai; Walton, William

    2012-01-01

    The bio-efficacy of Aloe vera leaf extract and bacterial insecticide, Bacillus sphaericus larvicidal activity was assessed against the first to fourth instars larvae of Aedes aegypti, under the laboratory conditions. The plant material was shade dried at room temperature and powdered coarsely. A. vera and B. sphaericus show varied degrees of larvicidal activity against various instars larvae of A. aegypti. The LC50 of A. vera against the first to fourth instars larvae were 162.74, 201.43, 253.30 and 300.05 ppm and the LC90 442.98, 518.86, 563.18 and 612.96 ppm, respectively. B. sphaericus against the first to fourth instars larvae the LC50 values were 68.21, 79.13, 93.48, and 107.05 ppm and the LC90 values 149.15, 164.67, 183.84, and 201.09 ppm, respectively. However, the combined treatment of A. vera + B. sphaericus (1:2) material shows highest larvicidal activity of the LC50 values 54.80, 63.11, 74.66 and 95.10 ppm; The LC90 values of 145.29, 160.14, 179.74 and 209.98 ppm, against A. aegypti in all the tested concentrations than the individuals and clearly established that there is a substantial amount of synergist act. The present investigation clearly exhibits that both A. vera and B. sphaericus materials could serve as a potential larvicidal agent. Since, A. aegypti is a container breeder vector mosquito this user and eco-friendly and low-cost vector control strategy could be a viable solution to the existing dengue disease burden. Therefore, this study provides first report on the mosquito larvicidal activity the combined effect of A. vera leaf extract and B. sphaericus against as target species of A. aegypti. PMID:23961212

  7. Comparative mosquito repellency of essential oils against Aedes aegypti (Linn.), Anopheles dirus (Peyton and Harrison) and Culex quinquefasciatus (Say)

    Institute of Scientific and Technical Information of China (English)

    Siriporn Phasomkusolsil; Mayura Soonwera

    2011-01-01

    Objective: To assess the repellency to female Aedes aegypti (Ae. aegypti), Anopheles dirus (An. dirus) and Culex quinquefasciatus (Cx. quinquefasciatus) of seven essential oils using two treatment methods. Methods: Topical applications of three dose concentrations (0.02, 0.10 and 0.21 mg/cm2) were made on the forearms of volunteers. Dose-response study and protection time study were employed in the experiment. Results: In the dose-response test, Cymbopogon citratus (C. citratus), Cymbopogon nardus (C. nardus), Syzygium aromaticum (S. aromaticum) and Ocimum basilicum (O. basilicum) exhibited a high repellency against Ae. aegypti with ED50 at < 0.045 mg/cm2, whereas C. citratus, C. nardus and S. aromaticum showed repellency against An. dirus with ED50 at <0.068 mg/cm2. Furthermore, the essential oils of C. citratus, C. nardus, S. aromaticum, O.basilicum and Cananga odorata gave strong effective dose (ED 50) values at <0.003 mg/cm2 when tested against Cx. quinquefasciatus. For testing by arm in cage method, at 0.21 mg/cm2, protection time of C. citratus gave the longest lasting period against three mosquito species, 72 min for Ae. aegypti, 132 min for An. dirus and 84 min for Cx. quinquefasciatus. In addition, the two essential oils exhibited moderate repellency against Ae. aegypti, An. dirus and Cx. quinquefasciatus, at 60, 90 and 78 min with C. nardus, and 54, 96 and 72 min with S. aromaticum, respectively. Conclusions: The percentage repellency increased when the concentration of essential oils increased. In contrast, biting rates decreased when the concentration of essential oils increased.C. citratus exhibited high efficiency for the protection time and the percentage of biting deterrent against all of 3 mosquito species.

  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. Historical environmental change in Africa drives divergence and admixture of Aedes aegypti mosquitoes: a precursor to successful worldwide colonization?

    Science.gov (United States)

    Bennett, Kelly Louise; Shija, Fortunate; Linton, Yvonne-Marie; Misinzo, Gerald; Kaddumukasa, Martha; Djouaka, Rousseau; Anyaele, Okorie; Harris, Angela; Irish, Seth; Hlaing, Thaung; Prakash, Anil; Lutwama, Julius; Walton, Catherine

    2016-09-01

    Increasing globalization has promoted the spread of exotic species, including disease vectors. Understanding the evolutionary processes involved in such colonizations is both of intrinsic biological interest and important to predict and mitigate future disease risks. The Aedes aegypti mosquito is a major vector of dengue, chikungunya and Zika, the worldwide spread of which has been facilitated by Ae. aegypti's adaption to human-modified environments. Understanding the evolutionary processes involved in this invasion requires characterization of the genetic make-up of the source population(s). The application of approximate Bayesian computation (ABC) to sequence data from four nuclear and one mitochondrial marker revealed that African populations of Ae. aegypti best fit a demographic model of lineage diversification, historical admixture and recent population structuring. As ancestral Ae. aegypti were dependent on forests, this population history is consistent with the effects of forest fragmentation and expansion driven by Pleistocene climatic change. Alternatively, or additionally, historical human movement across the continent may have facilitated their recent spread and mixing. ABC analysis and haplotype networks support earlier inferences of a single out-of-Africa colonization event, while a cline of decreasing genetic diversity indicates that Ae. aegypti moved first from Africa to the Americas and then to Asia. ABC analysis was unable to verify this colonization route, possibly because the genetic signal of admixture obscures the true colonization pathway. By increasing genetic diversity and forming novel allelic combinations, divergence and historical admixture within Africa could have provided the adaptive potential needed for the successful worldwide spread of Ae. aegypti. PMID:27439067

  10. Midgut epithelial responses of different mosquito-Plasmodium combinations: the actin cone zipper repair mechanism in Aedes aegypti.

    Science.gov (United States)

    Gupta, Lalita; Kumar, Sanjeev; Han, Yeon Soo; Pimenta, Paulo F P; Barillas-Mury, Carolina

    2005-03-15

    In vivo responses of midgut epithelial cells to ookinete invasion of three different vector-parasite combinations, Aedes aegypti-Plasmodium gallinaceum, Anopheles stephensi-Plasmodium berghei, and A. stephensi-P. gallinaceum, were directly compared by using enzymatic markers and immunofluorescence stainings. Our studies indicate that, in A. aegypti and A. stephensi ookinetes traverse the midgut via an intracellular route and inflict irreversible damage to the invaded cells. These two mosquito species differ, however, in their mechanisms of epithelial repair. A. stephensi detaches damaged cells by an actin-mediated budding-off mechanism when invaded by either P. berghei or P. gallinaceum. In A. aegypti, the midgut epithelium is repaired by a unique actin cone zipper mechanism that involves the formation of a cone-shaped actin aggregate at the base of the cell that closes sequentially, expelling the cellular contents into the midgut lumen as it brings together healthy neighboring cells. Invasion of A. stephensi by P. berghei induced expression of nitric oxide synthase and peroxidase activities, which mediate tyrosine nitration. These enzymes and nitrotyrosine, however, were not induced in the other two vector-parasite combinations examined. These studies indicate that the epithelial responses of different mosquito-parasite combinations are not universal. The implications of these observations to validate animal experimental systems that reflect the biology of natural vectors of human malarias are discussed. PMID:15753303

  11. Phenotypic and genotypic profile of pyrethroid resistance in populations of the mosquito Aedes aegypti from Goiânia, Central West Brazil

    Directory of Open Access Journals (Sweden)

    Francesca Guaracyaba Garcia Chapadense

    2015-10-01

    Full Text Available ABSTRACTINTRODUCTION:The mosquito Aedes aegypti has evolved resistance to pyrethroid insecticides. The present study evaluated Ae. aegypti from Goiânia for the resistant phenotype and for mutations associated with resistance.METHODS:Insecticide dose-response bioassays were conducted on mosquitoes descended from field-collected eggs, and polymerase chain reaction (PCR was used to genotype 90 individuals at sites implicated in pyrethroid resistance.RESULTS:All mosquito populations displayed high levels of resistance to deltamethrin, as well as high frequencies of the 1016Ile kdr and 1534Cys kdrmutations.CONCLUSIONS:Aedes aegypti populations in the Goiânia area are highly resistant to deltamethrin, presumably due to high frequencies of kdr(knockdown-resistance mutations.

  12. From lab to field: the influence of urban landscapes on the invasive potential of Wolbachia in Brazilian Aedes aegypti mosquitoes.

    Directory of Open Access Journals (Sweden)

    Heverton Leandro Carneiro Dutra

    2015-04-01

    Full Text Available The symbiotic bacterium Wolbachia is currently being trialled as a biocontrol agent in several countries to reduce dengue transmission. Wolbachia can invade and spread to infect all individuals within wild mosquito populations, but requires a high rate of maternal transmission, strong cytoplasmic incompatibility and low fitness costs in the host in order to do so. Additionally, extensive differences in climate, field-release protocols, urbanization level and human density amongst the sites where this bacterium has been deployed have limited comparison and analysis of Wolbachia's invasive potential.We examined key phenotypic effects of the wMel Wolbachia strain in laboratory Aedes aegypti mosquitoes with a Brazilian genetic background to characterize its invasive potential. We show that the wMel strain causes strong cytoplasmic incompatibility, a high rate of maternal transmission and has no evident detrimental effect on host fecundity or fertility. Next, to understand the effects of different urban landscapes on the likelihood of mosquito survival, we performed mark-release-recapture experiments using Wolbachia-uninfected Brazilian mosquitoes in two areas of Rio de Janeiro where Wolbachia will be deployed in the future. We characterized the mosquito populations in relation to the socio-demographic conditions at these sites, and at three other future release areas. We then constructed mathematical models using both the laboratory and field data, and used these to describe the influence of urban environmental conditions on the likelihood that the Wolbachia infection frequency could reach 100% following mosquito release. We predict successful invasion at all five field sites, however the conditions by which this occurs vary greatly between sites, and are strongly influenced by the size of the local mosquito population.Through analysis of laboratory, field and mathematical data, we show that the wMel strain of Wolbachia possesses the characteristics

  13. 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.

  14. Repellent and mosquitocidal effects of leaf extracts of Clausena anisata against the Aedes aegypti mosquito (Diptera: Culicidae).

    Science.gov (United States)

    Mukandiwa, Lillian; Eloff, Jacobus Nicolaas; Naidoo, Vinny

    2016-06-01

    Mosquitoes are rapidly developing resistance to insecticides that millions of people relied on to protect themselves from the diseases they carry, thereby creating a need to develop new insecticides. Clausena anisata is used traditionally as an insect repellent by various communities in Africa and Asia. For this study, the repellency and adulticidal activities of leaf extracts and compounds isolated from this plant species were evaluated against the yellow fever mosquito, Aedes aegypti. In the topical application assays, using total bites as an indicator, repellency was dose dependent, with the acetone crude extract (15 %) having 93 % repellence and the hexane fraction (7.5 %) 67 % repellence after 3 h. Fractionation resulted in a loss of total repellence. As mosquito-net treating agents, the acetone and hexane extracts of C. anisata, both at 15 %, had average repellences of 46.89 ± 2.95 and 50.13 ± 2.02 %, respectively, 3 h after exposure. The C. anisata acetone extract and its hexane fraction caused mosquito knockdown and eventually death when nebulised into the testing chamber, with an EC50 of 78.9 mg/ml (7.89 %) and 71.6 mg/ml (7.16 %) in the first 15 min after spraying. C. anisata leaf extracts have potential to be included in protection products against mosquitoes due to the repellent and cidal compounds contained therein. PMID:26924698

  15. Mosquito larvicidal properties of volatile oil from salt marsh mangrove plant of Sesuvium portulacastrum against Anopheles stephensi and Aedes aegypti

    Institute of Scientific and Technical Information of China (English)

    Mohamed Yacoob Syed Ali; Venkatraman Anuradha; SyedAbudhair Sirajudeen; Prathasarathy Vijaya; Nagarajan Yogananth; Ramachandran Rajan; Peer Mohamed Kalitha Parveen

    2013-01-01

    Objective: To identify the larvicidal activity of the volatile oil from Sesuvium portulacastrum (S.portulacastrum ) against Anopheles stephensi and Aedes aegypti. Methods: Volatile oil extract of S. portulacastrum was prepared in a graded series of concentration. The test for the larvicidal effect of volatile oil against mosquitos larvae was conducted in accordance with the WHO standard method. Batches of 25 early 4th instar larvae of two mosquitoes were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts. Each experiment was conducted with triplicate with concurrent a control group.Results:Volatile oil extract of S. portulacastrum showed toxicity against 4th instar larvae of Aedes aegypti and Anopheles stephensi with equivalent LC50 value [(63±7.8) µL/mL, LCL-UCL=55.2-64.0] and LC90 value [(94.2±3.9) µL/mL)] in maximum activity with minimum concentration (200 µL/mL) of volatile oil and followed by maximum activity of 250 µL concentration showed LC50 value=(68.0±8.2) µL/mL, LCL-UCL=66.26-69.2 and LC50 value of (55.2±2.8) µL/mL, LCL-UCL=53.7-56.9, LC90=(95.2±1.25) µL/mL and followed by 250 µL of oil extract against 4th instar larvae of Aedes aegypti respectively.Conclusions:It is inferred from the present study that, the extracts from salt marsh mangrove plan of S. portulacastum are identified as a potential source of safe and efficacious mosquito control agents for the management of vector borne diseases of malaria and dengue.

  16. Mitochondrial pseudogenes in the nuclear genome of Aedes aegypti mosquitoes: implications for past and future population genetic studies

    Directory of Open Access Journals (Sweden)

    Setha To

    2009-03-01

    Full Text Available Abstract Background Mitochondrial DNA (mtDNA is widely used in population genetic and phylogenetic studies in animals. However, such studies can generate misleading results if the species concerned contain nuclear copies of mtDNA (Numts as these may amplify in addition to, or even instead of, the authentic target mtDNA. The aim of this study was to determine if Numts are present in Aedes aegypti mosquitoes, to characterise any Numts detected, and to assess the utility of using mtDNA for population genetics studies in this species. Results BLAST searches revealed large numbers of Numts in the Ae. aegypti nuclear genome on 146 supercontigs. Although the majority are short (80% Ae. aegypti with ongoing genomic integration, fragmentation and mutation and the secondary movement of Numts within the nuclear genome. The PCR amplification of the putative mtDNA nicotinamide adenine dinucleotide dehydrogenase subunit 4 (ND4 gene from 166 Southeast Asian Ae. aegypti mosquitoes generated a network with two highly divergent lineages (clade 1 and clade 2. Approximately 15% of the ND4 sequences were a composite of those from each clade indicating Numt amplification in addition to, or instead of, mtDNA. Clade 1 was shown to be composed at least partially of Numts by the removal of clade 1-specific bases from composite sequences following enrichment of the mtDNA. It is possible that all the clade 1 sequences in the network were Numts since the clade 2 sequences correspond to the known mitochondrial genome sequence and since all the individuals that produced clade 1 sequences were also found to contain clade 2 mtDNA-like sequences using clade 2-specific primers. However, either or both sets of clade sequences could have Numts since the BLAST searches revealed two long Numts that match clade 2 and one long Numt that matches clade 1. The substantial numbers of mutations in cloned ND4 PCR products also suggest there are both recently-derived clade 1 and clade 2 Numt

  17. 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

  18. The consequences of co-infections for parasite transmission in the mosquito Aedes aegypti.

    Science.gov (United States)

    Duncan, Alison B; Agnew, Philip; Noel, Valérie; Michalakis, Yannis

    2015-03-01

    Co-infections may modify parasite transmission opportunities directly as a consequence of interactions in the within-host environment, but also indirectly through changes in host life history. Furthermore, host and parasite traits are sensitive to the abiotic environment with variable consequences for parasite transmission in co-infections. We investigate how co-infection of the mosquito Aedes aegypti with two microsporidian parasites (Vavraia culicis and Edhazardia aedis) at two levels of larval food availability affects parasite transmission directly, and indirectly through effects on host traits. In a laboratory infection experiment, we compared how co-infection, at low and high larval food availability, affected the probability of infection, within-host growth and the transmission potential of each parasite, compared to single infections. Horizontal transmission was deemed possible for both parasites when infected hosts died harbouring horizontally transmitting spores. Vertical transmission was judged possible for E. aedis when infected females emerged as adults. We also compared the total input number of spores used to seed infections with output number, in single and co-infections for each parasite. The effects of co-infection on parasite fitness were complex, especially for V. culicis. In low larval food conditions, co-infection increased the chances of mosquitoes dying as larvae or pupae, thus increasing opportunities for V. culicis' horizontal transmission. However, co-infection reduced larval longevity and hence time available for V. culicis spore production. Overall, there was a negative net effect of co-infection on V. culicis, whereby the number of spores produced was less than the number used to seed infection. Co-infections also negatively affected horizontal transmission of the more virulent parasite, E. aedis, through reduced longevity of pre-adult hosts. However, its potential transmission suffered less relative to V. culicis. Our results

  19. Pharmacological and Genetic Evidence for Gap Junctions as Potential New Insecticide Targets in the Yellow Fever Mosquito, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Travis L Calkins

    Full Text Available The yellow fever mosquito Aedes aegypti is an important vector of viral diseases that impact global health. Insecticides are typically used to manage mosquito populations, but the evolution of insecticide resistance is limiting their effectiveness. Thus, identifying new molecular and physiological targets in mosquitoes is needed to facilitate insecticide discovery and development. Here we test the hypothesis that gap junctions are valid molecular and physiological targets for new insecticides. Gap junctions are intercellular channels that mediate direct communication between neighboring cells and consist of evolutionarily distinct proteins in vertebrate (connexins and invertebrate (innexins animals. We show that the injection of pharmacological inhibitors of gap junctions (i.e., carbenoxolone, meclofenamic acid, or mefloquine into the hemolymph of adult female mosquitoes elicits dose-dependent toxic effects, with mefloquine showing the greatest potency. In contrast, when applied topically to the cuticle, carbenoxolone was the only inhibitor to exhibit full efficacy. In vivo urine excretion assays demonstrate that both carbenoxolone and mefloquine inhibit the diuretic output of adult female mosquitoes, suggesting inhibition of excretory functions as part of their mechanism of action. When added to the rearing water of 1st instar larvae, carbenoxolone and meclofenamic acid both elicit dose-dependent toxic effects, with meclofenamic acid showing the greatest potency. Injecting a double-stranded RNA cocktail against innexins into the hemolymph of adult female mosquitoes knock down whole-animal innexin mRNA expression and decreases survival of the mosquitoes. Taken together these data indicate that gap junctions may provide novel molecular and physiological targets for the development of insecticides.

  20. Pharmacological and Genetic Evidence for Gap Junctions as Potential New Insecticide Targets in the Yellow Fever Mosquito, Aedes aegypti.

    Science.gov (United States)

    Calkins, Travis L; Piermarini, Peter M

    2015-01-01

    The yellow fever mosquito Aedes aegypti is an important vector of viral diseases that impact global health. Insecticides are typically used to manage mosquito populations, but the evolution of insecticide resistance is limiting their effectiveness. Thus, identifying new molecular and physiological targets in mosquitoes is needed to facilitate insecticide discovery and development. Here we test the hypothesis that gap junctions are valid molecular and physiological targets for new insecticides. Gap junctions are intercellular channels that mediate direct communication between neighboring cells and consist of evolutionarily distinct proteins in vertebrate (connexins) and invertebrate (innexins) animals. We show that the injection of pharmacological inhibitors of gap junctions (i.e., carbenoxolone, meclofenamic acid, or mefloquine) into the hemolymph of adult female mosquitoes elicits dose-dependent toxic effects, with mefloquine showing the greatest potency. In contrast, when applied topically to the cuticle, carbenoxolone was the only inhibitor to exhibit full efficacy. In vivo urine excretion assays demonstrate that both carbenoxolone and mefloquine inhibit the diuretic output of adult female mosquitoes, suggesting inhibition of excretory functions as part of their mechanism of action. When added to the rearing water of 1st instar larvae, carbenoxolone and meclofenamic acid both elicit dose-dependent toxic effects, with meclofenamic acid showing the greatest potency. Injecting a double-stranded RNA cocktail against innexins into the hemolymph of adult female mosquitoes knock down whole-animal innexin mRNA expression and decreases survival of the mosquitoes. Taken together these data indicate that gap junctions may provide novel molecular and physiological targets for the development of insecticides.

  1. Analyses of essential and edible oils, and constituents therein, as candidate repellents for the yellow fever mosquito Aedes aegypti L. (Diptera: Culicidae)

    OpenAIRE

    Campbell, Cory James

    2009-01-01

    Some plant essential and edible oils repel mosquitoes but often quantitatively minor repellent constituents therein remain unknown. In gas chromatographic-electroantennographic detection (GC-EAD) analyses of catnip, cinnamon, citronella, cumin, eucalyptus, geranium, ginger, melissa, peppermint, rosemary, and thyme essential oils, 43 constituents elicited responses from antennae of female yellow fever mosquitoes, Aedes aegypti L. (Diptera: Culicidae). GC-EAD analyses of soybean oil (active ing...

  2. 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.

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

    Institute of Scientific and Technical Information of China (English)

    K Kovendan; K Murugan; S Vincent; Donald R Barnard

    2012-01-01

    ABSTRACT Objective:To determine the mosquito larvicidal activities of hexane, chloroform, ethyl acetate, acetone and methanol leaf extract ofOrthosiphon thymiflorus (O. thymiflorus) againstAnopheles stephensi (An. stephensi), Culex quinquefasciatus (Cx. quinquefasciatus) andAedes aegypti (Ae. aegypti).Methods: The larvicidal activity was assayed against three mosquito species at various concentrations ranging from (50-450 ppm) under the laboratory conditions. TheLC50and LC90value of theO. thymiflorus leaf extract was determined by Probit analysis.Results: The LC50values of hexane, chloroform, ethyl acetate, acetone and methanol extract ofO. thymiflorus third instar larvae ofAn. stephensiwereLC50= 201.39, 178.76, 158.06, 139.22 and118.74 ppm;Cx. quinquefasciatus were LC50=228.13, 209.72, 183.35, 163.55 and149.96 ppm andAe. aegyptiwere LC50=215.65, 197.91, 175.05, 154.80 and137.26 ppm, respectively. Maximum larvicidal activity was observed in the methanolic extract followed by acetone, ethyl acetate chloroform and hexane extract. The larval mortality was observed after24h exposure. No mortality was observed in control.Conclusions:The present results suggest that the effective plant crude extracts have potential to be used as an ideal eco-friendly approach for the control of mosquito vectors. This study provides the first report on the larvicidal activity of this plant crude solvent extract of againstAn. stephensi, Cx. quinquefasciatus andAe. aegyptimosquitoes.

  4. 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.

  5. Host and viral features of human dengue cases shape the population of infected and infectious Aedes aegypti mosquitoes

    Science.gov (United States)

    Nguyen, Nguyet Minh; Thi Hue Kien, Duong; Tuan, Trung Vu; Quyen, Nguyen Than Ha; Tran, Chau N. B.; Vo Thi, Long; Thi, Dui Le; Nguyen, Hoa Lan; Farrar, Jeremy J.; Holmes, Edward C.; Rabaa, Maia A.; Bryant, Juliet E.; Nguyen, Truong Thanh; Nguyen, Huong Thi Cam; Nguyen, Lan Thi Hong; Pham, Mai Phuong; Nguyen, Hung The; Luong, Tai Thi Hue; Wills, Bridget; Nguyen, Chau Van Vinh; Wolbers, Marcel; Simmons, Cameron P.

    2013-01-01

    Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (n = 208) to Aedes aegypti mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1–4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission. PMID:23674683

  6. 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

    2015-09-01

    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.

  7. Identification of a major Quantitative Trait Locus determining resistance to the organophosphate temephos in the dengue vector mosquito Aedes aegypti.

    Science.gov (United States)

    Paiva, Marcelo H S; Lovin, Diane D; Mori, Akio; Melo-Santos, Maria A V; Severson, David W; Ayres, Constância F J

    2016-01-01

    Organophosphate insecticides (OP) have extensively been used to control mosquitoes, such as the vector Aedes aegypti. Unfortunately, OP resistance has hampered control programs worldwide. We used Quantitative Trait Locus (QTL) mapping to evaluate temephos resistance in two F1 intercross populations derived from crosses between a resistant Ae. aegypti strain (RecR) and two susceptible strains (MoyoD and Red). A single major effect QTL was identified on chromosome 2 of both segregating populations, named rtt1 (resistance to temephos 1). Bioinformatics analyses identified a cluster of carboxylesterase genes (CCE) within the rtt1 interval. qRT-PCR demonstrated that different CCEs were up-regulated in F2 resistant individuals from both crosses. However, none exceeded the 2-fold expression. Primary mechanisms for temephos resistance may vary between Ae. aegypti populations, yet also appear to support previous findings suggesting that multiple linked esterase genes may contribute to temephos resistance in the RecR strain as well as other populations. PMID:26576515

  8. Human impacts have shaped historical and recent evolution in Aedes aegypti, the dengue and yellow fever mosquito.

    Science.gov (United States)

    Brown, Julia E; Evans, Benjamin R; Zheng, Wei; Obas, Vanessa; Barrera-Martinez, Laura; Egizi, Andrea; Zhao, Hongyu; Caccone, Adalgisa; Powell, Jeffrey R

    2014-02-01

    Although anthropogenic impacts are often considered harmful to species, human modifications to the landscape can actually create novel niches to which other species can adapt. These "domestication" processes are especially important in the context of arthropod disease vectors, where ecological overlap of vector and human populations may lead to epidemics. Here, we present results of a global genetic study of one such species, the dengue and yellow fever mosquito, Aedes aegypti, whose evolutionary history and current distribution have been profoundly shaped by humans. We used DNA sequences of four nuclear genes and 1504 single nucleotide polymorphism (SNP) markers developed with restriction-site associated DNA (RAD) sequencing to test the hypothesis that Ae. aegypti originated in Africa, where a domestic form arose and spread throughout the tropical and subtropical world with human trade and movement. Results confirmed African ancestry of the species, and supported a single subspeciation event leading to the pantropical domestic form. In addition, genetic data strongly supported the hypothesis that human trade routes first moved domestic Ae. aegypti out of Africa into the New World, followed by a later invasion from the New World into Southeast Asia and the Pacific. These patterns of domestication and invasion are relevant to many species worldwide, as anthropogenic forces increasingly impact evolutionary processes. PMID:24111703

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

    Directory of Open Access Journals (Sweden)

    Konstantin A Tsetsarkin

    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

  10. microRNA-309 targets the Homeobox gene SIX4 and controls ovarian development in the mosquito Aedes aegypti.

    Science.gov (United States)

    Zhang, Yang; Zhao, Bo; Roy, Sourav; Saha, Tusar T; Kokoza, Vladimir A; Li, Ming; Raikhel, Alexander S

    2016-08-16

    Obligatory blood-triggered reproductive strategy is an evolutionary adaptation of mosquitoes for rapid egg development. It contributes to the vectorial capacity of these insects. Therefore, understanding the molecular mechanisms underlying reproductive processes is of particular importance. Here, we report that microRNA-309 (miR-309) plays a critical role in mosquito reproduction. A spatiotemporal expression profile of miR-309 displayed its blood feeding-dependent onset and ovary-specific manifestation in female Aedes aegypti mosquitoes. Antagomir silencing of miR-309 impaired ovarian development and resulted in nonsynchronized follicle growth. Furthermore, the genetic disruption of miR-309 by CRISPR/Cas9 system led to the developmental failure of primary follicle formation. Examination of genomic responses to miR-309 depletion revealed that several pathways associated with ovarian development are down-regulated. Comparative analysis of genes obtained from the high-throughput RNA sequencing of ovarian tissue from the miR-309 antagomir-silenced mosquitoes with those from the in silico computation target prediction identified that the gene-encoding SIX homeobox 4 protein (SIX4) is a putative target of miR-309. Reporter assay and RNA immunoprecipitation confirmed that SIX4 is a direct target of miR-309. RNA interference of SIX4 was able to rescue phenotypic manifestations caused by miR-309 depletion. Thus, miR-309 plays a critical role in mosquito reproduction by targeting SIX4 in the ovary and serves as a regulatory switch permitting a stage-specific degradation of the ovarian SIX4 mRNA. In turn, this microRNA (miRNA)-targeted degradation is required for appropriate initiation of a blood feeding-triggered phase of ovarian development, highlighting involvement of this miRNA in mosquito reproduction. PMID:27489347

  11. Diminished reproductive fitness associated with the deltamethrin resistance in an Indian strain of dengue vector mosquito, Aedes aegypti L.

    Science.gov (United States)

    Kumar, Sarita; Thomas, Anita; Samuel, Thomas; Sahgal, Arunima; Verma, Anita; Pillai, M K K

    2009-08-01

    The susceptible (SS) and resistant (DLR) strains of Aedes aegypti selected with deltamethrin and combination of deltamethrin and PBO (1:5) at the larval/adult stage were studied in the laboratory for their reproductive fitness in terms of fecundity, hatchability and longevity of gonotrophic cycles. The DLR strains exhibited 73-88% reduction in the duration of gonotrophic cycles as compared to their SS counterparts. There was a considerable decrease in egg production and hatchability rates in the selected strains of Ae. aegypti, as compared to that of the SS strain. Data indicate deltamethrin being an effective insecticide against Ae. aegypti and a possible correlation between the deltamethrin resistance and disadvantages during reproduction. The most drastic and significant effect was observed in DLR1b strains exhibiting 36.7% decrease in fecundity and 32.4% reduction in hatchability. Another important observation was diminished reproductive fitness in DLR2 strains. This suggests the usefulness of synergized deltamethrin selections in reducing the frequency of resistant individuals. A significant finding was to observe the reproductive disadvantage in adult-selected strains having negligible resistance to deltamethrin implicating the efficacy of deltamethrin as an adulticide rather than as a larvicide. Various probable reasons for the reduction in the reproductive potential and the possible resistance-management strategies of Ae. aegypti are discussed. PMID:19901902

  12. Characterizing the Aedes aegypti population in a Vietnamese village in preparation for a Wolbachia-based mosquito control strategy to eliminate dengue.

    Directory of Open Access Journals (Sweden)

    Jason A L Jeffery

    Full Text Available BACKGROUND: A life-shortening strain of the obligate intracellular bacteria Wolbachia, called wMelPop, is seen as a promising new tool for the control of Aedes aegypti. However, developing a vector control strategy based on the release of mosquitoes transinfected with wMelPop requires detailed knowledge of the demographics of the target population. METHODOLOGY/PRINCIPAL FINDINGS: In Tri Nguyen village (611 households on Hon Mieu Island in central Vietnam, we conducted nine quantitative entomologic surveys over 14 months to determine if Ae. aegypti populations were spatially and temporally homogenous, and to estimate population size. There was no obvious relationship between mosquito (larval, pupal or adult abundance and temperature and rainfall, and no area of the village supported consistently high numbers of mosquitoes. In almost all surveys, key premises produced high numbers of Ae. aegypti. However, these premises were not consistent between surveys. For an intervention based on a single release of wMelPop-infected Ae. aegypti, release ratios of infected to uninfected adult mosquitoes of all age classes are estimated to be 1.8-6.7ratio1 for gravid females (and similarly aged males or teneral adults, respectively. We calculated that adult female mosquito abundance in Tri Nguyen village could range from 1.1 to 43.3 individuals of all age classes per house. Thus, an intervention could require the release of 2-78 wMelPop-infected gravid females and similarly aged males per house, or 7-290 infected teneral female and male mosquitoes per house. CONCLUSIONS/SIGNIFICANCE: Given the variability we encountered, this study highlights the importance of multiple entomologic surveys when evaluating the spatial structure of a vector population or estimating population size. If a single release of wMelPop-infected Ae. aegypti were to occur when wild Ae. aegypti abundance was at its maximum, a preintervention control program would be necessary to ensure that

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

    Directory of Open Access Journals (Sweden)

    Michal Segoli

    2014-12-01

    Full Text Available 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.

  14. Deltamethrin-mediated survival, behavior, and oenocyte morphology of insecticide-susceptible and resistant yellow fever mosquitos (Aedes aegypti).

    Science.gov (United States)

    Marriel, Nadja Biondine; Tomé, Hudson Vaner Ventura; Guedes, Raul Carvalho Narciso; Martins, Gustavo Ferreira

    2016-06-01

    Insecticide use is the prevailing control tactic for the mosquito Aedes aegypti, a vector of several human viruses, which leads to ever-increasing problems of insecticide resistance in populations of this insect pest species. The underlying mechanisms of insecticide resistance may be linked to the metabolism of insecticides by various cells, including oenocytes. Oenocytes are ectodermal cells responsible for lipid metabolism and detoxification. The goal of this study was to evaluate the sublethal effects of deltamethrin on survival, behavior, and oenocyte structure in the immature mosquitoes of insecticide-susceptible and resistant strains of A. aegypti. Fourth instar larvae (L4) of both strains were exposed to different concentrations of deltamethrin (i.e., 0.001, 0.003, 0.005, and 0.007 ppm). After exposure, L4 were subjected to behavioral bioassays. Insecticide effects on cell integrity after deltamethrin exposure (at 0.003 or 0.005 ppm) were assessed by processing pupal oenocytes for transmission electron microscopy or TUNEL reaction. The insecticide resistant L4 survived all the tested concentrations, whereas the 0.007-ppm deltamethrin concentration had lethal effects on susceptible L4. Susceptible L4 were lethargic and exhibited less swimming activity than unexposed larvae, whereas the resistant L4 were hyperexcited following exposure to 0.005 ppm deltamethrin. No sublethal effects and no significant cell death were observed in the oenocytes of either susceptible or resistant insects exposed to deltamethrin. The present study illustrated the different responses of susceptible and resistant strains of A. aegypti following exposure to sublethal concentration of deltamethrin, and demonstrated how the behavior of the immature stage of the two strains varied, as well as oenocyte structure following insecticide exposure. PMID:26943998

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

    Science.gov (United States)

    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. PMID:27530057

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

    Science.gov (United States)

    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. PMID:25630696

  17. Apoptosis-related genes control autophagy and influence DENV-2 infection in the mosquito vector, Aedes aegypti.

    Science.gov (United States)

    Eng, Matthew W; van Zuylen, Madeleine N; Severson, David W

    2016-09-01

    The mosquito Aedes aegypti is the primary urban vector for dengue virus (DENV) worldwide. Insight into interactions occurring between host and pathogen is important in understanding what factors contribute to vector competence. However, many of the molecular mechanisms for vector competence remain unknown. Our previous global transcriptional analysis suggested that differential expression of apoptotic proteins is involved in determining refractoriness vs susceptibility to DENV-2 infection in Ae. aegypti females following a DENV-infected blood meal. To determine whether DENV-refractory Ae. aegypti showed more robust apoptosis upon infection, we compared numbers of apoptotic cells from midguts of refractory and susceptible strains and observed increased numbers of apoptotic cells in only the refractory strain upon DENV-2 infection. Thereafter, we manipulated apoptosis through dsRNA interference of the initiator caspase, Aedronc. Unexpectedly, dsAedronc-treated females showed both decreased frequency of disseminated infection and decreased virus titer in infected individuals. Insect caspases have also previously been identified as regulators of the cellular recycling process known as autophagy. We observed activation of autophagy in midgut and fat body tissues following a blood meal, as well as programmed activation of several apoptosis-related genes, including the effector caspase, Casps7. To determine whether autophagy was affected by caspase knockdown, we silenced Aedronc and Casps7, and observed reduced activation of autophagy upon silencing. Our results provide evidence that apoptosis-related genes are also involved in regulating autophagy, and that Aedronc may play an important role in DENV-2 infection success in Ae. aegypti, possibly through its regulation of autophagy. PMID:27418459

  18. Distinct sets of PIWI proteins produce arbovirus and transposon-derived piRNAs in Aedes aegypti mosquito cells.

    Science.gov (United States)

    Miesen, Pascal; Girardi, Erika; van Rij, Ronald P

    2015-07-27

    The PIWI-interacting RNA (piRNA) pathway is essential for transposon silencing in many model organisms. Its remarkable efficiency relies on a sophisticated amplification mechanism known as the ping-pong loop. In Alphavirus-infected Aedes mosquitoes, piRNAs with sequence features that suggest ping-pong-dependent biogenesis are produced from viral RNA. The PIWI family in Aedes mosquitoes is expanded when compared to other model organisms, raising the possibility that individual PIWI proteins have functionally diversified in these insects. Here, we show that Piwi5 and Ago3, but none of the other PIWI family members, are essential for piRNA biogenesis from Sindbis virus RNA in infected Aedes aegypti cells. In contrast, the production of piRNAs from transposons relies on a more versatile set of PIWI proteins, some of which do not contribute to viral piRNA biogenesis. These results indicate that functional specialization allows distinct mosquito PIWI proteins to process RNA from different endogenous and exogenous sources.

  19. Surveillance of Aedes aegypti (L. Mosquitoes in Mumbai International Seaport (India to Monitor Potential Global Health Risks

    Directory of Open Access Journals (Sweden)

    Kaushal Kumar

    2014-01-01

    Full Text Available Aedes mosquitoes are highly invasive and can survive almost any climatic conditions. They transmit a number of major world's deadly diseases. Therefore, a study was undertaken during December 2010 to evaluate the entomo-epidemiological risk of Aedes mosquito borne diseases (VBD in Mumbai international seaport areas to minimize potential global health risks and prevent introduction of new VBD in India. Surveys were undertaken in operational and residential areas of Mumbai Port Trust (MPT. All the entomological indices were found to be above the critical level, prescribed for seaports by International Health Regulations Act, 2005. The operational areas where large goods are handled from cargo ships were found to be more prone to mosquito breeding comparing to residential areas. High insecticide tolerance of Aedes aegypti population against temephos and fenthion from Mumbai port area is reported for the first time. A careful and regular invigilation of the international seaports to prevent building up of vector density of dengue/chikungunya and yellow fever is recommended.

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

    Directory of Open Access Journals (Sweden)

    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

  1. An optimal control model of mosquito reduction management in a dengue endemic region

    OpenAIRE

    Wijaya, Karunia Putra; Goetz, Thomas; Soewono, Edy

    2015-01-01

    Aedes aegypti is known as the responsible vector in transmitting dengue flavivirus. Unavailability of medication to cure the transmission in human blood becomes a global health issue in recent decades. World epidemiologists are encouraged to focus on inves- tigation toward an effective and inexpensive way to prevent dengue transmission, i.e. mosquito control. In this paper, we present a model depicting the dynamics of mosquito population based on indoor-outdoor life cycle classification. The ...

  2. Gravid females of the mosquito Aedes aegypti avoid oviposition on m-cresol in the presence of the deterrent isomer p-cresol

    OpenAIRE

    Afify, Ali; Galizia, Giovanni

    2014-01-01

    Background p-cresol (4-methylphenol) and its isomer m-cresol (3-methylphenol) have been shown to activate the same sensilla in Aedes aegypti (Linnaeus) mosquitoes. Whereas p-cresol has been suggested to play a role in oviposition site choice, the behavioral significance of m-cresol is unknown. Methods Here, we assayed the oviposition behavior of Aedes aegypti towards p-cresol and m-cresol using cage assay. Specifically we tested different concentrations of p-cresol (10-12-103 ppm) and m-creso...

  3. 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

    Directory of Open Access Journals (Sweden)

    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

  4. Infection with a Virulent Strain of Wolbachia Disrupts Genome Wide-Patterns of Cytosine Methylation in the Mosquito Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Yixin H Ye

    Full Text Available Cytosine methylation is one of several reversible epigenetic modifications of DNA that allow a greater flexibility in the relationship between genotype and phenotype. Methylation in the simplest models dampens gene expression by modifying regions of DNA critical for transcription factor binding. The capacity to methylate DNA is variable in the insects due to diverse histories of gene loss and duplication of DNA methylases. Mosquitoes like Drosophila melanogaster possess only a single methylase, DNMT2.Here we characterise the methylome of the mosquito Aedes aegypti and examine its relationship to transcription and test the effects of infection with a virulent strain of the endosymbiont Wolbachia on the stability of methylation patterns.We see that methylation in the A. aegypti genome is associated with reduced transcription and is most common in the promoters of genes relating to regulation of transcription and metabolism. Similar gene classes are also methylated in aphids and honeybees, suggesting either conservation or convergence of methylation patterns. In addition to this evidence of evolutionary stability, we also show that infection with the virulent wMelPop Wolbachia strain induces additional methylation and demethylation events in the genome. While most of these changes seem random with respect to gene function and have no detected effect on transcription, there does appear to be enrichment of genes associated with membrane function. Given that Wolbachia lives within a membrane-bound vacuole of host origin and retains a large number of genes for transporting host amino acids, inorganic ions and ATP despite a severely reduced genome, these changes might represent an evolved strategy for manipulating the host environments for its own gain. Testing for a direct link between these methylation changes and expression, however, will require study across a broader range of developmental stages and tissues with methods that detect splice variants.

  5. Insecticidal potential of Ocimum canum plant extracts against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus larval and adult mosquitoes (Diptera: Culicidae).

    Science.gov (United States)

    Murugan, Jimmantiyur Madhappan; Ramkumar, Govindaraju; Shivakumar, Muthugoundar Subramanian

    2016-01-01

    Mosquitoes have developed resistance to various synthetic insecticides, making their control increasingly difficult. Insecticides of botanical origin may serve as suitable natural control. This study evaluates the toxic potential of Ocimum canum (Sims) leaf extract and powder against Anopheles stephensi (Liston), Aedes aegypti (Lin) and Culex quinquefasciatus (Say) larval and adult mosquitoes. Larval mortality was observed after 24 h recovery period and adult smoke toxicity observed for 40 min duration at 10 min interval. Methanol extract of O. canum showed highest larval mortality against the larvae of C. quinquefasciatus LC50 = 28.3225, LC90 = 44.1150; Ae. aegypti LC50 = 43.327, LC90 = 61.249; and An. stephensi LC50 = 30.2001, LC90 = 48.2866 ppm. The smoke toxicities were 93% mortality in C. quinquefasciatus, 74% in Ae. aegypti and 79% in An. stephensi adults, respectively, whereas 100% mortality was recorded in the commercial mosquito control. Our results suggest that O. canum leaf extract and powder are natural insecticide, and ideal eco friendly approach for mosquito control.

  6. Temporal genetic stability of Stegomyia aegypti (= Aedes aegypti) populations.

    Science.gov (United States)

    Gloria-Soria, A; Kellner, D A; Brown, J E; Gonzalez-Acosta, C; Kamgang, B; Lutwama, J; Powell, J R

    2016-06-01

    The mosquito Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is the primary vector of viruses that cause yellow fever, dengue and Chikungunya fever. In the absence of effective vaccines, the reduction of these diseases relies on vector control strategies. The success of these strategies is tightly linked to the population dynamics of target populations. In the present study, 14 collections from St. aegypti populations separated by periods of 1-13 years were analysed to determine their temporal genetic stability. Although temporal structure is discernible in most populations, the degree of temporal differentiation is dependent on the population and does not obscure the geographic structure of the various populations. The results suggest that performing detailed studies in the years prior to and after population reduction- or modification-based control interventions at each target field site may be useful in assessing the probability of success. PMID:26744174

  7. 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

    OpenAIRE

    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

    2015-01-01

    Background 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. Methods 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 control...

  8. 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

    OpenAIRE

    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

    2015-01-01

    BACKGROUND: 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. METHODS: 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 co...

  9. Modelling Aedes aegypti mosquito control via transgenic and sterile insect techniques: endemics and emerging outbreaks

    OpenAIRE

    Seirin Lee, S.; Baker, R. E.; Gaffney, E.A.; White, S. M.

    2013-01-01

    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 pestresistance still remain,and mosquito-borne diseases such as malaria and dengue fever prevail in many countries,infecting over100 million worldwide in 2010.One environmentally friendly method for mosquito control is the Sterile...

  10. Identification and characterization of juvenile hormone esterase gene from the yellow fever mosquito, Aedes aegypti

    OpenAIRE

    Bai, Hua; Ramaseshadri, Parthasarathy; Palli, Subba Reddy

    2007-01-01

    Juvenile hormone esterase (JHE) plays an important role in regulating juvenile hormone titers. Recent sequencing and annotation of the Aedes aegypti genome identified ten putative jhe gene sequences. Analysis of these ten putative jhe gene sequences showed that only three of them, EAT43357, EAT43353 and EAT43354 contained GQSAG motif and showed high sequence similarity with the sequences of jhe genes identified from other insect species. To determine which putative jhe gene(s) code for functi...

  11. 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.

  12. 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

    OpenAIRE

    Mariana Rocha David; Ricardo Lourenço-de-Oliveira; Rafael Maciel de Freitas

    2009-01-01

    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 identifi...

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

    Directory of Open Access Journals (Sweden)

    Alan J Grant

    Full Text Available BACKGROUND: 1-Octen-3-ol (octenol is a common attractant released by vertebrates which in combination with carbon dioxide (CO(2 attracts hematophagous arthropods including mosquitoes. A receptor neuron contained within basiconic sensilla on the maxillary palps of adult mosquitoes responds selectively to 1-octen-3-ol. Recently, an odorant receptor (AaegOR8 known to occur on the maxillary palps was expressed in a heterologous system and demonstrated to be selectively sensitive to (R-(--1-octen-3-ol, one of two enantiomeric forms. Lesser responses were elicited by stimulation with the (S-enantiomer and various structural analogs. METHODOLOGY/PRINCIPAL FINDINGS: Here we characterize the specificity of the octenol receptor neuron in the yellow fever mosquito, Aedes aegypti (L., in vivo using single cell recordings. The octenol neuron is exquisitely sensitive to (R-(--1-octen-3-ol; comparable responses to (S-(+-1-octen-3-ol were elicited only at stimulus doses over 100× that required for the (R-enantiomer. An intermediate response closer to that elicited by the (R-(--enantiomer was elicited by racemic 1-octen-3-ol. Small structural changes in (R-(--1-octen-3-ol resulted in large decreases in responses. Increases in spike activity were also elicited in the octenol neuron by 2-undecanone, a known repellent; other repellents (DEET, IR3535 and picaridin were inactive. CONCLUSIONS/SIGNIFICANCE: The results of our electrophysiological studies of the octenol receptor neuron in vivo approximates results of a previous study of the octenol receptor (AaegOR8 with its obligate partner Aaeg\\ORco expressed heterologously in Xenopus oocytes. By comparison of our current results with those of the heterologous expression study, we conclude that specificity of the octenol receptor neuron can be explained largely by characteristics of the OR alone without other associated proteins present in vivo. Our findings show that repellents may have specific stimulatory effects

  14. Defining the core apoptosis pathway in the mosquito disease vector Aedes aegypti: the roles of iap1, ark, dronc, and effector caspases.

    Science.gov (United States)

    Liu, Qingzhen; Clem, Rollie J

    2011-02-01

    To date, our knowledge of apoptosis regulation in insects comes almost exclusively from the model organism Drosophila melanogaster. In contrast, despite the identification of numerous genes that are presumed to regulate apoptosis in other insects based on sequence homology, little has been done to examine the molecular pathways that regulate apoptosis in other insects, including medically important disease vectors. In D. melanogaster, the core apoptosis pathway consists of the caspase negative regulator DIAP1, IAP antagonists, the initiator caspase Dronc and its activating protein Ark, and the effector caspase DrICE. Here we have studied the functions of several genes from the mosquito disease vector Aedes aegypti that share homology with the core apoptosis genes in D. melanogaster. Silencing of the iap1 gene in the A. aegypti cell line Aag2 caused spontaneous apoptosis, indicating that IAP1 plays a role in cell survival similar to that of DIAP1. Silencing A. aegypti ark or dronc completely inhibited apoptosis triggered by several different apoptotic stimuli. However, individual silencing of the effector caspases CASPS7 or CASPS8, which are the closest relatives to DrICE, only partially inhibited apoptosis, and silencing both CASPS7 and CASPS8 together did not have a significant additional effect. Our results suggest that the core pathway that regulates apoptosis in A. aegypti is similar to that of D. melanogaster, but that more than one effector caspase is involved in apoptosis in A. aegypti. This is interesting in light of the fact that the caspase family has expanded in mosquitoes compared to D. melanogaster.

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

    Institute of Scientific and Technical Information of China (English)

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

    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. 32109 larvae representing 1st , 2nd, 3rd, and 4th stages were collected from 22618 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.

  16. 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

  17. Bioefficacy of Mentha piperita essential oil against dengue fever mosquito Aedes aegypti L

    Directory of Open Access Journals (Sweden)

    Sarita Kumar

    2011-04-01

    Conclusions: The peppermint essential oil is proved to be efficient larvicide and repellent against dengue vector. Further studies are needed to identify the possible role of oil as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the oil could help in formulating strategies for mosquito control.

  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. Lantana montevidensis Essential Oil: Chemical Composition and Mosquito Repellent Activity against Aedes aegypti

    Science.gov (United States)

    The essential oil (EO) of Lantana montevidensis (Spreng.) Briq. (L. sellowiana Link & Otto) was investigated for its chemical composition and mosquito repellent activity. The essential oil obtained by hydrodistillation of aerial plant parts was analyzed by GC-FID and GC-MS. The major constituents we...

  20. Determination and characterization of destruxin production in Metarhizium anisopliae Tk6 and formulations for Aedes aegypti mosquitoes control at the field level.

    Science.gov (United States)

    Ravindran, Keppanan; Akutse, Komivi Senyo; Sivaramakrishnan, Sivaperumal; Wang, Liande

    2016-09-15

    Destruxins, cyclic hexadepsipeptide toxins, secreted by the entomopathogenic fungus, Metarhizium anisopliae through extracellular synthesis. The present study reports a new approach for the analysis of DTXs produced by the fungal strain Metarhizium anisoliae Tk6, using FRIR-HPLC-LC-MS and H(1) NMR. The results also showed that production of the major DTXs A, B, C, and E have to be determined in Czapek Dextrose (CD) liquid culture filtrate from 9 to 12 days post-inoculation. Purified DTX were further tested in bioassays to assess their effects of Aedes aegypti mosquitoes. The four major purified DTX compounds were found to cause a toxic effect on the larval developmental stages of mosquitoes with high mortality rates. However, DTX E outperformed the other three DTXs by causing the highest mortality three days after inoculation. This result gives an alternative approach of using DTXs in mosquitoes control and used as a new method for other pest management. PMID:27452930

  1. 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.

  2. Bioactivity of seagrass against the dengue fever mosquito Aedes aegypti larvae

    Institute of Scientific and Technical Information of China (English)

    M Syed Ali; S Ravikumar; J Margaret Beula

    2012-01-01

    Objective: To identify the larvicidal activity of the seagrass extracts. Methods: Seagrass extracts, Syringodium isoetifolium (S. isoetifolium), Cymodocea serrulata and Halophila beccarii, were dissolved in DMSO to prepare a graded series of concentration. Batches of 25 early 4th instars larvae of Aedes aegypti (Ae. aegypti) were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (0.01 mg–0.1 mg). After 24 h the mortality rate was identified with the formulae [(%of test mortality- %of control mortality)/(100- %of control mortality)]í100. Each experiment was conducted with three replicates and a concurrent control group. A control group consisted of 1 mL of DMSO and 199 mL of distilled water only. Results:The root extract of S. isoetifolium showed maximum larvicidal activity with minimum concentration of extract of LC50= 0.0 604± 0.0 040)μg/mL with lower confidence limit (LCL)-upper confidence limit (UCL)=(0.051-0.071) and LC90=0.0 972μg/mL followed by leaf extract of S. isoetifolium showed LC50= (0.062± 0.005)μg/mL. The regression equation of root and leaf extract of S. isoetifolium for 4th instar larvae were Y=4.909+1.32x (R2=0.909) and Y=2.066+1.21x (R2=0.897) respectively. The results of the preliminary phytochemical constituents shows the presence of saponin, steroids, terpenoid, phenols, protein and sugars. Conclusions: From the present study the ethanolic extracts of seagrass of S. isoetifolium possesses lead compound for development of larvicidal activity.

  3. 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.

  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. PMID:26410042

  5. 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.

  6. Larvicidal efficacy of different plant parts of railway creeper, Ipomoea cairica Extract Against Dengue Vector Mosquitoes, Aedes albopictus (Diptera: Culicidae) and Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    AhbiRami, Rattanam; Zuharah, Wan Fatma; Thiagaletchumi, Maniam; Subramaniam, Sreeramanan; Sundarasekar, Jeevandran

    2014-01-01

    Natural insecticides from plant origin against mosquito vectors have been the main concern for research due to their high level of eco-safety. Control of mosquitoes in their larval stages are an ideal method since Aedes larvae are aquatic, thus it is easier to deal with them in this habitat. The present study was specifically conducted to explore the larvicidal efficacy of different plant parts of Ipomoea cairica (L.) or railway creeper crude extract obtained using two different solvents; methanol and acetone against late third-stage larvae of Aedes albopictus (Skuse) and Aedes aegypti (L.) (Diptera: Culicidae). Plant materials of I. cairica leaf, flower, and stem were segregated, airdried, powdered, and extracted using Soxhlet apparatus. Larvicidal bioassays were performed by using World Health Organization standard larval susceptibility test method for each species which were conducted separately for different concentration ranging from 10 to 450 ppm. Both acetone and methanol extracts showed 100% mortality at highest concentration tested (450 ppm) after 24 h of exposure. Results from factorial ANOVA indicated that there were significant differences in larvicidal effects between mosquito species, solvent used and plant parts (F=5.71, df=2, Paegypti with LC50 of 101.94 ppm followed by Ae. albopictus with LC50 of 105.59 ppm compared with other fractions of I. cairica extract obtained from flower, stem, and when methanol are used as solvent. The larvae of Ae. aegypti appeared to be more susceptible to I. cairica extract with lower LC50 value compared with Ae. albopictus (F=8.83, df=1, Pinsecticide for the control of Aedes mosquitoes. This study quantified the larvicidal property of I. cairica extract, providing information on lethal concentration that may have potential for a more eco-friendly Aedes mosquito control program.

  7. Reduced Incidence of Chikungunya Virus Infection in Communities with Ongoing Aedes Aegypti Mosquito Trap Intervention Studies - Salinas and Guayama, Puerto Rico, November 2015-February 2016.

    Science.gov (United States)

    Lorenzi, Olga D; Major, Chelsea; Acevedo, Veronica; Perez-Padilla, Janice; Rivera, Aidsa; Biggerstaff, Brad J; Munoz-Jordan, Jorge; Waterman, Stephen; Barrera, Roberto; Sharp, Tyler M

    2016-01-01

    Aedes species mosquitoes transmit chikungunya virus, as well as dengue and Zika viruses, and bite most often during the day.* Infectious mosquito bites frequently occur in and around homes (1,2). Caribbean countries first reported local transmission of chikungunya virus in December 2013, and soon after, chikungunya virus spread throughout the Americas (3). Puerto Rico reported its first laboratory-positive chikungunya case in May 2014 (4), and subsequently identified approximately 29,000 suspected cases throughout the island by the end of 2015.(†) Because conventional vector control approaches often fail to result in effective and sustainable prevention of infection with viruses transmitted by Aedes mosquitoes (5), and to improve surveillance of mosquito population densities, CDC developed an Autocidal Gravid Ovitrap (AGO) (6) to attract and capture the female Aedes aegypti mosquitoes responsible for transmission of infectious agents to humans (Figure). The AGO trap is a simple, low-cost device that requires no use of pesticides and no servicing for an extended period of time (6). PMID:27171600

  8. Characterization of N-linked oligosaccharides in chorion peroxidase of Aedes aegypti mosquito.

    Science.gov (United States)

    Li, Junsuo S; Li, Jianyong

    2005-09-01

    A peroxidase is present in the chorion of Aedes aegypti eggs and catalyzes chorion protein cross-linking during chorion hardening, which is critical for egg survival in the environment. The unique chorion peroxidase (CPO) is a glycoprotein. This study deals with the N-glycosylation site, structures, and profile of CPO-associated oligosaccharides using mass spectrometric techniques and enzymatic digestion. CPO was isolated from chorion by solubilization and several chromatographic methods. Mono-saccharide composition was analyzed by HPLC with fluorescent detection. Our data revealed that carbohydrate (D-mannose, N-acetyl D-glucosamine, D-arabinose, N-acetyl D-galactosamine, and L-fucose) accounted for 2.24% of the CPO molecular weight. A single N-glycosylation site (Asn328-Cys- Thr) was identified by tryptic peptide mapping and de novo sequencing of native and PNGase A-deglycosylated CPO using matrix-assisted laser/desorption/ionization time-of-flight mass spectrometry (MALDI/TOF/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). The Asn328 was proven to be a major fully glycosylated site. Potential tryptic glycopeptides and profile were first assessed by MALDI/TOF/MS and then by precursor ion scanning during LC/MS/MS. The structures of N-linked oligosaccharides were elucidated from the MS/MS spectra of glycopeptides and exoglycosidase sequencing of PNGase A-released oligosaccharides. These CPO-associated oligosaccharides had dominant Man3GlcNAc2 and Man3 (Fuc) GlcNAc2 and high mannose-type structures (Man(4-8)GlcNAc2). The truncated structures, Man2GlcNAc2 and Man2 (Fuc) GlcNAc2, were also identified. Comparison of CPO activity and Stokes radius between native and deglycosylated CPO suggests that the N-linked oligosaccharides influence the enzyme activity by stabilizing its folded state.

  9. Mosquito larvicidal efficacy of seaweed extracts against dengue vector of Aedes aegypti

    Institute of Scientific and Technical Information of China (English)

    Ravikumar S; M Syed Ali; J Margaret Beula

    2011-01-01

    Objective:To identify the larvicidal activity of the seaweed extracts. Methods:Seaweed extracts of Enteromorpha intestinalis (E. intestinalis), Dictyota dichotoma (D. dichotoma) and Acanthopora spicifera (A. spicifera) were dissolved in dimethylsulfoxide (DMSO) to prepare a graded series of concentration. Batches of 25 early 4th instars larvae of Aedes aegypti were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (0.01-0.1 mg). Each experiment was conducted in three replicates. A control group consisted of 1 mL of DMSO and 99 mL of distilled water only. After 24 h, the percentage of mortality was identified with the formula: %of mortality=[(%of test mortality-%of control mortality)/(100-%of control mortality)]×100. Results:The extract of D. dichotoma showed minimum level of LC50 value (0.068 3±0.008 4 μg/mL) and LC90 value was 0.140 1. The regression equations of D. dichotoma and E. intestinalis for 4th instar larvae were Y=0.333 + 0.684x (R2=0.946) and Y=0.600 + 0.781x (R2=0.812), respectively. The results of the preliminary phytochemical constituents showed the presence of saponin, steroids, terpenoid, phenols, protein and sugars. Conclusions:It can be concluded from the present study that, the ethanolic extracts of seaweed of D. dichotoma possess active compounds for development of larvicidal ativity.

  10. Synergistic action of octopamine receptor agonists on the activity of selected novel insecticides for control of dengue vector Aedes aegypti (Diptera: Culicidae) mosquito.

    Science.gov (United States)

    Ahmed, Mohamed Ahmed Ibrahim; Vogel, Christoph Franz Adam

    2015-05-01

    Studying insecticide resistance in mosquitoes has attracted the attention of many scientists to elucidate the pathways of resistance development and to design novel strategies in order to prevent or minimize the spread and evolution of resistance. Here, we tested the synergistic action of piperonyl butoxide (PBO) and two octopamine receptor (OR) agonists, amitraz (AMZ) and chlordimeform (CDM) on selected novel insecticides to increase their lethal action on the fourth instar larvae of Aedes aegypti L. However, chlorfenapyr was the most toxic insecticide (LC50 = 193, 102, and 48 ng/ml, after 24, 48, and 72 h exposure, respectively) tested. Further, PBO synergized all insecticides and the most toxic combinatorial insecticide was nitenpyram even after 48 and 72 h exposure. In addition, OR agonists significantly synergized most of the selected insecticides especially after 48 and 72 h exposure. The results imply that the synergistic effects of amitraz are a promising approach in increasing the potency of certain insecticides in controlling the dengue vector Ae. aegypti mosquito.

  11. In vitro Mosquito Larvicidal Activity of Marine Algae Against the Human Vectors, Culex quinquefasciatus (Say and Aedes aegypti (Linnaeus (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Akbar Idhayadhulla

    2011-01-01

    Full Text Available A total of twenty marine algae were collected from the rocky intertidal and subtidal regions of the southwest coast of India and extracted in methanol. The extracts were evaluated for larvicidal activity against the second and third instar larvae of the human vector mosquito Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae. Analysis on the activity profile of the above marine algae indicated that the early stage larvae were very sensitive to seven seaweed extracts that had been tested. Among the seven marine algae, Lobophora variegata was highly potential, showing LD50 value of 70.38 and 79.43 g mL-1 on the 2nd instar larvae of A. aegypti and C. quinquefasciatus respectively. The rank of larvicidal potency in highly active algae in the descending order is as follows: Lobophora variegata (Dictyotaceae>Spatoglossum asperum (Dictyotaceae>Stoechospermum marginatum (Dictyotaceae>Sargassum wightii (Sargassaceae >Acrosiphonia orientalis (Acrosiphoniaceae>Centroceras clavulatum (Ceramiacea>Padina tetrastromatica (Dictyotaceae. This is the first report that envisaged the mosquito larvicidal efficacy of L. variegata from the Indian coast. Therefore, this marine alga could be recognized as a potential resource of natural insecticide and can be developed to replace synthetic insecticides in future.

  12. 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.

  13. Larvicidal activity and GC-MS analysis of flavonoids of Vitex negundo and Andrographis paniculata against two vector mosquitoes Anopheles stephensi and Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Keerti Gautam

    2013-08-01

    Full Text Available Background & objectives: Development of insect resistance to synthetic pesticides, high operational cost and environmental pollution have created the need for developing alternative approaches to control vector-borne diseases. In the present study, larvicidal activity of flavonoid extracts of different parts of Vitex negundo (Linnaeus and Andrographis paniculata (Nees have been studied against the late III or early IV instar larvae of Aedes aegypti and Anopheles stephensi (Liston. Methods: Flavonoids were extracted from different parts of the selected plants using standard method. Bioassay test was carried out by WHO method for determination of larvicidal activity against mosquitoes. Different compounds of the most active extract were identified by the gas chromatography-mass spectrometry (GC-MS analysis. Results: Flavonoid extract of whole aerial part of A. paniculata was found to be inactive against the selected larvae of Ae. aegypti even at the concentration of 600 ppm, whereas it caused 70% mortality in An. stephensi at the concentration of 200 ppm. Flavonoid extract of flower-buds produced highest mortality (100% at the concentration of 600 ppm for the late III or early IV instar larvae of Ae. aegypti and at the concentration of 200 ppm for the larvae of An. stephensi. GC-MS analysis of the most active flavonoid extract from flower-buds of Vitex showed 81 peaks. Phenol (26.83% area, naphthalene (4.95% area, 2,3-dihydrobenzofuran (6.79% area, Phenol-2,4-Bis (1,1-dimethyl (4.49% area, flavones 4'-OH,5-OH,7-di-O-glucoside (0.25% area and 5-hydroxy- 3,6,7,3',4'-pentamethoxy flavones (0.80% area were present in major amount. Conclusion: Flavonoid extracts from different parts of two selected plants possess larvicidal activity against two selected mosquito species, hence, could be utilized for developing flavonoid-based, ecofriendly insecticide as an alternative to synthetic insecticides.

  14. The genetic architecture of a complex trait: Resistance to multiple toxins produced by Bacillus thuringiensis israelensis in the dengue and yellow fever vector, the mosquito Aedes aegypti.

    Science.gov (United States)

    Bonin, Aurélie; Paris, Margot; Frérot, Hélène; Bianco, Erica; Tetreau, Guillaume; Després, Laurence

    2015-10-01

    The bacterial insecticide Bacillus thuringiensis subsp. israelensis (Bti) is an increasingly popular alternative to chemical insecticides for controlling mosquito populations. Because Bti toxicity relies on the action of four main toxins, resistance to Bti is very likely a complex phenotype involving several genes simultaneously. Dissecting the underlying genetic basis thus requires associating a quantitative measure of resistance to genetic variation at many loci in a segregating population. Here, we undertake this task using the dengue and yellow fever vector, the mosquito Aedes aegypti, as a study model. We conducted QTL (Quantitative Trait Locus) and admixture mapping analyses on two controlled crosses and on an artificial admixed population, respectively, all obtained from resistant and susceptible lab strains. We detected 16 QTL regions, among which four QTLs were revealed by different analysis methods. These four robust QTLs explained altogether 29.2% and 62.2% of the total phenotypic variance in the two QTL crosses, respectively. They also all showed a dominant mode of action. In addition, we found six loci showing statistical association with Bti resistance in the admixed population. Five of the supercontigs highlighted in this study contained candidate genes as suggested by their function, or by prior evidence from expression and/or outlier analyses. These genomic regions are thus good starting points for fine mapping of resistance to Bti or functional analyses aiming at identifying the underlying genes and mutations. Moreover, for the purpose of this work, we built the first Ae. aegypti genetic map based on markers associated with genes expressed in larvae. This genetic map harbors 229 SNP markers mapped across the three chromosomes for a total length of 311.9cM. It brought to light several assembly discrepancies with the reference genome, suggesting a high level of genome plasticity in Ae. aegypti.

  15. Genetically Modified Mosquito: Myth and Reality

    Directory of Open Access Journals (Sweden)

    Teh Su Yean

    2013-02-01

    Full Text Available Sterile Insect Technique (SIT has been applied successfully in some agricultural pest control programs in the past, but in many cases, success has not been sustainable in the long run. Various attempts have been made to duplicate this limited success SIT application in agriculture to other areas of applications, particularly in vector control. For example, a recent mosquito control program has been initiated in Malaysia to eliminate dengue-mosquitoes Aedes aegypti by releasing large amount of genetically modified GM male mosquitoes into the field to outcompete the wild male mosquitoes. Field experimental data that has been made available in the literature is limited, rendering it difficult to make independent assessment on its short-term efficacy and long-term sustainability of this GM control strategy. This paper presents a preliminary assessment of the effectiveness of GM mosquito in controlling dengue mosquito population by means of model simulations via DEER (Dengue Encephalitis Eradication Routines. Preliminary results indicate negative conclusion regarding the effectiveness of GM mosquitoes in controlling wild A. aegypti population over the long-term. Essentially, significant reduction of wild mosquito population is possible only if large over-flooding ratios are applied. Further, repeated releases must be maintained over an infinite time horizon to continue to sustain low population of mosquitoes. Major difficulty remains to be resolved. In particular, in-depth costbenefit analysis on this control program is essential to ensure long-term institutional and social support.

  16. 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...

  17. Risk associated with the release of Wolbachia-infected Aedes aegypti mosquitoes into the environment in an effort to control Dengue.

    Directory of Open Access Journals (Sweden)

    Justine V Murray

    2016-03-01

    Full Text Available Background: In an effort to eliminate dengue, a successful technology was developed with the stable introduction of the obligate intracellular bacteria Wolbachia pipientis into the mosquito Aedes aegypti to reduce its ability to transmit dengue fever due to life shortening and inhibition of viral replication effects. An analysis of risk was required before considering release of the modified mosquito into the environment.Methods: Expert knowledge and a risk assessment framework was used to identify risk associated with the release of the modified mosquito. Individual and group expert elicitation was performed to identify potential hazards. A Bayesian network (BN was developed to capture the relationship between hazards and the likelihood of events occurring. Risk was calculated from the expert likelihood estimates populating the BN and the consequence estimates elicited from experts.Results: The risk model for ‘Don’t Achieve Release’ provided an estimated 46% likelihood that the release would not occur by a nominated time, but generated an overall risk rating of very low. The ability to obtain compliance had the greatest influence on the likelihood of release occurring. The risk model for ‘Cause More Harm’ provided a 12.5% likelihood that more harm would result from the release, but the overall risk was considered negligible. The efficacy of mosquito management had the most influence, with the perception that the threat of dengue fever had been eliminated, resulting in less household mosquito control, was scored as the highest ranked individual hazard (albeit low risk.Conclusions: The risk analysis was designed to incorporate the interacting complexity of hazards that may affect the release of the technology into the environment. The risk analysis was a small but important implementation phase in the success of this innovative research introducing a new technology to combat dengue transmission in the environment.

  18. Mosquito larvicidal effect of orthophosporic acid and lactic acid individually or their combined form on Aedes aegypti

    Institute of Scientific and Technical Information of China (English)

    Supratik Chakraborty; Someshwar Singha; Goutam Chandra

    2010-01-01

    Objective: To observe the effect of two common organic acids on the larvae of Aedes aegypti (Ae. aegypti) (L), the natural vector of dengue fever/dengue hemorrhage fever, chikugunya and allergic skin reaction especially in children. Methods: Two common organic acids (lactic acid and orthophosporic acid of gradually increasing concentration) were used against laboratory reared third instars larvae of Ae. aegypti in order to observe the rate of mortality after 8, 16 and 24 h of post exposure respectively in laboratory. Results: Larval mortality rates recorded were in the following sequences: orthophosphoric acid and lactic acid at 1:1 combination >orthophosphoric acid>lactic acid. Conclusions: These two organic acids may be used perfectly in combination (1:1) along with other conventional vector control methods to reduce the Ae. aegypti population, especially in those areas where surveillance and supervisory mechanism are poor or insufficient.

  19. Spatial analysis of wing geometry in dengue vector mosquito, Aedes aegypti (L. (Diptera: Culicidae, populations in Metropolitan Manila, Philippines

    Directory of Open Access Journals (Sweden)

    Thaddeus M Carvajal

    2016-01-01

    Interpretation & conclusion: The newly modified wing preparation procedure was able to capture a complete coverage of the wings of Ae. aegypti, thus providing a stronger separation power for very close populations in an urban area. It is also noteworthy that the results of IBD and SA supported the findings of GM in the population structuring of male and female Ae. aegypti. The outcome of the study increases our understanding of the vector, which would be useful in developing effective control strategies.

  20. 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

    Directory of Open Access Journals (Sweden)

    Jude Pavilupillai J

    2012-11-01

    Full Text Available Abstract Background 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. Methods 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 to18 ppt to determine the toxicity of Bacillus thuringiensis to fresh and brackish water-derived larvae of Ae. aegypti. Results 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 LC 50 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

  1. Effect of Novaluron (Rimon 10 EC) on the mosquitoes Anopheles albimanus, Anopheles pseudopunctipennis, Aedes aegypti, Aedes albopictus and Culex quinquefasciatus from Chiapas, Mexico.

    Science.gov (United States)

    Arredondo-Jiménez, J I; Valdez-Delgado, K M

    2006-12-01

    Dengue fever is a serious problem in Mexico and vector control has not been effective enough at preventing outbreaks. Malaria is largely under control, but it is important that new control measures continue to be developed. Novaluron, a novel host-specific insect growth regulator and chitin synthesis inhibitor, has proved to be effective against agricultural pests, but its efficacy against larval mosquito vectors under field conditions remains unknown. In accordance with the World Health Organization Pesticide Evaluation Scheme, phase I, II and III studies were conducted to evaluate the efficacy and residual effect of Novaluron (Rimon 10 EC, Makhteshim, Beer-Sheva, Israel) on the malaria vectors Anopheles albimanus Wiedemann (Diptera: Culicidae) and Anopheles pseudopunctipennis Theobald, the dengue vectors Aedes aegypti (L) and Aedes albopictus Skuse and the nuisance mosquito Culex quinquefasciatus Say. Laboratory susceptibility tests yielded diagnostic concentrations for all five target species. Field trials to identify the optimum field dosage of Novaluron against Anopheles mosquitoes were carried out under semi-natural conditions in artificial plots and in vessels with wild mosquitoes. Efficacy was measured by monitoring mortality of larvae and pupae and the percentage of inhibition of emergence from floating cages. Dosages of Novaluron for field tests were based on pupal LC(99) (lethal concentration 99%) of An. pseudopunctipennis (0.166 mg/L) in plots and average pupal LC(99) of Ae. aegypti and Ae. albopictus (0.55 mg/L). At all dosages tested, Novaluron significantly reduced larval populations of An. albimanus, Culex coronator Dyar & Knab, Ae. albopictus and Cx. quinquefasciatus by approximately 90%, inhibited adult emergence of An. albimanus and An. pseudopunctipennis by approximately 97% for almost 4 months in experimental plots, and inhibited adult emergence of Ae. aegypti and Ae. albopictus by approximately 97% for up to 14 weeks. Recommended dosages of

  2. Creams formulated with Ocimum gratissimum L. and Lantana camara L. crude extracts and fractions as mosquito repellents against Aedes aegypti L. (Diptera: Culicidae).

    Science.gov (United States)

    Keziah, Ezeike Amarachi; Nukenine, Elias Nchiwan; Danga, Simon Pierre Yinyang; Younoussa, Lame; Esimone, Charles Okechukwu

    2015-01-01

    Mosquitoes are the most deadly vectors of parasites that cause diseases such as malaria, yellow fever, and filariasis. In view of the recent increased interest in developing plant origin insecticides as an alternative to chemical insecticides, the objective of this study was to determine the repellent activity of creams formulated with methanol crude extract (MCE), hexane fraction (HF), and ethyl acetate fractions (EAFs) of Ocimum gratissimum and Lantana camara leaves in single and combined actions against female Aedes aegypti. Evaluation was carried out in the net cages (30 by 30 by 30 cm) containing 60 blood-starved female mosquitoes each and were assayed in the laboratory condition following World Health Organization 2009 protocol. All formulations (single and mixture) were applied at 2, 4, 6, and 8 mg/cm(2) in the exposed area of human hands. Only acetone + white soft paraffin served as negative control and odomos (12% DEET) as positive control. All the formulations presented good protection against mosquito bites without any allergic reaction by the human volunteers. The repellent activity was dependent on the strength of the extracts and fractions. Among the tested formulations, the maximum protection time was observed in MCE (120 min) and EAF (150 min) of O. gratissimum; MCE:MCE (150 min) and HF:HF (120 min) mixtures of both plants. In addition, MCE:MCE and HF:HF mixtures from both plants showed possible synergistic effect. From the results, the combination of O. gratissimum and L. camara to formulate natural mosquito repellent using small amount of extracts can be encouraging to be an alternative to conventional DEET. PMID:25881633

  3. Evaluation of fifteen local plants as larvicidal agents against an Indian strain of dengue fever mosquito, Aedes aegypti L. (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Sarita eKumar

    2012-04-01

    Full Text Available 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 development of alternative strategies using eco-friendly, environmentally safe, bio-degradable plant products which are non-toxic to non target organisms too. In view of this, fifteen plants 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 45ºC 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 ten 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 extracts of Lantana camara to be most effective extracts exhibiting a significant LC50 value of 30.71 ppm while the Phyllanthus emblica fruit extracts were found to be least effective with an LC50 value of 298.93 ppm. The extracts made from different parts of other five plants; Achyranthes aspera, Zingiber officinalis, Ricinus communis, Trachyspermun 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 Aedes aegypti larvae. Further investigations would be needed to isolate and identify the primary component responsible for the larvicidal efficiency of the

  4. 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.

  5. 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. PMID:26135160

  6. Manejo de la resistencia a insecticidas en el mosquito Aades aegypti (Linneus, 1762) en Guerrero, México.

    OpenAIRE

    Chino Cantor, Araceli

    2014-01-01

    El dengue es una de las enfermedades más graves a nivel mundial en salud pública, y a la fecha el uso de insecticidas químicos ha sido la principal medida de control del vector Aedes aegypti transmisor del virus causal del dengue. Con la finalidad de aportar bases para definir una estrategia de manejo regional de insecticidas, se determinó la susceptibilidad de poblaciones de Aedes aegypti L., provenientes de tres regiones de Guerrero, México (Tierra Caliente, Costa Chica y Acapulco), a los i...

  7. 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.

  8. 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.

  9. Synergistic effect of Andrographis echioides and Cadaba trifoliata leaf extracts against larvae of dengue mosquito Aedes aegypti L

    Institute of Scientific and Technical Information of China (English)

    Sankaran Rajkumar; Arulsamy Jebanesan; Rajarathinavelu Nagarajan

    2012-01-01

    Objective: The larvicidal potential of Andrographis echioides and Cadaba trifoliata leaf extract was tested separately against larvae of Aedes aegypti and also tested mixture of these two plant extracts for synergistic effect against the larvae. Methods: Pulverized leaves of A. echioides and C.trifoliata were subjected separately to soxhlet extraction using organic solvent of ethanol. These two plant extracts were examined separately against 4th instar larvae of A.aegypti with gradually increasing concentration i.e. from 50 to 250mg/l using WHO protocol. To observe the synergistic effect, extracts of these two plants were mixed at different concentrations and tested against the larva. The 24h LC50 values of individual plant extract and mixed extracts were determined following probit analysis. Results: A. echioides extract shows more lethal effect than C. trifoliata extract towards larvae of A.aegypti with LC50 values of 108.3 and 123.4 mg/l, respectively, whereas , synergistic larvicidal effect was found to be even more effective than the plant extract tested separately in terms of LC50 being 68.3 mg/l. Conclusions: From the results, it is evident that synergistic effect of A. echioides and C. trifoliata can be considered as a more powerful arsenal for the control of A.aegypti than the usage of these two extract separately.

  10. Cloning and sequencing of the blood meal-induced late trypsin gene from the mosquito Aedes aegypti and characterization of the upstream regulatory region.

    Science.gov (United States)

    Barillas-Mury, C; Wells, M A

    1993-01-01

    A 4.1 kb genomic clone of the late trypsin gene from the mosquito Aedes aegypti was isolated, mapped and subcloned. A 1.6 kb subclone, corresponding to 1.1 kb of upstream regulatory region and 0.5 kb of coding region, was sequenced. The gene has no introns within the coding region. The 5' end of the mature mRNA was mapped using primer extension analysis. A TATA box consensus sequence (TATAAA) was found at position -31 from the 5' end of the mature mRNA. A cluster of five repeat sequences homologous to the yeast GCN4 DNA binding site was found within 200 nucleotides upstream of the cap site. GCN4 is required for derepression mediated control of general amino acid biosynthesis in response to amino acid starvation in yeast. It activates the transcription of at least twenty different genes coding for enzymes involved in amino acid biosynthesis. The presence of this cluster of consensus sequences suggests that a protein similar to GCN4 might regulate expression of the late trypsin gene in the mosquito. Southern blot analysis of genomic DNA indicates that late trypsin is a single copy gene. PMID:9087537

  11. Structure, expression, and hormonal control of genes from the mosquito, Aedes aegypti, which encode proteins similar to the vitelline membrane proteins of Drosophila melanogaster.

    Science.gov (United States)

    Lin, Y; Hamblin, M T; Edwards, M J; Barillas-Mury, C; Kanost, M R; Knipple, D C; Wolfner, M F; Hagedorn, H H

    1993-02-01

    Genomic and cDNA clones of a gene expressed after a blood meal in the mosquito, Aedes aegypti, were identified as having significant similarity to the vitelline membrane protein genes of Drosophila melanogaster. The predicted protein had unusually high contents of alanine, histidine, and proline and contained a region of hydrophobic amino acids that was highly conserved in the predicted protein of the D. melanogaster vitelline membrane protein genes. The 15a gene was expressed from 5 to 40 hr after a blood meal. It was expressed only in the follicle cells of the ovary, particularly in the cells surrounding the oocyte. The 15a gene was expressed in ovaries of the blood-fed, decapitated female in response to an injection of 20-hydroxyecdysone, and in ovaries from non-blood-fed females incubated with the hormone, even in the presence of cycloheximide. A second gene, with weaker homology to 15a, is presumably another member of a family of related genes, as is the case with D. melanogaster vitelline membrane protein genes. This second gene contained a coding sequence similar to a decapeptide recently isolated from mosquito ovaries as an "oostatic factor" (Borovsky et al., FASEB J. 4, 3015-3020, 1990). PMID:8432405

  12. 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), 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. PMID:26337270

  13. 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.

  14. 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 ...

  15. Optimal strategies for Aedes aegypti mosquito control via transgenic and sterile insect techniques: endemics and emerging outbreaks

    OpenAIRE

    Seirin Lee, S.; Baker, R. E.; Gaffney, E.A.; White, S. M.

    2013-01-01

    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...

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

    Science.gov (United States)

    Estes, Sue M.

    2011-01-01

    Dengue (Breakbone) fever is caused by one of four viruses carried by mosquitoes in tropical and subtropical areas. Cases have increased dramatically in the past few decades; there are currently approximately 100 million infections annually around the globe. Our project will integrate environmental observations, including weather, land use, vegetation type, amount and greenness, soil moisture, and mosquito populations with investigations of the human dynamics of the system via household surveys.

  17. Phylogeography of Aedes aegypti (yellow fever mosquito) in South Florida: mtDNA evidence for human-aided dispersal.

    Science.gov (United States)

    Damal, Kavitha; Murrell, Ebony G; Juliano, Steven A; Conn, Jan E; Loew, Sabine S

    2013-09-01

    The invasive dengue vector Aedes aegypti has persisted for > 200 years in South Florida in the United States. We tested the hypotheses that Florida's landscape creates dispersal barriers and corridors and that long-distance human-aided dispersal structures populations of Ae. aegypti. We evaluated the phylogeography of 362 individuals from Florida's East and West Coasts with a 760-bp (418- and 342-bp fragments of ND5 and ND4, respectively) mitochondrial sequence. Populations from these two coasts were not significantly differentiated, suggesting that limited urbanization in central Florida is not a strong barrier to gene flow. Evidence for long-distance dispersal between Ft. Lauderdale and the West and Ft. Myers and the East indicates the importance of human-aided dispersal. West Coast populations showed no genetic differentiation, indicating that West Coast rivers and bays did not significantly impede gene flow. Phylogeographic analysis of haplotypes showed two distinct matrilines with no geographic patterns, suggesting multiple introductions or balancing selection.

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

    Directory of Open Access Journals (Sweden)

    Beatriz Louise J Almanzor

    2016-01-01

    Interpretation & conclusion: 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.

  19. 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. PMID:24724289

  20. 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.

  1. A Novel in vitro Bioassay to Explore the Repellent Effects of Compounds Against Mosquito Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Rehman, Junaid U; Tabanca, Nurhayat; Khan, Ikhlas A

    2016-01-01

    Mosquitoes are vectors for many pathogens resulting in many deaths of humans. Repellents play an important role in reducing mosquito bites and the spread of mosquito-borne diseases. Currently, Klun & Debboun (K & D) and human-arm-based bioassay systems are used to identify repellent properties of compounds, extracts, and essential oils. Risks involved with human-arm-based systems are allergic reactions and limited replicates. We are reporting an in vitro bioassay method “NCNPR repellent bioassay (NCNPR-RB)” that can closely simulate the results of the cloth patch bioassay system used to determine repellency against mosquitoes. The NCNPRRB method uses heat to attract mosquito and edible collagen sheets as an alternate to human skin. Multiple plant compounds with documented repellency were tested. DEET (N,N-diethyl-3-methylbenzamide) was used as a positive control. Treatments were prepared in EtOH and applied in dosages ranging from 0.011–1.5mg/cm2 to a 20-cm2 collagen sheet. The number of mosquitoes commencing to bite per probe was recorded visually for 1 min. The minimum effective dosage (mg/cm2) of compounds: DEET (0.021), carvacrol (0.011), thymol (0.013), undecanoic acid (0.023), thymol methyl ether (0.269), and 2-nonanone (>0.375 mg/cm2) determined in NCNPRRB were similar to those reported in literature using a cloth patch bioassay system. The NCNPR-RB can be used to screen compounds with reasonable reproducibility of the data at a faster rate than the cloth patch bioassay, which involves the use of human subjects. PMID:26590191

  2. 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

    concentrations of dopamine than females, and that dopamine concentrations decrease with age in both sexes. Dopamine levels increase in females following a blood meal suggesting that dopamine might be involved in ovarian- and/or egg-development. We also found that female mosquitoes have a higher tolerance...... to a short term thermal stress in a water bath than males up to 44 degrees C, however, both sexes die if exposed to short term temperatures between 44 and 45 degrees C. Finally, we did not find any indication that dopamine levels were associated with short time thermal stress response in female mosquitoes....

  3. DsRNA-mediated targeting of ribosomal transcripts RPS6 and RPL26 induces long-lasting and significant reductions in fecundity of the vector Aedes aegypti.

    Science.gov (United States)

    Estep, A S; Sanscrainte, N D; Becnel, J J

    2016-07-01

    Ribosomal transcripts produce critical proteins that are involved in most cellular production processes. Targeting ribosomal transcripts has produced mortality in mites and ticks but the effect of ribosomal transcript knockdown has not been thoroughly examined in mosquitoes. We examine the effects of triggers targeting four ribosomal proteins (RP) transcripts. Although no significant mortality was observed after dsRNA microinjection and subsequent blood feeding, significant contrasts were observed on fecundity. Triggers targeting RPS6 and RPL26 effectively reduced gene expression but more importantly, reduced reproductive output by more than 96% and 91% at the first oviposition while triggers targeting RPL1 and RPS2 did not cause a reduction although gene expression was reduced. Significantly reduced fecundity continued through a second oviposition cycle in dsRPS6 and dsRPL26 cohorts, although the effect was not as strong. Relative gene expression levels confirmed specific transcript knockdown up to 20days post-injection in mosquitoes that did not oviposit or produced reduced clutch sizes. Dissections at 36h post-blood meal indicated defects in oocyte provisioning. The strong phenotype produced by dsRPS6 allowed us to examine the effects in various tissues as well as the dose response, trigger format, delivery method and trigger specificity in Aedes aegypti. Strong knockdown was observed in the abdomen and the ovaries. Greater than 50ng of dsRPS6 significantly reduced fecundity but not when delivered in a sugar meal or as an siRNA. Similar bioassays with mutated dsRPS6 triggers indicates that up to three mismatches per possible siRNA are still effective in reducing fecundity. These studies indicate that while active and effective triggers can be developed for vector species, the lack of an efficient delivery method is the biggest barrier to use as a potential control method. PMID:27180677

  4. Temephos resistance and esterase activity in the mosquito Aedes aegypti in Havana, Cuba increased dramatically between 2006 and 2008.

    Science.gov (United States)

    Bisset, J A; Rodríguez, M M; Ricardo, Y; Ranson, H; Pérez, O; Moya, M; Vázquez, A

    2011-09-01

    Aedes aegypti (L.) (Diptera: Culicidae) control programmes in Cuba rely on the application of the organophosphate temephos for larval control. Hence, the monitoring of resistance to this insecticide is an essential component of such programmes. Here, 15 field populations from different municipalities of Havana City were assayed for resistance to temephos. High levels of resistance were detected in all strains and resistance ratios were highly correlated with esterase activity (P = 0.00001). Populations from three municipalities were tested in both 2006 and 2008; resistance and esterase activities both significantly increased during this 2-year period. Synergist studies demonstrated that neither glutathione transferases nor monooxygenases were associated with the increase in resistance to temephos in this period. The duration of the efficacy of commercial formulations of temephos in controlling Ae. aegypti populations in Havana City was reduced by the high level of temephos resistance observed; hence these data are of clear operational significance for the dengue control programme in Cuba. New integrated strategies to avoid further increases in temephos resistance in Cuba are necessary.

  5. 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.

  6. 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

  7. Integrating the public in mosquito management: active education by community peers can lead to significant reduction in peridomestic container mosquito habitats.

    Directory of Open Access Journals (Sweden)

    Kristen Healy

    Full Text Available 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

  8. 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.

  9. Workbook on Identification of Aedes Aegypti Larvae.

    Science.gov (United States)

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable yellow fever control workers to identify the larvae of "Aedes aegypti." The morphological features of mosquito larvae are illustrated in this partially programed text, and the distinguishing features of "A. aegypti" indicated. A glossary is included. (AL)

  10. Studies on effects ofAndrographis paniculata (Burm.f.) andAndrographis lineata nees (Family:Acanthaceae) extracts against two mosquitoesCulex quinquefasciatus (Say.) andAedes aegypti (Linn.)

    Institute of Scientific and Technical Information of China (English)

    Renugadevi G; Ramanathan T; Shanmuga priya R; Thirunavukkarasu P

    2013-01-01

    Objective:To investigate the studies on effects ofAndrographis paniculata(A. paniculata) (Burm.f.) andAndrographis lineata(A. lineata) nees(Family:Acanthaceae) extracts against two mosquitoesCulex quinquefasciatus(Cx. quinquefasciatus)(Say.) andAedes aegypti(Ae. aegypti) (Linn.).Methods:The aqueous and petroleum ether extracts of two plant species,A. paniculata andA. lineate were examined against the larvae ofA. aegypti(L.) andCx. quinquefasciatus with gradually increasing concentrationie. from50 to200 ppm of solvent extracts and to test their activity in combination with each other.Results:In a24 h bioassay experiment with plant extracts, highest mortalities were recorded at200 ppm of concentrations for leaves ofA. lineta andA. paniculata individually.For combination effect, only150 ppm of the mixture of solvent extracts of petroleum ether: aqueous(1:1) extracts showed100% mortality after24 h of exposure. Conclusions:The results show that, insecticides of plant combination is ecofriend and has better larvicidal activity compared to individual extracts.

  11. 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.

  12. 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...

  13. Rhamnolipids: solution against Aedes aegypti?

    OpenAIRE

    Silva, Vinicius L.; Lovaglio, Roberta B.; Claudio J. Von Zuben; Contiero, Jonas

    2015-01-01

    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 poten...

  14. An animal homolog of plant Mep/Amt transporters promotes ammonia excretion by the anal papillae of the disease vector mosquito Aedes aegypti.

    Science.gov (United States)

    Chasiotis, Helen; Ionescu, Adrian; Misyura, Lidiya; Bui, Phuong; Fazio, Kimberly; Wang, Jason; Patrick, Marjorie; Weihrauch, Dirk; Donini, Andrew

    2016-05-01

    The transcripts of three putative ammonia (NH3/NH4 (+)) transporters, Rhesus-like glycoproteins AeRh50-1, AeRh50-2 and Amt/Mep-like AeAmt1 were detected in the anal papillae of larval Aedes aegypti Quantitative PCR studies revealed 12-fold higher transcript levels of AeAmt1 in anal papillae relative to AeRh50-1, and levels of AeRh50-2 were even lower. Immunoblotting revealed AeAmt1 in anal papillae as a pre-protein with putative monomeric and trimeric forms. AeAmt1 was immunolocalized to the basal side of the anal papillae epithelium where it co-localized with Na(+)/K(+)-ATPase. Ammonium concentration gradients were measured adjacent to anal papillae using the scanning ion-selective electrode technique (SIET) and used to calculate ammonia efflux by the anal papillae. dsRNA-mediated reductions in AeAmt1 decreased ammonia efflux at larval anal papillae and significantly increased ammonia levels in hemolymph, indicating a principal role for AeAmt1 in ammonia excretion. Pharmacological characterization of ammonia transport mechanisms in the anal papillae suggests that, in addition to AeAmt1, the ionomotive pumps V-type H(+)-ATPase and Na(+)/K(+)-ATPase as well as NHE3 are involved in ammonia excretion at the anal papillae.

  15. Susceptibility profile of Aedes aegypti from Santiago Island, Cabo Verde, to insecticides.

    Science.gov (United States)

    Rocha, Hélio Daniel Ribeiro; Paiva, Marcelo Henrique Santos; Silva, Norma Machado; de Araújo, Ana Paula; Camacho, Denise dos Reis da Rosa de Azevedo; Moura, Aires Januário Fernandes da; Gómez, Lara Ferrero; Ayres, Constância Flávia Junqueira; Santos, Maria Alice Varjal de Melo

    2015-12-01

    In 2009, Cabo Verde diagnosed the first dengue cases, with 21,137 cases reported and Aedes aegypti was identified as the vector. Since the outbreak, chemical insecticides and source reduction were used to control the mosquito population. This study aimed to assess the susceptibility of A. aegypti populations from Santiago, Cabo Verde to insecticides and identify the mechanisms of resistance. Samples of A. aegypti eggs were obtained at two different time periods (2012 and 2014), using ovitraps in different locations in Santiago Island to establish the parental population. F1 larvae were exposed to different concentrations of insecticides (Bacillus thuringiensis var israelensis (Bti), diflubenzuron and temephos) to estimate the lethal concentrations (LC90) and calculate the respective rate of resistance (RR90). Semi-field tests using temephos-ABATE(®) were performed to evaluate the persistence of the product. Bottle tests using female mosquitoes were carried out to determine the susceptibility to the adulticides malathion, cypermethrin and deltamethrin. Biochemical and molecular tests were performed to investigate the presence of metabolic resistance mechanisms, associated with the enzymes glutathione S-transferases (GSTs), esterases and mixed-function oxidases (MFO) and to detect mutations or alterations in the sodium channel and acetylcholinesterase genes. A. aegypti mosquitoes from Santiago exhibited resistance to deltamethrin, cypermethrin (mortalityinsecticides used for vector control, deltamethrin and temephos. To our knowledge, this is the first report of temephos resistance in an African A. aegypti population. The low level of temephos resistance was maintained from 2012-2014, which suggested the imposition of selective pressure, although it was not possible to identify the resistance mechanisms involved. These data show that the potential failures in the local mosquito control program are not associated with insecticide resistance.

  16. Lethal ovitrap deployment for Aedes aegypti control: potential implications for non-target organisms.

    Science.gov (United States)

    Long, Sharron A; Jacups, Susan P; Ritchie, Scott A

    2015-06-01

    In Australia, dengue control combines source reduction with lethal ovitraps to reduce Aedes aegypti populations during outbreaks. Lethal ovitraps are considered a sustainable and environmentally friendly method of controlling container-inhabiting mosquitoes, however, to-date, this claim has not been quantified. This study assesses the potential impact of lethal ovitraps on non-target organisms when used to control Ae. aegypti in tropical Australia. For retention of specimens, we substituted standard sticky ovitraps for lethal ovitraps. We collected 988 Ae. aegypti and 44,132 non-target specimens over 13 months from 16 sites. Although Ae. aegypti comprised only 2.2% of the total collection, they were were the eighth most dominant taxa collected, on the 93(rd) percentile. Of the non-target organisms, Collembola were the dominant taxa, 44.2%, with 36.8% and 10.5% Diptera and Hymenoptera, respectively. Of the Dipterans, 61% were family Phoridae. Lethal ovitraps were visited by 90 insect or invertebrate families in total. Ovitraps are attractive to Collembola, Phoridae, Sciaridae, Formicidae, and Culicidae, with minimal attraction by Apidae and other commonly monitored non-target organisms. For container-inhabiting mosquitoes, LOs are cost effective operationally, requiring minimal staff resources for placement and retrieval.

  17. 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)

    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

  18. 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.

  19. Promising new tools to fight Aedes mosquitoes.

    Science.gov (United States)

    2016-08-01

    Two new tools for suppressing Aedes aegypti mosquito populations have been recommended for pilot testing. Carefully designed trials will be needed to see whether they actually reduce disease as well. Andréia Azevedo Soares reports. PMID:27516632

  20. 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

    2016-02-01

    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.

  1. 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

    Directory of Open Access Journals (Sweden)

    Orlando Salvador-Neto

    2016-01-01

    Full Text Available 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.

  2. 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

  3. The role of octopamine receptor agonists in the synergistic toxicity of certain insect growth regulators (IGRs) in controlling Dengue vector Aedes aegypti (Diptera: Culicidae) mosquito.

    Science.gov (United States)

    Ahmed, Mohamed Ahmed Ibrahim; Vogel, Christoph Franz Adam

    2016-03-01

    The synergistic action of octopamine receptor agonists (OR agonists) on many insecticide classes (e.g., organophosphorus, pyrethroids, and neonicotinoids) on Aedes aegypti L. has been reported recently. An investigation of OR agonist's effect on insect growth regulators (IGRs) was undertaken to provide a better understanding of the mechanism of action. Based on the IGR bioassay, pyriproxyfen was the most potent IGR insecticide tested (EC50=0.0019ng/ml). However, the lethal toxicity results indicate that diafenthiuron was the most potent insecticide (LC50=56ng/cm(2)) on A. aegypti adults after 24h of exposure. The same trend was true after 48 and 72h of exposure. Further, the synergistic effects of OR agonists plus amitraz (AMZ) or chlordimeform (CDM) was significant on adults. Among the tested synergists, AMZ increased the potency of the selected IGRs on adults the greatest. As results, OR agonists were largely synergistic with the selected IGRs. OR agonists enhanced the lethal toxicity of IGRs, which is a valuable new tool in the field of A. aegypti control. However, further field experiments need to be done to understand the unique potential role of OR agonists and their synergistic action on IGRs.

  4. 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.

  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

    2016-02-01

    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. Análisis de la unión de la toxina Cry11Bb1 de bacillus thuringiensis subesp. Medellín a vesículas del epitelio en borde de cepillo del mosquito Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Sergio Ordúz

    2000-02-01

    Full Text Available Las proteínas Cry11 son producidas por Bacillus thuringiensis, estas son potentes toxinas insecticidas contra larvas de mosquitos y su modo de acción se cree que es similar al de las toxinas del tipo Cry1, las cuales interactúan con el intestino medio de larvas de lepidópteros. En este trabajo, se estudió la interacción de la toxina de 94 kDa Cry11Bb de Bacillus thuringiensis subesp. medellin con el epitelio intestinal de larvas del mosquito Aedes aegypti utilizando vesículas de la membrana en borde de cepillo (VMBC. Un intermediario de la protoxina Cry11Bb de 68 kDa, y su forma activa 30/35 kDa se marcaron con Iodo-radioactivo e incubaron con las VMBC del mosquito. La protoxina marcada (125I-68 kDa interactuó específicamente con las vesículas y los experimentos de saturación en presencia de cantidades crecientes de vesículas mostraron que la interacción vesícula-125I-68 kDa fue saturable en el rango entre 10 a 80 ?g de VMBC. En contraste, la toxina marcada (125I-30/35 kDa no mostró ni unión específica, ni saturabilidad en la interacción. Adicionalmente, la toxina fue susceptible al ataque de las proteasas presentes en las vesículas y mediante la técnica de dynamic Light scattering, se evidenció que la toxina se presenta como un agregado proteico. Los resultados sugieren que la protoxina Cry11Bb de 68 kDa podría determinar la especificidad de la interacción y después de la unión ésta ser procesada hacia una forma funcional de 30/35 kDa capaz de interactuar con los lípidos de la membrana y generar, mediante la formación de poros, el desbalance osmótico que lleva a la muerte a las larvas de mosquitos.

  7. 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

    concentrations of dopamine than females, and that dopamine concentrations decrease with age in both sexes. Dopamine levels increase in females following a blood meal suggesting that dopamine might be involved in ovarian- and/or egg-development. We also found that female mosquitoes have a higher tolerance...... to a short term thermal stress in a water bath than males up to 44 °C, however, both sexes die if exposed to short term temperatures between 44 and 45 °C. Finally, we did not find any indication that dopamine levels were associated with short time thermal stress response in female mosquitoes. Keywords: HPLC...

  8. Genetic Drift during Systemic Arbovirus Infection of Mosquito Vectors Leads to Decreased Relative Fitness during Host Switching.

    Science.gov (United States)

    Grubaugh, Nathan D; Weger-Lucarelli, James; Murrieta, Reyes A; Fauver, Joseph R; Garcia-Luna, Selene M; Prasad, Abhishek N; Black, William C; Ebel, Gregory D

    2016-04-13

    The emergence of mosquito-borne RNA viruses, such as West Nile virus (WNV), is facilitated by genetically complex virus populations within hosts. Here, we determine whether WNV enzootic (Culex tarsalis, Cx. quinquefasciatus, and Cx. pipiens) and bridge vectors (Aedes aegypti) have differential impacts on viral mutational diversity and fitness. During systemic mosquito infection, WNV faced stochastic reductions in genetic diversity that rapidly was recovered during intra-tissue population expansions. Interestingly, this intrahost selection and diversification was mosquito species dependent with Cx. tarsalis and Cx. quinquefasciatus exhibiting greater WNV divergence. However, recovered viral populations contained a preponderance of potentially deleterious mutations (i.e., high mutational load) and had lower relative fitness in avian cells compared to input virus. These findings demonstrate that the adaptive potential associated with mosquito transmission varies depending on the mosquito species and carries a significant fitness cost in vertebrates.

  9. Genetic Drift during Systemic Arbovirus Infection of Mosquito Vectors Leads to Decreased Relative Fitness during Host Switching.

    Science.gov (United States)

    Grubaugh, Nathan D; Weger-Lucarelli, James; Murrieta, Reyes A; Fauver, Joseph R; Garcia-Luna, Selene M; Prasad, Abhishek N; Black, William C; Ebel, Gregory D

    2016-04-13

    The emergence of mosquito-borne RNA viruses, such as West Nile virus (WNV), is facilitated by genetically complex virus populations within hosts. Here, we determine whether WNV enzootic (Culex tarsalis, Cx. quinquefasciatus, and Cx. pipiens) and bridge vectors (Aedes aegypti) have differential impacts on viral mutational diversity and fitness. During systemic mosquito infection, WNV faced stochastic reductions in genetic diversity that rapidly was recovered during intra-tissue population expansions. Interestingly, this intrahost selection and diversification was mosquito species dependent with Cx. tarsalis and Cx. quinquefasciatus exhibiting greater WNV divergence. However, recovered viral populations contained a preponderance of potentially deleterious mutations (i.e., high mutational load) and had lower relative fitness in avian cells compared to input virus. These findings demonstrate that the adaptive potential associated with mosquito transmission varies depending on the mosquito species and carries a significant fitness cost in vertebrates. PMID:27049584

  10. Ecological modeling of Aedes aegypti (L. pupal production in rural Kamphaeng Phet, Thailand.

    Directory of Open Access Journals (Sweden)

    Jared Aldstadt

    Full Text Available BACKGROUND: Aedes aegypti (L. is the primary vector of dengue, the most important arboviral infection globally. Until an effective vaccine is licensed and rigorously administered, Ae. aegypti control remains the principal tool in preventing and curtailing dengue transmission. Accurate predictions of vector populations are required to assess control methods and develop effective population reduction strategies. Ae. aegypti develops primarily in artificial water holding containers. Release recapture studies indicate that most adult Ae. aegypti do not disperse over long distances. We expect, therefore, that containers in an area of high development site density are more likely to be oviposition sites and to be more frequently used as oviposition sites than containers that are relatively isolated from other development sites. After accounting for individual container characteristics, containers more frequently used as oviposition sites are likely to produce adult mosquitoes consistently and at a higher rate. To this point, most studies of Ae. aegypti populations ignore the spatial density of larval development sites. METHODOLOGY: Pupal surveys were carried out from 2004 to 2007 in rural Kamphaeng Phet, Thailand. In total, 84,840 samples of water holding containers were used to estimate model parameters. Regression modeling was used to assess the effect of larval development site density, access to piped water, and seasonal variation on container productivity. A varying-coefficients model was employed to account for the large differences in productivity between container types. A two-part modeling structure, called a hurdle model, accounts for the large number of zeroes and overdispersion present in pupal population counts. FINDINGS: The number of suitable larval development sites and their density in the environment were the primary determinants of the distribution and abundance of Ae. aegypti pupae. The productivity of most container types

  11. Identifying the effective concentration for spatial repellency of the dengue vector Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Achee Nicole

    2012-12-01

    Full Text Available Abstract Background Current efforts are underway to quantify the chemical concentration in a treated air space that elicits a spatial repellent (deterrent response in a vector population. Such information will facilitate identifying the optimum active ingredient (AI dosage and intervention coverage important for the development of spatial repellent tools – one of several novel strategies being evaluated for vector-borne disease control. This study reports initial findings from air sampling experiments conducted under field conditions to describe the relationship between air concentrations of repellent AIs and deterrent behavior in the dengue vector, Aedes aegypti. Methods Air samples were taken inside and outdoors of experimental huts located in Pu Tuey Village, Kanchanaburi Province, Thailand in conjunction with mosquito behavioral evaluations. A mark-release-recapture study design using interception traps was used to measure deterrency of Ae. aegypti against 0.00625% metofluthrin coils and DDT-treated fabric (2g/m2 within separate experimental trials. Sentinel mosquito cohorts were positioned adjacent to air sampling locations to monitor knock down responses to AI within the treated air space. Air samples were analyzed using two techniques: the U.S. Environmental Protection Agency (USEPA Compendium Method TO-10A and thermal desorption (TD. Results Both the USEPA TO-10A and TD air sampling methods were able to detect and quantify volatized AIs under field conditions. Air samples indicated concentrations of both repellent chemicals below thresholds required for toxic responses (mortality in mosquitoes. These concentrations elicited up to a 58% and 70% reduction in Ae. aegypti entry (i.e., deterrency into treated experimental huts using metofluthrin coils and DDT-treated fabric, respectively. Minimal knock down was observed in sentinel mosquito cohorts positioned adjacent to air sampling locations during both chemical evaluations. Conclusions

  12. Susceptibility profile of Aedes aegypti from Santiago Island, Cabo Verde, to insecticides.

    Science.gov (United States)

    Rocha, Hélio Daniel Ribeiro; Paiva, Marcelo Henrique Santos; Silva, Norma Machado; de Araújo, Ana Paula; Camacho, Denise dos Reis da Rosa de Azevedo; Moura, Aires Januário Fernandes da; Gómez, Lara Ferrero; Ayres, Constância Flávia Junqueira; Santos, Maria Alice Varjal de Melo

    2015-12-01

    In 2009, Cabo Verde diagnosed the first dengue cases, with 21,137 cases reported and Aedes aegypti was identified as the vector. Since the outbreak, chemical insecticides and source reduction were used to control the mosquito population. This study aimed to assess the susceptibility of A. aegypti populations from Santiago, Cabo Verde to insecticides and identify the mechanisms of resistance. Samples of A. aegypti eggs were obtained at two different time periods (2012 and 2014), using ovitraps in different locations in Santiago Island to establish the parental population. F1 larvae were exposed to different concentrations of insecticides (Bacillus thuringiensis var israelensis (Bti), diflubenzuron and temephos) to estimate the lethal concentrations (LC90) and calculate the respective rate of resistance (RR90). Semi-field tests using temephos-ABATE(®) were performed to evaluate the persistence of the product. Bottle tests using female mosquitoes were carried out to determine the susceptibility to the adulticides malathion, cypermethrin and deltamethrin. Biochemical and molecular tests were performed to investigate the presence of metabolic resistance mechanisms, associated with the enzymes glutathione S-transferases (GSTs), esterases and mixed-function oxidases (MFO) and to detect mutations or alterations in the sodium channel and acetylcholinesterase genes. A. aegypti mosquitoes from Santiago exhibited resistance to deltamethrin, cypermethrin (mortality<80%) and temephos (RR90=4.4) but susceptibility to malathion (mortality≥98%), Bti and diflubenzuron. The low level of resistance to temephos did not affect the effectiveness of Abate(®). The enzymatic analysis conducted in 2012 revealed slight changes in the activities of GST (25%), MFO (18%), α-esterase (19%) and β-esterase (17%), but no significant changes in 2014. Target site resistance mutations were not detected. Our results suggest that the A. aegypti population from Santiago is resistant to two major

  13. A study on container breeding mosquitoes with special reference to Aedes (Stegomyia) aegypti and Aedes albopictus in Thiruvananthapuram district, India

    OpenAIRE

    K. Vijayakumar; T. K. Sudheesh Kumar; Zinia T Nujum; Farook Umarul; Anu Kuriakose

    2014-01-01

    Background & objectives: The district of Thiruvananthapuram reports the maximum number of cases of dengue in the state of Kerala. To determine the larval diversity, density and breeding site preferences of Aedes mosquitoes, during pre-monsoon and monsoon periods in urban and rural areas of Thiruvananthapuram district. Methods: Based on the daily reports of dengue cases, 70 clusters were identified in Thiruvananthapuram district. A cross-sectional larval survey was done in the domestic and ...

  14. Creams Formulated with Ocimum gratissimum L. and Lantana camara L. Crude Extracts and Fractions as Mosquito Repellents Against Aedes aegypti L. (Diptera: Culicidae)

    OpenAIRE

    Keziah, Ezeike Amarachi; Nukenine, Elias Nchiwan; Danga, Simon Pierre Yinyang; Younoussa, Lame; Esimone, Charles Okechukwu

    2015-01-01

    Mosquitoes are the most deadly vectors of parasites that cause diseases such as malaria, yellow fever, and filariasis. In view of the recent increased interest in developing plant origin insecticides as an alternative to chemical insecticides, the objective of this study was to determine the repellent activity of creams formulated with methanol crude extract (MCE), hexane fraction (HF), and ethyl acetate fractions (EAFs) of Ocimum gratissimum and Lantana camara leaves in single and combined a...

  15. Evaluation of fifteen local plants as larvicidal agents against an Indian strain of dengue fever mosquito, Aedes aegypti L. (Diptera: Culicidae)

    OpenAIRE

    Sarita eKumar; Naim eWahab; Monika eMishra; Radhika eWarikoo

    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 development of alternative strategies using eco-friendly, environmentally safe, bio-degradable plant products which are non-toxic to...

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

    OpenAIRE

    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-t...

  17. Control methods against invasive Aedes mosquitoes in Europe: a review.

    Science.gov (United States)

    Baldacchino, Frédéric; Caputo, Beniamino; Chandre, Fabrice; Drago, Andrea; della Torre, Alessandra; Montarsi, Fabrizio; Rizzoli, Annapaola

    2015-11-01

    Five species of invasive Aedes mosquitoes have recently become established in Europe: Ae. albopictus, Ae. aegypti, Ae. japonicus japonicus, Ae. koreicus and Ae. atropalpus. These mosquitoes are a serious nuisance for people and are also competent vectors for several exotic pathogens such as dengue and chikungunya viruses. As they are a growing public health concern, methods to control these mosquitoes need to be implemented to reduce their biting and their potential for disease transmission. There is a crucial need to evaluate methods as part of an integrated invasive mosquito species control strategy in different European countries, taking into account local Aedes infestations and European regulations. This review presents the control methods available or in development against invasive Aedes mosquitoes, with a particular focus on those that can be implemented in Europe. These control methods are divided into five categories: environmental (source reduction), mechanical (trapping), biological (e.g. copepods, Bacillus thuringiensis var. israelensis, Wolbachia), chemical (insect growth regulators, pyrethroids) and genetic (sterile insect technique and genetically modified mosquitoes). We discuss the effectiveness, ecological impact, sustainability and stage of development of each control method. PMID:26037532

  18. 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.

  19. Maya Index and Larva Density Aedes Aegypti Toward Dengue Infection

    OpenAIRE

    Sang G. Purnama; Tri Baskoro

    2012-01-01

    South Denpasar District was of there as with the highest dengue cases in Bali province. The number of mosquito breeding places and larvae density become risk factor that influenced the spreading of mosquitoes. Maya index was an indicator to measure the amount of waterreservoirs can be breeding places for mosquitoes. Knowing the relationship between maya index and density of larvae and pupae of Ae.aegypti toward dengue infection in South Denpasar District. The study was observational analytic ...

  20. Blood-feeding and immunogenic aedes aegypti saliva proteins

    OpenAIRE

    Surasombatpattana, Pornapat; Wasinpiyamongkol, L.; Patramool, Sirilaksana; Luplertlop, N.; Doucouré, Souleymane; Mouchet, François; Seveno, M.; Remoué, Franck; Demettre, E.; Brizard, Jean-Paul; Jouin, P.; Biron, D.G; F. Thomas; Missé, Dorothée

    2010-01-01

    Mosquito-transmitted pathogens pass through the insect's midgut (MG) and salivary gland (SG). What occurs in these organs in response to a blood meal is poorly understood, but identifying the physiological differences between sugar-fed and blood-fed (BF) mosquitoes could shed light on factors important in pathogens transmission. We compared differential protein expression in the MGs and SGs of female Aedes aegypti mosquitoes after a sugar- or blood-based diet. No difference was observed in th...

  1. 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.

  2. Mosquitoes feeding on insect larvae.

    Science.gov (United States)

    Harris, P; Riordan, D F; Cooke, D

    1969-04-11

    Caged Aedes aegypti and Culex tarsalis are attracted to insect larvae, engorge on their body fluids, and produce viable eggs. Attractiveness of the larvae is related to their size, shape, and color but not to their movement. The possibility that wild mosquitoes substitute insect hemolymph for vertebrate blood is discussed. PMID:5774191

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Dynamics of Aedes aegypti and Culex quinquefasciatus in septic tanks.

    Science.gov (United States)

    Mackay, Andrew J; Amador, Manuel; Diaz, Annette; Smith, Josh; Barrera, Roberto

    2009-12-01

    Aedes aegypti and Culex quinquefasciatus were found in large numbers emerging from septic tanks in southern Puerto Rico during the dry season. Previous studies suggested that Ae. aegypti uses subterranean aquatic habitats only during dry periods when surface containers do not have water. This research investigated whether septic tanks are alternative aquatic habitats that this mosquito uses during unfavorable times of the year, or whether Ae. aegypti uses this aquatic habitat throughout the year. To assess temporal change, exit traps were used to collect mosquitoes emerging from septic tanks in Playa/Playita, southern Puerto Rico, from November 2006 to October 2007. We also investigated the hypotheses that (1) the production of Ae. aegypti in septic tanks was larger than in surface containers and (2) adult mosquitoes emerging from septic tanks were larger than those emerging from surface containers. This study demonstrated that unsealed septic tanks produced large numbers of Ae. aegypti and Cx. quinquefasciatus throughout the year, without any significant relationship with rainfall. The number of adult Ae. aegypti emerging per day from septic tanks in each community was 3 to 9 times larger than those produced in surface containers. It was also demonstrated that Ae. aegypti emerging from septic tanks were significantly larger than those emerging from surface container habitats. It is recommended that dengue prevention programs include regular inspection and maintenance of septic tanks in communities lacking sewerage.

  5. PENGARUH "ICON IMPREGNATED CLOTH" TERHADAP POPULASI AEDES AEGYPTI DI DAERAH PERKOTAAN

    Directory of Open Access Journals (Sweden)

    Widiarti Widiarti

    2012-09-01

    Full Text Available An investigation to study the effect of ICON Impregnated Cloth on Aedes aegypty population in a semi wban area was conducted at Mapagan housing estate, Ungaran subdistrict, Semarang regency. Each house was provided with a cloth made from 65% polyester fibre and 35% combed cotton, 115 x 200 cm  in size. This cloth was impregnated with Icon at a dosage of 0,04 g a,i.lm and installed on the wall of dark, undisturbed area of bedroom, closest to mosquito breeding place. The entomological evaluation of indoor resting mosquitoes showed a significant reduction in the treated area during 2-3 months follow up whereas other parameters showed only a slight reduction, and was not significant compared to the control area.

  6. Solution Nuclear Magnetic Resonance Studies of Sterol Carrier Protein 2 Like 2 (SCP2L2) Reveal the Insecticide Specific Structural Characteristics of SCP2 Proteins in Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Singarapu, Kiran Kumar; Ahuja, Ashish; Potula, Purushotam Reddy; Ummanni, Ramesh

    2016-09-01

    Sterol carrier protein 2 like 2 from Aedes aegypti (AeSCP2L2) plays an important role in lipid transport in mosquitoes for its routine metabolic processes. Repeated unsuccessful attempts to crystallize ligand free SCP2L2 prompted us to undertake nuclear magnetic resonance (NMR) spectroscopy to determine its three-dimensional structure. We report here the three-dimensional structures and dynamics of apo-AeSCP2L2 and its complex with palmitate. The (15)N heteronuclear single-quantum coherence spectrum of apo-AeSCP2L2 displayed multiple peaks for some of the amide resonances, implying the presence of multiple conformations in solution, which are transformed to a single conformation upon formation of the complex with plamitate. The three-dimensional structures of apo-AeSCP2L2 and palmitated AeSCP2L2 reveal an α/β mixed fold, with five β-strands and four α-helices, very similar to the other SCP2 protein structures. Unlike the crystal structure of palmitated AeSCP2L2, both solution structures are monomeric. It is further confirmed by the rotational correlation times determined by NMR relaxation times (T1 and T2) of the amide protons. In addition, the palmitated AeSCP2L2 structure contains two palmitate ligands, bound in the binding pocket, unlike the three palmitates bound in the dimeric form of AeSCP2L2 in the crystals. The relaxation experiments revealed that complex formation significantly reduces the dynamics of the protein in solution.

  7. Solution Nuclear Magnetic Resonance Studies of Sterol Carrier Protein 2 Like 2 (SCP2L2) Reveal the Insecticide Specific Structural Characteristics of SCP2 Proteins in Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Singarapu, Kiran Kumar; Ahuja, Ashish; Potula, Purushotam Reddy; Ummanni, Ramesh

    2016-09-01

    Sterol carrier protein 2 like 2 from Aedes aegypti (AeSCP2L2) plays an important role in lipid transport in mosquitoes for its routine metabolic processes. Repeated unsuccessful attempts to crystallize ligand free SCP2L2 prompted us to undertake nuclear magnetic resonance (NMR) spectroscopy to determine its three-dimensional structure. We report here the three-dimensional structures and dynamics of apo-AeSCP2L2 and its complex with palmitate. The (15)N heteronuclear single-quantum coherence spectrum of apo-AeSCP2L2 displayed multiple peaks for some of the amide resonances, implying the presence of multiple conformations in solution, which are transformed to a single conformation upon formation of the complex with plamitate. The three-dimensional structures of apo-AeSCP2L2 and palmitated AeSCP2L2 reveal an α/β mixed fold, with five β-strands and four α-helices, very similar to the other SCP2 protein structures. Unlike the crystal structure of palmitated AeSCP2L2, both solution structures are monomeric. It is further confirmed by the rotational correlation times determined by NMR relaxation times (T1 and T2) of the amide protons. In addition, the palmitated AeSCP2L2 structure contains two palmitate ligands, bound in the binding pocket, unlike the three palmitates bound in the dimeric form of AeSCP2L2 in the crystals. The relaxation experiments revealed that complex formation significantly reduces the dynamics of the protein in solution. PMID:27508310

  8. Early trypsin activity is part of the signal transduction system that activates transcription of the late trypsin gene in the midgut of the mosquito, Aedes aegypti.

    Science.gov (United States)

    Barillas-Mury, C V; Noriega, F G; Wells, M A

    1995-02-01

    Trypsin activity during the first hours after feeding is essential to induce late trypsin gene expression. These results are consistent with the idea that free amino acids or other products released during digestion might be the initial signal for transcriptional activation of late trypsin. Besides early trypsin, some other factor(s) have to be translated for induction of late trypsin. This is the first case in which the proteolytic activity of a digestive enzyme is part of the signal transduction system which regulates expression of a second gene. The presence of two trypsins allows the mosquito to assess the quality of the meal and adjust the levels of late trypsin for a particular meal with remarkable flexibility. PMID:7711754

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

    Science.gov (United States)

    Peng, Rong; Fu, Qiang; Hong, Huazhu; Schwaegler, Tyler; Lan, Que

    2012-01-01

    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. PMID:23056538

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Midgut bacterial dynamics in Aedes aegypti.

    Science.gov (United States)

    Terenius, Olle; Lindh, Jenny M; Eriksson-Gonzales, Karolina; Bussière, Luc; Laugen, Ane T; Bergquist, Helen; Titanji, Kehmia; Faye, Ingrid

    2012-06-01

    In vector mosquitoes, the presence of midgut bacteria may affect the ability to transmit pathogens. We have used a laboratory colony of Aedes aegypti as a model for bacterial interspecies competition and show that after a blood meal, the number of species (culturable on Luria-Bertani agar) that coexist in the midgut is low and that about 40% of the females do not harbor any cultivable bacteria. We isolated species belonging to the genera Bacillus, Elizabethkingia, Enterococcus, Klebsiella, Pantoea, Serratia, and Sphingomonas, and we also determined their growth rates, antibiotic resistance, and ex vivo inhibition of each other. To investigate the possible existence of coadaptation between midgut bacteria and their host, we fed Ae. aegypti cohorts with gut bacteria from human, a frog, and two mosquito species and followed the bacterial population growth over time. The dynamics of the different species suggests coadaptation between host and bacteria, and interestingly, we found that Pantoea stewartii isolated from Ae. aegypti survive better in Ae. aegypti as compared to P. stewartii isolated from the malaria mosquito Anopheles gambiae. PMID:22283178

  12. The wMel strain of Wolbachia Reduces Transmission of Zika virus by Aedes aegypti

    Science.gov (United States)

    Aliota, Matthew T.; Peinado, Stephen A.; Velez, Ivan Dario; Osorio, Jorge E.

    2016-01-01

    Zika virus (ZIKV) is causing an explosive outbreak of febrile disease in the Americas. There are no effective antiviral therapies or licensed vaccines for this virus, and mosquito control strategies have not been adequate to contain the virus. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against other arboviruses. At present, it is unknown whether or not ZIKV can infect, disseminate, and be transmitted by Wolbachia-infected Ae. aegypti. Using Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for ZIKV. These results support the use of Wolbachia biocontrol as a multivalent strategy against Ae. aegypti-transmitted viruses. PMID:27364935

  13. The wMel strain of Wolbachia Reduces Transmission of Zika virus by Aedes aegypti.

    Science.gov (United States)

    Aliota, Matthew T; Peinado, Stephen A; Velez, Ivan Dario; Osorio, Jorge E

    2016-01-01

    Zika virus (ZIKV) is causing an explosive outbreak of febrile disease in the Americas. There are no effective antiviral therapies or licensed vaccines for this virus, and mosquito control strategies have not been adequate to contain the virus. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against other arboviruses. At present, it is unknown whether or not ZIKV can infect, disseminate, and be transmitted by Wolbachia-infected Ae. aegypti. Using Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for ZIKV. These results support the use of Wolbachia biocontrol as a multivalent strategy against Ae. aegypti-transmitted viruses. PMID:27364935

  14. Naturally Occurring Plant Compounds with Larvicidal Activity Against Aedes aegypti [Substâncias de Origem Vegetal com Atividade Larvicida Contra Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Walmir S. Garcez

    2013-01-01

    Full Text Available The mosquito Aedes aegypti is a vector that carries the arboviroses responsible for dengue and dengue hemorrhagic fevers, diseases which are considered as major worldwide public health problems. The most widely adopted strategy for decreasing the incidence of these diseasesresides in controlling the mosquito larvae population. The increasingly incidence of resistant mosquito populations due to the continuous use of synthetic insecticides, in addition to the publicconcern over environmental pollution and toxicity of the current commercial pesticides to non-target organisms, have stimulated the search for alternative methods for mosquito control. In this regard, plant-derived compounds have emerged as a promising efficient and environmentally safe tool for reducing the larval population ofAedes aegypti mosquitoes. This review provides a survey on naturally occurring plant compounds belonging to different classes of secondary metabolites which have been shown to be active against Aedes aegypti.

  15. Insecticide susceptibility status of Aedes aegypti and Anopheles stephensi larvae against temephos in Delhi, India

    OpenAIRE

    Singh, R. K.; P.K.Mittal; Gaurav Kumar; Dhiman, R.C.

    2014-01-01

    Temephos is used as a larvicide in urban areas in India to control the population of mosquito vectors viz. Anopheles stephensi and Aedes aegypti. The susceptibility status of Ae. aegypti and An. stephensi to temophos in various zones of Municipal Corporation of Delhi was evaluated using the WHO method for determining larval susceptibility test kit. Results revealed that the larval mortality of Ae. aegypti collected from different localities ranged between 64.88% to 98.22%. The highest mortali...

  16. Differential transcription profiles in Aedes aegypti detoxification genes following temephos selection

    OpenAIRE

    Saavedra-Rodriguez, Karla; Strode, Clare; FLORES, ADRIANA E.; Garcia-Luna, Selene; Reyes-Solis, Guadalupe; Ranson, Hilary; Hemingway, Janet; Black, William C.

    2013-01-01

    The mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance. Target site alteration in the acetylcholine esterase of this species has not being identified. Instead, we tracked changes in transcription of metabolic detoxification genes using the Ae. aegypti ‘Detox Chip’ microarray during five generations of te...

  17. Wolbachia Reduces the Transmission Potential of Dengue-Infected Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Yixin H Ye

    Full Text Available Dengue viruses (DENV are the causative agents of dengue, the world's most prevalent arthropod-borne disease with around 40% of the world's population at risk of infection annually. Wolbachia pipientis, an obligate intracellular bacterium, is being developed as a biocontrol strategy against dengue because it limits replication of the virus in the mosquito. The Wolbachia strain wMel, which has been introduced into the mosquito vector, Aedes aegypti, has been shown to invade and spread to near fixation in field releases. Standard measures of Wolbachia's efficacy for blocking virus replication focus on the detection and quantification of virus in mosquito tissues. Examining the saliva provides a more accurate measure of transmission potential and can reveal the extrinsic incubation period (EIP, that is, the time it takes virus to arrive in the saliva following the consumption of DENV viremic blood. EIP is a key determinant of a mosquito's ability to transmit DENVs, as the earlier the virus appears in the saliva the more opportunities the mosquito will have to infect humans on subsequent bites.We used a non-destructive assay to repeatedly quantify DENV in saliva from wMel-infected and Wolbachia-free wild-type control mosquitoes following the consumption of a DENV-infected blood meal. We show that wMel lengthens the EIP, reduces the frequency at which the virus is expectorated and decreases the dengue copy number in mosquito saliva as compared to wild-type mosquitoes. These observations can at least be partially explained by an overall reduction in saliva produced by wMel mosquitoes. More generally, we found that the concentration of DENV in a blood meal is a determinant of the length of EIP, saliva virus titer and mosquito survival.The saliva-based traits reported here offer more disease-relevant measures of Wolbachia's effects on the vector and the virus. The lengthening of EIP highlights another means, in addition to the reduction of infection

  18. 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.

  19. Heritability of attractiveness to mosquitoes.

    Directory of Open Access Journals (Sweden)

    G Mandela Fernández-Grandon

    Full Text Available Female mosquitoes display preferences for certain individuals over others, which is determined by differences in volatile chemicals produced by the human body and detected by mosquitoes. Body odour can be controlled genetically but the existence of a genetic basis for differential attraction to insects has never been formally demonstrated. This study investigated heritability of attractiveness to mosquitoes by evaluating the response of Aedes aegypti (=Stegomyia aegypti mosquitoes to odours from the hands of identical and non-identical twins in a dual-choice assay. Volatiles from individuals in an identical twin pair showed a high correlation in attractiveness to mosquitoes, while non-identical twin pairs showed a significantly lower correlation. Overall, there was a strong narrow-sense heritability of 0.62 (SE 0.124 for relative attraction and 0.67 (0.354 for flight activity based on the average of ten measurements. The results demonstrate an underlying genetic component detectable by mosquitoes through olfaction. Understanding the genetic basis for attractiveness could create a more informed approach to repellent development.

  20. Larvicidal activity of neem oil (Azadirachta indica formulation against mosquitoes

    Directory of Open Access Journals (Sweden)

    Dua Virendra K

    2009-06-01

    Full Text Available Abstract Background Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of botanical origin have been reported as useful for control of mosquitoes. Azadirachta indica (Meliaceae and its derived products have shown a variety of insecticidal properties. The present paper discusses the larvicidal activity of neem-based biopesticide for the control of mosquitoes. Methods Larvicidal efficacy of an emulsified concentrate of neem oil formulation (neem oil with polyoxyethylene ether, sorbitan dioleate and epichlorohydrin developed by BMR & Company, Pune, India, was evaluated against late 3rd and early 4th instar larvae of different genera of mosquitoes. The larvae were exposed to different concentrations (0.5–5.0 ppm of the formulation along with untreated control. Larvicidal activity of the formulation was also evaluated in field against Anopheles, Culex, and Aedes mosquitoes. The formulation was diluted with equal volumes of water and applied @ 140 mg a.i./m2 to different mosquito breeding sites with the help of pre calibrated knapsack sprayer. Larval density was determined at pre and post application of the formulation using a standard dipper. Results Median lethal concentration (LC50 of the formulation against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti was found to be 1.6, 1.8 and 1.7 ppm respectively. LC50 values of the formulation stored at 26°C, 40°C and 45°C for 48 hours against Ae. aegypti were 1.7, 1.7, 1.8 ppm while LC90 values were 3.7, 3.7 and 3.8 ppm respectively. Further no significant difference in LC50 and LC90 values of the formulation was observed against Ae. aegypti during 18 months storage period at room temperature. An application of the formulation at the rate of 140 mg a.i./m2 in different breeding

  1. Filarial worms reduce Plasmodium infectivity in mosquitoes.

    Directory of Open Access Journals (Sweden)

    Matthew T Aliota

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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

  2. 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.

  3. Genetically Modified Mosquito: Myth and Reality

    OpenAIRE

    Teh Su Yean; Koh Hock Lye; Yeap Kiew Lee

    2013-01-01

    Sterile Insect Technique (SIT) has been applied successfully in some agricultural pest control programs in the past, but in many cases, success has not been sustainable in the long run. Various attempts have been made to duplicate this limited success SIT application in agriculture to other areas of applications, particularly in vector control. For example, a recent mosquito control program has been initiated in Malaysia to eliminate dengue-mosquitoes Aedes aegypti by releasing large amount o...

  4. 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.

  5. 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.

  6. 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

    2015-12-01

    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

  7. Oviposition-Stimulant and Ovicidal Activities of Moringa oleifera Lectin on Aedes aegypti

    Science.gov (United States)

    Santos, Nataly Diniz de Lima; de Moura, Kézia Santana; Napoleão, Thiago Henrique; Santos, Geanne Karla Novais; Coelho, Luana Cassandra Breitenbach Barroso; Navarro, Daniela Maria do Amaral Ferraz; Paiva, Patrícia Maria Guedes

    2012-01-01

    Background 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. Methodology/Principal Findings 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 (pactivity 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. Conclusions/Significance 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. PMID:22970317

  8. 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 BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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

  9. Differential transcription profiles in Aedes aegypti detoxification genes after temephos selection.

    Science.gov (United States)

    Saavedra-Rodriguez, K; Strode, C; Flores, A E; Garcia-Luna, S; Reyes-Solis, G; Ranson, H; Hemingway, J; Black, W C

    2014-04-01

    The mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance. Target site alteration in the acetylcholine esterase of this species has not being identified. Instead, we tracked changes in transcription of metabolic detoxification genes using the Ae. aegypti 'Detox Chip' microarray during five generations of temephos selection. We selected for temephos resistance in three replicates in each of six collections, five from Mexico, and one from Peru. The response to selection was tracked in terms of lethal concentrations. Uniform upregulation was seen in the epsilon class glutathione-S-transferase (eGST) genes in strains from Mexico prior to laboratory selection, while eGSTs in the Iquitos Peru strain became upregulated after five generations of temephos selection. While expression of many carboxyl/cholinesterase esterase (CCE) genes increased with selection, no single esterase was consistently upregulated and this same pattern was noted in the cytochrome P450 monooxygenase (CYP) genes and in other genes involved in reduction or oxidation of xenobiotics. Bioassays using glutathione-S-transferase (GST), CCE and CYP inhibitors suggest that various CCEs instead of GSTs are the main metabolic mechanism conferring resistance to temephos. We show that temephos-selected strains show no cross resistance to permethrin and that genes associated with temephos selection are largely independent of those selected with permethrin in a previous study. PMID:24299217

  10. Differential transcription profiles in Aedes aegypti detoxification genes after temephos selection.

    Science.gov (United States)

    Saavedra-Rodriguez, K; Strode, C; Flores, A E; Garcia-Luna, S; Reyes-Solis, G; Ranson, H; Hemingway, J; Black, W C

    2014-04-01

    The mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance. Target site alteration in the acetylcholine esterase of this species has not being identified. Instead, we tracked changes in transcription of metabolic detoxification genes using the Ae. aegypti 'Detox Chip' microarray during five generations of temephos selection. We selected for temephos resistance in three replicates in each of six collections, five from Mexico, and one from Peru. The response to selection was tracked in terms of lethal concentrations. Uniform upregulation was seen in the epsilon class glutathione-S-transferase (eGST) genes in strains from Mexico prior to laboratory selection, while eGSTs in the Iquitos Peru strain became upregulated after five generations of temephos selection. While expression of many carboxyl/cholinesterase esterase (CCE) genes increased with selection, no single esterase was consistently upregulated and this same pattern was noted in the cytochrome P450 monooxygenase (CYP) genes and in other genes involved in reduction or oxidation of xenobiotics. Bioassays using glutathione-S-transferase (GST), CCE and CYP inhibitors suggest that various CCEs instead of GSTs are the main metabolic mechanism conferring resistance to temephos. We show that temephos-selected strains show no cross resistance to permethrin and that genes associated with temephos selection are largely independent of those selected with permethrin in a previous study.

  11. Resistance Status of Aedes aegypti to Cypermethrin through Susceptibility Method in Cimahi City

    Directory of Open Access Journals (Sweden)

    Yuneu Yuliasih

    2011-06-01

    Full Text Available Vector control of dengue usually doing by using insecticides, whether by government or insecticides used in household. Using to much insecticides for long time can caused resistence of mosquito. This research aim to know resistance status of Aedes aegypti from endemic rural in district Cimahi to cypermethrin (synthetic pyretroid. Resistance status knowing by susceptibility methods (WHO standard with using impregnated paper that containing cypermethrin 0.2% and 0.4%. Aedes aegypti spread by it for 15, 30, 45 and 60 minutes. Number of mortality count by percentage death mosquito in each time and each concentration of cypermethrin. Data interpreted by WHO standard, which percentage of death mosquito <80% is resistance, between 80-98% is tolerance and 99-100% is susceptible. Aedes aegypti from endemic rural in district Cimahi showed resistance of cypermethrin 0.2% and 0.4%. This result showed that all mosquito still alive after 15 minutes spreading by cypermethrin 0.2%, and only 6.7% mosquito death in cypermethrin 0.4%. After 30 minutes, death mosquito counted 46.7% in cypermethrin 0.2% and 73.3% in 0.4%. 46.7% mosquito was death in 45 and 60 minutes spreading by cypermethrin 0.2% and 73.3% in 0.4%. The result showed resistance ratio (RR50 of mosquito is 4.6. Aedes aegypti from endemic rural in district Cimahi showed a resistance to cypermethrin 0.2% and 0.4%.

  12. Aerial ULV application of Dibrom against Aedes aegypti in simulated urban and rural residences

    Science.gov (United States)

    Reaching endophilic Aedes aegypti mosquito vectors of dengue located in human residences with aerial ULV pesticide applications is a prominent complication in operational wide area public health mosquito control activities. We conducted separate trials with a military C-130 fixed wing aircraft fitte...

  13. Control methods against invasive Aedes mosquitoes in Europe : a review

    OpenAIRE

    Baldacchino, F; Caputo, B.; Chandre, Fabrice; Drago, A.; A. Della Torre; Montarsi, F.; Rizzoli, A.

    2015-01-01

    Five species of invasive Aedes mosquitoes have recently become established in Europe: Ae. albopictus, Ae. aegypti, Ae. japonicus japonicus, Ae. koreicus and Ae. atropalpus. These mosquitoes are a serious nuisance for people and are also competent vectors for several exotic pathogens such as dengue and chikungunya viruses. As they are a growing public health concern, methods to control these mosquitoes need to be implemented to reduce their biting and their potential for disease transmission. ...

  14. NO BUG: biobased mosquitoes repellent personal protective equipment (PPE)

    OpenAIRE

    Ciera, Lucy Wanjiru; Nierstrasz, Vincent; Van Langenhove, Lieva

    2012-01-01

    In tropical regions (South America, Asia and Africa) diseases like malaria and dengue cause many deaths. These diseases are transmitted through mosquitoes bites (Anopheles sp. and Aedes aegypti respectively). The current practice to protect against transmission of these diseases is by use of mosquito repellents. Common mosquito repellents used today are synthetic in nature and are suspected or have been proved to be harmful to the user and environment (e.g. DEET, DDT, dimethylphylphthalate, p...

  15. Cues of mosquito host finding and oviposition site selection

    OpenAIRE

    Afify, Ali

    2014-01-01

    The aim of this work was to study odor cues that affect mosquito host seeking and oviposition behavior. Due to the vastness (and sometimes contradictions) of mosquito oviposition cues available in literature, I started by reviewing these cues, their source in nature, and their role in mosquito oviposition. Then, I tested the oviposition response of Aedes aegypti towards the contradictory oviposition odor p-cresol and its isomer m-cresol in different situations.p-cresol showed an oviposition d...

  16. Stage-Structured Population Dynamics of AEDES AEGYPTI

    Science.gov (United States)

    Yusoff, Nuraini; Budin, Harun; Ismail, Salemah

    Aedes aegypti is the main vector in the transmission of dengue fever, a vector-borne disease affecting world population living in tropical and sub-tropical countries. Better understanding of the dynamics of its population growth will help in the efforts of controlling the spread of this disease. In looking at the population dynamics of Aedes aegypti, this paper explored the stage-structured modeling of the population growth of the mosquito using the matrix population model. The life cycle of the mosquito was divided into five stages: eggs, larvae, pupae, adult1 and adult2. Developmental rates were obtained for the average Malaysian temperature and these were used in constructing the transition matrix for the matrix model. The model, which was based only on temperature, projected that the population of Aedes aegypti will blow up with time, which is not realistic. For further work, other factors need to be taken into account to obtain a more realistic result.

  17. Vectorial capacity of Aedes aegypti for dengue virus type 2 is reduced with co-infection of Metarhizium anisopliae.

    Directory of Open Access Journals (Sweden)

    Javier A Garza-Hernández

    Full Text Available BACKGROUND: Aedes aegypti, is the major dengue vector and a worldwide public health threat combated basically by chemical insecticides. In this study, the vectorial competence of Ae. aegypti co-infected with a mildly virulent Metarhizium anisopliae and fed with blood infected with the DENV-2 virus, was examined. METHODOLOGY/PRINCIPAL FINDINGS: The study encompassed three bioassays (B. In B1 the median lethal time (LT50 of Ae. aegypti exposed to M. anisopliae was determined in four treatments: co-infected (CI, single-fungus infection (SF, single-virus infection (SV and control (C. In B2, the mortality and viral infection rate in midgut and in head were registered in fifty females of CI and in SV. In B3, the same treatments as in B1 but with females separated individually were tested to evaluate the effect on fecundity and gonotrophic cycle length. Survival in CI and SF females was 70% shorter than the one of those in SV and control. Overall viral infection rate in CI and SV were 76 and 84% but the mortality at day six post-infection was 78% (54% infected and 6% respectively. Survivors with virus in head at day seven post-infection were 12 and 64% in both CI and SV mosquitoes. Fecundity and gonotrophic cycle length were reduced in 52 and 40% in CI compared to the ones in control. CONCLUSION/SIGNIFICANCE: Fungus-induced mortality for the CI group was 78%. Of the survivors, 12% (6/50 could potentially transmit DENV-2, as opposed to 64% (32/50 of the SV group, meaning a 5-fold reduction in the number of infective mosquitoes. This is the first report on a fungus that reduces the vectorial capacity of Ae. aegypti infected with the DENV-2 virus.

  18. Pengaruh Modifikasi Ovitrap terhadap Kepadatan Nyamuk Aedes aegypti di Kelurahan Siopat Suhu Kota Pematang Siantar

    OpenAIRE

    Hasibuan, Lasni Fitryani

    2015-01-01

    The outbreak incident of dengue hemorrhagic fever (DHF) still frequently occurs in various areas in Indonesia. One of the ways of controlling theAedesAegypti mosquitos that is successful in decreasing vector density in several countries is the use of egg trap (ovitrap). Ovitrap is a device to attract mosquitos to lay their eggs in it. The purpose of this study was to test the influence of Ovitrap modification on the density of Aedes aegypti mosquitos by looking at the difference between Co...

  19. The suitability of restriction fragment length polymorphism markers for evaluating genetic diversity among and synteny between mosquito species.

    Science.gov (United States)

    Severson, D W; Mori, A; Zhang, Y; Christensen, B M

    1994-04-01

    Restriction fragment length polymorphism (RFLP) markers derived from the yellow fever mosquito, Aedes aegypti, were used in hybridizations to genomic DNA of the following mosquito species: Ae. albopictus, Ae. togoi, Armigeres subalbatus, Culex pipiens, and Anopheles gambiae. Interspecific hybridization with Ae. aegypti probes varied from 50% (An. gambiae) to 100% (Ae. albopictus) under high stringency conditions. We demonstrated the usefulness of using RFLP profiles to examine genetic diversity between mosquito populations; Ae. aegypti RFLP markers were used to examine genetic relatedness between 10 laboratory strains of Ae. aegypti as well as between nine populations representing four Cx. pipiens subspecies. These results indicate that many Ae. aegypti RFLP markers should have direct applicability in gaining a better understanding of genome structure in other mosquito species, including RFLP linkage mapping and determinations of genetic relatedness among field populations. PMID:7909414

  20. Iron Loaded Ferritin Secretion and Inhibition by CI-976 in Aedes aegypti larval cells

    OpenAIRE

    Geiser, Dawn L.; Shen, Meng-Chieh; Mayo, Jonathan J.; Winzerling, Joy J.

    2009-01-01

    Ferritin is a multimer of 24 subunits of heavy and light chains. In mammals, iron taken into cells is stored in ferritin or incorporated into iron-containing proteins. Very little ferritin is found circulating in mammalian serum; most is retained in the cytoplasm. Female mosquitoes, such as Aedes aegypti (yellow fever mosquito, Diptera), require a blood meal for oogenesis. Mosquitoes receive a potentially toxic level of iron in the blood meal which must be processed and stored. We demonstrate...

  1. Open Field Release of Genetically Engineered Sterile Male Aedes aegypti in Malaysia

    OpenAIRE

    Renaud Lacroix; McKemey, Andrew R.; Norzahira Raduan; Lim Kwee Wee; Wong Hong Ming; Teoh Guat Ney; Siti Rahidah A A; Sawaluddin Salman; Selvi Subramaniam; Oreenaiza Nordin; Norhaida Hanum A T; Chandru Angamuthu; Suria Marlina Mansor; Lees, Rosemary S.; Neil Naish

    2012-01-01

    BACKGROUND: Dengue is the most important mosquito-borne viral disease. In the absence of specific drugs or vaccines, control focuses on suppressing the principal mosquito vector, Aedes aegypti, yet current methods have not proven adequate to control the disease. New methods are therefore urgently needed, for example genetics-based sterile-male-release methods. However, this requires that lab-reared, modified mosquitoes be able to survive and disperse adequately in the field. METHODOLOGY/PRINC...

  2. Open Field Release of Genetically Engineered Sterile Male Aedes aegypti in Malaysia

    OpenAIRE

    Lacroix, Renaud; McKemey, Andrew R.; Raduan, Norzahira; Kwee Wee, Lim; Hong Ming, Wong; Guat Ney, Teoh; Rahidah A.A., Siti; Salman, Sawaluddin; Subramaniam, Selvi; Nordin, Oreenaiza; Hanum A.T., Norhaida; Angamuthu, Chandru; Marlina Mansor, Suria; Lees, Rosemary S; Naish, Neil

    2012-01-01

    Background Dengue is the most important mosquito-borne viral disease. In the absence of specific drugs or vaccines, control focuses on suppressing the principal mosquito vector, Aedes aegypti, yet current methods have not proven adequate to control the disease. New methods are therefore urgently needed, for example genetics-based sterile-male-release methods. However, this requires that lab-reared, modified mosquitoes be able to survive and disperse adequately in the field. Methodology/Princi...

  3. Structure-activity relationship studies on derivatives of eudesmanolides from Inula helenium as toxicants against Aedes aegypti larvae and adults.

    Science.gov (United States)

    Cantrell, Charles L; Pridgeon, Julia W; Fronczek, Frank R; Becnel, James J

    2010-07-01

    An Aedes aegypti larval toxicity bioassay was performed on compounds representing many classes of natural compounds including polyacetylenes, phytosterols, flavonoids, sesquiterpenoids, and triterpenoids. Among these compounds, two eudesmanolides, alantolactone, and isoalantolactone showed larvicidal activities against Ae. aegypti and, therefore, were chosen for further structure-activity relationship study. In this study, structural modifications were performed on both alantolactone and isoalantolactone in an effort to understand the functional groups necessary for maintaining and/or increasing its activity, and to possibly lead to more effective insect-control agents. All parent compounds and synthetic modification reaction products were evaluated for their toxic activities against Ae. aegypti larvae and adults. Structure modifications included epoxidations, reductions, catalytic hydrogenations, and Michael additions to the alpha,beta-unsaturated lactones. None of the synthetic isomers synthesized and screened against Ae. aegypti larvae were more active than isoalantolactone itself which had an LC(50) value of 10.0 microg/ml. This was not the case for analogs of alantolactone for which many of the analogs had larvicidal activities ranging from 12.4 to 69.9 microg/ml. In general, activity trends observed from Ae. aegypti larval screening were not consistent with observations from adulticidal screening. The propylamine Michael addition analog of alantolactone was the most active adulticide synthesized with an LC(50) value of 1.07 microg/mosquito. In addition, the crystal structures of both alantolactone and isoalantolactone were determined using CuK(alpha) radiation, which allowed their absolute configurations to be determined based on resonant scattering of the light atoms. PMID:20658657

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. An extraovarian protein accumulated in mosquito oocytes is a carboxypeptidase activated in embryos

    Energy Technology Data Exchange (ETDEWEB)

    Wenlong Cho; Deitsch, K.W.; Raikhel, A.S. (Michigan State Univ., East Lansing (United States))

    1991-12-01

    The authors report a phenomenon previously unknown for oviparous animals; in Aedes aegypti mosquitoes a serine carboxypeptidase is synthesized extraovarially and then internalized by oocytes. The cDNA encoding mosquito vitellogenic carboxypeptidase (VCP) was cloned and sequenced. The VCP cDNA hybridizes to a 1.5-kilobase mRNA present only in the fat body of vitellogenic females. The deduced amino acid sequence of VCP shares significant homology with members of the serine carboxypeptidase family. Binding assays using a serine protease inhibitor, ({sup 3}H)diisopropyl fluorophosphate, showed that VCP is activated in eggs at the onset of embryonic development. Activation of VCP is associated with the reduction in its size from 53 kDa (inactive proenzyme) to 48 kDa (active enzyme). The active, 48-kDa, form of VCP is maximally present at the middle of embryonic development and disappears by the end.

  7. 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.

  8. PENGARUH SUMBER NUTRISI TERHADAP UMUR VEKTOR DEMAM BERDARAH DENGUE Aedes aegypti DI LABORATORIUM

    Directory of Open Access Journals (Sweden)

    Riyani Setiyaningsih

    2011-12-01

    Full Text Available ENGLISHAedes aegypti is a major vector of DHF in several areas of Indonesia. The longetivity of Ae. aegypti female mosquitoes could be up to 10 days nature. Whereas in laboratorium condition, they could survive for 2 months by feeding on sugar water and blood. Based on that background, this research is intended to find out the influence of the nutrition sources. Such as sugar solution, vitamin solution and blood of rabbit. As a control, nutrition will not be given at all. The death procentage of the mosquitoes was examined every day until the death reached up to 100%. The result showed that there was no significant difference between giving variations of sugar solution, vitamin and blood toward the longivity at Ae. aegypti. The 100% mortality of female mosquitos, fed on sugar solution, vitamin, blood and the control were observed on 22 days, 20 days, 18 days and 13 daysINDONESIAAedes aegypti merupakan vektor utama Demam Berdarah Dangue ( DBD di beberapa darah di Indonesia. Umur nyamuk Ae. aegypti betina di alam dapat mencapai 10 hari, sedangkan pada kondisi laboratorium Ae. aegypti dapat bertahan hidup selama 2 bulan dengan menggunakan nutrisi berupa air gula dan darah. Penelitian ini bertujuan untuk mengetahui pengaruh sumber nutrisi yang berupa larutan gula, larutan vitamin (provit dan darah terhadap umur nyamuk Ae. aegypti. Nyamuk Ae. aegypti jantan dan betina di masukkan di dalam gelas plastik. Nyamuk Ae. aegypti diberikan beberapa variasi perlakuan yaitu nutrisi yang berupa larutan gula, larutan vitamin (provit, dan darah marmut. Sebagai kontrol tidak diberikan nutrisi apapun. Persentase kematian nyamuk diamati tiap hari sampai kematian mencapai 100%. Hasil penelitian menunjukkan bahwa tidak ada perbedaan yang nyata antara pemberian variasi nutrisi larutan gula, vitamin, dan darah terhadap umur Ae. aegypti. Kematian 100% pada nyamuk betina yang diberi nutrisi gula, vitamin, darah , dan kontrol masing-masing terjadi setelah, 22 hari, 20 hari

  9. 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. PMID:23923330

  10. Effect of phenobarbital on inducing insecticide tolerance and esterase changes in Aedes aegypti (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Sousa-Polezzi

    2004-01-01

    Full Text Available The effect of phenobarbital (PB on the induction of tolerance to the organophosphorous insecticide temephos (TE was investigated in Aedes aegypti L4 larvae submitted to two different PB-treatments:(1 continuous treatment from the egg to the larval L4 stage and (2 discontinuous treatment in which L4 larvae were exposed for 30 h. Mosquitoes from two Brazilian cities were studied: São José do Rio Preto (SJ in São Paulo State and Goiânia (GO in Goiás State. According to criterions established by World Health Organization (WHO mosquitoes from SJ are organophosphate-susceptible while mosquitoes from GO are organophosphate-resistant. For both SJ and GO larvae the two different PB-treatments resulted in significantly increased tolerance (measured by reduced mortality to 0.01mg/L TE while for larvae exposed to 0.02 mg/L TE only continuous PB-treatment resulted in significantly increased TE-tolerance. The reduction of mortality rate was greater in SJ larvae than in GO larvae, confirming data from other organisms indicating that the effect of PB is more pronounced in susceptible strains. To test if oxidase enzymes were involved in PB-induced tolerance we treated PB-pretreated SJ and GO larvae with the oxidase inhibitor piperonyl butoxide (PBO before exposure to TE and observed increased (rather than decreased tolerance, suggesting that oxidases are not involved in the tolerance process and that PB and PBO can act in concert or synergistically. Esterase patterns of PB-pretreated larvae indicated that the cholinesterases EST-13 and EST-14 are involved in the PB-induced TE- tolerance, reinforcing a previous study carried out in our laboratory which suggested that increased esterase synthesis is the mechanism responsible for the development of insecticide resistance in Aedes aegypti.

  11. Molecular characterization of Aedes aegypti (L. (Diptera: Culicidae of Easter Island based on analysis of the mitochondrial ND4 gene

    Directory of Open Access Journals (Sweden)

    Claudia Andrea Núñez

    2016-06-01

    Full Text Available ABSTRACT Aedes aegypti mosquitoes are the main vector of viruses Dengue, Zika and Chikungunya. Shortly after the first report of the dengue vector Ae. aegypti in Easter Island (Rapa Nui in late 2000, the first disease outbreak dengue occurred. Viral serotyping during the 2002 outbreak revealed a close relationship with Pacific DENV-1 genotype IV viruses, supporting the idea that the virus most likely originated in Tahiti. Mitochondrial NADH dehydrogenase subunit 4 (ND4 DNA sequences generated from 68 specimens of Ae. aegypti from Easter Island reporting a unique finding of a single maternal lineage of Ae. aegypti on Easter Island.

  12. Mosquitocidal properties of Oxystelma esculentum (Asclepiadaceae-Indian medicinal plant tested against Ades aegypti (Linn. (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Kuppusamy Elumalai

    2015-04-01

    Full Text Available Objective: To evaluate the mosquitocidal activities of various solvent extract of Oxystelma esculentum (O. esculentum against the medically important dengue vector mosquito, Aedes aegypti (Ae. aegypti L. Methods: A total of 25 early third instar larvae of Ae. aegypti were exposed to various concentrations (60-300 mg/L and were assayed in the laboratory by using the protocol of World Health Organization, 2005; the 24 h LC50 values of the O. esculentum leaf extract was determined by probit analysis. The ovicidal activity was determined against the freshly laid eggs of Ae. aegypti to various concentrations ranging from 50-300 mg/L under laboratory conditions. The pupicidal activity was determined against pupae of Ae. aegypti to various concentrations ranging from 70-280 mg/L after 24 h of exposure to the concern extract. The repellent efficacy was determined against adult female mosquito species at 1.0, 2.0 and 3.0 mg/ cm2 under laboratory conditions. Results: The LC50 value of methanol extract of O. esculentum against 3rd instar larvae of Ae. aegypti was 125.82 mg/L. The same extract showed 100% egg mortality at 250 mg/L and also pupicidal activity observed against the pupae of Ae. aegypti at 280 mg/L. Conclusions: The present results suggest that the O. esculentum leaf extracts provided an excellent, potential phytopesticide for controlling Ae. aegypti mosquito.

  13. Mosquitocidal properties of Oxystelma esculentum (Asclepiadaceae)-Indian medicinal plant tested against Ades aegypti (Linn.) (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Kuppusamy Elumalai; Kaliyamoorthy Krishnappa

    2015-01-01

    Objective: To evaluate the mosquitocidal activities of various solvent extract of Oxystelma esculentum (O. esculentum) against the medically important dengue vector mosquito, Aedes aegypti (Ae. aegypti) L. Methods: A total of 25 early third instar larvae of Ae. aegypti were exposed to various concentrations (60-300 mg/L) and were assayed in the laboratory by using the protocol of World Health Organization, 2005; the 24 h LC50 values of the O. esculentum leaf extract was determined by probit analysis. The ovicidal activity was determined against the freshly laid eggs of Ae. aegypti to various concentrations ranging from 50-300 mg/L under laboratory conditions. The pupicidal activity was determined against pupae of Ae. aegypti to various concentrations ranging from 70-280 mg/L after 24 h of exposure to the concern extract. The repellent efficacy was determined against adult female mosquito species at 1.0, 2.0 and 3.0 mg/cm2 under laboratory conditions. Results: The LC50 value of methanol extract of O. esculentum against 3rd instar larvae of Ae. aegypti was 125.82 mg/L. The same extract showed 100% egg mortality at 250 mg/L and also pupicidal activity observed against the pupae of Ae. aegypti at 280 mg/L. Conclusions: The present results suggest that the O. esculentum leaf extracts provided an excellent, potential phytopesticide for controlling Ae. aegypti mosquito.

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

    Science.gov (United States)

    Richard, Vaea; Paoaafaite, Tuterarii; Cao-Lormeau, Van-Mai

    2016-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance 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. PMID:27654962

  15. PATOGENITAS CENDAWAN BEAUVERIA BASSIANA TERHADAP LARVA NYAMUK AEDES AEGYPTI DAN CULEX PIPIENS QUINQUEFASCIATUS DI LABORATORIUM

    Directory of Open Access Journals (Sweden)

    Amrul Munif

    2012-09-01

    Full Text Available The capability of Beauveria bassiana fungus to kill mosquito larvae was challenged with Aedes aegypti and Culex pipiens quinquefasciatus in a study conducted at the entomology laboratory of the Health Ecology Research Centre. Cx. p. quinquefeasciatus was more sensitive compared to Ae. aegypti to the B. bassiana strain from Sukamandi (West Java, which is probably due to the mosquitoes behaviour and conidiospore larvacidal effect. Conidia dust application, with a dosage of 2.2 mglliter, to water surface, within 48 hours was able to kill almost all the Cx. p. quinquefasciatus. However a dosage of 4 mglliter was required to kill all the Ae.aegypti. And a dosage of 1.3 mg conidiospore I liter is able to kill 50% Cx. p. quinquefasciatus. It seems that B. bassiana has greater capability to eradicate Cx. p. quinquefasciatus compared to Ae. aegypti

  16. Monooxygenase activitity in Aedes aegypti population in Tembalang subdistrict, Semarang city

    Directory of Open Access Journals (Sweden)

    Dyah Widiastuti

    2015-06-01

    Full Text Available 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

  17. Oral Susceptibility to Yellow Fever Virus of Aedes aegypti from Brazil

    Directory of Open Access Journals (Sweden)

    Ricardo Lourenço-de-Oliveira

    2002-04-01

    Full Text Available The oral susceptibility to yellow fever virus was evaluated in 23 Aedes aegypti samples from Brazil. Six Ae. aegypti samples from Africa, America and Asia were also tested for comparison. Mosquito samples from Asia showed the highest infection rates. Infection rates for the Brazilian Ae. aegypti reached 48.6%, but were under 13% in 60% of sample tested. We concluded that although the low infection rates estimated for some Brazilian mosquito samples may not favor the establishment of urban cycle of yellow fever in some parts of the country, the founding of Ae. aegypti of noteworthy susceptibility to the virus in cities located in endemic and transition areas of sylvatic yellow fever, do pose a threat of the re-emergence of the urban transmission of the disease in Brazil.

  18. 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...

  19. 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

  20. PENGARUH PENYULUHAN TERHADAP TINGKAT PENGET MASYARAKAT DAN KEPADATAN Aedes aegypti DI KECAMATAN BAYAH, PROVINSI BANTEN

    OpenAIRE

    Agnes Kurniawan; Rawina Winita; Saleha Sungkar

    2010-01-01

    The Effect of Health Education to Community Knowledge and Aedes aegypti Density in Bayah Subdistrict, Banten Province. Dengue Haemorrhagic Fever (DHF) is a public health problem in Bayah, Banten Province thus, control of mosquitoes breeding sites (CMBS) and health education is necessary. This study aimed to evaluate the effect of health education on people’s level of knowledge on CMBS and the density of Ae. aegypti. This study involved 106 villagers from Bayah in August (pretest) and October...

  1. Spatial and temporal country-wide survey of temephos resistance in Brazilian populations of Aedes aegypti

    OpenAIRE

    Mateus Chediak; Fabiano G Pimenta Jr; Giovanini E Coelho; Ima A Braga; José Bento P Lima; Karina Ribeiro LJ Cavalcante; Lindemberg C. Sousa; Maria Alice V Melo-Santos; Maria de Lourdes da G Macoris; Ana Paula de Araújo; Ayres, Constância Flávia J; Maria Teresa M Andrighetti; Ricristhi Gonçalves de A Gomes; Campos, Kauara B; Raul Narciso C Guedes

    2016-01-01

    The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in...

  2. Resistance Status of Aedes aegypti to Cypermethrin through Susceptibility Method in Cimahi City

    OpenAIRE

    Yuneu Yuliasih; Rina Marina; Mara Ipa; Firda Yanuar Pradani

    2011-01-01

    Vector control of dengue usually doing by using insecticides, whether by government or insecticides used in household. Using to much insecticides for long time can caused resistence of mosquito. This research aim to know resistance status of Aedes aegypti from endemic rural in district Cimahi to cypermethrin (synthetic pyretroid). Resistance status knowing by susceptibility methods (WHO standard) with using impregnated paper that containing cypermethrin 0.2% and 0.4%. Aedes aegypti spread by ...

  3. Socioeconomic and Ecological Factors Influencing Aedes aegypti Prevalence, Abundance, and Distribution in Dhaka, Bangladesh

    OpenAIRE

    Dhar-Chowdhury, Parnali; Haque, C. Emdad; Lindsay, Robbin; Hossain, Shakhawat

    2016-01-01

    This study examined household risk factors and prevalence, abundance, and distribution of immature Aedes aegypti and Aedes albopictus, and their association with socioeconomic and ecological factors at urban zonal and household levels in the city of Dhaka, Bangladesh. During the 2011 monsoon, 826 households in 12 randomly selected administrative wards were surveyed for vector mosquitoes. Results revealed that the abundance and distribution of immature Ae. aegypti and Ae. albopictus, and pupae...

  4. Changing Domesticity of Aedes aegypti in Northern Peninsular Malaysia: Reproductive Consequences and Potential Epidemiological Implications

    OpenAIRE

    Saifur, Rahman G. M.; Dieng, Hamady; Hassan, Ahmad Abu; Salmah, Md Rawi Che; Satho, Tomomitsu; Miake, Fumio; Hamdan, Ahmad

    2012-01-01

    Background The domestic dengue vector Aedes aegypti mosquitoes breed in indoor containers. However, in northern peninsular Malaysia, they show equal preference for breeding in both indoor and outdoor habitats. To evaluate the epidemiological implications of this peridomestic adaptation, we examined whether Ae. aegypti exhibits decreased survival, gonotrophic activity, and fecundity due to lack of host availability and the changing breeding behavior. Methodology/Principal Findings This yearlon...

  5. 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

  6. 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)

    Suresh, Udaiyan; Murugan, Kadarkarai; Benelli, Giovanni; Nicoletti, Marcello; Barnard, Donald R; Panneerselvam, Chellasamy; Kumar, Palanisamy Mahesh; Subramaniam, Jayapal; Dinesh, Devakumar; Chandramohan, Balamurugan

    2015-04-01

    Mosquitoes are vectors of devastating pathogens and parasites, causing millions of deaths every year. Dengue is a mosquito-borne viral infection found in tropical and subtropical regions around the world. Recently, transmission has strongly increased in urban and semiurban areas, becoming a major international public health concern. Aedes aegypti (Diptera: Culicidae) is the primary vector of dengue. The use of synthetic insecticides to control Aedes mosquitoes lead to high operational costs and adverse nontarget effects. In this scenario, eco-friendly control tools are a priority. We proposed a novel method to synthesize silver nanoparticles using the aqueous leaf extract of Phyllanthus niruri, a cheap and nontoxic material. The UV-vis spectrum of the aqueous medium containing silver nanostructures showed a peak at 420 nm corresponding to the surface plasmon resonance band of nanoparticles. SEM analyses of the synthesized nanoparticles showed a mean size of 30-60 nm. EDX spectrum showed the chemical composition of the synthesized nanoparticles. XRD highlighted that the nanoparticles are crystalline in nature with face-centered cubic geometry. Fourier transform infrared spectroscopy (FTIR) of nanoparticles exhibited prominent peaks 3,327.63, 2,125.87, 1,637.89, 644.35, 597.41, and 554.63 cm(-1). In laboratory assays, the aqueous extract of P. niruri was toxic against larval instars (I-IV) and pupae of A. aegypti. LC50 was 158.24 ppm (I), 183.20 ppm (II), 210.53 ppm (III), 210.53 ppm (IV), and 358.08 ppm (pupae). P. niruri-synthesized nanoparticles were highly effective against A. aegypti, with LC50 of 3.90 ppm (I), 5.01 ppm (II), 6.2 ppm (III), 8.9 ppm (IV), and 13.04 ppm (pupae). In the field, the application of silver nanoparticles (10 × LC50) lead to A. aegypti larval reduction of 47.6%, 76.7% and 100%, after 24, 48, and 72 h, while the P. niruri extract lead to 39.9%, 69.2 % and 100 % of reduction, respectively. In adulticidal experiments, P. niruri extract

  7. Distribution of Voltage-Gated Sodium Channel (Nav) Alleles among the Aedes aegypti Populations In Central Java Province and Its Association with Resistance to Pyrethroid Insecticides

    OpenAIRE

    Sayono Sayono; Anggie Puspa Nur Hidayati; Sukmal Fahri; Didik Sumanto; Edi Dharmana; Suharyo Hadisaputro; Puji Budi Setia Asih; Din Syafruddin

    2016-01-01

    The emergence of insecticide resistant Aedes aegypti mosquitoes has hampered dengue control efforts. WHO susceptibility tests, using several pyrethroid compounds, were conducted on Ae. aegypti larvae that were collected and raised to adulthood from Semarang, Surakarta, Kudus and Jepara in Java. The AaNa V gene fragment encompassing kdr polymorphic sites from both susceptible and resistant mosquitoes was amplified, and polymorphisms were associated with the resistant phenotype. The insecticide...

  8. 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)

  9. Occurrence of Toxorhynchites guadeloupensis (Dyar and Knab) in oviposition trap of Aedes aegypti (L.) (Diptera: Culicidae)

    International Nuclear Information System (INIS)

    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)

  10. Aedes aegypti on Madeira Island (Portugal: genetic variation of a recently introduced dengue vector

    Directory of Open Access Journals (Sweden)

    Goncalo Seixas

    2013-01-01

    Full Text Available 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.

  11. 具有不育控制的埃及伊蚊种群模型的全局动态%Global Dynamics of a Mathematical Model for the Control of Aedes aegypti Mosquitoes by the Sterile Insect Release Technique

    Institute of Scientific and Technical Information of China (English)

    聂玉稳; 刘贤宁; 宋杨

    2012-01-01

    给出了一个描述具有不育雄蚊作为生物控制的埃及伊蚊种群动力系统的模型.研究了边界平衡点及正平衡点存在和稳定的条件,得到了当正平衡点不存在时,边界平衡点全局渐近稳定的条件,即投放不育雄蚊使得野生蚊子种群灭亡的充分条件.%In this paper, a mathematical model is presented describing the dynamics of mosquito population with biological control by sterile male mosquito releasing. The existence and stability of the boundary and positive equilibria are investigated. We obtain the conditions for the global asymptotical stability of the boundary equilibrium when the positive equilibria do not exist, that is, the threshold for making wild mosquito population extinct by releasing sterile male mosquitoes.

  12. PEMETAAN, KARAKTERISTIK HABITAT DAN STATUS RESISTENSI Aedes aegypti DI KOTA BANJARMASIN KALIMANTAN SELATAN

    OpenAIRE

    Safitri -

    2013-01-01

    ABSTRACT. Control program of Aedes aegypti in Banjarmasin by using Malation has been done since almost 15 years ago. Related to this, a study about distribution and resistence of Ae.aegypti inBanjarmasin has been done. Ae.aegypti shown to be in almost all area in Banjarmasin, with water container in the bathroom and in the house are more liked. Susceptibility test showed thatthis mosquito was resistence to Malation 0,8%. Therefor, a policy to change this type of insecticide is needed.Key word...

  13. Aedes aegypti Control Strategies in Brazil: Incorporation of New Technologies to Overcome the Persistence of Dengue Epidemics

    OpenAIRE

    Helena R. C. Araújo; Carvalho, Danilo O.; Ioshino, Rafaella S.; Costa-da-Silva, André L.; Capurro, Margareth L.

    2015-01-01

    Dengue is considered to be the most important mosquito-borne viral disease in the world. The Aedes aegypti mosquito, its vector, is highly anthropophilic and is very well adapted to urban environments. Although several vaccine candidates are in advanced stages of development no licensed dengue vaccine is yet available. As a result, controlling the spread of dengue still requires that mosquitoes be targeted directly. We review the current methods of dengue vector control focusing on recent tec...

  14. Binding of a fluorescence reporter and a ligand to an odorant-binding protein of the yellow fever mosquito, Aedes aegypti [v2; ref status: indexed, http://f1000r.es/4yp

    Directory of Open Access Journals (Sweden)

    Gabriel M. Leal

    2015-01-01

    Full Text Available Odorant-binding proteins (OBPs, also named pheromone-binding proteins when the odorant is a pheromone, are essential for insect olfaction. They solubilize odorants that reach the port of entry of the olfactory system, the pore tubules in antennae and other olfactory appendages. Then, OBPs transport these hydrophobic compounds through an aqueous sensillar lymph to receptors embedded on dendritic membranes of olfactory receptor neurons. Structures of OBPs from mosquito species have shed new light on the mechanism of transport, although there is considerable debate on how they deliver odorant to receptors. An OBP from the southern house mosquito, Culex quinquefasciatus, binds the hydrophobic moiety of a mosquito oviposition pheromone (MOP on the edge of its binding cavity. Likewise, it has been demonstrated that the orthologous protein from the malaria mosquito binds the insect repellent DEET on a similar edge of its binding pocket. A high school research project was aimed at testing whether the orthologous protein from the yellow fever mosquito, AaegOBP1, binds DEET and other insect repellents, and MOP was used as a positive control. Binding assays using the fluorescence reporter N-phenyl-1-naphtylamine (NPN were inconclusive. However, titration of NPN fluorescence emission in AaegOBP1 solution with MOP led to unexpected and intriguing results. Quenching was observed in the initial phase of titration, but addition of higher doses of MOP led to a stepwise increase in fluorescence emission coupled with a blue shift, which can be explained at least in part by formation of MOP micelles to house stray NPN molecules.

  15. Vector competence in West African Aedes aegypti Is Flavivirus species and genotype dependent.

    Directory of Open Access Journals (Sweden)

    Laura B Dickson

    2014-10-01

    Full Text Available Vector competence of Aedes aegypti mosquitoes is a quantitative genetic trait that varies among geographic locations and among different flavivirus species and genotypes within species. The subspecies Ae. aegypti formosus, found mostly in sub-Saharan Africa, is considered to be refractory to both dengue (DENV and yellow fever viruses (YFV compared to the more globally distributed Ae. aegypti aegypti. Within Senegal, vector competence varies with collection site and DENV-2 viral isolate, but knowledge about the interaction of West African Ae. aegypti with different flaviviruses is lacking. The current study utilizes low passage isolates of dengue-2 (DENV-2-75505 sylvatic genotype and yellow fever (YFV BA-55 -West African Genotype I, or YFV DAK 1279-West African Genotype II from West Africa and field derived Ae. aegypti collected throughout Senegal to determine whether vector competence is flavivirus or virus genotype dependent.Eight collections of 20-30 mosquitoes from different sites were fed a bloodmeal containing either DENV-2 or either isolate of YFV. Midgut and disseminated infection phenotypes were determined 14 days post infection. Collections varied significantly in the rate and intensity of midgut and disseminated infection among the three viruses.Overall, vector competence was dependent upon both viral and vector strains. Importantly, contrary to previous studies, sylvatic collections of Ae. aegypti showed high levels of disseminated infection for local isolates of both DENV-2 and YFV.

  16. Detection of Aedes aegypti, Aedes albopictus, and Aedes koreicus in the Area of Sochi, Russia.

    Science.gov (United States)

    Ganushkina, Ludmila A; Patraman, Ivan V; Rezza, Giovanni; Migliorini, Luigi; Litvinov, Serguei K; Sergiev, Vladimir P

    2016-01-01

    Following the identification of Aedes (Ae.) aegypti in the Sochi area in Russia at the beginning of 2000, entomological surveys were conducted during the summers of 2007, 2011, and 2012, leading to the identification of Ae. albopictus and Ae. koreicus. These findings highlight Russia as being the only country in the World Health Organization European Region with a documented presence of both Ae. aegypti and Ae. albopictus mosquitoes. Both mosquito species are found on the coasts of the Black Sea. Control measures are needed to reduce the possible risks of importing exotic vector-borne infections, such as dengue and chikungunya.

  17. History of domestication and spread of Aedes aegypti--a review.

    Science.gov (United States)

    Powell, Jeffrey R; Tabachnick, Walter J

    2013-01-01

    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.

  18. History of domestication and spread of Aedes aegypti--a review.

    Science.gov (United States)

    Powell, Jeffrey R; Tabachnick, Walter J

    2013-01-01

    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. PMID:24473798

  19. Shifting patterns of Aedes aegypti fine scale spatial clustering in Iquitos, Peru.

    Directory of Open Access Journals (Sweden)

    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

  20. Effect of temperature on the population dynamics of Aedes aegypti

    Science.gov (United States)

    Yusoff, Nuraini; Tokachil, Mohd Najir

    2015-10-01

    Aedes aegypti is one of the main vectors in the transmission of dengue fever. Its abundance may cause the spread of the disease to be more intense. In the study of its biological life cycle, temperature was found to increase the development rate of each stage of this species and thus, accelerate the process of the development from egg to adult. In this paper, a Lefkovitch matrix model will be used to study the stage-structured population dynamics of Aedes aegypti. In constructing the transition matrix, temperature will be taken into account. As a case study, temperature recorded at the Subang Meteorological Station for year 2006 until 2010 will be used. Population dynamics of Aedes aegypti at maximum, average and minimum temperature for each year will be simulated and compared. It is expected that the higher the temperature, the faster the mosquito will breed. The result will be compared to the number of dengue fever incidences to see their relationship.

  1. A single crossing-over event in voltage-sensitive Na+ channel genes may cause critical failure of dengue mosquito control by insecticides.

    Directory of Open Access Journals (Sweden)

    Koichi Hirata

    2014-08-01

    Full Text Available The voltage-sensitive sodium (Na+ channel (Vssc is the target site of pyrethroid insecticides. Pest insects develop resistance to this class of insecticide by acquisition of one or multiple amino acid substitution(s in this channel. In Southeast Asia, two major Vssc types confer pyrethroid resistance in the dengue mosquito vector Aedes aegypti, namely, S989P+V1016G and F1534C. We expressed several types of Vssc in Xenopus oocytes and examined the effect of amino acid substitutions in Vssc on pyrethroid susceptibilities. S989P+V1016G and F1534C haplotypes reduced the channel sensitivity to permethrin by 100- and 25-fold, respectively, while S989P+V1016G+F1534C triple mutations reduced the channel sensitivity to permethrin by 1100-fold. S989P+V1016G and F1534C haplotypes reduced the channel sensitivity to deltamethrin by 10- and 1-fold (no reduction, respectively, but S989P+V1016G+F1534C triple mutations reduced the channel sensitivity to deltamethrin by 90-fold. These results imply that pyrethroid insecticides are highly likely to lose their effectiveness against A. aegypti if such a Vssc haplotype emerges as the result of a single crossing-over event; thus, this may cause failure to control this key mosquito vector. Here, we strongly emphasize the importance of monitoring the occurrence of triple mutations in Vssc in the field population of A. aegypti.

  2. The wMel Strain of Wolbachia Reduces Transmission of Chikungunya Virus in Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Matthew T Aliota

    2016-04-01

    Full Text Available New approaches to preventing chikungunya virus (CHIKV are needed because current methods are limited to controlling mosquito populations, and they have not prevented the invasion of this virus into new locales, nor have they been sufficient to control the virus upon arrival. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against CHIKV. Although this approach holds much promise for limiting virus transmission, at present our understanding of the ability of CHIKV to infect, disseminate, and be transmitted by wMel-infected Ae. aegypti currently being used at Wolbachia release sites is limited.Using Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for CHIKV, even with extremely high viral titers in the bloodmeal. In addition, we examined the dynamics of CHIKV infection over the course of four to seven days post feeding. Wolbachia-infected mosquitoes remained non-infective over the duration of seven days, i.e., no infectious virus was detected in the saliva when exposed to bloodmeals of moderate viremia, but CHIKV-exposed, wild type mosquitoes did have viral loads in the saliva consistent with what has been reported elsewhere. Finally, the presence of wMel infection had no impact on the lifespan of mosquitoes as compared to wild type mosquitoes following CHIKV infection.These results could have an impact on vector control strategies in areas where Ae. aegypti are transmitting both DENV and CHIKV; i.e., they argue for further exploration, both in the laboratory and the field, on the feasibility of expanding this technology beyond DENV.

  3. 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.

  4. The wMel Strain of Wolbachia Reduces Transmission of Chikungunya Virus in Aedes aegypti

    Science.gov (United States)

    Aliota, Matthew T.; Walker, Emma C.; Uribe Yepes, Alexander; Dario Velez, Ivan; Christensen, Bruce M.; Osorio, Jorge E.

    2016-01-01

    Background New approaches to preventing chikungunya virus (CHIKV) are needed because current methods are limited to controlling mosquito populations, and they have not prevented the invasion of this virus into new locales, nor have they been sufficient to control the virus upon arrival. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against CHIKV. Although this approach holds much promise for limiting virus transmission, at present our understanding of the ability of CHIKV to infect, disseminate, and be transmitted by wMel-infected Ae. aegypti currently being used at Wolbachia release sites is limited. Methodology/Principal Findings Using Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for CHIKV, even with extremely high viral titers in the bloodmeal. In addition, we examined the dynamics of CHIKV infection over the course of four to seven days post feeding. Wolbachia-infected mosquitoes remained non-infective over the duration of seven days, i.e., no infectious virus was detected in the saliva when exposed to bloodmeals of moderate viremia, but CHIKV-exposed, wild type mosquitoes did have viral loads in the saliva consistent with what has been reported elsewhere. Finally, the presence of wMel infection had no impact on the lifespan of mosquitoes as compared to wild type mosquitoes following CHIKV infection. Conclusions/Significance These results could have an impact on vector control strategies in areas where Ae. aegypti are transmitting both DENV and CHIKV; i.e., they argue for further exploration, both in the laboratory and the field, on the feasibility of expanding this

  5. Differential Susceptibilities of Aedes aegypti and Aedes albopictus from the Americas to Zika Virus.

    Directory of Open Access Journals (Sweden)

    Thais Chouin-Carneiro

    2016-03-01

    Full Text Available Since the major outbreak in 2007 in the Yap Island, Zika virus (ZIKV causing dengue-like syndromes has affected multiple islands of the South Pacific region. In May 2015, the virus was detected in Brazil and then spread through South and Central America. In December 2015, ZIKV was detected in French Guiana and Martinique. The aim of the study was to evaluate the vector competence of the mosquito spp. Aedes aegypti and Aedes albopictus from the Caribbean (Martinique, Guadeloupe, North America (southern United States, South America (Brazil, French Guiana for the currently circulating Asian genotype of ZIKV isolated from a patient in April 2014 in New Caledonia.Mosquitoes were orally exposed to an Asian genotype of ZIKV (NC-2014-5132. Upon exposure, engorged mosquitoes were maintained at 28° ± 1 °C, a 16h:8h light:dark cycle and 80% humidity. 25-30 mosquitoes were processed at 4, 7 and 14 days post-infection (dpi. Mosquito bodies (thorax and abdomen, heads and saliva were analyzed to measure infection, dissemination and transmission, respectively. High infection but lower disseminated infection and transmission rates were observed for both Ae. aegypti and Ae. albopictus. Ae. aegypti populations from Guadeloupe and French Guiana exhibited a higher dissemination of ZIKV than the other Ae. aegypti populations examined. Transmission of ZIKV was observed in both mosquito species at 14 dpi but at a low level.This study suggests that although susceptible to infection, Ae. aegypti and Ae. albopictus were unexpectedly low competent vectors for ZIKV. This may suggest that other factors such as the large naïve population for ZIKV and the high densities of human-biting mosquitoes contribute to the rapid spread of ZIKV during the current outbreak.

  6. Historical applications of induced sterilisation in field populations of mosquitoes

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2009-11-01

    Full Text Available Abstract Research on sterile mosquito technology from 1955 to the 1980s provided a substantial body of knowledge on propagation and release of sterile mosquitoes. Radiation sterilisation and chemosterilisation have been used effectively to induce dominant lethality and thereby sterilise important mosquito vectors in the laboratory. Experimental releases of chemosterilised males provided complete control of Anopheles albimanus in a small breeding population (14-15 sq km in El Salvador. Releases of radiation sterilised males failed to control either Aedes aegypti or Anopheles quadrimaculatus in the USA. Releases of radiation-sterilised and chemosterilised male Culex quinquefasciatus in the USA and India were successful in some instances. Development of genetic sexing systems for Anopheles and improved physical separation methods for Culex have made it possible to rear and release males almost exclusively (> 99% minimizing the release of potential vectors, the females. Factors that affected efficacy in some field programmes included reduction of competitiveness by radiation, immigration of fertilized females from outside the release zones, and inability of laboratory-bred males to perform in the wild. Despite significant progress, institutional commitments to carry the process further were generally lacking in the late 1970s and until recently. Now, with renewed interest and support for further assessment of this technology, this paper summarizes the current knowledge base, prioritizes some areas of investigation, and challenges scientists and administrators to maintain an awareness of progress, remain realistic about the interpretation of new findings, and make decisions about the sterile insect technique on the basis of informed scientific documentation. Areas recommended for priority research status include the establishment of genetic sexing mechanisms that can be transferred to other mosquito species, re-examination of radiation sterilisation

  7. Genome sequence of Aedes aegypti, a major arbovirus vector.

    Science.gov (United States)

    Nene, Vishvanath; Wortman, Jennifer R; Lawson, Daniel; Haas, Brian; Kodira, Chinnappa; Tu, Zhijian Jake; Loftus, Brendan; Xi, Zhiyong; Megy, Karyn; Grabherr, Manfred; Ren, Quinghu; Zdobnov, Evgeny M; Lobo, Neil F; Campbell, Kathryn S; Brown, Susan E; Bonaldo, Maria F; Zhu, Jingsong; Sinkins, Steven P; Hogenkamp, David G; Amedeo, Paolo; Arensburger, Peter; Atkinson, Peter W; Bidwell, Shelby; Biedler, Jim; Birney, Ewan; Bruggner, Robert V; Costas, Javier; Coy, Monique R; Crabtree, Jonathan; Crawford, Matt; Debruyn, Becky; Decaprio, David; Eiglmeier, Karin; Eisenstadt, Eric; El-Dorry, Hamza; Gelbart, William M; Gomes, Suely L; Hammond, Martin; Hannick, Linda I; Hogan, James R; Holmes, Michael H; Jaffe, David; Johnston, J Spencer; Kennedy, Ryan C; Koo, Hean; Kravitz, Saul; Kriventseva, Evgenia V; Kulp, David; Labutti, Kurt; Lee, Eduardo; Li, Song; Lovin, Diane D; Mao, Chunhong; Mauceli, Evan; Menck, Carlos F M; Miller, Jason R; Montgomery, Philip; Mori, Akio; Nascimento, Ana L; Naveira, Horacio F; Nusbaum, Chad; O'leary, Sinéad; Orvis, Joshua; Pertea, Mihaela; Quesneville, Hadi; Reidenbach, Kyanne R; Rogers, Yu-Hui; Roth, Charles W; Schneider, Jennifer R; Schatz, Michael; Shumway, Martin; Stanke, Mario; Stinson, Eric O; Tubio, Jose M C; Vanzee, Janice P; Verjovski-Almeida, Sergio; Werner, Doreen; White, Owen; Wyder, Stefan; Zeng, Qiandong; Zhao, Qi; Zhao, Yongmei; Hill, Catherine A; Raikhel, Alexander S; Soares, Marcelo B; Knudson, Dennis L; Lee, Norman H; Galagan, James; Salzberg, Steven L; Paulsen, Ian T; Dimopoulos, George; Collins, Frank H; Birren, Bruce; Fraser-Liggett, Claire M; Severson, David W

    2007-06-22

    We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species. PMID:17510324

  8. 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.

  9. Genetics and morphology of Aedes aegypti (Diptera: Culicidae) in septic tanks in Puerto Rico.

    Science.gov (United States)

    Somers, Gerard; Brown, Julia E; Barrera, Roberto; Powell, Jeffrey R

    2011-11-01

    Dengue viruses, primarily transmitted by the mosquito Aedes aegypti (L.), affect an estimated 50-100 million people yearly. Traditional approaches to control mosquito population numbers, such as the use of pesticides, have had only limited success. Atypical mosquito behavior may be one reason why current vector control efforts have been less efficacious than expected. In Puerto Rico, for example, adult Ae. aegypti have been observed emerging from septic tanks. Interestingly, adults emerging from septic tanks are larger on average than adults collected from surface containers. To determine whether adults colonizing septic tanks constitute a separate Ae. aegypti population, we used 12 previously validated microsatellite loci to examine adult mosquitoes collected from both septic tanks and surface containers, but found no evidence to suggest genetic differentiation. Size differences between septic tank and surface mosquitoes were reduced when nutrient levels were held constant across experimental groups. Despite the absence of evidence suggesting a genetic difference between experimental groups in this study, Ae. aegypti emerging from septic tanks may still represent a more dangerous phenotype and should be given special consideration when developing vector control programs and designing public health interventions in the future.

  10. Aromatic plant-derived essential oil: an alternative larvicide for mosquito control.

    Science.gov (United States)

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

    2007-04-01

    Five aromatic plants, Carum carvi (caraway), Apium graveolens (celery), Foeniculum vulgare (fennel), Zanthoxylum limonella (mullilam) and Curcuma zedoaria (zedoary) were selected for investigating larvicidal potential against mosquito vectors. Two laboratory-reared mosquito species, Anopheles dirus, the major malaria vector in Thailand, and Aedes aegypti, the main vector of dengue and dengue hemorrhagic fever in urban areas, were used. All of the volatile oils exerted significant larvicidal activity against the two mosquito species after 24-h exposure. Essential oil from mullilam was the most effective against the larvae of A. aegypti, while A. dirus larvae showed the highest susceptibility to zedoary oil.

  11. Late-acting dominant lethal genetic systems and mosquito control

    Directory of Open Access Journals (Sweden)

    Scaife Sarah

    2007-03-01

    Full Text Available Abstract Background Reduction or elimination of vector populations will tend to reduce or eliminate transmission of vector-borne diseases. One potential method for environmentally-friendly, species-specific population control is the Sterile Insect Technique (SIT. SIT has not been widely used against insect disease vectors such as mosquitoes, in part because of various practical difficulties in rearing, sterilization and distribution. Additionally, vector populations with strong density-dependent effects will tend to be resistant to SIT-based control as the population-reducing effect of induced sterility will tend to be offset by reduced density-dependent mortality. Results We investigated by mathematical modeling the effect of manipulating the stage of development at which death occurs (lethal phase in an SIT program against a density-dependence-limited insect population. We found late-acting lethality to be considerably more effective than early-acting lethality. No such strains of a vector insect have been described, so as a proof-of-principle we constructed a strain of the principal vector of the dengue and yellow fever viruses, Aedes (Stegomyia aegypti, with the necessary properties of dominant, repressible, highly penetrant, late-acting lethality. Conclusion Conventional SIT induces early-acting (embryonic lethality, but genetic methods potentially allow the lethal phase to be tailored to the program. For insects with strong density-dependence, we show that lethality after the density-dependent phase would be a considerable improvement over conventional methods. For density-dependent parameters estimated from field data for Aedes aegypti, the critical release ratio for population elimination is modeled to be 27% to 540% greater for early-acting rather than late-acting lethality. Our success in developing a mosquito strain with the key features that the modeling indicated were desirable demonstrates the feasibility of this approach for

  12. Similarity solutions for systems arising from an Aedes aegypti model

    Science.gov (United States)

    Freire, Igor Leite; Torrisi, Mariano

    2014-04-01

    In a recent paper a new model for the Aedes aegypti mosquito dispersal dynamics was proposed and its Lie point symmetries were investigated. According to the carried group classification, the maximal symmetry Lie algebra of the nonlinear cases is reached whenever the advection term vanishes. In this work we analyze the family of systems obtained when the wind effects on the proposed model are neglected. Wide new classes of solutions to the systems under consideration are obtained.

  13. Repellence of essential oils of aromatic plants growing in Argentina against Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Gleiser, Raquel M; Bonino, Maria A; Zygadlo, Julio A

    2011-01-01

    Mosquitoes are vectors of pathogens to humans and domestic animals and may also have economical impacts. One approach to prevent mosquito-borne diseases is bite deterrence through the application of repellents. Currently, there is an interest to search for alternative bioactive products to the synthetic active ingredients most widely used in insect repellents. Repellence against Aedes aegypti of essential oils extracted from Acantholippia salsoloides, Aloysia catamarcensis, Aloysia polystachya, Lippia integrifolia, Lippia junelliana (Verbenaceae), Baccharis salicifolia, Euphatorium buniifolium, and Tagetes filifolia (Asteraceae) were assessed. Tests were conducted by alternatively exposing untreated and treated forehand to the mosquitoes and counting probing attempts. All essential oils tested were significantly repellent against A. aegypti when compared to untreated controls; L. junelliana was the most repellent and T. filifolia was the least based on the response of the mosquitoes to different concentrations of the essential oils (EO). Repellence may be attributed to the respective main components of each EO. PMID:20838809

  14. Global stability of a delayed mosquito-transmitted disease model with stage structure

    OpenAIRE

    B. G. Sampath Aruna Pradeep; Wanbiao Ma

    2015-01-01

    This article presents a new eco-epidemiological deterministic delay differential equation model considering a biological controlling approach on mosquitoes, for endemic dengue disease with variable host (human) and variable vector (Aedes aegypti) populations, and stage structure for mosquitoes. In this model, predator-prey interaction is considered by using larvae as prey and mosquito-fish as predator. We give a complete classification of equilibria of the model, ...

  15. Potency of Pandanus amaryllifolius and Notophanax scutellarium as Aedes albopictus Mosquito Repellent

    OpenAIRE

    Rina Marina; Endang Puji Astuti

    2012-01-01

    Aedes aegypti and Ae. albopictus mosquitoes being the vector of Dengue Haemorrhagic Fever (DHF). Various effort have been done to control the mosquitoes, including using plant extract as repellent. Pandanus amaryllifolius and Notophanax scutellarium leaf were known to posses repellent activity for mosquito species. The study aimed to examine efJectiveness of P. amaryllifolius and N. scutellarium leaves as repellent for Ae. albopictus. The result study on 1 hr treatment showed that power prote...

  16. Undesirable consequences of insecticide resistance following Aedes aegypti control activities due to a dengue outbreak.

    Directory of Open Access Journals (Sweden)

    Rafael Maciel-de-Freitas

    Full Text Available During a dengue outbreak with co-circulation of DENV-1 and -2 in the city of Boa Vista, one patient was diagnosed with DENV-4, a serotype supposed absent from Brazil for almost 30 years. The re-emergence of DENV-4 triggered the intensification of mechanical and chemical Aedes aegypti control activities in order to reduce vector density and avoid DENV-4 dissemination throughout the country.Vector control activities consisted of (a source reduction, (b application of diflubenzuron against larvae and (c vehicle-mounted space spraying of 2% deltamethrin to eliminate adults. Control activity efficacy was monitored by comparing the infestation levels and the number of eggs collected in ovitraps before and after interventions, performed in 22 Boa Vista districts, covering an area of ∼ 80% of the city and encompassing 56,837 dwellings. A total of 94,325 containers were eliminated or treated with diflubenzuron. The most frequently positive containers were small miscellaneous receptacles, which corresponded to 59% of all positive breeding sites. Insecticide resistance to deltamethrin was assessed before, during and after interventions by dose-response bioassays adopting WHO-based protocols. The intense use of the pyrethroid increased fourfold the resistance ratio of the local Ae. aegypti population only six months after the beginning of vector control. Curiously, this trend was also observed in the districts in which no deltamethrin was applied by the public health services. On the other hand, changes in the resistance ratio to the organophosphate temephos seemed less influenced by insecticide in Boa Vista.Despite the intense effort, mosquito infestation levels were only slightly reduced. Besides, the median number of eggs in ovitraps remained unaltered after control activity intensification. The great and rapid increase in pyrethroid resistance levels of natural Ae. aegypti populations is discussed in the context of both public and domestic

  17. The wMel strain of Wolbachia Reduces Transmission of Zika virus by Aedes aegypti

    OpenAIRE

    Aliota, Matthew T; Peinado, Stephen A.; Ivan Dario Velez; Jorge E Osorio

    2016-01-01

    Zika virus (ZIKV) is causing an explosive outbreak of febrile disease in the Americas. There are no effective antiviral therapies or licensed vaccines for this virus, and mosquito control strategies have not been adequate to contain the virus. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however...

  18. Kemampuan Ekstrak Daun Zodia (Evodia suaveolens) Sebagai Repellent Nyamuk Aedes aegypti Berdasarkan Lama Penggunaannya

    OpenAIRE

    Sianipar, Melati Agnes Anggreini

    2011-01-01

    Dengue Hemorrhagic Fever (DHF) disease is a contagious disease that caused by dengue virus and infected by Ae. aegypti. Since reported in 1968, this disease has become endemic and reported every year in Indonesia. One of the way to avoid it by using anti mosquitoes lotion which generally made by synthetic chemistry. Therefore, it necessary to find natural substance to avoid mosquitoes, one of the natural substances that can use is from zodia leaves (Evodia suaveolens) as repellent. The a...

  19. Identification of carboxylesterase genes implicated in temephos resistance in the dengue vector Aedes aegypti.

    OpenAIRE

    Rodolphe Poupardin; Wannaporn Srisukontarat; Cristina Yunta; Hilary Ranson

    2014-01-01

    BACKGROUND: Thailand is currently experiencing one of its worst dengue outbreaks in decades. As in most countries where this disease is endemic, dengue control in Thailand is largely reliant on the use of insecticides targeting both immature and adult stages of the Aedes mosquito, with the organophosphate insecticide, temephos, being the insecticide of choice for attacking the mosquito larvae. Resistance to temephos was first detected in Aedes aegypti larvae in Thailand approximately 25 years...

  20. 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.

  1. PEMETAAN, KARAKTERISTIK HABITAT DAN STATUS RESISTENSI Aedes aegypti DI KOTA BANJARMASIN KALIMANTAN SELATAN

    Directory of Open Access Journals (Sweden)

    Safitri -

    2013-12-01

    Full Text Available ABSTRACT. Control program of Aedes aegypti in Banjarmasin by using Malation has been done since almost 15 years ago. Related to this, a study about distribution and resistence of Ae.aegypti inBanjarmasin has been done. Ae.aegypti shown to be in almost all area in Banjarmasin, with water container in the bathroom and in the house are more liked. Susceptibility test showed thatthis mosquito was resistence to Malation 0,8%. Therefor, a policy to change this type of insecticide is needed.Key words : Ae.aegypti, resistence, dengue fever, Malation ABSTRAKProgram pengendalian nyamuk Aedes aegypti di Banjarmasin dengan menggunakan Malation telah dilakukan sejak hampir 15 tahun lalu. Terkait hal ini, sebuah studi tentang distribusi dan resistensi Ae. aegypti di Banjarmasin telah dilakukan. Ae. aegypti ditemukan di hampir semua wilayah di Banjarmasin dan lebih menyukai bak mandi dan penampungan air lainnya di dalam rumah. Uji Kerentanan menunjukkan bahwa nyamukini resisten terhadap Malation 0,8%. Maka, kebijakan untuk mengubah jenis insektisida yang digunakan sangat dibutuhkan Kata kunci: Ae. aegypti, resistensi, demam berdarah, Malation

  2. The endosymbiotic bacterium Wolbachia induces resistance to dengue virus in Aedes aegypti.

    Science.gov (United States)

    Bian, Guowu; Xu, Yao; Lu, Peng; Xie, Yan; Xi, Zhiyong

    2010-04-01

    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. PMID:20368968

  3. 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.

  4. The effects of plant essential oils on escape response and mortality rate of Aedes aegypti and Anopheles minimus.

    Science.gov (United States)

    Sathantriphop, Sunaiyana; Achee, Nicole L; Sanguanpong, Unchalee; Chareonviriyaphap, Theeraphap

    2015-12-01

    The High Throughput Screening System (HITSS) has been applied in insecticide behavioral response studies with various mosquito species. In general, chemical or natural compounds can produce a range of insect responses: contact irritancy, spatial repellency, knock-down, and toxicity. This study characterized these actions in essential oils derived from citronella, hairy basil, catnip, and vetiver in comparison to DEET and picaridin against Aedes aegypti and Anopheles minimus mosquito populations. Results indicated the two mosquito species exhibited significantly different (P0.05) against Ae. aegypti. Spatial repellency responses were elicited in both mosquito species when exposed to all compounds, but the strength of the repellent response was dependent on compound and concentration. Data show that higher test concentrations had greatest toxic effects on both mosquito populations, but vetiver had no toxic effect on Ae. aegypti and picaridin did not elicit toxicity in either Ae. aegypti or An. minimus at any test concentration. Ultimately, this study demonstrates the ability of the HITSS assay to guide selection of effective plant essential oils for repelling, irritating, and killing mosquitoes. PMID:26611967

  5. The effects of plant essential oils on escape response and mortality rate of Aedes aegypti and Anopheles minimus.

    Science.gov (United States)

    Sathantriphop, Sunaiyana; Achee, Nicole L; Sanguanpong, Unchalee; Chareonviriyaphap, Theeraphap

    2015-12-01

    The High Throughput Screening System (HITSS) has been applied in insecticide behavioral response studies with various mosquito species. In general, chemical or natural compounds can produce a range of insect responses: contact irritancy, spatial repellency, knock-down, and toxicity. This study characterized these actions in essential oils derived from citronella, hairy basil, catnip, and vetiver in comparison to DEET and picaridin against Aedes aegypti and Anopheles minimus mosquito populations. Results indicated the two mosquito species exhibited significantly different (P0.05) against Ae. aegypti. Spatial repellency responses were elicited in both mosquito species when exposed to all compounds, but the strength of the repellent response was dependent on compound and concentration. Data show that higher test concentrations had greatest toxic effects on both mosquito populations, but vetiver had no toxic effect on Ae. aegypti and picaridin did not elicit toxicity in either Ae. aegypti or An. minimus at any test concentration. Ultimately, this study demonstrates the ability of the HITSS assay to guide selection of effective plant essential oils for repelling, irritating, and killing mosquitoes.

  6. Larvicide and oviposition deterrent effects of fruit and leaf extracts from Melia azedarach L. on Aedes aegypti (L.) (Diptera: Culicidae).

    Science.gov (United States)

    Coria, C; Almiron, W; Valladares, G; Carpinella, C; Ludueña, F; Defago, M; Palacios, S

    2008-05-01

    Aedes aegypti (L.) (Diptera: Culicidae), the main urban vector of dengue, has developed resistance to various insecticides, making its control increasingly difficult. We explored the effects of Argentine Melia azedarach L. (Meliaceae) fruit and senescent leaf extracts on Ae. aegypti larval development and survival, by rearing cohorts of first instar mosquitoes in water with different extract concentrations. We also analysed oviposition deterrent activity in choice tests with extract-treated ovitraps. The leaf extract showed a strong larvicide activity, with all larvae dying before pupation, and significantly delayed development time. It strongly inhibited oviposition by Ae. aegypti females. The fruit extract showed much weaker effects. This first report of highly effective larvicidal, growth regulating and oviposition deterrent activity of a senescent leaf extract of M. azedarach against Ae. aegypti, suggests that such extract could represent a promising tool in the management of this mosquito pest.

  7. 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...

  8. Expression Profile of Genes during Resistance Reversal in a Temephos Selected Strain of the Dengue Vector, Aedes aegypti

    OpenAIRE

    Clare Strode; Maria de Melo-Santos; Tereza Magalhães; Ana Araújo; Contancia Ayres

    2012-01-01

    BACKGROUND: The mosquito Aedes aegypti is one of the most important disease vectors because it transmits two major arboviruses, dengue and yellow fever, which cause significant global morbidity and mortality. Chemical insecticides form the cornerstone of vector control. The organophosphate temephos a larvicide recommended by WHO for controlling Ae. aegypti, however, resistance to this compound has been reported in many countries, including Brazil. METHODOLOGY/PRINCIPAL FINDINGS: The aim of th...

  9. The efficacy of a chitin synthesis inhibitor against field populations of organophosphate-resistant Aedes aegypti in Brazil

    OpenAIRE

    Nathalia Giglio Fontoura; Diogo Fernandes Bellinato; Denise Valle; José Bento Pereira Lima

    2012-01-01

    The mosquito Aedes aegypti is the main focus of dengue control campaigns. Because of widespread resistance against conventional chemical insecticides, chitin synthesis inhibitors (CSIs) are considered control alternatives. We evaluated the resistance status of four Brazilian Ae. aegypti populations to both the organophosphate temephos and the pyrethroid deltamethrin, which are used in Brazil to control larvae and adults, respectively. All vector populations exhibited high levels of temephos r...

  10. Molecular characterization of Aedes aegypti (L.) (Diptera: Culicidae) of Easter Island based on analysis of the mitochondrial ND4 gene

    OpenAIRE

    Claudia Andrea Núñez; Christian Raúl González; Víctor Obreque; Brenda Riquelme; Carolina Reyes; Mabel Rojas

    2016-01-01

    ABSTRACT Aedes aegypti mosquitoes are the main vector of viruses Dengue, Zika and Chikungunya. Shortly after the first report of the dengue vector Ae. aegypti in Easter Island (Rapa Nui) in late 2000, the first disease outbreak dengue occurred. Viral serotyping during the 2002 outbreak revealed a close relationship with Pacific DENV-1 genotype IV viruses, supporting the idea that the virus most likely originated in Tahiti. Mitochondrial NADH dehydrogenase subunit 4 (ND4) DNA sequences generat...

  11. Permethrin-treated clothing as protection against the Dengue vector, Aedes aegypti : extent and duration of protection.

    OpenAIRE

    Sarah DeRaedt Banks; James Orsborne; Salvador A. Gezan; Harparkash Kaur; Annelies Wilder-Smith; Lindsey, Steve W.; Logan, James G

    2015-01-01

    INTRODUCTION: 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. METHODS: 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...

  12. 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.

  13. 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.

  14. Transgenic expression of the Aedes aegypti CYP9J28 confers pyrethroid resistance in Drosophila melanogaster

    NARCIS (Netherlands)

    N. Pavlidi; M. Monastirioti; P. Daborn; T. Van Leeuwen; J. Vontas

    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,

  15. The effect of chitin synthesis inhibitors on the development of Brugia malayi in Aedes aegypti.

    Science.gov (United States)

    Mohapatra, R; Ranjit, M R; Dash, A P

    1996-09-01

    Two chitin synthesis inhibitors (CSIs) viz., triflumuron and hexaflumuron interfere++ with the development of Brugia malayi in Aedes aegypti (a black-eyed Liverpool strain). The development of B. malayi was slow in both the treated populations and the infection rate, infectivity rate and L3 load per mosquito decreased significantly (P triflumuron. PMID:8984113

  16. Role of Aedes aegypti and Aedes albopictus during the 2011 dengue fever epidemics in Hanoi, Vietnam

    Institute of Scientific and Technical Information of China (English)

    Pham; Thi; Kim; Lien; Vu; Trong; Duoc; Laurent; Gavotte; Emmanuel; Cornillot; Phan; Thi; Nga; Laurence; Briant; Roger; Frutos; Tran; Nhu; Duong

    2015-01-01

    Objective: To record the human cases of dengue fever(DF) and investigate the Aedes mosquito species circulating during the Hanoi 2011 DF epidemics. Methods: 24 different outbreak points were recorded in 8 districts between August and December 2011. Results: 140 patients were hospitalized following dengue diagnostic with a predominance of males(59.3%) and the 15-34 age class. Only DENV-1(11.27%) and DENV-2(88.73%) serotypes were detected in human samples. Mosquito sampling performed in and around patients households revealed the predominance of Aedes aegypti(95.15%) versus Aedes albopictus(4.85%). There is a positive correlation between the population density of Aedes aegypti and the number of human cases and duration of outbreaks. Conclusions: This was not observed for Aedes albopictus. 3 pools of Aedes aegypti were positive with dengue virus, two with DENV-1 and one with DENV-2.

  17. Atmospheric control of Aedes aegypti populations in Buenos Aires (Argentina) and its variability

    Science.gov (United States)

    de Garín, A.; Bejarán, R. A.; Carbajo, A. E.; de Casas, S. C.; Schweigmann, N. J.

    The mosquito Aedes aegypti is the main urban vector responsible for the transmission of dengue fever and dengue hemorrhagic fever. The city of Buenos Aires, Argentina, is located at the southern end of the world distribution of the species. The population abundance of Ae. aegypti is mainly regulated by environmental factors. We calculated the potential number of times that a female could lay eggs during its mean life expectancy, based on potential egg production and daily meteorological records. The model considers those variables implying physical hazard to the survival of Ae. aegypti, mosquito flying activity and oviposition. The results, obtained after calibration and validation of the model with field observations, show significant correlation (Pclimatic change) can be observed. The climatic variability in the last decade resembles conditions at the end of 19th century.

  18. Atmospheric control of Aedes aegypti populations in Buenos Aires (Argentina) and its variability

    Science.gov (United States)

    de Garín, A.; Bejarán, R. A.; Carbajo, A. E.; de Casas, S. C.; Schweigmann, N. J.

    The mosquito Aedes aegypti is the main urban vector responsible for the transmission of dengue fever and dengue hemorrhagic fever. The city of Buenos Aires, Argentina, is located at the southern end of the world distribution of the species. The population abundance of Ae. aegypti is mainly regulated by environmental factors. We calculated the potential number of times that a female could lay eggs during its mean life expectancy, based on potential egg production and daily meteorological records. The model considers those variables implying physical hazard to the survival of Ae. aegypti, mosquito flying activity and oviposition. The results, obtained after calibration and validation of the model with field observations, show significant correlation (Paegypti reproduction (linked to the urban climatic change) can be observed. The climatic variability in the last decade resembles conditions at the end of 19th century.

  19. Mosquito larvicidal and silver nanoparticles synthesis potential of plant latex

    Directory of Open Access Journals (Sweden)

    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.

  20. Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

    Objective: To determine the ovicidal and repellent activities of methanol leaf extract ofErvatamia coronaria (E. coronaria) and Caesalpinia pulcherrima (C. pulcherrima) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi). Methods: 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/cm2 under the laboratory conditions.Results: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/cm2 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. Conclusions: 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.

  1. Embryonic desiccation resistance in Aedes aegypti: presumptive role of the chitinized Serosal Cuticle

    Directory of Open Access Journals (Sweden)

    Peixoto Alexandre

    2008-09-01

    Full Text Available Abstract Background One of the major problems concerning dengue transmission is that embryos of its main vector, the mosquito Aedes aegypti, resist desiccation, surviving several months under dry conditions. The serosal cuticle (SC contributes to mosquito egg desiccation resistance, but the kinetics of SC secretion during embryogenesis is unknown. It has been argued that mosquito SC contains chitin as one of its components, however conclusive evidence is still missing. Results We observed an abrupt acquisition of desiccation resistance during Ae. aegypti embryogenesis associated with serosal cuticle secretion, occurring at complete germ band extension, between 11 and 13 hours after egglaying. After SC formation embryos are viable on dry for at least several days. The presence of chitin as one of the SC constituents was confirmed through Calcofluor and WGA labeling and chitin quantitation. The Ae. aegypti Chitin Synthase A gene (AaCHS1 possesses two alternatively spliced variants, AaCHS1a and AaCHS1b, differentially expressed during Ae. aegypti embryonic development. It was verified that at the moment of serosal cuticle formation, AaCHS1a is the sole variant specifically expressed. Conclusion In addition to the peritrophic matrix and exoskeleton, these findings confirm chitin is also present in the mosquito serosal cuticle. They also point to the role of the chitinized SC in the desiccation resistance of Ae. aegypti eggs. AaCHS1a expression would be responsible for SC chitin synthesis. With this embryological approach we expect to shed new light regarding this important physiological process related to the Ae. aegypti life cycle.

  2. PENGARUH FREKUENSI PENGHISAPAN DARAH TERHADAP PERKEMBANGAN, REPRODUKSI,VERTILITAS DAN RASIO SEX Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Riyani Setiyaningsih

    2014-06-01

    Full Text Available Aedes aegypti is a vector of Dengue hemorrhagic fever in Indonesia. Aedesaegypti has a high reproduction ability. Each individual can produce 50-100 eggs. Which80% of them are fertile. The mosquito is multiple biting (which means each individualsucks blood several time. Based on that background, this research was aimed torecognize the frequency of blood sucking to development, reproduction, fertility, and sexratio of Ae. aegypti. Thirty Ae. aegypti mosquito were put into the plastic cupsindividually, then fed with mammals. The treatments were the first, second, third, fourth,and fifth blood sucking. The eggs produced in each blood sucking were hatched andmaintain to become mosquitoes. The parameter measured from each blood sucking istotal egg production, egg fertility, larvae mortality, pupae mortality, and sex ratio. Theresult of the research shows that the frequency of blood sucking affects the production ofegg fertility, but does not affect the total egg production, larvae mortality, pupaemortality, and sex ratio significantly.Key words: sex ratio, egg fertility, reproduction Aedes aegypti adalah vektor Demam berdarah dengue di Indonesia. Ae aegyptimempunyai kemampuan berkembang biak dengan cepat. Setiap individu mempunyaikemampuan menghasilkan telur 50 sampai 100 ekor skali bertclur. Ae. aegypti bersifat multibiting, masing-masing individu mempunyai kemampuan menghisap darah beberapa kali dalamkurun waktu tertentu. Berdasarkan latar belakang tersebut tujuan penelitian ini adalahmendapatkan pengaruh frekuensi penghisapan darah terhadap perkembangan reproduksi,fcrtilitas, dan rasio sex dari Ae. aegypti. Ae aegypti dimasukkan ke dalam cup plastik secaraindividual, kemudian diberikan darah mamalia selama kurang lebih 3 menit. Pemberian darahdilakukan secara bertahap yaitu pemberian darah pertama, kedua, ketiga, ke empat, dan ke limaTelur-telur yang dihasilkan pada masing-masing penghisapan darah di tetaskan dan dipeliharasampai menjadi nyamuk

  3. Reduction of malaria transmission to Anopheles mosquitoes with a six-dose regimen of co-artemether.

    Directory of Open Access Journals (Sweden)

    Colin J Sutherland

    2005-04-01

    Full Text Available BACKGROUND: Resistance of malaria parasites to chloroquine (CQ and sulphadoxine-pyrimethamine (SP is increasing in prevalence in Africa. Combination therapy can both improve treatment and provide important public health benefits if it curbs the spread of parasites harbouring resistance genes. Thus, drug combinations must be identified which minimise gametocyte emergence in treated cases, and so prevent selective transmission of parasites resistant to any of the partner drugs. METHODS AND FINDINGS: In a randomised controlled trial, 497 children with uncomplicated falciparum malaria were treated with CQ and SP (three doses and one dose respectively; n = 91, or six doses of artemether in fixed combination with lumefantrine (co-artemether [Coartem, Riamet] (n = 406. Carriage rates of Plasmodium falciparum gametocytes and trophozoites were measured 7, 14, and 28 d after treatment. The infectiousness of venous blood from 29 children carrying P. falciparum gametocytes 7 d after treatment was tested by membrane-feeding of Anopheles mosquitoes. Children treated with co-artemether were significantly less likely to carry gametocytes within the 4 weeks following treatment than those receiving CQ/SP (30 of 378 [7.94%] versus 42 of 86 [48.8%]; p < 0.0001. Carriers in the co-artemether group harboured gametocytes at significantly lower densities, for shorter periods (0.3 d versus 4.2 d; p < 0.0001 and were less infectious to mosquitoes at day 7 (p < 0.001 than carriers who had received CQ/SP. CONCLUSIONS: Co-artemether is highly effective at preventing post-treatment transmission of P. falciparum. Our results suggest that co-artemether has specific activity against immature sequestered gametocytes, and has the capacity to minimise transmission of drug-resistant parasites.

  4. Ecotoxicological assessment of pyriproxyfen under environmentally realistic exposure conditions of integrated vector management for Aedes aegypti control in Brazil.

    Science.gov (United States)

    Caixeta, Evelyn Siqueira; Silva, Carolina Fabiano; Santos, Vanessa Santana Vieira; Olegário de Campos Júnior, Edimar; Pereira, Boscolli Barbosa

    2016-01-01

    There is increasing concern to control Aedes aegypti mosquito exposure in developing countries such as Brazil. Thus, integrated approaches using a combination of chemical, pyriproxyfen larvicide, and biological, Xiphophorus maculatus, larvivorous fish species approaches are necessary and important to initiate more effective control against mosquito borne diseases. This study describes the toxicological effects of pyriproxyfen larvicide on the fish Xiphophorus maculatus, the larvivorous fish species employed to destroy A. aegypti larvae mosquito species. The toxicological profile of pyriproxyfen was evaluated to determine compatible concentrations for the use of this chemical in conjunction with X. maculatus as an integrated approach against A. aegypti mosquito larvae. According to the behavioral responses of fish, the no-observed-effect concentration (NOEC) and lowest-observed-effect concentration (LOEC) of pyriproxyfen were determined to be 2.5 and 5 µg/L, respectively. Bioassays indicated that although pyriproxyfen was not lethal to X. maculatus, the application of this compound at a concentration reported to control the emergence of A. aegypti larvae may decrease the swimming performance of larvivorous fish and their ability to ingest A. aegypti L4 larvae. Data show that integration of biological larvivorous fish and chemical larvicides is more effective when the appropriate larvicide concentration is utilized. PMID:27458879

  5. 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

  6. Larvicidal and repellent activity of tetradecanoic acid againstAedes aegypti (Linn.) andCulex quinquefasciatus (Say.) (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Sivakumar R; Jebanesan A; Govindarajan M; Rajasekar P

    2011-01-01

    Objective:To investigate the larvicidal and repellent efficacy of tetradecanoic acid against Aedes aegypti (Ae. aegypti) L. andCulex quinquefasciatus (Cx. quinquefasciatus) Say (Diptera: Culicidae).Methods: Larvicidal efficacy of tetradecanoic acid was tested at various concentrations against the early third instar larvae of Ae. aegypti andCx. quinquefasciatus. The repellent activity was determined against two mosquito species at three concentrations viz.,1.0,2.5 and5.0 ppm under the laboratory conditions.Results: The tetradecanoic acid was found to be more effective againstCx. quinquefasciatus thanAe. aegypti larvae. TheLC50values were14.08 ppm and25.10 ppm, respectively. Tetradecanoic acid showed lesser repellency againstAe. aegypti andCx. quinquefasciatus. The highest repellency was observed in higher concentration of5.0 mg/cm2provided100% protection up to60 and 90 min againstAe. aegypti andCx. quinquefasciatusrespectively.Conclusions: From the results it can be concluded the tetradecanoic acid is a potential for controlling Cx. quinquefasciatus andAe. aegypti mosquitoes.

  7. Aedes aegypti Global Suitability Maps Using a Water Container Energy Balance Model for Dengue Risk Applications

    Science.gov (United States)

    Steinhoff, D.

    2015-12-01

    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 eventually adults is largely dependent on the availability of water and the thermal properties of the water in the containers. Recent work has shown that physics-based approaches toward modeling container water properties are promising for resolving the complexities of container water dynamics and the effects on immature mosquito development. An energy balance container model developed by the author, 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 weather data. Here we use WHATCH'EM with NASA Earth Science products used as input to construct global suitability maps based on established water temperature ranges for immature Ae. aegypti mosquitoes. A proxy for dengue risk is provided from habitat suitability, but also population estimates, as Ae. aegypti is closely associated with human activity. NASA gridded Global Population of the World data is used to mask out rural areas with low dengue risk. Suitability maps are illustrated for a variety of containers (size, material, color) and shading scenarios.

  8. Mosquito infection responses to developing filarial worms.

    Directory of Open Access Journals (Sweden)

    Sara M Erickson

    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. Superior reproductive success on human blood without sugar is not limited to highly anthropophilic mosquito species

    OpenAIRE

    Braks, M.A.H.; JULIANO, S. A.; LOUNIBOS, L. P.

    2006-01-01

    Anthropophilic mosquitoes such as Aedes aegypti L. (Diptera: Culicidae) have been shown to have superior reproductive success on human blood when sugar is not available. Life-table experiments were conducted with Aedes albopictus Skuse and Ae. aegypti to compare the effects of sugar availability on age-specific survivorship, lifetime and daily fecundity, and blood-feeding frequency when offered human blood daily. There were no significant interactions between the effects of sugar availability...

  10. Chikungunya virus and its mosquito vectors.

    Science.gov (United States)

    Higgs, Stephen; Vanlandingham, Dana

    2015-04-01

    Chikungunya virus (CHIKV), a mosquito-borne alphavirus of increasing public health significance, has caused large epidemics in Africa and the Indian Ocean basin; now it is spreading throughout the Americas. The primary vectors of CHIKV are Aedes (Ae.) aegypti and, after the introduction of a mutation in the E1 envelope protein gene, the highly anthropophilic and geographically widespread Ae. albopictus mosquito. We review here research efforts to characterize the viral genetic basis of mosquito-vector interactions, the use of RNA interference and other strategies for the control of CHIKV in mosquitoes, and the potentiation of CHIKV infection by mosquito saliva. Over the past decade, CHIKV has emerged on a truly global scale. Since 2013, CHIKV transmission has been reported throughout the Caribbean region, in North America, and in Central and South American countries, including Brazil, Columbia, Costa Rica, El Salvador, French Guiana, Guatemala, Guyana, Nicaragua, Panama, Suriname, and Venezuela. Closing the gaps in our knowledge of driving factors behind the rapid geographic expansion of CHIKV should be considered a research priority. The abundance of multiple primate species in many of these countries, together with species of mosquito that have never been exposed to CHIKV, may provide opportunities for this highly adaptable virus to establish sylvatic cycles that to date have not been seen outside of Africa. The short-term and long-term ecological consequences of such transmission cycles, including the impact on wildlife and people living in these areas, are completely unknown.

  11. Assessing the feasibility of controlling Aedes aegypti with transgenic methods: a model-based evaluation.

    Directory of Open Access Journals (Sweden)

    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.

    Directory of Open Access Journals (Sweden)

    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. Controlling Aedes aegypti population as DHF vector with radiation based-sterile insect technique in Banjarnegara Regency, Central Java

    International Nuclear Information System (INIS)

    The control program of dengue hemorrhagic fever (DHF) in Indonesia is still a problem due to the incomplete integrated handling. Sterile insect technique (SIT) for Aedes aegypti as DHF vector was considered as a potential strategy for controlling the DHF. A preliminary survey was carried out to determine the characteristic of A aegypti population in the study site before the implementation of SIT. The implementation of radiation based-SIT was carried out in Krandegan and Kutabanjar Villages of Banjarnegara Regency, Central Java which involved 99 houses. One hundred gamma rays irradiated male mosquitoes were released to each house up to five times. The eggs, larvae and adult mosquitoes were collected using ovitrap and weekly observed. The initial population density of A. aegypti in the studied area was obtained to be 6 mosquitoes per house with the mean index of house was 15.86% and the mean sterility of sterilized mosquitoes was 79.16%. The SIT effectively reduced A. aegypti population after the fifth release of irradiated mosquitoes into the houses. It can be assumed that the SIT was effective in controlling DHF vector in the studied area, nevertheless, it will be more effective if it is combined with other handling techniques. (author)

  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. 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

  16. 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

  17. The combination of the entomopathogenic fungus Metarhizium anisopliae with the insecticide Imidacloprid increases virulence against the dengue vector Aedes aegypti (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    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. Chemical control of Aedes aegypti: a historical perspective

    Directory of Open Access Journals (Sweden)

    Alejandra Manjarres-Suarez

    2013-06-01

    Full Text Available Objective: To describe the use of chemical insecticides throughout history as the main tool to fight against Aedes aegypti, a vector of dengue virus. Methods: A text mining approach was conducted on databases, such as PUBMED and SCIENCE DIRECT, using the keywords “Aedes aegypti”, combined with the words “insecticides”, “resistance”, “organochlorines”, “organophosphates”, “carbamates” and “pyrethroids”. Results related to historical information dealing with the chemical control of Aedes aegypti, in particular those containing data on insecticide resistance for this species, were scrutinized and analyzed. Results: Different chemical groups have been utilized to control A. aegypti, including organochlorine, organophosphate, carbamate and pyrethroid insecticides. In general, the tendency has been to replace a particular pesticide, for which resistance had been detected, for a new one, mosquito-sensitive, and with little evidence of deleterious effects derived from its use. The spread of resistance has been registered in several countries of America, Asia and Africa. Two mechanisms have been highly cited to be responsible for the resistance; the increase activity of detoxifying enzymes, and structural changes in the insecticide target site, mostly within the central nervous system. Conclusion: Excessive use of chemical insecticides and the lack of dosing control have led to widespread resistance in A. aegypti, as no “safer” alternative chemical options are available for vector control in different countries, impacting human health.

  19. Sterculia guttata seeds extractives--an effective mosquito larvicide.

    Science.gov (United States)

    Katade, Sushama R; Pawar, Pushpa V; Wakharkar, Radhika D; Deshpande, Nirmala R

    2006-08-01

    The larvicidal activity of ethanol, chloroform and hexane soxhlet extracts obtained from S. guttata seeds was investigated against the IVth instar larvae of Dengue fever vector, Aedes aegypti and filarial vector, Culex quinquefasciatus. All extracts including fractions of ethanol extract exhibited 100% larval kill within 24 hr exposure period at 500 ppm concentration. Fraction A1 of ethanol was found to be most promising; its LC50 was 21.552 and 35.520 ppm against C. quinquefasciatus and A. aegypti respectively. Naturally occurring S. guttata seed derived fractions merit further study as potential mosquito larval control agents or lead compounds.

  20. The wMelPop strain of Wolbachia interferes with dopamine levels in Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Eyles Darryl W

    2011-02-01

    Full Text Available Abstract Wolbachia is an intracellular bacterium that has been stably transinfected into the mosquito vector of dengue, Aedes aegypti. This inherited infection causes a range of metabolic and phenotypic alterations in the mosquito, which might be related to neuronal abnormalities. In order to determine if these alterations were caused by the manipulation of neuroamines by this bacterium, we studied the expression of genes involved in the dopamine biosynthetic pathway and also measured the amount of dopamine in infected and uninfected mosquitoes of different ages. Wolbachia-infected mosquitoes exhibit greater expression of some genes related to the melanization pathway, but not for those directly linked to dopamine production. Although dopamine levels were higher in Wolbachia-positive mosquitoes this was not consistent across all insect ages nor was it related to the previously described Wolbachia induced "bendy" and "shaky" phenotypes.

  1. Larvicidal potential of commercially available pine (Pinus longifolia) and cinnamon ( Cinnamnomum zeylanicum) oils against dengue fever mosquito, Aedes aegypti L.( Diptera: Culicidae)%市售长叶松油和锡兰肉桂油对登革热媒蚊埃及伊蚊的灭幼效果

    Institute of Scientific and Technical Information of China (English)

    Radhika WARIKOO; Naim WAHAB; Sarita KUMAR

    2011-01-01

    The aromatic nature of pine and cinnamon oils has established them as good adult repellents but their larvicidal efficacy against mosquitoes has not been explored much.Keeping this in view,laboratory studies were conducted to uncover the larvicidal potential of commercially available pine ( Pinus longifolia) oil and cinnamon ( Cinnamomum zeylanicum) oil against the early 4th instar larvae of Aedes aegypti, originating from Delhi, India.The larvicidal effects were investigated in terms of the larval mortality, behavioural and morphological changes, if any.Our studies revealed the larvicidal efficiency of both the oils against 4th instar larvae of Ae.aegypti, the pine oil proving to be more effective than the cinnamon oil.The LC50 and LC70values exhibited by pine oil were 0.33093 mg/L and 0.54476 mg/L,respectively, while the values obtained with cinnamon oil were 0.63159 mg/L and 0.77736 mg/L,respectively.It was further observed that at LC90 the larvicidal potential of cinnamon oil surpassed that of the pine oil, exhibiting a value of 1.11879 mg/L as in comparison to 1.04915 mg/L shown by pine oil.The behavioural changes as excitation, restlessness, tremors, and convulsions followed by paralysis observed in the treated larvae suggest a probable effect of the oils on their neuromuscular system.Microscopic study of morphological alterations in the treated larvae revealed that most of their organs had a normal structural appearance as that of controls except the little internal shrinkage in anal gills leading to the structural deformity.This indicates the anal gills as the probable action sites of the oil extracts and dysfunction of the gills leading to larval mortality.The potential of oils as new types of larvicides for the control of mosquitoes are explored.%松油和桂皮油由于具有芳香性气味,因而成为良好的成虫驱避剂,但是关于它们对蚊虫的杀幼虫作用研究不多.为揭示市售的长叶松Pinus longifolia

  2. Mosquitocidal activity of Polygala arvensis Willd against Aedes aegypti (Linn., Anopheles stephensi (Liston. and Culex quinquefasciatus (Say. (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    M. Deepa

    2014-12-01

    Full Text Available To determine the larvicidal, ovicidal and repellent activities of benzene and methanol extract of Polygala arvensis against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus Twenty five 3rd instar larvae of selected mosquitoes species were exposed to various concentrations (60-300 ppm and were assayed in the laboratory by using the protocol of WHO 2005; the 24 h LC50 values of the P. Arvensis leaf extract was determined following Probit analysis. The ovicidal activity was determined against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus exposed to variousconcentrations were tested under laboratory conditions and the hatch rates were assessed 120hrs post treatment. The repellent efficacy was determined against selected mosquitoes at three concentrations viz., 1.0, 2.0 and 3.0 mg/cm2 under the laboratory conditions. The LC50 and LC90 values of benzene and methanol extract of P. arvensis against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus larvae in 24 h were 75.32, 88.26, 82.46, 58.21, 46.37, 42.68 and 260.48, 275.26, 251.39, 208.45, 189.82 and 130.44 ppm, respectively. It has been noticed that the higher concentrations of P. arvensis extractspossesses strong ovicidal activity at 200 ppm concentration against Ae. aegypti, An. stephensi and C. quinquefasciatus, no egg hatchability was recorded. In the same way, methanol extracts showed maximum ovicidal activity followed by benzene extract against selected vector mosquitoes. In repellent activity, among two extracts tested P. arvensis methanol extract had strong repellent action against selected mosquitoes as it provided 100% protection against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus for 280min. From the results it can be concluded the P. arvensis extract was an excellent potential for controlling Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes.

  3. Especificidade da armadilha Adultrap para capturar fêmeas de Aedes aegypti (Diptera: Culicidae Specificity of the Adultrap for capturing females of Aedes aegypti (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    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.

  4. Bloodmeal microfilariae density and the uptake and establishment of Wuchereria bancrofti infections in Culex quinquefasciatus and Aedes aegypti

    OpenAIRE

    Albuquerque Cleide MR; Cavalcanti Vânia MS; Melo Maria Alice V; Verçosa Paulo; Regis Lêda N; Hurd Hilary

    1999-01-01

    The relationship between ingestion of microfilariae (mf), production of infective larvae (L3) and mf density in human blood has been suggested as an important determinant in the transmission dynamics of lymphatic filariasis. Here we assess the role of these factors in determining the competence of a natural vector Culex quinquefasciatus and a non vector Aedes aegypti to transmit Wuchereria bancrofti. Mosquitoes were infected via a membrane feeding procedure. Both mosquito species ingested mor...

  5. Oviposition and Embryotoxicity of Indigofera suffruticosa on Early Development of Aedes aegypti (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    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. Genome Investigations of Vector Competence in Aedes aegypti to Inform Novel Arbovirus Disease Control Approaches

    Directory of Open Access Journals (Sweden)

    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.

  7. PENENTUAN STATUS RESISTENSI Aedes aegypti DENGAN METODE SUSCEPTIBILITY DI KOTA CIMAHI TERHADAP CYPERMETHRIN

    Directory of Open Access Journals (Sweden)

    Firda Yanuar Pradani

    2013-12-01

    Full Text Available ABSTRACT Background:  vector control of DBD usually doing by using insecticides, whether by government or insecticides used in household.  Using to much insecticides for long time can caused resistence of mosquito.  This research aim to know resistance status of Aedes aegypti from endemic rural in district Cimahi to cypermethrin (synthetic pyretroid. Methods:  resistance status knowing by susceptibility methods (WHO standard with usingimpregnated paper that containing cypermethrin 0,2% and 0,4%.  Aedes aegypti spread by it for 15, 30, 45 and 60 minutes.  Number of mortality count by percentage death mosquito in each time and each concentration of cypermethrin.  Data interpreted by WHO standard, which percentage ofdeath mosquito <80% is resistance, between 80-98% is tolerance and 99-100% is susceptible. Result: Aedes aegypti from endemic rural in district Cimahi showed resistance of cypermethrin 0,2% and 0,4%. This result showed that all mosquito still alive after 15 minutes spreading bycypermethrin 0,2%, and only 6,7% mosquito death in cypermethrin 0,4%.  After 30 minutes, death mosquito counted 46,7% in cypermethrin 0,2% and 73,3% in 0,4%.  46,7% mosquito was death in 45 and 60 minutes spreading by cypermethrin 0,2% and 73,3% in 0,4%.  The resultshowed resistance ratio (RR50 of mosquito is 4,6.Conclution: Aedes aegypti from endemic rural in distric Cimahi showed a resistance to cypermethrin 0,2% and 0,4%.Key words:  Aedes aegypti, cypermethrin, resistance, Cimahi district ABSTRAK Latar Belakang: pengendalian vektor DBD biasanya dilakukan dengan menggunakan insektisida, apakah oleh pemerintah atau insektisida yang digunakan dalam rumah tangga. penggunaan insektisida dalam jumlah yang banyak dan waktu yang lama dapat menyebabkan nyamuk resisten.Penelitian ini bertujuan untuk mengetahui status resistensi nyamuk Aedes aegypti dari daerah pedesaan endemik di kabupaten Cimahi terhadap cypermethrin (pyretroid sintetis. Metode : mengetahui

  8. STUDIES ON AEDES AEGYPTI RESISTANCE TO SOME INSECTICIDES IN THE JAZAN DISTRICT, SAUDI ARABIA.

    Science.gov (United States)

    Alsheikh, Adel A; Mohammed, W S; Noureldin, E M; Daffalla, O M; Shrwani, Y A; Hobani, K J; Alsheikh, F A; Alzahrani, M H; Binsaeed, A A

    2016-04-01

    The present study provided information on the susceptibility status of the adult and larvae of Aedes aegypti mosquitoes in Jazan region of Saudi Arabia. Bioassay tests were performed on adults and larvae by using WHO recommended concentrations and test kits. Adults of Ae. aegypti mosquitoes were exposed to test papers impregnated with Lambda-cyhalothrin (0.05%), Cyfluthrin (0.15%), Deltamethrin (0.05%), Permethrin (0.75%), Fenitrothion (1%), Bendiocarb (0.1%) and DDT (4%) insecticides. Ae. aegypti mosquitoes were found to be susceptible only to Cyfluthrin; (mortality rate was 100%), whereas variable resistances were observed from the rest of the other insecticides tested (mortality rates ranged between 93.6 and 17%). Larvae were subjected to different concentrations of Diflubenzuron, Methoprene (IGRs) and Temephos (Organophosphate). Adult emergence inhibition (IE₅₀ & IE₉₅) values for the IGRs and the (LC₅₀ & LC₉₅) for Temephos were determined by log-probit regression analysis. Ae. aegypti larvae were resistant to Temephos (LC₅₀ 61.8-LC₉₅ 35600.1 mg/l) and showed high susceptibility to Methoprene than Diflubenzuron (IE₅₀ 0.49-IE₉₅ 10.9 mg/l) and (IE₅₀ 0.86 and IE₉₅ 93.8 mg/l), respectively. Larvae were more susceptible to Methoprene than Diflubenzuron by 1.8 folds.

  9. STUDIES ON AEDES AEGYPTI RESISTANCE TO SOME INSECTICIDES IN THE JAZAN DISTRICT, SAUDI ARABIA.

    Science.gov (United States)

    Alsheikh, Adel A; Mohammed, W S; Noureldin, E M; Daffalla, O M; Shrwani, Y A; Hobani, K J; Alsheikh, F A; Alzahrani, M H; Binsaeed, A A

    2016-04-01

    The present study provided information on the susceptibility status of the adult and larvae of Aedes aegypti mosquitoes in Jazan region of Saudi Arabia. Bioassay tests were performed on adults and larvae by using WHO recommended concentrations and test kits. Adults of Ae. aegypti mosquitoes were exposed to test papers impregnated with Lambda-cyhalothrin (0.05%), Cyfluthrin (0.15%), Deltamethrin (0.05%), Permethrin (0.75%), Fenitrothion (1%), Bendiocarb (0.1%) and DDT (4%) insecticides. Ae. aegypti mosquitoes were found to be susceptible only to Cyfluthrin; (mortality rate was 100%), whereas variable resistances were observed from the rest of the other insecticides tested (mortality rates ranged between 93.6 and 17%). Larvae were subjected to different concentrations of Diflubenzuron, Methoprene (IGRs) and Temephos (Organophosphate). Adult emergence inhibition (IE₅₀ & IE₉₅) values for the IGRs and the (LC₅₀ & LC₉₅) for Temephos were determined by log-probit regression analysis. Ae. aegypti larvae were resistant to Temephos (LC₅₀ 61.8-LC₉₅ 35600.1 mg/l) and showed high susceptibility to Methoprene than Diflubenzuron (IE₅₀ 0.49-IE₉₅ 10.9 mg/l) and (IE₅₀ 0.86 and IE₉₅ 93.8 mg/l), respectively. Larvae were more susceptible to Methoprene than Diflubenzuron by 1.8 folds. PMID:27363057

  10. On the analysis of parasite effect for Aedes aegypti and Aedes albopictus population

    Science.gov (United States)

    Kallista, Meta; Aldila, Dipo; Nuraini, Nuning; Soewono, Edy

    2014-03-01

    It has been reported in some countries that the population of Aedes aegypti has been significantly reduced by the invasion of Aedes albopictus. There has been a hypothesis explaining this phenomenon of which investigated the influence of parasites pathogenesis to the competition between these two mosquito species in the fields. Ascogregarina taiwanensis and Ascogregarina culicis are known as parasites that infect Aedes albopictus and Aedes aegypti, respectively. Several studies have concluded that Ascogregarina taiwanensis caused high fatality for Aedes aegypti larvae, but Ascogregarina culicis was not pathogenic to Aedes albopictus larvae. Therefore, Ascogregarina taiwanensis may contribute to reduce the number of populations Aedes aegypti in the fields. Inspired by these facts, a mathematical model depicting interaction between parasites and mosquitoes is constructed in this paper. In this model are included six dynamic mosquito compartments, i.e. egg, larvae, infected larvae, adult, infected adult and one dynamic compartment for parasite. Derivation of the existence criteria and the stability analysis of parasite-free equilibrium as well as the basic offspring for the model are presented. Numerical simulations for sensitivity analysis indicating the invasive species for variation parameters are shown.

  11. Local Mosquito-Borne Transmission of Zika Virus - Miami-Dade and Broward Counties, Florida, June-August 2016.

    Science.gov (United States)

    Likos, Anna; Griffin, Isabel; Bingham, Andrea M; Stanek, Danielle; Fischer, Marc; White, Stephen; Hamilton, Janet; Eisenstein, Leah; Atrubin, David; Mulay, Prakash; Scott, Blake; Jenkins, Patrick; Fernandez, Danielle; Rico, Edhelene; Gillis, Leah; Jean, Reynald; Cone, Marshall; Blackmore, Carina; McAllister, Janet; Vasquez, Chalmers; Rivera, Lillian; Philip, Celeste

    2016-01-01

    During the first 6 months of 2016, large outbreaks of Zika virus disease caused by local mosquito-borne transmission occurred in Puerto Rico and other U.S. territories, but local mosquito-borne transmission was not identified in the continental United States (1,2). As of July 22, 2016, the Florida Department of Health had identified 321 Zika virus disease cases among Florida residents and visitors, all occurring in either travelers from other countries or territories with ongoing Zika virus transmission or sexual contacts of recent travelers.* During standard case investigation of persons with compatible illness and laboratory evidence of recent Zika virus infection (i.e., a specimen positive by real-time reverse transcription-polymerase chain reaction [rRT-PCR], or positive Zika immunoglobulin M [IgM] with supporting dengue serology [negative for dengue IgM antibodies and positive for dengue IgG antibodies], or confirmation of Zika virus neutralizing antibodies by plaque reduction neutralization testing [PRNT]) (3), four persons were identified in Broward and Miami-Dade counties whose infections were attributed to likely local mosquito-borne transmission. Two of these persons worked within 120 meters (131 yards) of each other but had no other epidemiologic connections, suggesting the possibility of a local community-based outbreak. Further epidemiologic and laboratory investigations of the worksites and surrounding neighborhood identified a total of 29 persons with laboratory evidence of recent Zika virus infection and likely exposure during late June to early August, most within an approximate 6-block area. In response to limited impact on the population of Aedes aegypti mosquito vectors from initial ground-based mosquito control efforts, aerial ultralow volume spraying with the organophosphate insecticide naled was applied over a 10 square-mile area beginning in early August and alternated with aerial larviciding with Bacillus thuringiensis subspecies

  12. Local Mosquito-Borne Transmission of Zika Virus - Miami-Dade and Broward Counties, Florida, June-August 2016.

    Science.gov (United States)

    Likos, Anna; Griffin, Isabel; Bingham, Andrea M; Stanek, Danielle; Fischer, Marc; White, Stephen; Hamilton, Janet; Eisenstein, Leah; Atrubin, David; Mulay, Prakash; Scott, Blake; Jenkins, Patrick; Fernandez, Danielle; Rico, Edhelene; Gillis, Leah; Jean, Reynald; Cone, Marshall; Blackmore, Carina; McAllister, Janet; Vasquez, Chalmers; Rivera, Lillian; Philip, Celeste

    2016-01-01

    During the first 6 months of 2016, large outbreaks of Zika virus disease caused by local mosquito-borne transmission occurred in Puerto Rico and other U.S. territories, but local mosquito-borne transmission was not identified in the continental United States (1,2). As of July 22, 2016, the Florida Department of Health had identified 321 Zika virus disease cases among Florida residents and visitors, all occurring in either travelers from other countries or territories with ongoing Zika virus transmission or sexual contacts of recent travelers.* During standard case investigation of persons with compatible illness and laboratory evidence of recent Zika virus infection (i.e., a specimen positive by real-time reverse transcription-polymerase chain reaction [rRT-PCR], or positive Zika immunoglobulin M [IgM] with supporting dengue serology [negative for dengue IgM antibodies and positive for dengue IgG antibodies], or confirmation of Zika virus neutralizing antibodies by plaque reduction neutralization testing [PRNT]) (3), four persons were identified in Broward and Miami-Dade counties whose infections were attributed to likely local mosquito-borne transmission. Two of these persons worked within 120 meters (131 yards) of each other but had no other epidemiologic connections, suggesting the possibility of a local community-based outbreak. Further epidemiologic and laboratory investigations of the worksites and surrounding neighborhood identified a total of 29 persons with laboratory evidence of recent Zika virus infection and likely exposure during late June to early August, most within an approximate 6-block area. In response to limited impact on the population of Aedes aegypti mosquito vectors from initial ground-based mosquito control efforts, aerial ultralow volume spraying with the organophosphate insecticide naled was applied over a 10 square-mile area beginning in early August and alternated with aerial larviciding with Bacillus thuringiensis subspecies

  13. Aedes aegypti uses RNA interference in defense against Sindbis virus infection

    Directory of Open Access Journals (Sweden)

    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.

  14. Sustained reduction in prevalence of lymphatic filariasis infection in spite of missed rounds of mass drug administration in an area under mosquito nets for malaria control

    Directory of Open Access Journals (Sweden)

    Shimada Masaaki

    2011-05-01

    Full Text Available Abstract Background The Global Programme to Eliminate Lymphatic Filariasis (GPELF was established by the World Health Organisation (WHO in 2000 with the goal of eliminating lymphatic filariasis (LF as a public health problem globally by 2020. Mass drug administration (MDA of antifilarial drugs is the principal strategy recommended for global elimination. Kenya launched a National Programme for Elimination of Lymphatic Filariasis (NPELF in Coast Region in 2002. During the same year a longitudinal research project to monitor trends of LF infection during MDA started in a highly endemic area in Malindi District. High coverage of insecticide treated nets (ITNs in the coastal region has been associated with dramatic decline in hospital admissions due to malaria; high usage of ITNs is also expected to have an impact on LF infection, also transmitted by mosquitoes. Results Four rounds of MDA with diethylcarbamazine citrate (DEC and albendazole were given to 8 study villages over an 8-year period. Although annual MDA was not administered for several years the overall prevalence of microfilariae declined significantly from 20.9% in 2002 to 0.9% in 2009. Similarly, the prevalence of filarial antigenaemia declined from 34.6% in 2002 to 10.8% in 2009. All the examined children born since the start of the programme were negative for filarial antigen in 2009. Conclusions Despite the fact that the study villages missed MDA in some of the years, significant reductions in infection prevalence and intensity were observed at each survey. More importantly, there were no rebounds in infection prevalence between treatment rounds. However, because of confounding variables such as insecticide-treated bed nets (ITNs, it is difficult to attribute the reduction to MDA alone as ITNs can lead to a significant reduction in exposure to filariasis vectors. The results indicate that national LF elimination programmes should be encouraged to continue provision of MDA albeit

  15. Aedes aegypti (L.) in Latin American and Caribbean region: With growing evidence for vector adaptation to climate change?

    Science.gov (United States)

    Chadee, Dave D; Martinez, Raymond

    2016-04-01

    Within Latin America and the Caribbean region the impact of climate change has been associated with the effects of rainfall and temperature on seasonal outbreaks of dengue but few studies have been conducted on the impacts of climate on the behaviour and ecology of Aedes aegypti mosquitoes.This study was conducted to examine the adaptive behaviours currently being employed by A. aegypti mosquitoes exposed to the force of climate change in LAC countries. The literature on the association between climate and dengue incidence is small and sometimes speculative. Few laboratory and field studies have identified research gaps. Laboratory and field experiments were designed and conducted to better understand the container preferences, climate-associated-adaptive behaviour, ecology and the effects of different temperatures and light regimens on the life history of A. aegypti mosquitoes. A. aegypti adaptive behaviours and changes in container preferences demonstrate how complex dengue transmission dynamics is, in different ecosystems. The use of underground drains and septic tanks represents a major behaviour change identified and compounds an already difficult task to control A. aegypti populations. A business as usual approach will exacerbate the problem and lead to more frequent outbreaks of dengue and chikungunya in LAC countries unless both area-wide and targeted vector control approaches are adopted. The current evidence and the results from proposed transdisciplinary research on dengue within different ecosystems will help guide the development of new vector control strategies and foster a better understanding of climate change impacts on vector-borne disease transmission.

  16. Aedes aegypti (L.) in Latin American and Caribbean region: With growing evidence for vector adaptation to climate change?

    Science.gov (United States)

    Chadee, Dave D; Martinez, Raymond

    2016-04-01

    Within Latin America and the Caribbean region the impact of climate change has been associated with the effects of rainfall and temperature on seasonal outbreaks of dengue but few studies have been conducted on the impacts of climate on the behaviour and ecology of Aedes aegypti mosquitoes.This study was conducted to examine the adaptive behaviours currently being employed by A. aegypti mosquitoes exposed to the force of climate change in LAC countries. The literature on the association between climate and dengue incidence is small and sometimes speculative. Few laboratory and field studies have identified research gaps. Laboratory and field experiments were designed and conducted to better understand the container preferences, climate-associated-adaptive behaviour, ecology and the effects of different temperatures and light regimens on the life history of A. aegypti mosquitoes. A. aegypti adaptive behaviours and changes in container preferences demonstrate how complex dengue transmission dynamics is, in different ecosystems. The use of underground drains and septic tanks represents a major behaviour change identified and compounds an already difficult task to control A. aegypti populations. A business as usual approach will exacerbate the problem and lead to more frequent outbreaks of dengue and chikungunya in LAC countries unless both area-wide and targeted vector control approaches are adopted. The current evidence and the results from proposed transdisciplinary research on dengue within different ecosystems will help guide the development of new vector control strategies and foster a better understanding of climate change impacts on vector-borne disease transmission. PMID:26796862

  17. Alterations in the Aedes aegypti transcriptome during infection with West Nile, dengue and yellow fever viruses.

    Directory of Open Access Journals (Sweden)

    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.

  18. Potential for Extrinsic Incubation Temperature to Alter Interplay Between Transmission Potential and Mortality of Dengue-Infected Aedes aegypti

    Science.gov (United States)

    Christofferson, Rebecca C.; Mores, Christopher N.

    2016-01-01

    The extrinsic incubation period is a critical component in the assessment of arboviral transmission potential. It defines the time it takes for a mosquito to become infectious following exposure to an arbovirus. Since this is a temporal process, the lifespan of a mosquito is intimately tied to the extrinsic incubation period and thus transmission potential of these viruses. Temperature is a known effector of both vector competence (the ability of a vector to transmit a pathogen) and mosquito mortality, but the interaction among temperature, vector competence, and mosquito mortality is not well characterized. Herein, we investigate this interaction for dengue virus, serotype 2, and its primary vector Aedes aegypti where we found that at 30 °C, infection and/or dissemination shortened the average lifespan of the mosquito and that when considering only mosquitoes with a disseminated infection, those incubated at 26 °C lived significantly longer.

  19. Potential for Extrinsic Incubation Temperature to Alter Interplay Between Transmission Potential and Mortality of Dengue-Infected Aedes aegypti.

    Science.gov (United States)

    Christofferson, Rebecca C; Mores, Christopher N

    2016-01-01

    The extrinsic incubation period is a critical component in the assessment of arboviral transmission potential. It defines the time it takes for a mosquito to become infectious following exposure to an arbovirus. Since this is a temporal process, the lifespan of a mosquito is intimately tied to the extrinsic incubation period and thus transmission potential of these viruses. Temperature is a known effector of both vector competence (the ability of a vector to transmit a pathogen) and mosquito mortality, but the interaction among temperature, vector competence, and mosquito mortality is not well characterized. Herein, we investigate this interaction for dengue virus, serotype 2, and its primary vector Aedes aegypti where we found that at 30 °C, infection and/or dissemination shortened the average lifespan of the mosquito and that when considering only mosquitoes with a disseminated infection, those incubated at 26 °C lived significantly longer. PMID:27478382

  20. Spatial and temporal country-wide survey of temephos resistance in Brazilian populations of Aedes aegypti.

    Science.gov (United States)

    Chediak, Mateus; G Pimenta, Fabiano; Coelho, Giovanini E; Braga, Ima A; Lima, José Bento P; Cavalcante, Karina Ribeiro Lj; Sousa, Lindemberg C de; Melo-Santos, Maria Alice V de; Macoris, Maria de Lourdes da G; Araújo, Ana Paula de; Ayres, Constância Flávia J; Andrighetti, Maria Teresa M; Gomes, Ricristhi Gonçalves de A; Campos, Kauara B; Guedes, Raul Narciso C

    2016-05-01

    The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites. PMID:27143489

  1. Spatial and temporal country-wide survey of temephos resistance in Brazilian populations of Aedes aegypti

    Science.gov (United States)

    Chediak, Mateus; G Pimenta, Fabiano; Coelho, Giovanini E; Braga, Ima A; Lima, José Bento P; Cavalcante, Karina Ribeiro LJ; de Sousa, Lindemberg C; de Melo-Santos, Maria Alice V; Macoris, Maria de Lourdes da G; de Araújo, Ana Paula; Ayres, Constância Flávia J; Andrighetti, Maria Teresa M; Gomes, Ricristhi Gonçalves de A; Campos, Kauara B; Guedes, Raul Narciso C

    2016-01-01

    The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites. PMID:27143489

  2. Insecticide susceptible/resistance status in Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera : Culicidae) in Thailand during 2003-2005

    OpenAIRE

    Jirakanjanakit, N.; Rongnoparut, P.; Saengtharatip, S.; T Chareonviriyaphap; Duchn, S.; Bellec, Christian; Yoksan, S

    2007-01-01

    Susceptibility baselines and diagnostic doses of the technical grade insecticides deltamethrin, permethrin, fenitrothion, and propoxur were established based on Aedes aegypti (L.), Bora (French Polynesia), a reference susceptible strain. Field-collected Aedes mosquitoes from each part of Thailand were subjected to bioassay for their susceptibility to the diagnostic doses of each insecticide. Almost all Ae. aegypti collected were incipient resistant or resistant to deltamethrin and permethrin,...

  3. Evaluation of the Larvicidal Efficacy of Five Indigenous Weeds against an Indian Strain of Dengue Vector, Aedes aegypti L. (Diptera: Culicidae)

    OpenAIRE

    Aarti Sharma; Sarita Kumar; Pushplata Tripathi

    2016-01-01

    Background and Objectives. Aedes aegypti, dengue fever mosquito, is primarily associated with the transmission of dengue and chikungunya in tropical and subtropical regions of the world. The present investigations were carried out to assess the larvicidal efficiency of five indigenous weeds against Ae. aegypti. Methods. The 1,000 ppm hexane and ethanol extracts prepared from the leaves and stem of five plants (Achyranthes aspera, Cassia occidentalis, Catharanthus roseus, Lantana camara, and X...

  4. 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...

  5. 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...

  6. Improving the effectiveness of three essential oils against Aedes aegypti (Linn.) and Anopheles dirus (Peyton and Harrison).

    Science.gov (United States)

    Auysawasdi, Nutthanun; Chuntranuluck, Sawitri; Phasomkusolsil, Siriporn; Keeratinijakal, Vichien

    2016-01-01

    Repellency of essential oil extracted from Curcuma longa, Eucalyptus globulus, and Citrus aurantium at various concentrations (5, 10, 15, 20, and 25 %) with and without 5 % vanillin was evaluated against female mosquitoes: Aedes aegypti and Anopheles dirus. The comparisons were made with a commercial chemical repellent (N,N-diethyl-3-methylbenzamide (DEET) 25 % w/w; KOR YOR 15) by arm in cage method. It was found that the essential oils with 5 % vanillin gave the longest lasting period against two mosquitoes as follows: Curcuma longa gave 150 min for Ae. aegypti, 480 min for An. dirus; Eucalyptus globulus gave 144 min for Ae. aegypti, 390 min for An. dirus; and Citrus aurantium gave 120 min for Ae. aegypti, 360 min for An. dirus. The 25 % Curcuma longa essential oil exhibited the best efficiency as equal as a commercial repellent (480 min against An. dirus). Vanillin can extend the period of time in protection against the two mosquitoes. This study indicates the potential uses of the essential oils (Curcuma longa, Eucalyptus globulus, and Citrus aurantium) with vanillin as natural mosquito repellents. PMID:26358103

  7. 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 bac

  8. Vacant Lots: Productive Sites for Aedes (Stegomyia) aegypti (Diptera: Culicidae) in Mérida City, México

    Science.gov (United States)

    BAAK-BAAK, CARLOS M.; ARANA-GUARDIA, ROGER; CIGARROA-TOLEDO, NOHEMI; LOROÑO-PINO, MARÍA ALBA; REYES-SOLIS, GUADALUPE; MACHAIN-WILLIAMS, CARLOS; BEATY, BARRY J.; EISEN, LARS; GARCÍA-REJÓN, JULIÁN E.

    2014-01-01

    We assessed the potential for vacant lots and other non-residential settings to serve as source environments for Aedes (Stegomyia) aegypti (L.) in Mérida City, México. Mosquito immatures were collected, during November 2011 – June 2013, from residential premises (n = 156 site visits) and non-residential settings represented by vacant lots (50), parking lots (18), and streets/sidewalks (28). Collections totaled 46,025 mosquito immatures of 13 species. Ae. aegypti was the most commonly encountered species accounting for 81.0% of total immatures, followed by Culex quinquefasciatus Say (12.1%). Site visits to vacant lots (74.0%) were more likely to result in collection of Ae. aegypti immatures that residential premises (35.9%). Tires accounted for 75.5% of Ae. aegypti immatures collected from vacant lots. Our data suggest that vacant lots should be considered for inclusion in mosquito surveillance and control efforts in Mérida City, as they often are located near homes, commonly have abundant vegetation, and frequently harbor accumulations of small and large discarded water-holding containers that we now have demonstrated to serve as development sites for immature mosquitoes. Additionally, we present data for associations of immature production with various container characteristics, such as storage capacity, water quality and physical location in the environment. PMID:24724299

  9. Insecticidal, repellent and oviposition-deterrent activity of selected essential oils against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus.

    Science.gov (United States)

    Prajapati, Veena; Tripathi, A K; Aggarwal, K K; Khanuja, S P S

    2005-11-01

    Essential oils extracted from 10 medicinal plants were evaluated for larvicidal, adulticidal, ovicidal, oviposition-deterrent and repellent activities towards three mosquito species; Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus. The essential oils of Juniperus macropoda and Pimpinella anisum were highly effective as both larvicidal and ovicidal. The essential oil of P. anisum showed toxicity against 4th instar larvae of A. stephensi and A. aegypti with equivalent LD95 values of 115.7 microg/ml, whereas it was 149.7 microg/ml against C. quinquefasciatus larvae. Essential oils of Zingiber officinale and Rosmarinus officinalis were found to be ovicidal and repellent, respectively towards the three mosquito species. The essential oil of Cinnamomum zeylanicum resulted into highest repellent (RD95) values of 49.6, 53.9 and 44.2 mg/mat against A. stephensi, A. aegypti and C. quinquefasciatus, respectively apart from oviposition-deterrent potential. PMID:16051081

  10. First detection of natural infection of Aedes aegypti with Zika virus in Brazil and throughout South America

    Science.gov (United States)

    Ferreira-de-Brito, Anielly; Ribeiro, Ieda P; de Miranda, Rafaella Moraes; Fernandes, Rosilainy Surubi; Campos, Stéphanie Silva; da Silva, Keli Antunes Barbosa; de Castro, Marcia Gonçalves; Bonaldo, Myrna C; Brasil, Patrícia; Lourenço-de-Oliveira, Ricardo

    2016-01-01

    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. PMID:27706382

  11. Eliciting renal failure in mosquitoes with a small-molecule inhibitor of inward-rectifying potassium channels.

    Directory of Open Access Journals (Sweden)

    Rene Raphemot

    Full Text Available Mosquito-borne diseases such as malaria and dengue fever take a large toll on global health. The primary chemical agents used for controlling mosquitoes are insecticides that target the nervous system. However, the emergence of resistance in mosquito populations is reducing the efficacy of available insecticides. The development of new insecticides is therefore urgent. Here we show that VU573, a small-molecule inhibitor of mammalian inward-rectifying potassium (Kir channels, inhibits a Kir channel cloned from the renal (Malpighian tubules of Aedes aegypti (AeKir1. Injection of VU573 into the hemolymph of adult female mosquitoes (Ae. aegypti disrupts the production and excretion of urine in a manner consistent with channel block of AeKir1 and renders the mosquitoes incapacitated (flightless or dead within 24 hours. Moreover, the toxicity of VU573 in mosquitoes (Ae. aegypti is exacerbated when hemolymph potassium levels are elevated, suggesting that Kir channels are essential for maintenance of whole-animal potassium homeostasis. Our study demonstrates that renal failure is a promising mechanism of action for killing mosquitoes, and motivates the discovery of selective small-molecule inhibitors of mosquito Kir channels for use as insecticides.

  12. Evaluation of Mosquito Repellent Activity of Isolated Oleic Acid, Eicosyl Ester from Thalictrum javanicum

    OpenAIRE

    Abinaya Gurunathan; Jamuna Senguttuvan; S Paulsamy

    2016-01-01

    To evaluate the traditional use, the mosquito repellent property of Thalictrum javanicum and to confirm the predicted larvicidal activity of the isolated compound, oleic acid, eicosyl ester from its aerial parts by PASS software, the present study was carried out using 4th instar stage larvae of the mosquitoes, Aedes aegypti (dengue vector) and Culex quinquefasciatus (filarial vector). Insecticidal susceptibility tests were conducted and the mortality rate was observed after 24 h exposure. Th...

  13. Extensive circadian and light regulation of the transcriptome in the malaria mosquito Anopheles gambiae

    OpenAIRE

    Rund, Samuel SC; James E. Gentile; Duffield, Giles E.

    2013-01-01

    Background Mosquitoes exhibit 24 hr rhythms in flight activity, feeding, reproduction and development. To better understand the molecular basis for these rhythms in the nocturnal malaria vector Anopheles gambiae, we have utilized microarray analysis on time-of-day specific collections of mosquitoes over 48 hr to explore the coregulation of gene expression rhythms by the circadian clock and light, and compare these with the 24 hr rhythmic gene expression in the diurnal Aedes aegypti dengue vec...

  14. 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

    2016-09-01

    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

  15. Distribution and occurrence of mosquito species in the municipal areas of Imo State, Nigeria

    OpenAIRE

    Ifeyinwa Celestina MGBEMENA; Tochi EBE

    2012-01-01

    A study of the ecology of drainage - breeding mosquito vectors was conducted in the three urban centers (Owerri, Orlu and Okigwe) of Imo State, Nigeria. Four drainage sites located around markets, residential, stream and hotel premises were selected in each urban centre. Dipping method of sampling was employed and a total of 8,820 mosquitoes comprising eight species namely; Aedes aegypti, Aedes vittatus, Culex quinquefasciatus, Culex tigripes, Culex horridus, Culex cinereus, Culex annuliorus ...

  16. A device for monitoring and control of mosquitoes by behaviour manipulation.

    Science.gov (United States)

    Vartak, P H; Tungikar, V B; Sharma, R N

    1994-09-01

    A trap was designed and fabricated for capturing mosquito larvae based on their behavioural responses to food and light. The larvae upon entering the trap died ultimately due to asphyxiation. Maximum success was achieved with Aedes aegypti larvae in lesser water volumes. The usefulness of the device for studying the response of mosquito larvae and aquatic organisms to chemicals, baits, light, various stimuli and possible pest/vector monitoring and management in aquatic eco-system is discussed. PMID:7814048

  17. Comparative Susceptibility of Mosquito Populations in North Queensland, Australia to Oral Infection with Dengue Virus

    OpenAIRE

    Ye, Yixin H; Ng, Tat Siong; Frentiu, Francesca D.; Walker, Thomas; van den Hurk, Andrew F.; O' Neill, Scott L; Beebe, Nigel W; McGraw, Elizabeth A.

    2014-01-01

    Dengue is the most prevalent arthropod-borne virus, with at least 40% of the world's population at risk of infection each year. In Australia, dengue is not endemic, but viremic travelers trigger outbreaks involving hundreds of cases. We compared the susceptibility of Aedes aegypti mosquitoes from two geographically isolated populations to two strains of dengue virus serotype 2. We found, interestingly, that mosquitoes from a city with no history of dengue were more susceptible to virus than m...

  18. 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

  19. Evaluation of Andrographis paniculata Burm.f. (Family:Acanthaceae) extracts against Culex quinquefasciatus (Say.) and Aedes aegypti (Linn.) (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Marimuthu Govindarajan

    2011-01-01

    Objective:To investigate the larvicidal and ovicidal efficacy of different extracts of Andrographis paniculata (A. paniculata) against Culex quinquefasciatus (Cx. quinquefasciatus) Say and Aedes aegypti (Ae. aegypti ) L. (Diptera:Culicidae). Methods:Larvicidal efficacy of the crude leaf extracts of A. paniculata with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the early third instar larvae of Cx. quinquefasciatus and Ae. aegypti. The ovicidal activity was determined against two mosquito species to various concentrations ranging from 50-300 ppm under the laboratory conditions. Results:The benzene, hexane, ethyl acetate, methanol and chloroform leaf extract of A. paniculata was found to be more effective against Cx. quinquefasciatus than Ae. aegypti. The LC50 values were 112.19, 137.48, 118.67, 102.05, 91.20 ppm and 119.58, 146.34, 124.24, 110.12, 99.54 ppm respectively. Among five tested solvent, methanol and ethyl acetate crude extract was found to be most effective for ovicidal activity against two mosquito species. The extract of methanol and ethyl acetate exerted 100%mortality at 200 ppm against Cx. quinquefasciatus and at 250 ppm against Ae. aegypti. Conclusions:From the results it can be concluded the crude extract of A. paniculata was a potential for controlling Cx. quinquefasciatus and Ae. aegypti mosquitoes.

  20. Gene flow, subspecies composition, and dengue virus-2 susceptibility among Aedes aegypti collections in Senegal.

    Directory of Open Access Journals (Sweden)

    Massamba Sylla

    Full Text Available BACKGROUND: 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. METHODS AND FINDINGS: 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

  1. Repellents inhibit P450 enzymes in Stegomyia (Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    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.

  2. Curcuma Raktakanda is a Potential Larvicide for Mosquito Control.

    Science.gov (United States)

    Latha, C; Ammini, J

    2000-01-01

    The leaves and tuber of Curcuma raktakanda were investigated as a mosquito larvicide against the early fourth instar larvae of four mosquito species, viz., Culex quinquefasciatus , Culex sitiens , Aedes aegypti and Anopheles stephensi . The petroleum ether extract of the leaves and tuber exhibited toxicity towards all the test species. The LC 90 values of leaf extract for Cx. quinquefasciatus , Cx. sitiens , Ae. aegypti and An. stephensi were 46.77, 27.45, 58.75 and 45.81 mg/l,respectively. The LC 90 values of crude extract of tuber were 44.88, 29.11, 48.08 and 37.49 mg/l for Cx. quinquefasciatus , Cx. sitiens , Ae. aegypti and An. stephensi , respectively. The crude extract of the tuber was fractionated using column chromatography and the activity of the fractions was studied against the test species. The LC 90 values of the biologically active fraction for Cx. quinquefasciatus , Cx. sitiens , Ae. aegypti and An. stephensi were 18.50, 12.82, 19.95 and 18.19 mg/l, respectively. The extracts were active after storage for one year.

  3. 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.

  4. Larvicidal and Adulticidal Activity of Chroman and Chromene Analogues against Susceptible and Permethrin-Resistant Mosquito Strains.

    Science.gov (United States)

    Meepagala, Kumudini M; Estep, Alden S; Becnel, James J

    2016-06-22

    Mosquitoes play a major role as vectors that transmit parasitic and viral diseases worldwide, especially in tropical and subtropical countries. Mosquito borne diseases not only affect humans but they also affect livestock in many parts of the world. They carry diseases that are lethal to dogs and horses. Dog heartworm disease (Dirofilaria immitis) is a parasitic disease spread through mosquitoes. This disease is not limited to dogs, but it can affect other animals and humans as well. Eastern equine encephalitis (EEE) and West Nile virus (WNV) are also mosquito borne diseases that affect the central nervous system of horses and cause severe complications and death. Emergence of resistance among mosquitoes to current pesticides has increased the importance of the search for alternate compounds that are effective and environmentally benign with diverse modes of actions than those that are commercially available. Aedes aegypti mosquitoes are the primary vector for transmission of Zika viral fever, yellow fever, dengue fever, and chikungunya. Mosquito control is currently the best strategy to prevent mosquito borne diseases. There are numerous approaches for control of potentially dangerous mosquito populations. These approaches include the use of adulticides (insecticides), larvicides, and, to a limited extent, the use of repellents. Our previous studies have shown the mosquito repellent activity of chromenes. In the present study, we demonstrate larvicidal and adulticidal activity of chroman and chromene analogues against a permethrin susceptible laboratory strain as well as activity against a permethrin-resistant strain of Aedes aegypti. PMID:27249182

  5. Larvicidal and Adulticidal Activity of Chroman and Chromene Analogues against Susceptible and Permethrin-Resistant Mosquito Strains.

    Science.gov (United States)

    Meepagala, Kumudini M; Estep, Alden S; Becnel, James J

    2016-06-22

    Mosquitoes play a major role as vectors that transmit parasitic and viral diseases worldwide, especially in tropical and subtropical countries. Mosquito borne diseases not only affect humans but they also affect livestock in many parts of the world. They carry diseases that are lethal to dogs and horses. Dog heartworm disease (Dirofilaria immitis) is a parasitic disease spread through mosquitoes. This disease is not limited to dogs, but it can affect other animals and humans as well. Eastern equine encephalitis (EEE) and West Nile virus (WNV) are also mosquito borne diseases that affect the central nervous system of horses and cause severe complications and death. Emergence of resistance among mosquitoes to current pesticides has increased the importance of the search for alternate compounds that are effective and environmentally benign with diverse modes of actions than those that are commercially available. Aedes aegypti mosquitoes are the primary vector for transmission of Zika viral fever, yellow fever, dengue fever, and chikungunya. Mosquito control is currently the best strategy to prevent mosquito borne diseases. There are numerous approaches for control of potentially dangerous mosquito populations. These approaches include the use of adulticides (insecticides), larvicides, and, to a limited extent, the use of repellents. Our previous studies have shown the mosquito repellent activity of chromenes. In the present study, we demonstrate larvicidal and adulticidal activity of chroman and chromene analogues against a permethrin susceptible laboratory strain as well as activity against a permethrin-resistant strain of Aedes aegypti.

  6. Electroantennogram, flight orientation, and oviposition responses of Aedes aegypti to the oviposition pheromone n-heneicosane.

    Science.gov (United States)

    Seenivasagan, T; Sharma, Kavita R; Sekhar, K; Ganesan, K; Prakash, Shri; Vijayaraghavan, R

    2009-03-01

    Oviposition pheromones specifically influence the females of many insects to lay eggs in the sites resulting in more egg deposition. A previous report describes the principal role of n-heneicosane (C(21)) identified and characterized from the larval cuticle of Aedes aegypti (L.) in attracting the gravid mosquitoes to oviposit in treated substrates among other chemical components. However, the means by which this compound is perceived by the females for oviposition has not been reported. In this study, we have recorded the peripheral olfactory responses from the antenna of Ae. aegypti from 10(-7) g to 10(-3) g doses of n-heneicosane. The EAG response of female mosquitoes increased in a dose-dependent manner with increasing stimulus strength. In the orientation assay using Y-maze olfactometer, female mosquitoes were attracted to the odor plume of 10(-6) g and 10(-5) g dose, while the higher dose of 10(-3) g plume enforced repellency to gravid mosquitoes. The response to oviposition substrates by gravid Ae. aegypti females differed across the range of concentrations of n-heneicosane under multiple choice conditions, larger number of eggs were deposited in 10 ppm (10 mg/l) solutions compared to lower and higher concentrations indicating 10 ppm was most attractive. Application of n-heneicosane at 10 ppm in breeding habitats will be a useful method to attract the gravid mosquitoes using ovitraps for surveillance and monitoring. The possible use of this compound in monitoring of mosquito population in endemic areas in relevance to integrated vector management strategies is discussed in detail.

  7. Host-pathogen interactions and genome evolution in two generalist and specialist microsporidian pathogens of mosquitoes

    Science.gov (United States)

    The adaptation of two distantly related microsporidia to their mosquito hosts was investigated. Edhazardia aedis is a specialist pathogen that infects Aedes aegypti, the main vector of dengue and yellow fever arboviruses. Vavraia culicis is a generalist pathogen of several insects including Anophele...

  8. Spatial Patterns of High Aedes aegypti Oviposition Activity in Northwestern Argentina

    Science.gov (United States)

    Estallo, Elizabet Lilia; Más, Guillermo; Vergara-Cid, Carolina; Lanfri, Mario Alberto; Ludueña-Almeida, Francisco; Scavuzzo, Carlos Marcelo; Introini, María Virginia; Zaidenberg, Mario; Almirón, Walter Ricardo

    2013-01-01

    Background In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. Methodology Oviposition activity was detected in Orán City (Salta province) using ovitraps, weekly replaced (October 2005–2007). Spatial autocorrelation was measured with Moran’s Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR) sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. Principal Findings Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC = 0.77), obtaining 99% of sensitivity and 75.29% of specificity. Conclusions Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist National Health

  9. Spatial patterns of high Aedes aegypti oviposition activity in northwestern Argentina.

    Directory of Open Access Journals (Sweden)

    Elizabet Lilia Estallo

    Full Text Available BACKGROUND: In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. METHODOLOGY: Oviposition activity was detected in Orán City (Salta province using ovitraps, weekly replaced (October 2005-2007. Spatial autocorrelation was measured with Moran's Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. PRINCIPAL FINDINGS: Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC=0.77, obtaining 99% of sensitivity and 75.29% of specificity. CONCLUSIONS: Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist

  10. Screening of Methanolic Plant Extracts against Larvae of Aedes aegypti and Anopheles stephensi in Mysore

    Directory of Open Access Journals (Sweden)

    Thirumalapura Krishnaiah Mohankumar

    2016-01-01

    Full Text Available Background: Mosquitoes transmit serious human diseases, causing millions of death every year. Vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. Nine different locally available medicinally important plants suspected to posse larvicidal property were screened against fourth instar larvae of Aedes aegypti and Anoph­eles stephensi to a series of concentrations of the methanolic extracts.Methods: Susceptibility tests on Ae. aegypti and An. stephensi were conducted using standard WHO methods. The larvae of two mosquito species were exposed to methanolic extracts and mortality counts were made after 24 hours of exposure as per WHO method. Larvae of Ae. aegypti were more susceptible than that of An. stephensi.Results: Among the nine plant species tested, Annona reticulata leaf extract was more effective against Ae. aegypti larvae with LC50 and LC90 values of 95.24 and 262.64 ppm respectively and against An. stephensi larvae 262.71 and 636.94 ppm respectively. The least efficacy was in Cosmos bipinnatus with LC50 and LC90 values of 442.6 and 1225.93 ppm against Ae. aegypti and LC50 and LC90 values of 840.69 and 1334.01 ppm of Thespesia populnea against An. stephensi.Conclusion: The crude methanolic extract of the An. reticulata with good larvicidal efficacy could be considered for further characterization to control mosquito vectors instead of chemical insecticides. High efficacy found in An. re­ticulata extract will be considered for further studies to isolate the bioactive compound.

  11. Bdelloid rotifer, Philodina species in the breeding containers of Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Muniaraj, M; Arunachalam, N; Paramasivan, R; Mariappan, T; Philip Samuel, P; Rajamannar, V

    2012-12-01

    The vector mosquitoes of dengue and chikungunya fever, Aedes aegypti and Aedes albopictus have adapted to feed on humans and undergo larval and pupal development in natural and artificial freshwater collections. Although several studies reported, still, much information is required to understand the successful survival of Aedes mosquitoes in small temporary containers. In an investigation conducted in the chikungunya affected areas of Kerala state, India, the presence of Bdelloid rotifer, Philodina in 95% of breeding habitats of Ae. aegypti and Ae. albopictus was recorded. The role of Philodina in the breeding containers was investigated. It was found that while in control the number of Philodina was found increasing in the water sample during the study period of seven days, the number found decreased in the containers with larvae of Aedes. The gut content analysis also confirmed the presence of the rotating wheel, corona of Philodina in some of the specimen suggests its role as major larval food. PMID:23202612

  12. Effect of Wolbachia on insecticide susceptibility in lines of Aedes aegypti.

    Science.gov (United States)

    Endersby, N M; Hoffmann, A A

    2013-06-01

    Two stable infections of Wolbachia pipientis, wMelPop and wMel, now established in Aedes aegypti, are being used in a biocontrol program to suppress the transmission of dengue. Any effects of Wolbachia infection on insecticide resistance of mosquitoes may undermine the success of this program. Bioassays of Ae. aegypti were conducted to test for differences in response to insecticides between Wolbachia infected (wMelPop, wMel) and uninfected lines. Insecticides screened were bifenthrin, the pyrethroid commonly used for adult knockdown, as well as larvicides: Bacillus thuringiensis var. israelensis, the organophosphate, temephos and the insect growth regulator, s-methoprene. While differences in response between lines were detected for some insecticides, no obvious or consistent effects related to presence of Wolbachia infection were observed. Spreading Wolbachia infections are, therefore, unlikely to affect the efficacy of traditional chemical control of mosquito outbreaks. PMID:23149015

  13. Insecticidal and repellent activity of Siparuna guianensis Aubl. (Negramina) against Aedes aegypti and Culex quinquefasciatus.

    Science.gov (United States)

    Aguiar, Raimundo Wagner Souza; dos Santos, Suetonio Fernandes; da Silva Morgado, Fabricio; Ascencio, Sergio Donizeti; de Mendonça Lopes, Magnólia; Viana, Kelvinson Fernandes; Didonet, Julcemar; Ribeiro, Bergmann Morais

    2015-01-01

    This study investigated the toxic effects of essential oils isolated from Siparuna guianensis against Aedes aegypti, Culex quinquefasciatus (eggs, larvae, pupae, and adult) and Aedes albopictus (C6/36) cells. The oviposition-deterring activity, egg viability, and repellence activity in the presence of different essential oils concentrations were determined. The essential oils showed high toxicity to all developmental stages of A. aegypti and C. quinquefasciatus. Furthermore, the oils also showed high repellent activity towards the adult stage of mosquitoes (0.025 to 0.550 μg/cm2 skin conferred 100% repellence up to 120 min) and in contact with cultured insect cells (C6/36) induced death possibly by necrosis. The results presented in this work show the potential of S. guianensis essential oils for the development of an alternative and effective method for the natural control of mosquitoes in homes and urban areas.

  14. Host-feeding pattern of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in heterogeneous landscapes of South Andaman, Andaman and Nicobar Islands, India.

    Science.gov (United States)

    Sivan, Arun; Shriram, A N; Sunish, I P; Vidhya, P T

    2015-09-01

    Mosquito foraging behavior is a determinant of host-vector contact and has an impact on the risk of arboviral epidemics. Therefore, blood-feeding patterns is a useful tool for assessing the role in pathogen transmission by vector mosquitoes. Competent vectors of dengue and chikungunya viz. Aedes aegypti and Aedes albopictus are widely prevalent in the Andaman and Nicobar archipelago. Considering the vector potential, medical importance of both these mosquito species and lack of information on host-feeding patterns, blood meal analysis of both these vector mosquitoes was undertaken. Biogents Sentinel traps were used for sampling blooded mosquitoes, for identifying the source of blood meal by agar gel-precipitin test. We identified vertebrate source of 147 and 104 blood meals in Ae. aegypti and Ae. albopictus from heterogeneous landscapes in South Andaman district. Results revealed that Ae. aegypti (88 %) and Ae. albopictus (49 %) fed on human and a small proportion on mammals and fowls, indicative of predominance of anthropophilism. Ae. aegypti predominantly fed on human blood (94.2 %-densely built urban, 89.8 %-low vegetation coverage, and 78.3 %-medium vegetation coverage). Anthropophilism in Ae. albopictus was maximal in densely built urban (90.5 %) and progressively decreased from low vegetation-vegetation/forested continuum (66.7, 36.4, and 8.7 %), indicating plasticity in feeding across these landscapes. Epidemiological significance of the findings is discussed. PMID:26220560

  15. Using Wolbachia Releases to Estimate Aedes aegypti (Diptera: Culicidae) Population Size and Survival.

    Science.gov (United States)

    Garcia, Gabriela de Azambuja; Dos Santos, Lilha Maria Barbosa; Villela, Daniel Antunes Maciel; Maciel-de-Freitas, Rafael

    2016-01-01

    Mosquitoes carrying the endosymbiont bacterium Wolbachia have been deployed in field trials as a biological control intervention due to Wolbachia effects on reducing transmission of arboviruses. We performed mark, release and recapture (MRR) experiments using Wolbachia as an internal marker with daily collections with BG-Traps during the first two weeks of releases in Rio de Janeiro, Brazil. The MRR design allowed us to investigate two critical parameters that determine whether Wolbachia would successful invade a field population: the probability of daily survival (PDS) of Wolbachia-infected Aedes aegypti females, and the wild population density during releases. Released females had a PDS of 0.82 and 0.89 in the first and second weeks, respectively, immediately after releases, which is well within the range of previous estimates of survivorship of wild mosquitoes in Rio de Janeiro. Abundance estimation of wild population varied up to 10-fold higher depending on the estimation method used (634-3565 females on the average-difference model to 6365-16188 females according to Lincoln-Petersen). Wolbachia-released mosquitoes were lower than the density estimation of their wild counterparts, irrespectively of the model used. Individually screening mosquitoes for the presence of Wolbachia reduced uncertainty on abundance estimations due to fluctuation in capturing per week. A successful invasion into local population requires Ae. aegypti fitness is unaffected by Wolbachia presence, but also reliable estimates on the population size of wild mosquitoes. PMID:27479050

  16. Human-Mediated Marine Dispersal Influences the Population Structure of Aedes aegypti in the Philippine Archipelago.

    Directory of Open Access Journals (Sweden)

    Eugenio Fonzi

    Full Text Available Dengue virus (DENV is an extraordinary health burden on global scale, but still lacks effective vaccine. The Philippines is endemic for dengue fever, but massive employment of insecticides favored the development of resistance mutations in its major vector, Aedes aegypti. Alternative vector control strategies consist in releasing artificially modified mosquitos in the wild, but knowledge on their dispersal ability is necessary for a successful implementation. Despite being documented that Ae. aegypti can be passively transported for long distances, no study to date has been aimed at understanding whether human marine transportation can substantially shape the migration patterns of this mosquito. With thousands of islands connected by a dense network of ships, the Philippines is an ideal environment to fill this knowledge gap.Larvae of Ae. aegypti from 15 seaports in seven major islands of central-western Philippines were collected and genotyped at seven microsatellite loci. Low genetic structure and considerable gene flow was found in the area. Univariate and multivariate regression analyses suggested that anthropic factors (specifically the amount of processed cargo and human population density can explain the observed population structure, while geographical distance was not correlated. Interestingly, cargo shipments seem to be more efficient than passenger ships in transporting Ae. aegypti. Bayesian clustering confirmed that Ae. aegypti from busy ports are more genetically similar, while populations from idle ports are relatively structured, regardless of the geographical distance that separates them.The results confirmed the pivotal role of marine human-mediated long-range dispersal in determining the population structure of Ae. aegypti. Hopefully corroborated by further research, the present findings could assist the design of more effective vector control strategies.

  17. Contact irritant responses of Aedes aegypti Using sublethal concentration and focal application of pyrethroid chemicals.

    Directory of Open Access Journals (Sweden)

    Hortance Manda

    Full Text Available BACKGROUND: Previous studies have demonstrated contact irritant and spatial repellent behaviors in Aedes aegypti following exposure to sublethal concentrations of chemicals. These sublethal actions are currently being evaluated in the development of a push-pull strategy for Ae. aegypti control. This study reports on mosquito escape responses after exposure to candidate chemicals for a contact irritant focused push-pull strategy using varying concentrations and focal application. METHODS: Contact irritancy (escape behavior, knockdown and 24 hour mortality rates were quantified in populations of female Ae. aegypti under laboratory conditions and validated in the field (Thailand and Peru using experimental huts. Evaluations were conducted using varying concentrations and treatment surface area coverage (SAC of three pyrethroid insecticides: alphacypermethrin, lambacyhalothrin and deltamethrin. RESULTS: Under laboratory conditions, exposure of Ae. aegypti to alphacypermethrin using the standard field application rate (FAR resulted in escape responses at 25% and 50% SAC that were comparable with escape responses at 100% SAC. Significant escape responses were also observed at <100% SAC using ½FAR of all test compounds. In most trials, KD and 24 hour mortality rates were higher in mosquitoes that did not escape than in those that escaped. In Thailand, field validation studies indicated an early time of exit (by four hours and 40% increase in escape using ½FAR of alphacypermethrin at 75% SAC compared to a matched chemical-free control. In Peru, however, the maximum increase in Ae. aegypti escape from alphacypermethrin-treated huts was 11%. CONCLUSIONS/SIGNIFICANCE: Results presented here suggest a potential role for sublethal and focal application of contact irritant chemicals in an Ae. aegypti push-pull strategy to reduce human-vector contact inside treated homes. However, the impact of an increase in escape response on dengue virus transmission is

  18. Genetic profile and molecular resistance of Aedes (Stegomyia aegypti (Diptera: Culicidae in Foz do Iguaçu (Brazil, at the border with Argentina and Paraguay

    Directory of Open Access Journals (Sweden)

    Ana C. Dalla Bona

    2012-12-01

    Full Text Available The genetic variability of populations of Aedes (Stegomyia aegypti (Linnaeus, 1762 is often low due to the intense selection pressure caused by chemical control measures. In this study, we evaluated the susceptibility of larvae and adults of this mosquito to chemical insecticides, the frequency of the Val1016IIe mutation, and the genetic variability of the mitochondrial ND4 gene fragment in the urban area of Foz do Iguaçu, Paraná. The populations of A. aegypti in the southern and central regions of the city were resistant to the diagnostic dose of temephos 0.0162 ppm. Additionally, we detected difference in susceptibility in the northern population. The resistance ratios (RR95 were 3.8, 4.1, and 4.6 for the populations in the north, central, and south of the city, respectively. The entire population of A. aegypti in Foz do Iguaçu is resistant to pyrethroids. The mortality rates are as follows: 72.2% for cypermethrin (CD: 146 mg i.a./m² and 57% for deltamethrin (CD: 18 mg i.a./m². These results corroborate the hypothesis that the mutated 1016Ile allele is present in all analyzed strata. Out of the 234 samples genotyped for the Val1016Ile mutation, 15% were homozygous dominant for the wild allele (Val/Val, 62% were heterozygous (Va/Ile and 23% were homozygous for the recessive mutation (Ile/Ile. With respect to the genetic variability of the mitochondrial ND4 gene fragment, 93% of the sequences analyzed belonged to haplotype 1, and 7% belonged to haplotype 2. The genetic diversity was low, the fixation index was not significant, and gene flow was high. The control of A. aegypti in Foz do Iguaçu using temephos and pyrethroids may be compromised because of the reduced vector susceptibility. Populations of A. aegypti, that undergoes a sudden reduction in effective population size and become resistant to pyrethroids may differ from the original population in vector capacity.

  19. New Candidates for Plant-Based Repellents Against Aedes aegypti.

    Science.gov (United States)

    Misni, Norashiqin; Nor, Zurainee Mohamed; Ahmad, Rohani

    2016-06-01

    Based on an ethnobotanical study on use for plant species against mosquito bites in the Kota Tinggi District, Johor State, Malaysia, 3 plants selected for study, Citrus aurantifolia (leaves), Citrus grandis (fruit peel), and Alpinia galanga (rhizome), were extracted using hydrodistillation to produce essential oils. These essential oils were then formulated as a lotion using a microencapsulation process and then tested for their repellent effect against Aedes aegypti. N,N-diethyl-m-toluamide (deet) was also prepared in the same formulation and tested for repellency as controls. Four commercial plant-based repellent (KAPS(®), MozAway(®), BioZ Natural(®), and Mosiquard(®)) also were incorporated in the bioassay for comparison purposes. Bioassays revealed that at 20% concentration all repellent formulations demonstrated complete protection for 2 h and >90% for 4 h post-application. The A. galanga-based formulation provided the greatest level of protection (98.91%), which extended for 4 h post-application and was not significantly different from deet at similar concentration. When compared with commercial plant-based repellents (KAPS(®), MozAway(®), and BioZ Natural(®)), the 3 lotion formulations showed significantly better protection against Ae. aegypti bites, providing >90% protection for 4 h. In conclusion, our 3 plant-based lotion formulations provided acceptable levels of protection against host-seeking Ae. aegypti and should be developed. PMID:27280349

  20. Macroclimate determines the global range limit of Aedes aegypti.

    Science.gov (United States)

    Capinha, César; Rocha, Jorge; Sousa, Carla A

    2014-09-01

    Aedes aegypti is the main vector of dengue and a number of other diseases worldwide. Because of the domestic nature of this mosquito, the relative importance of macroclimate in shaping its distribution has been a controversial issue. We have captured here the worldwide macroclimatic conditions occupied by A. aegypti in the last century. We assessed the ability of this information to predict the species' observed distribution using supra-continental spatially-uncorrelated data. We further projected the distribution of the colonized climates in the near future (2010-2039) under two climate-change scenarios. Our results indicate that the macroclimate is largely responsible for setting the maximum range limit of A. aegypti worldwide and that in the near future, relatively wide areas beyond this limit will receive macroclimates previously occupied by the species. By comparing our projections, with those from a previous model based strictly on species-climate relationships (i.e., excluding human influence), we also found support for the hypothesis that much of the species' range in temperate and subtropical regions is being sustained by artificial environments. Altogether, these findings suggest that, if the domestic environments commonly exploited by this species are available in the newly suitable areas, its distribution may expand considerably in the near future. PMID:24643859

  1. Infection and transmission of Rift Valley fever viruses lacking the NSs and/or NSm genes in mosquitoes: potential role for NSm in mosquito infection.

    Directory of Open Access Journals (Sweden)

    Mary B Crabtree

    Full Text Available BACKGROUND: Rift Valley fever virus is an arthropod-borne human and animal pathogen responsible for large outbreaks of acute and febrile illness throughout Africa and the Arabian Peninsula. Reverse genetics technology has been used to develop deletion mutants of the virus that lack the NSs and/or NSm virulence genes and have been shown to be stable, immunogenic and protective against Rift Valley fever virus infection in animals. We assessed the potential for these deletion mutant viruses to infect and be transmitted by Aedes mosquitoes, which are the principal vectors for maintenance of the virus in nature and emergence of virus initiating disease outbreaks, and by Culex mosquitoes which are important amplification vectors. METHODOLOGY AND PRINCIPAL FINDINGS: Aedes aegypti and Culex quinquefasciatus mosquitoes were fed bloodmeals containing the deletion mutant viruses. Two weeks post-exposure mosquitoes were assayed for infection, dissemination, and transmission. In Ae. aegypti, infection and transmission rates of the NSs deletion virus were similar to wild type virus while dissemination rates were significantly reduced. Infection and dissemination rates for the NSm deletion virus were lower compared to wild type. Virus lacking both NSs and NSm failed to infect Ae. aegypti. In Cx. quinquefasciatus, infection rates for viruses lacking NSm or both NSs and NSm were lower than for wild type virus. CONCLUSIONS/SIGNIFICANCE: In both species, deletion of NSm or both NSs and NSm reduced the infection and transmission potential of the virus. Deletion of both NSs and NSm resulted in the highest level of attenuation of virus replication. Deletion of NSm alone was sufficient to nearly abolish infection in Aedes aegypti mosquitoes, indicating an important role for this protein. The double deleted viruses represent an ideal vaccine profile in terms of environmental containment due to lack of ability to efficiently infect and be transmitted by mosquitoes.

  2. Water Level Flux in Household Containers in Vietnam - A Key Determinant of Aedes aegypti Population Dynamics

    OpenAIRE

    Jeffery, Jason A. L.; Archie C.A. Clements; Yen Thi Nguyen; Le Hoang Nguyen; Son Hai Tran; Nghia Trung Le; Nam Sinh Vu; Ryan, Peter A; Kay, Brian H.

    2012-01-01

    We examined changes in the abundance of immature Aedes aegypti at the household and water storage container level during the dry-season (June-July, 2008) in Tri Nguyen village, central Vietnam. We conducted quantitative immature mosquito surveys of 171 containers in the same 41 households, with replacement of samples, every two days during a 29-day period. We developed multi-level mixed effects regression models to investigate container and household variability in pupal abundance. The percen...

  3. Aedes cadherin mediates the in vivo toxicity of the Cry11Aa toxin to Aedes aegypti.

    Science.gov (United States)

    Lee, Su-Bum; Chen, Jianwu; Aimanova, Karlygash G; Gill, Sarjeet S

    2015-06-01

    Cadherin plays an important role in the toxicity of Bacillus thuringiensis Cry proteins. We previously cloned a full-length cadherin from Aedes aegypti larvae and reported this protein binds Cry11Aa toxin from B. thuringiensis subsp. israelensis with high affinity, ≈16.7nM. Based on these results, we investigated if Aedes cadherin is involved in the in vivo toxicity of Cry11Aa toxin to Ae. aegypti. We established a mosquito cell line stably expressing the full-length Aedes cadherin and transgenic mosquitoes with silenced Aedes cadherin expression. Cells expressing the Aedes cadherin showed increased sensitivity to Cry11Aa toxin. Cry11Aa toxin at 400nM killed approximately 37% of the cells in 3h. Otherwise, transgenic mosquitoes with silenced Aedes cadherin expression showed increased tolerance to Cry11Aa toxin. Furthermore, cells expressing Aedes cadherin triggered Cry11Aa oligomerization. These results show the Aedes cadherin plays a pivotal role in Cry11Aa toxicity to Ae. aegypti larvae by mediating Cry11Aa oligomerization. However, since high toxicity was not obtained in cadherin-expressing cells, an additional receptor may be needed for manifestation of full toxicity. Moreover, cells expressing Aedes cadherin were sensitive to Cry4Aa and Cry11Ba, but not Cry4Ba. However transgenic mosquitoes with silenced Aedes cadherin expression showed no tolerance to Cry4Aa, Cry4Ba, and Cry11Ba toxins. These results suggest that while Aedes cadherin may mediate Cry4Aa and Cry11Ba toxicity, this cadherin but is not the main receptor of Cry4Aa, Cry4Ba and Cry11Ba toxin in Ae. aegypti.

  4. Insecticide-Driven Patterns of Genetic Variation in the Dengue Vector Aedes aegypti in Martinique Island

    OpenAIRE

    Sébastien Marcombe; Margot Paris; Christophe Paupy; Charline Bringuier; André Yebakima; Fabrice Chandre; Jean-Philippe David; Vincent Corbel; Laurence Despres

    2013-01-01

    Effective vector control is currently challenged worldwide by the evolution of resistance to all classes of chemical insecticides in mosquitoes. In Martinique, populations of the dengue vector Aedes aegypti have been intensively treated with temephos and deltamethrin insecticides over the last fifty years, resulting in heterogeneous levels of resistance across the island. Resistance spreading depends on standing genetic variation, selection intensity and gene flow among populations. To determ...

  5. Temephos Resistance in Aedes aegypti in Colombia Compromises Dengue Vector Control

    OpenAIRE

    Nelson Grisales; Rodolphe Poupardin; Santiago Gomez; Idalyd Fonseca-Gonzalez; Hilary Ranson; Audrey Lenhart

    2013-01-01

    BACKGROUND: Control and prevention of dengue relies heavily on the application of insecticides to control dengue vector mosquitoes. In Colombia, application of the larvicide temephos to the aquatic breeding sites of Aedes aegypti is a key part of the dengue control strategy. Resistance to temephos was recently detected in the dengue-endemic city of Cucuta, leading to questions about its efficacy as a control tool. Here, we characterize the underlying mechanisms and estimate the operational im...

  6. Multi-insecticide susceptibility evaluation of dengue vectors Stegomyia albopicta and St. aegypti in Assam, India

    OpenAIRE

    Yadav, Kavita; Rabha, Bipul; Dhiman, Sunil; Veer, Vijay

    2015-01-01

    Background Dengue is rapidly expanding mosquito-borne viral infection globally facing operational challenges due to insecticide resistance in dengue vectors. We have studied the susceptibility status of potential dengue vectors St. albopicta and St. aegypti to the commonly used insecticides. Methods Stegomyia larval bioassays were carried out to determine LC10, LC50 and LC99 values and resistance ratios (RR50 and RR99) for temephos. Adult susceptibility bioassay to 4% DDT, 0.05% deltamethrin,...

  7. Insecticide susceptibility of Aedes aegypti and Aedes albopictus in Central Africa

    OpenAIRE

    Nwane Philippe; Nchoutpouen Elysée; Chandre Fabrice; Marcombe Sébastien; Kamgang Basile; Etang Josiane; Corbel Vincent; Paupy Christophe

    2011-01-01

    Abstract Background Aedes aegypti (Linnaeus, 1762) and Aedes albopictus (Skuse, 1894) are the main vectors of dengue (DENV) and chikungunya (CHIKV) viruses worldwide. As there is still no vaccine or specific treatment for DENV and CHIKV, vector control remains the cornerstone of prevention and outbreak control. Unfortunately, vector control programs are facing operational challenges with mosquitoes becoming resistant to commonly used insecticides in several areas through the world. Throughout...

  8. Screening of Methanolic Plant Extracts against Larvae of Aedes aegypti and Anopheles stephensi in Mysore

    OpenAIRE

    Thirumalapura Krishnaiah Mohankumar; Kumuda Sathigal Shivanna; Vijayan Valiakottukal Achuttan

    2016-01-01

    Background: Mosquitoes transmit serious human diseases, causing millions of death every year. Vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. Nine different locally available medicinally important plants suspected to posse larvicidal property were screened against fourth instar larvae of Aedes aegypti and Anoph­eles stephensi to a series of co...

  9. PENENTUAN STATUS RESISTENSI Aedes aegypti DENGAN METODE SUSCEPTIBILITY DI KOTA CIMAHI TERHADAP CYPERMETHRIN

    OpenAIRE

    Firda Yanuar Pradani; Mara Ipa; Rina Marina; Yuneu Yuliasih

    2013-01-01

    ABSTRACT Background:  vector control of DBD usually doing by using insecticides, whether by government or insecticides used in household.  Using to much insecticides for long time can caused resistence of mosquito.  This research aim to know resistance status of Aedes aegypti from endemic rural in district Cimahi to cypermethrin (synthetic pyretroid). Methods:  resistance status knowing by susceptibility methods (WHO standard) with usingimpregnated paper that containing cypermethrin 0,2% and ...

  10. Aedes aegypti on Madeira Island (Portugal): genetic variation of a recently introduced dengue vector

    OpenAIRE

    Goncalo Seixas; Patricia Salgueiro; Ana Clara Silva; Melina Campos; Carine Spenassatto; Matias Reyes-Lugo; Maria Teresa Novo; Paulo Eduardo Martins Ribolla; Joao Pedro Soares da Silva Pinto; Carla Alexandra Sousa

    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 mosqui...

  11. Oviposition site selection by the dengue vector Aedes aegypti and its implications for dengue control.

    Directory of Open Access Journals (Sweden)

    Jacklyn Wong

    Full Text Available BACKGROUND: Because no dengue vaccine or antiviral therapy is commercially available, controlling the primary mosquito vector, Aedes aegypti, is currently the only means to prevent dengue outbreaks. Traditional models of Ae. aegypti assume that population dynamics are regulated by density-dependent larval competition for food and little affected by oviposition behavior. Due to direct impacts on offspring survival and development, however, mosquito choice in oviposition site can have important consequences for population regulation that should be taken into account when designing vector control programs. METHODOLOGY/PRINCIPAL FINDINGS: We examined oviposition patterns by Ae. aegypti among 591 naturally occurring containers and a set of experimental containers in Iquitos, Peru. Using larval starvation bioassays as an indirect measure of container food content, we assessed whether females select containers with the most food for their offspring. Our data indicate that choice of egg-laying site is influenced by conspecific larvae and pupae, container fill method, container size, lid, and sun exposure. Although larval food positively influenced oviposition, our results did not support the hypothesis that females act primarily to maximize food for larvae. Females were most strongly attracted to sites containing immature conspecifics, even when potential competitors for their progeny were present in abundance. CONCLUSION/SIGNIFICANCE: Due to strong conspecific attraction, egg-laying behavior may contribute more to regulating Ae. aegypti populations than previously thought. If highly infested containers are targeted for removal or larvicide application, females that would have preferentially oviposited in those sites may instead distribute their eggs among other suitable, previously unoccupied containers. Strategies that kill mosquitoes late in their development (i.e., insect growth regulators that kill pupae rather than larvae will enhance vector

  12. Dengue virus-infected Aedes aegypti in the home environment.

    Science.gov (United States)

    Garcia-Rejon, Julian; Loroño-Pino, Maria Alba; Farfan-Ale, Jose Arturo; Flores-Flores, Luis; Del Pilar Rosado-Paredes, Elsy; Rivero-Cardenas, Nubia; Najera-Vazquez, Rosario; Gomez-Carro, Salvador; Lira-Zumbardo, Victor; Gonzalez-Martinez, Pedro; Lozano-Fuentes, Saul; Elizondo-Quiroga, Darwin; Beaty, Barry J; Eisen, Lars

    2008-12-01

    We determined abundance of Aedes aegypti mosquitoes and presence of dengue virus (DENV) in females collected from premises of laboratory-confirmed dengue patients over a 12-month period (March 2007 to February 2008) in Merida, Mexico. Backpack aspiration from 880 premises produced 1,836 females and 1,292 males indoors (predominantly from bedrooms) and 102 females and 108 males from patios/backyards. The mean weekly indoor catch rate per home peaked at 7.8 females in late August. Outdoor abundances of larvae or pupae were not predictive of female abundance inside the home. DENV-infected Ae. aegypti females were recovered from 34 premises. Collection of DENV-infected females from homes of dengue patients up to 27 days after the onset of symptoms (median, 14 days) shows the usefulness of indoor insecticide application in homes of suspected dengue patients to prevent their homes from becoming sources for dispersal of DENV by persons visiting and being bitten by infected mosquitoes. PMID:19052309

  13. Towards the genetic manipulation of mosquito disease vectors

    International Nuclear Information System (INIS)

    Our research is aimed at developing the technologies necessary to undertake the genetic manipulation of insect vector genomes. In the longer term, we wish to explore the potential that this technology may have for developing novel strategies for the control of vector-borne diseases. The focus of our current research has been to: i) identify and characterise endogenous transposable elements in the genomes of mosquito vectors -research has focussed on identifying both Class I and Class 11 elements and determining their structure and distribution within mosquito genomes; ii) develop and use transfection systems for mosquito cells in culture as a test bed for transformation vectors and promoters - transfection techniques, vector constructs and different promoters driving reporter genes have been utilised to optimise the transformation of both Aedes aegypti and Anopheles gambiae cells in culture; iii) identify putative promoter sequences which are induced in the female mosquito midgut when it takes a blood meal - the Anopheles gambiae trypsin gene locus has been cloned and sequenced and the intergenic regions assessed for their ability to induce reporter gene expression in mosquito gut cells. The progress we have made in each of these areas will be described and discussed in the context of our longer term aim which is to introduce genes coding for antiparasitic agents into mosquito genomes in such a way that they are expressed in the mosquito midgut and disrupt transmission of the malaria parasite. (author)

  14. Analyzing mosquito (Diptera: culicidae diversity in Pakistan by DNA barcoding.

    Directory of Open Access Journals (Sweden)

    Muhammad Ashfaq

    Full Text Available BACKGROUND: Although they are important disease vectors mosquito biodiversity in Pakistan is poorly known. Recent epidemics of dengue fever have revealed the need for more detailed understanding of the diversity and distributions of mosquito species in this region. DNA barcoding improves the accuracy of mosquito inventories because morphological differences between many species are subtle, leading to misidentifications. METHODOLOGY/PRINCIPAL FINDINGS: Sequence variation in the barcode region of the mitochondrial COI gene was used to identify mosquito species, reveal genetic diversity, and map the distribution of the dengue-vector species in Pakistan. Analysis of 1684 mosquitoes from 491 sites in Punjab and Khyber Pakhtunkhwa during 2010-2013 revealed 32 species with the assemblage dominated by Culex quinquefasciatus (61% of the collection. The genus Aedes (Stegomyia comprised 15% of the specimens, and was represented by six taxa with the two dengue vector species, Ae. albopictus and Ae. aegypti, dominant and broadly distributed. Anopheles made up another 6% of the catch with An. subpictus dominating. Barcode sequence divergence in conspecific specimens ranged from 0-2.4%, while congeneric species showed from 2.3-17.8% divergence. A global haplotype analysis of disease-vectors showed the presence of multiple haplotypes, although a single haplotype of each dengue-vector species was dominant in most countries. Geographic distribution of Ae. aegypti and Ae. albopictus showed the later species was dominant and found in both rural and urban environments. CONCLUSIONS: As the first DNA-based analysis of mosquitoes in Pakistan, this study has begun the construction of a barcode reference library for the mosquitoes of this region. Levels of genetic diversity varied among species. Because of its capacity to differentiate species, even those with subtle morphological differences, DNA barcoding aids accurate tracking of vector populations.

  15. Global stability of a delayed mosquito-transmitted disease model with stage structure

    Directory of Open Access Journals (Sweden)

    B. G. Sampath Aruna Pradeep

    2015-01-01

    Full Text Available This article presents a new eco-epidemiological deterministic delay differential equation model considering a biological controlling approach on mosquitoes, for endemic dengue disease with variable host (human and variable vector (Aedes aegypti populations, and stage structure for mosquitoes. In this model, predator-prey interaction is considered by using larvae as prey and mosquito-fish as predator. We give a complete classification of equilibria of the model, and sufficient conditions for global stability/global attractivity of some equilibria are given by constructing suitable Lyapunov functionals and using Lyapunov-LaSalle invariance principle. Also, numerical simulations are presented to show the validity of our results.

  16. Larvicidal efficacy screening of Anacardaciae crude extracts on the dengue hemorrhagic vector, Aedes aegypti.

    Science.gov (United States)

    Zuharah, W F; Fadzly, N; Ali, Y; Zakaria, R; Juperi, S; Asyraf, M; Dieng, H

    2014-06-01

    Vector-borne diseases are still rife because of the re-emergence of diseases transmitted by mosquitoes. The objective of this paper is to evaluate the larvicidal efficacy of crude leaf extract of Mangifera indica, Gluta renghas, and Melanochyla fasciculiflora against vector of dengue hemorrhagic fever, Aedes aegypti. These plant species are endemic species and widely distributed in Malaysian forests. Leaves of Ma. indica, G. renghas and M. fascculiflora were collected from Teluk Bahang National Park, Penang Malaysia. Fractions of leaves were segregated, air-dried, powdered and extracted using Soxhlet with methanol. The solvent was removed by using rotary evaporator to obtain the crude extract. Using WHO standard larval bioassay test method, third instar larvae of Aedes aegypti were exposed to concentration ranging from 200- 4500 ppm of methanol extract for all plant species. Larval mortality was observed after 24 hours exposure. The highest susceptibility and toxicity was recorded by Mangifera indica with the lowest concentration at 800 ppm followed by M. fasciculiflora and G. renghas. This indicates that crude plant extract is very effective in killing Ae. aegypti mosquitoes. This finding may lead to new low cost alternative, environmentally friendly method for mosquito control programs. To our knowledge, this is the first report on larvicidal bioefficacy from endemic Malaysian plants. PMID:25134898

  17. Comparison of the effect of two excipients (karite nut butter and vaseline on the efficacy of Cocos nucifera, Elaeis guineensis and Carapa procera oil-based repellents formulations against mosquitoes biting in Ivory Coast

    Directory of Open Access Journals (Sweden)

    Konan Y.L.

    2003-06-01

    Full Text Available Repellents in the form of dermal pomades are recommended as a protection against awakening and bedtime mosquito bites. If synthesis repellents are available, they are nevertheless not common and the prices remain out of reach for the communities concerned. The people therefore have to resort more and more to traditional concoctions, some of which have been shown to be effective. After demonstrating that oil-based formulations (lotions, creams, pomades of Cocos nucifera (coconut, Elaeis guineensis (oil palm and Carapa procera (gobi were effective against mosquitoes, it became necessary to study the impact of the two excipients used in their manufacture, on the effectiveness of the repellents. Experiments were carried with Anopheles gambiae and Aedes aegypti under lobaratory conditions and any other mosquitoes collected under field conditions in Ivory Coast. The laboratory results indicate that the average protection times obtained with formulations with karite nut butter as excipient (54.8 ± 37.0 mn and 74.6 ± 26.4 mn respectively on An. gambiae and Ae. aegypti are higher than those recorded with vaseline as excipient (respectively 42.7 ± 30.0 mn and 60.8 ± 33.9 mn. On the other hand, under field conditions, the biting rate percentage reduction obtained with the products with karite nut butter and vaseline excipient were similar (respectively 29.8 % and 35.9 % for all mosquitoes collected and 45.7 % and 47.4 % against An. gambiae. Nevertheless, the use of karite nut butter on repellent products should be encouraged because its sale price is very lower (10 time less than the vaseline's.

  18. Comparison of the effect of two excipients (karite nut butter and vaseline) on the efficacy of Cocos nucifera, Elaeis guineensis and Carapa procera oil-based repellents formulations against mosquitoes biting in Ivory Coast.

    Science.gov (United States)

    Konan, Y L; Sylla, M S; Doannio, J M; Traoré, S

    2003-06-01

    Repellents in the form of dermal pomades are recommended as a protection against awakening and bedtime mosquito bites. If synthesis repellents are available, they are nevertheless not common and the prices remain out of reach for the communities concerned. The people therefore have to resort more and more to traditional concoctions, some of which have been shown to be effective. After demonstrating that oil-based formulations (lotions, creams, pomades) of Cocos nucifera (coconut), Elaeis guineensis (oil palm) and Carapa procera (gobi) were effective against mosquitoes, it became necessary to study the impact of the two excipients used in their manufacture, on the effectiveness of the repellents. Experiments were carried with Anopheles gambiae and Aedes aegypti under lobaratory conditions and any other mosquitoes collected under field conditions in Ivory Coast. The laboratory results indicate that the average protection times obtained with formulations with karite nut butter as excipient (54.8 +/- 37.0 mn and 74.6 +/- 26.4 mn respectively on An. gambiae and Ae. aegypti) are higher than those recorded with vaseline as excipient (respectively 42.7 +/- 30.0 mn and 60.8 +/- 33.9 mn). On the other hand, under field conditions, the biting rate percentage reduction obtained with the products with karite nut butter and vaseline excipient were similar (respectively 29.8% and 35.9% for all mosquitoes collected and 45.7% and 47.4% against An. gambiae). Nevertheless, the use of karite nut butter on repellent products should be encouraged because its sale price is very lower (10 time less) than the vaseline's.

  19. Field trial on a novel control method for the dengue vector, Aedes aegypti by the systematic use of Olyset® Net and pyriproxyfen in Southern Vietnam

    OpenAIRE

    Tsunoda Takashi; Kawada Hitoshi; Huynh Trang TT; Le Luu Loan; Le San Hoang; Tran Huu Ngoc; Vu Huong Thi Que; Le Hieu Minh; Hasebe Futoshi; Tsuzuki Ataru; Takagi Masahiro

    2013-01-01

    Abstract Background Jars, tanks, and drums provide favorable rearing/breeding sites for Aedes aegypti in Vietnam. However, the use of insecticides to control mosquitoes at such breeding sites has not been approved in Vietnam since they are also often sources of drinking water, making larval vector control difficult. Mosquito nets pre-treated with long-lasting insecticide treated nets (LLITNs) form an effective measure for malaria control. We examined changes in the abundance of immature Aedes...

  20. Field trial on a novel control method for the dengue vector, Aedes aegypti by the systematic use of Olyset® Net and pyriproxyfen in Southern Vietnam

    OpenAIRE

    Tsunoda, Takashi; Kawada, Hitoshi; Huynh, Trang TT; Le Luu, Loan; Le, San Hoang; Tran, Huu Ngoc; Vu, Huong Thi Que; Le, Hieu Minh; Hasebe, Futoshi; Tsuzuki, Ataru; Takagi, Masahiro

    2013-01-01

    Background Jars, tanks, and drums provide favorable rearing/breeding sites for Aedes aegypti in Vietnam. However, the use of insecticides to control mosquitoes at such breeding sites has not been approved in Vietnam since they are also often sources of drinking water, making larval vector control difficult. Mosquito nets pre-treated with long-lasting insecticide treated nets (LLITNs) form an effective measure for malaria control. We examined changes in the abundance of immature Aedes aegyp...

  1. Bloodmeal microfilariae density and the uptake and establishment of Wuchereria bancrofti infections in Culex quinquefasciatus and Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Cleide MR Albuquerque

    1999-09-01

    Full Text Available The relationship between ingestion of microfilariae (mf, production of infective larvae (L3 and mf density in human blood has been suggested as an important determinant in the transmission dynamics of lymphatic filariasis. Here we assess the role of these factors in determining the competence of a natural vector Culex quinquefasciatus and a non vector Aedes aegypti to transmit Wuchereria bancrofti. Mosquitoes were infected via a membrane feeding procedure. Both mosquito species ingested more than the expected number of microfilariae (concentrating factor was 1.28 and 1.81 for Cx. quinquefasciatus and Ae. aegypti, respectively but Cx. quinquefasciatus ingested around twice as many mf as Ae. aegypti because its larger blood meal size. Ae. aegypti showed a faster mf migration capacity compared to Cx. quinquefasciatus but did not allow parasite maturation under our experimental conditions. Similar proportions of melanized parasites were observed in Ae. aegypti (2.4% and Cx. quinquefasciatus (2.1%. However, no relationship between rate of infection and melanization was observed. We conclude that in these conditions physiological factors governing parasite development in the thorax may be more important in limiting vectorial competence than the density of mf ingested.

  2. Susceptibility of larvae of Aedes aegypti (Linnaeus (Diptera: Culicidae to entomopathogenic nematode Heterorhabditis bacteriophora (Poinar (Rhabditida: Heterorhabditidae

    Directory of Open Access Journals (Sweden)

    María L. PESCHIUTTA

    2014-01-01

    Full Text Available Aedes aegypti (Linnaeus (Diptera: Culicidae es vector de los agentes etiológicos de la fiebre amarilla y del dengue. Una alternativa al control químico de este vector es el uso de agentes biológicos. Los nematodos entomopatógenos son efectivos en el control de plagas. La infectividad y el ciclo de vida de un aislado argentino de Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae en larvas de A. aegypti se registró por primera vez bajo condiciones de laborato - rio. Para cada unidad experimental, 30 larvas de mosquito de segundo estadio fueron expuestas a 8 dosis del nematodo (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1. Los juveniles infectivos (JIs utilizados fueron multiplicados sobre Galleria mellonella (Lepidoptera: Pyralidae. La continuidad infectiva de los JIs obtenidos de A. aegypti fue probada aplicándolos en una dosis de 100:1 sobre larvas del mosquito . Las tasas de mortalidad fueron de 0% a 84%. El número de nematodos desarrollados dentro de la larva de mosquito, la mortalidad larval y los nuevos JIs se incrementaron con el aumento de la dosis de nematodos. Los resultados indican que H. bacteriophora es capaz de infectar larvas de A. aegypti , se desarrolla y produce nuevos JIs, permitiendo la continuidad de su ciclo de vida.

  3. A virulent Wolbachia infection decreases the viability of the dengue vector Aedes aegypti during periods of embryonic quiescence.

    Directory of Open Access Journals (Sweden)

    Conor J McMeniman

    Full Text Available A new approach for dengue control has been proposed that relies on life-shortening strains of the obligate intracellular bacterium Wolbachia pipientis to modify mosquito population age structure and reduce pathogen transmission. Previously we reported the stable transinfection of the major dengue vector Aedes aegypti with a life-shortening Wolbachia strain (wMelPop-CLA from the vinegar fly Drosophila melanogaster. Here, we report a further characterization of the phenotypic effects of this virulent Wolbachia infection on several life-history traits of Ae. aegypti. Minor costs of wMelPop-CLA infection for pre-imaginal survivorship, development and adult size were found. However, we discovered that the wMelPop-CLA infection dramatically decreased the viability of desiccated Ae. aegypti eggs over time. Similarly, the reproductive fitness of wMelPop-CLA infected Ae. aegypti females declined with age. These results reveal a general pattern associated with wMelPop-CLA induced pathogenesis in this mosquito species, where host fitness costs increase during aging of both immature and adult life-history stages. In addition to influencing the invasion dynamics of this particular Wolbachia strain, we suggest that the negative impact of wMelPop-CLA on embryonic quiescence may have applied utility as a tool to reduce mosquito population size in regions with pronounced dry seasons or in regions that experience cool winters.

  4. Flavivirus susceptibility in Aedes aegypti.

    Science.gov (United States)

    Black, William C; Bennett, Kristine E; Gorrochótegui-Escalante, Norma; Barillas-Mury, Carolina V; Fernández-Salas, Ildefonso; de Lourdes Muñoz, María; Farfán-Alé, José A; Olson, Ken E; Beaty, Barry J

    2002-01-01

    Aedes aegypti is the primary vector of yellow fever (YF) and dengue fever (DF) flaviviruses worldwide. In this review we focus on past and present research on genetic components and environmental factors in Aedes aegypti that appear to control flavivirus transmission. We review genetic relationships among Ae. aegypti populations throughout the world and discuss how variation in vector competence is correlated with overall genetic differences among populations. We describe current research into how genetic and environmental factors jointly affect distribution of vector competence in natural populations. Based on this information, we propose a population genetic model for vector competence and discuss our recent progress in testing this model. We end with a discussion of approaches being taken to identify the genes that may control flavivirus susceptibility in Ae. aegypti. PMID:12234528

  5. Large diurnal temperature fluctuations negatively influence Aedes aegypti (Diptera: Culicidae) life-history traits.

    Science.gov (United States)

    Carrington, Lauren B; Seifert, Stephanie N; Willits, Neil H; Lambrechts, Louis; Scott, Thomas W

    2013-01-01

    Seasonal variation in dengue virus transmission in northwestern Thailand is inversely related to the magnitude of diurnal temperature fluctuations, although mean temperature does not vary significantly across seasons. We tested the hypothesis that diurnal temperature fluctuations negatively influence epidemiologically important life-history traits of the primary dengue vector, Aedes aegypti (L.), compared with a constant 26 degrees C temperature. A large diurnal temperature range (DTR) (approximately equals 18 degrees C daily swing) extended immature development time (>1 d), lowered larval survival (approximately equals 6%), and reduced adult female reproductive output by 25% 14 d after blood feeding, relative to the constant 26 degreesC temperature. A small DTR (approximately equal 8 degrees C daily swing) led to a negligible or slightly positive effect on the life history traits tested. Our results indicate that there is a negative impact of large DTR on mosquito biology and are consistent with the hypothesis that, in at least some locations, large temperature fluctuations contribute to seasonal reduction in dengue virus transmission. PMID:23427651

  6. 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 (paegypti 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 (p<0.05). In 2011, a pilot operational program was evaluated in Kandal Province, a temephos resistant site. It was concluded that 2 cycles of Bti treatment 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. PMID:27627758

  7. Insecticide susceptibility status of Aedes aegypti and Anopheles stephensi larvae against temephos in Delhi, India

    Directory of Open Access Journals (Sweden)

    R.K. Singh

    2014-09-01

    Full Text Available Temephos is used as a larvicide in urban areas in India to control the population of mosquito vectors viz. Anopheles stephensi and Aedes aegypti. The susceptibility status of Ae. aegypti and An. stephensi to temophos in various zones of Municipal Corporation of Delhi was evaluated using the WHO method for determining larval susceptibility test kit. Results revealed that the larval mortality of Ae. aegypti collected from different localities ranged between 64.88% to 98.22%. The highest mortality was recorded from Sangam Vihar (98.22% and lowest was recorded from Majnu ka tila (64.88%. Ae. aegypti larvae collected from Sangam Vihar locality was found fully susceptible to temephos, from two localities viz. Uttam Nagar and Pitampura of study area were tolerant to temephos, and from five localities viz. Majnu ka tila, Shastri Park, Mayur Vihar II, Tilak Bridge and Nagal Dewat showed development of resistance against temephos at diagnostic concentrations. However, larval populations of An. stephensi were fully susceptible to temephos in all the localities. The present study indicates the possible development of resistance against temephos in the larvae of Ae. aegypti in some areas in Delhi.

  8. Heat Sensitivity of wMel Wolbachia during Aedes aegypti Development.

    Directory of Open Access Journals (Sweden)

    Jill N Ulrich

    2016-07-01

    Full Text Available The wMel strain of Wolbachia bacteria is known to prevent dengue and Zika virus transmission in the mosquito vector Aedes aegypti. Accordingly, the release of wMel-infected A. aegypti in endemic regions has been recommended by the World Health Organization as a potential strategy for controlling dengue and Zika outbreaks. However, the utility of this approach could be limited if high temperatures in the aquatic habitats where A. aegypti develop are detrimental to Wolbachia. We exposed wMel-infected A. aegypti eggs and larvae to fluctuating daily temperatures of 30-40°C for three, five, or seven days during their development. We found that Wolbachia levels in females emerging from heat treatments were significantly lower than in the controls that had developed at 20-30°C. Notably, seven days of high temperatures starting at the egg stage reduced Wolbachia levels in emerging females to less than 0.1% of the wMel control levels. However, after adult females returned to 20-30°C for 4-7 days, they experienced differing degrees of Wolbachia recovery. Our findings suggest that the spread of Wolbachia in wild A. aegypti populations and any consequent protection from dengue and Zika viruses might be limited in ecosystems that experience periods of extreme heat, but Wolbachia levels recover partially after temperatures return to normal.

  9. Heat Sensitivity of wMel Wolbachia during Aedes aegypti Development.

    Science.gov (United States)

    Ulrich, Jill N; Beier, John C; Devine, Gregor J; Hugo, Leon E

    2016-07-01

    The wMel strain of Wolbachia bacteria is known to prevent dengue and Zika virus transmission in the mosquito vector Aedes aegypti. Accordingly, the release of wMel-infected A. aegypti in endemic regions has been recommended by the World Health Organization as a potential strategy for controlling dengue and Zika outbreaks. However, the utility of this approach could be limited if high temperatures in the aquatic habitats where A. aegypti develop are detrimental to Wolbachia. We exposed wMel-infected A. aegypti eggs and larvae to fluctuating daily temperatures of 30-40°C for three, five, or seven days during their development. We found that Wolbachia levels in females emerging from heat treatments were significantly lower than in the controls that had developed at 20-30°C. Notably, seven days of high temperatures starting at the egg stage reduced Wolbachia levels in emerging females to less than 0.1% of the wMel control levels. However, after adult females returned to 20-30°C for 4-7 days, they experienced differing degrees of Wolbachia recovery. Our findings suggest that the spread of Wolbachia in wild A. aegypti populations and any consequent protection from dengue and Zika viruses might be limited in ecosystems that experience periods of extreme heat, but Wolbachia levels recover partially after temperatures return to normal.

  10. Heat Sensitivity of wMel Wolbachia during Aedes aegypti Development

    Science.gov (United States)

    Beier, John C.; Devine, Gregor J.; Hugo, Leon E.

    2016-01-01

    The wMel strain of Wolbachia bacteria is known to prevent dengue and Zika virus transmission in the mosquito vector Aedes aegypti. Accordingly, the release of wMel-infected A. aegypti in endemic regions has been recommended by the World Health Organization as a potential strategy for controlling dengue and Zika outbreaks. However, the utility of this approach could be limited if high temperatures in the aquatic habitats where A. aegypti develop are detrimental to Wolbachia. We exposed wMel-infected A. aegypti eggs and larvae to fluctuating daily temperatures of 30–40°C for three, five, or seven days during their development. We found that Wolbachia levels in females emerging from heat treatments were significantly lower than in the controls that had developed at 20–30°C. Notably, seven days of high temperatures starting at the egg stage reduced Wolbachia levels in emerging females to less than 0.1% of the wMel control levels. However, after adult females returned to 20–30°C for 4–7 days, they experienced differing degrees of Wolbachia recovery. Our findings suggest that the spread of Wolbachia in wild A. aegypti populations and any consequent protection from dengue and Zika viruses might be limited in ecosystems that experience periods of extreme heat, but Wolbachia levels recover partially after temperatures return to normal. PMID:27459519

  11. Changing domesticity of Aedes aegypti in northern peninsular Malaysia: reproductive consequences and potential epidemiological implications.

    Directory of Open Access Journals (Sweden)

    Rahman G M Saifur

    Full Text Available BACKGROUND: The domestic dengue vector Aedes aegypti mosquitoes breed in indoor containers. However, in northern peninsular Malaysia, they show equal preference for breeding in both indoor and outdoor habitats. To evaluate the epidemiological implications of this peridomestic adaptation, we examined whether Ae. aegypti exhibits decreased survival, gonotrophic activity, and fecundity due to lack of host availability and the changing breeding behavior. METHODOLOGY/PRINCIPAL FINDINGS: This yearlong field surveillance identified Ae. aegypti breeding in outdoor containers on an enormous scale. Through a sequence of experiments incorporating outdoors and indoors adapting as well as adapted populations, we observed that indoors provided better environment for the survival of Ae. aegypti and the observed death patterns could be explained on the basis of a difference in body size. The duration of gonotrophic period was much shorter in large-bodied females. Fecundity tended to be greater in indoor acclimated females. We also found increased tendency to multiple feeding in outdoors adapted females, which were smaller in size compared to their outdoors breeding counterparts. CONCLUSION/SIGNIFICANCE: The data presented here suggest that acclimatization of Ae. aegypti to the outdoor environment may not decrease its lifespan or gonotrophic activity but rather increase breeding opportunities (increased number of discarded containers outdoors, the rate of larval development, but small body sizes at emergence. Size is likely to be correlated with disease transmission. In general, small size in Aedes females will favor increased blood-feeding frequency resulting in higher population sizes and disease occurrence.

  12. Heat Sensitivity of wMel Wolbachia during Aedes aegypti Development.

    Science.gov (United States)

    Ulrich, Jill N; Beier, John C; Devine, Gregor J; Hugo, Leon E

    2016-07-01

    The wMel strain of Wolbachia bacteria is known to prevent dengue and Zika virus transmission in the mosquito vector Aedes aegypti. Accordingly, the release of wMel-infected A. aegypti in endemic regions has been recommended by the World Health Organization as a potential strategy for controlling dengue and Zika outbreaks. However, the utility of this approach could be limited if high temperatures in the aquatic habitats where A. aegypti develop are detrimental to Wolbachia. We exposed wMel-infected A. aegypti eggs and larvae to fluctuating daily temperatures of 30-40°C for three, five, or seven days during their development. We found that Wolbachia levels in females emerging from heat treatments were significantly lower than in the controls that had developed at 20-30°C. Notably, seven days of high temperatures starting at the egg stage reduced Wolbachia levels in emerging females to less than 0.1% of the wMel control levels. However, after adult females returned to 20-30°C for 4-7 days, they experienced differing degrees of Wolbachia recovery. Our findings suggest that the spread of Wolbachia in wild A. aegypti populations and any consequent protection from dengue and Zika viruses might be limited in ecosystems that experience periods of extreme heat, but Wolbachia levels recover partially after temperatures return to normal. PMID:27459519

  13. Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi(Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

    Objective:To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria(E.coronaria) and Caeslpinia pulckerrima(C.pulcherrima) against Culex quinquefasciatus(Cx.quinquefasciatus),Aedes aegypti(Ae.aegypti) and Anopheles stephensi(An. stephensi).Methods: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 under the laboratory conditions. Results:The crude extract of E.coronaria exerted zero hatchability(100%mortality) at 250.200 and 150 ppm for Cx.quinqitefasciatus,Ae.aegypti and An.stephensi,respectively.The crude extract of C.pulchenima 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.pukherrima 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.Conclusions:From the results it can be concluded the crude extracts of E.coronaria and C.pukherrima are an excellent potential for controlling Cx.quinquefasciatus,Ae.aegypti and An.stephensi mosquitoes.

  14. Electroantennogram, flight orientation and oviposition responses of Anopheles stephensi and Aedes aegypti to a fatty acid ester-propyl octadecanoate.

    Science.gov (United States)

    Seenivasagan, Thangaraj; Sharma, Kavita R; Prakash, Shri

    2012-10-01

    Studies were carried out to evaluate the role of a C(21)-fatty acid ester; propyl octadecanoate (PO) for olfaction-mediated behavioral responses of urban malaria vector, Anopheles stephensi and dengue vector, Aedes aegypti mosquitoes using electroantennogram (EAG), flight orientation and oviposition experiments. Dose dependent electrophysiological responses were recorded for PO from the antenna of both mosquito species in which 10(-5) g elicited significant EAG response. An. stephensi exhibited 2.4, 4.2 and 5.5 fold increased EAG response compared to control, while Ae. aegypti showed 1.9, 4.6 and 5.8 fold EAG responses respectively at 10(-7) g, 10(-6) g and 10(-5) g doses. In the Y-tube olfactometer, 77-80% gravid females of An. stephensi, and 64-77% of Ae. aegypti were caught in the chambers releasing 10(-6) g and 10(-5) g plume of PO. The synthetic fatty acid ester loaded onto an effervescent tablet at 0.1 mg/L, 1 mg/L and 10 mg/L elicited increased ovipositional responses from gravid mosquitoes compared to control. The oviposition activity indices (OAI) of An. stephensi females were +0.40, +0.51 and +0.58, whereas the OAI for Ae. aegypti females were +0.05, +0.36 and +0.57 respectively in 0.1, 1, 10 mg/L of PO; indicated concentration dependent increased egg deposition. Similarly, in the residual activity studies, oviposition substrates treated with PO on effervescent tablet at 1mg/L and 10mg/L received significantly increased egg deposition by gravid females of both mosquito species for up to 1 week compared to control substrates. PO can potentially be used in ovitraps to monitor An. stephensi and Ae. aegypti populations in the vector surveillance programs.

  15. Expression profile of genes during resistance reversal in a temephos selected strain of the dengue vector, Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Clare Strode

    Full Text Available BACKGROUND: The mosquito Aedes aegypti is one of the most important disease vectors because it transmits two major arboviruses, dengue and yellow fever, which cause significant global morbidity and mortality. Chemical insecticides form the cornerstone of vector control. The organophosphate temephos a larvicide recommended by WHO for controlling Ae. aegypti, however, resistance to this compound has been reported in many countries, including Brazil. METHODOLOGY/PRINCIPAL FINDINGS: The aim of this study was to identify genes implicated in metabolic resistance in an Ae. aegypti temephos resistant strain, named RecR, through microarray analysis. We utilized a custom 'Ae. aegypti detox chip' and validated microarray data through RT-PCR comparing susceptible and resistant individuals. In addition, we analyzed gene expression in 4(th instar larvae from a reversed susceptible strain (RecRev, exposed and unexposed to temephos. The results obtained revealed a set of 13 and 6 genes significantly over expressed in resistant adult mosquitoes and larvae, respectively. One of these genes, the cytochrome P450 CYP6N12, was up-regulated in both stages. RT-PCR confirmed the microarray results and, additionally, showed no difference in gene expression between temephos exposed and unexposed RecRev mosquitoes. This suggested that the differences in the transcript profiles among the strains are heritable due to a selection process and are not caused by immediate insecticide exposure. Reversal of temephos resistance was demonstrated and, importantly, there was a positive correlation between a decrease in the resistance ratio and an accompanying decrease in the expression levels of previously over expressed genes. Some of the genes identified here have also been implicated in metabolic resistance in other mosquito species and insecticide resistant populations of Ae. aegypti. CONCLUSIONS/SIGNIFICANCE: The identification of gene expression signatures associated to

  16. Patient-based dengue virus surveillance in Aedes aegypti from Recife, Brazil

    Directory of Open Access Journals (Sweden)

    D.R.D. Guedes

    2010-06-01

    Full Text Available Background & objectives: Dengue is currently one of the most important arthropod-borne diseasesand may be caused by four different dengue virus serotypes (DENV-1 to DENV-4, transmittedmainly by Aedes aegypti (Diptera: Culicidae mosquitoes. With the lack of a dengue vaccine,vector control strategies constitute a crucial mode to prevent or reduce disease transmission. Inthis context, DENV detection in natural Ae. aegypti populations may serve as a potential additionaltool for early prediction systems of dengue outbreaks, leading to an intensification of vector controlmeasures, aimed at reducing disease transmission. In Brazil, this type of surveillance has beenperformed sporadically by a few groups and has not been incorporated as a routine activity incontrol programs. This study aimed at detecting DENV in natural Ae. aegypti from Recife,Pernambuco, to check the circulating serotypes and the occurrence of transovarial transmission inlocal mosquito populations.Methods: From January 2005 to June 2006, mosquitoes (adults and eggs were collected in houseswhere people with clinical suspicion of dengue infection lived at. RNA was extracted from pooledmosquitoes and RT-PCR was performed in these samples for detection of the four DENV serotypes.Results & conclusion: Out of 83 pools of adult mosquitoes collected in the field, nine were positivefor DENV: five for DENV-1, two for DENV-2 and two for DENV-3. From 139 pools of adultmosquitoes reared from collected eggs, there were 17 positive pools: three for DENV-1, 10 forDENV-2, and four for DENV-3. These results are discussed in the paper in regard to the localdengue epidemiological data. The conclusions clearly point to the informative power and sensitivityof DENV entomological surveillance and to the importance of including mosquito immature formsin this strategy.

  17. Physiological and morphological aspects of Aedes aegypti developing larvae: effects of the chitin synthesis inhibitor novaluron.

    Directory of Open Access Journals (Sweden)

    Luana C Farnesi

    Full Text Available Population control of the dengue vector mosquito, Aedes aegypti, is difficult due to many reasons, one being the development of resistance to neurotoxic insecticides employed. The biosynthesis of chitin, a major constituent of insect cuticle, is a novel target for population control. Novaluron is a benzoylphenylurea (BPU that acts as a chitin synthesis inhibitor, already used against mosquitoes. However, information regarding BPU effects on immature mosquito stages and physiological parameters related with mosquito larval development are scarce. A set of physiological parameters were recorded in control developing larvae and novaluron was administered continuously to Ae. aegypti larvae, since early third instar. Larval instar period duration was recorded from third instar until pupation. Chitin content was measured during third and fourth instars. Fourth instars were processed histochemically at the mesothorax region, stained with hematoxylin and eosin (HE for assessment of internal tissues, and labeled with WGA-FITC to reveal chitinized structures. In control larvae: i there is a chitin content increase during both third and fourth instars where late third instars contain more chitin than early fourth instars; ii thoracic organs and a continuous cuticle, closely associated with the underlying epidermis were observed; iii chitin was continuously present throughout integument cuticle. Novaluron treatment inhibited adult emergence, induced immature mortality, altered adult sex ratio and caused delay in larval development. Moreover, novaluron: i significantly affected chitin content during larval development; ii induced a discontinuous and altered cuticle in some regions while epidermis was often thinner or missing; iii rendered chitin cuticle presence discontinuous and less evident. In both control and novaluron larvae, chitin was present in the peritrophic matrix. This study showed quantitatively and qualitatively evidences of novaluron effects

  18. Effect of isodillapiole on the expression of the insecticide resistance genes GSTE7 and CYP6N12 in Aedes aegypti from central Amazonia.

    Science.gov (United States)

    Lima, V S; Pinto, A C; Rafael, M S

    2015-12-11

    The yellow fever mosquito Aedes (Stegomyia) aegypti is the main vector of dengue arbovirus and other arboviruses. Dengue prevention measures for the control of A. aegypti involve mainly the use of synthetic insecticides. The constant use of insecticides has caused resistance in this mosquito. Alternative studies on plant extracts and their products have been conducted with the aim of controlling the spread of the mosquito. Dillapiole is a compound found in essential oils of the plant Piper aduncum (Piperaceae) which has been effective as a biopesticide against A. aegypti. Isodillapiole is a semisynthetic substance obtained by the isomerization of dillapiole. In the present study, isodillapiole was evaluated for its potential to induce differential expression of insecticide resistance genes (GSTE7 and CYP6N12) in 3rd instar larvae of A. aegypti. These larvae were exposed to this compound at two concentrations (20 and 40 μg/mL) for 4 h during four generations (G1, G2, G3, and G4). Quantitative RT-PCR was used to assess the expression of GSTE7 and CYP6N12 genes. GSTE7 and CYP6N12 relative expression levels were higher at 20 than at 40 μg/mL and varied among generations. The decrease in GSTE7 and CYP6N12 expression levels at the highest isodillapiole concentration suggests that larvae may have suffered from metabolic stress, revealing a potential alternative product in the control of A. aegypti.

  19. Efficacy of IGR compound Starycide 480 SC (Triflumuron against mosquito larvae in clear and polluted water

    Directory of Open Access Journals (Sweden)

    C.P. Batra, P.K. Mittal, T. Adak & M.A. Ansari

    2005-09-01

    Full Text Available Background & objectives: An environmental friendly formulation Starycide 480 SC (Triflumuron–OMS-2015 , a new insect growth regulator with chitin synthesis inhibitor type mode of action wasevaluated against mosquito larvae in laboratory and small-scale field trials carried out in and aroundDelhi.Methods: The formulation was tested in laboratory for its bio-efficacy against late III instar mosquitolarvae of different species using WHO bioassay procedure. In the field formulation was sprayed atdoses of 0.3, 0.5 and 1 ppm (g/m3 in the natural breeding habitats of Anopheles and Culex mosquitoes.The impact was assessed by monitoring densities of larvae by dipper and observing the reductionin larval density and inhibition of adult emergence.Results: In the laboratory, formulation was more effective against larvae of Anopheles stephensi andAedes aegypti than Culex quinquefasciatus, but it produced 100% inhibition of adult emergence forall mosquito species at a concentration of 0.02 ppm. In the field trials, formulation did not produce100% reduction in the density of late stage larvae even at 1 ppm (g/m3, the highest dose tested, butit resulted in 100% inhibition of pupal formation of both Anopheles and Culex spp in different typesof habitats for 3–7 weeks even at a lower dose of 0.5 ppm.Interpretation & conclusion : Application of triflumuron in the natural breeding habitats in bothclean and polluted water @ 0.5 ppm (g/m3 resulted in complete inhibition of adult emergence of bothAnopheles and Culex spp for 3–7 weeks. This formulation may be tested in large-scale field trials forfurther use in the vector control programme.

  20. Potency of Pandanus amaryllifolius and Notophanax scutellarium as Aedes albopictus Mosquito Repellent

    Directory of Open Access Journals (Sweden)

    Rina Marina

    2012-12-01

    Full Text Available Aedes aegypti and Ae. albopictus mosquitoes being the vector of Dengue Haemorrhagic Fever (DHF. Various effort have been done to control the mosquitoes, including using plant extract as repellent. Pandanus amaryllifolius and Notophanax scutellarium leaf were known to posses repellent activity for mosquito species. The study aimed to examine efJectiveness of P. amaryllifolius and N. scutellarium leaves as repellent for Ae. albopictus. The result study on 1 hr treatment showed that power protection of pandan leaves (N. scutellarium was 93.55%, while mangkokan leaves (P. amaryllifolius was 87.5%. Based on ANOVA analysis, there was not significantly different of power protection between N. scutellarium leaves and P. amaryllifolius leaves extracts against Ae. albopictus mosquitoes. Both of these test, plants has showed the potential to be a repellent and eliminate the emergence of Ae. albopictus mosquitoes, so it may effectively reduce contact between host and dengue vector.

  1. Diversity and distribution of tree hole mosquitoes in Puducherry Union Territory, India

    Institute of Scientific and Technical Information of China (English)

    Periyasamy Senthamarai Selvan; Arulsamy Jebanesan; Chinnusamy Makesh Kumar

    2015-01-01

    Objective:To study diversity and distribution of tree hole mosquitoes at Puducherry Union Territory. Methods:Random collections were carried out in tree holes at collection sites by using suction tube. Mosquitoes are identified by standard entomological procedures. Results: A total of 235 mosquitoes were collected from tree holes, comprising 3 genera and 12 species. They are,Aedes aegypti, Aedes albopictus, Aedes stokesi, Aedes simpsoni, Anopheles subpictus, Anopheles stephensi, Anopheles culiciformis, Anopheles maculatus, Culex quinquefasciatus, Culex pseudovishnui, Culex tritaeniorhynchus, and Culex decens. The results reveal thatAedes species is the dominant species in tree holes. Simpson’s dominance index and Shanon-Wiener diversity index of 0.182 7 and 0.833 6 were respectively recorded for all tree hole mosquitoes. Conclusions:The diversity studies of tree hole mosquitoes in the study area are necessary for the implementation of appropriate control strategies.

  2. Effect of two commercial herbicides on life history traits of a human disease vector, Aedes aegypti, in the laboratory setting.

    Science.gov (United States)

    Morris, Alexandra; Murrell, Ebony G; Klein, Talan; Noden, Bruce H

    2016-07-01

    Some mosquito species utilize the small niches of water that are abundant in farmland habitats. These niches are susceptible to effects from agricultural pesticides, many of which are applied aerially over large tracts of land. One principal form of weed control in agricultural systems involves the development of herbicide-tolerant crops. The impact of sub-agricultural levels of these herbicides on mosquito survival and life-history traits of resulting adults have not been determined. The aim of this study was to test the effect of two commercial herbicides (Beyond and Roundup) on the survivorship, eclosion time, and body mass of Aedes aegypti. First instar A. aegypti larvae were exposed to varying concentrations (270, 550 and 820 μg/m(2) of glyphosate and 0.74, 1.49, 2.24 μL imazamox/m(2)), all treatments being below recommended application rates, of commercial herbicides in a controlled environment and resulting adult mosquitoes were collected and weighed. Exposure to Roundup had a significant negative effect on A. aegypti survivorship at medium and high sub-agricultural application concentrations, and negatively affected adult eclosion time at the highest concentration. However, exposure to low concentrations of Beyond significantly increased A. aegypti survivorship, although adult female mass was decreased at medium sub-agricultural concentrations. These results demonstrate that low concentrations of two different herbicides, which can occur in rural larval habitats as a result of spray drift, can affect the same species of mosquito in both positive and negative ways depending on the herbicide applied. The effects of commercial herbicides on mosquito populations could have an important effect on disease transmission within agricultural settings, where these and other herbicides are extensively applied to reduce weed growth. PMID:26965703

  3. The Insecticide Susceptibility Status of Aedes aegypti (Diptera: Culicidae) in Farm and Nonfarm Sites of Lagos State, Nigeria.

    Science.gov (United States)

    Ayorinde, A; Oboh, B; Oduola, A; Otubanjo, O

    2015-01-01

    Nigeria is one of the malaria-endemic countries. In Lagos State, Nigeria, various malaria vector control programs including the use of chemical insecticides are currently being implemented. This study was designed to provide information on the susceptibility status of some nontargeted vectors such as Aedes aegypti. Adult Ae. aegypti mosquitoes from two farm sites and a nonfarm site were exposed to World Health Organization test papers impregnated with Deltamethrin (0.05%), Permethrin (0.75%), and DDT (4%) insecticides. The Knockdown time (KdT50 and KdT95) and percentage mortality after 24 h post exposure were determined. In all the exposed mosquito populations to permethrin, mortality rate > 98% (susceptibility) was recorded, whereas mortality rates  98% (susceptibility) to deltamethrin were observed in the nonfarm site and farm sites mosquito populations, respectively. All the mosquito populations were resistant to DDT in 2 yr. The KdT50 of the populations to DDT increased (60.2-69.6) in one of the farm sites and the nonfarm site (68.9-199.96), while a decrease (243-63.4) in another farm site in 2 yr. Significant difference (P aegypti mosquitoes in the second year after exposure to deltamethrin and DDT. An increase in KdT95 after exposure to deltamethrin in the first year was recorded. Higher KdT values and lower mortality rates in Ae. aegypti populations in the nonfarm sites are indications there are existing factors selecting for insecticide resistance outside agricultural use of insecticides.

  4. Development of the gravid Aedes trap for the capture of adult female container-exploiting mosquitoes (Diptera: Culicidae).

    Science.gov (United States)

    Eiras, Alvaro E; Buhagiar, Tamara S; Ritchie, Scott A

    2014-01-01

    Monitoring dengue vector control by sampling adult Aedes aegypti (L.) recently has been used to replace both larval and pupal surveys. We have developed and evaluated the Gravid Aedes Trap (GAT) through a sequential behavioral study. The GAT does not require electricity to function, and trapped mosquitoes are identified easily during trap inspections. The GAT concept relies on visual and olfactory cues to lure gravid Ae. aegypti and an insecticide to kill trapped mosquitoes. Gravid mosquitoes are lured to a black bucket base containing oviposition attractant (infusion) and are trapped in a translucent chamber impregnated with a pyrethroid insecticide where they are killed within 3-15 min. In semifield observations, the GAT captured a significantly higher proportion of gravid mosquitoes than the double sticky ovitrap. We also demonstrated that the visual cues of the prototype GAT-LgBF (large black base bucket with a black funnel at the top of the translucent chamber) captured a significantly higher proportion of gravid mosquitoes than the other prototypes. The visual contrast created by the addition of a white lid to the top of the black funnel significantly increased the number of captured gravid mosquitoes when compared with the GAT-LgBF in semifield trials. We conclude that the GAT is more efficient in recapturing gravid Ae. aegypti when compared with sticky ovitraps. The GAT is an effective, practical, low cost, and easily transportable trap, features that are essential in large-scale monitoring programs, particularly in areas where funding is limited.

  5. Effects of environment, dietary regime and ageing on the dengue vector microbiota: evidence of a core microbiota throughout Aedes aegypti lifespan

    Science.gov (United States)

    David, Mariana Rocha; dos Santos, Lilha Maria Barbosa; Vicente, Ana Carolina Paulo; Maciel-de-Freitas, Rafael

    2016-01-01

    Abstract Mosquito midgut microbiota is a key component of vector competence, as gut bacteria can disturb pathogen development. In this study, we addressed the microbiota composition of Aedes aegypti during its lifespan, under field conditions. We also investigated the possible effects of environment, dietary regime and ageing on the gut community composition. We employed culture independent and dependent approaches to characterise vector microbiota. There was evidence of a lifelong stable core microbiota after mosquitoes were released into an urban settlement, where they presumably fed on a range of vertebrate hosts and carbohydrate sources. This core was formed mainly of bacteria belonging to the genera Pseudomonas, Acinetobacter, Aeromonas and Stenotrophomonas and to the families Oxalobacteraceae, Enterobacteriaceae and Comamonadaceae. We showed that both dietary regime and age were associated with the abundance of some bacterial groups in the Ae. aegypti microbiota. The majority of the bacterial groups we identified have been detected in the midgut of Ae. aegypti from laboratory and wild populations, indicating a possible core microbiota associated with this mosquito species. Our findings suggest that Ae. aegypti harbours a stable bacterial community during its adult life, similar to mosquito populations from distinct geographic areas, which may be further explored for arbovirus biocontrol strategies. PMID:27580348

  6. Effects of environment, dietary regime and ageing on the dengue vector microbiota: evidence of a core microbiota throughout Aedes aegypti lifespan.

    Science.gov (United States)

    David, Mariana Rocha; Santos, Lilha Maria Barbosa Dos; Vicente, Ana Carolina Paulo; Maciel-de-Freitas, Rafael

    2016-09-01

    Mosquito midgut microbiota is a key component of vector competence, as gut bacteria can disturb pathogen development. In this study, we addressed the microbiota composition of Aedes aegypti during its lifespan, under field conditions. We also investigated the possible effects of environment, dietary regime and ageing on the gut community composition. We employed culture independent and dependent approaches to characterise vector microbiota. There was evidence of a lifelong stable core microbiota after mosquitoes were released into an urban settlement, where they presumably fed on a range of vertebrate hosts and carbohydrate sources. This core was formed mainly of bacteria belonging to the genera Pseudomonas, Acinetobacter, Aeromonas and Stenotrophomonas and to the families Oxalobacteraceae, Enterobacteriaceae and Comamonadaceae. We showed that both dietary regime and age were associated with the abundance of some bacterial groups in the Ae. aegypti microbiota. The majority of the bacterial groups we identified have been detected in the midgut of Ae. aegypti from laboratory and wild populations, indicating a possible core microbiota associated with this mosquito species. Our findings suggest that Ae. aegypti harbours a stable bacterial community during its adult life, similar to mosquito populations from distinct geographic areas, which may be further explored for arbovirus biocontrol strategies. PMID:27580348

  7. UV light and urban pollution: Bad cocktail for mosquitoes?

    International Nuclear Information System (INIS)

    Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence i