Sample records for main mosquito vector

  1. Paratransgenesis: a promising new strategy for mosquito vector control.

    PubMed

    Wilke, André Barretto Bruno; Marrelli, Mauro Toledo

    2015-01-01

    The three main mosquito genera, Anopheles, Aedes and Culex, transmit respectively malaria, dengue and lymphatic filariasis. Current mosquito control strategies have proved unsuccessful, and there still is a substantial number of morbidity and mortality from these diseases. Genetic control methods have now arisen as promising alternative strategies, based on two approaches: the replacement of a vector population by disease-refractory mosquitoes and the release of mosquitoes carrying a lethal gene to suppress target populations. However, substantial hurdles and limitations need to be overcome if these methods are to be used successfully, the most significant being that a transgenic mosquito strain is required for every target species, making genetically modified mosquito strategies inviable when there are multiple vector mosquitoes in the same area. Genetically modified bacteria capable of colonizing a wide range of mosquito species may be a solution to this problem and another option for the control of these diseases. In the paratransgenic approach, symbiotic bacteria are genetically modified and reintroduced in mosquitoes, where they express effector molecules. For this approach to be used in practice, however, requires a better understanding of mosquito microbiota and that symbiotic bacteria and effector molecules be identified. Paratransgenesis could prove very useful in mosquito species that are inherently difficult to transform or in sibling species complexes. In this approach, a genetic modified bacteria can act by: (a) causing pathogenic effects in the host; (b) interfering with the host's reproduction; (c) reducing the vector's competence; and (d) interfering with oogenesis and embryogenesis. It is a much more flexible and adaptable approach than the use of genetically modified mosquitoes because effector molecules and symbiotic bacteria can be replaced if they do not achieve the desired result. Paratransgenesis may therefore become an important integrated pest management tool for mosquito control. PMID:26104575

  2. Using Cell Phones for Mosquito Vector Surveillance and Control

    E-print Network

    Bieman, James M.

    and when mosquito control efforts should be focused. Since mosquito immatures (larvae and pupae) developUsing Cell Phones for Mosquito Vector Surveillance and Control S. Lozano-Fuentes, S. Ghosh, J. M--Novel, low-cost approaches to improving prevention and control of vector-borne diseases, such as mosquito

  3. Transcriptome of the adult female malaria mosquito vector Anopheles albimanus

    PubMed Central

    2012-01-01

    Background Human Malaria is transmitted by mosquitoes of the genus Anopheles. Transmission is a complex phenomenon involving biological and environmental factors of humans, parasites and mosquitoes. Among more than 500 anopheline species, only a few species from different branches of the mosquito evolutionary tree transmit malaria, suggesting that their vectorial capacity has evolved independently. Anopheles albimanus (subgenus Nyssorhynchus) is an important malaria vector in the Americas. The divergence time between Anopheles gambiae, the main malaria vector in Africa, and the Neotropical vectors has been estimated to be 100 My. To better understand the biological basis of malaria transmission and to develop novel and effective means of vector control, there is a need to explore the mosquito biology beyond the An. gambiae complex. Results We sequenced the transcriptome of the An. albimanus adult female. By combining Sanger, 454 and Illumina sequences from cDNA libraries derived from the midgut, cuticular fat body, dorsal vessel, salivary gland and whole body, we generated a single, high-quality assembly containing 16,669 transcripts, 92% of which mapped to the An. darlingi genome and covered 90% of the core eukaryotic genome. Bidirectional comparisons between the An. gambiae, An. darlingi and An. albimanus predicted proteomes allowed the identification of 3,772 putative orthologs. More than half of the transcripts had a match to proteins in other insect vectors and had an InterPro annotation. We identified several protein families that may be relevant to the study of Plasmodium-mosquito interaction. An open source transcript annotation browser called GDAV (Genome-Delinked Annotation Viewer) was developed to facilitate public access to the data generated by this and future transcriptome projects. Conclusions We have explored the adult female transcriptome of one important New World malaria vector, An. albimanus. We identified protein-coding transcripts involved in biological processes that may be relevant to the Plasmodium lifecycle and can serve as the starting point for searching targets for novel control strategies. Our data increase the available genomic information regarding An. albimanus several hundred-fold, and will facilitate molecular research in medical entomology, evolutionary biology, genomics and proteomics of anopheline mosquito vectors. The data reported in this manuscript is accessible to the community via the VectorBase website (http://www.vectorbase.org/Other/AdditionalOrganisms/). PMID:22646700

  4. [Omics of vector mosquitoes: a big data platform for vector biology and vector-borne diseases].

    PubMed

    Wu, Yang; Xie, Li-Hua; Liu, Pei-Wen; Li, Xiao-Cong; Yan, Gui-Yun; Chen, Xiao-Guang

    2015-05-20

    Recently the studies on mosquito genomics, transcriptomics and small RNAomics developed rapidly with the novel biotechnologies of the next generation sequencing techniques. The genome sequences of several important vector mosquitoes including Anopheles gambiae, Culex quinquefasciatus, and Aedes aegypti have been published. The genome sizes vary among the different species of mosquitoes and are consistent with the number of the repeat regions. The released genome sequences facilitate gene cloning and identification as for OBP, OR and dsx genes. Transcriptomics provides a useful tool for functional analyses of the mosquito genes, and using this technique, the molecular basis of mosquito blooding, gland proteins and diapauses have been explored. Studies on small RNAomics suggest important roles of miRNAs and piRNAs in ovary development, blood digestion, and immunity against virus infection. The studies on mosquito omics have generated a big data platform for investigation of vector biology and vector-transmitted disease prevention. PMID:26018253

  5. Promoting health education and public awareness about dengue and its mosquito vector in Saudi Arabia.

    PubMed

    Aziz, Al Thabiani; Al-Shami, Salman A; Mahyoub, Jazem A; Hatabbi, Mesed; Ahmad, Abu Hassan; Md Rawi, Che Salmah

    2014-01-01

    Currently, dengue fever is considered as the main health problem in several parts (Mekkah, Jeddah, Jazan and Najran) of Kingdom of Saudi Arabia (KSA) with dramatically increase in the number of cases reported every year. This is associated with obvious ineffectiveness in the recent control and management programs for the mosquito vector (Aedes aegypti). Here, we suggested promoting the health education and public awareness among Saudi people to improve the control of dengue mosquito vector. Several suggestions and recommendations were highlighted here to ensure effectiveness in the future control and management programs of dengue mosquito vector in KSA. PMID:25403705

  6. The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

    PubMed Central

    Smith, Ryan C; Vega-Rodríguez, Joel; Jacobs-Lorena, Marcelo

    2014-01-01

    Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission. PMID:25185005

  7. Ecology of vector mosquitoes in Sri Lanka--suggestions for future mosquito control in rice ecosystems.

    PubMed

    Yasuoka, Junko; Levins, Richard

    2007-07-01

    Mosquito-borne diseases are a major public health threat in Asia. To explore effective mosquito control strategies in rice ecosystems from the ecological point of view, we carried out ecological analyses of vector mosquitoes in Sri Lanka. During the 18-month study period, 14 Anopheles, 11 Culex, 5 Aedes, 2 Mansonia, and 1 Armigeres species were collected, most of which are disease vectors for malaria, filariasis, Japanese encephalitis, or dengue in Sri Lanka and elsewhere in Asia. The density and occurrence of Anopheles and Culex species were the highest in seepage pools and paddy fields, where the majority of niche overlaps between larval mosquito and aquatic insect species were observed. All 7 aquatic insect species, which are larval mosquito predators, overlapped their niche with both Anopheles and Culex larvae. This suggests that conserving these aquatic insect species could be effective in controlling mosquito vectors in the study site. Correlations between several climatic factors and mosquito density were also analyzed, and weather conditions, including higher temperature, lower relative humidity, and higher wind velocity, were found to affect mosquito oviposition, propagation, and survival. These findings deepen our understanding of mosquito ecology and will strengthen future mosquito control strategies in rice ecosystems in Asia. PMID:17883002

  8. [Mosquitoes as vectors for exotic pathogens in Germany].

    PubMed

    Becker, N; Krüger, A; Kuhn, C; Plenge-Bönig, A; Thomas, S M; Schmidt-Chanasit, J; Tannich, E

    2014-05-01

    As a result of intensified globalization of international trade and of substantial travel activities, mosquito-borne exotic pathogens are becoming an increasing threat for Europe. In Germany some 50 different mosquito species are known, several of which have vector competence for pathogens. During the last few years a number of zoonotic arboviruses that are pathogenic for humans have been isolated from mosquitoes in Germany including Usutu, Sindbis and Batai viruses. In addition, filarial worms, such as Dirofilaria repens have been repeatedly detected in mosquitoes from the federal state of Brandenburg. Other pathogens, in particular West Nile virus, are expected to emerge sooner or later in Germany as the virus is already circulating in neighboring countries, e.g. France, Austria and the Czech Republic. In upcoming years the risk for arbovirus transmission might increase in Germany due to increased occurrence of new so-called "invasive" mosquito species, such as the Asian bush mosquito Ochlerotatus japonicus or the Asian tiger mosquito Aedes albopictus. These invasive species are characterized by high vector competence for a broad range of pathogens and a preference for human blood meals. For risk assessment, a number of mosquito and pathogen surveillance projects have been initiated in Germany during the last few years; however, mosquito control strategies and plans of action have to be developed and put into place to allow early and efficient action against possible vector-borne epidemics. PMID:24781910

  9. Harnessing mosquito-Wolbachia symbiosis for vector and disease control.

    PubMed

    Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Hervé C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L

    2014-04-01

    Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs. PMID:24252486

  10. Adult vector control, mosquito ecology and malaria transmission

    PubMed Central

    Brady, Oliver J.; Godfray, H. Charles J.; Tatem, Andrew J.; Gething, Peter W.; Cohen, Justin M.; McKenzie, F. Ellis; Alex Perkins, T.; Reiner, Robert C.; Tusting, Lucy S.; Scott, Thomas W.; Lindsay, Steven W.; Hay, Simon I.; Smith, David L.

    2015-01-01

    Background Standard advice regarding vector control is to prefer interventions that reduce the lifespan of adult mosquitoes. The basis for this advice is a decades-old sensitivity analysis of ‘vectorial capacity’, a concept relevant for most malaria transmission models and based solely on adult mosquito population dynamics. Recent advances in micro-simulation models offer an opportunity to expand the theory of vectorial capacity to include both adult and juvenile mosquito stages in the model. Methods In this study we revisit arguments about transmission and its sensitivity to mosquito bionomic parameters using an elasticity analysis of developed formulations of vectorial capacity. Results We show that reducing adult survival has effects on both adult and juvenile population size, which are significant for transmission and not accounted for in traditional formulations of vectorial capacity. The elasticity of these effects is dependent on various mosquito population parameters, which we explore. Overall, control is most sensitive to methods that affect adult mosquito mortality rates, followed by blood feeding frequency, human blood feeding habit, and lastly, to adult mosquito population density. Conclusions These results emphasise more strongly than ever the sensitivity of transmission to adult mosquito mortality, but also suggest the high potential of combinations of interventions including larval source management. This must be done with caution, however, as policy requires a more careful consideration of costs, operational difficulties and policy goals in relation to baseline transmission. PMID:25733562

  11. Mosquito surveillance in northwestern Italy to monitor the occurrence of tropical vector-borne diseases.

    PubMed

    Pautasso, A; Desiato, R; Bertolini, S; Vitale, N; Radaelli, M C; Mancini, M; Rizzo, F; Mosca, A; Calzolari, M; Prearo, M; Mandola, M L; Maurella, C; Mignone, W; Chiavacci, L; Casalone, C

    2013-11-01

    Mosquito-borne arboviruses (MBV) represent an important health problem, causing diseases and deaths both in human and animals mainly in tropical and subtropical countries. In recent years, they have emerged also in temperate regions where they have caused epidemics. Of mounting concern among public health authorities in Europe are zoonotic mosquito-borne viruses belonging to the Flavivirus genus. The aim of this study was to carry out active surveillance on mosquitoes in two regions of northwestern Italy (Liguria and Piedmont) to gain a better knowledge of the mosquito populations by identifying potential vectors of arboviruses and to investigate arbovirus infection. A network of 61 CO? CDC traps was placed in the study area; sampling was conducted from May to October 2011. A total of 46,677 mosquitoes was collected, identified to species level, and classified according to their vector competence. Mosquitoes collected from 16 traps, selected according to risk-based factors, were tested by biomolecular analysis to detect flavivirus infection. This study highlights the importance of entomological surveillance in northwestern Italy because most of the mosquitoes collected were found to have high vector competence. Moreover, the risk-based virological surveillance allowed to detect the presence of mosquito flavivirus RNA, phylogenetically closely related to the MMV Spanish isolate, in three pools and USUV RNA in one pool in new areas where it has not been reported previously. The availability of continuous data on mosquito populations provides invaluable information for use in cases of an epidemic emergency. Maintenance of this integrated system for the next years will provide stronger data that can inform the design of a risk-based surveillance for the early detection of the occurrence of outbreaks of tropical MBDs. PMID:24589116

  12. Identification of Wolbachia Strains in Mosquito Disease Vectors

    PubMed Central

    Osei-Poku, Jewelna; Han, Calvin; Mbogo, Charles M.; Jiggins, Francis M.

    2012-01-01

    Wolbachia bacteria are common endosymbionts of insects, and some strains are known to protect their hosts against RNA viruses and other parasites. This has led to the suggestion that releasing Wolbachia-infected mosquitoes could prevent the transmission of arboviruses and other human parasites. We have identified Wolbachia in Kenyan populations of the yellow fever vector Aedes bromeliae and its relative Aedes metallicus, and in Mansonia uniformis and Mansonia africana, which are vectors of lymphatic filariasis. These Wolbachia strains cluster together on the bacterial phylogeny, and belong to bacterial clades that have recombined with other unrelated strains. These new Wolbachia strains may be affecting disease transmission rates of infected mosquito species, and could be transferred into other mosquito vectors as part of control programs. PMID:23185484

  13. Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes.

    PubMed

    Neafsey, Daniel E; Waterhouse, Robert M; Abai, Mohammad R; Aganezov, Sergey S; Alekseyev, Max A; Allen, James E; Amon, James; Arcà, Bruno; Arensburger, Peter; Artemov, Gleb; Assour, Lauren A; Basseri, Hamidreza; Berlin, Aaron; Birren, Bruce W; Blandin, Stephanie A; Brockman, Andrew I; Burkot, Thomas R; Burt, Austin; Chan, Clara S; Chauve, Cedric; Chiu, Joanna C; Christensen, Mikkel; Costantini, Carlo; Davidson, Victoria L M; Deligianni, Elena; Dottorini, Tania; Dritsou, Vicky; Gabriel, Stacey B; Guelbeogo, Wamdaogo M; Hall, Andrew B; Han, Mira V; Hlaing, Thaung; Hughes, Daniel S T; Jenkins, Adam M; Jiang, Xiaofang; Jungreis, Irwin; Kakani, Evdoxia G; Kamali, Maryam; Kemppainen, Petri; Kennedy, Ryan C; Kirmitzoglou, Ioannis K; Koekemoer, Lizette L; Laban, Njoroge; Langridge, Nicholas; Lawniczak, Mara K N; Lirakis, Manolis; Lobo, Neil F; Lowy, Ernesto; MacCallum, Robert M; Mao, Chunhong; Maslen, Gareth; Mbogo, Charles; McCarthy, Jenny; Michel, Kristin; Mitchell, Sara N; Moore, Wendy; Murphy, Katherine A; Naumenko, Anastasia N; Nolan, Tony; Novoa, Eva M; O'Loughlin, Samantha; Oringanje, Chioma; Oshaghi, Mohammad A; Pakpour, Nazzy; Papathanos, Philippos A; Peery, Ashley N; Povelones, Michael; Prakash, Anil; Price, David P; Rajaraman, Ashok; Reimer, Lisa J; Rinker, David C; Rokas, Antonis; Russell, Tanya L; Sagnon, N'Fale; Sharakhova, Maria V; Shea, Terrance; Simão, Felipe A; Simard, Frederic; Slotman, Michel A; Somboon, Pradya; Stegniy, Vladimir; Struchiner, Claudio J; Thomas, Gregg W C; Tojo, Marta; Topalis, Pantelis; Tubio, José M C; Unger, Maria F; Vontas, John; Walton, Catherine; Wilding, Craig S; Willis, Judith H; Wu, Yi-Chieh; Yan, Guiyun; Zdobnov, Evgeny M; Zhou, Xiaofan; Catteruccia, Flaminia; Christophides, George K; Collins, Frank H; Cornman, Robert S; Crisanti, Andrea; Donnelly, Martin J; Emrich, Scott J; Fontaine, Michael C; Gelbart, William; Hahn, Matthew W; Hansen, Immo A; Howell, Paul I; Kafatos, Fotis C; Kellis, Manolis; Lawson, Daniel; Louis, Christos; Luckhart, Shirley; Muskavitch, Marc A T; Ribeiro, José M; Riehle, Michael A; Sharakhov, Igor V; Tu, Zhijian; Zwiebel, Laurence J; Besansky, Nora J

    2015-01-01

    Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts. PMID:25554792

  14. Quantifying the mosquito’s sweet tooth: modelling the effectiveness of attractive toxic sugar baits (ATSB) for malaria vector control

    PubMed Central

    2013-01-01

    Background Current vector control strategies focus largely on indoor measures, such as long-lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS); however mosquitoes frequently feed on sugar sources outdoors, inviting the possibility of novel control strategies. Attractive toxic sugar baits (ATSB), either sprayed on vegetation or provided in outdoor bait stations, have been shown to significantly reduce mosquito densities in these settings. Methods Simple models of mosquito sugar-feeding behaviour were fitted to data from an ATSB field trial in Mali and used to estimate sugar-feeding rates and the potential of ATSB to control mosquito populations. The model and fitted parameters were then incorporated into a larger integrated vector management (IVM) model to assess the potential contribution of ATSB to future IVM programmes. Results In the Mali experimental setting, the model suggests that about half of female mosquitoes fed on ATSB solution per day, dying within several hours of ingesting the toxin. Using a model incorporating the number of gonotrophic cycles completed by female mosquitoes, a higher sugar-feeding rate was estimated for younger mosquitoes than for older mosquitoes. Extending this model to incorporate other vector control interventions suggests that an IVM programme based on both ATSB and LLINs may substantially reduce mosquito density and survival rates in this setting, thereby substantially reducing parasite transmission. This is predicted to exceed the impact of LLINs in combination with IRS provided ATSB feeding rates are 50% or more of Mali experimental levels. In addition, ATSB is predicted to be particularly effective against Anopheles arabiensis, which is relatively exophilic and therefore less affected by IRS and LLINs. Conclusions These results suggest that high coverage with a combination of LLINs and ATSB could result in substantial reductions in malaria transmission in this setting. Further field studies of ATSB in other settings are needed to assess the potential of ATSB as a component in future IVM malaria control strategies. PMID:23968494

  15. Monitoring of larval habitats and mosquito densities in the Sudan savanna of Mali: implications for malaria vector control.

    PubMed

    Sogoba, Nafomon; Doumbia, Seydou; Vounatsou, Penelope; Baber, Ibrahima; Keita, Moussa; Maiga, Mamoudou; Traoré, Sékou F; Touré, Abdoulaye; Dolo, Guimogo; Smith, Thomas; Ribeiro, José M C

    2007-07-01

    In Mali, anopheline mosquito populations increase sharply during the rainy season, but are barely detectable in the dry season. This study attempted to identify the dry season mosquito breeding population in and near the village of Bancoumana, Mali, and in a fishing hamlet 5 km from this village and adjacent to the Niger River. In Bancoumana, most larval habitats were human made, and dried out in January-February. In contrast, in the fishing hamlet, productive larval habitats were numerous and found mainly during the dry season (January-May) as the natural result of drying riverbeds. Adult mosquitoes were abundant during the dry season in the fishermen hamlet and rare in Bancoumana. To the extent that the fishermen hamlet mosquito population seeds Bancoumana with the advent of the rainy season, vector control in this small hamlet may be a cost-effective way to ameliorate malaria transmission in the 40-times larger village. PMID:17620634

  16. Odorant receptor-mediated sperm activation in disease vector mosquitoes

    PubMed Central

    Pitts, R. Jason; Liu, Chao; Zhou, Xiaofan; Malpartida, Juan C.; Zwiebel, Laurence J.

    2014-01-01

    Insects, such as the malaria vector mosquito, Anopheles gambiae, depend upon chemoreceptors to respond to volatiles emitted from a range of environmental sources, most notably blood meal hosts and oviposition sites. A subset of peripheral signaling pathways involved in these insect chemosensory-dependent behaviors requires the activity of heteromeric odorant receptor (OR) ion channel complexes and ligands for numerous A. gambiae ORs (AgOrs) have been identified. Although AgOrs are expressed in nonhead appendages, studies characterizing potential AgOr function in nonolfactory tissues have not been conducted. In the present study, we explore the possibility that AgOrs mediate responses of spermatozoa to endogenous signaling molecules in A. gambiae. In addition to finding AgOr transcript expression in testes, we show that the OR coreceptor, AgOrco, is localized to the flagella of A. gambiae spermatozoa where Orco-specific agonists, antagonists, and other odorant ligands robustly activate flagella beating in an Orco-dependent process. We also demonstrate Orco expression and Orco-mediated activation of spermatozoa in the yellow fever mosquito, Aedes aegypti. Moreover, we find Orco localization in testes across distinct insect taxa and posit that OR-mediated responses in spermatozoa may represent a general characteristic of insect reproduction and an example of convergent evolution. PMID:24550284

  17. Vector competence of Aedes aegypti mosquitoes for filarial nematodes is affected by age and nutrient limitation.

    PubMed

    Ariani, Cristina V; Juneja, Punita; Smith, Sophia; Tinsley, Matthew C; Jiggins, Francis M

    2015-01-01

    Mosquitoes are one of the most important vectors of human disease. The ability of mosquitoes to transmit disease is dependent on the age structure of the population, as mosquitoes must survive long enough for the parasites to complete their development and infect another human. Age could have additional effects due to mortality rates and vector competence changing as mosquitoes senesce, but these are comparatively poorly understood. We have investigated these factors using the mosquito Aedes aegypti and the filarial nematode Brugia malayi. Rather than observing any effects of immune senescence, we found that older mosquitoes were more resistant, but this only occurred if they had previously been maintained on a nutrient-poor diet of fructose. Constant blood feeding reversed this decline in vector competence, meaning that the number of parasites remained relatively unchanged as mosquitoes aged. Old females that had been maintained on fructose also experienced a sharp spike in mortality after an infected blood meal ("refeeding syndrome") and few survived long enough for the parasite to develop. Again, this effect was prevented by frequent blood meals. Our results indicate that old mosquitoes may be inefficient vectors due to low vector competence and high mortality, but that frequent blood meals can prevent these effects of age. PMID:25446985

  18. Distribution of Brugia malayi larvae and DNA in vector and non-vector mosquitoes: implications for molecular diagnostics

    PubMed Central

    2009-01-01

    Background The purpose of this study was to extend prior studies of molecular detection of Brugia malayi DNA in vector (Aedes aegypti- Liverpool) and non-vector (Culex pipiens) mosquitoes at different times after ingestion of infected blood. Results Parasite DNA was detected over a two week time course in 96% of pooled thoraces of vector mosquitoes. In contrast, parasite DNA was detected in only 24% of thorax pools from non-vectors; parasite DNA was detected in 56% of midgut pools and 47% of abdomen pools from non-vectors. Parasite DNA was detected in vectors in the head immediately after the blood meal and after 14 days. Parasite DNA was also detected in feces and excreta of the vector and non-vector mosquitoes which could potentially confound results obtained with field samples. However, co-housing experiments failed to demonstrate transfer of parasite DNA from infected to non-infected mosquitoes. Parasites were also visualized in mosquito tissues by immunohistololgy using an antibody to the recombinant filarial antigen Bm14. Parasite larvae were detected consistently after mf ingestion in Ae. aegypti- Liverpool. Infectious L3s were seen in the head, thorax and abdomen of vector mosquitoes 14 days after Mf ingestion. In contrast, parasites were only detected by histology shortly after the blood meal in Cx. pipiens, and these were not labeled by the antibody. Conclusion This study provides new information on the distribution of filarial parasites and parasite DNA in vector and non-vector mosquitoes. This information should be useful for those involved in designing and interpreting molecular xenomonitoring studies. PMID:19922607

  19. Monitoring malaria vector control interventions: effectiveness of five different adult mosquito sampling methods.

    PubMed

    Onyango, Shirley A; Kitron, Uriel; Mungai, Peter; Muchiri, Eric M; Kokwaro, Elizabeth; King, Charles H; Mutuku, Francis M

    2013-09-01

    Long-term success of ongoing malaria control efforts based on mosquito bed nets (long-lasting insecticidal net) and indoor residual spraying is dependent on continuous monitoring of mosquito vectors, and thus on effective mosquito sampling tools. The objective of our study was to identify the most efficient mosquito sampling tool(s) for routine vector surveillance for malaria and lymphatic filariasis transmission in coastal Kenya. We evaluated relative efficacy of five collection methods--light traps associated with a person sleeping under a net, pyrethrum spray catches, Prokopack aspirator, clay pots, and urine-baited traps--in four villages representing three ecological settings along the south coast of Kenya. Of the five methods, light traps were the most efficient for collecting female Anopheles gambiae s.l. (Giles) (Diptera: Culicidae) and Anopheles funestus (Giles) (Diptera: Culicidae) mosquitoes, whereas the Prokopack aspirator was most efficient in collecting Culex quinquefasciatus (Say) (Diptera: Culicidae) and other culicines. With the low vector densities here, and across much of sub-Saharan Africa, wherever malaria interventions, long-lasting insecticidal nets, and/or indoor residual spraying are in place, the use of a single mosquito collection method will not be sufficient to achieve a representative sample of mosquito population structure. Light traps will remain a relevant tool for host-seeking mosquitoes, especially in the absence of human landing catches. For a fair representation of the indoor mosquito population, light traps will have to be supplemented with aspirator use, which has potential for routine monitoring of indoor resting mosquitoes, and can substitute the more labor-intensive and intrusive pyrethrum spray catches. There are still no sufficiently efficient mosquito collection methods for sampling outdoor mosquitoes, particularly those that are bloodfed. PMID:24180120

  20. Monitoring Malaria Vector Control Interventions: Effectiveness of Five Different Adult Mosquito Sampling Methods

    PubMed Central

    Onyango, Shirley A.; Kitron, Uriel; Mungai, Peter; Muchiri, Eric M.; Kokwaro, Elizabeth; King, Charles H.; Mutuku, Francis M.

    2014-01-01

    Long-term success of ongoing malaria control efforts based on mosquito bed nets (long-lasting insecticidal net) and indoor residual spraying is dependent on continuous monitoring of mosquito vectors, and thus on effective mosquito sampling tools. The objective of our study was to identify the most efficient mosquito sampling tool(s) for routine vector surveillance for malaria and lymphatic filariasis transmission in coastal Kenya. We evaluated relative efficacy of five collection methods—light traps associated with a person sleeping under a net, pyrethrum spray catches, Prokopack aspirator, clay pots, and urine-baited traps—in four villages representing three ecological settings along the south coast of Kenya. Of the five methods, light traps were the most efficient for collecting female Anopheles gambiae s.l. (Giles) (Diptera: Culicidae) and Anopheles funestus (Giles) (Diptera: Culicidae) mosquitoes, whereas the Prokopack aspirator was most efficient in collecting Culex quinquefasciatus (Say) (Diptera: Culicidae) and other culicines. With the low vector densities here, and across much of sub-Saharan Africa, wherever malaria interventions, long-lasting insecticidal nets, and/or indoor residual spraying are in place, the use of a single mosquito collection method will not be sufficient to achieve a representative sample of mosquito population structure. Light traps will remain a relevant tool for host-seeking mosquitoes, especially in the absence of human landing catches. For a fair representation of the indoor mosquito population, light traps will have to be supplemented with aspirator use, which has potential for routine monitoring of indoor resting mosquitoes, and can substitute the more labor-intensive and intrusive pyrethrum spray catches. There are still no sufficiently efficient mosquito collection methods for sampling outdoor mosquitoes, particularly those that are bloodfed. PMID:24180120

  1. Landscape Ecology of Sylvatic Chikungunya Virus and Mosquito Vectors in Southeastern Senegal

    PubMed Central

    Diallo, Diawo; Sall, Amadou A.; Buenemann, Michaela; Chen, Rubing; Faye, Oumar; Diagne, Cheikh T.; Faye, Ousmane; Ba, Yamar; Dia, Ibrahima; Watts, Douglas; Weaver, Scott C.; Hanley, Kathryn A.; Diallo, Mawlouth

    2012-01-01

    The risk of human infection with sylvatic chikungunya (CHIKV) virus was assessed in a focus of sylvatic arbovirus circulation in Senegal by investigating distribution and abundance of anthropophilic Aedes mosquitoes, as well as the abundance and distribution of CHIKV in these mosquitoes. A 1650 km2 area was classified into five land cover classes: forest, barren, savanna, agriculture and village. A total of 39,799 mosquitoes was sampled from all classes using human landing collections between June 2009 and January 2010. Mosquito diversity was extremely high, and overall vector abundance peaked at the start of the rainy season. CHIKV was detected in 42 mosquito pools. Our data suggest that Aedes furcifer, which occurred abundantly in all land cover classes and landed frequently on humans in villages outside of houses, is probably the major bridge vector responsible for the spillover of sylvatic CHIKV to humans. PMID:22720097

  2. Mosquito genomics. Extensive introgression in a malaria vector species complex revealed by phylogenomics.

    PubMed

    Fontaine, Michael C; Pease, James B; Steele, Aaron; Waterhouse, Robert M; Neafsey, Daniel E; Sharakhov, Igor V; Jiang, Xiaofang; Hall, Andrew B; Catteruccia, Flaminia; Kakani, Evdoxia; Mitchell, Sara N; Wu, Yi-Chieh; Smith, Hilary A; Love, R Rebecca; Lawniczak, Mara K; Slotman, Michel A; Emrich, Scott J; Hahn, Matthew W; Besansky, Nora J

    2015-01-01

    Introgressive hybridization is now recognized as a widespread phenomenon, but its role in evolution remains contested. Here, we use newly available reference genome assemblies to investigate phylogenetic relationships and introgression in a medically important group of Afrotropical mosquito sibling species. We have identified the correct species branching order to resolve a contentious phylogeny and show that lineages leading to the principal vectors of human malaria were among the first to split. Pervasive autosomal introgression between these malaria vectors means that only a small fraction of the genome, mainly on the X chromosome, has not crossed species boundaries. Our results suggest that traits enhancing vectorial capacity may be gained through interspecific gene flow, including between nonsister species. PMID:25431491

  3. Rapid selection against arbovirus-induced apoptosis during infection of a mosquito vector.

    PubMed

    O'Neill, Katelyn; Olson, Bradley J S C; Huang, Ning; Unis, Dave; Clem, Rollie J

    2015-03-10

    Millions of people are infected each year by arboviruses (arthropod-borne viruses) such as chikungunya, dengue, and West Nile viruses, yet for reasons that are largely unknown, only a relatively small number of mosquito species are able to transmit arboviruses. Understanding the complex factors that determine vector competence could facilitate strategies for controlling arbovirus infections. Apoptosis is a potential antiviral defense response that has been shown to be important in other virus-host systems. However, apoptosis is rarely seen in arbovirus-infected mosquito cells, raising questions about its importance as an antiviral defense in mosquitoes. We tested the effect of stimulating apoptosis during arbovirus infection by infecting Aedes aegypti mosquitoes with a Sindbis virus (SINV) clone called MRE/Rpr, in which the MRE-16 strain of SINV was engineered to express the proapoptotic gene reaper from Drosophila. MRE/Rpr exhibited an impaired infection phenotype that included delayed midgut infection, delayed virus replication, and reduced virus accumulation in saliva. Nucleotide sequencing of the reaper insert in virus populations isolated from individual mosquitoes revealed evidence of rapid and strong selection against maintenance of Reaper expression in MRE/Rpr-infected mosquitoes. The impaired phenotype of MRE/Rpr, coupled with the observed negative selection against Reaper expression, indicates that apoptosis is a powerful defense against arbovirus infection in mosquitoes and suggests that arboviruses have evolved mechanisms to avoid stimulating apoptosis in mosquitoes that serve as vectors. PMID:25713358

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

    Microsoft Academic Search

    Mariangela Bonizzoni; W Augustine Dunn; Corey L Campbell; Ken E Olson; Michelle T Dimon; Osvaldo Marinotti; Anthony A James

    2011-01-01

    BACKGROUND: Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito Aedes aegypti (Diptera, Culicidae), a vector of Dengue

  5. Interplay between Plasmodium infection and resistance to insecticides in vector mosquitoes.

    PubMed

    Alout, Haoues; Yameogo, Bienvenue; Djogbénou, Luc Salako; Chandre, Fabrice; Dabiré, Roch Kounbobr; Corbel, Vincent; Cohuet, Anna

    2014-11-01

    Despite its epidemiological importance, the impact of insecticide resistance on vector-parasite interactions and malaria transmission is poorly understood. Here, we explored the impact of Plasmodium infection on the level of insecticide resistance to dichlorodiphenyltrichloroethane (DDT) in field-caught Anopheles gambiae sensu stricto homozygous for the kdr mutation. Results showed that kdr homozygous mosquitoes that fed on infectious blood were more susceptible to DDT than mosquitoes that fed on noninfectious blood during both ookinete development (day 1 after the blood meal) and oocyst maturation (day 7 after the blood meal) but not during sporozoite invasion of the salivary glands. Plasmodium falciparum infection seemed to impose a fitness cost on mosquitoes by reducing the ability of kdr homozygous A. gambiae sensu stricto to survive exposure to DDT. These results suggest an interaction between Plasmodium infection and the insecticide susceptibility of mosquitoes carrying insecticide-resistant alleles. We discuss this finding in relation to vector control efficacy. PMID:24829465

  6. Efficacy of mosquito traps for collecting potential West Nile mosquito vectors in a natural Mediterranean wetland.

    PubMed

    Roiz, David; Roussel, Marion; Muñoz, Joaquin; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

    2012-04-01

    Surveillance, research, and control of mosquito-borne diseases such as West Nile virus require efficient methods for sampling mosquitoes. We compared the efficacy of BG-Sentinel and Centers for Disease Control and Prevention (CDC)-CO(2) traps in terms of the abundances of host-seeking and blood-fed female mosquitoes and the origin of mosquito bloodmeals. Our results indicate that BG-Sentinel traps that use CO(2) and attractants are as effective as CDC-CO(2) traps for Culex mosquito species, Ochlerotatus caspius, and they are also highly efficient at capturing Anopheles atroparvus host-seeking and blood-fed females with or without CO(2). The CDC-CO(2) trap is the least efficient method for capturing blood-fed females. BG-Sentinel traps with attractants and CO(2) were significantly better at capturing mosquitoes that had fed on mammals than the unbaited BG-Sentinel and CDC-CO(2) traps in the cases of An. atroparvus and Cx. theileri. These results may help researchers to optimize trapping methods by obtaining greater sample sizes and saving time and money. PMID:22492149

  7. Genetic specificity and potential for local adaptation between dengue viruses and mosquito vectors

    PubMed Central

    Lambrechts, Louis; Chevillon, Christine; Albright, Rebecca G; Thaisomboonsuk, Butsaya; Richardson, Jason H; Jarman, Richard G; Scott, Thomas W

    2009-01-01

    Background Several observations support the hypothesis that vector-driven selection plays an important role in shaping dengue virus (DENV) genetic diversity. Clustering of DENV genetic diversity at a particular location may reflect underlying genetic structure of vector populations, which combined with specific vector genotype × virus genotype (G × G) interactions may promote adaptation of viral lineages to local mosquito vector genotypes. Although spatial structure of vector polymorphism at neutral genetic loci is well-documented, existence of G × G interactions between mosquito and virus genotypes has not been formally demonstrated in natural populations. Here we measure G × G interactions in a system representative of a natural situation in Thailand by challenging three isofemale families from field-derived Aedes aegypti with three contemporaneous low-passage isolates of DENV-1. Results Among indices of vector competence examined, the proportion of mosquitoes with a midgut infection, viral RNA concentration in the body, and quantity of virus disseminated to the head/legs (but not the proportion of infected mosquitoes with a disseminated infection) strongly depended on the specific combinations of isofemale families and viral isolates, demonstrating significant G × G interactions. Conclusion Evidence for genetic specificity of interactions in our simple experimental design indicates that vector competence of Ae. aegypti for DENV is likely governed to a large extent by G × G interactions in genetically diverse, natural populations. This result challenges the general relevance of conclusions from laboratory systems that consist of a single combination of mosquito and DENV genotypes. Combined with earlier evidence for fine-scale genetic structure of natural Ae. aegypti populations, our finding indicates that the necessary conditions for local DENV adaptation to mosquito vectors are met. PMID:19589156

  8. Vector mosquitoes of Wuchereria bancrofti at Bicol region in the Philippines. 1. Transmission capability.

    PubMed

    Suguri, S; Cabrera, B D; Shibuya, T; Harada, M; Valeza, F S; Nagata, T; Tanaka, H; Ishii, A; Go, T G

    1985-04-01

    Mosquitoes were surveyed for the capability of filaria transmission at Sitio Bacolod and Barrio Salvacion, in Bicol region, Luzon, Philippines. The results of indoor collections and experimental infections showed that the infective rates and the median density of infective larvae per infected mosquito were significantly higher in Aedes poicilius than in Culex quinquefasciatus. Aedes poicilius was found to be the principal vector of bancroftian filariasis in this region. PMID:3900489

  9. Peptide Sequence of an Antibiotic Cecropin from the Vector Mosquito, Aedes albopictus

    Microsoft Academic Search

    Dongxu Sun; Eric D. Eccleston; Ann M. Fallon

    1998-01-01

    We have identified a 35-amino acid antibiotic cecropin secreted by an established mosquito cell line. C7-10 cells from the vector mosquito,Aedes albopictus,were incubated with heat-killedEscherichia coli,and materials secreted into the cell culture supernatant were recovered by acid precipitation. Following batch elution from Sep-Pak C18 cartridges and further purification by reverse phase high performance liquid chromatography (RP-HPLC) a predominant peak of

  10. Construction and characterization of an expressed sequenced tag library for the mosquito vector Armigeres subalbatus

    PubMed Central

    Mayhew, George F; Bartholomay, Lyric C; Kou, Hang-Yen; Rocheleau, Thomas A; Fuchs, Jeremy F; Aliota, Matthew T; Tsao, I-Yu; Huang, Chiung-Yen; Liu, Tze-Tze; Hsiao, Kwang-Jen; Tsai, Shih-Feng; Yang, Ueng-Cheng; Perna, Nicole T; Cho, Wen-Long; Christensen, Bruce M; Chen, Cheng-Chen

    2007-01-01

    Background The mosquito, Armigeres subalbatus, mounts a distinctively robust innate immune response when infected with the nematode Brugia malayi, a causative agent of lymphatic filariasis. In order to mine the transcriptome for new insight into the cascade of events that takes place in response to infection in this mosquito, 6 cDNA libraries were generated from tissues of adult female mosquitoes subjected to immune-response activation treatments that lead to well-characterized responses, and from aging, naïve mosquitoes. Expressed sequence tags (ESTs) from each library were produced, annotated, and subjected to comparative analyses. Results Six libraries were constructed and used to generate 44,940 expressed sequence tags, of which 38,079 passed quality filters to be included in the annotation project and subsequent analyses. All of these sequences were collapsed into clusters resulting in 8,020 unique sequence clusters or singletons. EST clusters were annotated and curated manually within ASAP (A Systematic Annotation Package for Community Analysis of Genomes) web portal according to BLAST results from comparisons to Genbank, and the Anopheles gambiae and Drosophila melanogaster genome projects. Conclusion The resulting dataset is the first of its kind for this mosquito vector and provides a basis for future studies of mosquito vectors regarding the cascade of events that occurs in response to infection, and thereby providing insight into vector competence and innate immunity. PMID:18088419

  11. Exogenous gypsy insulator sequences modulate transgene expression in the malaria vector mosquito, Anopheles stephensi.

    PubMed

    Carballar-Lejarazú, Rebeca; Jasinskiene, Nijole; James, Anthony A

    2013-04-30

    Malaria parasites are transmitted to humans by mosquitoes of the genus Anopheles, and these insects are the targets of innovative vector control programs. Proposed approaches include the use of genetic strategies based on transgenic mosquitoes to suppress or modify vector populations. Although substantial advances have been made in engineering resistant mosquito strains, limited efforts have been made in refining mosquito transgene expression, in particular attenuating the effects of insertions sites, which can result in variations in phenotypes and impacts on fitness due to the random integration of transposon constructs. A promising strategy to mitigate position effects is the identification of insulator or boundary DNA elements that could be used to isolate transgenes from the effects of their genomic environment. We applied quantitative approaches that show that exogenous insulator-like DNA derived from the Drosophila melanogaster gypsy retrotransposon can increase and stabilize transgene expression in transposon-mediated random insertions and recombinase-catalyzed, site-specific integrations in the malaria vector mosquito, Anopheles stephensi. These sequences can contribute to precise expression of transgenes in mosquitoes engineered for both basic and applied goals. PMID:23584017

  12. Potential impacts of climate change on the ecology of dengue and its mosquito vector the Asian tiger mosquito (Aedes albopictus)

    NASA Astrophysics Data System (ADS)

    Erickson, R. A.; Hayhoe, K.; Presley, S. M.; Allen, L. J. S.; Long, K. R.; Cox, S. B.

    2012-09-01

    Shifts in temperature and precipitation patterns caused by global climate change may have profound impacts on the ecology of certain infectious diseases. We examine the potential impacts of climate change on the transmission and maintenance dynamics of dengue, a resurging mosquito-vectored infectious disease. In particular, we project changes in dengue season length for three cities: Atlanta, GA; Chicago, IL and Lubbock, TX. These cities are located on the edges of the range of the Asian tiger mosquito within the United States of America and were chosen as test cases. We use a disease model that explicitly incorporates mosquito population dynamics and high-resolution climate projections. Based on projected changes under the Special Report on Emissions Scenarios (SRES) A1fi (higher) and B1 (lower) emission scenarios as simulated by four global climate models, we found that the projected warming shortened mosquito lifespan, which in turn decreased the potential dengue season. These results illustrate the difficulty in predicting how climate change may alter complex systems.

  13. Chitosan/interfering RNA nanoparticle mediated gene silencing in disease vector mosquito larvae.

    PubMed

    Zhang, Xin; Mysore, Keshava; Flannery, Ellen; Michel, Kristin; Severson, David W; Zhu, Kun Yan; Duman-Scheel, Molly

    2015-01-01

    Vector mosquitoes inflict more human suffering than any other organism-and kill more than one million people each year. The mosquito genome projects facilitated research in new facets of mosquito biology, including functional genetic studies in the primary African malaria vector Anopheles gambiae and the dengue and yellow fever vector Aedes aegypti. RNA interference- (RNAi-) mediated gene silencing has been used to target genes of interest in both of these disease vector mosquito species. Here, we describe a procedure for preparation of chitosan/interfering RNA nanoparticles that are combined with food and ingested by larvae. This technically straightforward, high-throughput, and relatively inexpensive methodology, which is compatible with long double stranded RNA (dsRNA) or small interfering RNA (siRNA) molecules, has been used for the successful knockdown of a number of different genes in A. gambiae and A. aegypti larvae. Following larval feedings, knockdown, which is verified through qRT-PCR or in situ hybridization, can persist at least through the late pupal stage. This methodology may be applicable to a wide variety of mosquito and other insect species, including agricultural pests, as well as other non-model organisms. In addition to its utility in the research laboratory, in the future, chitosan, an inexpensive, non-toxic and biodegradable polymer, could potentially be utilized in the field. PMID:25867635

  14. Host Feeding Patterns of Established and Potential Mosquito Vectors of West Nile Virus in the Eastern United States

    PubMed Central

    APPERSON, CHARLES S.; HASSAN, HASSAN K.; HARRISON, BRUCE A.; SAVAGE, HARRY M.; ASPEN, STEPHEN E.; FARAJOLLAHI, ARY; CRANS, WAYNE; DANIELS, THOMAS J.; FALCO, RICHARD C.; BENEDICT, MARK; ANDERSON, MICHAEL; McMILLEN, LARRY; UNNASCH, THOMAS R.

    2008-01-01

    An important variable in determining the vectorial capacity of mosquito species for arthropod-borne infections is the degree of contact of the vector and the vertebrate reservoir. This parameter can be estimated by examining the host-feeding habits of vectors. Serological and polymerase chain reaction based methods have been used to study the host-feedings patterns of 21 mosquito species from New York, New Jersey, and Tennessee, 19 of which previously have been found infected with West Nile virus. Mammalophilic mosquito species in New Jersey and New York fed primarily upon white-tailed deer, while those from Memphis, Tennessee, fed mainly upon domestic dogs. A total of 24 different avian host species were detected among the avian-derived blood meals. American Robin, Northern Cardinal, Northern Mockingbird, Tufted Titmouse, and Brown-headed Cowbird were common avian hosts, while blood meals derived from the American Crow were relatively rare. Although the majority of common host species were potentially among the most abundant birds at each location, the proportion of blood meals from the most commonly fed upon avian species was greater than was predicted based upon the likely abundance of these species alone. These findings suggest that vector species for West Nile virus may preferentially feed upon certain avian hosts. PMID:15018775

  15. Vector–Host Interactions in Avian Nests: Do Mosquitoes Prefer Nestlings over Adults?

    PubMed Central

    Burkett-Cadena, Nathan D.; Ligon, Russell A.; Liu, Mark; Hassan, Hassan K.; Hill, Geoffrey E.; Eubanks, Micky D.; Unnasch, Thomas R.

    2010-01-01

    The hypothesis that nestlings are a significant driver of arbovirus transmission and amplification is based upon findings that suggest nestlings are highly susceptible to being fed upon by vector mosquitoes and to viral infection and replication. Several previous studies have suggested that nestlings are preferentially fed upon relative to adults in the nest, and other studies have reported a preference for adults over nestlings. We directly tested the feeding preference of nestling and adult birds in a natural setting, introducing mosquitoes into nesting boxes containing eastern bluebirds (Sialia sialis), collecting blood-fed mosquitoes, and matching the source of mosquito blood meals to individual birds using microsatellite markers. Neither nestlings nor adults were fed upon to an extent significantly greater than would be predicted based upon their relative abundance in the nests, although feeding upon mothers decreased as the age of the nestlings increased. PMID:20682889

  16. Vector-host interactions in avian nests: do mosquitoes prefer nestlings over adults?

    PubMed

    Burkett-Cadena, Nathan D; Ligon, Russell A; Liu, Mark; Hassan, Hassan K; Hill, Geoffrey E; Eubanks, Micky D; Unnasch, Thomas R

    2010-08-01

    The hypothesis that nestlings are a significant driver of arbovirus transmission and amplification is based upon findings that suggest nestlings are highly susceptible to being fed upon by vector mosquitoes and to viral infection and replication. Several previous studies have suggested that nestlings are preferentially fed upon relative to adults in the nest, and other studies have reported a preference for adults over nestlings. We directly tested the feeding preference of nestling and adult birds in a natural setting, introducing mosquitoes into nesting boxes containing eastern bluebirds (Sialia sialis), collecting blood-fed mosquitoes, and matching the source of mosquito blood meals to individual birds using microsatellite markers. Neither nestlings nor adults were fed upon to an extent significantly greater than would be predicted based upon their relative abundance in the nests, although feeding upon mothers decreased as the age of the nestlings increased. PMID:20682889

  17. Using global information technology to detect, monitor, and control mosquito pest and disease vector populations.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geographic Information Systems (GIS), image analysis, and remote sensing comprise global information technologies that are used to characterize pest and vector populations of mosquitoes. At this national meeting, scientists from ARS and McNeese State University organized and convened a half-day sym...

  18. Existing Infection Facilitates Establishment and Density of Malaria Parasites in Their Mosquito Vector

    PubMed Central

    Pollitt, Laura C.; Bram, Joshua T.; Blanford, Simon; Jones, Matthew J.; Read, Andrew F.

    2015-01-01

    Very little is known about how vector-borne pathogens interact within their vector and how this impacts transmission. Here we show that mosquitoes can accumulate mixed strain malaria infections after feeding on multiple hosts. We found that parasites have a greater chance of establishing and reach higher densities if another strain is already present in a mosquito. Mixed infections contained more parasites but these larger populations did not have a detectable impact on vector survival. Together these results suggest that mosquitoes taking multiple infective bites may disproportionally contribute to malaria transmission. This will increase rates of mixed infections in vertebrate hosts, with implications for the evolution of parasite virulence and the spread of drug-resistant strains. Moreover, control measures that reduce parasite prevalence in vertebrate hosts will reduce the likelihood of mosquitoes taking multiple infective feeds, and thus disproportionally reduce transmission. More generally, our study shows that the types of strain interactions detected in vertebrate hosts cannot necessarily be extrapolated to vectors. PMID:26181518

  19. Efficacy of extracts of Bacillus thuringiensis israelensis for the control of mosquito vectors.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than 1 million human cases of Chikungunya were recently reported in India. Aedes aegypti (the yellow fever mosquito) is an important disease vector in India where it transmits Chikungunya, dengue, and yellow fever viruses to humans. In this study, scientists from Bharathiar University in Coim...

  20. Infection and Dissemination of Venezuelan Equine Encephalitis Virus in the Epidemic Mosquito Vector, Aedes taeniorhynchus

    Microsoft Academic Search

    Darci R. Smith; Nicole C. Arrigo; Grace Leal; Linda E. Muehlberger; Scott C. Weaver

    The mosquito Aedes taeniorhynchus is an important epidemic vector of Venezuelan equine encephalitis virus (VEEV), but detailed studies of its infection are lacking. We compared infection by an epidemic VEEV strain to that by an enzootic strain using virus titrations, immunohistochemistry, and a virus expressing the green fluorescent protein. Ae. taeniorhynchus was more susceptible to the epidemic strain, which initially

  1. Cytochrome B Analysis of Mosquito Blood Meals: Identifying Wildlife Hosts of West Nile Virus Mosquito Vectors in Wyoming, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Female mosquitoes commonly exhibit patterns of blood feeding from vertebrate hosts, a behavior that strongly influences mosquito pathogen infection and transmission. The vertebrate host dynamics of the mosquito transmitted arbovirus, West Nile virus (family Flaviviridae, genus Flavivirus, WNV) in sa...

  2. The Vector Population Monitoring Tool (VPMT): High-Throughput DNA-Based Diagnostics for the Monitoring of Mosquito Vector Populations

    PubMed Central

    Bass, Chris; Nikou, Dimitra; Vontas, John; Donnelly, Martin J.; Williamson, Martin S.; Field, Linda M.

    2010-01-01

    Regular monitoring of mosquito vector populations is an integral component of most vector control programmes. Contemporary data on mosquito species composition, infection status, and resistance to insecticides are a prerequisite for effective intervention. For this purpose we, with funding from the Innovative Vector Control Consortium (IVCC), have developed a suite of high-throughput assays based on a single “closed-tube” platform that collectively comprise the “Vector Population Monitoring Tool” (VPMT). The VPMT can be used to screen mosquito disease vector populations for a number of traits including Anopheles gambiae s.l. and Anopheles funestus species identification, detection of infection with Plasmodium parasites, and identification of insecticide resistance mechanisms. In this paper we focus on the Anopheles-specific assays that comprise the VPMT and include details of a new assay for resistance todieldrin Rdl detection. The application of these tools, general and specific guidelines on their use based on field testing in Africa, and plans for further development are discussed. PMID:22347668

  3. Phylogenetic analyses of vector mosquito basic helix-loop-helix transcription factors.

    PubMed

    Zhang, D B; Wang, Y; Liu, A K; Wang, X H; Dang, C W; Yao, Q; Chen, K P

    2013-10-01

    Basic helix-loop-helix (bHLH) transcription factors play critical roles in the regulation of a wide range of developmental processes in higher organisms and have been identified in more than 20 organisms. Mosquitoes are important vectors of certain human diseases. In this study, Aedes aegypti, Anopheles gambiae str. PEST and Culex quinquefasciatus genomes were found to encode 55, 55 and 57 bHLH genes, respectively. Further phylogenetic analyses and OrthoDB and Kyoto encyclopedia of genes and genomes orthology database searches led us to define orthology for all the identified mosquito bHLHs successfully. This provides useful information with which to update annotations to 40 Ae.?aegypti, 55 An.?gambiae and 38 C.?quinquefasciatus?bHLH genes in VectorBase. The mosquito lineage has more bHLH genes in the Atonal, neurogenin (Ngn) and Hes-related with YRPW motif (Hey) families than do other insect species, suggesting that mosquitoes have evolved to be more sensitive to vibration, light and chemicals. Mosquito bHLH genes generally have higher evolutionary rates than other insect species. However, no pervasive positive selection occurred in the evolution of insect bHLH genes. Only episodic positive selection was found to affect evolution of bHLH genes in 11 families. Besides, coding regions of several Ae.?aegypti?bHLH motifs have unusually long introns in which multiple copies of transposable elements have been identified. These data provide a solid basis for further studies on structures and functions of bHLH proteins in the regulation of mosquito development and for prevention and control of mosquito-mediated human diseases. PMID:23906262

  4. Insect-specific viruses detected in laboratory mosquito colonies and their potential implications for experiments evaluating arbovirus vector competence.

    PubMed

    Bolling, Bethany G; Vasilakis, Nikos; Guzman, Hilda; Widen, Steven G; Wood, Thomas G; Popov, Vsevolod L; Thangamani, Saravanan; Tesh, Robert B

    2015-02-01

    Recently, there has been a dramatic increase in the detection and characterization of insect-specific viruses in field-collected mosquitoes. Evidence suggests that these viruses are ubiquitous in nature and that many are maintained by vertical transmission in mosquito populations. Some studies suggest that the presence of insect-specific viruses may inhibit replication of a super-infecting arbovirus, thus altering vector competence of the mosquito host. Accordingly, we screened our laboratory mosquito colonies for insect-specific viruses. Pools of colony mosquitoes were homogenized and inoculated into cultures of Aedes albopictus (C6/36) cells. The infected cells were examined by electron microscopy and deep sequencing was performed on RNA extracts. Electron micrograph images indicated the presence of three different viruses in three of our laboratory mosquito colonies. Potential implications of these findings for vector competence studies are discussed. PMID:25510714

  5. Evolutionary Dynamics of Immune-Related Genes and Pathways in Disease-Vector Mosquitoes

    PubMed Central

    Waterhouse, Robert M.; Kriventseva, Evgenia V.; Meister, Stephan; Xi, Zhiyong; Alvarez, Kanwal S.; Bartholomay, Lyric C.; Barillas-Mury, Carolina; Bian, Guowu; Blandin, Stephanie; Christensen, Bruce M.; Dong, Yuemei; Jiang, Haobo; Kanost, Michael R.; Koutsos, Anastasios C.; Levashina, Elena A.; Li, Jianyong; Ligoxygakis, Petros; MacCallum, Robert M.; Mayhew, George F.; Mendes, Antonio; Michel, Kristin; Osta, Mike A.; Paskewitz, Susan; Shin, Sang Woon; Vlachou, Dina; Wang, Lihui; Wei, Weiqi; Zheng, Liangbiao; Zou, Zhen; Severson, David W.; Raikhel, Alexander S.; Kafatos, Fotis C.; Dimopoulos, George; Zdobnov, Evgeny M.; Christophides, George K.

    2007-01-01

    Mosquitoes are vectors of parasitic and viral diseases of immense importance for public health. The acquisition of the genome sequence of the yellow fever and Dengue vector, Aedes aegypti (Aa), has enabled a comparative phylogenomic analysis of the insect immune repertoire: in Aa, the malaria vector Anopheles gambiae (Ag), and the fruit fly Drosophila melanogaster (Dm). Analysis of immune signaling pathways and response modules reveals both conservative and rapidly evolving features associated with different functional gene categories and particular aspects of immune reactions. These dynamics reflect in part continuous readjustment between accommodation and rejection of pathogens and suggest how innate immunity may have evolved. PMID:17588928

  6. Comparative responses of mosquito vectors of West Nile virus to light traps augmented with chemical attractant and to human hosts.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scientists in the USA seek to develop Global Information Technology (GIS, GPS, remote sensing)-based systems that can be used to deploy sentinel traps for mosquito vectors and for the implementation and evaluation of mosquito control. Achieving this objective requires the development of methods for...

  7. Sheep Skin Odor Improves Trap Captures of Mosquito Vectors of Rift Valley Fever

    PubMed Central

    Tchouassi, David P.; Sang, Rosemary; Sole, Catherine L.; Bastos, Armanda D. S.; Mithoefer, Klaus; Torto, Baldwyn

    2012-01-01

    In recent years, the East African region has seen an increase in arboviral diseases transmitted by blood-feeding arthropods. Effective surveillance to monitor and reduce incidence of these infections requires the use of appropriate vector sampling tools. Here, trapped skin volatiles on fur from sheep, a known preferred host of mosquito vectors of Rift Valley fever virus (RVFV), were used with a standard CDC light trap to improve catches of mosquito vectors. We tested the standard CDC light trap alone (L), and baited with (a) CO2 (LC), (b) animal volatiles (LF), and (c) CO2 plus animal volatiles (LCF) in two highly endemic areas for RVF in Kenya (Marigat and Ijara districts) from March–June and September–December 2010. The incidence rate ratios (IRR) that mosquito species chose traps baited with treatments (LCF, LC and LF) instead of the control (L) were estimated. Marigat was dominated by secondary vectors and host-seeking mosquitoes were 3–4 times more likely to enter LC and LCF traps [IRR?=?3.1 and IRR?=?3.8 respectively] than the L only trap. The LCF trap captured a greater number of mosquitoes than the LC trap (IRR?=?1.23) although the difference was not significant. Analogous results were observed at Ijara, where species were dominated by key primary and primary RVFV vectors, with 1.6-, 6.5-, and 8.5-fold increases in trap captures recorded in LF, LC and LCF baited traps respectively, relative to the control. These catches all differed significantly from those trapped in L only. Further, there was a significant increase in trap captures in LCF compared to LC (IRR?=?1.63). Mosquito species composition and trap counts differed between the RVF sites. However, within each site, catches differed in abundance only and no species preferences were noted in the different baited-traps. Identifying the attractive components present in these natural odors should lead to development of an effective odor-bait trapping system for population density-monitoring and result in improved RVF surveillance especially during the inter-epidemic period. PMID:23133687

  8. Sheep skin odor improves trap captures of mosquito vectors of Rift Valley fever.

    PubMed

    Tchouassi, David P; Sang, Rosemary; Sole, Catherine L; Bastos, Armanda D S; Mithoefer, Klaus; Torto, Baldwyn

    2012-01-01

    In recent years, the East African region has seen an increase in arboviral diseases transmitted by blood-feeding arthropods. Effective surveillance to monitor and reduce incidence of these infections requires the use of appropriate vector sampling tools. Here, trapped skin volatiles on fur from sheep, a known preferred host of mosquito vectors of Rift Valley fever virus (RVFV), were used with a standard CDC light trap to improve catches of mosquito vectors. We tested the standard CDC light trap alone (L), and baited with (a) CO(2) (LC), (b) animal volatiles (LF), and (c) CO(2) plus animal volatiles (LCF) in two highly endemic areas for RVF in Kenya (Marigat and Ijara districts) from March-June and September-December 2010. The incidence rate ratios (IRR) that mosquito species chose traps baited with treatments (LCF, LC and LF) instead of the control (L) were estimated. Marigat was dominated by secondary vectors and host-seeking mosquitoes were 3-4 times more likely to enter LC and LCF traps [IRR?=?3.1 and IRR?=?3.8 respectively] than the L only trap. The LCF trap captured a greater number of mosquitoes than the LC trap (IRR?=?1.23) although the difference was not significant. Analogous results were observed at Ijara, where species were dominated by key primary and primary RVFV vectors, with 1.6-, 6.5-, and 8.5-fold increases in trap captures recorded in LF, LC and LCF baited traps respectively, relative to the control. These catches all differed significantly from those trapped in L only. Further, there was a significant increase in trap captures in LCF compared to LC (IRR?=?1.63). Mosquito species composition and trap counts differed between the RVF sites. However, within each site, catches differed in abundance only and no species preferences were noted in the different baited-traps. Identifying the attractive components present in these natural odors should lead to development of an effective odor-bait trapping system for population density-monitoring and result in improved RVF surveillance especially during the inter-epidemic period. PMID:23133687

  9. Infection and dissemination of Venezuelan equine encephalitis virus in the epidemic mosquito vector, Aedes taeniorhynchus.

    PubMed

    Smith, Darci R; Arrigo, Nicole C; Leal, Grace; Muehlberger, Linda E; Weaver, Scott C

    2007-07-01

    The mosquito Aedes taeniorhynchus is an important epidemic vector of Venezuelan equine encephalitis virus (VEEV), but detailed studies of its infection are lacking. We compared infection by an epidemic VEEV strain to that by an enzootic strain using virus titrations, immunohistochemistry, and a virus expressing the green fluorescent protein. Ae. taeniorhynchus was more susceptible to the epidemic strain, which initially infected the posterior midgut and occasionally the anterior midgut and cardia. Once dissemination beyond the midgut occurred, virus was present in nearly all tissues. Transmission of the epidemic strain to mice was first detected 4 days after infection. In contrast, the enzootic strain did not efficiently infect midgut cells but replicated in muscles and nervous tissue on dissemination. Because VEEV emergence can depend on adaptation to epidemic vectors, these results show that epidemic/enzootic strain comparisons not only comprise a useful model system to study alphavirus transmission by mosquitoes, but also have important public health implications. PMID:17620651

  10. Turning cigarette butt waste into an alternative control tool against an insecticide-resistant mosquito vector.

    PubMed

    Dieng, Hamady; Rajasaygar, Sudha; Ahmad, Abu Hassan; Ahmad, Hamdan; Rawi, Che Salmah Md; Zuharah, Wan Fatma; Satho, Tomomitsu; Miake, Fumio; Fukumitsu, Yuki; Saad, Ahmad Ramli; Ghani, Idris Abd; Vargas, Ronald Enrique Morales; Majid, Abdul Hafiz Ab; Abubakar, Sazaly

    2013-12-01

    Annually, 4.5 trillion cigarette butts (CBs) are flicked into our environment. Evidence exists that CB waste is deadly to aquatic life, but their lethality to the aquatic life of the main dengue vector is unknown. CBs are full of toxicants that occur naturally, during planting and manufacturing, which may act as larvicidal agents. We assessed Aedes aegypti vulnerability to Marlboro butts during its development. Overall, CBs showed insecticidal activities against larvae. At early phases of development, mortality rates were much higher in two CBs solution (2CBSol) and 3CBSol microcosms (MICRs). Larval survival gradually decreased with development in 1CBSol-MICRs. However, in great presence of CBs, mortality was high even for the late developmental stages. These results suggest that A. aegypti larvae are vulnerable to CB presence in their habitats, but this effect was seen most during the early developmental phases and in the presence of increased amounts of cigarette remnants. CB filters are being used as raw material in many sectors, i.e., brick, art, fashion, plastic industries, as a practical solution to the pollution problem, the observed butt waste toxicity to mosquito larvae open new avenues for the identification of novel insecticide products. PMID:23999373

  11. Identification of microRNAs expressed in two mosquito vectors, Aedes albopictus and Culex quinquefasciatus

    Microsoft Academic Search

    Rebecca L Skalsky; Dana L Vanlandingham; Frank Scholle; Stephen Higgs; Bryan R Cullen

    2010-01-01

    BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression in a variety of organisms, including insects, vertebrates, and plants. miRNAs play important roles in cell development and differentiation as well as in the cellular response to stress and infection. To date, there are limited reports of miRNA identification in mosquitoes, insects that act as essential vectors for

  12. West Nile Virus Vector Competency of Culex quinquefasciatus Mosquitoes in the Galápagos Islands

    PubMed Central

    Eastwood, Gillian; Kramer, Laura D.; Goodman, Simon J.; Cunningham, Andrew A.

    2011-01-01

    The mosquito-transmitted pathogen West Nile virus (WNV) is not yet present in the Galápagos Archipelago of Ecuador. However, concern exists for fragile endemic island fauna after population decreases in several North American bird species and pathology in certain reptiles. We examined WNV vector competency of a Galápagos strain of mosquito (Culex quinquefasciatus Say). Field specimens were tested for their capacity to transmit the WN02-1956 strain of WNV after incubation at 27°C or 30°C. Rates of infection, dissemination, and transmission all increased with days post-exposure to WNV, and the highest rates were observed at 28 days. Infection rates peaked at 59% and transmission rates peaked at 44% (of mosquitoes tested). Vector efficiency increased after day 14. Rates of infection but not of transmission were significantly influence by temperature. No vertical transmission was detectable. We demonstrate that Galápagos Cx. quinquefasciatus are competent WNV vectors, and therefore should be considered an animal and public health risk for the islands and controlled wherever possible. PMID:21896799

  13. Determining the spatial autocorrelation of dengue vector populations: influences of mosquito sampling method, covariables, and vector control.

    PubMed

    Azil, Aishah H; Bruce, David; Williams, Craig R

    2014-06-01

    We investigated spatial autocorrelation of female Aedes aegypti L. mosquito abundance from BG-Sentinel trap and sticky ovitrap collections in Cairns, north Queensland, Australia. BG-Sentinel trap collections in 2010 show a significant spatial autocorrelation across the study site and over a smaller spatial extent, while sticky ovitrap collections only indicate a non-significant, weak spatial autocorrelation. The BG-Sentinel trap collections were suitable for spatial interpolation using ordinary kriging and cokriging techniques. The uses of Premise Condition Index and potential breeding container data have helped improve our prediction of vector abundance. Semiovariograms and prediction maps indicate that the spatial autocorrelation of mosquito abundance determined by BG-Sentinel traps extends farther compared to sticky ovitrap collections. Based on our data, fewer BG-Sentinel traps are required to represent vector abundance at a series of houses compared to sticky ovitraps. A lack of spatial structure was observed following vector control treatment in the area. This finding has implications for the design and costs of dengue vector surveillance programs. PMID:24820568

  14. Anopheles plumbeus (Diptera: Culicidae) in Europe: a mere nuisance mosquito or potential malaria vector?

    PubMed Central

    2012-01-01

    Background Anopheles plumbeus has been recognized as a minor vector for human malaria in Europe since the beginning of the 20th century. In recent years this tree hole breeding mosquito species appears to have exploited novel breeding sites, including large and organically rich man-made containers, with consequently larger mosquito populations in close vicinity to humans. This lead to investigate whether current populations of An. plumbeus would be able to efficiently transmit Plasmodium falciparum, the parasite responsible for the most deadly form of malaria. Methods Anopheles plumbeus immatures were collected from a liquid manure pit in Switzerland and transferred as adults to the CEPIA (Institut Pasteur, France) where they were fed on P. falciparum gametocytes produced in vitro. Anopheles gambiae mosquitoes served as controls. Development of P. falciparum in both mosquito species was followed by microscopical detection of oocysts on mosquito midguts and by sporozoite detection in the head/thorax by PCR and microscopy. Results A total of 293 wild An. plumbeus females from four independent collections successfully fed through a membrane on blood containing P. falciparum gametocytes. Oocysts were observed in mosquito midguts and P. falciparum DNA was detected in head-thorax samples in all four experiments, demonstrating, on a large mosquito sample, that An. plumbeus is indeed receptive to P. falciparum NF54 and able to produce sporozoites. Importantly, the proportion of sporozoites-infected An. plumbeus was almost similar to that of An. gambiae (31 to 88% An. plumbeus versus 67 to 97% An. gambiae). However, the number of sporozoites produced was significantly lower in infected An. plumbeus. Conclusion The results show that a sample of field-caught An. plumbeus has a moderate to high receptivity towards P. falciparum. Considering the increased mobility of humans between Europe and malaria endemic countries and changes in environment and climate, these data strongly suggest that An. plumbeus could act as a vector for malaria and thus significantly contribute to increasing the malaria transmission risk in Central-Western Europe. In locations showing high vulnerability to the presence of gametocyte carriers, the risk of transmission of malaria by An. plumbeus should be considered. PMID:23181931

  15. Laboratory evaluation of Indian medicinal plants as repellents against malaria, dengue, and filariasis vector mosquitoes.

    PubMed

    Govindarajan, Marimuthu; Sivakumar, Rajamohan

    2015-02-01

    Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. 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. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticides, in the present study, the repellent activity of crude hexane, ethyl acetate, benzene, chloroform, and methanol extracts of leaf of Erythrina indica and root of Asparagus racemosus were assayed for their repellency against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The crude extract was applied on a membrane used for membrane feeding of unfed mosquitoes in a 1-ft cage. About 50 unfed 3-4-day-old laboratory-reared pathogen-free strains of A. stephensi, A. aegypti, and C. quinquefasciatus were introduced in a 1-ft cage fitted with a membrane with blood for feeding with temperature maintained at 37 °C through circulating water bath maintained at 40-45 °C. Three concentrations (1.0, 2.0, and 5.0 mg/cm(2)) of the crude extracts were evaluated. Repellents in E. indica afforded longer protection time against A. stephensi, A. aegypti, and C. quinquefasciatus than those in A. racemosus at 5.0 mg/cm(2) concentration, and the mean complete protection time ranged from 120 to 210 min with the different extracts tested. In this observation, these two plant crude extracts gave protection against mosquito bites; also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf extract of E. indica and root extract of A. racemosus have the potential to be used as an ideal eco-friendly approach for the control of mosquitoes. This is the first report on the mosquito repellent activity of the reported A. racemosus and E. indica plants. PMID:25399815

  16. Mosquito vector diversity across habitats in central Thailand endemic for dengue and other arthropod-borne diseases.

    PubMed

    Thongsripong, Panpim; Green, Amy; Kittayapong, Pattamaporn; Kapan, Durrell; Wilcox, Bruce; Bennett, Shannon

    2013-01-01

    Recent years have seen the greatest ecological disturbances of our times, with global human expansion, species and habitat loss, climate change, and the emergence of new and previously-known infectious diseases. Biodiversity loss affects infectious disease risk by disrupting normal relationships between hosts and pathogens. Mosquito-borne pathogens respond to changing dynamics on multiple transmission levels and appear to increase in disturbed systems, yet current knowledge of mosquito diversity and the relative abundance of vectors as a function of habitat change is limited. We characterize mosquito communities across habitats with differing levels of anthropogenic ecological disturbance in central Thailand. During the 2008 rainy season, adult mosquito collections from 24 sites, representing 6 habitat types ranging from forest to urban, yielded 62,126 intact female mosquitoes (83,325 total mosquitoes) that were assigned to 109 taxa. Female mosquito abundance was highest in rice fields and lowest in forests. Diversity indices and rarefied species richness estimates indicate the mosquito fauna was more diverse in rural and less diverse in rice field habitats, while extrapolated estimates of true richness (Chao1 and ACE) indicated higher diversity in the forest and fragmented forest habitats and lower diversity in the urban. Culex sp. (Vishnui subgroup) was the most common taxon found overall and the most frequent in fragmented forest, rice field, rural, and suburban habitats. The distributions of species of medical importance differed significantly across habitat types and were always lowest in the intact, forest habitat. The relative abundance of key vector species, Aedes aegypti and Culex quinquefasciatus, was negatively correlated with diversity, suggesting that direct species interactions and/or habitat-mediated factors differentially affecting invasive disease vectors may be important mechanisms linking biodiversity loss to human health. Our results are an important first step for understanding the dynamics of mosquito vector distributions under changing environmental features across landscapes of Thailand. PMID:24205420

  17. Mosquito Vector Diversity across Habitats in Central Thailand Endemic for Dengue and Other Arthropod-Borne Diseases

    PubMed Central

    Thongsripong, Panpim; Green, Amy; Kittayapong, Pattamaporn; Kapan, Durrell; Wilcox, Bruce; Bennett, Shannon

    2013-01-01

    Recent years have seen the greatest ecological disturbances of our times, with global human expansion, species and habitat loss, climate change, and the emergence of new and previously-known infectious diseases. Biodiversity loss affects infectious disease risk by disrupting normal relationships between hosts and pathogens. Mosquito-borne pathogens respond to changing dynamics on multiple transmission levels and appear to increase in disturbed systems, yet current knowledge of mosquito diversity and the relative abundance of vectors as a function of habitat change is limited. We characterize mosquito communities across habitats with differing levels of anthropogenic ecological disturbance in central Thailand. During the 2008 rainy season, adult mosquito collections from 24 sites, representing 6 habitat types ranging from forest to urban, yielded 62,126 intact female mosquitoes (83,325 total mosquitoes) that were assigned to 109 taxa. Female mosquito abundance was highest in rice fields and lowest in forests. Diversity indices and rarefied species richness estimates indicate the mosquito fauna was more diverse in rural and less diverse in rice field habitats, while extrapolated estimates of true richness (Chao1 and ACE) indicated higher diversity in the forest and fragmented forest habitats and lower diversity in the urban. Culex sp. (Vishnui subgroup) was the most common taxon found overall and the most frequent in fragmented forest, rice field, rural, and suburban habitats. The distributions of species of medical importance differed significantly across habitat types and were always lowest in the intact, forest habitat. The relative abundance of key vector species, Aedes aegypti and Culex quinquefasciatus, was negatively correlated with diversity, suggesting that direct species interactions and/or habitat-mediated factors differentially affecting invasive disease vectors may be important mechanisms linking biodiversity loss to human health. Our results are an important first step for understanding the dynamics of mosquito vector distributions under changing environmental features across landscapes of Thailand. PMID:24205420

  18. Development of a population suppression strain of the human malaria vector mosquito, Anopheles stephensi

    PubMed Central

    2013-01-01

    Background Transgenic mosquito strains are being developed to contribute to the control of dengue and malaria transmission. One approach uses genetic manipulation to confer conditional, female-specific dominant lethality phenotypes. Engineering of a female-specific flightless phenotype provides a sexing mechanism essential for male-only mosquito, release approaches that result in population suppression of target vector species. Methods An approach that uses a female-specific gene promoter and antibiotic-repressible lethal factor to produce a sex-specific flightless phenotype was adapted to the human malaria vector, Anopheles stephensi. Transposon- and site-specific recombination-mediated technologies were used to generate a number of transgenic An. stephensi lines that when combined through mating produced the phenotype of flight-inhibited females and flight-capable males. Results The data shown here demonstrate the successful engineering of a female-specific flightless phenotype in a malaria vector. The flightless phenotype was repressible by the addition of tetracycline to the larval diet. This conditional phenotype allows the rearing of the strains under routine laboratory conditions. The minimal level of tetracycline that rescues the flightless phenotype is higher than that found as an environmental contaminant in circumstances where there is intensive use of antibiotics. Conclusions These studies support the further development of flightless female technology for applications in malaria control programmes that target the vectors. PMID:23622561

  19. Early warning of West Nile virus mosquito vector: climate and land use models successfully explain phenology and abundance of Culex pipiens mosquitoes in north-western Italy

    PubMed Central

    2014-01-01

    Background West Nile Virus (WNV) is an emerging global health threat. Transmission risk is strongly related to the abundance of mosquito vectors, typically Culex pipiens in Europe. Early-warning predictors of mosquito population dynamics would therefore help guide entomological surveillance and thereby facilitate early warnings of transmission risk. Methods We analysed an 11-year time series (2001 to 2011) of Cx. pipiens mosquito captures from the Piedmont region of north-western Italy to determine the principal drivers of mosquito population dynamics. Linear mixed models were implemented to examine the relationship between Cx. pipiens population dynamics and environmental predictors including temperature, precipitation, Normalized Difference Water Index (NDWI) and the proximity of mosquito traps to urban areas and rice fields. Results Warm temperatures early in the year were associated with an earlier start to the mosquito season and increased season length, and later in the year, with decreased abundance. Early precipitation delayed the start and shortened the length of the mosquito season, but increased total abundance. Conversely, precipitation later in the year was associated with a longer season. Finally, higher NDWI early in the year was associated with an earlier start to the season and increased season length, but was not associated with abundance. Proximity to rice fields predicted higher total abundance when included in some models, but was not a significant predictor of phenology. Proximity to urban areas was not a significant predictor in any of our models. Predicted variations in start of the season and season length ranged from one to three weeks, across the measured range of variables. Predicted mosquito abundance was highly variable, with numbers in excess of 1000 per trap per year when late season temperatures were low (average 21°C) to only 150 when late season temperatures were high (average 30°C). Conclusions Climate data collected early in the year, in conjunction with local land use, can be used to provide early warning of both the timing and magnitude of mosquito outbreaks. This potentially allows targeted mosquito control measures to be implemented, with implications for prevention and control of West Nile Virus and other mosquito borne diseases. PMID:24924622

  20. Global Climate Change and Its Potential Impact on Disease Transmission by Salinity-Tolerant Mosquito Vectors in Coastal Zones

    PubMed Central

    Ramasamy, Ranjan; Surendran, Sinnathamby Noble

    2012-01-01

    Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with <0.5?ppt or parts per thousand, 0.5–30?ppt and >30?ppt salt are termed fresh, brackish, and saline respectively) will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross–McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase the densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti, and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased coastal transmission of mosquito-borne diseases consequent to climate change and a rise in sea levels. It is proposed that the Jaffna peninsula in Sri Lanka may be a useful case study for the impact of rising sea levels on mosquito vectors in tropical coasts. PMID:22723781

  1. Evaluation of repellent activities of Cymbopogon essential oils against mosquito vectors of Malaria, Filariasis and Dengue Fever in India.

    PubMed

    Tyagi, B K; Shahi, A K; Kaul, B L

    1998-08-01

    Essential oils of four species and two hybrid varieties of Cymbopogon grasses were evaluated for their repellent properties against the major vector mosquitoes, namely, Anopheles stephensi, Culex quinque-fasciatus and Aedes aegypti, both in laboratory and field. The magnitude of repellency in the Cymbopogon essential oils was found to be of moderate to high order. All grass species protected completely from mosquito bites for 4 hrs, whereas C. nardus provided protection for as much as 8-10 hrs overnight. PMID:23195906

  2. Dynamics of the “Popcorn” Wolbachia Infection in Outbred Aedes aegypti Informs Prospects for Mosquito Vector Control

    PubMed Central

    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.

    2011-01-01

    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

  3. Optimization and synthesis of silver nanoparticles using Isaria fumosorosea against human vector mosquitoes.

    PubMed

    Banu, A Najitha; Balasubramanian, C

    2014-10-01

    The efficacy of silver generated larvicide with the help of entomopathogenic fungi, Isaria fumosorosea (Ifr) against major vector mosquitoes Culex quinquefasciatus and Aedes aegypti. The Ifr-silver nanoparticles (AgNPs) were characterized structurally and functionally using UV-visible spectrophotometer followed by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy and Fourier transform infrared (FTIR) spectra. The optimum pH (alkaline), temperature (30 °C) and agitation (150 rpm) for AgNP synthesis and its stability were confirmed through colour change. Ae. aegypti larvae (I-IV instars) were found highly susceptible to synthesized AgNPs than the larvae of Cx. quinquefasciatus. However, the mortality rate was indirectly proportional to the larval instar and the concentration. The lethal concentration that kills 50% of the exposed larvae (LC50) and lethal concentration that kills 90% of the exposed larvae (LC90) values of the tested concentration are 0.240, 0 0.075.337, 0.430, 0.652 and 1.219, 2.210, 2.453, 2.916; 0.065, 0.075, 0.098, 0.137 and 0.558, 0.709, 0.949, 1.278 ppm with respect to 0.03 to 1.00 ppm of Ifr-AgNPs against first, second, third and fourth instars of Cx. quinquefasciatus and Ae. aegypti, respectively. This is the first report for synthesis of AgNPs using Ifr against human vector mosquitoes. Hence, Ifr-AgNPs would be significantly used as a potent mosquito larvicide. PMID:25085201

  4. Visual arrestins in olfactory pathways of Drosophila and the malaria vector mosquito Anopheles gambiae

    PubMed Central

    Merrill, C. E.; Riesgo-Escovar, J.; Pitts, R. J.; Kafatos, F. C.; Carlson, J. R.; Zwiebel, L. J.

    2002-01-01

    Arrestins are important components for desensitization of G protein-coupled receptor cascades that mediate neurotransmission as well as olfactory and visual sensory reception. We have isolated AgArr1, an arrestin-encoding cDNA from the malaria vector mosquito, Anopheles gambiae, where olfaction is critical for vectorial capacity. Analysis of AgArr1 expression revealed an overlap between chemosensory and photoreceptor neurons. Furthermore, an examination of previously identified arrestins from Drosophila melanogaster exposed similar bimodal expression, and Drosophila arrestin mutants demonstrate impaired electrophysiological responses to olfactory stimuli. Thus, we show that arrestins in Drosophila are required for normal olfactory physiology in addition to their previously described role in visual signaling. These findings suggest that individual arrestins function in both olfactory and visual pathways in Dipteran insects; these genes may prove useful in the design of control strategies that target olfactory-dependent behaviors of insect disease vectors. PMID:11792843

  5. Molecular Characterization of Larval Peripheral Thermosensory Responses of the Malaria Vector Mosquito Anopheles gambiae

    PubMed Central

    Liu, Chao; Zwiebel, Laurence J.

    2013-01-01

    Thermosensation provides vital inputs for the malaria vector mosquito, Anopheles gambiae which utilizes heat-sensitivity within a broad spectrum of behaviors, most notably, the localization of human hosts for blood feeding. In this study, we examine thermosensory behaviors in larval-stage An. gambiae, which as a result of their obligate aquatic habitats and importance for vectorial capacity, represents an opportunistic target for vector control as part of the global campaign to eliminate malaria. As is the case for adults, immature mosquitoes respond differentially to a diverse array of external heat stimuli. In addition, larvae exhibit a striking phenotypic plasticity in thermal-driven behaviors that are established by temperature at which embryonic development occurs. Within this spectrum, RNAi-directed gene-silencing studies provide evidence for the essential role of the Transient Receptor Potential sub-family A1 (TRPA1) channel in mediating larval thermal-induced locomotion and thermal preference within a discrete upper range of ambient temperatures. PMID:23940815

  6. Larvicidal Activity of Cassia occidentalis (Linn.) against the Larvae of Bancroftian Filariasis Vector Mosquito Culex quinquefasciatus

    PubMed Central

    Kumar, Deepak; Chawla, Rakesh; Dhamodaram, P.; Balakrishnan, N.

    2014-01-01

    Background & Objectives. The plan of this work was to study the larvicidal activity of Cassia occidentalis (Linn.) against the larvae of Culex quinquefasciatus. These larvae are the most significant vectors. They transmit the parasites and pathogens which cause a deadly disease like filariasis, dengue, yellow fever, malaria, Japanese encephalitis, chikungunya, and so forth, which are considered harmful towards the population in tropic and subtropical regions. Methods. The preliminary laboratory trail was undertaken to determine the efficacy of petroleum ether and N-butanol extract of dried whole plant of Cassia occidentalis (Linn.) belonging to the family Caesalpiniaceae at various concentrations against the late third instar larvae of Culex quinquefasciatus by following the WHO guidelines. Results. The results suggest that 100% mortality effect of petroleum ether and N-butanol extract of Cassia occidentalis (Linn.) was observed at 200 and 300?ppm (parts per million). The results obviously showed use of plants in insect control as an alternative method for minimizing the noxious effect of some pesticide compounds on the environment. Thus the extract of Cassia occidentalis (Linn.) is claimed as more selective and biodegradable agent. Conclusion. This study justified that plant Cassia occidentalis (Linn.) has a realistic mortality result for larvae of filarial vector. This is safe to individual and communities against mosquitoes. It is a natural weapon for mosquito control. PMID:24688786

  7. Evaluation of a temperate climate mosquito, Ochlerotatus detritus (=Aedes detritus), as a potential vector of Japanese encephalitis virus.

    PubMed

    Mackenzie-Impoinvil, L; Impoinvil, D E; Galbraith, S E; Dillon, R J; Ranson, H; Johnson, N; Fooks, A R; Solomon, T; Baylis, M

    2015-03-01

    The U.K. has not yet experienced a confirmed outbreak of mosquito-borne virus transmission to people or livestock despite numerous autochthonous epizootic and human outbreaks of mosquito-borne diseases on the European mainland. Indeed, whether or not British mosquitoes are competent to transmit arboviruses has not been established. Therefore, the competence of a local (temperate) British mosquito species, Ochlerotatus detritus (=Aedes detritus) (Diptera: Culicidae) for transmission of a member of the genus Flavivirus, Japanese encephalitis virus (JEV) as a model for mosquito-borne virus transmission was assessed. The JEV competence in a laboratory strain of Culex quinquefasciatus (Diptera: Culicidae), a previously incriminated JEV vector, was also evaluated as a positive control. Ochlerotatus detritus adults were reared from field-collected juvenile stages. In oral infection bioassays, adult females developed disseminated infections and were able to transmit virus as determined by the isolation of virus in saliva secretions. When pooled at 7-21?days post-infection, 13% and 25% of O.?detritus were able to transmit JEV when held at 23?°C and 28?°C, respectively. Similar results were obtained for C.?quinquefasciatus. To our knowledge, this study is the first to demonstrate that a British mosquito species, O.?detritus, is a potential vector of an exotic flavivirus. PMID:25087926

  8. Role of gregarine parasite Ascogregarina culicis (Apicomplexa: Lecudinidae) in the maintenance of Chikungunya virus in vector mosquito.

    PubMed

    Moury, D T; Singh, D K; Yadav, P; Gokhale, M D; Barde, P V; Narayan, N B; Thakare, J P; Mishra, A C; Shouche, Y S

    2003-01-01

    Ascogregarina culicis and Ascogregarina taiwanensis are common gregarine parasites of Aedes aegypti and Aedes albopictus mosquitoes, respectively. These mosquito species are also known to transmit dengue and Chikungunya viruses. The sporozoites of these parasites invade the midgut epithelial cells and develop intracellularly and extracellularly in the gut to complete their life cycles. The midgut is also the primary site for virus replication in the vector mosquitoes. Therefore, studies were carried out with a view to determine the possible role of these gregarines in the vertical transmission of dengue and Chikungunya viruses from larval to adult stage. Experiments were performed by exposing first instar mosquito larvae to suspensions containing parasite oocysts and viruses. Since Ascogregarina sporozoites invade the midgut of first instar larvae, the vertical transmission was determined by feeding the uninfected first instar larvae on the freshly prepared homogenates from mosquitoes, which were dually infected with viruses and the parasite oocysts. Similarly, the role of protozoan parasites in the vertical transmission of viruses was determined by exposing fresh first instar larvae to the dried pellets of homogenates prepared from the mosquitoes dually infected with viruses and the parasite oocysts. Direct vertical transmission and the vertical transmission of CHIK virus through the oocyst of the parasites were observed in the case of Ae. aegypti mosquitoes. It is suggested that As. culicis may have an important role in the maintenance of CHIK virus during the inter-epidemic period. PMID:14563178

  9. Using nylon strips to dispense mosquito attractants for sampling the malaria vector Anopheles gambiae s.s.

    PubMed

    Okumu, F; Biswaro, L; Mbeleyela, E; Killeen, G F; Mukabana, R; Moore, S J

    2010-03-01

    Synthetic versions of human derived kairomones can be used as baits when trapping host seeking mosquitoes. The effectiveness of these lures depends not only on their attractiveness to the mosquitoes but also on the medium from which they are dispensed. We report on the development and evaluation of nylon strips as a method of dispensing odorants attractive to the malaria vector, Anopheles gambiae s.s. (Giles). When a synthetic blend of attractants was dispensed using this method, significantly more mosquitoes were trapped than when two previous methods, open glass vials or low density polyethylene sachets were used. We conclude that the nylon strips are suitable for dispensing odorants in mosquito trapping operations and can be adopted for use in rural and remote areas. The nylon material required is cheap and widely available and the strips can be prepared without specialized equipment or electricity. PMID:20380310

  10. Towards a Semen Proteome of the Dengue Vector Mosquito: Protein Identification and Potential Functions

    PubMed Central

    Sirot, Laura K.; Ribeiro, José M. C.; Kimura, Mari; Deewatthanawong, Prasit; Wolfner, Mariana F.; Harrington, Laura C.

    2011-01-01

    Background No commercially licensed vaccine or treatment is available for dengue fever, a potentially lethal infection that impacts millions of lives annually. New tools that target mosquito control may reduce vector populations and break the cycle of dengue transmission. Male mosquito seminal fluid proteins (Sfps) are one such target since these proteins, in aggregate, modulate the reproduction and feeding patterns of the dengue vector, Aedes aegypti. As an initial step in identifying new targets for dengue vector control, we sought to identify the suite of proteins that comprise the Ae. aegypti ejaculate and determine which are transferred to females during mating. Methodology and Principal Findings Using a stable-isotope labeling method coupled with proteomics to distinguish male- and female-derived proteins, we identified Sfps and sperm proteins transferred from males to females. Sfps were distinguished from sperm proteins by comparing the transferred proteins to sperm-enriched samples derived from testes and seminal vesicles. We identified 93 male-derived Sfps and 52 predicted sperm proteins that are transferred to females during mating. The Sfp protein classes we detected suggest roles in protein activation/inactivation, sperm utilization, and ecdysteroidogenesis. We also discovered that several predicted membrane-bound and intracellular proteins are transferred to females in the seminal fluids, supporting the hypothesis that Ae. aegypti Sfps are released from the accessory gland cells through apocrine secretion, as occurs in mammals. Many of the Ae. aegypti predicted sperm proteins were homologous to Drosophila melanogaster sperm proteins, suggesting conservation of their sperm-related function across Diptera. Conclusion and Significance This is the first study to directly identify Sfps transferred from male Ae. aegypti to females. Our data lay the groundwork for future functional analyses to identify individual seminal proteins that may trigger female post-mating changes (e.g., in feeding patterns and egg production). Therefore, identification of these proteins may lead to new approaches for manipulating the reproductive output and vectorial capacity of Ae. aegypti. PMID:21423647

  11. Persistent Wolbachia and Cultivable Bacteria Infection in the Reproductive and Somatic Tissues of the Mosquito Vector Aedes albopictus

    Microsoft Academic Search

    Karima Zouache; Denis Voronin; Van Tran-van; Laurence Mousson; Anna-Bella Failloux; Patrick Mavingui; Niyaz Ahmed

    2009-01-01

    BackgroundCommensal and symbiotic microbes have a considerable impact on the behavior of many arthropod hosts, including hematophagous species that transmit pathogens causing infectious diseases to human and animals. Little is known about the bacteria associated with mosquitoes other than the vectorized pathogens. This study investigated Wolbachia and cultivable bacteria that persist through generations in Ae. albopictus organs known to host

  12. piRNA pathway gene expression in the malaria vector mosquito Anopheles stephensi.

    PubMed

    Macias, V; Coleman, J; Bonizzoni, M; James, A A

    2014-10-01

    The ability of transposons to mobilize to new places in a genome enables them to introgress rapidly into populations. The piRNA pathway has been characterized recently in the germ line of the fruit fly, Drosophila melanogaster, and is responsible for downregulating transposon mobility. Transposons have been used as tools in mosquitoes to genetically transform a number of species including Anopheles stephensi, a vector of human malaria. These mobile genetic elements also have been proposed as tools to drive antipathogen effector genes into wild mosquito populations to replace pathogen-susceptible insects with those engineered genetically to be resistant to or unable to transmit a pathogen. The piRNA pathway may affect the performance of such proposed genetic engineering strategies. In the present study, we identify and describe the An. stephensi orthologues of the major genes in the piRNA pathway, Ago3, Aubergine (Aub) and Piwi. Consistent with a role in protection from transposon movement, these three genes are expressed constitutively in the germ-line cells of ovaries and induced further after a blood meal. PMID:24947897

  13. Artificial activation of mature unfertilized eggs in the malaria vector mosquito, Anopheles stephensi (Diptera, Culicidae).

    PubMed

    Yamamoto, Daisuke S; Hatakeyama, Masatsugu; Matsuoka, Hiroyuki

    2013-08-01

    In the past decade, many transgenic lines of mosquitoes have been generated and analyzed, whereas the maintenance of a large number of transgenic lines requires a great deal of effort and cost. In vitro fertilization by an injection of cryopreserved sperm into eggs has been proven to be effective for the maintenance of strains in mammals. The technique of artificial egg activation is a prerequisite for the establishment of in vitro fertilization by sperm injection. We demonstrated that artificial egg activation is feasible in the malaria vector mosquito, Anopheles stephensi (Diptera, Culicidae). Nearly 100% of eggs dissected from virgin females immersed in distilled water darkened, similar to normally oviposited fertilized eggs. It was revealed by the cytological examination of chromosomes that meiotic arrest was relieved in these eggs approximately 20 min after incubation in water. Biochemical examinations revealed that MAPK (mitogen-activated protein kinase)/ERK (extracellular signal-regulated protein kinase) and MEK (MAPK/ERK kinase) were dephosphorylated similar to that in fertilized eggs. These results indicate that dissected unfertilized eggs were activated in distilled water and started development. Injection of distilled water into body cavity of the virgin blood-fed females also induced activation of a portion of eggs in the ovaries. The technique of artificial egg activation is expected to contribute to the success of in vitro fertilization in A. stephensi. PMID:23619405

  14. Vector ability of mosquitoes for isolates of Plasmodium elongatum from raptors in Florida.

    PubMed

    Nayar, J K; Knight, J W; Telford, S R

    1998-06-01

    Three isolates of Plasmodium elongatum were obtained from 3 species of raptors (red-tailed hawk [Buteo jamaicensis], bald eagle [Haliaeetus leucocephalus], and eastern screech owl [Otus asio]) from Florida using isodiagnostic techniques in Pekin ducks (Anas platyrhynchos). Six to 10 species of mosquitoes were tested for susceptibility to these 3 isolates. Complete development of the sporogonic cycle of the 3 isolates of P. elongatum occurred in 3 species of mosquitoes, Culex nigripalpus, Culex restuans, and Culex salinarius. The pattern of susceptibility was similar among the 3 isolates of P. elongatum in Cx. nigripalpus. Culex restuans and Cx. salinarius were significantly more susceptible than Cx. nigripalpus to the 3 isolates of P. elongatum tested. Culex nigripalpus transmitted all 3 isolates of P. elongatum from duck to duck both by bite and after intraperitoneal injection of sporozoites. Infections of the 2 isolates tested occurred in ducks after intraperitoneal injection of sporozoites from Cx. restuans and Cx. salinarius. The results suggest that these 3 Culex species are potential vectors of P. elongatum from raptors in Florida. PMID:9645854

  15. piRNA pathway gene expression in the malaria vector mosquito Anopheles stephensi

    PubMed Central

    Macias, V; Coleman, J; Bonizzoni, M; James, A A

    2014-01-01

    The ability of transposons to mobilize to new places in a genome enables them to introgress rapidly into populations. The piRNA pathway has been characterized recently in the germ line of the fruit fly, Drosophila melanogaster, and is responsible for downregulating transposon mobility. Transposons have been used as tools in mosquitoes to genetically transform a number of species including Anopheles stephensi, a vector of human malaria. These mobile genetic elements also have been proposed as tools to drive antipathogen effector genes into wild mosquito populations to replace pathogen-susceptible insects with those engineered genetically to be resistant to or unable to transmit a pathogen. The piRNA pathway may affect the performance of such proposed genetic engineering strategies. In the present study, we identify and describe the An. stephensi orthologues of the major genes in the piRNA pathway, Ago3, Aubergine (Aub) and Piwi. Consistent with a role in protection from transposon movement, these three genes are expressed constitutively in the germ-line cells of ovaries and induced further after a blood meal. PMID:24947897

  16. Identification of wild collected mosquito vectors of diseases using gas chromatography-mass spectrometry in Jazan Province, Saudi Arabia.

    PubMed

    Al Ahmed, Azzam M; Badjah-Hadj-Ahmed, Ahmed-Yacine; Al Othman, Zeid A; Sallam, Mohamed F

    2013-11-01

    Thirty-three species of mosquitoes have been reported from the Kingdom of Saudi Arabia. Several of these mosquitoes, Anopheles gambiae Giles s.l., Anopheles stephensi Liston, Culex pipiens Linnaeus, Culex quinquefasciatus Say, Culex tritaeniorhynchus Giles, Stegomyia aegypti (Linnaeus) and Aedimorphus vexans arabiensis (Patton) are known vectors of human and animal diseases. In this study, the cuticular hydrocarbon profiles of eight mosquito species using gas chromatography-mass spectrometry were analyzed. Wild collected fourth-instar larvae were reared, and single, newly emerged, unfed adult females were used for the analysis. A total of 146-160 peaks were detected from the cuticular extracts by gas chromatography. Repeated analysis of variance (ANOVA) and Tukey HSD Post Hoc test was used to test for quantitative differences in relative hydrocarbon quantity. In addition, a linear regression model was applied using Enter method to determine the diagnostic peaks for the eight mosquito specimens. The ANOVA test indicated that relative peaks were significant (P < 0.05) when selected pairs of peaks were compared. Also, seven compounds showed qualitative differences among the five mosquito vectors tested. The classes of constituents present were n-alkanes, monomethylalkanes, dimethylalkanes, trimethylalkanes, alkenes, branched aromatic hydrocarbons, aldehydes and esters. These compounds have a carbon chain length ranging from 8 to 18 carbons. The most abundant compound in all adult mosquito specimens was n-hexylacrylate [retention time (RT) 6.73 min], which was not detected in Cx. pipiens. In Cx. pipiens, the most abundant peak was benzaldehyde (RT 2.98 min). Gas chromatography-mass spectrometry is a suitable method to identify adult mosquitoes, especially from focal areas of public health concern such as Jazan Province, Saudi Arabia. This method allows a wide range of adult collected material to be identified with high accuracy. PMID:24259205

  17. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

    PubMed Central

    Mweya, Clement N.; Kimera, Sharadhuli I.; Mellau, Lesakit S. B.; Mboera, Leonard E. G.

    2015-01-01

    Background Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC) light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results A total of 1,823 mosquitoes were collected, of which 87% (N=1,588) were Culex pipiens complex, 12% (N=226) Aedes aegypti, and 0.5% (N=9) Anopheles species. About two-thirds (67%; N=1,095) of C. pipiens complex and nearly 100% (N=225) of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78%) of C. pipiens complex and most (85%) of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania. PMID:25613346

  18. Chikungunya virus and the mosquito vector Aedes aegypti in New Caledonia (South Pacific Region).

    PubMed

    Dupont-Rouzeyrol, Myrielle; Caro, Valérie; Guillaumot, Laurent; Vazeille, Marie; D'Ortenzio, Eric; Thiberge, Jean-Michel; Baroux, Noémie; Gourinat, Ann-Claire; Grandadam, Marc; Failloux, Anna-Bella

    2012-12-01

    Chikungunya virus (CHIKV) is transmitted to humans through the bite of Aedes mosquitoes. During the 2005-2006 epidemic that occurred in the Indian Ocean Islands, a viral strain harboring a substitution of an alanine to valine at position 226 (E1-A226V) of the E1 glycoprotein enhanced the transmissibility of CHIKV by Aedes albopictus. In March 2011, autochthonous transmission of CHIKV was reported in New Caledonia (NC), an island located in the southwest Pacific Ocean. This was the first report of local chikungunya (CHIK) transmission in this region of the world. Phylogenetic analysis based on the complete genome demonstrated that the CHIKV-NC strain isolated from the first autochthonous human case belongs to the Asian lineage. This is consistent with the Indonesian origin of CHIK cases previously imported and detected. Thus the CHIKV-NC does not present a valine substitution at position E1-226. In New Caledonia, the putative vector of CHIKV is Aedes aegypti, since no other potential vector has ever been described. For example, A. albopictus is not found in NC. Vector competence experiments showed that A. aegypti from New Caledonia was able to transmit, as early as 3 days post-infection, two CHIKV strains: CHIKV-NC belonging to the Asian lineage, and CHIKV-RE from Reunion Island harboring the E1-A226V mutation. Thus the extrinsic incubation period of both CHIKV strains in this vector species could be considered to be quite short. These results illustrate the threat of the spread of CHIKV in the South Pacific region. From February to June 2011 (the end of the alert), only 33 cases were detected. Implementation of drastic vector control measures and the occurrence of the cold season probably helped to limit the extent of the outbreak, but other factors may have also been involved and are discussed. PMID:23167500

  19. A generic model for a single strain mosquito-transmitted disease with memory on the host and the vector.

    PubMed

    Sardar, Tridip; Rana, Sourav; Bhattacharya, Sabyasachi; Al-Khaled, Kamel; Chattopadhyay, Joydev

    2015-05-01

    In the present investigation, three mathematical models on a common single strain mosquito-transmitted diseases are considered. The first one is based on ordinary differential equations, and other two models are based on fractional order differential equations. The proposed models are validated using published monthly dengue incidence data from two provinces of Venezuela during the period 1999-2002. We estimate several parameters of these models like the order of the fractional derivatives (in case of two fractional order systems), the biting rate of mosquito, two probabilities of infection, mosquito recruitment and mortality rates, etc., from the data. The basic reproduction number, R0, for the ODE system is estimated using the data. For two fractional order systems, an upper bound for, R0, is derived and its value is obtained using the published data. The force of infection, and the effective reproduction number, R(t), for the three models are estimated using the data. Sensitivity analysis of the mosquito memory parameter with some important responses is worked out. We use Akaike Information Criterion (AIC) to identify the best model among the three proposed models. It is observed that the model with memory in both the host, and the vector population provides a better agreement with epidemic data. Finally, we provide a control strategy for the vector-borne disease, dengue, using the memory of the host, and the vector. PMID:25645185

  20. Evaluation of Hexane Extract of Tuber of Root of Cyperus rotundus Linn (Cyperaceae) for Repellency against Mosquito Vectors

    PubMed Central

    Singh, S. P.; Raghavendra, K.; Dash, A. P.

    2009-01-01

    Hexane extract of tuber of plant Cyperus rotundus (Cyperaceae) was screened under laboratory conditions for repellent activity against mosquito vector Anopheles culicifacies Giles species A (Diptera: Culicidae), Anopheles stephensi Liston (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae). The Cyperus rotundus tuber extract was used to determine their effect on mosquito vector, and comparison with the DEET (NN Diethyl 1-3 methyl Benzamide, formerly known as diethyl 1-m-toluamide). The tuber extracts showed more effective at all the dose. Result obtained from the laboratory experiment showed that the tuber extracts are more effective for repellency of allthe mosquito vector even at low dose. Clear dose response relationships were established with the highest dose of 10% tuber extract evoking 100% repellency. Percent protection obtained against An. culicifacies Giles species A 100% repellency in 4 hours, 6 hours, An. stephensi 100% repellency in 6 hours and Cx. quinquefasciatus was 100% repellency in 6 hours at the 10% concentration. Against DEET- 2.5% An. culicifacies A 100% repellency in 1 hour, 2 hours, 6 hours, An. stephensi have shown 100% repellency in 6 hours, and Culex quinquefasciatus have shown 100% repellency in 1 hour, 2 hours, 6 hours. The consolidated data of the repellency observed in different species is given and it is evident that the over all repellency rates varied between 80 and 100% for different repellents concentrations (2.5%, 5%, and 10%). The extract can be applied as an effective personal protective measure against mosquito bites. PMID:20798887

  1. Evaluation of Hexane Extract of Tuber of Root of Cyperus rotundus Linn (Cyperaceae) for Repellency against Mosquito Vectors.

    PubMed

    Singh, S P; Raghavendra, K; Dash, A P

    2009-01-01

    Hexane extract of tuber of plant Cyperus rotundus (Cyperaceae) was screened under laboratory conditions for repellent activity against mosquito vector Anopheles culicifacies Giles species A (Diptera: Culicidae), Anopheles stephensi Liston (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae). The Cyperus rotundus tuber extract was used to determine their effect on mosquito vector, and comparison with the DEET (NN Diethyl 1-3 methyl Benzamide, formerly known as diethyl 1-m-toluamide). The tuber extracts showed more effective at all the dose. Result obtained from the laboratory experiment showed that the tuber extracts are more effective for repellency of allthe mosquito vector even at low dose. Clear dose response relationships were established with the highest dose of 10% tuber extract evoking 100% repellency. Percent protection obtained against An. culicifacies Giles species A 100% repellency in 4 hours, 6 hours, An. stephensi 100% repellency in 6 hours and Cx. quinquefasciatus was 100% repellency in 6 hours at the 10% concentration. Against DEET- 2.5% An. culicifacies A 100% repellency in 1 hour, 2 hours, 6 hours, An. stephensi have shown 100% repellency in 6 hours, and Culex quinquefasciatus have shown 100% repellency in 1 hour, 2 hours, 6 hours. The consolidated data of the repellency observed in different species is given and it is evident that the over all repellency rates varied between 80 and 100% for different repellents concentrations (2.5%, 5%, and 10%). The extract can be applied as an effective personal protective measure against mosquito bites. PMID:20798887

  2. Host-Feeding Patterns of Potential Mosquito Vectors in Connecticut, USA: Molecular Analysis of Bloodmeals from 23 Species of Aedes , Anopheles , Culex , Coquillettidia , Psorophora , and Uranotaenia

    Microsoft Academic Search

    Goudarz Molaei; Theodore G. Andreadis; Philip M. Armstrong; Maria Diuk-Wasser

    2008-01-01

    We evaluated the blood-feeding patterns in several mosquito species that may serve as vectors of disease agents in the northeastern United States. Blood-fed mosquitoes were collected from 91 different sites throughout Connecticut over a 6-yr period (JuneÐOctober 2002Ð2007), and the host-feeding patterns of 23 mosquito species representing six genera were examined by using a polymerase chain reaction-based assay and sequencing

  3. Present and future projections of habitat suitability of the Asian tiger mosquito, a vector of viral pathogens, from global climate simulation.

    PubMed

    Proestos, Y; Christophides, G K; Ergüler, K; Tanarhte, M; Waldock, J; Lelieveld, J

    2015-04-01

    Climate change can influence the transmission of vector-borne diseases (VBDs) through altering the habitat suitability of insect vectors. Here we present global climate model simulations and evaluate the associated uncertainties in view of the main meteorological factors that may affect the distribution of the Asian tiger mosquito (Aedes albopictus), which can transmit pathogens that cause chikungunya, dengue fever, yellow fever and various encephalitides. Using a general circulation model at 50 km horizontal resolution to simulate mosquito survival variables including temperature, precipitation and relative humidity, we present both global and regional projections of the habitat suitability up to the middle of the twenty-first century. The model resolution of 50 km allows evaluation against previous projections for Europe and provides a basis for comparative analyses with other regions. Model uncertainties and performance are addressed in light of the recent CMIP5 ensemble climate model simulations for the RCP8.5 concentration pathway and using meteorological re-analysis data (ERA-Interim/ECMWF) for the recent past. Uncertainty ranges associated with the thresholds of meteorological variables that may affect the distribution of Ae. albopictus are diagnosed using fuzzy-logic methodology, notably to assess the influence of selected meteorological criteria and combinations of criteria that influence mosquito habitat suitability. From the climate projections for 2050, and adopting a habitat suitability index larger than 70%, we estimate that approximately 2.4 billion individuals in a land area of nearly 20 million km(2) will potentially be exposed to Ae. albopictus. The synthesis of fuzzy-logic based on mosquito biology and climate change analysis provides new insights into the regional and global spreading of VBDs to support disease control and policy making. PMID:25688015

  4. Present and Future Projections of Habitat Suitability of the Asian Tiger Mosquito, a Vector of Viral Pathogens, from Global Climate Simulations.

    NASA Astrophysics Data System (ADS)

    Proestos, Y.; Christophides, G.; Erguler, K.; Tanarhte, M.; Waldock, J.; Lelieveld, J.

    2014-12-01

    Climate change can influence the transmission of vector borne diseases (VBDs) through altering the habitat suitability of insect vectors. Here we present global climate model simulations and evaluate the associated uncertainties in view of the main meteorological factors that may affect the distribution of the Asian Tiger mosquito (Aedes albopictus), which can transmit pathogens that cause Chikungunya, Dengue fever, yellow fever and various encephalitides. Using a general circulation model (GCM) at 50 km horizontal resolution to simulate mosquito survival variables including temperature, precipitation and relative humidity, we present both global and regional projections of the habitat suitability up to the middle of the 21st century. The model resolution of 50 km allows evaluation against previous projections for Europe and provides a basis for comparative analyses with other regions. Model uncertainties and performance are addressed in light of the recent CMIP5 ensemble climate model simulations for the RCP8.5 concentration pathway and using meteorological re-analysis data (ERA-Interim/ECMWF) for the recent past. Uncertainty ranges associated with the thresholds of meteorological variables that may affect the distribution of Ae. albopictus are diagnosed using fuzzy-logic methodology, notably to assess the influence of selected meteorological criteria and combinations of criteria that influence mosquito habitat suitability. From the climate projections for 2050, and adopting a habitat suitability index larger than 70%, we estimate that about 2.4 billion individuals in a land area of nearly 20 million square kilometres will potentially be exposed to Ae. albopictus. The synthesis of fuzzy-logic based on mosquito biology and climate change analysis provides new insights into the regional and global spreading of VBDs to support disease control and policy making.

  5. Venezuelan equine encephalitis virus in the mosquito vector Aedes taeniorhynchus: Infection initiated by a small number of susceptible epithelial cells and a population bottleneck

    Microsoft Academic Search

    Darci R. Smith; A. Paige Adams; Joan L. Kenney; Eryu Wang; Scott C. Weaver

    2008-01-01

    We evaluated infection of Aedes taeniorhynchus mosquitoes, vectors of Venezuelan equine encephalitis virus (VEEV), using radiolabeled virus and replicon particles expressing green (GFP) or cherry fluorescent protein (CFP). More epidemic VEEV bound to and infected mosquito midguts compared to an enzootic strain, and a small number of midgut cells was preferentially infected. Chimeric replicons infected midgut cells at rates comparable

  6. Larvicidal activity of Saraca indica, Nyctanthes arbor-tristis, and Clitoria ternatea extracts against three mosquito vector species.

    PubMed

    Mathew, Nisha; Anitha, M G; Bala, T S L; Sivakumar, S M; Narmadha, R; Kalyanasundaram, M

    2009-04-01

    Screening of natural products for mosquito larvicidal activity against three major mosquito vectors Aedes aegypti, Culex quinquefasciatus, and Anopheles stephensi resulted in the identification of three potential plant extracts viz., Saraca indica/asoca, Nyctanthes arbor-tristis, and Clitoria ternatea for mosquito larval control. In the case of S. indica/asoca, the petroleum ether extract of the leaves and the chloroform extract of the bark were effective against the larvae of C. quinquefasciatus with respective LC(50) values 228.9 and 291.5 ppm. The LC(50) values of chloroform extract of N. arbor-tristis leaves were 303.2, 518.2, and 420.2 ppm against A. aegypti, A. stephensi, and C. quinquefasciatus, respectively. The methanol and chloroform extracts of flowers of N. arbor-tristis showed larvicidal activity against larvae of A. stephensi with the respective LC(50) values of 244.4 and 747.7 ppm. Among the methanol extracts of C. ternatea leaves, roots, flowers, and seeds, the seed extract was effective against the larvae of all the three species with LC(50) values 65.2, 154.5, and 54.4 ppm, respectively, for A. stephensi, A. aegypti, and C. quinquefasciatus. Among the three plant species studied for mosquito larvicidal activity, C. ternatea was showing the most promising mosquito larvicidal activity. The phytochemical analysis of the promising methanolic extract of the seed extract was positive for carbohydrates, saponins, terpenoids, tannins, and proteins. In conclusion, bioassay-guided fractionation of effective extracts may result in identification of a useful molecule for the control of mosquito vectors. PMID:19039604

  7. Aromatic plant-derived essential oil: An alternative larvicide for mosquito control

    Microsoft Academic Search

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

    2007-01-01

    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

  8. Comparative analysis of midgut bacterial communities of Aedes aegypti mosquito strains varying in vector competence to dengue virus.

    PubMed

    Charan, Shakti S; Pawar, Kiran D; Severson, David W; Patole, Milind S; Shouche, Yogesh S

    2013-07-01

    Differences in midgut bacterial communities of Aedes aegypti, the primary mosquito vector of dengue viruses (DENV), might influence the susceptibility of these mosquitoes to infection by DENV. As a first step toward addressing this hypothesis, comparative analysis of bacterial communities from midguts of mosquito strains with differential genetic susceptibility to DENV was performed. 16S rRNA gene libraries and real-time PCR approaches were used to characterize midgut bacterial community composition and abundance in three Aedes aegypti strains: MOYO, MOYO-R, and MOYO-S. Although Pseudomonas spp.-related clones were predominant across all libraries, some interesting and potentially significant differences were found in midgut bacterial communities among the three strains. Pedobacter sp.- and Janthinobacterium sp.-related phylotypes were identified only in the MOYO-R strain libraries, while Bacillus sp. was detected only in the MOYO-S strain. Rahnella sp. was found in MOYO-R and MOYO strains libraries but was absent in MOYO-S libraries. Both 16S rRNA gene library and real-time PCR approaches confirmed the presence of Pedobacter sp. only in the MOYO-R strain. Further, real-time PCR-based quantification of 16S rRNA gene copies showed bacterial abundance in midguts of the MOYO-R strain mosquitoes to be at least 10-100-folds higher than in the MOYO-S and MOYO strain mosquitoes. Our study identified some putative bacteria with characteristic physiological properties that could affect the infectivity of dengue virus. This analysis represents the first report of comparisons of midgut bacterial communities with respect to refractoriness and susceptibility of Aedes aegypti mosquitoes to DENV and will guide future efforts to address the potential interactive role of midgut bacteria of Aedes aegypti mosquitoes in determining vectorial capacity for DENV. PMID:23636307

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

    PubMed Central

    2011-01-01

    Background Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito Aedes aegypti (Diptera, Culicidae), a vector of Dengue viruses, Yellow Fever Virus (YFV) and Chikungunya virus (CV), is the subject of this study to look at genome-wide changes in gene expression following a blood meal. Results Transcriptional changes that follow a blood meal in Ae. aegypti females were explored using RNA-seq technology. Over 30% of more than 18,000 investigated transcripts accumulate differentially in mosquitoes at five hours after a blood meal when compared to those fed only on sugar. Forty transcripts accumulate only in blood-fed mosquitoes. The list of regulated transcripts correlates with an enhancement of digestive activity and a suppression of environmental stimuli perception and innate immunity. The alignment of more than 65 million high-quality short reads to the Ae. aegypti reference genome permitted the refinement of the current annotation of transcript boundaries, as well as the discovery of novel transcripts, exons and splicing variants. Cis-regulatory elements (CRE) and cis-regulatory modules (CRM) enriched significantly at the 5'end flanking sequences of blood meal-regulated genes were identified. Conclusions This study provides the first global view of the changes in transcript accumulation elicited by a blood meal in Ae. aegypti females. This information permitted the identification of classes of potentially co-regulated genes and a description of biochemical and physiological events that occur immediately after blood feeding. The data presented here serve as a basis for novel vector control and pathogen transmission-blocking strategies including those in which the vectors are modified genetically to express anti-pathogen effector molecules. PMID:21276245

  10. Distribution of the main malaria vectors in Kenya

    PubMed Central

    2010-01-01

    Background A detailed knowledge of the distribution of the main Anopheles malaria vectors in Kenya should guide national vector control strategies. However, contemporary spatial distributions of the locally dominant Anopheles vectors including Anopheles gambiae, Anopheles arabiensis, Anopheles merus, Anopheles funestus, Anopheles pharoensis and Anopheles nili are lacking. The methods and approaches used to assemble contemporary available data on the present distribution of the dominant malaria vectors in Kenya are presented here. Method Primary empirical data from published and unpublished sources were identified for the period 1990 to 2009. Details recorded for each source included the first author, year of publication, report type, survey location name, month and year of survey, the main Anopheles species reported as present and the sampling and identification methods used. Survey locations were geo-positioned using national digital place name archives and on-line geo-referencing resources. The geo-located species-presence data were displayed and described administratively, using first-level administrative units (province), and biologically, based on the predicted spatial margins of Plasmodium falciparum transmission intensity in Kenya for the year 2009. Each geo-located survey site was assigned an urban or rural classification and attributed an altitude value. Results A total of 498 spatially unique descriptions of Anopheles vector species across Kenya sampled between 1990 and 2009 were identified, 53% were obtained from published sources and further communications with authors. More than half (54%) of the sites surveyed were investigated since 2005. A total of 174 sites reported the presence of An. gambiae complex without identification of sibling species. Anopheles arabiensis and An. funestus were the most widely reported at 244 and 265 spatially unique sites respectively with the former showing the most ubiquitous distribution nationally. Anopheles gambiae, An. arabiensis, An. funestus and An. pharoensis were reported at sites located in all the transmission intensity classes with more reports of An. gambiae in the highest transmission intensity areas than the very low transmission areas. Conclusion A contemporary, spatially defined database of the main malaria vectors in Kenya provides a baseline for future compilations of data and helps identify areas where information is currently lacking. The data collated here are published alongside this paper where it may help guide future sampling location decisions, help with the planning of vector control suites nationally and encourage broader research inquiry into vector species niche modeling. PMID:20202199

  11. Adulticidal properties of synthesized silver nanoparticles using leaf extracts of Feronia elephantum (Rutaceae) against filariasis, malaria, and dengue vector mosquitoes.

    PubMed

    Veerakumar, Kaliyan; Govindarajan, Marimuthu

    2014-11-01

    Mosquito-borne diseases with an economic impact create loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Extracts from plants may be alternative sources of mosquito control agents because they constitute a rich source of bioactive compounds that are biodegradable into nontoxic products and potentially suitable for use to control mosquitoes. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Feronia elephantum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. The range of concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 ?g mL(-1)) and aqueous leaf extract (40, 80, 120, 160, and 200 ?g mL(-1)) were tested against the adults of A. stephensi, A. aegypti, and C. quinquefasciatus. Adults were exposed to varying concentrations of aqueous crude extract and synthesized AgNPs for 24 h. Considerable mortality was evident after the treatment of F. elephantum for all three important vector mosquitoes. The synthesized AgNPs from F. elephantum were highly toxic than crude leaf aqueous extract to three important vector mosquito species. The results were recorded from UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy analysis (EDX), and transmission electron microscopy (TEM). Synthesized AgNPs against the vector mosquitoes A. stephensi, A. aegypti, and C. quinquefasciatus had the following lethal dose (LD)?? and LD?? values: A. stephensi had LD?? and LD?? values of 18.041 and 32.575 ?g mL(-1); A. aegypti had LD?? and LD?? values of 20.399 and 37.534 ?g mL(-1); and C. quinquefasciatus had LD?? and LD?? values of 21.798 and 39.596 ?g mL(-1). No mortality was observed in the control. These results suggest that the leaf aqueous extracts of F. elephantum and green synthesis of AgNPs have the potential to be used as an ideal eco-friendly approach for the control of the A. stephensi, A. aegypti, and C. quinquefasciatus. This is the first report on the adulticidal activity of the plant extracts and AgNPs. PMID:25146645

  12. Field trials on the efficacy of DEET-impregnated anklets, wristbands, shoulder, and pocket strips against mosquito vectors of disease.

    PubMed

    Karunamoorthi, Kaliyaperumal; Sabesan, Shanmugavelu

    2009-09-01

    A field trial was undertaken in order to determine the efficacy of DEET (N,N-diethyl-m-toluamide) impregnated anklets, wristbands, shoulder and pocket fabric strips against mosquito vectors of disease. The present study was conducted in the urban locality of Pondicherry, India. Human test subjects were exposed to natural populations of mosquitoes for a 12 h (18.00-06.00) night time period. The fabric strips (anklets, wristbands, shoulder, and pocket strips) were impregnated with DEET at two different concentrations of 1.5 mg/cm(2) and 2.0 mg/cm(2). The results clearly revealed that DEET-impregnated anklets, wristbands, shoulder and pocket fabric strips were found more effective against mosquitoes remarkably. The DEET-impregnated anklets, wristbands, shoulder and pocket fabric strips at a concentration of 2 mg/cm(2) provided 5 h complete protection against mosquitoes bites and the reduction of man-landing rate varied between 65.85 and 100%. However, DEET-impregnated fabric strips at a concentration of 1.5 mg/cm(2) provided 4 h complete protection against mosquito bites and the reduction of man-landing rate varied between 51.21 and 100%. The final results clearly demonstrate that repellent activity of DEET-impregnated anklets, wristbands, shoulder, and pocket strips were dose-dependent. Certainly, the DEET-impregnated fabric strips can be used as an effective potential personal protection measure in order to avoid those insects/mosquitoes that prefer to feed outdoors or those that feed in the early evening. PMID:19352705

  13. An Integrated Genetic Map of the African Human Malaria Vector Mosquito, Anopheles Gambiae

    PubMed Central

    Zheng, L.; Benedict, M. Q.; Cornel, A. J.; Collins, F. H.; Kafatos, F. C.

    1996-01-01

    We present a genetic map based on microsatellite polymorphisms for the African human malaria vector, Anopheles gambiae. Polymorphisms in laboratory strains were detected for 89% of the tested microsatellite markers. Genotyping was performed for individual mosquitoes from 13 backcross families that included 679 progeny. Three linkage groups were identified, corresponding to the three chromosomes. We added 22 new markers to the existing X chromosome map, for a total of 46 microsatellite markers spanning a distance of 48.9 cM. The second chromosome has 57 and the third 28 microsatellite markers spanning a distance of 72.4 and 93.7 cM, respectively. The overall average distance between markers is 1.6 cM (or 1.1, 1.2, and 3.2 cM for the X, second, and third chromosomes, respectively). In addition to the 131 microsatellite markers, the current map also includes a biochemical selectable marker, Dieldrin resistance (Dl), on the second chromosome and five visible markers, pink-eye (p) and white (w) on the X, collarless (c) and lunate (lu) on the second, and red-eye (r) on the third. The cytogenetic locations on the nurse cell polytene chromosomes have been determined for 47 markers, making this map an integrated tool for cytogenetic, genetic, and molecular analysis. PMID:8725240

  14. Mosquito Life Cycle

    NSDL National Science Digital Library

    2013-07-30

    In this activity, learners build a plastic emergence chamber (or use purchased "mini mosquito breeder") to observe and analyze the mosquito life cycle. Learners record daily observations for 8-14 days by counting the number of larvae, pupae, and adults present in the chamber. This resource includes background information about the mosquito life cycle and mosquitoes as disease vectors plus a link to a mosquito reference manual.

  15. Persistent Wolbachia and Cultivable Bacteria Infection in the Reproductive and Somatic Tissues of the Mosquito Vector Aedes albopictus

    PubMed Central

    Zouache, Karima; Voronin, Denis; Tran-Van, Van; Mousson, Laurence; Failloux, Anna-Bella; Mavingui, Patrick

    2009-01-01

    Background Commensal and symbiotic microbes have a considerable impact on the behavior of many arthropod hosts, including hematophagous species that transmit pathogens causing infectious diseases to human and animals. Little is known about the bacteria associated with mosquitoes other than the vectorized pathogens. This study investigated Wolbachia and cultivable bacteria that persist through generations in Ae. albopictus organs known to host transmitted arboviruses, such as dengue and chikungunya. Methodology/Principal Findings We used culturing, diagnostic and quantitative PCR, as well as in situ hybridization, to detect and locate bacteria in whole individual mosquitoes and in dissected tissues. Wolbachia, cultivable bacteria of the genera Acinetobacter, Comamonas, Delftia and Pseudomonas co-occurred and persisted in the bodies of both males and females of Ae. albopictus initially collected in La Réunion during the chikungunya outbreak, and maintained as colonies in insectaries. In dissected tissues, Wolbachia and the cultivable Acinetobacter can be detected in the salivary glands. The other bacteria are commonly found in the gut. Quantitative PCR estimates suggest that Wolbachia densities are highest in ovaries, lower than those of Acinetobacter in the gut, and approximately equal to those of Acinetobacter in the salivary glands. Hybridization using specific fluorescent probes successfully localized Wolbachia in all germ cells, including the oocytes, and in the salivary glands, whereas the Acinetobacter hybridizing signal was mostly located in the foregut and in the anterior midgut. Conclusions/Significance Our results show that Proteobacteria are distributed in the somatic and reproductive tissues of mosquito where transmissible pathogens reside and replicate. This location may portend the coexistence of symbionts and pathogens, and thus the possibility that competition or cooperation phenomena may occur in the mosquito vector Ae. albopictus. Improved understanding of the vectorial system, including the role of bacteria in the vector's biology and competence, could have major implications for understanding viral emergences and for disease control. PMID:19633721

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

    PubMed Central

    Chowdhury, Nandita; Ghosh, Anupam; Chandra, Goutam

    2008-01-01

    Background 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. Although several plants have been reported for mosquitocidal activity, only a few botanicals have moved from the laboratory to field use, because they are poorly characterized, in most cases active principals are not determined and most of the works are restricted to preliminary screening. Solanum villosum is a common weed distributed in many parts of India with medicinal properties, but the larvicidal activity of this plant has not been reported so far. Methods Aqueous and polar/non-polar solvent extract of fresh, mature, green berries of S. villosum was tested against Stegomyia aegypti, a common vector of dengue fever. A phytochemical analysis of chloroform:methanol extract was performed to search for the active toxic ingredient. The lethal concentration was determined (log probit analysis) and compared with Malathion. The chemical nature of the active substance was also evaluated following ultraviolet-visual (UV-Vis) and infrared (IR) analysis. Results In a 72 hour bioassay experiment with the aqueous extract, the highest mortality was recorded in 0.5% extract. When the mortality of different solvent extracts was compared, the maximum (p < 0.05) mortality was recorded at a concentration of 50 ppm of chloroform:methanol extract (1:1, v/v). The larvicidal activity was lower when compared with the chemical insecticide, Malathion (p < 0.05). Results of regression analysis revealed that the mortality rate (Y) was positively correlated with the period of exposure (X) and the log probit analysis (95% confidence level) recorded lowest value (5.97 ppm) at 72 hours of exposure. Phytochemical analysis of the chlororm:methanol extract reported the presence of many bioactive phytochemicals. Two toxic compounds were detected having Rf = 0.82 (70% and 73.33% mortality in 24 and 48 hours, respectively) and Rf = 0.95 (40% and 50% mortality in 24 and 48 hours, respectively). IR analysis provided preliminary information about the steroidal nature of the active ingredient. Conclusion S. villosum offers promise as 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. PMID:18387176

  17. Sialic Acid Expression in the Mosquito Aedes aegypti and Its Possible Role in Dengue Virus-Vector Interactions.

    PubMed

    Cime-Castillo, Jorge; Delannoy, Philippe; Mendoza-Hernández, Guillermo; Monroy-Martínez, Verónica; Harduin-Lepers, Anne; Lanz-Mendoza, Humberto; Hernández-Hernández, Fidel de la Cruz; Zenteno, Edgar; Cabello-Gutiérrez, Carlos; Ruiz-Ordaz, Blanca H

    2015-01-01

    Dengue fever (DF) is the most prevalent arthropod-borne viral disease which affects humans. DF is caused by the four dengue virus (DENV) serotypes, which are transmitted to the host by the mosquito Aedes aegypti that has key roles in DENV infection, replication, and viral transmission (vector competence). Mosquito saliva also plays an important role during DENV transmission. In this study, we detected the presence of sialic acid (Sia) in Aedes aegypti tissues, which may have an important role during DENV-vector competence. We also identified genome sequences encoding enzymes involved in Sia pathways. The cDNA for Aedes aegypti CMP-Sia synthase (CSAS) was amplified, cloned, and functionally evaluated via the complementation of LEC29.Lec32 CSAS-deficient CHO cells. AedesCSAS-transfected LEC29.Lec32 cells were able to express Sia moieties on the cell surface. Sequences related to ?-2,6-sialyltransferase were detected in the Aedes aegypti genome. Likewise, we identified Sia-?-2,6-DENV interactions in different mosquito tissues. In addition, we evaluated the possible role of sialylated molecules in a salivary gland extract during DENV internalization in mammalian cells. The knowledge of early DENV-host interactions could facilitate a better understanding of viral tropism and pathogenesis to allow the development of new strategies for controlling DENV transmission. PMID:25874215

  18. Mosquitocidal properties of IgG targeting the glutamate-gated chloride channel in three mosquito disease vectors (Diptera: Culicidae).

    PubMed

    Meyers, Jacob I; Gray, Meg; Foy, Brian D

    2015-05-15

    The glutamate-gated chloride channel (GluCl) is a highly sensitive insecticide target of the avermectin class of insecticides. As an alternative to using chemical insecticides to kill mosquitoes, we tested the effects of purified immunoglobulin G (IgG) targeting the extracellular domain of GluCl from Anopheles gambiae (AgGluCl) on the survivorship of three key mosquito disease vectors: Anopheles gambiae s.s., Aedes aegypti and Culex tarsalis. When administered through a single blood meal, anti-AgGluCl IgG reduced the survivorship of A. gambiae in a dose-dependent manner (LC50: 2.82?mg?ml(-1), range 2.68-2.96?mg?ml(-1)) but not A. aegypti or C. tarsalis. We previously demonstrated that AgGluCl is only located in tissues of the head and thorax of A. gambiae. To verify that AgGluCl IgG is affecting target antigens found outside the midgut, we injected it directly into the hemocoel via intrathoracic injection. A single, physiologically relevant concentration of anti-AgGluCl IgG injected into the hemocoel equally reduced mosquito survivorship of all three species. To test whether anti-AgGluCl IgG was entering the hemocoel of each of these mosquitoes, we fed mosquitoes a blood meal containing anti-AgGluCl IgG and subsequently extracted their hemolymph. We only detected IgG in the hemolymph of A. gambiae, suggesting that resistance of A. aegypti and C. tarsalis to anti-AgGluCl IgG found in blood meals is due to deficient IgG translocation across the midgut. We predicted that anti-AgGluCl IgG's mode of action is by antagonizing GluCl activity. To test this hypothesis, we fed A. gambiae blood meals containing anti-AgGluCl IgG and the GluCl agonist ivermectin (IVM). Anti-AgGluCl IgG attenuated the mosquitocidal effects of IVM, suggesting that anti-AgGluCl IgG antagonizes IVM-induced activation of GluCl. Lastly, we stained adult, female A. aegypti and C. tarsalis for GluCl expression. Neuronal GluCl expression in these mosquitoes was similar to previously reported A. gambiae GluCl expression; however, we also discovered GluCl staining on the basolateral surface of their midgut epithelial cells, suggesting important physiological differences in Culicine and Anopheline mosquitoes. PMID:25994632

  19. Landscape factors influencing the spatial distribution and abundance of mosquito vector Culex quinquefasciatus (Diptera: Culicidae) in a mixed residential-agricultural community in Hawai'i

    USGS Publications Warehouse

    Reiter, M.E.; Lapointe, D.A.

    2007-01-01

    Mosquito-borne avian diseases, principally avian malaria (Plasmodium relictum Grassi and Feletti) and avian pox (Avipoxvirus sp.) have been implicated as the key limiting factor associated with recent declines of endemic avifauna in the Hawaiian Island archipelago. We present data on the relative abundance, infection status, and spatial distribution of the primary mosquito vector Culex quinquefasciatus Say (Diptera: Culicidae) across a mixed, residential-agricultural community adjacent to Hawai'i Volcanoes National Park on Hawai'i Island. We modeled the effect of agriculture and forest fragmentation in determining relative abundance of adult Cx. quinquefasciatus in Volcano Village, and we implement our statistical model in a geographic information system to generate a probability of mosquito capture prediction surface for the study area. Our model was based on biweekly captures of adult mosquitoes from 20 locations within Volcano Village from October 2001 to April 2003. We used mixed effects logistic regression to model the probability of capturing a mosquito, and we developed a set of 17 competing models a priori to specifically evaluate the effect of agriculture and fragmentation (i.e., residential landscapes) at two spatial scales. In total, 2,126 mosquitoes were captured in CO 2-baited traps with an average probability of 0.27 (SE = 0.10) of capturing one or more mosquitoes per trap night. Twelve percent of mosquitoes captured were infected with P. relictum. Our data indicate that agricultural lands and forest fragmentation significantly increase the probability of mosquito capture. The prediction surface identified areas along the Hawai'i Volcanoes National Park boundary that may have high relative abundance of the vector. Our data document the potential of avian malaria transmission in residential-agricultural landscapes and support the need for vector management that extends beyond reserve boundaries and considers a reserve's spatial position in a highly heterogeneous landscape.

  20. 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).

    PubMed

    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, P<0.05). The acetone extract of I. cairica leaf showed the most effective larvicidal action in Ae. aegypti 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, P<0.05). Therefore, this study suggests that the acetone extract of I. cairica leaf can be considered as plant-derived insecticide 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. PMID:25368088

  1. An update on the incidence of dengue gaining strength in Saudi Arabia and current control approaches for its vector mosquito

    PubMed Central

    2014-01-01

    Background The cases of dengue reported earlier in the late 1990s from the Kingdom of Saudi Arabia (KSA) occurred in the cities of Jeddah and Makkah. Although the kingdom has ample financial resources to establish effective control measures for the dengue vector, numerous cases of dengue occur and fluctuate in numbers from year to year. This necessitates a serious review of the current vector control strategies being practiced in order to identify the existing shortcomings. This short report provides an update on epidemiology of dengue in KSA (specifically in cities of Jeddah and Makkah) with a critical look at the current vector control strategies. Findings In 2013, 4411 cases of dengue were reported, with 8 cases of mortality. This number of dengue incidence was four times higher compared to 2012. In 2013, the highest number of 1272 dengue cases was reported in May, while the lowest number (37) of cases was reported in September. Conclusions It is evident that the control strategies of the dengue vector presently employed are inadequate. There seems to be serious deficiencies in following proper scientific procedures during field application(s) of control materials against the vector as is evident by the increases in the number of dengue cases as well as frequent outbreaks of the vector mosquito populations. In this review, some specific suggestions are made to draw attention to the relevant KSA authorities of the possible reasons behind unsuccessful control results and as to how to improve the strategy of dengue vector control in the kingdom. PMID:24890567

  2. West Nile Virus Transmission in Sentinel Chickens and Potential Mosquito Vectors, Senegal River Delta, 2008–2009

    PubMed Central

    Fall, Assane Gueye; Diaïté, Amadou; Seck, Momar Talla; Bouyer, Jérémy; Lefrançois, Thierry; Vachiéry, Nathalie; Aprelon, Rosalie; Faye, Ousmane; Konaté, Lassana; Lancelot, Renaud

    2013-01-01

    West Nile virus (WNV) is an arthropod-borne Flavivirus usually transmitted to wild birds by Culex mosquitoes. Humans and horses are susceptible to WNV but are dead-end hosts. WNV is endemic in Senegal, particularly in the Senegal River Delta. To assess transmission patterns and potential vectors, entomological and sentinel serological was done in Ross Bethio along the River Senegal. Three sentinel henhouses (also used as chicken-baited traps) were set at 100 m, 800 m, and 1,300 m from the river, the latter close to a horse-baited trap. Blood samples were taken from sentinel chickens at 2-week intervals. Seroconversions were observed in sentinel chickens in November and December. Overall, the serological incidence rate was 4.6% with 95% confidence interval (0.9; 8.4) in the sentinel chickens monitored for this study. Based on abundance pattern, Culex neavei was the most likely mosquito vector involved in WNV transmission to sentinel chickens, and a potential bridge vector between birds and mammals. PMID:24084679

  3. Neural responses to one- and two-tone stimuli in the hearing organ of the dengue vector mosquito

    PubMed Central

    Arthur, Ben J.; Wyttenbach, Robert A.; Harrington, Laura C.; Hoy, Ronald R.

    2010-01-01

    SUMMARY Recent studies demonstrate that mosquitoes listen to each other's wing beats just prior to mating in flight. Field potentials from sound-transducing neurons in the antennae contain both sustained and oscillatory components to pure and paired tone stimuli. Described here is a direct comparison of these two types of response in the dengue vector mosquito, Aedes aegypti. Across a wide range of frequencies and intensities, sustained responses to one- and two-tone stimuli are about equal in magnitude to oscillatory responses to the beats produced by two-tone stimuli. All of these responses are much larger than the oscillatory responses to one-tone stimuli. Similarly, the frequency range extends up to at least the fifth harmonic of the male flight tone for sustained responses to one- and two-tone stimuli and oscillatory responses at the beat frequency of two-tone stimuli, whereas the range of oscillatory response to a one-tone stimulus is limited to, at most, the third harmonic. Thresholds near the fundamental of the flight tone are lower for oscillatory responses than for sustained deflections, lower for males than for females, and within the behaviorally relevant range. A simple model of the transduction process can qualitatively account for both oscillatory and sustained responses to pure and paired tones. These data leave open the question as to which of several alternative strategies underlie flight tone matching behavior in mosquitoes. PMID:20348350

  4. Synthesis and characterization of silver nanoparticles using Gmelina asiatica leaf extract against filariasis, dengue, and malaria vector mosquitoes.

    PubMed

    Muthukumaran, Udaiyan; Govindarajan, Marimuthu; Rajeswary, Mohan; Hoti, S L

    2015-05-01

    Mosquitoes are blood-feeding insects and serve as the most important vectors for spreading human diseases such as malaria, yellow fever, dengue fever, and filariasis. The continued use of synthetic insecticides has resulted in resistance in mosquitoes. Synthetic insecticides are toxic and affect the environment by contaminating soil, water, and air, and then natural products may be an alternative to synthetic insecticides because they are effective, biodegradable, eco-friendly, and safe to environment. Botanical origin may serve as suitable alternative biocontrol techniques in the future. The present study was carried out to establish the larvicidal potential of leaf extracts of Gmelina asiatica and synthesized silver nanoparticles using aqueous leaf extract against late third instar larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. Larvae were exposed to varying concentrations of plant extracts and synthesized AgNPs for 24 h. The results were recorded from UV-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy analysis support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the larvae of An. stephensi (lethal dose (LC??)?=?22.44 ?g/mL; LC?? 40.65 ?g/mL), Ae. aegypti (LC???=?25.77 ?g/mL; LC?? 45.98 ?g/mL), and C. quinquefasciatus (LC???=?27.83 ?g/mL; LC?? 48.92 ?g/mL), respectively. No mortality was observed in the control. This is the first report on mosquito larvicidal activity of plant-synthesized nanoparticles. Thus, the use of G. asiatica to synthesize silver nanoparticles is a rapid, eco-friendly, and a single-step approach and the AgNps formed can be potential mosquito larvicidal agents. PMID:25666372

  5. The use of annual killifish in the biocontrol of the aquatic stages of mosquitoes in temporary bodies of fresh water; a potential new tool in vector control

    PubMed Central

    2010-01-01

    Background Mosquitoes that breed in temporary pools in remote areas that dry up seasonally are especially difficult to control through chemical or biological means. The annual killifish has been suggested as a means of eradicating the aquatic stages of mosquitoes in transient pools because they can maintain permanent populations in such habitats by undergoing suspended animation or diapause during the embryonic stages to survive periodic drought. However, very little is known about the predatory activity of annual killifish and their usefulness in mosquito control. Results The annual killifish, Nothobranchius guentheri, native to Tanzania, was used in this investigation. Food preference was tested under laboratory conditions by feeding juvenile killifish with 2nd instar mosquito larvae of Culex quinquefasciatus in the presence of alternative food sources, such as rotifers and chironomid larvae. Semi-field tests were conducted by introduction of hibernating killifish embryos and juvenile fish to artificial ponds in an outdoor open environment that allowed natural oviposition of Cx. quinquefasciatus. Food preference studies show that N. guentheri preferred to prey on mosquito larvae than either chironomid or rotifers. When hibernating killifish embryos were added to ponds simultaneously with the addition of freshwater, the embryos hatched and fed on mosquito larval population resulting in complete elimination of the immature stages. The introduction of juvenile fish to ponds with high density of mosquito larvae resulted in total eradication of the mosquito population due to predation by fish. Complete biocontrol of the mosquito larval population was achieved in the presence of 3 fish per m2 of pond surface area. Conclusions The annual killifish provides yet another tool that may be employed in the eradication diseases carried by mosquitoes through vector control, particularly in temporary bodies of freshwater. The fish can be conveniently transported in the absence of water in the form of hibernating embryos. Once introduced either as embryos or juveniles in ponds, the annual killifish can effectively reduce the larval population because of its aggressive predatory activity. PMID:20492714

  6. Impact of climate and mosquito vector abundance on sylvatic arbovirus circulation dynamics in Senegal.

    PubMed

    Althouse, Benjamin M; Hanley, Kathryn A; Diallo, Mawlouth; Sall, Amadou A; Ba, Yamar; Faye, Ousmane; Diallo, Diawo; Watts, Douglas M; Weaver, Scott C; Cummings, Derek A T

    2015-01-01

    Sylvatic arboviruses have been isolated in Senegal over the last 50 years. The ecological drivers of the pattern and frequency of virus infection in these species are largely unknown. We used time series analysis and Bayesian hierarchical count modeling on a long-term arbovirus dataset to test associations between mosquito abundance, weather variables, and the frequency of isolation of dengue, yellow fever, chikungunya, and Zika viruses. We found little correlation between mosquito abundance and viral isolations. Rainfall was a negative predictor of dengue virus (DENV) isolation but a positive predictor of Zika virus isolation. Temperature was a positive predictor of yellow fever virus (YFV) isolations but a negative predictor of DENV isolations. We found slight interference between viruses, with DENV negatively associated with concurrent YFV isolation and YFV negatively associated with concurrent isolation of chikungunya virus. These findings begin to characterize some of the ecological associations of sylvatic arboviruses with each other and climate and mosquito abundance. PMID:25404071

  7. In-silico homology modeling of three isoforms of insect defensins from the dengue vector mosquito, Aedes aegypti (Linn., 1762).

    PubMed

    Dhananjeyan, K J; Sivaperumal, R; Paramasivan, R; Thenmozhi, V; Tyagi, B K

    2009-05-01

    Dengue is a serious public health problem in tropical and subtropical countries. It is caused by any of the four serologically distinct dengue viruses, namely DENV1-4. The viruses are transmitted by Aedes mosquitoes. Understanding various defence mechanisms of insects has become a prime area of research worldwide. In insects, the first line of defence against invading pathogens includes cellular mechanisms and a battery of antimicrobial peptides such as defensins, cecropins etc. Defensins--cationic, cysteine-rich peptides consisting of approximately 40 amino acids with broad-spectrum activity against Gram-positive bacteria--have been reported from a wide range of organisms. In the dengue vector mosquito, Aedes aegypti, three isoforms of defensins are reported to be expressed in a spatial and temporal fashion. This report presents the three-dimensional structures of the three isoforms of Ae. aegypti defensins predicted by comparative modeling. Prediction was done with Modeller 9v1 and the structures validated through a series of tests. The best results of the prediction study are presented, and may help lead to the discovery of new synthetic peptides or derivatives of defensins that could be useful in the control of vector-borne diseases. PMID:19085024

  8. Entomopathogenic fungi for mosquito control: a review.

    PubMed

    Scholte, Ernst-Jan; Knols, Bart G J; Samson, Robert A; Takken, Willem

    2004-01-01

    Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito populations, and have been studied extensively. There are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. The discovery, in 1977, of the selective mosquito-pathogenic bacterium Bacillus thuringiensis Berliner israelensis (Bti) curtailed widespread interest in the search for other suitable biological control agents. In recent years interest in mosquito-killing fungi is reviving, mainly due to continuous and increasing levels of insecticide resistance and increasing global risk of mosquito-borne diseases. This review presents an update of published data on mosquito-pathogenic fungi and mosquito-pathogen interactions, covering 13 different fungal genera. Notwithstanding the potential of many fungi as mosquito control agents, only a handful have been commercialized and are marketed for use in abatement programs. We argue that entomopathogenic fungi, both new and existing ones with renewed/improved efficacies may contribute to an expansion of the limited arsenal of effective mosquito control tools, and that they may contribute in a significant and sustainable manner to the control of vector-borne diseases such as malaria, dengue and filariasis. PMID:15861235

  9. Made-to-measure malaria vector control strategies: rational design based on insecticide properties and coverage of blood resources for mosquitoes

    PubMed Central

    2014-01-01

    Eliminating malaria from highly endemic settings will require unprecedented levels of vector control. To suppress mosquito populations, vector control products targeting their blood hosts must attain high biological coverage of all available sources, rather than merely high demographic coverage of a targeted resource subset, such as humans while asleep indoors. Beyond defining biological coverage in a measurable way, the proportion of blood meals obtained from humans and the proportion of bites upon unprotected humans occurring indoors also suggest optimal target product profiles for delivering insecticides to humans or livestock. For vectors that feed only occasionally upon humans, preferred animal hosts may be optimal targets for mosquito-toxic insecticides, and vapour-phase insecticides optimized to maximize repellency, rather than toxicity, may be ideal for directly protecting people against indoor and outdoor exposure. However, for vectors that primarily feed upon people, repellent vapour-phase insecticides may be inferior to toxic ones and may undermine the impact of contact insecticides applied to human sleeping spaces, houses or clothing if combined in the same time and place. These concepts are also applicable to other mosquito-borne anthroponoses so that diverse target species could be simultaneously controlled with integrated vector management programmes. Measurements of these two crucial mosquito behavioural parameters should now be integrated into programmatically funded, longitudinal, national-scale entomological monitoring systems to inform selection of available technologies and investment in developing new ones. PMID:24739261

  10. Examination of the genetic basis for sexual dimorphism in the Aedes aegypti (dengue vector mosquito) pupal brain

    PubMed Central

    2014-01-01

    Background Most animal species exhibit sexually dimorphic behaviors, many of which are linked to reproduction. A number of these behaviors, including blood feeding in female mosquitoes, contribute to the global spread of vector-borne illnesses. However, knowledge concerning the genetic basis of sexually dimorphic traits is limited in any organism, including mosquitoes, especially with respect to differences in the developing nervous system. Methods Custom microarrays were used to examine global differences in female vs. male gene expression in the developing pupal head of the dengue vector mosquito, Aedes aegypti. The spatial expression patterns of a subset of differentially expressed transcripts were examined in the developing female vs. male pupal brain through in situ hybridization experiments. Small interfering RNA (siRNA)-mediated knockdown studies were used to assess the putative role of Doublesex, a terminal component of the sex determination pathway, in the regulation of sex-specific gene expression observed in the developing pupal brain. Results Transcripts (2,527), many of which were linked to proteolysis, the proteasome, metabolism, catabolic, and biosynthetic processes, ion transport, cell growth, and proliferation, were found to be differentially expressed in A. aegypti female vs. male pupal heads. Analysis of the spatial expression patterns for a subset of dimorphically expressed genes in the pupal brain validated the data set and also facilitated the identification of brain regions with dimorphic gene expression. In many cases, dimorphic gene expression localized to the optic lobe. Sex-specific differences in gene expression were also detected in the antennal lobe and mushroom body. siRNA-mediated gene targeting experiments demonstrated that Doublesex, a transcription factor with consensus binding sites located adjacent to many dimorphically expressed transcripts that function in neural development, is required for regulation of sex-specific gene expression in the developing A. aegypti brain. Conclusions These studies revealed sex-specific gene expression profiles in the developing A. aegypti pupal head and identified Doublesex as a key regulator of sexually dimorphic gene expression during mosquito neural development. PMID:25729562

  11. Current procedures of the integrated urban vector-mosquito control as an example in Cotonou (Benin, West Africa) and Wroc?aw area (Poland).

    PubMed

    Rydzanicz, Katarzyna; Lonc, Elzbieta; Becker, Norbert

    2009-01-01

    Current strategy of Integrated Vector Management (IVM) comprises the general approach of environmentally friendly control measures. With regard to mosquitoes it includes first of all application of microbial insecticides based on Bacillus thuringiensis israelensis (Bti) and B. sphaericus (Bs) delta-endotoxins as well as the reduction of breeding habitats and natural enemy augmentation. It can be achieved thorough implementation of the interdisciplinary program, i. e., understanding of mosquito vector ecology, the appropriate vector-diseases (e. g., malariometric) measurements and training of local personnel responsible for mosquito abatement activities, as well as community involvement. Biocontrol methods as an alternative to chemical insecticides result from the sustainability development concept, growing awareness of environmental pollution and the development of insecticide-resistant strains of vector-mosquito populations in many parts of the world. Although sustainable trends are usually considered in terms of the monetary and training resources within countries, environmental concerns are actually more limiting factors for the duration of an otherwise successful vector control effort. In order to meet these new needs, increasing efforts have been made in search of and application of natural enemies, such as parasites, bacterial pathogens and predators which may control populations of insect vectors. The biological control agent based on the bacterial toxins Bti and Bs has been used in the Wroc?aw's University and Municipal Mosquito Control Programs since 1998. In West-Africa biocontrol appears to be an effective and safe tool to combat malaria in addition to bed-nets, residual indoor spraying and appropriate diagnosis and treatment of malaria parasites which are the major tools in the WHO Roll Back Malaria Program. IVM studies carried out 2005-2008 in Cotonou (Benin) as well those in Wroc?aw Irrigated Fields during the last years include the following major steps: 1. Mapping of all breeding sites in the project area and recording data in a geographical information system (GIS/relational database). All districts, streets and houses are numbered for quick reference during the operation; 2. Studying mosquito vector bionomics, migration and vectorial capacity in the project area, before, during and after the routine Bti treatments; 3. Assessment of the optimum for effective larvicide insecticide dosages at major breeding sites against the different target mosquito species; 4. Implementation of the microbial control agents in the integrated routine program. Adaptation of the application equipment to the local situation, training of the field staff, and routine treatments; 5. Conducting surveillance of vector-disease (e. g., malariometric) parameters in the control and experimental area before, during, and after the application of biocontrol agents. PMID:20209805

  12. Genetic divergence between populations of feral and domestic forms of a mosquito disease vector assessed by transcriptomics

    PubMed Central

    2015-01-01

    Culex pipiens, an invasive mosquito and vector of West Nile virus in the US, has two morphologically indistinguishable forms that differ dramatically in behavior and physiology. Cx. pipiens form pipiens is primarily a bird-feeding temperate mosquito, while the sub-tropical Cx. pipiens form molestus thrives in sewers and feeds on mammals. Because the feral form can diapause during the cold winters but the domestic form cannot, the two Cx. pipiens forms are allopatric in northern Europe and, although viable, hybrids are rare. Cx. pipiens form molestus has spread across all inhabited continents and hybrids of the two forms are common in the US. Here we elucidate the genes and gene families with the greatest divergence rates between these phenotypically diverged mosquito populations, and discuss them in light of their potential biological and ecological effects. After generating and assembling novel transcriptome data for each population, we performed pairwise tests for nonsynonymous divergence (Ka) of homologous coding sequences and examined gene ontology terms that were statistically over-represented in those sequences with the greatest divergence rates. We identified genes involved in digestion (serine endopeptidases), innate immunity (fibrinogens and ?-macroglobulins), hemostasis (D7 salivary proteins), olfaction (odorant binding proteins) and chitin binding (peritrophic matrix proteins). By examining molecular divergence between closely related yet phenotypically divergent forms of the same species, our results provide insights into the identity of rapidly-evolving genes between incipient species. Additionally, we found that families of signal transducers, ATP synthases and transcription regulators remained identical at the amino acid level, thus constituting conserved components of the Cx. pipiens proteome. We provide a reference with which to gauge the divergence reported in this analysis by performing a comparison of transcriptome sequences from conspecific (yet allopatric) populations of another member of the Cx. pipiens complex, Cx. quinquefasciatus. PMID:25755934

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. Molecular and Functional Characterization of Odorant-Binding Protein Genes in an Invasive Vector Mosquito, Aedes albopictus

    PubMed Central

    Deng, Yuhua; Yan, Hui; Gu, Jinbao; Xu, Jiabao; Wu, Kun; Tu, Zhijian; James, Anthony A.; Chen, Xiaoguang

    2013-01-01

    Aedes albopictus is a major vector of dengue and Chikungunya viruses. Olfaction plays a vital role in guiding mosquito behaviors and contributes to their ability to transmit pathogens. Odorant-binding proteins (OBPs) are abundant in insect olfactory tissues and involved in the first step of odorant reception. While comprehensive descriptions are available of OBPs from Aedes aegypti, Culex quinquefasciatus and Anopheles gambiae, only a few genes from Ae. albopictus have been reported. In this study, twenty-one putative AalbOBP genes were cloned using their homologues in Ae. aegypti to query an Ae. albopictus partial genome sequence. Two antenna-specific OBPs, AalbOBP37 and AalbOBP39, display a remarkable similarity in their overall folding and binding pockets, according to molecular modeling. Binding affinity assays indicated that AalbOBP37 and AalbOBP39 had overlapping ligand affinities and are affected in different pH condition. Electroantennagrams (EAG) and behavioral tests show that these two genes were involved in olfactory reception. An improved understanding of the Ae. albopictus OBPs is expected to contribute to the development of more efficient and environmentally-friendly mosquito control strategies. PMID:23935894

  16. Research in mosquito control: current challenges for a brighter future.

    PubMed

    Benelli, Giovanni

    2015-08-01

    Mosquitoes (Diptera: Culicidae) are a key threat for millions of people worldwide, since they act as vectors for devastating pathogens and parasites. In this scenario, vector control is crucial. Mosquito larvae are usually targeted using organophosphates, insect growth regulators, and microbial agents. Indoor residual spraying and insecticide-treated bed nets are also employed. However, these chemicals have negative effects on human health and the environment and induce resistance in a number of vectors. Newer and safer tools have been recently implemented to enhance control of mosquitoes. Here, I focus on some crucial challenges about eco-friendly control of mosquito vectors, mainly the improvement of behavior-based control strategies (sterile insect technique ("SIT") and "boosted SIT") and plant-borne mosquitocidals, including green-synthesized nanoparticles. A number of hot areas that need further research and cooperation among parasitologists, entomologists, and behavioral ecologists are highlighted. PMID:26093499

  17. Fine-scale population genetic structure of a wildlife disease vector: The southern house mosquito on the island of Hawaii

    USGS Publications Warehouse

    Keyghobadi, N.; LaPointe, D.; Fleischer, R.C.; Fonseca, D.M.

    2006-01-01

    The southern house mosquito, Culex quinquefasciatus, is a widespread tropical and subtropical disease vector. In the Hawaiian Islands, where it was introduced accidentally almost two centuries ago, it is considered the primary vector of avian malaria and pox. Avian malaria in particular has contributed to the extinction and endangerment of Hawaii's native avifauna, and has altered the altitudinal distribution of native bird populations. We examined the population genetic structure of Cx. quinquefasciatus on the island of Hawaii at a smaller spatial scale than has previously been attempted, with particular emphasis on the effects of elevation on population genetic structure. We found significant genetic differentiation among populations and patterns of isolation by distance within the island. Elevation per se did not have a limiting effect on gene flow; however, there was significantly lower genetic diversity among populations at mid elevations compared to those at low elevations. A recent sample taken from just above the predicted upper altitudinal distribution of Cx. quinquefasciatus on the island of Hawaii was confirmed as being a temporary summer population and appeared to consist of individuals from more than one source population. Our results indicate effects of elevation gradients on genetic structure that are consistent with known effects of elevation on population dynamics of this disease vector. ?? 2006 The Authors.

  18. A comparison of two commercial mosquito traps for the capture of malaria vectors in northern belize, central america.

    PubMed

    Wagman, Joseph; Grieco, John P; Bautista, Kim; Polanco, Jorge; Briceño, Ireneo; King, Russell; Achee, Nicole L

    2014-09-01

    To achieve maximum success from any vector control intervention, it is critical to identify the most efficacious tools available. The principal aim of this study was to evaluate the efficacy of 2 commercially available adult mosquito traps for capturing Anopheles albimanus and An. vestitipennis, 2 important malaria vectors in northern Belize, Central America. Additionally, the impact of outdoor baited traps on mosquito entry into experimental huts was assessed. When operated outside of human-occupied experimental huts, the Centers for Disease Control and Prevention (CDC) miniature light trap, baited with human foot odors, captured significantly greater numbers of female An. albimanus per night (5.1 ± 1.9) than the Biogents Sentinel™ trap baited with BG-Lure™ (1.0 ± 0.2). The 2 trap types captured equivalent numbers of female An. vestitipennis per night, 134.3 ± 45.6 in the CDC trap and 129.6 ± 25.4 in the Sentinel trap. When compared to a matched control hut using no intervention, the use of baited CDC light traps outside an experimental hut did not impact the entry of An. vestitipennis into window interception traps, 17.1 ± 1.3 females per hour in experimental huts vs. 17.2 ± 1.4 females per hour in control huts. However, the use of outdoor baited CDC traps did significantly decrease the entry of An. albimanus into window interception traps from 3.5 ± 0.5 females per hour to 1.9 ± 0.2 females per hour. These results support existing knowledge that the underlying ecological and behavioral tendencies of different Anopheles species can influence trap efficacy. Furthermore, these findings will be used to guide trap selection for future push-pull experiments to be conducted at the study site. PMID:25843092

  19. Cell Phone-Based System (Chaak) for Surveillance of Immatures of Dengue Virus Mosquito Vectors

    PubMed Central

    LOZANO–FUENTES, SAUL; WEDYAN, FADI; HERNANDEZ–GARCIA, EDGAR; SADHU, DEVADATTA; GHOSH, SUDIPTO; BIEMAN, JAMES M.; TEP-CHEL, DIANA; GARCÍA–REJÓN, JULIÁN E.; EISEN, LARS

    2014-01-01

    Capture of surveillance data on mobile devices and rapid transfer of such data from these devices into an electronic database or data management and decision support systems promote timely data analyses and public health response during disease outbreaks. Mobile data capture is used increasingly for malaria surveillance and holds great promise for surveillance of other neglected tropical diseases. We focused on mosquito-borne dengue, with the primary aims of: 1) developing and field-testing a cell phone-based system (called Chaak) for capture of data relating to the surveillance of the mosquito immature stages, and 2) assessing, in the dengue endemic setting of Mérida, México, the cost-effectiveness of this new technology versus paper-based data collection. Chaak includes a desktop component, where a manager selects premises to be surveyed for mosquito immatures, and a cell phone component, where the surveyor receives the assigned tasks and captures the data. Data collected on the cell phone can be transferred to a central database through different modes of transmission, including near-real time where data are transferred immediately (e.g., over the Internet) or by first storing data on the cell phone for future transmission. Spatial data are handled in a novel, semantically driven, geographic information system. Compared with a pen-and-paper-based method, use of Chaak improved the accuracy and increased the speed of data transcription into an electronic database. The cost-effectiveness of using the Chaak system will depend largely on the up-front cost of purchasing cell phones and the recurring cost of data transfer over a cellular network. PMID:23926788

  20. 166 Journal of Vector Ecology June2008 Colonization of abandoned swimming pools by larval mosquitoes and their

    E-print Network

    Jordan, Frank

    of a novel aquatic habitat by mosquito larvae and their aquatic predators. We conducted a randomized survey of flooded swimming pools in two neighborhoods in January 2006 and found that 64% contained mosquito larvae that flooded the study area. Mosquito larvae were rare or absent from pools containing fishes; however, path

  1. Host-feeding patterns of potential mosquito vectors in Connecticut, U.S.A.: molecular analysis of bloodmeals from 23 species of Aedes, Anopheles, Culex, Coquillettidia, Psorophora, and Uranotaenia.

    PubMed

    Molaei, Goudarz; Andreadis, Theodore G; Armstrong, Philip M; Diuk-Wasser, Maria

    2008-11-01

    We evaluated the blood-feeding patterns in several mosquito species that may serve as vectors of disease agents in the northeastern United States. Blood-fed mosquitoes were collected from 91 different sites throughout Connecticut over a 6-yr period (June-October 2002-2007), and the host-feeding patterns of 23 mosquito species representing six genera were examined by using a polymerase chain reaction-based assay and sequencing portions of the cytochrome b gene of mitochondrial DNA. This study was part of a statewide surveillance program and for some of the mosquito species a limited number of specimens were examined [e.g., Aedes communis (De Geer) (1), Anopheles barberi Coquillett (1), Uranotaenia sapphirina (Osten Sacken) (5)]. With the exception of Culex territans Walker that acquired bloodmeals from all four classes of vertebrates--birds, reptiles, amphibians, and mammals--all species of Aedes, Anopheles, Coquillettidia, Psorophora, and to a lesser degree, Uranotaenia, were found to feed predominately upon mammalian hosts. Fourteen mammalian species were identified as sources of blood, but the majority of feedings were taken from the white-tailed deer, Odocoileus virginianus. Human-derived bloodmeals were identified from 13 of the 23 mosquito species. Limited avian-derived bloodmeals were detected in Aedes canadensis (Theobald), Aedes cantator (Coquillett), Aedes cinereus Meigen, Aedes triseriatus (Coquillett), Aedes trivittatus (Coquillett), Coquillettidia perturbans (Walker) Cx. territans, Psorophoraferox (von Humboldt), and Ur. sapphirina. American robin, Turdus migratorius, was the most common source of avian blood, followed by a few other mostly Passeriformes birds. We conclude that the white-tailed deer serve as the main vertebrate host for these mammalophilic mosquitoes in this region of the United States. This feeding pattern supports enzootic amplification of arboviruses, including Jamestown Canyon, Cache Valley, and Potosi viruses that perpetuate in cervid hosts. Occasional feeding on avian hosts suggests that some of these mosquito species, such as Cq. perturbans, also could facilitate transmission of West Nile and eastern equine encephalitis viruses from viremic birds to mammalian hosts. PMID:19058640

  2. Mosquitocidal properties of Calotropis gigantea (Family: Asclepiadaceae) leaf extract and bacterial insecticide, Bacillus thuringiensis, against the mosquito vectors.

    PubMed

    Kovendan, Kalimuthu; Murugan, Kadarkarai; Prasanna Kumar, Kanagarajan; Panneerselvam, Chellasamy; Mahesh Kumar, Palanisamy; Amerasan, Duraisamy; Subramaniam, Jayapal; Vincent, Savariar

    2012-08-01

    Calotropis gigantea leaf extract and Bacillus thuringiensis were tested first to fourth-instar larvae and pupae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The medicinal plants were collected from the area around Bharathiar University, Coimbatore, India. Calotropis gigantea leaf was washed with tap water and shade-dried at room temperature. An electrical blender powdered the dried plant materials (leaves). The powder 500 g of the leaf was extracted with 1.5 L of organic solvents of methanol for 8 h using a Soxhlet apparatus and filtered. The crude leaf extracts were evaporated to dryness in a rotary vacuum evaporator. The plant extract showed larvicidal and pupicidal effects after 24 h of exposure; no mortality was observed in the control group. For Calotropis gigantea, the median lethal concentration values (LC(50)) observed for the larvicidal and pupicidal activities against mosquito vector species Anopheles stephensi I to IV larval instars and pupae were 73.77, 89.64, 121.69, 155.49, and 213.79 ppm; Aedes aegypti values were 92.27, 106.60, 136.48, 164.01, and 202.56 ppm; and Culex quinquefasciatus values were 104.66, 127.71, 173.75, 251.65, and 314.70 ppm, respectively. For B. thuringiensis, the LC(50) values of I to IV larval instars and pupae of Anopheles stephensi were 37.24, 45.41, 57.82, 80.09, and 98.34 ppm; Aedes aegypti values were 42.38, 51.90, 71.02, 96.17, and 121.59 ppm; and Culex quinquefasciatus values were 55.85, 68.07, 94.11, 113.35, and 133.87 ppm, respectively. The study proved that the methanol leaf extract of Calotropis gigantea and bacterial insecticide B. thuringiensis has mosquitocidal property and was evaluated as target species of mosquito vectors. This is an ideal ecofriendly approach for the control of vector control programs. PMID:22382205

  3. Population dynamics of pest mosquitoes and potential malaria and West Nile virus vectors in relation to climatic factors and human activities in the Camargue, France.

    PubMed

    Ponçon, N; Toty, C; L'ambert, G; le Goff, G; Brengues, C; Schaffner, F; Fontenille, D

    2007-12-01

    The Camargue is an extensive wetland in the southeast of France, which is highly influenced by human activities. Large ponds, marshes and irrigated fields provide abundant potential breeding sites for mosquitoes. mosquitoes, which are important in terms of the nuisance they cause to people and animals, the limitations they impose on tourism and their potential threat to human health. Several of the mosquito species present are potential vectors of malaria and West Nile virus. Therefore, the population dynamics of these species were monitored over an entire breeding season during March-October 2005. Mosquito populations were sampled in two study areas once every 2 weeks, using CDC light traps baited with CO(2). Sixteen species were collected. The majority (98.7%) of the catch were Aedes caspius (Pallas) (Diptera: Culicidae), Culex modestus (Ficalbi), Culex pipiens L. and Anopheles hyrcanus (Pallas). The population dynamics of these species varied considerably in relation to the species' biology, climatic conditions (rainfall, temperature and season), water management, implementation of mosquito control campaigns and landscape use. PMID:18092973

  4. The Effect of Virus-Blocking Wolbachia on Male Competitiveness of the Dengue Vector Mosquito, Aedes aegypti

    PubMed Central

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

    2014-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance 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. PMID:25502564

  5. Vector control for malaria and other mosquito-borne diseases. Report of a WHO study group.

    PubMed

    1995-01-01

    Since the Ministerial Conference on Malaria in 1992, which acknowledged the urgent need for worldwide commitment to malaria control, efforts have been directed to implementation of a Global Malaria Control Strategy. Vector control, an essential component of malaria control, has become less effective in recent years, partly as a result of poor use of alternative control tools, inappropriate use of insecticides, lack of an epidemiological basis for interventions, inadequate resources and infrastructure, and weak management. Changing environmental conditions, the behavioural characteristics of certain vectors, and resistance to insecticides have added to the difficulties. This report of a WHO Study Group provides guidelines for the planning, implementation and evaluation of cost-effective and sustainable vector control in the context of the Global Malaria Control Strategy. It reviews the available methods - indoor residual spraying, personal protection, larval control and environmental management - stressing the need for selective and flexible use of interventions according to local conditions. Requirements for data collection and the appropriate use of entomological parameters and techniques are discussed and priorities identified for the development of local capacity for vector control and for operational research. Emphasis is placed both on the monitoring and evaluation of vector control to ensure cost-effectiveness and on the development of strong managerial structures, which can support community participation and intersectoral collaboration and accommodate the control of other vector-borne diseases. The report concludes with recommendations aimed at promoting the targeted and efficient use of vector control in preventing and controlling malaria, thereby reducing the threat to health and socioeconomic development in many tropical countries. PMID:8540245

  6. Barcoding Turkish Culex mosquitoes to facilitate arbovirus vector incrimination studies reveals hidden diversity and new potential vectors.

    PubMed

    Gunay, Filiz; Alten, Bulent; Simsek, Fatih; Aldemir, Adnan; Linton, Yvonne-Marie

    2015-03-01

    As a precursor to planned arboviral vector incrimination studies, an integrated systematics approach was adopted using morphology and DNA barcoding to examine the Culex fauna present in Turkey. The mitochondrial COI gene (658bp) were sequenced from 185 specimens collected across 11 Turkish provinces, as well as from colony material. Although by morphology only 9 species were recognised, DNA barcoding recovered 13 distinct species including: Cx. (Barraudius) modestus, Cx. (Culex) laticinctus, Cx. (Cux.) mimeticus, Cx. (Cux.) perexiguus, Cx. (Cux.) pipiens, Cx. (Cux.) pipiens form molestus, Cx. (Cux.) quinquefasciatus, Cx. (Cux.) theileri, Cx. (Cux.) torrentium, Cx. (Cux.) tritaeniorhynchus and Cx. (Maillotia) hortensis. The taxon formerly identified as Cx. (Neoculex) territans was shown to comprise two distinct species, neither of which correspond to Cx. territans s.s. These include Cx. (Neo.) impudicus and another uncertain species, which may be Cx. (Neo.) europaeus or Cx. (Neo.) martinii (herein=Cx. (Neo.) sp. 1). Detailed examination of the Pipiens Group revealed Cx. pipiens, Cx. pipiens f. molestus and the widespread presence of the highly efficient West Nile virus vector Cx. quinquefasciatus for the first time. Four new country records are reported, increasing the Culex of Turkey to 15 recognised species and Cx. pipiens f. molestus. A new taxonomic checklist is provided, annotated with respective vector competencies for transmission of arboviruses. PMID:25446171

  7. Venezuelan equine encephalitis virus in the mosquito vector Aedes taeniorhynchus: infection initiated by a small number of susceptible epithelial cells and a population bottleneck.

    PubMed

    Smith, Darci R; Adams, A Paige; Kenney, Joan L; Wang, Eryu; Weaver, Scott C

    2008-03-01

    We evaluated infection of Aedes taeniorhynchus mosquitoes, vectors of Venezuelan equine encephalitis virus (VEEV), using radiolabeled virus and replicon particles expressing green (GFP) or cherry fluorescent protein (CFP). More epidemic VEEV bound to and infected mosquito midguts compared to an enzootic strain, and a small number of midgut cells was preferentially infected. Chimeric replicons infected midgut cells at rates comparable to those of the structural gene donor. The numbers of midgut cells infected averaged 28, and many infections were initiated in only 1-5 cells. Infection by a mixture of GFP- and CFP-expressing replicons indicated that only about 100 midgut cells were susceptible. Intrathoracic injections yielded similar patterns of replication with both VEEV strains, suggesting that midgut infection is the primary limitation to transmission. These results indicate that the structural proteins determine initial infection of a small number of midgut cells, and that VEEV undergoes population bottlenecks during vector infection. PMID:18023837

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

    PubMed

    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. PMID:17337133

  9. Anti-mosquito plants as an alternative or incremental method for malaria vector control among rural communities of Bagamoyo District, Tanzania

    PubMed Central

    2014-01-01

    Background Plants represent one of the most accessible resources available for mosquito control by communities in Tanzania. However, no documented statistics exist for their contribution in the management of mosquitoes and other insects except through verbal and some publications. This study aimed at assessing communities’ knowledge, attitudes and practices of using plants as an alternative method for mosquito control among selected communities in a malaria-prone area in Tanzania. Methods Questionnaires were administered to 202 respondents from four villages of Bagamoyo District, Pwani Region, in Tanzania followed by participatory rural appraisal with village health workers. Secondary data collection for plants mentioned by the communities was undertaken using different search engines such as googlescholar, PubMED and NAPRALERT. Results Results showed about 40.3% of respondents used plants to manage insects, including mosquitoes. A broad profile of plants are used, including “mwarobaini” (Azadirachta indica) (22.5%), “mtopetope” (Annona spp) (20.8%), “mchungwa/mlimau” (Citrus spp) (8.3%), “mvumbashi/uvumbati” (Ocimum spp) (7.4%), “mkorosho” (Anacadium occidentale) (7.1%), “mwembe” (5.4%) (Mangifera indica), “mpera” (4.1%) (Psidium spp) and “maganda ya nazi” (4.1%) (Cocos nucifera). Majority of respondents collected these plants from the wild (54.2%), farms (28.9%) and/or home gardens (6%). The roles played by these plants in fighting mosquitoes is reflected by the majority that deploy them with or without bed-nets (p > 0.55) or insecticidal sprays (p >0.22). Most respondents were aware that mosquitoes transmit malaria (90.6%) while few respondents associated elephantiasis/hydrocele (46.5%) and yellow fever (24.3%) with mosquitoes. Most of the ethnobotanical uses mentioned by the communities were consistent with scientific information gathered from the literature, except for Psidium guajava, which is reported for the first time in insect control. Conclusion This survey has indicated some knowledge gap among community members in managing mosquito vectors using plant. The communities need a basic health education and sensitization for effective exploitation of this valuable tool for reducing mosquitoes and associated disease burdens. On the other hand, the government of Tanzania should strengthen advocacy of botanical pesticides development, registration and regulation for public health benefits because they are source of pest control tools people rely on them. PMID:25015092

  10. The role of male harassment on female fitness for the dengue vector mosquito Aedes aegypti

    PubMed Central

    Helinski, Michelle E.H.; Harrington, Laura C.

    2014-01-01

    Sexual harassment studies in insects suggest that females can incur several kinds of costs from male harassment and mating. Here, we examined direct and indirect costs of male harassment on components of female fitness in the predominantly monandrous mosquito Aedes aegypti. To disentangle the costs of harassment versus the costs of mating, we held females at a low or high density with males whose claspers were modified to prevent insemination, and compared these to females held with normal males and to those held with females or alone. A reduced longevity was observed when females were held under high density conditions with males or females, regardless if male claspers had been modified. There was no consistent effect of harassment on female fecundity. Net reproductive rate (R0) was higher in females held at low density with normal males compared to females held with males in the other treatments, even though only a small number of females showed direct evidence of remating. Indirect costs and benefits that were not due to harassment alone were observed. Daughters of females held with normal males at high density had reduced longevity compared to daughters from females held without conspecifics. However, their fitness (R0) was higher compared to females in all other treatments. Overall, our results indicate that A. aegypti females do not suffer a fitness cost from harassment of males when kept at moderate densities, and they suggest the potential for benefits obtained from ejaculate components. PMID:25544799

  11. Efficient transformation of the yellow fever mosquito Aedes aegypti using the piggyBac transposable element vector pBac[3xP3-EGFP afm

    Microsoft Academic Search

    V. Kokoza; A. Ahmed; E. A. Wimmer; A. S. Raikhel

    2001-01-01

    We report efficient germ-line transformation in the yellow fever mosquito Aedes aegypti accomplished using the piggyBac transposable element vector pBac[3xP3-EGFP afm]. Two transgenic lines were established and characterized; each contained the Vg-Defensin A transgene with strong eye-specific expression of the enhanced green fluorescent protein (EGFP) marker gene regulated by the artificial 3xP3 promoter. Southern blot hybridization and inverse PCR analyses

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

    Microsoft Academic Search

    Nandita Chowdhury; Anupam Ghosh; Goutam Chandra

    2008-01-01

    BACKGROUND: 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. Although several plants have been reported for mosquitocidal activity, only a few botanicals have moved from the laboratory to field use, because they are poorly characterized, in most cases active

  13. Efficient transformation of the yellow fever mosquito Aedes aegypti using the piggyBac transposable element vector pBac[3xP3-EGFP afm].

    PubMed

    Kokoza, V; Ahmed, A; Wimmer, E A; Raikhel, A S

    2001-11-01

    We report efficient germ-line transformation in the yellow fever mosquito Aedes aegypti accomplished using the piggyBac transposable element vector pBac[3xP3-EGFP afm]. Two transgenic lines were established and characterized; each contained the Vg-Defensin A transgene with strong eye-specific expression of the enhanced green fluorescent protein (EGFP) marker gene regulated by the artificial 3xP3 promoter. Southern blot hybridization and inverse PCR analyses of genomic DNA demonstrated a precise piggyBac-mediated, single copy insertion of the pBac[3xP3-EGFP afm,Vg-DefA] transposon in each transgenic line. For each line, genetic analysis confirmed stability and integrity of the entire transposon construct in the mosquito genome through the G2-G6 generations. Successful establishment of homozygous transgenic lines indicated that in both cases a non-lethal integration of the transposon into the mosquito genome had occurred. The 3xP3-EGFP marker was tested in mosquitoes with different genetic backgrounds. In white-eyed transgenic mosquitoes, the strong eye-specific expression of GFP was observed throughout all stages of development, starting from newly hatched first instar larvae to adults. A similar level and pattern of fluorescence was observed in red-eyed mosquitoes that were generated by crossing the 3xP3-EGFP transformants with the kh(w) white-eye mosquitoes transformed with the Drosophila cinnabar gene. Importantly, the utility of the 3xP3-EGFP, as marker gene for transformation of wild type mosquitoes, was demonstrated by strong eye-specific GFP expression in larval and pupal stages of black-eyed hybrids of the 3xP3-EGFP white-eye transformants and the wild type Rockefeller/UGAL strain. Finally, analysis of the Vg-DefA transgene expression in transformants from two established lines demonstrated strong blood-meal activation and fat-body-specific expression regulated by the Vg 1.8-kb 5' upstream region. PMID:11583926

  14. Larval habitats of potential mosquito vectors of West Nile virus in the Florida Keys.

    PubMed

    Hribar, Lawrence J

    2007-03-01

    The occurrence of larvae of two potential vectors of West Nile virus, Culex nigripalpus and Culex quinquefasciatus, was examined in the Florida Keys. About half of the aquatic habitats examined contained larvae of either one or both of the species. Culex quinquefasciatus was the most frequently encountered species, whereas only 9% of habitats sampled contained Culex nigripalpus. Over half of those samples that contained Culex nigripalpus also contained Culex quinquefasciatus. The two species utilize similar larval habitats in the Florida Keys, Monroe County, Florida, USA. PMID:17402282

  15. Anthropogenic Landscape Change and Vectors in New Zealand: Effects of Shade and Nutrient Levels on Mosquito Productivity

    Microsoft Academic Search

    Paul T. Leisnham; Philip J. Lester; David P. Slaney; Philip Weinstein

    2004-01-01

    Anthropogenic environmental changes, such as deforestation, agriculture, and introduced exotic species, have often coincided with an increase in mortality and morbidity from mosquito-borne diseases worldwide. Deforestation and agricultural development are likely to regulate immature mosquito populations through the addition of nutrients from livestock waste, decreased shade resulting in increased insolation (solar radiation), and the proliferation of artificial container habitats. We

  16. Review of the Minimus Complex of Anopheles, main malaria vector in Southeast Asia: from taxonomic issues to vector control strategies

    Microsoft Academic Search

    C. Garros; W. Van Bortel; H. D. Trung; M. Coosemans; S. Manguin

    2006-01-01

    Summary background The Minimus Complex of Anopheles subgenus Cellia is composed of two sibling species, A and C, on the Southeast Asian mainland, and a third allopatric species E that occurs in the Ryukyu Archipelago (Japan), a malaria-free region. Anopheles minimus s.l. is considered to be one of the main malaria vector in the hilly forested regions of Southeast Asia.

  17. Multiple Origins of Knockdown Resistance Mutations in the Afrotropical Mosquito Vector Anopheles gambiae

    PubMed Central

    Pinto, João; Lynd, Amy; Vicente, José L.; Santolamazza, Federica; Randle, Nadine P.; Gentile, Gabriele; Moreno, Marta; Simard, Frédéric; Charlwood, Jacques Derek; do Rosário, Virgílio E.; Caccone, Adalgisa; della Torre, Alessandra; Donnelly, Martin J.

    2007-01-01

    How often insecticide resistance mutations arise in natural insect populations is a fundamental question for understanding the evolution of resistance and also for modeling its spread. Moreover, the development of resistance is regarded as a favored model to study the molecular evolution of adaptive traits. In the malaria vector Anopheles gambiae two point mutations (L1014F and L1014S) in the voltage-gated sodium channel gene, that confer knockdown resistance (kdr) to DDT and pyrethroid insecticides, have been described. In order to determine whether resistance alleles result from single or multiple mutation events, genotyping of the kdr locus and partial sequencing of the upstream intron-1 was performed on a total of 288 A. gambiae S-form collected from 28 localities in 15 countries. Knockdown resistance alleles were found to be widespread in West Africa with co-occurrence of both 1014S and 1014F in West-Central localities. Differences in intron-1 haplotype composition suggest that kdr alleles may have arisen from at least four independent mutation events. Neutrality tests provided evidence for a selective sweep acting on this genomic region, particularly in West Africa. The frequency and distribution of these kdr haplotypes varied geographically, being influenced by an interplay between different mutational occurrences, gene flow and local selection. This has important practical implications for the management and sustainability of malaria vector control programs. PMID:18043750

  18. wFlu: Characterization and Evaluation of a Native Wolbachia from the Mosquito Aedes fluviatilis as a Potential Vector Control Agent

    PubMed Central

    Gonçalves, Daniela da Silva; Moreira, Luciano Andrade

    2013-01-01

    There is currently considerable interest and practical progress in using the endosymbiotic bacteria Wolbachia as a vector control agent for human vector-borne diseases. Such vector control strategies may require the introduction of multiple, different Wolbachia strains into target vector populations, necessitating the identification and characterization of appropriate endosymbiont variants. Here, we report preliminary characterization of wFlu, a native Wolbachia from the neotropical mosquito Aedes fluviatilis, and evaluate its potential as a vector control agent by confirming its ability to cause cytoplasmic incompatibility, and measuring its effect on three parameters determining host fitness (survival, fecundity and fertility), as well as vector competence (susceptibility) for pathogen infection. Using an aposymbiotic strain of Ae. fluviatilis cured of its native Wolbachia by antibiotic treatment, we show that in its natural host wFlu causes incomplete, but high levels of, unidirectional cytoplasmic incompatibility, has high rates of maternal transmission, and no detectable fitness costs, indicating a high capacity to rapidly spread through host populations. However, wFlu does not inhibit, and even enhances, oocyst infection with the avian malaria parasite Plasmodium gallinaceum. The stage- and sex-specific density of wFlu was relatively low, and with limited tissue distribution, consistent with the lack of virulence and pathogen interference/symbiont-mediated protection observed. Unexpectedly, the density of wFlu was also shown to be specifically-reduced in the ovaries after bloodfeeding Ae. fluviatilis. Overall, our observations indicate that the Wolbachia strain wFlu has the potential to be used as a vector control agent, and suggests that appreciable mutualistic coevolution has occurred between this endosymbiont and its natural host. Future work will be needed to determine whether wFlu has virulent host effects and/or exhibits pathogen interference when artificially-transfected to the novel mosquito hosts that are the vectors of human pathogens. PMID:23555728

  19. Novel flaviviruses from mosquitoes: Mosquito-specific evolutionary lineages within the phylogenetic group of mosquito-borne flaviviruses

    E-print Network

    Huhtamo, Eili; Cook, Shelley; Moureau, Gregory; Uzcátegui, Nathalie Y.; Sironen, Tarja; Kuivanen, Suvi; Putkuri, Niina; Kurkela, Satu; Harbach, Ralph E.; Firth, Andrew E.; Vapalahti, Olli; Gould, Ernest A.; de Lamballerie, Xavier

    2014-08-09

    . The MBFVs can be divided into two main groups based on their mosquito-vector associations (Gaunt et al., 2001). The flaviviruses transmitted by Stegomyia mosquito species, which include yellow fever virus (YFV) and dengue virus (DENV), have life cycles... -borne flaviviruses. In the ORF analysis both of these lineages were positioned between the large cluster of YFV-related viruses (Edge Hill, yellow fever and the Entebbe bat virus group) and the rest of the MBFVs including dengue virus and the JEV complex. NOUV...

  20. Evaluation of leaf extracts of Vitex negundo L. (Family: Verbenaceae) against larvae of Culex tritaeniorhynchus and repellent activity on adult vector mosquitoes.

    PubMed

    Karunamoorthi, Kaliyaperumal; Ramanujam, Sayeenathan; Rathinasamy, Rajendran

    2008-08-01

    Petroleum ether (60-80 degrees C) extracts of the leaves of Vitex negundo (Verbenaceae) were evaluated for larvicidal activity against larval stages of Culex tritaeniorhynchus in the laboratory. Larvae of C. tritaeniorhynchus were found more susceptible, with LC(50) and LC(90) values of 2.4883 and 5.1883 mg/l, respectively. Human volunteers wearing special terricot (68:32) fabrics, in the form of armbands, anklets, headbands, collar, and shoulder and pocket strips impregnated with V. negundo leaf extract were used, to test their repellent efficacy at two concentrations viz., 1.5 and 2.0 mg/cm(2) under the field conditions. At 1.5-mg/cm(2) concentration, more efficacies were found and 6-h complete protection against mosquito bites was provided. Complete protections for 8 h were found at 2.0 mg/cm(2) against mosquitoes bites. These results clearly reveal that the V. negundo leaf extract served as a potential larvicidal agent against Japanese encephalitis vector C. tritaeniorhynchus and additionally acted as a promising repellent against various adult vector mosquitoes. PMID:18500538

  1. Larvicidal activity of selected plant hydrodistillate extracts against the house mosquito, Culex pipiens, a West Nile virus vector.

    PubMed

    Cetin, Huseyin; Yanikoglu, Atila; Cilek, James E

    2011-04-01

    The larvicidal activity of hydrodistillate extracts from Chrysanthemum coronarium L., Hypericum scabrum L., Pistacia terebinthus L. subsp. palaestina (Boiss.) Engler, and Vitex agnus castus L. was investigated against the West Nile vector, Culex pipiens L. (Diptera: Culicidae). Yield and identification of the major essential oils from each distillation was determined by GC-MS analyses. The major essential oil component for each plant species was as follows: ?-pinene for P. terebinthus palaestina, and H. scabrum (45.3% and 42.3%, respectively), trans-?-caryophyllene for V. agnus castus (22.1%), and borneol for C. coronarium (20.9%). A series of distillate concentrations from these plants (that ranged from 1 ppm to 500 ppm, depending on plant species) were assessed against late third to early fourth C. pipiens larvae at 1, 6, and 24 h posttreatment. In general, larval mortality to water treated with a distillate increased as concentration and exposure time increased. H. scabrum and P. terebinthus palaestina were most effective against the mosquito larvae and both produced 100% mortality at 250 ppm at 24-h continuous exposure compared with the other plant species. Larval toxicity of the distillates at 24 h (LC(50) from most toxic to less toxic) was as follows: P. terebinthus palaestina (59.2 ppm) > H. scabrum (82.2 ppm) > V. agnus castus (83.3 ppm) > C. coronarium (311.2 ppm). But when LC(90) values were compared, relative toxicity ranking changed as follows: H. scabrum (185.9 ppm) > V. agnus castus (220.7 ppm) > P. terebinthus palaestina (260.7 ppm) > C. coronarium (496.3 ppm). Extracts of native Turkish plants continue to provide a wealth of potential sources for biologically active agents that may be applied against arthropod pests of man and animals. PMID:21053014

  2. Mechanisms of Pyrethroid Resistance in the Dengue Mosquito Vector, Aedes aegypti: Target Site Insensitivity, Penetration, and Metabolism

    PubMed Central

    Kasai, Shinji; Komagata, Osamu; Itokawa, Kentaro; Shono, Toshio; Ng, Lee Ching; Kobayashi, Mutsuo; Tomita, Takashi

    2014-01-01

    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. PMID:24945250

  3. Lethal effects of Aspergillus niger against mosquitoes vector of filaria, malaria, and dengue: a liquid mycoadulticide.

    PubMed

    Singh, Gavendra; Prakash, Soam

    2012-01-01

    Aspergillus niger is a fungus of the genus Aspergillus. It has caused a disease called black mold on certain fruits and vegetables. The culture filtrates released from the A. niger ATCC 66566 were grown in Czapek dox broth (CDB) then filtered with flash chromatograph and were used for the bioassay after a growth of thirty days. The result demonstrated these mortalities with LC(50), LC(90), and LC(99) values of Culex quinquefasciatus 0.76, 3.06, and 4.75, Anopheles stephensi 1.43, 3.2, and 3.86, and Aedes aegypti 1.43, 2.2, and 4.1 ?l/cm(2), after exposure of seven hours. We have calculated significant LT(90) values of Cx. quinquefasciatus 4.5, An. stephensi 3.54, and Ae. aegypti 6.0 hrs, respectively. This liquid spray of fungal culture isolate of A. niger can reduce malaria, dengue, and filarial transmission. These results significantly support broadening the current vector control paradigm beyond chemical adulticides. PMID:22629156

  4. Volatile phytochemicals as mosquito semiochemicals

    PubMed Central

    Nyasembe, Vincent O.; Torto, Baldwyn

    2014-01-01

    Plant biochemical processes result in the release of an array of volatile chemical substances into the environment, some of which are known to play important plant fitness enhancing functions, such as attracting pollinators, thermal tolerance of photosynthesis, and defense against herbivores. Cunningly, phytophagous insects have evolved mechanisms to utilize these volatiles to their own advantage, either to colonize a suitable host for feeding, reproduction and oviposition or avoid an unsuitable one. The volatile compounds involved in plant–insect chemical interactions have been widely exploited in the management of agricultural pests. On the other hand, use of plant volatiles in the management of medically important insects is limited, mainly due to paucity of information on their role in disease vector–plant interactions. To date, a total of 29 plant volatile compounds from various chemical classes, including phenols, aldehydes, alcohols, ketones and terpenes, have been identified as mosquito semiochemicals. In this review, we present highlights of mosquito–plant interactions, the available evidence of nectar feeding, with particular emphasis on sources of plant attractants, methods of plant volatile collection and the candidate plant volatile compounds that attract mosquitoes to nectar sources. We also highlight the potential application of these phytochemical attractants in integrated mosquito management. PMID:25383131

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

    NASA Technical Reports Server (NTRS)

    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.

  6. Population genetics of two key mosquito vectors of rift valley Fever virus reveals new insights into the changing disease outbreak patterns in kenya.

    PubMed

    Tchouassi, David P; Bastos, Armanda D S; Sole, Catherine L; Diallo, Mawlouth; Lutomiah, Joel; Mutisya, James; Mulwa, Francis; Borgemeister, Christian; Sang, Rosemary; Torto, Baldwyn

    2014-12-01

    Rift Valley fever (RVF) outbreaks in Kenya have increased in frequency and range to include northeastern Kenya where viruses are increasingly being isolated from known (Aedes mcintoshi) and newly-associated (Ae. ochraceus) vectors. The factors contributing to these changing outbreak patterns are unclear and the population genetic structure of key vectors and/or specific virus-vector associations, in particular, are under-studied. By conducting mitochondrial and nuclear DNA analyses on >220 Kenyan specimens of Ae. mcintoshi and Ae. ochraceus, we uncovered high levels of vector complexity which may partly explain the disease outbreak pattern. Results indicate that Ae. mcintoshi consists of a species complex with one of the member species being unique to the newly-established RVF outbreak-prone northeastern region of Kenya, whereas Ae. ochraceus is a homogeneous population that appears to be undergoing expansion. Characterization of specimens from a RVF-prone site in Senegal, where Ae. ochraceus is a primary vector, revealed direct genetic links between the two Ae. ochraceus populations from both countries. Our data strongly suggest that unlike Ae. mcintoshi, Ae. ochraceus appears to be a relatively recent, single 'introduction' into Kenya. These results, together with increasing isolations from this vector, indicate that Ae. ochraceus will likely be of greater epidemiological importance in future RVF outbreaks in Kenya. Furthermore, the overall vector complexity calls into question the feasibility of mosquito population control approaches reliant on genetic modification. PMID:25474018

  7. Temporal and spatial distribution of dengue vector mosquitoes and their habitat patterns in Penang Island, Malaysia.

    PubMed

    Saifur, Rahman G M; Hassan, Ahmad Abu; Dieng, Hamady; Salmah, Md Rawi Che; Saad, Ahmad Ramli; Satho, Tomomitsu

    2013-03-01

    We studied the diversity of Aedes breeding sites in various urban, suburban, and rural areas over time between February 2009 and February 2010 in the dengue endemic areas of Penang Island, Malaysia. We categorized the breeding sites and efficiency, and identified the key breeding containers. Among the 3 areas, the rural areas produced the highest container index (55), followed by suburban (42) and urban (32) areas. The numbers of key premises and containers were significantly higher (P < 0.000) in rural areas. The class 1 containers were identified as the key containers with higher productivity and efficiency, although class 2 and class 4 are the highest in numbers. Aedes aegypti immatures were found mostly in drums, water reservoirs, and polyethylene sheets, while mixed breeding was more common in buckets and empty paint cans in urban and suburban areas. Aedes albopictus was found mainly in miscellaneous containers such as drums, empty paint cans, and covers in all areas. The main potential containers indoors were drums, water reservoirs, and empty paint cans, and containers outdoors included empty paint cans, drums, and polyethylene sheets. PMID:23687853

  8. The entomopathogenic fungus Metarhizium anisopliae for mosquito control. Impact on the adult stage of the African malaria vector Anopheles gambiae and filariasis vector Culex quinquefasciatus

    Microsoft Academic Search

    E. J. Scholte

    2004-01-01

    Insect-pathogenie fungi for mosquito control (Chapters 1-3)Malaria and lymphatic tilariasis impose serious human health burdens in the tropics. Up to 500 million cases of malaria are reported annually, resulting in an estimated 1.5-2.7million deaths, of which 90% occur in sub-Saharan Africa. Malaria is caused by protozoa of the genus Plasmodium and is transmitted through bites of mosquitoes belonging to the

  9. Actin protein up-regulated upon infection and development of the filarial parasite, Wuchereria bancrofti (Spirurida: Onchocercidae), in the vector mosquito, Culex quinquefasciatus (Diptera: Culicidae).

    PubMed

    Agiesh Kumar, B; Paily, K P

    2008-03-01

    Detection and identification of humoral proteins, which are up-regulated in Culex quinquefasciatus upon infection by Wuchereria bancrofti, is important in tracing out the biochemical consequences of the filarial parasite development in the vector mosquito. Analysis of the haemolymph of infected mosquitoes through SDS-PAGE and RP-HPLC showed up-regulation of five proteins of molecular weights 40, 66, 22, 14, and 7-kDa. Among these, only the 40-kDa was unknown and the others were comparable with those already reported as transferrin, attacin, lysozyme, and defensin, respectively. In the present study, the 40-kDa protein up-regulated upon infection was identified as actin through nano-LC-MS/MS analysis. Actin is known to be one of the cytoskeletal proteins up-regulated in the haemolymph, as part of the innate immune system, of Escherichia coli challenged Drosophila melanogaster larvae. For the first time, we have observed an increased level of actin in the haemolymph of W. bancrofti-infected Cx. quinquefasciatus. However, the exact mechanism of actin involvement in the immune system of this mosquito is yet to be studied. PMID:17931628

  10. Structural changes of the follicular cells during developmental stages of the malaria vector mosquitoes Anopheles pharoensis (Diptera: Culicidae) in Egypt.

    PubMed

    Yamany, Abeer S; Adham, Fatma K; Mehlhorn, Heinz

    2014-11-01

    The structure modulation of follicular cells and the ovarian changes during fourth larval instar and pupal stage of the malaria vector mosquitoes Anopheles pharoensis Theobald were investigated using the light and electron microscopy. The generative organs consist of a pair of polytrophic ovaries (OV), which are oblong, spindle-shaped bodies, lying dorsolaterally and occupying the region from the mid-fifth to the mid-sixth abdominal segment in the fourth larval instar, while in the pupal stage, each ovary (OV) is situated in the haemocoel of the sixth abdominal segment. It is an oblong body slightly larger in diameter; the lumen of the calyx becomes wider and central, and the pedicel (P) consists of one row of compact discoidal cells; meanwhile, in the fourth larval instar, the pedicel is without a lumen and consists of two rows of discoidal cells which are arranged as a short column between the follicle and calyx. The mean volume of the follicle in the fourth larval instar is 9.078?±?3.0178 ?m(3), meanwhile in the pupal stage being 12.051?±?2.427 ?m(3). The germarium (G) decreases in size in the pupal stage and contains a group of cells from which the oogonia differentiate, follicular cells which are similar to trophocytes, undifferentiated into one oocyte (O), which will develop into an egg and it is statistically the smallest one measured (0.058?±?0.0041 ?m(3), 0.303?±?0.0086 ?m(3)) in fourth larval instar and pupal stage, respectively as compared to the others within the follicle which will be accompanied as nurse cells (NC). The follicle is enclosed by a mononuclear flattened cells (follicular membrane), which have distinct boundaries. The vitellarium is differentiated into primary (F1) and secondary follicles (F2) in the pupal stage. The Golgi apparatus (GA) appears as discrete bits which are restricted to the perinuclear zone. The mitochondria (M) in the fourth larval instar are in the form of granules and short rods. They are perinuclearly distributed, forming a ring that surrounds the comparatively large nucleus. In the pupal stage, a similar condition to that described for the larva is observed, but with an increase in size and numbers, due to breaking up of rods into granules. PMID:25241910

  11. [The mosquito-borne viruses in Europe].

    PubMed

    Rossati, Antonella; Bargiacchi, Olivia; Kroumova, Vesselina; Garavelli, Pietro Luigi

    2015-03-01

    Epidemiologic changes of vector-borne diseases in recent years have multiple causes, including climate change. There are about 3500 species of mosquitoes worldwide, three-quarters of which live in tropical and subtropical wetlands. Main viruses transmitted by mosquitoes in Europe belong to the genus Flavivirus; some of them have been recently reported in Italy (Usutu and Japanese encephalitis virus), while others have been circulating for years and autochthonous transmission has been documented (West Nile virus). Mosquito-borne viruses can be classified according to the vector (Aedes or Culex), which, in turn, is associated with different vertebrate host and pathology. The Flavivirus transmitted by Culex have birds as a reservoir and can cause meningoencephalitis, while viruses transmitted by Aedes have primates as reservoir, do not have neurotropism and mainly cause hemorrhagic diseases. Other arbovirus, potentially responsible of epidemics, are the Chikungunya virus (Alphavirus family), introduced for the first time in Europe in 2007, and the virus of Rift Valley fever (Phlebovirus family). The spread in non-endemic areas of vector-born diseases have highlighted the importance of surveillance systems and vector control strategies. PMID:25805223

  12. Main Vector Adaptation: A CMA Variant with Linear Time and Space Complexity

    E-print Network

    Zell, Andreas

    Main Vector Adaptation: A CMA Variant with Linear Time and Space Complexity Jan Poland University T The covariance matrix adaptation (CMA) is one of the most powerful self adapta- tion mechanisms for Evolution Strategies. However, for increasing search space dimen- sion N, the performance declines, since the CMA has

  13. Collagen-binding protein, Aegyptin, regulates probing time and blood feeding success in the dengue vector mosquito, Aedes aegypti

    PubMed Central

    Chagas, Andrezza Campos; Ramirez, José Luis; Jasinskiene, Nijole; James, Anthony A.; Ribeiro, José M. C.; Marinotti, Osvaldo; Calvo, Eric

    2014-01-01

    Mosquito salivary glands have important roles in blood feeding and pathogen transmission. However, the biological relevance of many salivary components has yet to be determined. Aegyptin, a secreted salivary protein from Aedes aegypti, binds collagen and inhibits platelet aggregation and adhesion. We used a transgenic approach to study the relevance of Aegyptin in mosquito blood feeding. Aedes aegypti manipulated genetically to express gene-specific inverted-repeat RNA sequences exhibited significant reductions in Aegyptin mRNA accumulation (85–87%) and protein levels (>80-fold) in female mosquito salivary glands. Transgenic mosquitoes had longer probing times (78–300 s, P < 0.0001) when feeding on mice compared with controls (15–56 s), feeding success was reduced, and those feeding took smaller blood meals. However, no differences in feeding success or blood meal size were found in membrane feeding experiments using defibrinated human blood. Salivary gland extracts from transgenic mosquitoes failed to inhibit collagen-induced platelet aggregation in vitro. Reductions of Aegyptin did not affect salivary ADP-induced platelet aggregation inhibition or disturb anticlotting activities. Our results demonstrate the relevance of Aegyptin for A. aegypti blood feeding, providing further support for the hypothesis that platelet aggregation inhibition is a vital salivary function in blood feeding arthropods. It has been suggested that the multiple mosquito salivary components mediating platelet aggregation (i.e., Aegyptin, apyrase, D7) represent functional redundancy. Our findings do not support this hypothesis; instead, they indicate that multiple salivary components work synergistically and are necessary to achieve maximum blood feeding efficiency. PMID:24778255

  14. Influence of Urban Landscapes on Population Dynamics in a Short-Distance Migrant Mosquito: Evidence for the Dengue Vector Aedes aegypti

    PubMed Central

    Hemme, Ryan R.; Thomas, Clayton L.; Chadee, Dave D.; Severson, David W.

    2010-01-01

    Background Dengue viruses are endemic across most tropical and subtropical regions. Because no proven vaccines are available, dengue prevention is primarily accomplished through controlling the mosquito vector Aedes aegypti. While dispersal distance is generally believed to be ?100 m, patterns of dispersion may vary in urban areas due to landscape features acting as barriers or corridors to dispersal. Anthropogenic features ultimately affect the flow of genes affecting vector competence and insecticide resistance. Therefore, a thorough understanding of what parameters impact dispersal is essential for efficient implementation of any mosquito population suppression program. Population replacement and genetic control strategies currently under consideration are also dependent upon a thorough understanding of mosquito dispersal in urban settings. Methodology and Principal Findings We examined the effect of a major highway on dispersal patterns over a 2 year period. A. aegypti larvae were collected on the east and west sides of Uriah Butler Highway (UBH) to examine any effect UBH may have on the observed population structure in the Charlieville neighborhood in Trinidad, West Indies. A panel of nine microsatellites, two SNPs and a 710 bp sequence of mtDNA cytochrome oxidase subunit 1 (CO1) were used for the molecular analyses of the samples. Three CO1 haplotypes were identified, one of which was only found on the east side of the road in 2006 and 2007. AMOVA using mtCO1 and nuclear markers revealed significant differentiation between the east- and west-side collections. Conclusion and Significance Our results indicate that anthropogenic barriers to A. aegypti dispersal exist in urban environments and should be considered when implementing control programs during dengue outbreaks and population suppression or replacement programs. PMID:20300516

  15. Population genetic structure of the dengue mosquito Aedes aegypti in Venezuela

    Microsoft Academic Search

    Flor Herrera; Ludmel Urdaneta; José Rivero; Normig Zoghbi; Johanny Ruiz; Gabriela Carrasquel; José Antonio Martínez; Martha Pernalete; Patricia Villegas; Ana Montoya; Yasmin Rubio-Palis; Elina Rojas

    2006-01-01

    The mosquito Aedes aegypti is the main vector of dengue in Venezuela. The genetic structure of this vector was investigated in 24 samples collected from eight geographic regions separated by up to 1160 km. We examined the distribution of a 359-basepair region of the NADH dehydrogenase subunit 4 mitochondrial gene among 1144 Ae. aegypti from eight collections. This gene was

  16. Heritability and adaptive phenotypic plasticity of adult body size in the mosquito Aedes aegypti with implications for dengue vector competence

    E-print Network

    Severson, David

    Heritability and adaptive phenotypic plasticity of adult body size in the mosquito Aedes aegypti environmental conditions in the context of a heteroge- neous environment (Newman, 1992). Developmental; Colinet et al., 2007; Kasumovic et al., 2009). Species with an aquatic larval period are of particular

  17. Understanding the spatial and temporal distribution of potential mosquito vectors of Rift Valley fever in the U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rift Valley fever (RVF) is a mosquito-borne zoonotic hemorrhagic viral disease confined primarily to sub-Saharan Africa. In RVF endemic regions human and livestock populations suffer prominent health and economic impacts during RVF outbreaks. RVF virus is listed as an overlap Select Agent by both ...

  18. Vol. 36, no. 1 Journal of Vector Ecology 213 Implications of Plasmodium parasite infected mosquitoes on an insular avifauna

    E-print Network

    Sehgal, Ravinder

    mosquitoes on an insular avifauna: the case of Socorro Island, México Jenny S. Carlson1 , Juan E. Martínez to the avifauna of Socorro Island, México, we surveyed for Plasmodium isolates from 1,300 resident field the Hawaiian archipelago, populations of naïve endemic avifauna are reported to have declined after exposure

  19. An affordable, quality-assured community-based system for high-resolution entomological surveillance of vector mosquitoes that reflects human malaria infection risk patterns

    PubMed Central

    2012-01-01

    Background More sensitive and scalable entomological surveillance tools are required to monitor low levels of transmission that are increasingly common across the tropics, particularly where vector control has been successful. A large-scale larviciding programme in urban Dar es Salaam, Tanzania is supported by a community-based (CB) system for trapping adult mosquito densities to monitor programme performance. Methodology An intensive and extensive CB system for routine, longitudinal, programmatic surveillance of malaria vectors and other mosquitoes using the Ifakara Tent Trap (ITT-C) was developed in Urban Dar es Salaam, Tanzania, and validated by comparison with quality assurance (QA) surveys using either ITT-C or human landing catches (HLC), as well as a cross-sectional survey of malaria parasite prevalence in the same housing compounds. Results Community-based ITT-C had much lower sensitivity per person-night of sampling than HLC (Relative Rate (RR) [95% Confidence Interval (CI)]?=?0.079 [0.051, 0.121], P?vectors caught) and cost-effective (153US$ versus 187US$ per An. gambiae caught) because it allowed more spatially extensive and temporally intensive sampling (4284 versus 335 trap nights distributed over 615 versus 240 locations with a mean number of samples per year of 143 versus 141). Despite the very low vectors densities (Annual estimate of about 170 An gambiae s.l bites per person per year), CB-ITT was the only entomological predictor of parasite infection risk (Odds Ratio [95% CI]?=?4.43[3.027,7. 454] per An. gambiae or Anopheles funestus caught per night, P =0.0373). Discussion and conclusion CB trapping approaches could be improved with more sensitive traps, but already offer a practical, safe and affordable system for routine programmatic mosquito surveillance and clusters could be distributed across entire countries by adapting the sample submission and quality assurance procedures accordingly. PMID:22624853

  20. Use of Remote Sensing Surveillance to Monitor Environmental Parameters Associated with Mosquito Abundance and Vector-borne Diseases

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Lymphatic filariasis persists as a major cause of clinical morbidity and a significant impediment to socioeconomic development in various parts of the world including Egypt. In Egypt, filariasis has been endemic since time immemorial. Early epidemiologic studies identified Culex pipiens L. as the main vector of the disease and also showed that the geographic distribution of the disease is highly focal and concentrated in lower Egypt. Between 1950 and 1965, a large scale filariasis control program was carried out by the Egyptian Ministry of Health (EMOH) in the endemic areas. Control efforts led to a steady decrease of the disease in areas of the country previously identified as endemic. However, spot surveys conducted in various parts of the Nile Delta during the 1970's and 1980's revealed that the downward trend of the disease had stopped and that the prevalence and intensity of microfilaraemia had increased.

  1. Chikungunya A mosquito-borne disease

    E-print Network

    Florida, University of

    species are present in Florida · Aedes aegypti · Also called the Yellow Fever Mosquito · Aedes albopictus #12;Chikungunya Vector: Aedes aegypti, the Yellow Fever Mosquito #12;Larval habitats of container transmitted by mosquitoes · It is also called "contorted fever" and "that which bends up" · The virus

  2. Measurement of landing mosquito density on humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In conventional vector surveillance systems, adult mosquito density and the rate of human-mosquito contact is estimated from the mosquito numbers captured in mechanical traps. However, the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental ...

  3. Prevalence and distribution of pox-like lesions, avian malaria, and mosquito vectors in Kipahulu valley, Haleakala National Park, Hawai'i, USA

    USGS Publications Warehouse

    Aruch, Samuel; Atkinson, Carter T.; Savage, Amy F.; Lapointe, Dennis

    2007-01-01

    We determined prevalence and altitudinal distribution of introduced avian malarial infections (Plasmodium relictum) and pox-like lesions (Avipoxvirus) in forest birds from K?pahulu Valley, Haleakal? National Park, on the island of Maui, and we identified primary larval habitat for the mosquito vector of this disease. This intensively managed wilderness area and scientific reserve is one of the most pristine areas of native forest remaining in the state of Hawai‘i, and it will become increasingly important as a site for restoration and recovery of endangered forest birds. Overall prevalence of malarial infections in the valley was 8% (11/133) in native species and 4% (4/101) in nonnative passerines; prevalence was lower than reported for comparable elevations and habitats elsewhere in the state. Infections occurred primarily in ‘Apapane (Himatione sanguinea) and Hawai‘i ‘Amakihi (Hemignathus virens) at elevations below 1,400 m. Pox-like lesions were detected in only two Hawai‘i ‘Amakihi (2%; 2/94) at elevations below 950 m. We did not detect malaria or pox in birds caught at 1,400 m in upper reaches of the valley. Adult mosquitoes (Culex quinquefasciatus) were captured at four sites at elevations of 640, 760, 915, and 975 m, respectively. Culex quinquefasciatus larvae were found only in rock holes along intermittent tributaries of the two largest streams in the valley, but not in standing surface water, pig wallows, ground pools, tree cavities, and tree fern cavities. Mosquito populations in the valley are low, and they are probably influenced by periods of high rainfall that flush stream systems.

  4. Prevalence and distribution of pox-like lesions, avian malaria, and mosquito vectors in Kipahulu Valley, Haleakala National Park, Hawai'i, USA.

    PubMed

    Aruch, Samuel; Atkinson, Carter T; Savage, Amy F; Lapointe, Dennis A

    2007-10-01

    We determined prevalence and altitudinal distribution of introduced avian malarial infections (Plasmodium relictum) and pox-like lesions (Avipoxvirus) in forest birds from Kipahulu Valley, Haleakal? National Park, on the island of Maui, and we identified primary larval habitat for the mosquito vector of this disease. This intensively managed wilderness area and scientific reserve is one of the most pristine areas of native forest remaining in the state of Hawai'i, and it will become increasingly important as a site for restoration and recovery of endangered forest birds. Overall prevalence of malarial infections in the valley was 8% (11/133) in native species and 4% (4/101) in nonnative passerines; prevalence was lower than reported for comparable elevations and habitats elsewhere in the state. Infections occurred primarily in 'Apapane (Himatione sanguinea) and Hawai'i 'Amakihi (Hemignathus virens) at elevations below 1,400 m. Pox-like lesions were detected in only two Hawai'i 'Amakihi (2%; 2/94) at elevations below 950 m. We did not detect malaria or pox in birds caught at 1,400 m in upper reaches of the valley. Adult mosquitoes (Culex quinquefasciatus) were captured at four sites at elevations of 640, 760, 915, and 975 m, respectively. Culex quinquefasciatus larvae were found only in rock holes along intermittent tributaries of the two largest streams in the valley, but not in standing surface water, pig wallows, ground pools, tree cavities, and tree fern cavities. Mosquito populations in the valley are low, and they are probably influenced by periods of high rainfall that flush stream systems. PMID:17984251

  5. Using a new odour-baited device to explore options for luring and killing outdoor-biting malaria vectors: a report on design and field evaluation of the Mosquito Landing Box

    PubMed Central

    2013-01-01

    Background Mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. Outdoor tools may therefore complement current indoor measures and improve control. We developed and evaluated a prototype mosquito control device, the ‘Mosquito Landing Box’ (MLB), which is baited with human odours and treated with mosquitocidal agents. The findings are used to explore technical options and challenges relevant to luring and killing outdoor-biting malaria vectors in endemic settings. Methods Field experiments were conducted in Tanzania to assess if wild host-seeking mosquitoes 1) visited the MLBs, 2) stayed long or left shortly after arrival at the device, 3) visited the devices at times when humans were also outdoors, and 4) could be killed by contaminants applied on the devices. Odours suctioned from volunteer-occupied tents were also evaluated as a potential low-cost bait, by comparing baited and unbaited MLBs. Results There were significantly more Anopheles arabiensis, An. funestus, Culex and Mansonia mosquitoes visiting baited MLB than unbaited controls (P?0.028). Increasing sampling frequency from every 120 min to 60 and 30 min led to an increase in vector catches of up to 3.6 fold (P?0.002), indicating that many mosquitoes visited the device but left shortly afterwards. Outdoor host-seeking activity of malaria vectors peaked between 7:30 and 10:30pm, and between 4:30 and 6:00am, matching durations when locals were also outdoors. Maximum mortality of mosquitoes visiting MLBs sprayed or painted with formulations of candidate mosquitocidal agent (pirimiphos-methyl) was 51%. Odours from volunteer occupied tents attracted significantly more mosquitoes to MLBs than controls (P<0.001). Conclusion While odour-baited devices such as the MLBs clearly have potential against outdoor-biting mosquitoes in communities where LLINs are used, candidate contaminants must be those that are effective at ultra-low doses even after short contact periods, since important vector species such as An. arabiensis make only brief visits to such devices. Natural human odours suctioned from occupied dwellings could constitute affordable sources of attractants to supplement odour baits for the devices. The killing agents used should be environmentally safe, long lasting, and have different modes of action (other than pyrethroids as used on LLINs), to curb the risk of physiological insecticide resistance. PMID:23642306

  6. In-silico homology modeling of three isoforms of insect defensins from the dengue vector mosquito, Aedes aegypti (Linn., 1762)

    Microsoft Academic Search

    K. J. Dhananjeyan; R. Sivaperumal; R. Paramasivan; V. Thenmozhi; B. K. Tyagi

    2009-01-01

    Dengue is a serious public health problem in tropical and subtropical countries. It is caused by any of the four serologically\\u000a distinct dengue viruses, namely DENV1–4. The viruses are transmitted by Aedes mosquitoes. Understanding various defence mechanisms\\u000a of insects has become a prime area of research worldwide. In insects, the first line of defence against invading pathogens\\u000a includes cellular mechanisms

  7. Evaluation of attractive toxic sugar bait (ATSB)-barrier for control of vector and nuisance mosquitoes and its effect on non-target organisms in sub-tropical environments in Florida.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the efficacy of attractive toxic sugar baits (ATSB) in the laboratory and the field with the Environmental Protection Agency exempt active ingredient eugenol against vector and nuisance mosquitoes. In the laboratory, eugenol combined in attractive sugar bait (ASB) solution provided high...

  8. Identity and transfer of male reproductive gland proteins of the dengue vector mosquito, Aedes aegypti: potential tools for control of female feeding and reproduction

    PubMed Central

    Sirot, Laura K.; Poulson, Rebecca L.; McKenna, M. Caitlin; Girnary, Hussein; Wolfner, Mariana F.; Harrington, Laura C.

    2009-01-01

    Male reproductive gland proteins (mRGPs) impact the physiology and/or behavior of mated females in a broad range of organisms. We sought to identify mRGPs of the yellow fever mosquito, Aedes aegypti, the primary vector of dengue and yellow fever viruses. Earlier studies with Ae. aegypti demonstrated that “matrone” (a partially purified male reproductive accessory gland substance) or male accessory gland fluid injected into virgin female Ae. aegypti affect female sexual refractoriness, blood feeding and digestion, flight, ovarian development, and oviposition. Using bioinformatic comparisons to Drosophila melanogaster accessory gland proteins and mass spectrometry of proteins from Ae. aegypti male accessory glands and ejaculatory ducts (AG/ED) and female reproductive tracts, we identified 63 new putative Ae. aegypti mRGPs. Twenty-one of these proteins were found in the reproductive tract of mated females, but not of virgin females, suggesting that they are transferred from males to females during mating. Most of the putative mRGPs fall into the same protein classes as mRGPs in other organisms, although some appear to be evolving rapidly and lack identifiable homologs in Culex pipiens, Anopheles gambiae, and D. melanogaster. Our results identify candidate male-derived molecules that may have an important influence on behavior, survival and reproduction of female mosquitoes. PMID:18207079

  9. Loop-mediated isothermal amplification applied to filarial parasites detection in the mosquito vectors: Dirofilaria immitis as a study model

    Microsoft Academic Search

    Hiroka Aonuma; Aya Yoshimura; Namal Perera; Naoaki Shinzawa; Hironori Bando; Sugao Oshiro; Bryce Nelson; Shinya Fukumoto; Hirotaka Kanuka

    2009-01-01

    BACKGROUND: Despite recent advances in our understanding of the basic biology behind transmission of zoonotic infectious diseases harbored by arthropod vectors these diseases remain threatening public health concerns. For effective control of vector and treatment, precise sampling indicating the prevalence of such diseases is essential. With an aim to develop a quick and simple method to survey zoonotic pathogen-transmitting vectors,

  10. The value of long-term mosquito surveillance data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most important activities performed by mosquito and vector control agencies is mosquito population surveillance. Mosquito population surveillance data are the written results of adult or larval mosquito sampling, recorded and preserved on paper forms or entered into electronic spreadshee...

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

    PubMed

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

    2014-10-01

    Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known as Andean and non-Andean chromosomal groups, that are highly differentiated by the amount of heterochromatin and genome size. Analyses with nuclear and mitochondrial sequences are not conclusive about resolving the origin and spread of T. infestans. The present paper includes the analyses of karyotypes, heterochromatin distribution and chromosomal mapping of the major ribosomal cluster (45S rDNA) to specimens throughout the distribution range of this species, including pyrethroid-resistant populations. A total of 417 specimens from seven different countries were analyzed. We show an unusual wide rDNA variability related to number and chromosomal position of the ribosomal genes, never before reported in species with holocentric chromosomes. Considering the chromosomal groups previously described, the ribosomal patterns are associated with a particular geographic distribution. Our results reveal that the differentiation process between both T. infestans chromosomal groups has involved significant genomic reorganization of essential coding sequences, besides the changes in heterochromatin and genomic size previously reported. The chromosomal markers also allowed us to detect the existence of a hybrid zone occupied by individuals derived from crosses between both chromosomal groups. Our genetic studies support the hypothesis of an Andean origin for T. infestans, and suggest that pyrethroid-resistant populations from the Argentinean-Bolivian border are most likely the result of recent secondary contact between both lineages. We suggest that vector control programs should make a greater effort in the entomological surveillance of those regions with both chromosomal groups to avoid rapid emergence of resistant individuals. PMID:25017654

  12. Avian host and mosquito (Diptera: Culicidae) vector competence determine the efficiency of West Nile and St. Louis encephalitis virus transmission.

    PubMed

    Reisen, W K; Fang, Y; Martinez, V M

    2005-05-01

    The ability of the invading NY99 strain of West Nile virus (WNV) to elicit an elevated viremia response in California passerine birds was critical for the effective infection of Culex mosquitoes. Of the bird species tested, Western scrub jays, Aphelocoma coerulescens, produced the highest viremia response, followed by house finches, Carpodacus mexicanus, and house sparrows, Passer domesticus. Most likely, few mourning, Zenaidura macroura, or common ground, Columbina passerine, doves and no California quail, Callipepla californica, or chickens would infect blood-feeding Culex mosquitoes. All Western scrub jays and most house finches succumbed to infection. All avian hosts produced a lower viremia response and survived after infection with an endemic strain of St. Louis encephalitis virus. Culex species varied in their susceptibility to infection with both viruses, with Culex stigmatosoma Dyar generally most susceptible, followed by Culex tarsalis Coquillett, and then Culex p. quinquefasciatus Say. Populations within Culex species varied markedly in their susceptibility, perhaps contributing to the focality of WNV amplification. Transmitting female Cx. tarsalis expectorated from six to 3,777 plaque-forming units (PFU) of WNV during transmission trials, thereby exposing avian hosts to a wide range of infectious doses. Highly susceptible house finches and moderately susceptible mourning doves were infected by subcutaneous inoculation with decreasing concentrations of WNV ranging from 15,800 to <0.3 PFU. All birds became infected and produced comparable peak viremias on days 2-3 postinoculation; however, the rise in viremia titer and onset of the acute phase of infection occurred earliest in birds inoculated with the highest doses. WNV virulence in birds seemed critical in establishing elevated viremias necessary to efficiently infect blood feeding Culex mosquitoes. PMID:15962789

  13. Behavioural and insecticidal effects of organophosphate-, carbamate- and pyrethroid-treated mosquito nets against African malaria vectors.

    PubMed

    Malima, R C; Oxborough, R M; Tungu, P K; Maxwell, C; Lyimo, I; Mwingira, V; Mosha, F W; Matowo, J; Magesa, S M; Rowland, M W

    2009-12-01

    Three insecticides - the pyrethroid deltamethrin, the carbamate carbosulfan and the organophosphate chlorpyrifos-methyl - were tested on mosquito nets in experimental huts to determine their potential for introduction as malaria control measures. Their behavioural effects and efficacy were examined in Anopheles gambiae Giles s.s. (Diptera: Culicidae) and Anopheles funestus Giles s.s. in Muheza, Tanzania, and in Anopheles arabiensis Patton and Culex quinquefasciatus Say in Moshi, Tanzania. A standardized dosage of 25 mg/m(2) plus high dosages of carbosulfan (50 mg/m(2), 100 mg/m(2) and 200 mg/m(2)) and chlorpyrifos-methyl (100 mg/m(2)) were used to compare the three types of insecticide. At 25 mg/m(2), the rank order of the insecticides for insecticide-induced mortality in wild An. gambiae and An. funestus was, respectively, carbosulfan (88%, 86%) > deltamethrin (79%, 78%) > chlorpyrifos-methyl (35%, 53%). The rank order of the insecticides for blood-feeding inhibition (reduction in the number of blood-fed mosquitoes compared with control) in wild An. gambiae and An. funestus was deltamethrin > chlorpyrifos-methyl > carbosulfan. Carbosulfan was particularly toxic to endophilic anophelines at 200 mg/m(2), killing 100% of An. gambiae and 98% of An. funestus that entered the huts. It was less effective against the more exophilic An. arabiensis (67% mortality) and carbamate-resistant Cx quinquefasciatus (36% mortality). Carbosulfan deterred anophelines from entering huts, but did not deter carbamate-resistant Cx quinquefasciatus. Deltamethrin reduced the proportion of insects engaged in blood-feeding, probably as a consequence of contact irritancy, whereas carbosulfan seemed to provide personal protection through deterred entry or perhaps a spatial repellent action. Any deployment of carbosulfan as an individual treatment on nets should be carried out on a large scale to reduce the risk of diverting mosquitoes to unprotected individuals. Chlorpyrifos-methyl was inferior to deltamethrin in terms of mortality and blood-feeding inhibition and would be better deployed on a net in combination with a pyrethroid to control insecticide-resistant mosquitoes. PMID:19941597

  14. Comparison of different trapping methods for surveillance of mosquito vectors of West Nile virus in Rhône Delta, France.

    PubMed

    L'Ambert, Grégory; Ferré, Jean-Baptiste; Schaffner, Francis; Fontenille, Didier

    2012-12-01

    Five trapping methods were compared for monitoring potential vectors of the West Nile virus in four areas in the Camargue Plain of France: carbon dioxide traps, bird-baited traps, gravid traps, resting boxes, and human landing catches. A total of 73,721 specimens, representing 14 species, was trapped in 2006. Results showed significant differences in species and abundance between the type of traps. Many more specimens were collected using CO(2) traps than any other method, with an average of 212 specimens per night per trap (p<0.05). Culex pipiens was the most abundant species collected (36.8% of total with CO(2) traps), followed by Aedes caspius (22.7%), Anopheles hyrcanus (18.3%), Culex modestus (18.3%), and Aedes detritus (3.2%). Bird-baited traps captured only eight specimens per night per trap on average, mainly Cx. pipiens (89.9%). The species collected and their abundance are influenced by the trap location, at ground or canopy level. Culex pipiens was twice as abundant in the canopy as on the ground, whereas it was the opposite for Ae. caspius, An. hyrcanus, and Ae. detritus. Culex modestus was equally abundant at both levels. Resting boxes and gravid traps were much less efficient, capturing around 0.3 specimens per night per trap. Results are discussed in relation to West Nile virus surveillance. PMID:23181848

  15. Competitive Reduction by Satyrization? Evidence for Interspecific Mating in Nature and Asymmetric Reproductive Competition between Invasive Mosquito Vectors

    PubMed Central

    Tripet, Frederic; Lounibos, L. Philip; Robbins, Dannielle; Moran, Jenny; Nishimura, Naoya; Blosser, Erik M.

    2011-01-01

    Upon mating, male mosquitoes transfer accessory gland proteins (Acps) that induce refractoriness to further mating in females. This can also occur because of cross-insemination by males of related species, a process known as mating interference (satyrization). This mechanism could explain the competitive displacement of resident Aedes aegypti by the invasive Aedes albopictus where they co-occur. We tested this hypothesis in mosquito populations in Florida. A new polymerase chain reaction species diagnostic applied to sperm dissected from 304 field-collected females revealed bidirectional cross-mating in five (1.6%) individuals. Cross-injections of females with Acps showed that Ae. albopictus males induced monogamy in heterospecific females but not Ae. aegypti males. Despite its low frequency in the areas under study, the first evidence of cross-mating in nature and the asymmetric effect of Acps on mating suggest that satyrization may have initially contributed to the observed competitive reduction of Ae. aegypti by invasive Ae. albopictus in many areas. PMID:21813845

  16. Anopheles sinensis mosquito insecticide resistance: comparison of three mosquito sample collection and preparation methods and mosquito age in resistance measurements

    PubMed Central

    2014-01-01

    Background Insecticide resistance monitoring in malaria mosquitoes is essential for guiding the rational use of insecticides in vector control programs. Resistance bioassay is the first step for insecticide monitoring and it lays an important foundation for molecular examination of resistance mechanisms. In the literature, various mosquito sample collection and preparation methods have been used, but how mosquito sample collection and preparation methods affect insecticide susceptibility bioassay results is largely unknown. The objectives of this study were to determine whether mosquito sample collection and preparation methods affected bioassay results, which may cause incorrect classification of mosquito resistance status. Methods The study was conducted in Anopheles sinensis mosquitoes in two study sites in central China. Three mosquito sample collection and preparation methods were compared for insecticide susceptibility, kdr frequencies and metabolic enzyme activities: 1) adult mosquitoes collected from the field; 2) F1 adults from field collected, blood-fed mosquitoes; and 3) adult mosquitoes reared from field collected larvae. Results Mosquito sample collection and preparation methods significantly affected mortality rates in the standard WHO tube resistance bioassay. Mortality rate of field-collected female adults was 10-15% higher than in mosquitoes reared from field-collected larvae and F1 adults from field collected blood-fed females. This pattern was consistent in mosquitoes from the two study sites. High kdr mutation frequency (85-95%) with L1014F allele as the predominant mutation was found in our study populations. Field-collected female adults consistently exhibited the highest monooxygenase and GST activities. The higher mortality rate observed in the field-collected female mosquitoes may have been caused by a mixture of mosquitoes of different ages, as older mosquitoes were more susceptible to deltamethrin than younger mosquitoes. Conclusions Female adults reared from field-collected larvae in resistance bioassays are recommended to minimize the effect of confounding factors such as mosquito age and blood feeding status so that more reliable and reproducible mortality may be obtained. PMID:24472598

  17. The Apyrase gene of the vector mosquito, Aedes aegypti, is expressed specifically in the adult female salivary glands.

    PubMed

    Smartt, C T; Kim, A P; Grossman, G L; James, A A

    1995-11-01

    The yellow fever mosquito, Aedes aegypti, expresses a gene, Apyrase (Apy), that encodes an ATP-diphosphohydrolase. The product of this gene is a secreted enzyme that facilitates hematophagy by preventing platelet aggregation in the host. Apy gene expression is limited to the cells of the distal-lateral and medial lobes of the adult female salivary glands. Apyrase protein levels, detectable by antibodies, peak in the salivary glands about 4 days after adult emergence and remain high after a blood meal. Primary sequence analysis of a genomic clone encoding apyrase reveals a unique TAAATA sequence and seven introns, as well as other conserved features of eukaryotic genes. The temporal, sex- and tissue-specific expression of the Apy gene is consistent with its role as encoding a platelet anti-aggregation factor that functions to facilitate hematophagy and decrease probing time. PMID:7498420

  18. Larvicidal potential of wild mustard (Cleome viscosa) and gokhru (Tribulus terrestris) against mosquito vectors in the semi-arid region of Western Rajasthan.

    PubMed

    Bansal, S K; Singh, Karam V; Sharma, Sapna

    2014-03-01

    Cleome viscosa L. (Family: Capparaceae) commonly known as Tickweed or wild mustard and Tribulus terrestris L. (Family: Zygophyllaceae) commonly known as Gokhru, growing wildly in the desert areas in the monsoon and post monsoon season, are of great medicinal importance. Comparative larvicidal efficacy of the extracts from seeds of C. viscosa and fruits and leaves of T. terrestris was evaluated against 3rd or early 4th stage larvae of Anopheles stephensi (Liston), Aedes aegypti (Linnaeus) and Culex quinquefasciatus (Say) in different organic solvents. 24 and 48 hr LC50 and LC90 values along with their 95% fiducial limits, regression equation, chi-square (chi2)/ heterogeneity of the response was determined by log probit regression analysis. The 24 hr LC50 values as determined for seeds of C. viscosa were 144.1, 99.5 and 127.1 (methanol); 106.3, 138.9 and 118.5 (acetone) and 166.4, 162.5 and 301.9 mg l(-1) (petroleum ether extracts) for all the three mosquito species respectively showing that methanol and acetone extracts were a little bit more effective than the petroleum ether extracts. Experiments were carried out with fruits and leaves of T. terrestris with all the solvents and mosquito species. The 24 hr LC50 values, as determined for fruits of T. terrestris were 70.8, 103.4 and 268.2 (methanol); 74.0,120.5 and 132.0 (acetone) and 73.8,113.5 and 137.4 mg l(-1) (petroleum ether extracts) while the 24 hr LC50 values for leaves were 124.3, 196.8 and 246.5 (methanol); 163.4, 196.9 and 224.3 (acetone) and 135.8, 176.8 and 185.9 mg l(-1) (petroleum ether extracts) for all the three mosquito species respectively. The results clearly indicate that fruit extracts of T. terrestris were more effective as compared to leaves extracts in the three solvents tested. Larvae of An. stephensi were found more sensitive to both fruit and leaves extracts of T. terrestris followed by larvae of Ae. aegypti and Cx. quinquefasciatus. Extracts from the seeds of C. viscosa were found less effective as compared to the fruit extracts of T. terrestris indicating that active larvicidal principle may be present in the fruits of this plant species. The studywould be of great importance while formulating the control strategy, for vectors of malaria, dengue and lymphatic filariasis, based on alternative plant based insecticides in this semi-arid region. PMID:24665757

  19. Factors influencing stakeholders attitudes toward genetically modified aedes mosquito.

    PubMed

    Amin, Latifah; Hashim, Hasrizul

    2015-06-01

    Dengue fever is a debilitating and infectious disease that could be life-threatening. It is caused by the dengue virus which affects millions of people in the tropical area. Currently, there is no cure for the disease as there is no vaccine available. Thus, prevention of the vector population using conventional methods is by far the main strategy but has been found ineffective. A genetically modified (GM) mosquito is among the favoured alternatives to curb dengue fever in Malaysia. Past studies have shown that development and diffusion of gene technology products depends heavily upon public acceptance. The purpose of this study is to identify the relevant factors influencing stakeholders' attitudes toward the GM Aedes mosquito and to analyse the relationships between all the factors using the structural equation model. A survey was carried out on 509 respondents from various stakeholder groups in the Klang Valley region of Malaysia. Results of the survey have confirmed that public perception towards complex issues such as gene technology should be seen as a multi-faceted process. The perceived benefit-perceived risk balance is very important in determining the most predominant predictor of attitudes toward a GM mosquito. In this study the stakeholders perceived the benefit of the GM mosquito as outweighing its risk, translating perceived benefit as the most important direct predictor of attitudes toward the GM mosquito. Trust in key players has a direct influence on attitudes toward the GM mosquito while moral concern exhibited an indirect influence through perceived benefits. Other factors such as attitudes toward technology and nature were also indirect predictors of attitudes toward the GM mosquito while religiosity and engagement did not exhibited any significant roles. The research findings serve as a useful database to understand public acceptance and the social construct of public attitudes towards the GM mosquito to combat dengue. PMID:24906652

  20. Modeling Mosquito Distribution. Impact of the Landscape

    NASA Astrophysics Data System (ADS)

    Dumont, Y.

    2011-09-01

    In order to use efficiently vector control tools, like insecticides, and mechanical control, it is necessary to provide mosquito density estimate and mosquito distribution, taking into account the environment and entomological knowledges. Mosquito dispersal modeling, together with a compartmental approach, leads to a quasilinear parabolic system. Using the time splitting approach and appropriate numerical methods for each operator, we construct a reliable numerical scheme. Considering various landscapes, we show that the environment can have a strong influence on mosquito distribution and, thus, in the efficiency or not of vector control.

  1. 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?

    PubMed Central

    Mocellin, Márcio Goulart; Simões, Taynãna César; do Nascimento, Teresa Fernandes Silva; Teixeira, Maria Lucia França; Lounibos, Leon Philip; de Oliveira, Ricardo Lourenço

    2012-01-01

    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. PMID:20140379

  2. Impact of larviciding with a Bacillus thuringiensis israelensis formulation, VectoBac WG, on dengue mosquito vectors in a dengue endemic site in Selangor State, Malaysia.

    PubMed

    Lee, H L; Chen, C D; Masri, S Mohd; Chiang, Y F; Chooi, K H; Benjamin, S

    2008-07-01

    The field bioefficacy of a wettable granule (WG) formulation of Bacillus thuringiensis israelensis (Bti), VectoBac WG (Bti strain AM65-52) against dengue vectors, Aedes aegypti and Ae albopictus; was evaluated in a suburban residential area (TST) and in a temporary settlement site (KB) in the state of Selangor, Malaysia. Pre-control ovitrap surveillance of the trial sites indicated a high population of both types of Aedes mosquitoes. The populations were monitored continuously by weekly ovitrapping. Bti was sprayed biweekly at a dosage of 500 g/ha by using a mist-blower. The spray application was targeted into outdoor larval habitats. If required, Bti formulation was also applied directly into indoor water-holding containers at 8 g/1,000 l. Based on ovitrap surveillance, a significant reduction in Aedes populations was evident 4 weeks after initiating the first Bti treatment. The ovitrap index (OI) and the larvae density decreased drastically in both trial sites. In TST, the indoor OI was significantly reduced from 57.50 +/- 7.50% to 19.13 +/- 5.49% (p<0.05), while the outdoor OI decreased from 38.89 +/- 11.11% to 15.36 +/- 5.93%. In KB, similarly, the OI was significantly reduced by more than half, from 66.66 +/- 6.67% to 30.26 +/- 2.99% (p< 0.05). In all cases, the reduction in OI was paralleled by reduction in larval density. PMID:19058596

  3. Aldehyde oxidase is coamplified with the World's most common Culex mosquito insecticide resistance-associated esterases

    Microsoft Academic Search

    J. Hemingway; M. Coleman; M. Paton; L. McCarroll; A. Vaughan; D. DeSilva

    2000-01-01

    The evolution and spread of insecticide resistance is an important factor in human disease prevention and crop protection. The mosquito Culex quinquefasciatus is the main vector of the disease filariasis and a member of a species complex which is a common biting nuisance worldwide. The common insecticide resist- ance mechanism in this species involves germline amplification of the esterases est

  4. [Detection of flavivirus in mosquitoes (Diptera: Culicidae) from Easter Island-Chile].

    PubMed

    Collao, Ximena; Prado, Lorena; González, Christian; Vásquez, Ana; Araki, Romina; Henríquez, Tuki; Peña M, Cindy

    2015-02-01

    Flaviviruses are arthropod-borne viruses, mainly by mosquitoes of the genera Aedes and Culex (Culicidae) that are detected in tropical and subtropical areas. Main flaviviruses of public health importance are: dengue, West Nile virus, yellow fever, among others. In continental Chile, flaviviruses has not been detected. However, there are indigenous cases of dengue detected in Easter Island since 2002, as the presence of its vector Aedes aegypti. The aim of this study was: To determine diversity of flavivirus mosquitoes present in Easter Island. Thirty pools of mosquitoes collected in Hanga Roa were analyzed; a RT-PCR nested flavivirus was performed. Thirteen positive samples were detected and the amplification products were sequenced, identifying two specific flavivirus Insect, the Cell fusing agent virus and other related viruses Kamiti River. This is the first study in Chile showed the presence of flavivirus in vectors in Easter Island. PMID:25860055

  5. IDENTIFICATION OF CANDIDATE ATTRACTANT COMPOUNDS FROM CHICKEN FEATHERS FOR THE MOSQUITO VECTOR OF THE WEST NILE VIRUS BY GC/MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes are the primary source of many diseases, including yellow fever, malaria, dengue fever, encephalitis and West Nile Virus (WNV). Because the WNV is maintained in nature by the bird-mosquito-bird cycle, identification of odors emitted from avian hosts will aid in the development of better t...

  6. Vector Competence of Eastern and Western Forms of Psorophora columbiae (Diptera: Culicidae) Mosquitoes for Enzootic and Epizootic Venezuelan Equine Encephalitis Virus

    Microsoft Academic Search

    Abelardo C. Moncayo; Gregory Lanzaro; Wenli Kang; Arnoldo Orozco; Armando Ulloa; Juan Arredondo-Jiménez; Scott C. Weaver

    2008-01-01

    Venezuelan equine encephalitis virus (VEEV) continues to circulate enzootically in Mexico with the potential to re-emerge and cause disease in equines and humans in North America. We infected two geographically distinct mosquito populations of eastern Psorophora columbiae form columbiae (Chiapas, Mexico and Texas, United States) and one mosquito population of western Psorophora columbiae form toltecum (California, United States) with epizootic

  7. A review of recent knowledge of the ecology of the main vectors of trypanosomiasis*

    PubMed Central

    Langridge, W. P.; Kernaghan, R. J.; Glover, P. E.

    1963-01-01

    In this survey of recent ecological research on the main vectors of trypanosomiasis in those countries of East, Central and West Africa that are not predominantly French-speaking, the authors, after outlining the distribution of tsetse flies and the type of country in which they occur, discuss the direct and indirect effects of climate on these insects—particularly on their physiological water balance and on pupal fat reserves—and their recent advances into new areas. They review the considerable work that has been done on the resting habits and breeding-sites of different Glossina species, knowledge of which is important for effective control, and research on predators of pupae and adult flies and on the feeding activity of tsetse flies. Means of assessing populations and various factors affecting the size and nutritional status of tsetse flies are also discussed, as is the effect on the fly population of artificial changes in the habitat. Finally, a plea is made for a revision of present methods of land use and stock management, if full advantage is to be taken of achievements in fly control. PMID:13928678

  8. Mosquitos and You! Mosquito Control and Prevention

    E-print Network

    in the Mosquito Life Cycle. Stage 1 Stage 2 Stage 4 Stage 3 Adult Pupa Larva Egg Raft 4 #12;Mosquito Search HIDDEN WORDS MALARIA LARVA EGGRAFT MOSQUITO AFRICA WESTNILE PUPA DENGUE 5 #12;Can you Mosquitos and You! Mosquito Control and Prevention Third, Fourth and Fifth Grades State

  9. Molecular epidemiology of Japanese encephalitis virus in mosquitoes in Taiwan during 2005-2012.

    PubMed

    Su, Chien-Ling; Yang, Cheng-Fen; Teng, Hwa-Jen; Lu, Liang-Chen; Lin, Cheo; Tsai, Kun-Hsien; Chen, Yu-Yu; Chen, Li-Yu; Chang, Shu-Fen; Shu, Pei-Yun

    2014-10-01

    Japanese encephalitis (JE) is a mosquito-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). Pigs and water birds are the main amplifying and maintenance hosts of the virus. In this study, we conducted a JEV survey in mosquitoes captured in pig farms and water bird wetland habitats in Taiwan during 2005 to 2012. A total of 102,633 mosquitoes were collected. Culex tritaeniorhynchus was the most common mosquito species found in the pig farms and wetlands. Among the 26 mosquito species collected, 11 tested positive for JEV by RT-PCR, including Cx. tritaeniorhynchus, Cx. annulus, Anopheles sinensis, Armigeres subalbatus, and Cx. fuscocephala. Among those testing positive, Cx. tritaeniorhynchus was the predominant vector species for the transmission of JEV genotypes I and III in Taiwan. The JEV infection rate was significantly higher in the mosquitoes from the pig farms than those from the wetlands. A phylogenetic analysis of the JEV envelope gene sequences isolated from the captured mosquitoes demonstrated that the predominant JEV genotype has shifted from genotype III to genotype I (GI), providing evidence for transmission cycle maintenance and multiple introductions of the GI strains in Taiwan during 2008 to 2012. This study demonstrates the intense JEV transmission activity in Taiwan, highlights the importance of JE vaccination for controlling the epidemic, and provides valuable information for the assessment of the vaccine's efficacy. PMID:25275652

  10. Susceptibility of mosquitoes to ingested insecticides.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes are important vectors of many diseases of medical and veterinary importance. Control of adult mosquitoes is conventionally through application of aerial sprays, however, there are environmental and health concerns associated with these sprays. One approach for targeted control of mosqui...

  11. Novel Methods for Mosquito Control using RNAi.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The discovery and development of novel insecticides for vector control is a primary focus of toxicology research conducted at the Mosquito and Fly Research Unit, Gainesville, FL. Targeting critical genes/proteins in mosquitoes using RNA interference (RNAi) is being investigated as a method to devel...

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

    Microsoft Academic Search

    Virendra K Dua; Akhilesh C Pandey; Kamaraju Raghavendra; Ashish Gupta; Trilochan Sharma; Aditya P Dash

    2009-01-01

    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

  13. Influence of biofuel crops on mosquito production and oviposition site selection

    E-print Network

    Allan, Brian

    fever mosquito Aedes aegypti and the Asian tiger mosquito Aedes albopictus. Larvae of the two speciesInfluence of biofuel crops on mosquito production and oviposition site selection E P H A N T U S J and Miscanthus) biofuel crops on production and oviposition site selection by two vector mosquitoes, the yellow

  14. Impact of dryland salinity on population dynamics of vector mosquitoes (Diptera: Culicidae) of Ross River virus in inland areas of southwestern Western Australia.

    PubMed

    Jardine, A; Lindsay, M D A; Johansen, C A; Cook, A; Weinstein, P

    2008-11-01

    Clearing of native vegetation for agriculture since European settlement has left 1.047 million ha of southwestern Australia affected by a severe form of environmental degradation called dryland salinity, characterized by secondary soil salinization and waterlogging. This area may expand by a further 1.7-3.4 million ha if current trends continue. Detailed investigations of seasonal of adult and larval mosquito population dynamics were undertaken in the region to test the hypothesis that the development of dryland salinity and waterlogging in inland southwestern Australia has led to a succession of mosquito species and increased Ross River virus (family Togaviridae, genus Alphavirus, RRV) transmission risk. Aedes (Ochlerotatus) camptorhynchus (Thomson) made up >90% of adult mosquito collections in saline regions. Nonmetric multidimensional scaling and generalized estimating equations modeling demonstrated that it was strongly associated with increasing severity of dryland salinity. This article describes the first detailed investigation of the mosquito fauna of inland southwestern Australia, and it is the first description of the influence of secondary soil salinity on mosquito population dynamics. Despite the dominant presence of Ae. camptorhynchus, RRV disease incidence is not currently a significant population health priority in areas affected by dryland salinity. Potential limiting factors include local climatic impacts on the seasonal mosquito population dynamics, vertebrate host distribution and feeding behavior of Ae. camptorhynchus, and the scarce and uneven distribution of the human population in the region. PMID:19058624

  15. [Monitoring of the insecticidal resistance of main malaria vectors in Uzbekistan].

    PubMed

    Zhakhongirov, Sh M; Abdullaev, I T; Ponomarev, I M; Muminov, M S

    2004-01-01

    In the Fergana valley, the sensitivity of Anopheles maculipennis to DDT was moderate (82.5% death rates) and that to carbamate agents (bendiocarb, 43.5%, and propoxur, 13.0%) was decreased. There was its high sensitivity to pyrethroidal insecticides, such as deltamethrin, lambdacigalothrin, and cifluthrin (100% death rates). The population was moderately resistant to carbamates: bendiocarb and propoxur (69.3 and 77.2% death rates, respectively). In the piedmont and mountainous districts of the Surkhandarya Region, A. superpictus is highly sensitive to all tested drugs. In the plain area of the Samarkand Area, the sensitivity of A. maculipennis to the insecticides, such as fenitrothion, propoxur, and permethrin, was 98.3, 92.3, and 97.0% death rates, respectively; the Tashkent, Dzhizak, and Surkhandaryinsk A. pulcherrimus population retained a normal sensitivity to all tested agents (94.4-100% death rates). The diapausing female A. superpictus mosquitoes in the population from the Fergana valley were found to be resistant to DDT (82.8% death rates) and highly resistant to malathion (43.8%), fenitrothion (38.8%), bendiocarb (2.7%), and propoxur (7.0%); the Tashkent and Surkhandaryinsk populations were also considerably resistant to these agents (35.3-89.6% death rates). PMID:15042745

  16. Evidence of Simultaneous Circulation of West Nile and Usutu Viruses in Mosquitoes Sampled in Emilia-Romagna Region (Italy) in 2009

    PubMed Central

    Calzolari, Mattia; Bonilauri, Paolo; Bellini, Romeo; Albieri, Alessandro; Defilippo, Francesco; Maioli, Giulia; Galletti, Giorgio; Gelati, Antoni; Barbieri, Ilaria; Tamba, Marco; Lelli, Davide; Carra, Elena; Cordioli, Paolo; Angelini, Paola; Dottori, Michele

    2010-01-01

    Background In recent years human diseases due to mosquito-borne viruses were increasingly reported in Emilia-Romagna region (Italy), from the chikungunya virus in 2007 to the West Nile virus (WNV) in 2008. An extensive entomological survey was performed in 2009 to establish the presence and distribution of mosquito arboviruses in this region, with particular reference to flaviviruses. Methodology/Principal Findings From May 6 to October 31, a total of 190,516 mosquitoes were sampled in georeferenced stations, grouped in 1,789 pools according date of collection, location, and species, and analyzed by reverse transcription polymerase chain reaction (RT-PCR) to detect the presence of RNA belong to Flavivirus genus. WNV was detected in 27 mosquito pools, producing sequences similar to those of birds and human strains obtained in 2008 outbreak, pointed out the probable virus overwintering. Isolation of WNV was achieved from one of these pools. Moreover 56 pools of mosquitoes tested positive for Usutu virus (USUV). Most PCR positive pools consisted of Culex pipiens, which also was the most analyzed mosquito species (81.4% of specimens); interestingly, USUV RNA was also found in two Aedes albopictus mosquito pools. Simultaneous circulation of WNV and USUV in the survey area was highlighted by occurrence of 8 mosquito WNV- and USUV-positive pools and by the overlaying of the viruses “hot spots”, obtained by kernel density estimation (KDE) analysis. Land use of sampled stations pointed out a higher proportion of WNV-positive Cx. pipiens pool in rural environments respect the provenience of total sampled pool, while the USUV-positive pools were uniformly captured in the different environments. Conclusions/Significance Obtained data highlighting the possible role of Cx. pipiens mosquito as the main vector for WNV and USUV in Northern Italy, and the possible involvement of Ae. albopictus mosquito in USUV cycle. The described mosquito-based surveillance could constitute the foundation for a public health alert system targeting mosquito borne arboviruses. PMID:21179462

  17. Mosquitos and You! Mosquito Control and Prevention

    E-print Network

    Larva Egg Raft 4 #12; Mosquito Search 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1 M A L D P E O D R 17 HIDDEN WORDS MOSQUITO LARVA VIRUS PUPA WESTNILE EGGRAFT MALARIA DRAGONFLY HABITAT AFRICA 5 #12 Mosquitos and You! Mosquito Control and Prevention Kindergarten, First, and Second

  18. Finding the Right Plugin: Mosquitoes Have the Answer Tracey Chapman*

    E-print Network

    Nachman, Michael

    on the identification of seminal fluid proteins in the mosquito vectors of dengue/yellow fever and of malaria [15 injection in the yellow fever vector Aedes aegypti is also reported to affect flight (e.g., [23]), responses

  19. Insect Repellents: Modulators of mosquito odorant receptor activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes vector numerous pathogens that cause diseases including malaria, yellow fever, dengue fever and chikungunya. DEET, IR3535, Picaridin and 2-undecanone are insect repellents that are used to prevent interactions between humans and a broad array of disease vectors including mosquitoes. While...

  20. Vector competence of eastern and western forms of Psorophora columbiae (Diptera: Culicidae) mosquitoes for enzootic and epizootic Venezuelan equine encephalitis virus.

    PubMed

    Moncayo, Abelardo C; Lanzaro, Gregory; Kang, Wenli; Orozco, Arnoldo; Ulloa, Armando; Arredondo-Jiménez, Juan; Weaver, Scott C

    2008-03-01

    Venezuelan equine encephalitis virus (VEEV) continues to circulate enzootically in Mexico with the potential to re-emerge and cause disease in equines and humans in North America. We infected two geographically distinct mosquito populations of eastern Psorophora columbiae form columbiae (Chiapas, Mexico and Texas, United States) and one mosquito population of western Psorophora columbiae form toltecum (California, United States) with epizootic and enzootic IE VEEV and epizootic IAB VEEV. We detected no differences between epizootic and enzootic IE viruses in their ability to infect any of the mosquito populations analyzed, which suggested that neither species selects for epizootic IE viruses. Psorophora columbiae f. columbiae (Texas) were significantly less susceptible to infection by epizootic IE than Ps. columbiae f. columbiae (Mexico). Psorophora columbiae f. toltecum populations were more susceptible than Ps. columbiae f. columbiae populations to epizootic IE and IAB viruses. PMID:18337337

  1. Using Wolbachia-based release for suppression of Aedes mosquitoes: insights from genetic data and population simulations.

    PubMed

    Rasi?, Gordana; Endersby, Nancy M; Williams, Craig; Hoffmann, Ary A

    2014-07-01

    A novel strategy for suppressing disease transmission by Aedes aegypti, the main vector of dengue, uses releases of mosquitoes infected with the bacterium Wolbachia pipientis. Wolbachia are currently released to interfere with viral transmission, but there is also potential to use strains in mosquito suppression and elimination programs via the deleterious effects of the bacterium on the host. Mosquito suppression depends on target areas being relatively isolated to prevent reinvasion and on local climatic conditions. Here we explored the opportunity for suppression of A. aegypti in central Queensland, Australia, by using microsatellite data and simulations based on CIMSiM models of local weather conditions and breeding container data. Our results indicate that Wolbachia-induced extinctions in central Queensland are possible, although they may eventually be compromised by ongoing mosquito migration between towns until these sources are also suppressed. The results highlight a novel use of deleterious Wolbachia infections to achieve ecological as well as disease-related endpoints. PMID:25154109

  2. Evaluation of attractive toxic sugar bait (ATSB)—barrier for control of vector and nuisance mosquitoes and its effect on non-target organisms in sub-tropical environments in Florida

    PubMed Central

    Qualls, Whitney A.; Müller, Günter C.; Revay, Edita E.; Allan, Sandra A.; Arheart, Kristopher L.; Beier, John C.; Smith, Michal L.; Scott, Jodi M.; Kravchenko, Vasiliy D.; Hausmann, Axel; Yefremova, Zoya A.; Xue, Rui-De

    2014-01-01

    The efficacy of attractive toxic sugar baits (ATSB) with the active ingredient eugenol, an Environmental Protection Agency exempt compound, was evaluated against vector and nuisance mosquitoes in both laboratory and field studies. In the laboratory, eugenol combined in attractive sugar bait (ASB) solution provided high levels of mortality for Aedes aegypti, Culex quinquefasciatus, and Anopheles quadrimaculatus. Field studies demonstrated significant control: > 70% reduction for Aedes atlanticus, Ae. infirmatus, and Culex nigripalpus and > 50% reduction for An. crucians, Uranotaenia sapphirina, Culiseta melanura, and Cx. erraticus three weeks post ATSB application. Furthermore, non-target feeding of six insect orders, Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, and Orthoptera, was evaluated in the field after application of a dyed-ASB to flowering and non-flowering vegetation. ASB feeding (staining) was determined by dissecting the guts and searching for food dye with a dissecting microscope. The potential impact of ATSB on non-targets, applied on green non-flowering vegetation was low for all non-target groups (0.9%). However, application of the ASB to flowering vegetation resulted in significant staining of the non-target insect orders. This highlights the need for application guidelines to reduce non-target effects. No mortality was observed in laboratory studies with predatory non-targets, spiders, praying mantis, or ground beetles, after feeding for three days on mosquitoes engorged on ATSB. Overall, our laboratory and field studies support the use of eugenol as an active ingredient for controlling important vector and nuisance mosquitoes when used as an ATSB toxin. This is the first study demonstrating effective control of anophelines in non-arid environments which suggest that even in highly competitive sugar rich environments this method could be used for control of malaria in Latin American countries. PMID:24361724

  3. Mosquito species abundance and diversity in Malindi, Kenya and their potential implication in pathogen transmission.

    PubMed

    Mwangangi, Joseph M; Midega, Janet; Kahindi, Samuel; Njoroge, Laban; Nzovu, Joseph; Githure, John; Mbogo, Charles M; Beier, John C

    2012-01-01

    Mosquitoes (Diptera: Culicidae) are important vectors of human disease-causing pathogens. Mosquitoes are found both in rural and urban areas. Deteriorating infrastructure, poor access to health, water and sanitation services, increasing population density, and widespread poverty contribute to conditions that modify the environment, which directly influences the risk of disease within the urban and peri-urban ecosystem. The objective of this study was to evaluate the mosquito vector abundance and diversity in urban, peri-urban, and rural strata in Malindi along the Kenya coast. The study was conducted in the coastal district of Malindi between January and December 2005. Three strata were selected which were described as urban, peri-urban, and rural. Sampling was done during the wet and dry seasons. Sampling in the wet season was done in the months of April and June to cover the long rainy season and in November and December to cover the short rainy season, while the dry season was between January and March and September and October. Adult mosquito collection was done using Pyrethrum Spray Collection (PSC) and Centers for Disease Control and Prevention (CDC) light traps inside houses and specimens were identified morphologically. In the three strata (urban, peri-urban, and rural), 78.5% of the total mosquito (n?=?7,775) were collected using PSC while 18.1% (n?=?1,795) were collected using the CDC light traps. Using oviposition traps, mosquito eggs were collected and reared in the insectary which yielded 329 adults of which 83.8% (n?=?276) were Aedes aegypti and 16.2% (n?=?53) were Culex quinquefasciatus. The mosquito distribution in the three sites varied significantly in each collection site. Anopheles gambiae, Anopheles funestus and Anopheles coustani were predominant in the rural stratum while C. quinquefasciatus was mostly found in urban and peri-urban strata. However, using PSC and CDC light trap collection techniques, A. aegypti was only found in urban strata. In the three strata, mosquitoes were mainly found in high numbers during the wet season. Further, A. gambiae, C. quinquefasciatus, and A. aegypti mosquitoes were found occurring together inside the houses. This in turn exposes the inhabitants to an array of mosquito-borne diseases including malaria, bancroftian filariasis, and arboviruses (dengue fever, Yellow fever, Rift Valley fever, Chikungunya fever, and West Nile Virus). In conclusion, our findings provide useful information for the design of integrated mosquito and disease control programs in East African environments. PMID:21626425

  4. A comparison study of gravid and under house CO2 mosquito traps in Harris County, Texas 

    E-print Network

    White, Stephanie Lyn

    2008-10-10

    Harris County Mosquito Control Division (HCMCD) is responsible for surveillance of mosquito species that are vectors of St. Louis Encephalitis (SLE) virus and West Nile Virus (WNV) within Harris County, Texas, including the Houston metroplex...

  5. North American wetlands and mosquito control.

    PubMed

    Rey, Jorge R; Walton, William E; Wolfe, Roger J; Connelly, C Roxanne; O'Connell, Sheila M; Berg, Joe; Sakolsky-Hoopes, Gabrielle E; Laderman, Aimlee D

    2012-12-01

    Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

  6. The main sceneries of Chagas disease transmission. The vectors, blood and oral transmissions - A comprehensive review

    PubMed Central

    Coura, José Rodrigues

    2015-01-01

    This review deals with transmission of Trypanosoma cruzi by the most important domestic vectors, blood transfusion and oral intake. Among the vectors, Triatoma infestans, Panstrongylus megistus, Rhodnius prolixus, Triatoma dimidiata, Triatoma brasiliensis, Triatoma pseudomaculata, Triatoma sordida, Triatoma maculata, Panstrongylus geniculatus, Rhodnius ecuadoriensis and Rhodnius pallescens can be highlighted. Transmission of Chagas infection, which has been brought under control in some countries in South and Central America, remains a great challenge, particularly considering that many endemic countries do not have control over blood donors. Even more concerning is the case of non-endemic countries that receive thousands of migrants from endemic areas that carry Chagas disease, such as the United States of America, in North America, Spain, in Europe, Japan, in Asia, and Australia, in Oceania. In the Brazilian Amazon Region, since Shaw et al. (1969) described the first acute cases of the disease caused by oral transmission, hundreds of acute cases of the disease due to oral transmission have been described in that region, which is today considered to be endemic for oral transmission. Several other outbreaks of acute Chagas disease by oral transmission have been described in different states of Brazil and in other South American countries. PMID:25466622

  7. Mosquito diapause.

    PubMed

    Denlinger, David L; Armbruster, Peter A

    2014-01-01

    Diapause, a dominant feature in the life history of many mosquito species, offers a mechanism for bridging unfavorable seasons in both temperate and tropical environments and serves to synchronize development within populations, thus directly affecting disease transmission cycles. The trait appears to have evolved independently numerous times within the Culicidae, as exemplified by the diverse developmental stages of diapause in closely related species. Its impact is pervasive, not only influencing the arrested stage, but also frequently altering physiological processes both before and after diapause. How the diapause response can be molded evolutionarily is critical for understanding potential range expansions of native and newly introduced species. The study of hormonal regulation of mosquito diapause has focused primarily on adult diapause, with little current information available on larval diapause or the intriguing maternal effects that regulate egg diapause. Recent quantitative trait locus, transcriptome, and RNA interference studies hold promise for interpreting the complex suite of genes that subserve the diapause phenotype. PMID:24160427

  8. Spatial model for transmission of mosquito-borne diseases

    NASA Astrophysics Data System (ADS)

    Kon, Cynthia Mui Lian; Labadin, Jane

    2015-05-01

    In this paper, a generic model which takes into account spatial heterogeneity for the dynamics of mosquito-borne diseases is proposed. The dissemination of the disease is described by a system of reaction-diffusion partial differential equations. Host human and vector mosquito populations are divided into susceptible and infectious classes. Diffusion is considered to occur in all classes of both populations. Susceptible humans are infected when bitten by infectious mosquitoes. Susceptible mosquitoes bite infectious humans and become infected. The biting rate of mosquitoes is considered to be density dependent on the total human population in different locations. The system is solved numerically and results are shown.

  9. Human to Mosquito Transmission of Dengue Viruses

    PubMed Central

    Carrington, Lauren B.; Simmons, Cameron P.

    2014-01-01

    The successful transmission of dengue virus from a human host to a mosquito vector requires a complex set of factors to align. It is becoming increasingly important to improve our understanding of the parameters that shape the human to mosquito component of the transmission cycle so that vaccines and therapeutic antivirals can be fully evaluated and epidemiological models refined. Here we describe these factors, and discuss the biological and environmental impacts and demographic changes that are influencing these dynamics. Specifically, we examine features of the human infection required for the mosquito to acquire the virus via natural blood feeding, as well as the biological and environmental factors that influence a mosquito’s susceptibility to infection, up to the point that they are capable of transmitting the virus to a new host. PMID:24987394

  10. Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in northern Sudan: influence of environmental factors and implications for vector control

    PubMed Central

    Ageep, Tellal B; Cox, Jonathan; Hassan, M'oawia M; Knols, Bart GJ; Benedict, Mark Q; Malcolm, Colin A; Babiker, Ahmed; El Sayed, Badria B

    2009-01-01

    Background Malaria is an important public health problem in northern Sudan, but little is known about the dynamics of its transmission. Given the characteristic low densities of Anopheles arabiensis and the difficult terrain in this area, future vector control strategies are likely to be based on area-wide integrated pest management (AW-IPM) that may include the sterile insect technique (SIT). To support the planning and implementation of future AW-IPM activities, larval surveys were carried out to provide key data on spatial and seasonal dynamics of local vector populations. Methods Monthly cross-sectional larval surveys were carried out between March 2005 and May 2007 in two localities (Dongola and Merowe) adjacent to the river Nile. A stratified random sampling strategy based on the use of Remote Sensing (RS), Geographical Information Systems (GIS) and the Global Positioning System (GPS) was used to select survey locations. Breeding sites were mapped using GPS and data on larval density and breeding site characteristics were recorded using handheld computers. Bivariate and multivariate logistic regression models were used to identify breeding site characteristics associated with increased risk of presence of larvae. Seasonal patterns in the proportion of breeding sites positive for larvae were compared visually to contemporaneous data on climate and river height. Results Of a total of 3,349 aquatic habitats sampled, 321 (9.6%) contained An. arabiensis larvae. The frequency with which larvae were found varied markedly by habitat type. Although most positive sites were associated with temporary standing water around the margins of the main Nile channel, larvae were also found at brickworks and in areas of leaking pipes and canals – often far from the river. Close to the Nile channel, a distinct seasonal pattern in larval populations was evident and appeared to be linked to the rise and fall of the river level. These patterns were not evident in vector populations breeding in artificial water sources away from the river. Conclusion The GIS-based survey strategy developed in this study provides key data on the population dynamics of An. arabiensis in Northern State. Quantitative estimates of the contributions of various habitat types and their proximity to settlements provide a basis for planning a strategy for reducing malaria risk by elimination of the vector population. PMID:19500425

  11. Hydrology and Mosquito Population Dynamics around a Hydropower Reservoir in Africa

    NASA Astrophysics Data System (ADS)

    Endo, N.; Eltahir, E. A.

    2013-12-01

    Malaria is associated with dams because their reservoirs provide mosquitoes, the vector of malaria, with permanent breeding sites. The risk of contracting malaria is likely to be enhanced following the increasing trend of hydropower dam construction to satisfy the expanding energy needs in developing countries. A close examination of its adverse health impacts is critical in the design, construction, and operation phases. We will present results of extensive field studies in 2012 and 2013 around the Koka Reservoir, Ethiopia. The results uncover the importance of reservoir management especially after the rainy seasons. Furthermore, we show the capability of a newly modified hydrology, entomology and malaria transmission simulator, HYDREMATS (Bomblies et al, 2008), and its potential as a tool for evaluating environmental management strategies to control malaria. HYDREMATS was developed to represent how the hydrology in nearby villages is impacted by the reservoir system, and the role of different types of vector ecologies associated with different Anopheles mosquito species. The hydrology component of HYDREMATS simulates three different mosquito breeding habitats: rain-fed pools, groundwater pools, and shoreline water. The entomology component simulates the life cycles of An. funestus and An. arabiensis, the two main vectors around the reservoir. The model was calibrated over the 2012-2013 period. The impact of reservoir water level management on the mosquito population is explored based on numerical model simulations and field experiments.

  12. Evolution of mosquito preference for humans linked to an odorant receptor.

    PubMed

    McBride, Carolyn S; Baier, Felix; Omondi, Aman B; Spitzer, Sarabeth A; Lutomiah, Joel; Sang, Rosemary; Ignell, Rickard; Vosshall, Leslie B

    2014-11-13

    Female mosquitoes are major vectors of human disease and the most dangerous are those that preferentially bite humans. A 'domestic' form of the mosquito Aedes aegypti has evolved to specialize in biting humans and is the main worldwide vector of dengue, yellow fever, and chikungunya viruses. The domestic form coexists with an ancestral, 'forest' form that prefers to bite non-human animals and is found along the coast of Kenya. We collected the two forms, established laboratory colonies, and document striking divergence in preference for human versus non-human animal odour. We further show that the evolution of preference for human odour in domestic mosquitoes is tightly linked to increases in the expression and ligand-sensitivity of the odorant receptor AaegOr4, which we found recognizes a compound present at high levels in human odour. Our results provide a rare example of a gene contributing to behavioural evolution and provide insight into how disease-vectoring mosquitoes came to specialize on humans. PMID:25391959

  13. Mosquito surveillance for West Nile virus in southeastern Wisconsin--2002.

    PubMed

    Meece, Jennifer K; Henkel, James S; Glaser, Linda; Reed, Kurt D

    2003-01-01

    In 2001, West Nile virus (WNV) was identified among dead American crows and bluejays in five counties in southeastern Wisconsin. In response to the introduction of WNV, a pilot mosquito surveillance program was initiated in these five southeastern Wisconsin counties during the summer of 2002. Forty sites were selected for surveillance one night each week during a 17-week period. Mosquitoes were collected in carbon dioxide-baited light traps and gravid traps. During the study period 31,419 mosquitoes were collected, identified to species level and pooled into groups of up to 50 mosquitoes of like species from each collection site. Twenty-five different mosquito species were identified with the common pest mosquitoes, Aedes vexans and Ochlerotatus trivittatus, being the most abundant. Seventeen of the 25 mosquito species found in southeastern Wisconsin have previously been shown to be carriers of WNV in other parts of the U.S. Only 2/1,592 (0.126%) mosquito pools from Wisconsin were positive for WNV by cell culture and reverse transcription polymerase chain reaction (RT-PCR). Active mosquito surveillance is useful for identifying potential mosquito vectors of arboviruses in defined geographic areas, and to monitor population densities of those vectors. This information coupled with infection rate data can help guide public health policies related to vector control, and may help reduce the impact on human, veterinary and bird mortality. PMID:15931283

  14. Vectors

    NSDL National Science Digital Library

    Stern, David P. (David Peter), 1931-

    This web page, authored and curated by David P. Stern, introduces vectors as an extension of numbers having both magnitude and direction. The initial motivation is to describe velocity but the material includes a general discussion of vector algebra and an application to forces for the inclined plane. The page contains links to a related lesson plan and further opportunities to explore vectors. This is part of the extensive web site "From Stargazers to Starships", that uses space exploration and space science to introduce topics in physics and astronomy. Translations in Spanish and French are available.

  15. An Anopheles transgenic sexing strain for vector control

    Microsoft Academic Search

    Flaminia Catteruccia; Jason P Benton; Andrea Crisanti

    2005-01-01

    Genetic manipulation of mosquito species that serve as vectors for human malaria is a prerequisite to the implementation of gene transfer technologies for the control of vector-borne diseases. Here we report on the development of transgenic sexing lines for the mosquito Anopheles stephensi, the principal vector of human malaria in Asia. Male mosquitoes, expressing enhanced green fluorescent protein (EGFP) under

  16. Approaches to passive mosquito surveillance in the EU.

    PubMed

    Kampen, Helge; Medlock, Jolyon M; Vaux, Alexander G C; Koenraadt, Constantianus J M; van Vliet, Arnold J H; Bartumeus, Frederic; Oltra, Aitana; Sousa, Carla A; Chouin, Sébastien; Werner, Doreen

    2015-01-01

    The recent emergence in Europe of invasive mosquitoes and mosquito-borne disease associated with both invasive and native mosquito species has prompted intensified mosquito vector research in most European countries. Central to the efforts are mosquito monitoring and surveillance activities in order to assess the current species occurrence, distribution and, when possible, abundance, in order to permit the early detection of invasive species and the spread of competent vectors. As active mosquito collection, e.g. by trapping adults, dipping preimaginal developmental stages or ovitrapping, is usually cost-, time- and labour-intensive and can cover only small parts of a country, passive data collection approaches are gradually being integrated into monitoring programmes. Thus, scientists in several EU member states have recently initiated programmes for mosquito data collection and analysis that make use of sources other than targeted mosquito collection. While some of them extract mosquito distribution data from zoological databases established in other contexts, community-based approaches built upon the recognition, reporting, collection and submission of mosquito specimens by citizens are becoming more and more popular and increasingly support scientific research. Based on such reports and submissions, new populations, extended or new distribution areas and temporal activity patterns of invasive and native mosquito species were found. In all cases, extensive media work and communication with the participating individuals or groups was fundamental for success. The presented projects demonstrate that passive approaches are powerful tools to survey the mosquito fauna in order to supplement active mosquito surveillance strategies and render them more focused. Their ability to continuously produce biological data permits the early recognition of changes in the mosquito fauna that may have an impact on biting nuisance and the risk of pathogen transmission associated with mosquitoes. International coordination to explore synergies and increase efficiency of passive surveillance programmes across borders needs to be established. PMID:25567671

  17. Malaria Parasites Produce Volatile Mosquito Attractants

    PubMed Central

    Kelly, Megan; Su, Chih-Ying; Schaber, Chad; Crowley, Jan R.; Hsu, Fong-Fu; Carlson, John R.

    2015-01-01

    ABSTRACT The malaria parasite Plasmodium falciparum contains a nonphotosynthetic plastid organelle that possesses plant-like metabolic pathways. Plants use the plastidial isoprenoid biosynthesis pathway to produce volatile odorants, known as terpenes. In this work, we describe the volatile chemical profile of cultured malaria parasites. Among the identified compounds are several plant-like terpenes and terpene derivatives, including known mosquito attractants. We establish the molecular identity of the odorant receptors of the malaria mosquito vector Anopheles gambiae, which responds to these compounds. The malaria parasite produces volatile signals that are recognized by mosquitoes and may thereby mediate host attraction and facilitate transmission. PMID:25805727

  18. Bionomics of the common mosquitoes of Dacca

    Microsoft Academic Search

    Mahmud-Ul Ameen; Muhammad Moizuddin

    1973-01-01

    Mosquito-borne diseases, other than malaria, are becoming important public health problems in Bangladesh. Knowledge of the bionomics of the vector species is a pre-requisite for planning effective control measures against insect-borne diseases. With the above end in view, the bionomics of the common mosquitoes of Dacca city have been discussed under four headings, viz., seasonal prevalence, host preference, activity periods,

  19. Physico-chemical and biological characterization of anopheline mosquito larval habitats (Diptera: Culicidae): implications for malaria control

    PubMed Central

    2013-01-01

    Background A fundamental understanding of the spatial distribution and ecology of mosquito larvae is essential for effective vector control intervention strategies. In this study, data-driven decision tree models, generalized linear models and ordination analysis were used to identify the most important biotic and abiotic factors that affect the occurrence and abundance of mosquito larvae in Southwest Ethiopia. Methods In total, 220 samples were taken at 180 sampling locations during the years 2010 and 2012. Sampling sites were characterized based on physical, chemical and biological attributes. The predictive performance of decision tree models was evaluated based on correctly classified instances (CCI), Cohen’s kappa statistic (?) and the determination coefficient (R2). A conditional analysis was performed on the regression tree models to test the relation between key environmental and biological parameters and the abundance of mosquito larvae. Results The decision tree model developed for anopheline larvae showed a good model performance (CCI?=?84?±?2%, and ??=?0.66?±?0.04), indicating that the genus has clear habitat requirements. Anopheline mosquito larvae showed a widespread distribution and especially occurred in small human-made aquatic habitats. Water temperature, canopy cover, emergent vegetation cover, and presence of predators and competitors were found to be the main variables determining the abundance and distribution of anopheline larvae. In contrast, anopheline mosquito larvae were found to be less prominently present in permanent larval habitats. This could be attributed to the high abundance and diversity of natural predators and competitors suppressing the mosquito population densities. Conclusions The findings of this study suggest that targeting smaller human-made aquatic habitats could result in effective larval control of anopheline mosquitoes in the study area. Controlling the occurrence of mosquito larvae via drainage of permanent wetlands may not be a good management strategy as it negatively affects the occurrence and abundance of mosquito predators and competitors and promotes an increase in anopheline population densities. PMID:24499518

  20. Prospects for the mosquito baculovirus CuniNPV as a tool for mosquito control.

    PubMed

    Becnel, James J

    2006-09-01

    CuniNPV is a pathogen of Culex mosquitoes, vectors of West Nile virus and other forms of encephalitis. Successful development of CuniNPV requires an efficient production system and formulated product that incorporates magnesium, an essential component for transmission. It may be possible to develop mosquito baculoviruses as a new type of biopesticide by microencapsulating the virus and magnesium into formulations that would be effective regardless of the water quality. In addition, this new insight on transmission may facilitate the discovery and development of additional baculoviruses for the control of other important mosquito vectors. Biological mining of the CuniNPV genome and investigations to understand virus-mosquito interactions at the molecular level offer exciting possibilities for the development of novel mosquito control strategies and tools. Understanding the molecular mechanisms of infection will provide the opportunity to devise new control strategies, for example, compromising the defensive systems of the mosquito (proteases for the peritrophic matrix) or exploiting receptors used by the virus to specifically deliver toxins to mosquito larvae via the midgut. As additional baculovirus genomes become available, comparative genomics could lead to a more informed understanding of how the virus exploits its host as well as the factors responsible for the genus-specific host range of most known mosquito baculoviruses. PMID:17067056

  1. Differential Expression of Salivary Proteins between Susceptible and Insecticide-Resistant Mosquitoes of Culex quinquefasciatus

    Microsoft Academic Search

    Innocent Djegbe; Sylvie Cornelie; Marie Rossignol; Edith Demettre; Martial Seveno; Franck Remoue; Vincent Corbel; Alan Christoffels

    2011-01-01

    BackgroundThe Culex quinquefasciatus mosquito, a major pest and vector of filariasis and arboviruses in the tropics, has developed multiple resistance mechanisms to the main insecticide classes currently available in public health. Among them, the insensitive acetylcholinesterase (ace-1R allele) is widespread worldwide and confers cross-resistance to organophosphates and carbamates. Fortunately, in an insecticide-free environment, this mutation is associated with a severe

  2. Diversity and function of bacterial microbiota in the mosquito holobiont

    PubMed Central

    2013-01-01

    Mosquitoes (Diptera: Culicidae) have been shown to host diverse bacterial communities that vary depending on the sex of the mosquito, the developmental stage, and ecological factors. Some studies have suggested a potential role of microbiota in the nutritional, developmental and reproductive biology of mosquitoes. Here, we present a review of the diversity and functions of mosquito-associated bacteria across multiple variation factors, emphasizing recent findings. Mosquito microbiota is considered in the context of possible extended phenotypes conferred on the insect hosts that allow niche diversification and rapid adaptive evolution in other insects. These kinds of observations have prompted the recent development of new mosquito control methods based on the use of symbiotically-modified mosquitoes to interfere with pathogen transmission or reduce the host life span and reproduction. New opportunities for exploiting bacterial function for vector control are highlighted. PMID:23688194

  3. Vectors and transmission dynamics for Setaria tundra (Filarioidea; Onchocercidae), a parasite of reindeer in Finland

    PubMed Central

    Laaksonen, Sauli; Solismaa, Milla; Kortet, Raine; Kuusela, Jussi; Oksanen, Antti

    2009-01-01

    Background Recent studies have revealed expansion by an array of Filarioid nematodes' into the northern boreal region of Finland. The vector-borne nematode, Setaria tundra, caused a serious disease outbreak in the Finnish reindeer population in 2003–05. The main aim of this study was to understand the outbreak dynamics and the rapid expansion of S. tundra in the sub arctic. We describe the vectors of S. tundra, and its development in vectors, for the first time. Finally we discuss the results in the context of the host-parasite ecology of S. tundra in Finland Results Development of S. tundra to the infective stage occurs in mosquitoes, (genera Aedes and Anopheles). We consider Aedes spp. the most important vectors. The prevalence of S. tundra naturally infected mosquitoes from Finland varied from 0.5 to 2.5%. The rate of development in mosquitoes was temperature-dependent. Infective larvae were present approximately 14 days after a blood meal in mosquitoes maintained at room temperature (mean 21 C), but did not develop in mosquitoes maintained outside for 22 days at a mean temperature of 14.1 C. The third-stage (infective) larvae were elongated (mean length 1411 ?m (SD 207), and width 28 ?m (SD 2)). The anterior end was blunt, and bore two liplike structures, the posterior end slight tapering with a prominent terminal papilla. Infective larvae were distributed anteriorly in the insect's body, the highest abundance being 70 larvae in one mosquito. A questionnaire survey revealed that the peak activity of Culicidae in the reindeer herding areas of Finland was from the middle of June to the end of July and that warm summer weather was associated with reindeer flocking behaviour on mosquito-rich wetlands. Conclusion In the present work, S. tundra vectors and larval development were identified and described for the first time. Aedes spp. mosquitoes likely serve as the most important and competent vectors for S. tundra in Finland. Warm summers apparently promote transmission and genesis of disease outbreaks by favouring the development of S. tundra in its mosquito vectors, by improving the development and longevity of mosquitoes, and finally by forcing the reindeer to flock on mosquito rich wetlands. Thus we predict that global climate change has the potential to promote the further emergence of Filarioid nematodes and the disease caused by them in subarctic regions. PMID:19126197

  4. Seasonal and Temporal Variations in the Population and Biting Habit of Mosquitoes on the Atlantic Coast of Lagos, Nigeria

    Microsoft Academic Search

    B. M. Afolabi; C. N. Amajoh; T. A. Adewole; L. A. Salako

    2006-01-01

    Objectives: To determine the hourly density of vector mosquitoes in coastal Nigeria, compare seasonal human-biting and sporozoite rates in the vector density, locate breeding sites of mosquitoes, and determine larval population at breeding sites. Materials and Methods: Indoor and outdoor mosquitoes of a coastal Nigerian community were caught during early and late wet seasons and in the harmattan period, a

  5. 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

    PubMed Central

    2012-01-01

    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 brackish water-derived Ae. aegypti larvae at high salinities. Conclusion A variety of mosquito vectors of human diseases undergo pre-imaginal development in brackish or saline waters in coastal areas of the Jaffna district in northern Sri Lanka. Salinity has a small but significant negative impact on the toxicity of B. thuringiensis toxin to Ae. aegypti larvae at salinity levels where Ae. aegypti larvae are found in the environment. This has implications for the use of B. thuringiensis toxin as a larvicide in brackish waters. PMID:23174003

  6. Analyses of ?-amylase and ?-glucosidase in the malaria vector mosquito, Anopheles gambiae, as receptors of Cry11Ba toxin of Bacillus thuringiensis subsp. jegathesan.

    PubMed

    Zhang, Qi; Hua, Gang; Bayyareddy, Krishnareddy; Adang, Michael J

    2013-10-01

    Bacillus thuringiensis subsp. jegathesan produces Cry11Ba crystal protein with high toxicity to mosquito larvae. The Cry11Ba toxicity is dependent on its receptors on mosquito larval midgut epithelial cells. Previously, a cadherin-like protein (AgCad2), aminopeptidase (AgAPN2) and alkaline phosphatase (AgALP1) were reported to be involved in regulation of Cry11Ba toxicity on Anopheles gambiae larvae. Here, the cDNAs encoding ?-amylase (AgAmy1) and ?-glucosidase (Agm3) were cloned from A. gambiae larva midgut. Both are glycophosphatidylinositol (GPI) anchored proteins on brush border membranes (BBMV). Immunohistochemistry revealed their localization on different regions of the larval midgut. AgAmy1 and Agm3 bound Cry11Ba with high affinity, 37.6 nM and 21.1 nM respectively. Cry11Ba toxicity against A. gambiae larvae was neutralized by both AgAmy1 and Agm3. The results provide evidence that both AgAmy1 and Agm3 function as receptors of Cry11Ba in A. gambiae. PMID:23872242

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

    PubMed

    Arbaoui, A A; Chua, T H

    2014-03-01

    Since a safe and effective mass vaccination program against dengue fever is not presently available, a good way to prevent and control dengue outbreaks depends mainly on controlling the mosquito vectors. Aedes aegypti mosquito populations can be monitored and reduced by using ovitraps baited with organic infusions. A series of laboratory experiments were conducted which demonstrated that the bacteria in bamboo leaf infusion produce volatile attractants and contact chemical stimulants attractive to the female mosquitoes. The results showed that the female mosquitoes laid most of their eggs (59.9 ± 8.1 vs 2.9 ± 2.8 eggs, P<0.001) in bamboo leaf infusions when compared to distilled water. When the fresh infusion was filtered with a 0.45 ?m filter membrane, the female mosquitoes laid significantly more eggs (64.1 ± 6.6 vs 4.9 ± 2.6 eggs, P<0.001) in unfiltered infusion. However when a 0.8 ?m filter membrane was used, the female laid significantly more eggs (62.0 ± 4.3 vs 10.1 ± 7.8 eggs, P<0.001) in filtrate compared to a solution containing the residue. We also found that a mixture of bacteria isolated from bamboo leaf infusion serve as potent oviposition stimulants for gravid Aedes mosquitoes. Aedes aegypti laid significantly more eggs (63.3 ± 6.5 vs 3.1 ± 2.4 eggs, P<0.001) in bacteria suspension compared to sterile R2A medium. Our results suggest microbial activity has a role in the production of odorants that mediate the oviposition response of gravid mosquitoes. PMID:24862053

  8. Do capture data from mosquito traps represent reality?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Collectively, the effects of mechanical trap style, the method of trap placement in the field, mosquito activity phase, and other biological phenomena are manifest as sample bias that leads to vector detection failure(s) and/or erroneous predictions of mosquito activity. The goal of this research i...

  9. Natural skip oviposition of the mosquito Aedes aegypti indicated by codominant genetic markers

    E-print Network

    Severson, David

    larvae, oviposition behaviour, relatedness, RFLP, skip-oviposition, vector biology, yellow fever mosquitoNatural skip oviposition of the mosquito Aedes aegypti indicated by codominant genetic markers Y. M within and among oviposition sites used by the mosquito Aedes aegypti (L) (Diptera: Culicidae). Estimates

  10. Countering a Bioterrorist Introduction of Pathogen-Infected Mosquitoes through Mosquito Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A workshop titled “Counteracting Bioterrorist Introduction of Pathogen-Infected Vector Mosquitoes” was held in Gainesville, Florida on May 20-22, 2010 to discuss (1) disease and vector surveillance, (2) pre-bioterrorist attack preparations, (3) actions during an ongoing bioterrorist attack, and (4) ...

  11. Mechanistic modelling of the links between environment, mosquitoes and malaria transmission in the current and future climates of West Africa

    E-print Network

    Yamana, Teresa K. (Teresa Keiko)

    2015-01-01

    Malaria transmission in West Africa is closely tied to climate, as rain fed water pools provide breeding habitat for the anopheles mosquito vector, and temperature affects the mosquito's ability to spread disease. This ...

  12. Plant based products: use and development as repellents against mosquitoes: A review.

    PubMed

    Rehman, Junaid U; Ali, Abbas; Khan, Ikhlas A

    2014-06-01

    Global warming and deforestation have resulted in the relocation of many living creatures including insects during the recent years. This has affected the population balance of disease vectors including mosquitoes resulting in outbreaks. Traditionally, mankind has been using plants as means of protection from the mosquitoes which are considered to be environment friendly unlike the synthetic chemicals that cause major risk to human health and the ecosystem. Researchers explored mainly, essential oils and traditional plants using different testing methodologies to find out repellent molecules effective against mosquitoes which is the main focus of this review. Among the promising plant species, Eucalyptus spp., Ocimum spp. and Cymbopogon spp. are the most cited. Data of repellency produced from the bioassay systems is difficult to quantify because of different parameters, testing system and standards of material used against mosquitoes. Mainly, the human forearm based bioassays have been used with different sizes of treatment area in the laboratory and the results have not been tested in the field conditions for residual activity. In addition, effectiveness of essential oils and their protection time can be increased by using vanillin as synergist and formulation techniques like microencapsulation and nanoemulsion. There is a need to develop an alternate in vitro bioassay system that can address the problems of uniformity of the results. PMID:24631763

  13. Stability and Wash Resistance of Local Made Mosquito Bednets and Detergents Treated with Pyrethroids against Susceptible Strain of Malaria Vector Anopheles stephensi

    PubMed Central

    Vatandoost, H; Ramin, E; Rassi, Y; Abai, MR

    2009-01-01

    Background We aimed to evaluate different fibres of bednets impregnated with various pyrethroids. The stability of insecticide on the bednet was measured using different methods of washings as well as local made detergents. Methods: The entire test was carried out according to the WHO-recommended methods. In addition, the impact of the numbers of washes on the stability of the insecticides was determined. Permethrin 10% (EC), deltamethrin 10% (SC), lambdacyhalothrin 2.5% (CS) and cyfluthrin 5% (EW) were used at the recommended dosages. Three different local detergents were used. Two kinds of washing methods (shaking, no shaking) were used and in each method four kinds of washings, i.e. no wash, one wash, two washes and three washes was done. The main malaria vectors, Anopheles stephensi, which is susceptible to all insecticides (BEECH strain), was tested with impregnated bednets in 3 minutes exposure time and the mortality was measured after 24 hours recovery period. Knock-down was measured as well using appropriate statistical methods. Results: Lambdacyhalothrin has saved its insecticidal impact after being washed, whereas, deltamethrin has lost its activity faster than other insecticides. Tow other insecticides had moderate effect. Golnar soap detergent has least effect on the durability of insecticides, but the Shoma had the most. Whit increasing the times of washing, insecticidal effects was decreased, but shaking had no influence on the decreasing of the quality of insecticidal impact. Conclusion: Results will be useful for local people who wish to use pyrethroid-impregnated bednets with their own local made detergent and bednets. PMID:22808368

  14. Old ingredients for a new recipe? Neem cake, a low-cost botanical by-product in the fight against mosquito-borne diseases.

    PubMed

    Benelli, Giovanni; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Madhiyazhagan, Pari; Conti, Barbara; Nicoletti, Marcello

    2015-02-01

    Mosquitoes (Diptera: Culicidae) represent an important threat to millions of people worldwide, since they act as vectors for important pathogens, such as malaria, yellow fever, dengue and West Nile. Control programmes mainly rely on chemical treatments against larvae, indoor residual spraying and insecticide-treated bed nets. In recent years, huge efforts have been carried out to propose new eco-friendly alternatives, with a special focus on the evaluation of plant-borne mosquitocidal compounds. Major examples are neem-based products (Azadirachta indica A. Juss, Meliaceae) that have been proven as really effective against a huge range of pests of medical and veterinary importance, including mosquitoes. Recent research highlighted that neem cake, a cheap by-product from neem oil extraction, is an important source of mosquitocidal metabolites. In this review, we examined (i) the latest achievements about neem cake metabolomics with special reference to nor-terpenoid and related content; (ii) the neem cake ovicidal, larvicidal and pupicidal toxicity against Aedes, Anopheles and Culex mosquito vectors; (iii) its non-target effects against vertebrates; and (iv) its oviposition deterrence effects on mosquito females. Overall, neem cake can be proposed as an eco-friendly and low-cost source of chemicals to build newer and safer control tools against mosquito vectors. PMID:25563612

  15. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis.

    PubMed

    Jeffries, Claire L; Walker, Thomas

    2015-06-01

    Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000-175,000, with 25%-30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a "dead-end" host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of "dengue-refractory" mosquito lines. The successful establishment of Wolbachia in wild Aedes aegypti populations has recently been demonstrated, and open releases in dengue-endemic countries are ongoing. This review outlines the current control methods for JEV in addition to highlighting the potential use of Wolbachia-based biocontrol strategies to impact transmission. JEV and dengue virus are both members of the Flavivirus genus, and the successful establishment of Drosophila Wolbachia strains in Cx. Tritaeniorhynchus, as the principal vector of JEV, is predicted to significantly impact JEV transmission. PMID:26086337

  16. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis

    PubMed Central

    Jeffries, Claire L.; Walker, Thomas

    2015-01-01

    Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000–175,000, with 25%–30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a “dead-end” host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of “dengue-refractory” mosquito lines. The successful establishment of Wolbachia in wild Aedes aegypti populations has recently been demonstrated, and open releases in dengue-endemic countries are ongoing. This review outlines the current control methods for JEV in addition to highlighting the potential use of Wolbachia-based biocontrol strategies to impact transmission. JEV and dengue virus are both members of the Flavivirus genus, and the successful establishment of Drosophila Wolbachia strains in Cx. Tritaeniorhynchus, as the principal vector of JEV, is predicted to significantly impact JEV transmission. PMID:26086337

  17. Comparative Genome Analysis of the Yellow Fever Mosquito Aedes aegypti

    E-print Network

    Severson, David

    Comparative Genome Analysis of the Yellow Fever Mosquito Aedes aegypti with Drosophila melanogaster aegypti, and Culex pipiens, the primary vectors for malaria, yellow fever and dengue, and lymphatic 103

  18. Virtual mosquito

    NSDL National Science Digital Library

    0000-00-00

    3D virtual image of a mosquito (Family Culicidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the Â?HelpÂ? page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

  19. A Modified Experimental Hut Design for Studying Responses of Disease-Transmitting Mosquitoes to Indoor Interventions: The Ifakara Experimental Huts

    PubMed Central

    Okumu, Fredros O.; Moore, Jason; Mbeyela, Edgar; Sherlock, Mark; Sangusangu, Robert; Ligamba, Godfrey; Russell, Tanya; Moore, Sarah J.

    2012-01-01

    Differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (ITNs) and indoor residual insecticide spraying (IRS). Specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes. However, many of these experimental hut designs have a number of limitations, for example: 1) inability to sample mosquitoes on all sides of huts, 2) increased likelihood of live mosquitoes flying out of the huts, leaving mainly dead ones, 3) difficulties of cleaning the huts when a new insecticide is to be tested, and 4) the generally small size of the experimental huts, which can misrepresent actual local house sizes or airflow dynamics in the local houses. Here, we describe a modified experimental hut design - The Ifakara Experimental Huts- and explain how these huts can be used to more realistically monitor behavioural and physiological responses of wild, free-flying disease-transmitting mosquitoes, including the African malaria vectors of the species complexes Anopheles gambiae and Anopheles funestus, to indoor vector control-technologies including ITNs and IRS. Important characteristics of the Ifakara experimental huts include: 1) interception traps fitted onto eave spaces and windows, 2) use of eave baffles (panels that direct mosquito movement) to control exit of live mosquitoes through the eave spaces, 3) use of replaceable wall panels and ceilings, which allow safe insecticide disposal and reuse of the huts to test different insecticides in successive periods, 4) the kit format of the huts allowing portability and 5) an improved suite of entomological procedures to maximise data quality. PMID:22347415

  20. Rickettsia Species in African Anopheles Mosquitoes

    PubMed Central

    Socolovschi, Cristina; Pages, Frédéric; Ndiath, Mamadou O.; Ratmanov, Pavel; Raoult, Didier

    2012-01-01

    Background There is higher rate of R. felis infection among febrile patients than in healthy people in Sub-Saharan Africa, predominantly in the rainy season. Mosquitoes possess a high vectorial capacity and, because of their abundance and aggressiveness, likely play a role in rickettsial epidemiology. Methodology/Principal Findings Quantitative and traditional PCR assays specific for Rickettsia genes detected rickettsial DNA in 13 of 848 (1.5%) Anopheles mosquitoes collected from Côte d’Ivoire, Gabon, and Senegal. R. felis was detected in one An. gambiae molecular form S mosquito collected from Kahin, Côte d’Ivoire (1/77, 1.3%). Additionally, a new Rickettsia genotype was detected in five An. gambiae molecular form S mosquitoes collected from Côte d’Ivoire (5/77, 6.5%) and one mosquito from Libreville, Gabon (1/88, 1.1%), as well as six An. melas (6/67, 9%) mosquitoes collected from Port Gentil, Gabon. A sequence analysis of the gltA, ompB, ompA and sca4 genes indicated that this new Rickettsia sp. is closely related to R. felis. No rickettsial DNA was detected from An. funestus, An. arabiensis, or An. gambiae molecular form M mosquitoes. Additionally, a BLAST analysis of the gltA sequence from the new Rickettsia sp. resulted in a 99.71% sequence similarity to a species (JQ674485) previously detected in a blood sample of a Senegalese patient with a fever from the Bandafassi village, Kedougou region. Conclusion R. felis was detected for the first time in An. gambiae molecular form S, which represents the major African malaria vector. The discovery of R. felis, as well as a new Rickettsia species, in mosquitoes raises new issues with respect to African rickettsial epidemiology that need to be investigated, such as bacterial isolation, the degree of the vectorial capacity of mosquitoes, the animal reservoirs, and human pathogenicity. PMID:23118963

  1. Mosquito, egg raft (image)

    MedlinePLUS

    Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in ... feed on micro-organisms before developing into flying mosquitoes. (Image courtesy of the Centers for Disease Control ...

  2. Pesticides and Mosquito Control

    NSDL National Science Digital Library

    This factsheet from the Environmental Protection Agency includes several summary documents on the problem of mosquito-borne diseases and the pesticides used to control mosquitoes. The resources cover issues from mosquito biology through the EPA's recent findings on the negative health impacts of Malathion.

  3. Mosquito population regulation and larval source management in heterogeneous environments.

    PubMed

    Smith, David L; Perkins, T Alex; Tusting, Lucy S; Scott, Thomas W; Lindsay, Steven W

    2013-01-01

    An important question for mosquito population dynamics, mosquito-borne pathogen transmission and vector control is how mosquito populations are regulated. Here we develop simple models with heterogeneity in egg laying patterns and in the responses of larval populations to crowding in aquatic habitats. We use the models to evaluate how such heterogeneity affects mosquito population regulation and the effects of larval source management (LSM). We revisit the notion of a carrying capacity and show how heterogeneity changes our understanding of density dependence and the outcome of LSM. Crowding in and productivity of aquatic habitats is highly uneven unless egg-laying distributions are fine-tuned to match the distribution of habitats' carrying capacities. LSM reduces mosquito population density linearly with coverage if adult mosquitoes avoid laying eggs in treated habitats, but quadratically if eggs are laid in treated habitats and the effort is therefore wasted (i.e., treating 50% of habitat reduces mosquito density by approximately 75%). Unsurprisingly, targeting (i.e. treating a subset of the most productive pools) gives much larger reductions for similar coverage, but with poor targeting, increasing coverage could increase adult mosquito population densities if eggs are laid in higher capacity habitats. Our analysis suggests that, in some contexts, LSM models that accounts for heterogeneity in production of adult mosquitoes provide theoretical support for pursuing mosquito-borne disease prevention through strategic and repeated application of modern larvicides. PMID:23951118

  4. Mosquito Population Regulation and Larval Source Management in Heterogeneous Environments

    PubMed Central

    Smith, David L.; Perkins, T. Alex; Tusting, Lucy S.; Scott, Thomas W.; Lindsay, Steven W.

    2013-01-01

    An important question for mosquito population dynamics, mosquito-borne pathogen transmission and vector control is how mosquito populations are regulated. Here we develop simple models with heterogeneity in egg laying patterns and in the responses of larval populations to crowding in aquatic habitats. We use the models to evaluate how such heterogeneity affects mosquito population regulation and the effects of larval source management (LSM). We revisit the notion of a carrying capacity and show how heterogeneity changes our understanding of density dependence and the outcome of LSM. Crowding in and productivity of aquatic habitats is highly uneven unless egg-laying distributions are fine-tuned to match the distribution of habitats’ carrying capacities. LSM reduces mosquito population density linearly with coverage if adult mosquitoes avoid laying eggs in treated habitats, but quadratically if eggs are laid in treated habitats and the effort is therefore wasted (i.e., treating 50% of habitat reduces mosquito density by approximately 75%). Unsurprisingly, targeting (i.e. treating a subset of the most productive pools) gives much larger reductions for similar coverage, but with poor targeting, increasing coverage could increase adult mosquito population densities if eggs are laid in higher capacity habitats. Our analysis suggests that, in some contexts, LSM models that accounts for heterogeneity in production of adult mosquitoes provide theoretical support for pursuing mosquito-borne disease prevention through strategic and repeated application of modern larvicides. PMID:23951118

  5. The function and three-dimensional structure of a thromboxane A2/cysteinyl leukotriene-binding protein from the saliva of a mosquito vector of the malaria parasite.

    PubMed

    Alvarenga, Patricia H; Francischetti, Ivo M B; Calvo, Eric; Sá-Nunes, Anderson; Ribeiro, José M C; Andersen, John F

    2010-01-01

    The highly expressed D7 protein family of mosquito saliva has previously been shown to act as an anti-inflammatory mediator by binding host biogenic amines and cysteinyl leukotrienes (CysLTs). In this study we demonstrate that AnSt-D7L1, a two-domain member of this group from Anopheles stephensi, retains the CysLT binding function seen in the homolog AeD7 from Aedes aegypti but has lost the ability to bind biogenic amines. Unlike any previously characterized members of the D7 family, AnSt-D7L1 has acquired the important function of binding thromboxane A(2) (TXA(2)) and its analogs with high affinity. When administered to tissue preparations, AnSt-D7L1 abrogated Leukotriene C(4) (LTC(4))-induced contraction of guinea pig ileum and contraction of rat aorta by the TXA(2) analog U46619. The protein also inhibited platelet aggregation induced by both collagen and U46619 when administered to stirred platelets. The crystal structure of AnSt-D7L1 contains two OBP-like domains and has a structure similar to AeD7. In AnSt-D7L1, the binding pocket of the C-terminal domain has been rearranged relative to AeD7, making the protein unable to bind biogenic amines. Structures of the ligand complexes show that CysLTs and TXA(2) analogs both bind in the same hydrophobic pocket of the N-terminal domain. The TXA(2) analog U46619 is stabilized by hydrogen bonding interactions of the ?-5 hydroxyl group with the phenolic hydroxyl group of Tyr 52. LTC(4) and occupies a very similar position to LTE(4) in the previously determined structure of its complex with AeD7. As yet, it is not known what, if any, new function has been acquired by the rearranged C-terminal domain. This article presents, to our knowledge, the first structural characterization of a protein from mosquito saliva that inhibits collagen mediated platelet activation. PMID:21152418

  6. Symbiotic control of mosquito borne disease.

    PubMed

    Ricci, Irene; Valzano, Matteo; Ulissi, Ulisse; Epis, Sara; Cappelli, Alessia; Favia, Guido

    2012-11-01

    It is well accepted that the symbiotic relationships insects have established with several microorganisms have had a key role in their evolutionary success. Bacterial symbiosis is also prevalent in insects that are efficient disease vectors, and numerous studies have sought to decrypt the basic mechanisms of the host-symbiont relationships and develop ways to control vector borne diseases. 'Symbiotic control', a new multifaceted approach that uses symbiotic microorganisms to control insect pests or reduce vector competence, seems particularly promising. Three such approaches currently at the cutting edge are: (1) the disruption of microbial symbionts required by insect pests; (2) the manipulation of symbionts that can express anti-pathogen molecules within the host; and (3) the introduction of endogenous microbes that affect life-span and vector capacity of the new hosts in insect populations. This work reviews current knowledge on microbial symbiosis in mosquitoes that holds promise for development of symbiotic control for mosquito borne diseases. PMID:23265608

  7. ChAd63-MVA-vectored blood-stage malaria vaccines targeting MSP1 and AMA1: assessment of efficacy against mosquito bite challenge in humans.

    PubMed

    Sheehy, Susanne H; Duncan, Christopher J A; Elias, Sean C; Choudhary, Prateek; Biswas, Sumi; Halstead, Fenella D; Collins, Katharine A; Edwards, Nick J; Douglas, Alexander D; Anagnostou, Nicholas A; Ewer, Katie J; Havelock, Tom; Mahungu, Tabitha; Bliss, Carly M; Miura, Kazutoyo; Poulton, Ian D; Lillie, Patrick J; Antrobus, Richard D; Berrie, Eleanor; Moyle, Sarah; Gantlett, Katherine; Colloca, Stefano; Cortese, Riccardo; Long, Carole A; Sinden, Robert E; Gilbert, Sarah C; Lawrie, Alison M; Doherty, Tom; Faust, Saul N; Nicosia, Alfredo; Hill, Adrian V S; Draper, Simon J

    2012-12-01

    The induction of cellular immunity, in conjunction with antibodies, may be essential for vaccines to protect against blood-stage infection with the human malaria parasite Plasmodium falciparum. We have shown that prime-boost delivery of P. falciparum blood-stage antigens by chimpanzee adenovirus 63 (ChAd63) followed by the attenuated orthopoxvirus MVA is safe and immunogenic in healthy adults. Here, we report on vaccine efficacy against controlled human malaria infection delivered by mosquito bites. The blood-stage malaria vaccines were administered alone, or together (MSP1+AMA1), or with a pre-erythrocytic malaria vaccine candidate (MSP1+ME-TRAP). In this first human use of coadministered ChAd63-MVA regimes, we demonstrate immune interference whereby responses against merozoite surface protein 1 (MSP1) are dominant over apical membrane antigen 1 (AMA1) and ME-TRAP. We also show that induction of strong cellular immunity against MSP1 and AMA1 is safe, but does not impact on parasite growth rates in the blood. In a subset of vaccinated volunteers, a delay in time to diagnosis was observed and sterilizing protection was observed in one volunteer coimmunized with MSP1+AMA1-results consistent with vaccine-induced pre-erythrocytic, rather than blood-stage, immunity. These data call into question the utility of T cell-inducing blood-stage malaria vaccines and suggest that the focus should remain on high-titer antibody induction against susceptible antigen targets. PMID:23089736

  8. ChAd63-MVA–vectored Blood-stage Malaria Vaccines Targeting MSP1 and AMA1: Assessment of Efficacy Against Mosquito Bite Challenge in Humans

    PubMed Central

    Sheehy, Susanne H; Duncan, Christopher JA; Elias, Sean C; Choudhary, Prateek; Biswas, Sumi; Halstead, Fenella D; Collins, Katharine A; Edwards, Nick J; Douglas, Alexander D; Anagnostou, Nicholas A; Ewer, Katie J; Havelock, Tom; Mahungu, Tabitha; Bliss, Carly M; Miura, Kazutoyo; Poulton, Ian D; Lillie, Patrick J; Antrobus, Richard D; Berrie, Eleanor; Moyle, Sarah; Gantlett, Katherine; Colloca, Stefano; Cortese, Riccardo; Long, Carole A; Sinden, Robert E; Gilbert, Sarah C; Lawrie, Alison M; Doherty, Tom; Faust, Saul N; Nicosia, Alfredo; Hill, Adrian VS; Draper, Simon J

    2012-01-01

    The induction of cellular immunity, in conjunction with antibodies, may be essential for vaccines to protect against blood-stage infection with the human malaria parasite Plasmodium falciparum. We have shown that prime-boost delivery of P. falciparum blood-stage antigens by chimpanzee adenovirus 63 (ChAd63) followed by the attenuated orthopoxvirus MVA is safe and immunogenic in healthy adults. Here, we report on vaccine efficacy against controlled human malaria infection delivered by mosquito bites. The blood-stage malaria vaccines were administered alone, or together (MSP1+AMA1), or with a pre-erythrocytic malaria vaccine candidate (MSP1+ME-TRAP). In this first human use of coadministered ChAd63-MVA regimes, we demonstrate immune interference whereby responses against merozoite surface protein 1 (MSP1) are dominant over apical membrane antigen 1 (AMA1) and ME-TRAP. We also show that induction of strong cellular immunity against MSP1 and AMA1 is safe, but does not impact on parasite growth rates in the blood. In a subset of vaccinated volunteers, a delay in time to diagnosis was observed and sterilizing protection was observed in one volunteer coimmunized with MSP1+AMA1—results consistent with vaccine-induced pre-erythrocytic, rather than blood-stage, immunity. These data call into question the utility of T cell-inducing blood-stage malaria vaccines and suggest that the focus should remain on high-titer antibody induction against susceptible antigen targets. PMID:23089736

  9. RIFT VALLEY FEVER: PREPARING FOR POTENTIAL NEW MOSQUITO-BORNE DISEASES IN THE U.S. WITH A VECTOR SURVEILLANCE SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this symposium we have discussed four diseases that are emerging threats in the U.S., and it may be concluded that in our best defense knowing the vector is as important as knowing the disease. Rift Valley fever, Dengue, and JEE are but a few of the many emerging diseases that we can prepare for...

  10. Anopheles plumbeus (Diptera: Culicidae) in Europe: a mere nuisance mosquito or potential malaria

    E-print Network

    Boyer, Edmond

    Anopheles plumbeus (Diptera: Culicidae) in Europe: a mere nuisance mosquito or potential malaria vector? Schaffner et al. Schaffner et al. Malaria Journal 2012, 11:393 http mosquito or potential malaria vector? Francis Schaffner1* , Isabelle Thiéry2 , Christian Kaufmann1 , Agnès

  11. Use of geographic information systems to depict and analyze mosquito population trends.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes transmit (vector) disease agents that cause malaria, yellow fever, dengue, West Nile fever, and encephalitis. Spread of these diseases is controlled by the management of mosquito population levels, changes in which are monitored in vector surveillance programs by the use of mechanical tr...

  12. Insecticide resistance in Culex pipiens quinquefasciatus and Aedes albopictus mosquitoes from La Réunion Island

    Microsoft Academic Search

    Michaël Luciano Tantely; Pablo Tortosa; Haoues Alout; Claire Berticat; Arnaud Berthomieu; Abdoul Rutee; Jean-Sébastien Dehecq; Patrick Makoundou; Pierrick Labbé; Nicole Pasteur; Mylène Weill

    2010-01-01

    Resistance to insecticides was monitored on Culex pipiens quinquefasciatus mosquitoes collected in twelve localities of La Réunion, a geographically isolated island of the Indian Ocean. This mosquito is of medical concern in the region as a known vector for filariasis and a potential vector for West Nile and Rift Valley Fever viruses. Our bioassays indicated the presence of resistance to

  13. The Mosquito Melanization Response Is Implicated in Defense against the Entomopathogenic Fungus Beauveria bassiana

    PubMed Central

    Osta, Mike A.

    2012-01-01

    Mosquito immunity studies have focused mainly on characterizing immune effector mechanisms elicited against parasites, bacteria and more recently, viruses. However, those elicited against entomopathogenic fungi remain poorly understood, despite the ubiquitous nature of these microorganisms and their unique invasion route that bypasses the midgut epithelium, an important immune tissue and physical barrier. Here, we used the malaria vector Anopheles gambiae as a model to investigate the role of melanization, a potent immune effector mechanism of arthropods, in mosquito defense against the entomopathogenic fungus Beauveria bassiana, using in vivo functional genetic analysis and confocal microscopy. The temporal monitoring of fungal growth in mosquitoes injected with B. bassiana conidia showed that melanin eventually formed on all stages, including conidia, germ tubes and hyphae, except the single cell hyphal bodies. Nevertheless, melanin rarely aborted the growth of any of these stages and the mycelium continued growing despite being melanized. Silencing TEP1 and CLIPA8, key positive regulators of Plasmodium and bacterial melanization in A. gambiae, abolished completely melanin formation on hyphae but not on germinating conidia or germ tubes. The detection of a layer of hemocytes surrounding germinating conidia but not hyphae suggested that melanization of early fungal stages is cell-mediated while that of late stages is a humoral response dependent on TEP1 and CLIPA8. Microscopic analysis revealed specific association of TEP1 with surfaces of hyphae and the requirement of both, TEP1 and CLIPA8, for recruiting phenoloxidase to these surfaces. Finally, fungal proliferation was more rapid in TEP1 and CLIPA8 knockdown mosquitoes which exhibited increased sensitivity to natural B. bassiana infections than controls. In sum, the mosquito melanization response retards significantly B. bassiana growth and dissemination, a finding that may be exploited to design transgenic fungi with more potent bio-control activities against mosquitoes. PMID:23166497

  14. The impact of uniform and mixed species blood meals on the fitness of the mosquito vector Anopheles gambiae s.s: does a specialist pay for diversifying its host species diet?

    PubMed

    Lyimo, I N; Keegan, S P; Ranford-Cartwright, L C; Ferguson, H M

    2012-03-01

    We investigated the fitness consequences of specialization in an organism whose host choice has an immense impact on human health: the African malaria vector Anopheles gambiae s.s. We tested whether this mosquito's specialism on humans can be attributed to the relative fitness benefits of specialist vs. generalist feeding strategies by contrasting their fecundity and survival on human-only and mixed host diets consisting of blood meals from humans and animals. When given only one blood meal, An. gambiae s.s. survived significantly longer on human and bovine blood, than on canine or avian blood. However, when blood fed repeatedly, there was no evidence that the fitness of An. gambiae s.s. fed a human-only diet was greater than those fed generalist diets. This suggests that the adoption of generalist host feeding strategies in An. gambiae s.s. is not constrained by intraspecific variation in the resource quality of blood from other available host species. PMID:22221693

  15. Analysing the generality of spatially predictive mosquito habitat models

    PubMed Central

    Li, Li; Bian, Ling; Yakob, Laith; Zhou, Guofa; Yan, Guiyun

    2013-01-01

    The increasing spread of multi-drug resistant malaria in African highlands has highlighted the importance of malaria suppression through vector control. Its historical success has meant that larval control has been proposed as part of an integrated malaria vector control program. Due to high operation costs, larval control activities would benefit greatly if the locations of mosquito habitats could be identified quickly and easily, allowing for focal habitat source suppression. Several mosquito habitat models have been developed to predict the location of mosquito habitats. However, to what extent these models can be generalised across time and space to predict the distribution of dynamic mosquito habitats remains largely unexplored. This study used mosquito habitat data collected in six different time periods and four different modelling approaches to establish 24 mosquito habitat models. We systematically tested the generality of these 24 mosquito habitat models. We found that although habitat–environment relationships change temporally, a modest level of performance was attained when validating the models using data collected from different time periods. We also describe flexible approaches to the predictive modelling of mosquito habitats, that provide novel modelling architecture for future research efforts. PMID:21527240

  16. Reduced survival and reproductive success generates selection pressure for the dengue mosquito Aedes aegypti to evolve resistance against infection by the microsporidian parasite Vavraia culicis.

    PubMed

    Sy, Victoria E; Agnew, Philip; Sidobre, Christine; Michalakis, Yannis

    2014-04-01

    The success and sustainability of control measures aimed at reducing the transmission of mosquito-borne diseases will depend on how they influence the fitness of mosquitoes in targeted populations. We investigated the effects of the microsporidian parasite Vavraia culicis on the survival, blood-feeding behaviour and reproductive success of female Aedes aegypti mosquitoes, the main vector of dengue. Infection reduced survival to adulthood and increased adult female mosquito age-dependent mortality relative to uninfected individuals; this additional mortality was closely correlated with the number of parasite spores they harboured when they died. In the first gonotrophic cycle, infected females were less likely to blood-feed, took smaller meals when they did so, and developed fewer eggs than uninfected females. Even though the conditions of this laboratory study favoured minimal developmental times, the costs of infection were already being experienced by the time females reached an age at which they could first reproduce. These results suggest there will be selection pressure for mosquitoes to evolve resistance against this pathogen if it is used as an agent in a control program to reduce the transmission of mosquito-borne human diseases. PMID:24822081

  17. Mosquito-Disseminated Pyriproxyfen Yields High Breeding-Site Coverage and Boosts Juvenile Mosquito Mortality at the Neighborhood Scale

    PubMed Central

    Abad-Franch, Fernando; Zamora-Perea, Elvira; Ferraz, Gonçalo; Padilla-Torres, Samael D.; Luz, Sérgio L. B.

    2015-01-01

    Background Mosquito-borne pathogens pose major public health challenges worldwide. With vaccines or effective drugs still unavailable for most such pathogens, disease prevention heavily relies on vector control. To date, however, mosquito control has proven difficult, with low breeding-site coverage during control campaigns identified as a major drawback. A novel tactic exploits the egg-laying behavior of mosquitoes to have them disseminate tiny particles of a potent larvicide, pyriproxyfen (PPF), from resting to breeding sites, thus improving coverage. This approach has yielded promising results at small spatial scales, but its wider applicability remains unclear. Methodology/Principal Findings We conducted a four-month trial within a 20-month study to investigate mosquito-driven dissemination of PPF dust-particles from 100 ‘dissemination stations’ (DSs) deployed in a 7-ha sub-area to surveillance dwellings and sentinel breeding sites (SBSs) distributed over an urban neighborhood of about 50 ha. We assessed the impact of the trial by measuring juvenile mosquito mortality and adult mosquito emergence in each SBS-month. Using data from 1,075 dwelling-months, 2,988 SBS-months, and 29,922 individual mosquitoes, we show that mosquito-disseminated PPF yielded high coverage of dwellings (up to 100%) and SBSs (up to 94.3%). Juvenile mosquito mortality in SBSs (about 4% at baseline) increased by over one order of magnitude during PPF dissemination (about 75%). This led to a >10-fold decrease of adult mosquito emergence from SBSs, from approximately 1,000–3,000 adults/month before to about 100 adults/month during PPF dissemination. Conclusions/Significance By expanding breeding-site coverage and boosting juvenile mosquito mortality, a strategy based on mosquito-disseminated PPF has potential to substantially enhance mosquito control. Sharp declines in adult mosquito emergence can lower vector/host ratios, reducing the risk of disease outbreaks. This approach is a very promising complement to current and novel mosquito control strategies; it will probably be especially relevant for the control of urban disease vectors, such as Aedes and Culex species, that often cause large epidemics. PMID:25849040

  18. Malaria Mosquitoes Attracted by Fatal Fungus

    PubMed Central

    George, Justin; Jenkins, Nina E.; Blanford, Simon; Thomas, Matthew B.; Baker, Thomas C.

    2013-01-01

    Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors. PMID:23658757

  19. Ecology of Larval Mosquitoes, with Special Reference to Anopheles arabiensis (Diptera: Culcidae) in Market-Garden Wells in

    E-print Network

    Thioulouse, Jean

    -garden wells that provide permanent sites for mosquito larvae, in particular Anopheles arabiensis Patton, the major vector of malaria. A study of the bioecology of mosquito larvae was conducted over 1 yrEcology of Larval Mosquitoes, with Special Reference to Anopheles arabiensis (Diptera: Culcidae

  20. Protection from UV-B Damage of Mosquito Larvicidal Toxins from Bacillus thuringiensis subsp. israelensis Expressed in

    E-print Network

    Zaritsky, Arieh

    that penetrates Earth's ozone layer. This organism, which serves as a food source to mosquito larvae and could to control larvae of mosquitoes and black flies, vectors of many human infectious dis- eases and a nuisanceProtection from UV-B Damage of Mosquito Larvicidal Toxins from Bacillus thuringiensis subsp

  1. The Fat Body Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre-and Post-Blood Meal

    E-print Network

    Houde, Peter

    The Fat Body Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre- and Post- Blood Meal Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre- and Post- Blood Meal. PLoS ONE 6(7): e22573. doi@nmsu.edu Introduction The yellow fever mosquito, Aedes aegypti, is the primary vector for dengue fever, several

  2. In silico evidence for the species-specific conservation of mosquito retroposons: implications as a molecular biomarker

    Microsoft Academic Search

    Wilson Byarugaba; Henry Kajumbula; Misaki Wayengera

    2009-01-01

    BACKGROUND: Mosquitoes are the transmissive vectors for several infectious pathogens that affect man. However, the control of mosquitoes through insecticide and pesticide spraying has proved difficult in the past. We hypothesized that, by virtue of their reported vertical inheritance among mosquitoes, group II introns – a class of small coding ribonucleic acids (scRNAs) – may form a potential species-specific biomarker.

  3. Dengue Vectors and their Spatial Distribution

    PubMed Central

    Higa, Yukiko

    2011-01-01

    The distribution of dengue vectors, Ae. aegypti and Ae. albopictus, is affected by climatic factors. In addition, since their life cycles are well adapted to the human environment, environmental changes resulting from human activity such as urbanization exert a great impact on vector distribution. The different responses of Ae. aegypti and Ae albopictus to various environments result in a difference in spatial distribution along north-south and urban-rural gradients, and between the indoors and outdoors. In the north-south gradient, climate associated with survival is an important factor in spatial distribution. In the urban-rural gradient, different distribution reflects a difference in adult niches and is modified by geographic and human factors. The direct response of the two species to the environment around houses is related to different spatial distribution indoors and outdoors. Dengue viruses circulate mainly between human and vector mosquitoes, and the vector presence is a limiting factor of transmission. Therefore, spatial distribution of dengue vectors is a significant concern in the epidemiology of the disease. Current technologies such as GIS, satellite imagery and statistical models allow researchers to predict the spatial distribution of vectors in the changing environment. Although it is difficult to confirm the actual effect of environmental and climate changes on vector abundance and vector-borne diseases, environmental changes caused by humans and human behavioral changes due to climate change can be expected to exert an impact on dengue vectors. Longitudinal monitoring of dengue vectors and viruses is therefore necessary. PMID:22500133

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

    Microsoft Academic Search

    Hoang Kim Phuc; Morten H Andreasen; Rosemary S Burton; Céline Vass; Matthew J Epton; Gavin Pape; Guoliang Fu; Kirsty C Condon; Sarah Scaife; Christl A Donnelly; Paul G Coleman; Helen White-Cooper; Luke Alphey

    2007-01-01

    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

  5. Mosquito Control Around the Home

    E-print Network

    Jackman, John A.; Olson, Jimmy K.

    2003-03-17

    This leaflet explains how to reduce mosquito problems by eliminating breeding sites for larvae, controlling adult mosquitoes, avoiding contact with mosquitoes and treating larval breeding sites. Long-term control is also discussed....

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

    PubMed

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

    2014-01-01

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

  7. Mosquito Distribution Maps

    NSDL National Science Digital Library

    Greg Shirah

    2002-10-09

    These maps show mosquito habitat distribution for four mosquito species. The red-black areas are results of satellite data analysis showing where particular species of mosquitos can be found. The yellow lines are the published boundaries for where these species can be found. There is a strong correlation between the two. These images were created in support of a story describing how NASA is assisting the CDC and EPA in tracking the spread of West Nile Virus.

  8. Mosquito Infection Responses to Developing Filarial Worms

    PubMed Central

    Erickson, Sara M.; Xi, Zhiyong; Mayhew, George F.; Ramirez, Jose L.; Aliota, Matthew T.; Christensen, Bruce M.; Dimopoulos, George

    2009-01-01

    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 (?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. PMID:19823571

  9. Mosquito-bacteria symbiosis: the case of Anopheles gambiae and Asaia.

    PubMed

    Damiani, Claudia; Ricci, Irene; Crotti, Elena; Rossi, Paolo; Rizzi, Aurora; Scuppa, Patrizia; Capone, Aida; Ulissi, Ulisse; Epis, Sara; Genchi, Marco; Sagnon, N'Fale; Faye, Ingrid; Kang, Angray; Chouaia, Bessem; Whitehorn, Cheryl; Moussa, Guelbeogo W; Mandrioli, Mauro; Esposito, Fulvio; Sacchi, Luciano; Bandi, Claudio; Daffonchio, Daniele; Favia, Guido

    2010-10-01

    The symbiotic relationship between Asaia, an ?-proteobacterium belonging to the family Acetobacteriaceae, and mosquitoes has been studied mainly in the Asian malaria vector Anopheles stephensi. Thus, we have investigated the nature of the association between Asaia and the major Afro-tropical malaria vector Anopheles gambiae. We have isolated Asaia from different wild and laboratory reared colonies of A. gambiae, and it was detected by PCR in all the developmental stages of the mosquito and in all the specimens analyzed. Additionally, we have shown that it localizes in the midgut, salivary glands and reproductive organs. Using recombinant strains of Asaia expressing fluorescent proteins, we have demonstrated the ability of the bacterium to colonize A. gambiae mosquitoes with a pattern similar to that described for A. stephensi. Finally, fluorescent in situ hybridization on the reproductive tract of females of A. gambiae showed a concentration of Asaia at the very periphery of the eggs, suggesting that transmission of Asaia from mother to offspring is likely mediated by a mechanism of egg-smearing. We suggest that Asaia has potential for use in the paratransgenic control of malaria transmitted by A. gambiae. PMID:20571792

  10. Analyzing Mosquito (Diptera: Culicidae) Diversity in Pakistan by DNA Barcoding

    PubMed Central

    Ashfaq, Muhammad; Hebert, Paul D. N.; Mirza, Jawwad H.; Khan, Arif M.; Zafar, Yusuf; Mirza, M. Sajjad

    2014-01-01

    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. PMID:24827460

  11. Field efficacy of a new mosaic long-lasting mosquito net (PermaNet® 3.0) against pyrethroid-resistant malaria vectors: a multi centre study in Western and Central Africa

    PubMed Central

    2010-01-01

    Background Due to the spread of pyrethroid-resistance in malaria vectors in Africa, new strategies and tools are urgently needed to better control malaria transmission. The aim of this study was to evaluate the performances of a new mosaic long-lasting insecticidal net (LLIN), i.e. PermaNet® 3.0, against wild pyrethroid-resistant Anopheles gambiae s.l. in West and Central Africa. Methods A multi centre experimental hut trial was conducted in Malanville (Benin), Vallée du Kou (Burkina Faso) and Pitoa (Cameroon) to investigate the exophily, blood feeding inhibition and mortality induced by PermaNet® 3.0 (i.e. a mosaic net containing piperonyl butoxide and deltamethrin on the roof) comparatively to the WHO recommended PermaNet® 2.0 (unwashed and washed 20-times) and a conventionally deltamethrin-treated net (CTN). Results The personal protection and insecticidal activity of PermaNet 3.0 and PermaNet® 2.0 were excellent (>80%) in the "pyrethroid-tolerant" area of Malanville. In the pyrethroid-resistance areas of Pitoa (metabolic resistance) and Vallée du Kou (presence of the L1014F kdr mutation), PermaNet® 3.0 showed equal or better performances than PermaNet® 2.0. It should be noted however that the deltamethrin content on PermaNet® 3.0 was up to twice higher than that of PermaNet® 2.0. Significant reduction of efficacy of both LLIN was noted after 20 washes although PermaNet® 3.0 still fulfilled the WHO requirement for LLIN. Conclusion The use of combination nets for malaria control offers promising prospects. However, further investigations are needed to demonstrate the benefits of using PermaNet® 3.0 for the control of pyrethroid resistant mosquito populations in Africa. PMID:20423479

  12. Amazonian malaria: Asymptomatic human reservoirs, diagnostic challenges, environmentally-driven changes in mosquito vector populations, and the mandate for sustainable control strategies

    PubMed Central

    da Silva-Nunes, Mônica; Moreno, Marta; Conn, Jan E.; Gamboa, Dionicia; Abeles, Shira; Vinetz, Joseph M.; Ferreira, Marcelo U.

    2012-01-01

    Across the Americas and the Caribbean, nearly 561,000 slide-confirmed malaria infections were reported officially in 2008. The nine Amazonian countries accounted for 89% of these infections; Brazil and Peru alone contributed 56% and 7% of them, respectively. Local populations of the relatively neglected parasite P. vivax, which currently accounts for 77% of the regional malaria burden, are extremely diverse genetically and geographically structured. At a time when malaria elimination is placed on the public health agenda of several endemic countries, it remains unclear why malaria proved so difficult to control in areas of relatively low levels of transmission such as the Amazon Basin. We hypothesize that asymptomatic parasite carriage and massive environmental changes that affect vector abundance and behavior are major contributors to malaria transmission in epidemiologically diverse areas across the Amazon Basin. Here we review available data supporting this hypothesis and discuss their implications for current and future malaria intervention policies in the region. Given that locally generated scientific evidence is urgently required to support malaria control interventions in Amazonia, we briefly describe the aims of our current field-oriented malaria research in rural villages and gold-mining enclaves in Peru and a recently opened agricultural settlement in Brazil. PMID:22015425

  13. Complex effects of temperature on mosquito immune function

    PubMed Central

    Murdock, C. C.; Paaijmans, Krijn P.; Bell, Andrew S.; King, Jonas G.; Hillyer, Julián F.; Read, Andrew F.; Thomas, Matthew B.

    2012-01-01

    Over the last 20 years, ecological immunology has provided much insight into how environmental factors shape host immunity and host–parasite interactions. Currently, the application of this thinking to the study of mosquito immunology has been limited. Mechanistic investigations are nearly always conducted under one set of conditions, yet vectors and parasites associate in a variable world. We highlight how environmental temperature shapes cellular and humoral immune responses (melanization, phagocytosis and transcription of immune genes) in the malaria vector, Anopheles stephensi. Nitric oxide synthase expression peaked at 30°C, cecropin expression showed no main effect of temperature and humoral melanization, and phagocytosis and defensin expression peaked around 18°C. Further, immune responses did not simply scale with temperature, but showed complex interactions between temperature, time and nature of immune challenge. Thus, immune patterns observed under one set of conditions provide little basis for predicting patterns under even marginally different conditions. These quantitative and qualitative effects of temperature have largely been overlooked in vector biology but have significant implications for extrapolating natural/transgenic resistance mechanisms from laboratory to field and for the efficacy of various vector control tools. PMID:22593107

  14. Title: Exploring Mosquito Larval Immunity upon Exposure to Larvicidal Bacillus Sphaericus

    E-print Network

    Johnson, Eric E.

    microenvironment. Mosquito immunity studies have been mainly focusing on the adults. Larva-pathogen interaction1 of 2 Title: Exploring Mosquito Larval Immunity upon Exposure to Larvicidal Bacillus Sphaericus interactions among mosquito gut microbiota, Plasmodium, and host immunity in the context of gut

  15. The basic rules and methods of mosquito rearing (Aedes aegypti)

    PubMed Central

    Imam, Hashmat; Zarnigar; Sofi, Ghulamuddin; Seikh, Aziz

    2014-01-01

    The rearing of Aedes mosquitoes is complex and demanding for several reasons. Aedes larvae are affected by temperature, density and available nutrition, mating is not necessarily accomplished naturally and females need a blood meal to develop eggs. The climate chambers where the mosquitoes are kept are warm and sweaty. Due to these tropical conditions the larvae develop fast and need to be cared for daily. The Laboratory of Entomology in National Institute of Malaria Research Bangalore has cultured different colonies of different vectors successfully. In this paper, we discuss different aspects off the rearing process which affect mosquito fitness and are of importance for the quality of fundamental and applied research. PMID:24754030

  16. Venezuelan equine encephalitis virus infection of mosquito cells requires acidification as well as mosquito homologs of the endocytic proteins Rab5 and Rab7

    Microsoft Academic Search

    Tonya M. Colpitts; Andrew C. Moore; Andrey A. Kolokoltsov; Robert A. Davey

    2007-01-01

    Venezuelan equine encephalitis virus (VEEV) is a New World alphavirus that can cause fatal encephalitis in humans. It remains a naturally emerging disease as well as a highly developed biological weapon. VEEV is transmitted to humans in nature by mosquito vectors. Little is known about VEEV entry, especially in mosquito cells. Here, a novel luciferase-based virus entry assay is used

  17. Transstadial Transmission of Francisella tularensis holarctica in Mosquitoes, Sweden

    PubMed Central

    Andersson, Ann-Christin; Bäckman, Stina; Schäfer, Martina L.; Forsman, Mats; Thelaus, Johanna

    2011-01-01

    In Sweden, human cases of tularemia caused by Francisella tularensis holarctica are assumed to be transmitted by mosquitoes, but how mosquito vectors acquire and transmit the bacterium is not clear. To determine how transmission of this bacterium occurs, mosquito larvae were collected in an area where tularemia is endemic, brought to the laboratory, and reared to adults in their original pond water. Screening of adult mosquitoes by real-time PCR demonstrated F. tularensis lpnA sequences in 14 of the 48 mosquito pools tested; lpnA sequences were demonstrated in 6 of 9 identified mosquito species. Further analysis confirmed the presence of F. tularensis holarctica–specific 30-bp deletion region sequences (FtM19inDel) in water from breeding containers and in 3 mosquito species (Aedes sticticus, Ae. vexans, and Ae. punctor) known to take blood from humans. Our results suggest that the mosquitoes that transmit F. tularensis holarctica during tularemia outbreaks acquire the bacterium already as larvae. PMID:21529386

  18. Green-synthesized silver nanoparticles as a novel control tool against dengue virus (DEN-2) and its primary vector Aedes aegypti

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dengue is an arthropod-borne viral infection mainly vectored through the bite of Aedes mosquitoes. Recently, its transmission has strongly increased in urban and semi-urban areas of tropical and sub-tropical regions worldwide, becoming a major international public health concern. There is no specifi...

  19. Using remote sensing to map larval and adult populations of Anopheles hyrcanus (Diptera: Culicidae) a potential malaria vector in Southern France

    Microsoft Academic Search

    Annelise Tran; Nicolas Ponçon; Céline Toty; Catherine Linard; Hélène Guis; Jean-Baptiste Ferré; Danny Lo Seen; François Roger; Stéphane de la Rocque; Didier Fontenille; Thierry Baldet

    2008-01-01

    BACKGROUND: Although malaria disappeared from southern France more than 60 years ago, suspicions of recent autochthonous transmission in the French Mediterranean coast support the idea that the area could still be subject to malaria transmission. The main potential vector of malaria in the Camargue area, the largest river delta in southern France, is the mosquito Anopheles hyrcanus (Diptera: Culicidae). In

  20. Effects of Local Anthropogenic Changes on Potential Malaria Vector Anopheles hyrcanus and West Nile Virus Vector Culex modestus, Camargue, France

    PubMed Central

    Ponçon, Nicolas; Balenghien, Thomas; Toty, Céline; Ferré, Jean Baptiste; Thomas, Cyrille; Dervieux, Alain; L’Ambert, Grégory; Schaffner, Francis; Bardin, Olivier

    2007-01-01

    Using historical data, we highlight the consequences of anthropogenic ecosystem modifications on the abundance of mosquitoes implicated as the current most important potential malaria vector, Anopheles hyrcanus, and the most important West Nile virus (WNV) vector, Culex modestus, in the Camargue region, France. From World War II to 1971, populations of these species increased as rice cultivation expanded in the region in a political context that supported agriculture. They then fell, likely because of decreased cultivation and increased pesticide use to control a rice pest. The species increased again after 2000 with the advent of more targeted pest-management strategies, mainly the results of European regulations decisions. An intertwined influence of political context, environmental constraints, technical improvements, and social factors led to changes in mosquito abundance that had potential consequences on malaria and WNV transmission. These findings suggest that anthropogenic changes should not be underestimated in vectorborne disease recrudescence. PMID:18258028

  1. Effects of local anthropogenic changes on potential malaria vector Anopheles hyrcanus and West Nile virus vector Culex modestus, Camargue, France.

    PubMed

    Ponçon, Nicolas; Balenghien, Thomas; Toty, Céline; Baptiste Ferré, Jean; Thomas, Cyrille; Dervieux, Alain; L'ambert, Grégory; Schaffner, Francis; Bardin, Olivier; Fontenille, Didier

    2007-12-01

    Using historical data, we highlight the consequences of anthropogenic ecosystem modifications on the abundance of mosquitoes implicated as the current most important potential malaria vector, Anopheles hyrcanus, and the most important West Nile virus (WNV) vector, Culex modestus, in the Camargue region, France. From World War II to 1971, populations of these species increased as rice cultivation expanded in the region in a political context that supported agriculture. They then fell, likely because of decreased cultivation and increased pesticide use to control a rice pest. The species increased again after 2000 with the advent of more targeted pest-management strategies, mainly the results of European regulations decisions. An intertwined influence of political context, environmental constraints, technical improvements, and social factors led to changes in mosquito abundance that had potential consequences on malaria and WNV transmission. These findings suggest that anthropogenic changes should not be underestimated in vectorborne disease recrudescence. PMID:18258028

  2. Dry season refugia for anopheline larvae and mapping of the seasonal distribution in mosquito larval habitats in Kandi, northeastern Benin

    PubMed Central

    2014-01-01

    Background The dynamics of mosquito populations depends on availability of suitable surface water for oviposition. It is well known that suitable management of mosquito larval habitats in the sub-Saharan countries, particularly during droughts, could help to suppress vector densities and malaria transmission. We conducted a field survey to investigate the spatial and seasonal distribution of mosquito larval habitats and identify drought-refugia for anopheline larvae. Methods A GIS approach was used to identify, geo-reference and follow up longitudinally from May 2012 to May 2013, all mosquito breeding sites in two rural sites (Yondarou and Thui), one urban (Kossarou), and one peri-urban (Pèdè) site at Kandi, a municipality in northeastern Benin. In Kandi, droughts are excessive with no rain for nearly six months and a lot of sunshine. A comprehensive record of mosquito larval habitats was conducted periodically in all sites for the identification of drought-refugia of anopheline larval stages. With geospatialisation data, seasonal larval distribution maps were generated for each study site with the software ArcGIS version 10.2. Results Overall, 187 mosquito breeding sites were identified of which 29.95% were recorded during drought. In rural, peri-urban and urban sites, most of the drought-refugia of anopheline larvae were domestic in nature (61.54%). Moreover, in rural settings, anopheline larvae were also sampled in cisterns and wells (25% of larval habitats sampled during drought in Yondarou and 20% in Thui). The mapping showed a significant decrease in the spatial distribution of mosquito larval habitats in rural, peri-urban and urban sites during drought, except in Yondarou (rural) where the aridity did not seem to influence the distribution of larval habitats. Conclusion Our data showed that the main drought-refugia of anopheline larvae were of a domestic nature as well as wells and cisterns. A suitable management of mosquito larvae in sub-Saharan countries, particularly during droughts, should target such larval habitats for a meaningful impact on the dynamics of mosquito populations and malaria transmission. PMID:24684886

  3. A geographical information system-based multicriteria evaluation to map areas at risk for Rift Valley fever vector-borne transmission in Italy.

    PubMed

    Tran, A; Ippoliti, C; Balenghien, T; Conte, A; Gely, M; Calistri, P; Goffredo, M; Baldet, T; Chevalier, V

    2013-11-01

    Rift Valley fever (RVF) is a severe mosquito-borne disease that is caused by a Phlebovirus (Bunyaviridae) and affects domestic ruminants and humans. Recently, its distribution widened, threatening Europe. The probability of the introduction and large-scale spread of Rift Valley fever virus (RVFV) in Europe is low, but localized RVF outbreaks may occur in areas where populations of ruminants and potential vectors are present. In this study, we assumed the introduction of the virus into Italy and focused on the risk of vector-borne transmission of RVFV to three main European potential hosts (cattle, sheep and goats). Five main potential mosquito vectors belonging to the Culex and Aedes genera that are present in Italy were identified in a literature review. We first modelled the geographical distribution of these five species based on expert knowledge and using land cover as a proxy of mosquito presence. The mosquito distribution maps were compared with field mosquito collections from Italy to validate the model. Next, the risk of RVFV transmission was modelled using a multicriteria evaluation (MCE) approach, integrating expert knowledge and the results of a literature review on host sensitivity and vector competence, feeding behaviour and abundance. A sensitivity analysis was performed to assess the robustness of the results with respect to expert choices. The resulting maps include (i) five maps of the vector distribution, (ii) a map of suitable areas for vector-borne transmission of RVFV and (iii) a map of the risk of RVFV vector-borne transmission to sensitive hosts given a viral introduction. Good agreement was found between the modelled presence probability and the observed presence or absence of each vector species. The resulting RVF risk map highlighted strong spatial heterogeneity and could be used to target surveillance. In conclusion, the geographical information system (GIS)-based MCE served as a valuable framework and a flexible tool for mapping the areas at risk of a pathogen that is currently absent from a region. PMID:24589097

  4. Quantifying behavioural interactions between humans and mosquitoes: Evaluating the protective efficacy of insecticidal nets against malaria transmission in rural Tanzania

    Microsoft Academic Search

    Gerry F Killeen; Japhet Kihonda; Edith Lyimo; Fred R Oketch; Maya E Kotas; Evan Mathenge; Joanna A Schellenberg; Christian Lengeler; Thomas A Smith; Chris J Drakeley

    2006-01-01

    BACKGROUND: African malaria vectors bite predominantly indoors at night so sleeping under an Insecticide-Treated Net (ITN) can greatly reduce malaria risk. Behavioural adaptation by mosquitoes to increasing ITN coverage could allow vector mosquitoes to bite outside of peak sleeping hours and undermine efficacy of this key malaria prevention measure. METHODS: High coverage with largely untreated nets has been achieved in

  5. Distribution of mosquito larvae in various breeding sites in National Zoo Malaysia.

    PubMed

    Muhammad-Aidil, R; Imelda, A; Jeffery, J; Ngui, R; Wan Yusoff, W S; Aziz, S; Lim, Y A L; Rohela, M

    2015-03-01

    Mosquitoes are principal vectors of major vector-borne diseases. They are widely found throughout urban and rural areas in Malaysia. They are responsible for various vector-borne diseases such as dengue, malaria, filariasis and encephalitis. A total of 158 mosquito larvae specimens were collected from the National Zoo, Malaysia, from 11 types of breeding habitats during the study period from end of May 2007 to July 2007. Aedes albopictus was the predominant species (35.4%), followed by Tripteroides aranoides (26.6%), Lutzia halifaxii (11.4%), Aedes alboscutellatus (10.1%), Aedes caecus (8.9%), Armigeres spp. (4.4%), Malaya genurostris (2.5%) and Culex vishnui (0.6%). It is important to have a mosquito free environment in a public place like the zoo. Routine larval surveillance should be implemented for an effective mosquito control program in order to reduce mosquito population. PMID:25801269

  6. Play the Mosquito Game

    MedlinePLUS

    ... Malaria MRI Nerve Signaling Pavlov's Dog Split Brain Experiments The Cell and its Organelles The Genetic Code ... caused by a parasite that is transmitted to humans by a female mosquito's bite. Read More » The ...

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

    PubMed

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

    2015-04-01

    Mosquitoes are natural vectors for many etiologic agents of human viral diseases. Mosquito-borne flaviviruses can persistently infect the mosquito central nervous system without causing dramatic pathology or influencing the mosquito behavior and lifespan. The mechanism by which the mosquito nervous system resists flaviviral infection is still largely unknown. Here we report that an Aedes aegypti homologue of the neural factor Hikaru genki (AaHig) efficiently restricts flavivirus infection of the central nervous system. AaHig was predominantly expressed in the mosquito nervous system and localized to the plasma membrane of neural cells. Functional blockade of AaHig enhanced Dengue virus (DENV) and Japanese encephalitis virus (JEV), but not Sindbis virus (SINV), replication in mosquito heads and consequently caused neural apoptosis and a dramatic reduction in the mosquito lifespan. Consistently, delivery of recombinant AaHig to mosquitoes reduced viral infection. Furthermore, the membrane-localized AaHig directly interfaced with a highly conserved motif in the surface envelope proteins of DENV and JEV, and consequently interrupted endocytic viral entry into mosquito cells. Loss of either plasma membrane targeting or virion-binding ability rendered AaHig nonfunctional. Interestingly, Culex pipien pallens Hig also demonstrated a prominent anti-flavivirus activity, suggesting a functionally conserved function for Hig. Our results demonstrate that an evolutionarily conserved antiviral mechanism prevents lethal flaviviral infection of the central nervous system in mosquitoes, and thus may facilitate flaviviral transmission in nature. PMID:25915054

  8. PCR and dissection as tools to monitor filarial infection of Aedes polynesiensis mosquitoes in French Polynesia

    Microsoft Academic Search

    Catherine Plichart; Yves Sechan; Neil Davies; Anne-Marie Legrand

    2006-01-01

    BACKGROUND: Entomological methods may provide important tools for monitoring the transmission of filariasis in French Polynesia. In order to standardize our PCR method and refine our protocol to assess filarial infection levels in mosquitoes, we compared dissection of the vector, Aedes polynesiensis, with the poolscreening polymerase chain reaction (PS-PCR) assay. METHODS: (1) Mosquitoes were collected in human landing catches in

  9. PCR and Mosquito dissection as tools to monitor filarial infection levels following mass treatment

    Microsoft Academic Search

    David S Goodman; Jean-Nicolas Orelus; Jacquelin M Roberts; Patrick J Lammie; Thomas G Streit

    2003-01-01

    BACKGROUND: Entomological methods may provide important tools for monitoring the progress of lymphatic filariasis elimination programs. In this study, we compared dissection of the vector, Culex quinquefasciatus, with the polymerase chain reaction (PCR) to assess filarial infection levels in mosquitoes in the context of a lymphatic filariasis elimination program in Leogane, Haiti. METHODS: Mosquitoes were collected using gravid traps located

  10. The influence of malaria parasite genetic diversity and anaemia on mosquito feeding and fecundity

    E-print Network

    Rivero, Ana

    The influence of malaria parasite genetic diversity and anaemia on mosquito feeding and fecundity H genetics and infection genetic diversity on the fecundity of mosquitoes carrying malaria parasites. The malaria vector Anopheles stephensi was infected with either of 2 different genotypes of the rodent malaria

  11. Mosquito repellent (pyrethroid-based) induced dysfunction of blood–brain barrier permeability in developing brain

    Microsoft Academic Search

    C Sinha; A. K Agrawal; F Islam; K Seth; R. K Chaturvedi; S Shukla; P. K Seth

    2004-01-01

    Pyrethroid-based mosquito repellents (MR) are commonly used to protect humans against mosquito vector. New born babies and children are often exposed to pyrethroids for long periods by the use of liquid vaporizers. Occupational and experimental studies indicate that pyrethroids can cause clinical, biochemical and neurological changes, and that exposure to pyrethroids during organogenesis and early developmental period is especially harmful.

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

    Microsoft Academic Search

    Chris M Cirimotich; Jaclyn C Scott; Aaron T Phillips; Brian J Geiss; Ken E Olson

    2009-01-01

    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

  13. Chikungunya Virus and Aedes Mosquitoes: Saliva Is Infectious as soon as Two Days after Oral Infection

    E-print Network

    Boyer, Edmond

    Chikungunya Virus and Aedes Mosquitoes: Saliva Is Infectious as soon as Two Days after Oral and Aedes albopictus are potential vectors of chikungunya virus (CHIKV). The recent CHIKV outbreaks were: Dubrulle M, Mousson L, Moutailler S, Vazeille M, Failloux A-B (2009) Chikungunya Virus and Aedes Mosquitoes

  14. Multiple chemosensory targets for discovery of novel chemicals for disruption of mosquito behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yellow-fever mosquito Aedes aegypti is an important vector of diseases including dengue fever, yellow fever, chikungunya and West Nile virus. Olfactory and gustatory signals play important roles in the orientation of female mosquitoes to vertebrate hosts and initiation of blood feeding. Using re...

  15. Synergism between ammonia, lactic acid and carboxylic acids as kairomones in the host-seeking behaviour of the malaria mosquito Anopheles gambiae sensu stricto (Diptera: Culicidae)

    Microsoft Academic Search

    Renate C. Smallegange; Yu Tong Qiu; Loon van J. J. A; Willem Takken

    2005-01-01

    Host odours play a major role in the orientation and host location of blood-feeding mosquitoes. Anopheles gambiae Giles sensu stricto, which is the most important malaria vector in Africa, is a highly anthropophilic mosquito species, and the host-seeking behaviour of the females of this mosquito is guided by volatiles of human origin. Ammonia, lactic acid and several carboxylic acids are

  16. Composition of Human Skin Microbiota Affects Attractiveness to Malaria Mosquitoes

    PubMed Central

    Verhulst, Niels O.; Qiu, Yu Tong; Beijleveld, Hans; Maliepaard, Chris; Knights, Dan; Schulz, Stefan; Berg-Lyons, Donna; Lauber, Christian L.; Verduijn, Willem; Haasnoot, Geert W.; Mumm, Roland; Bouwmeester, Harro J.; Claas, Frans H. J.; Dicke, Marcel; van Loon, Joop J. A.; Takken, Willem; Knight, Rob; Smallegange, Renate C.

    2011-01-01

    The African malaria mosquito Anopheles gambiae sensu stricto continues to play an important role in malaria transmission, which is aggravated by its high degree of anthropophily, making it among the foremost vectors of this disease. In the current study we set out to unravel the strong association between this mosquito species and human beings, as it is determined by odorant cues derived from the human skin. Microbial communities on the skin play key roles in the production of human body odour. We demonstrate that the composition of the skin microbiota affects the degree of attractiveness of human beings to this mosquito species. Bacterial plate counts and 16S rRNA sequencing revealed that individuals that are highly attractive to An. gambiae s.s. have a significantly higher abundance, but lower diversity of bacteria on their skin than individuals that are poorly attractive. Bacterial genera that are correlated with the relative degree of attractiveness to mosquitoes were identified. The discovery of the connection between skin microbial populations and attractiveness to mosquitoes may lead to the development of new mosquito attractants and personalized methods for protection against vectors of malaria and other infectious diseases. PMID:22216154

  17. Transmission potential of Rickettsia felis infection by Anopheles gambiae mosquitoes

    PubMed Central

    Dieme, Constentin; Bechah, Yassina; Socolovschi, Cristina; Audoly, Gilles; Berenger, Jean-Michel; Faye, Ousmane; Raoult, Didier; Parola, Philippe

    2015-01-01

    A growing number of recent reports have implicated Rickettsia felis as a human pathogen, paralleling the increasing detection of R. felis in arthropod hosts across the globe, primarily in fleas. Here Anopheles gambiae mosquitoes, the primary malarial vectors in sub-Saharan Africa, were fed with either blood meal infected with R. felis or infected cellular media administered in membrane feeding systems. In addition, a group of mosquitoes was fed on R. felis-infected BALB/c mice. The acquisition and persistence of R. felis in mosquitoes was demonstrated by quantitative PCR detection of the bacteria up to day 15 postinfection. R. felis was detected in mosquito feces up to day 14. Furthermore, R. felis was visualized by immunofluorescence in salivary glands, in and around the gut, and in the ovaries, although no vertical transmission was observed. R. felis was also found in the cotton used for sucrose feeding after the mosquitoes were fed infected blood. Natural bites from R. felis-infected An. gambiae were able to cause transient rickettsemias in mice, indicating that this mosquito species has the potential to be a vector of R. felis infection. This is particularly important given the recent report of high prevalence of R. felis infection in patients with “fever of unknown origin” in malaria-endemic areas. PMID:26056256

  18. Predicting the risk of an endemic focus of Leishmania tropica becoming established in South-Western Europe through the presence of its main vector, Phlebotomus sergenti Parrot, 1917.

    PubMed

    Barón, S D; Morillas-Márquez, F; Morales-Yuste, M; Díaz-Sáez, V; Gállego, M; Molina, R; Martín-Sánchez, J

    2013-09-01

    The aim of the study was the construction of risk maps for exposure to Phlebotomus sergenti, the main vector of Leishmania tropica, with a view to identifying hot spots for the potential establishment of this parasite in the southwest of Europe. Data were collected on the presence/absence of this vector and the ecological and climatic characteristics of 662 sampling sites located in the southeast, centre and northeast of the Iberian Peninsula (south-western Europe). The environmental factors associated with the distribution of P. sergenti were determined. The best predictors for the presence of this dipteran were ‘altitude’, ‘land use’, ‘land surface temperature’, ‘aspect’, ‘adjacent land cover’, ‘absence of vegetation in wall’ and the ‘absence of PVC pipes in the drainage holes of retaining walls’. Risk maps for exposure to the vector were drawn up based on these variables. The validation of the predictive risk model confirmed its usefulness in the detection of areas with a high risk of P. sergenti being present. These locations represent potential hot spots for an autochthonous focus of L. tropica becoming established. The risk maps produced for P. sergenti presence revealed several areas in the centre and south of the Iberian Peninsula to be the most prone to this process, which would make it possible for the disease to enter south-western Europe. PMID:23965821

  19. Evaluation of methods to assess transmission potential of Venezuelan equine encephalitis virus by mosquitoes and estimation of mosquito saliva titers.

    PubMed

    Smith, Darci R; Carrara, Anne-Sophie; Aguilar, Patricia V; Weaver, Scott C

    2005-07-01

    Determining the dose of an arbovirus transmitted by a mosquito is important to design transmission and pathogenesis studies simulating natural infection. Several different artificial infection and transmission methods used to assess vector competence and to estimate the dose injected during mosquito feeding have not been fully evaluated to determine whether they accurately reflect natural transmission. Additionally, it is not known whether different mosquito vectors transmit similar amounts of a given virus. Therefore, we compared three traditional artificial transmission methods using Venezuelan equine encephalitis virus (VEEV) and Aedes albopictus and Ochlerotatus taeniorhynchus mosquitoes. Both the mosquito species and the infection route used affected the amount of virus detected in the saliva after a 10-day extrinsic incubation period. Median titers of virus detected in saliva of Ae. albopictus and Oc. taeniorhynchus mosquitoes ranged from 0.2 to 1.1 log(10) (mean 0.7-1.4 log(10)) and 0.2 to 3.2 log(10) (mean 1.0-3.6 log(10)) plaque-forming units, respectively. The results of this study will aid in the design of transmission and pathogenesis studies involving arboviruses. PMID:16014828

  20. Genetic and environmental determinants of malaria parasite virulence in mosquitoes.

    PubMed Central

    Ferguson, H M; Read, A F

    2002-01-01

    Models of malaria epidemiology and evolution are frequently based on the assumption that vector-parasitic associations are benign. Implicit in this assumption is the supposition that all Plasmodium parasites have an equal and neutral effect on vector survival, and thus that there is no parasite genetic variation for vector virulence. While some data support the assumption of avirulence, there has been no examination of the impact of parasite genetic diversity. We conducted a laboratory study with the rodent malaria parasite, Plasmodium chabaudi and the vector, Anopheles stephensi, to determine whether mosquito mortality varied with parasite genotype (CR and ER clones), infection diversity (single versus mixed genotype) and nutrient availability. Vector mortality varied significantly between parasite genotypes, but the rank order of virulence depended on environmental conditions. In standard conditions, mixed genotype infections were the most virulent but when glucose water was limited, mortality was highest in mosquitoes infected with CR. These genotype-by-environment interactions were repeatable across two experiments and could not be explained by variation in anaemia, gametocytaemia, blood meal size, mosquito body size, infection rate or oocyst burden. Variation in the genetic and environmental determinants of virulence may explain conflicting accounts of Plasmodium pathogenicity to mosquitoes in the malaria literature. PMID:12065037

  1. Proteomic Identification of Dengue Virus Binding Proteins in Aedes aegypti Mosquitoes and Aedes albopictus Cells

    PubMed Central

    Muñoz, Maria de Lourdes; Limón-Camacho, Gustavo; Tovar, Rosalinda; Diaz-Badillo, Alvaro; Mendoza-Hernández, Guillermo; Black, William C.

    2013-01-01

    The main vector of dengue in America is the mosquito Aedes aegypti, which is infected by dengue virus (DENV) through receptors of midgut epithelial cells. The envelope protein (E) of dengue virus binds to receptors present on the host cells through its domain III that has been primarily recognized to bind cell receptors. In order to identify potential receptors, proteins from mosquito midgut tissue and C6/36 cells were purified by affinity using columns with the recombinant E protein domain III (rE-DIII) or DENV particles bound covalently to Sepharose 4B to compare and evaluate their performance to bind proteins including putative receptors from female mosquitoes of Ae. aegypti. To determine their identity mass spectrometric analysis of purified proteins separated by polyacrylamide gel electrophoresis was performed. Our results indicate that both viral particles and rE-DIII bound proteins with the same apparent molecular weights of 57 and 67?kDa. In addition, viral particles bound high molecular weight proteins. Purified proteins identified were enolase, beta-adrenergic receptor kinase (beta-ARK), translation elongation factor EF-1 alpha/Tu, and cadherin. PMID:24324976

  2. Mosquito Problems after a Storm 

    E-print Network

    Johnsen, Mark

    2008-08-05

    Areas flooded after a severe storm are prone to mosquito problems. Several mosquito species are a danger to humans because of the diseases they transmit. This publication explains the symptoms of dengue fever, West Nile virus and St. Louis...

  3. Effects of fipronil on dogs over Triatoma infestans, the main vector of Trypanosoma cruzi, causative agent of Chagas disease.

    PubMed

    Amelotti, Ivana; Catalá, Silvia S; Gorla, David E

    2012-10-01

    Chagas disease is the most important endemic disease in Latin America, mainly transmitted by Triatoma infestans in the Southern Cone countries of South America. Dogs are one of the main domestic reservoirs of Trypanosoma cruzi, the etiological agent of Chagas disease. The presence of dogs in rural households of endemic areas significantly increases the likelihood of the vectorial transmission of the parasite. We studied the mortality and blood intake of T. infestans exposed to dogs treated with different doses and formulations of fipronil. Two doses, two formulations, and different distances to the application point of fipronil were compared. Third instar nymphs of T. infestans were fed at different time intervals after the insecticide application up to 45 days post-application. No significant difference was found between the blood intake of nymphs fed on control and treated dogs with different doses and formulations (p > 0.05). The spray formulation showed lower effect and persistence than the spot-on formulation. The mortality rate caused by the spot-on formulation in the 26.8-mg active ingredient (a.i.)/kg dose was higher (48%) than with the 13.4-mg a.i./kg dose (25%), 24 h after the insecticide application. The effect was highly heterogeneous among replicates of the same treatment. The mortality rate of nymphs fed over the point of the insecticide application was higher than the mortality of nymphs fed over places 12 cm apart from the fipronil application point, suggesting that the distribution of fipronil over the dog body is lower than the needed one to obtain a persistent triatomicide effect. PMID:22669692

  4. Post-integration behavior of a Minos transposon in the malaria mosquito Anopheles stephensi

    Microsoft Academic Search

    Christina Scali; Tony Nolan; Igor Sharakhov; Maria Sharakhova; Andrea Crisanti; Flaminia Catteruccia

    2007-01-01

    Transposable elements represent important tools to perform functional studies in insects. In Drosophila melanogaster, the remobilization properties of transposable elements have been utilized for enhancer-trapping and insertional mutagenesis\\u000a experiments, which have considerably helped in the functional characterization of the fruitfly genome. In Anopheles mosquitoes, the sole vectors of human malaria, as well as in other mosquito vectors of disease, the

  5. British Container Breeding Mosquitoes: The Impact of Urbanisation and Climate Change on Community Composition and Phenology

    PubMed Central

    Townroe, Susannah; Callaghan, Amanda

    2014-01-01

    The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.4±21.3) per container than those in rural containers (77.7±15.1). Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV]) and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector). Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9°C and 1.2°C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK. PMID:24759617

  6. British container breeding mosquitoes: the impact of urbanisation and climate change on community composition and phenology.

    PubMed

    Townroe, Susannah; Callaghan, Amanda

    2014-01-01

    The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.4±21.3) per container than those in rural containers (77.7±15.1). Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV]) and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector). Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9°C and 1.2°C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK. PMID:24759617

  7. Malaria Parasite Development in the Mosquito and Infection of the Mammalian Host

    PubMed Central

    Aly, Ahmed S.I.; Vaughan, Ashley M.; Kappe, Stefan H.I.

    2010-01-01

    Plasmodium sporozoites are the product of a complex developmental process in the mosquito vector and are destined to infect the mammalian liver. Attention has been drawn to the mosquito stages and preerythrocytic stages owing to recognition that these are bottlenecks in the parasite life cycle and that intervention at these stages can block transmission and prevent infection. Parasite progression in the Anopheles mosquito, sporozoite transmission to the mammalian host by mosquito bite, and subsequent infection of the liver are characterized by extensive migration of invasive stages, cell invasion, and developmental changes. Preparation for the liver phase in the mammalian host begins in the mosquito with an extensive reprogramming of the sporozoite to support efficient infection and survival. Here, we discuss what is known about the molecular and cellular basis of the developmental progression of parasites and their interactions with host tissues in the mosquito and during the early phase of mammalian infection. PMID:19575563

  8. The cell biology of malaria infection of mosquito: advances and opportunities.

    PubMed

    Sinden, R E

    2015-04-01

    Recent reviews (Feachem et?al.; Alonso et?al.) have concluded that in order to have a sustainable impact on the global burden of malaria, it is essential that we knowingly reduce the global incidence of infected persons. To achieve this we must reduce the basic reproductive rate of the parasites to mosquitoes relative to the number of persons, the mosquito/human biting rate, the proportion of mosquitoes carrying infectious sporozoites, the daily survival rate of the infectious mosquito and the ability of malaria-infected persons to infect mosquito vectors. This paper focuses on our understanding of parasite biology underpinning the last of these terms: infection of the mosquito. The article attempts to highlight central issues that require further study to assist in the discovery of useful transmission-blocking measures. PMID:25557077

  9. MOSQUITO POPULATIONS IN STORMWATER IMPOUNDMENTS

    E-print Network

    Hunt, William F.

    impoundments in North Carolina found no mosquito larvae or pupae in more than 66 per- cent of the facility of the sedimentation chamber. The oil sheen interferes with the ability of mosquito larvae and pupae to breathe oxygenMOSQUITO POPULATIONS IN STORMWATER IMPOUNDMENTS Several studies conducted across the United States

  10. Trapping of Rift Valley Fever (RVF) vectors using Light Emitting Diode (LED) CDC traps in two arboviral disease hot spots in Kenya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Mosquitoes’ response to artificial lights including color has been exploited in trap designs for improved sampling of mosquito vectors. Earlier studies suggest that mosquitoes are attracted to specific wavelengths of light and thus the need to refine techniques to increase mosquito captu...

  11. REVIEWS AND SYNTHESES Ecology of invasive mosquitoes: effects on resident

    E-print Network

    Juliano, Steven A.

    concentrate on the best-studied invasive mosquito, Aedes albopictus, evaluating the application of basic ecological theory to invasions by Aedes albopictus. We develop a model based on observations of Aedes­host systems. Keywords Aedes albopictus, apparent competition, Culicidae, disease ecology, disease vectors

  12. RESEARCH ARTICLE Open Access Differential responses of the mosquito Aedes

    E-print Network

    Paris-Sud XI, Université de

    -Bella Failloux1* Abstract Background: Aedes aegypti and Aedes albopictus are both vectors of chikungunya virus as the virus could be found in saliva as early as two days after infection. An important question is whether between responses of mosquito species to the two viruses, (2) CHIKV infection only affected significantly

  13. Avian malaria prevalence and mosquito abundance in the Western Cape, South Africa

    PubMed Central

    2013-01-01

    Background The close relationship between vector-borne diseases and their environment is well documented, especially for diseases with water-dependent vectors such as avian malaria. Mosquitoes are the primary vectors of avian malaria and also the definitive hosts in the disease life cycle. Factors pertinent to mosquito ecology are likely to be influential to observed infection patterns; such factors include rainfall, season, temperature, and water quality. Methods The influence of mosquito abundance and occurrence on the prevalence of Plasmodium spp. in the Ploceidae family (weavers) was examined, taking into account factors with an indirect influence upon mosquito ecology. Mosquitoes and weaver blood samples were simultaneously collected in the Western Cape, South Africa over a two-year period, and patterns of vector abundance and infection prevalence were compared. Dissolved oxygen, pH, temperature and salinity measurements were taken at 20 permanent waterbodies. Rainfall during this period was also quantified using remotely sensed data from up to 6 months prior to sampling months. Results Sixteen wetlands had weavers infected with avian malaria. More than half of the mosquitoes caught were trapped at one site; when this site was excluded, the number of mosquitoes trapped did not vary significantly between sites. The majority of mosquitoes collected belonged to the predominant vector species group for avian malaria (Culex culex species complex). Seasonal variation occurred in infection and mosquito prevalence, water pH and water temperature, with greater variability observed in summer than in winter. There was a significant correlation of infection prevalence with rainfall two months prior to sampling months. Mosquito prevalence patterns across the landscape also showed a close relationship to patterns of rainfall. Contrary to predictions, a pattern of asynchronous co-variation occurred between mosquito prevalence and infection prevalence. Conclusion Overall, salinity, rainfall, and mosquito prevalence and season were the most influential vector-related factors on infection prevalence. After comparison with related studies, the tentative conclusion drawn was that patterns of asynchronous variation between malaria prevalence and mosquito abundance were concurrent with those reported in lag response patterns. PMID:24160170

  14. Mosquito blood-meal analysis for avian malaria study in wild bird communities: laboratory verification and application to Culex sasai (Diptera: Culicidae) collected in Tokyo, Japan

    Microsoft Academic Search

    Kyeong Soon Kim; Yoshio Tsuda; Toshinori Sasaki; Mutsuo Kobayashi; Yoshikazu Hirota

    2009-01-01

    We conducted laboratory experiments to verify molecular techniques of avian malaria parasite detection distinguishing between\\u000a an infected mosquito (oocysts on midgut wall) and infective mosquito (sporozoites in salivary glands) in parallel with blood-meal\\u000a identification from individual blood-fed mosquitoes prior to application to field survey for avian malaria. Domestic fowl\\u000a infected with Plasmodium gallinaceum was exposed to a vector and non-vector

  15. Investigations of Koutango Virus Infectivity and Dissemination Dynamics in Aedes aegypti Mosquitoes

    PubMed Central

    de Araújo Lobo, Jaime M; Christofferson, Rebecca C; Mores, Christopher N

    2014-01-01

    Aedes aegypti has already been implicated in the emergence of dengue and chikungunya viruses in the southern US. Vector competence is the ability of a mosquito species to support transmission of an arbovirus, which is bounded by its ability to support replication and dissemination of the virus through the mosquito body to the salivary glands to be expectorated in the saliva at the time of feeding on a vertebrate host. Here, we investigate the vector competence of A. aegypti for the arbovirus koutango by orally challenging mosquitoes with two titers of virus. We calculated the effective vector competence, a cumulative measure of transmission capability weighted by mosquito survival, and determined that A. aegypti was competent at the higher dose only. We conclude that further investigation is needed to determine the infectiousness of vertebrate hosts to fully assess the emergence potential of this virus in areas rich in A. aegypti. PMID:25574140

  16. Evolution of mosquito preference for humans linked to an odorant receptor

    PubMed Central

    McBride, Carolyn S.; Baier, Felix; Omondi, Aman B.; Spitzer, Sarabeth A.; Lutomiah, Joel; Sang, Rosemary; Ignell, Rickard; Vosshall, Leslie B.

    2014-01-01

    Female mosquitoes are major vectors of human disease and the most dangerous are those that preferentially bite humans. A ‘domestic’ form of the mosquito Aedes aegypti has evolved to specialize in biting humans and is the major worldwide vector of dengue, yellow fever, and Chikungunya viruses. The domestic form coexists with an ancestral, animal-biting ‘forest’ form along the coast of Kenya. We collected the two forms, established laboratory colonies, and document striking divergence in preference for human versus animal odour. We further show that the evolution of preference for human odour in domestic mosquitoes is tightly linked to increases in the expression and ligand-sensitivity of the odorant receptor AaegOr4, which we found recognises a compound present at high levels in human odour. Our results provide a rare example of a gene contributing to behavioural evolution and provide insight into how disease-vectoring mosquitoes came to specialise on humans. PMID:25391959

  17. Bacterial Diversity Associated with Wild Caught Anopheles Mosquitoes from Dak Nong Province, Vietnam Using Culture and DNA Fingerprint

    PubMed Central

    Ngo, Chung Thuy; Aujoulat, Fabien; Veas, Francisco; Jumas-Bilak, Estelle; Manguin, Sylvie

    2015-01-01

    Background Microbiota of Anopheles midgut can modulate vector immunity and block Plasmodium development. Investigation on the bacterial biodiversity in Anopheles, and specifically on the identification of bacteria that might be used in malaria transmission blocking approaches, has been mainly conducted on malaria vectors of Africa. Vietnam is an endemic country for both malaria and Bancroftian filariasis whose parasitic agents can be transmitted by the same Anopheles species. No information on the microbiota of Anopheles mosquitoes in Vietnam was available previous to this study. Method The culture dependent approach, using different mediums, and culture independent (16S rRNA PCR – TTGE) method were used to investigate the bacterial biodiversity in the abdomen of 5 Anopheles species collected from Dak Nong Province, central-south Vietnam. Molecular methods, sequencing and phylogenetic analysis were used to characterize the microbiota. Results and Discussion The microbiota in wild-caught Anopheles was diverse with the presence of 47 bacterial OTUs belonging to 30 genera, including bacterial genera impacting Plasmodium development. The bacteria were affiliated with 4 phyla, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria, the latter being the dominant phylum. Four bacterial genera are newly described in Anopheles mosquitoes including Coxiella, Yersinia, Xanthomonas, and Knoellia. The bacterial diversity per specimen was low ranging from 1 to 4. The results show the importance of pairing culture and fingerprint methods to better screen the bacterial community in Anopheles mosquitoes. Conclusion Sampled Anopheles species from central-south Vietnam contained a diverse bacterial microbiota that needs to be investigated further in order to develop new malaria control approaches. The combination of both culture and DNA fingerprint methods allowed a thorough and complementary screening of the bacterial community in Anopheles mosquitoes. PMID:25747513

  18. Characterization of Anopheles gambiae (African Malaria Mosquito) Ferritin and the Effect of Iron on Intracellular Localization in Mosquito Cells.

    PubMed

    Geiser, Dawn L; Conley, Zachary R; Elliott, Jamie L; Mayo, Jonathan J; Winzerling, Joy J

    2015-01-01

    Ferritin is a 24-subunit molecule, made up of heavy chain (HC) and light chain (LC) subunits, which stores and controls the release of dietary iron in mammals, plants, and insects. In mosquitoes, dietary iron taken in a bloodmeal is stored inside ferritin. Our previous work has demonstrated the transport of dietary iron to the ovaries via ferritin during oogenesis. We evaluated the localization of ferritin subunits inside CCL-125 [Aedes aegypti Linnaeus (Diptera: Culicidae), yellow fever mosquito] and 4a3b [Anopheles gambiae Giles (Diptera: Culicidae), African malaria mosquito] cells under various iron treatment conditions to further elucidate the regulation of iron metabolism in these important disease vectors and to observe the dynamics of the intracellular ferritin subunits following iron administration. Deconvolution microscopy captured 3D fluorescent images of iron-treated mosquito cells to visualize the ferritin HC and LC homologue subunits (HCH and LCH, respectively) in multiple focal planes. Fluorescent probes were used to illuminate cell organelles (i.e., Golgi apparatus, lysosomes, and nuclei) while secondary probes for specific ferritin subunits demonstrated abundance and co-localization within organelles. These images will help to develop a model for the biochemical regulation of ferritin under conditions of iron exposure, and to advance novel hypotheses for the crucial role of iron in mosquito vectors. PMID:26078302

  19. Comprehensive sterilization of malaria vectors using pyriproxyfen: a step closer to malaria elimination.

    PubMed

    Lwetoijera, Dickson W; Harris, Caroline; Kiware, Samson S; Killeen, Gerry F; Dongus, Stefan; Devine, Gregor J; Majambere, Silas

    2014-05-01

    One of the main challenges to malaria elimination is the resilience of vectors, such as Anopheles arabiensis, that evade lethal exposure to insecticidal control measures or express resistance to their active ingredients. This study investigated a novel technology for population control that sterilizes mosquitoes using pyriproxyfen, a juvenile hormone analogue. Females of An. arabiensis were released in a semifield system divided into four equal sections, and each section had a mud hut sheltering a tethered cow providing a blood source for mosquitoes. In all sections, the inner mud hut walls and roofs were lined with black cotton cloth. In one-half of the sections, the cloth was dusted with pyriproxyfen. An overwhelming 96% reduction in adult production was achieved in pyriproxyfen-treated sections compared with control sections. This unprecedented level of control can be exploited to design new vector control strategies that particularly target existing behaviorally resilient and insecticide-resistant populations. PMID:24639296

  20. What does not kill them makes them stronger: larval environment and infectious dose alter mosquito potential to transmit filarial worms.

    PubMed

    Breaux, Jennifer A; Schumacher, Molly K; Juliano, Steven A

    2014-07-01

    For organisms with complex life cycles, larval environments can modify adult phenotypes. For mosquitoes and other vectors, when physiological impacts of stressors acting on larvae carry over into the adult stage they may interact with infectious dose of a vector-borne pathogen, producing a range of phenotypes for vector potential. Investigation of impacts of a common source of stress, larval crowding and intraspecific competition, on adult vector interactions with pathogens may increase our understanding of the dynamics of pathogen transmission by mosquito vectors. Using Aedes aegypti and the nematode parasite Brugia pahangi, we demonstrate dose dependency of fitness effects of B. pahangi infection on the mosquito, as well as interactions between competitive stress among larvae and infectious dose for resulting adults that affect the physiological and functional ability of mosquitoes to act as vectors. Contrary to results from studies on mosquito-arbovirus interactions, our results suggest that adults from crowded larvae may limit infection better than do adults from uncrowded controls, and that mosquitoes from high-quality larval environments are more physiologically and functionally capable vectors of B. pahangi. Our results provide another example of how the larval environment can have profound effects on vector potential of resulting adults. PMID:24827444

  1. Effect of combining mosquito repellent and insecticide treated net on malaria prevalence in Southern Ethiopia: a cluster-randomised trial

    PubMed Central

    2014-01-01

    Background A mosquito repellent has the potential to prevent malaria infection, but there has been few studies demonstrating the effectiveness of combining this strategy with the highly effective long-lasting insecticidal nets (LLINs). This study aimed to determine the effect of combining community-based mosquito repellent with LLINs in the reduction of malaria. Methods A community-based clustered-randomised trial was conducted in 16 rural villages with 1,235 households in southern Ethiopia between September and December of 2008. The villages were randomly assigned to intervention (mosquito repellent and LLINs, eight villages) and control (LLINs alone, eight villages) groups. Households in the intervention villages received mosquito repellent (i.e., Buzz-Off® petroleum jelly, essential oil blend) applied every evening. The baseline survey was followed by two follow-up surveys, at one month interval. The primary outcome was detection of Plasmodium falciparum, Plasmodium vivax, or both parasites, through microscopic examination of blood slides. Analysis was by intention to treat. Baseline imbalances and clustering at individual, household and village levels were adjusted using a generalized linear mixed model. Results 3,078 individuals in intervention and 3,004 in control group were enrolled into the study. Compared with the control arm, the combined use of mosquito repellent and LLINs significantly reduced malaria infection of all types over time [adjusted Odds Ratio (aOR)?=?0.66; 95% CI?=?0.45-0.97]. Similarly, a substantial reduction in P. falciparum malaria infection during the follow-up surveys was observed in the intervention group (aOR?=?0.53, 95% CI?=?0.31-0.89). The protective efficacy of using mosquito repellent and LLINs against malaria infection of both P. falciparum/P. vivax and P. falciparum was 34% and 47%, respectively. Conclusions Daily application of mosquito repellent during the evening followed by the use of LLINs during bedtime at community level has significantly reduced malaria infection. The finding has strong implication particularly in areas where malaria vectors feed mainly in the evening before bedtime. Trial registration ClinicalTrials.gov identifier: NCT01160809. PMID:24678612

  2. Bottlenecks and multiple introductions: Population genetics of the vector of avian malaria in Hawaii

    USGS Publications Warehouse

    Fonseca, D.M.; Lapointe, D.A.; Fleischer, R.C.

    2000-01-01

    Avian malaria has had a profound impact on the demographics and behaviour of Hawaiian forest birds since its vector, Culex quinquefasciatus the southern house mosquito, was first introduced to Hawaii around 1830. In order to understand the dynamics of the disease in Hawaii and gain insights into the evolution of vector-mediated parasite-host interactions in general we studied the population genetics of Cx. quinquefasciatus in the Hawaiian Islands. We used both microsatellite and mitochondrial loci. Not surprisingly we found that mosquitoes in Midway, a small island in the Western group, are quite distinct from the populations in the main Hawaiian Islands. However, we also found that in general mosquito populations are relatively isolated even among the main islands, in particular between Hawaii (the Big Island) and the remaining Hawaiian Islands. We found evidence of bottlenecks among populations within the Big Island and an excess of alleles in Maui, the site of the original introduction. The mitochondrial diversity was typically low but higher than expected. The current distribution of mitochondrial haplotypes combined with the microsatellite information lead us to conclude that there have been several introductions and to speculate on some processes that may be responsible for the current population genetics of vectors of avian malaria in Hawaii.

  3. DIFFERENTIAL INFECTIVITIES OF O'NYONG-NYONG AND CHIKUNGUNYA VIRUS ISOLATES IN ANOPHELES GAMBIAE AND AEDES AEGYPTI MOSQUITOES

    Microsoft Academic Search

    DANA L. VANLANDINGHAM; CHAO HONG; KIMBERLY KLINGLER; KONSTANTIN TSETSARKIN; KATE L. MCELROY; ANN M. POWERS; MICHAEL J. LEHANE; STEPHEN HIGGS

    O'nyong-nyong virus (ONNV) and chikungunya virus (CHIKV) are closely related alphaviruses that cause human disease in Africa and Asia. Like most alphaviruses, CHIKV is vectored by culicine mosquitoes. ONNV is considered unusual as it primarily infects anopheline mosquitoes; however, there are relatively few experimental data to support this. In this study, three strains of ONNV and one strain of CHIKV

  4. Mosquito Control Around the Home (Spanish)

    E-print Network

    Jackman, John A.; Olson, Jimmy K.

    2003-03-17

    This brochure explains how to reduce mosquito problems by eliminating breeding sites for larvae, controlling adult mosquitoes, avoiding contact with mosquitoes and treating larval breeding sites. Long-term control is also discussed....

  5. Mosquito Control Around the Home (Spanish) 

    E-print Network

    Jackman, John A.; Olson, Jimmy K.

    2008-08-05

    This leaflet explains how to reduce mosquito problems by eliminating breeding sites for larvae, controlling adult mosquitoes, avoiding contact with mosquitoes and treating larval breeding sites. Long-term control is also discussed....

  6. A Visit to Florida's Mosquito Man

    NSDL National Science Digital Library

    This radio broadcast features an interview with George O'Meara, the world's foremost expert on mosquitoes, who studies mosquito biology and dispenses fun facts (such as: only female mosquitoes bite). There are descriptions of the most aggressive mosquito species, how to tell female mosquitoes from males, and a discussion of landing rates of mosquitoes in the Everglades National Park. The clip is 5 minutes and 30 seconds in length.

  7. European Surveillance for West Nile Virus in Mosquito Populations

    PubMed Central

    Engler, Olivier; Savini, Giovanni; Papa, Anna; Figuerola, Jordi; Groschup, Martin H.; Kampen, Helge; Medlock, Jolyon; Vaux, Alexander; Wilson, Anthony J.; Werner, Doreen; Jöst, Hanna; Goffredo, Maria; Capelli, Gioia; Federici, Valentina; Tonolla, Mauro; Patocchi, Nicola; Flacio, Eleonora; Portmann, Jasmine; Rossi-Pedruzzi, Anya; Mourelatos, Spiros; Ruiz, Santiago; Vázquez, Ana; Calzolari, Mattia; Bonilauri, Paolo; Dottori, Michele; Schaffner, Francis; Mathis, Alexander; Johnson, Nicholas

    2013-01-01

    A wide range of arthropod-borne viruses threaten both human and animal health either through their presence in Europe or through risk of introduction. Prominent among these is West Nile virus (WNV), primarily an avian virus, which has caused multiple outbreaks associated with human and equine mortality. Endemic outbreaks of West Nile fever have been reported in Italy, Greece, France, Romania, Hungary, Russia and Spain, with further spread expected. Most outbreaks in Western Europe have been due to infection with WNV Lineage 1. In Eastern Europe WNV Lineage 2 has been responsible for human and bird mortality, particularly in Greece, which has experienced extensive outbreaks over three consecutive years. Italy has experienced co-circulation with both virus lineages. The ability to manage this threat in a cost-effective way is dependent on early detection. Targeted surveillance for pathogens within mosquito populations offers the ability to detect viruses prior to their emergence in livestock, equine species or human populations. In addition, it can establish a baseline of mosquito-borne virus activity and allow monitoring of change to this over time. Early detection offers the opportunity to raise disease awareness, initiate vector control and preventative vaccination, now available for horses, and encourage personal protection against mosquito bites. This would have major benefits through financial savings and reduction in equid morbidity/mortality. However, effective surveillance that predicts virus outbreaks is challenged by a range of factors including limited resources, variation in mosquito capture rates (too few or too many), difficulties in mosquito identification, often reliant on specialist entomologists, and the sensitive, rapid detection of viruses in mosquito pools. Surveillance for WNV and other arboviruses within mosquito populations varies between European countries in the extent and focus of the surveillance. This study reviews the current status of WNV in mosquito populations across Europe and how this is informing our understanding of virus epidemiology. Key findings such as detection of virus, presence of vector species and invasive mosquito species are summarized, and some of the difficulties encountered when applying a cost-effective surveillance programme are highlighted. PMID:24157510

  8. New Toxicants for Mosquito Control.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The search for new active ingredients for vector control involves two main approaches. The first is the screening of large numbers of experimental compounds (synthetic and natural products) using a primary high throughput screen (HTS) bioassay using Aedes aegypti larvae. Highly active compounds are...

  9. Human-to-mosquito transmission efficiency increases as malaria is controlled

    PubMed Central

    Churcher, Thomas S.; Trape, Jean-François; Cohuet, Anna

    2015-01-01

    The efficiency of malaria transmission between human and mosquito has been shown to be influenced by many factors in the laboratory, although their impact in the field and how this changes with disease endemicity are unknown. Here we estimate how human–mosquito transmission changed as malaria was controlled in Dielmo, Senegal. Mathematical models were fit to data collected between 1990 and the start of vector control in 2008. Results show that asexual parasite slide prevalence in humans has reduced from 70 to 20%, but that the proportion of infectious mosquitoes has remained roughly constant. Evidence suggests that this is due to an increase in transmission efficiency caused by a rise in gametocyte densities, although the uneven distribution of mosquito bites between hosts could also contribute. The resilience of mosquito infection to changes in endemicity will have important implications for planning disease control, and the development and deployment of transmission-reducing interventions. PMID:25597498

  10. Genome sequence of Anopheles sinensis provides insight into genetics basis of mosquito competence for malaria parasites

    PubMed Central

    2014-01-01

    Background Anopheles sinensis is an important mosquito vector of Plasmodium vivax, which is the most frequent and widely distributed cause of recurring malaria throughout Asia, and particularly in China, Korea, and Japan. Results We performed 454 next-generation sequencing and obtained a draft sequence of A. sinensis assembled into scaffolds spanning 220.8 million base pairs. Analysis of this genome sequence, we observed expansion and contraction of several immune-related gene families in anopheline relative to culicine mosquito species. These differences suggest that species-specific immune responses to Plasmodium invasion underpin the biological differences in susceptibility to Plasmodium infection that characterize these two mosquito subfamilies. Conclusions The A. sinensis genome produced in this study, provides an important resource for analyzing the genetic basis of susceptibility and resistance of mosquitoes to Plasmodium parasites research which will ultimately facilitate the design of urgently needed interventions against this debilitating mosquito-borne disease. PMID:24438588

  11. Genetic diversity of the mitochondrial cytochrome b gene in Lutzomyia spp., with special reference to Lutzomyia peruensis, a main vector of Leishmania (Viannia) peruviana in the Peruvian Andes.

    PubMed

    Yamamoto, Kento; Cáceres, Abraham G; Gomez, Eduardo A; Mimori, Tatsuyuki; Iwata, Hiroyuki; Korenaga, Masataka; Sakurai, Tatsuya; Katakura, Ken; Hashiguchi, Yoshihisa; Kato, Hirotomo

    2013-05-01

    The genetic divergence caused by genetic drift and/or selection is suggested to affect the vectorial capacity and insecticide susceptibility of sand flies, as well as other arthropods. In the present study, cytochrome b (cyt b) gene sequences were determined in 13 species circulating in Peru to establish a basis for analysis of the genetic structure, and the intraspecific genetic diversity was assessed in the Lutzomyia (Lu.) peruensis, a main vector species of Leishmania (Viannia) peruviana in Peruvian Andes. Analysis of intraspecific genetic diversity in the cyt b gene sequences from 36 Lu. peruensis identified 3 highly polymorphic sites in the middle region of the gene. Haplotype and gene network analyses were performed on the cyt b gene sequences of 130 Lu. peruensis in 9 Andean areas from 3 Departments (Ancash, Lima and La Libertad). The results showed that the populations of La Libertad were highly polymorphic and that their haplotypes were distinct from those of Ancash and Lima, where dominant haplotypes were observed, suggesting that a population bottleneck may have occurred in Ancash and Lima, but not in La Libertad. The present study indicated that the middle region of the cyt b gene is useful for the analysis of genetic structure in sand fly populations. PMID:23416127

  12. A Spatial Model of Mosquito Host-Seeking Behavior

    PubMed Central

    Cummins, Bree; Cortez, Ricardo; Foppa, Ivo M.; Walbeck, Justin; Hyman, James M.

    2012-01-01

    Mosquito host-seeking behavior and heterogeneity in host distribution are important factors in predicting the transmission dynamics of mosquito-borne infections such as dengue fever, malaria, chikungunya, and West Nile virus. We develop and analyze a new mathematical model to describe the effect of spatial heterogeneity on the contact rate between mosquito vectors and hosts. The model includes odor plumes generated by spatially distributed hosts, wind velocity, and mosquito behavior based on both the prevailing wind and the odor plume. On a spatial scale of meters and a time scale of minutes, we compare the effectiveness of different plume-finding and plume-tracking strategies that mosquitoes could use to locate a host. The results show that two different models of chemotaxis are capable of producing comparable results given appropriate parameter choices and that host finding is optimized by a strategy of flying across the wind until the odor plume is intercepted. We also assess the impact of changing the level of host aggregation on mosquito host-finding success near the end of the host-seeking flight. When clusters of hosts are more tightly associated on smaller patches, the odor plume is narrower and the biting rate per host is decreased. For two host groups of unequal number but equal spatial density, the biting rate per host is lower in the group with more individuals, indicative of an attack abatement effect of host aggregation. We discuss how this approach could assist parameter choices in compartmental models that do not explicitly model the spatial arrangement of individuals and how the model could address larger spatial scales and other probability models for mosquito behavior, such as Lévy distributions. PMID:22615546

  13. Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

    PubMed Central

    2014-01-01

    Background When rhesus monkeys (Macaca mulatta) are used to test malaria vaccines, animals are often challenged by the intravenous injection of sporozoites. However, natural exposure to malaria comes via mosquito bite, and antibodies can neutralize sporozoites as they traverse the skin. Thus, intravenous injection may not fairly assess humoral immunity from anti-sporozoite malaria vaccines. To better assess malaria vaccines in rhesus, a method to challenge large numbers of monkeys by mosquito bite was developed. Methods Several species and strains of mosquitoes were tested for their ability to produce Plasmodium knowlesi sporozoites. Donor monkey parasitaemia effects on oocyst and sporozoite numbers and mosquito mortality were documented. Methylparaben added to mosquito feed was tested to improve mosquito survival. To determine the number of bites needed to infect a monkey, animals were exposed to various numbers of P. knowlesi-infected mosquitoes. Finally, P. knowlesi-infected mosquitoes were used to challenge 17 monkeys in a malaria vaccine trial, and the effect of number of infectious bites on monkey parasitaemia was documented. Results Anopheles dirus, Anopheles crascens, and Anopheles dirus X (a cross between the two species) produced large numbers of P. knowlesi sporozoites. Mosquito survival to day 14, when sporozoites fill the salivary glands, averaged only 32% when donor monkeys had a parasitaemia above 2%. However, when donor monkey parasitaemia was below 2%, mosquitoes survived twice as well and contained ample sporozoites in their salivary glands. Adding methylparaben to sugar solutions did not improve survival of infected mosquitoes. Plasmodium knowlesi was very infectious, with all monkeys developing blood stage infections if one or more infected mosquitoes successfully fed. There was also a dose-response, with monkeys that received higher numbers of infected mosquito bites developing malaria sooner. Conclusions Anopheles dirus, An. crascens and a cross between these two species all were excellent vectors for P. knowlesi. High donor monkey parasitaemia was associated with poor mosquito survival. A single infected mosquito bite is likely sufficient to infect a monkey with P. knowlesi. It is possible to efficiently challenge large groups of monkeys by mosquito bite, which will be useful for P. knowlesi vaccine studies. PMID:24893777

  14. THE EFFICACY OF DIFFERENT MOSQUITO TRAPPING METHODS IN A FOREST-FRINGE VILLAGE, YUNNAN PROVINCE, SOUTHERN CHINA

    Microsoft Academic Search

    SJ Moore; Du Zunwei; Zhou Hongning; Wang Xuezhong; Li Hongbing; Xiao Yujiang; N Hill

    2001-01-01

    Despite a control program, malaria incidence in Yunnan has increased and knowledge of vector bionomics is needed for efficient control. Multi-drug resistant Plasmodium falciparum necessitates alternatives to human landing catches as a means of studying vectors. Therefore CDC light traps with UV or ordinary incandescent bulbs were tested for 57 trap nights. 2,703 mosquitos were caught, including the vector species

  15. Temporal Coordination of Carbohydrate Metabolism during Mosquito Reproduction

    PubMed Central

    Roy, Sourav; Zhao, Bo; Raikhel, Alexander S.; Zou, Zhen

    2015-01-01

    Hematophagous mosquitoes serve as vectors of multiple devastating human diseases, and many unique physiological features contribute to the incredible evolutionary success of these insects. These functions place high-energy demands on a reproducing female mosquito, and carbohydrate metabolism (CM) must be synchronized with these needs. Functional analysis of metabolic gene profiling showed that major CM pathways, including glycolysis, glycogen and sugar metabolism, and citrate cycle, are dramatically repressed at post eclosion (PE) stage in mosquito fat body followed by a sharply increase at post-blood meal (PBM) stage, which were also verified by Real-time RT-PCR. Consistent to the change of transcript and protein level of CM genes, the level of glycogen, glucose and trehalose and other secondary metabolites are also periodically accumulated and degraded during the reproductive cycle respectively. Levels of triacylglycerols (TAG), which represent another important energy storage form in the mosquito fat body, followed a similar tendency. On the other hand, ATP, which is generated by catabolism of these secondary metabolites, showed an opposite trend. Additionally, we used RNA interference studies for the juvenile hormone and ecdysone receptors, Met and EcR, coupled with transcriptomics and metabolomics analyses to show that these hormone receptors function as major regulatory switches coordinating CM with the differing energy requirements of the female mosquito throughout its reproductive cycle. Our study demonstrates how, by metabolic reprogramming, a multicellular organism adapts to drastic and rapid functional changes. PMID:26158648

  16. Temporal Coordination of Carbohydrate Metabolism during Mosquito Reproduction.

    PubMed

    Hou, Yuan; Wang, Xue-Li; Saha, Tusar T; Roy, Sourav; Zhao, Bo; Raikhel, Alexander S; Zou, Zhen

    2015-07-01

    Hematophagous mosquitoes serve as vectors of multiple devastating human diseases, and many unique physiological features contribute to the incredible evolutionary success of these insects. These functions place high-energy demands on a reproducing female mosquito, and carbohydrate metabolism (CM) must be synchronized with these needs. Functional analysis of metabolic gene profiling showed that major CM pathways, including glycolysis, glycogen and sugar metabolism, and citrate cycle, are dramatically repressed at post eclosion (PE) stage in mosquito fat body followed by a sharply increase at post-blood meal (PBM) stage, which were also verified by Real-time RT-PCR. Consistent to the change of transcript and protein level of CM genes, the level of glycogen, glucose and trehalose and other secondary metabolites are also periodically accumulated and degraded during the reproductive cycle respectively. Levels of triacylglycerols (TAG), which represent another important energy storage form in the mosquito fat body, followed a similar tendency. On the other hand, ATP, which is generated by catabolism of these secondary metabolites, showed an opposite trend. Additionally, we used RNA interference studies for the juvenile hormone and ecdysone receptors, Met and EcR, coupled with transcriptomics and metabolomics analyses to show that these hormone receptors function as major regulatory switches coordinating CM with the differing energy requirements of the female mosquito throughout its reproductive cycle. Our study demonstrates how, by metabolic reprogramming, a multicellular organism adapts to drastic and rapid functional changes. PMID:26158648

  17. Antibiotics in ingested human blood affect the mosquito microbiota and capacity to transmit malaria.

    PubMed

    Gendrin, Mathilde; Rodgers, Faye H; Yerbanga, Rakiswendé S; Ouédraogo, Jean Bosco; Basáñez, María-Gloria; Cohuet, Anna; Christophides, George K

    2015-01-01

    Malaria reduction is most efficiently achieved by vector control whereby human populations at high risk of contracting and transmitting the disease are protected from mosquito bites. Here, we identify the presence of antibiotics in the blood of malaria-infected people as a new risk of increasing disease transmission. We show that antibiotics in ingested blood enhance the susceptibility of Anopheles gambiae mosquitoes to malaria infection by disturbing their gut microbiota. This effect is confirmed in a semi-natural setting by feeding mosquitoes with blood of children naturally infected with Plasmodium falciparum. Antibiotic exposure additionally increases mosquito survival and fecundity, which are known to augment vectorial capacity. These findings suggest that malaria transmission may be exacerbated in areas of high antibiotic usage, and that regions targeted by mass drug administration programs against communicable diseases may necessitate increased vector control. PMID:25562286

  18. Antibiotics in ingested human blood affect the mosquito microbiota and capacity to transmit malaria

    PubMed Central

    Gendrin, Mathilde; Rodgers, Faye H.; Yerbanga, Rakiswendé S.; Ouédraogo, Jean Bosco; Basáñez, María-Gloria; Cohuet, Anna; Christophides, George K.

    2015-01-01

    Malaria reduction is most efficiently achieved by vector control whereby human populations at high risk of contracting and transmitting the disease are protected from mosquito bites. Here, we identify the presence of antibiotics in the blood of malaria-infected people as a new risk of increasing disease transmission. We show that antibiotics in ingested blood enhance the susceptibility of Anopheles gambiae mosquitoes to malaria infection by disturbing their gut microbiota. This effect is confirmed in a semi-natural setting by feeding mosquitoes with blood of children naturally infected with Plasmodium falciparum. Antibiotic exposure additionally increases mosquito survival and fecundity, which are known to augment vectorial capacity. These findings suggest that malaria transmission may be exacerbated in areas of high antibiotic usage, and that regions targeted by mass drug administration programs against communicable diseases may necessitate increased vector control. PMID:25562286

  19. DECEMBER,, 1969 MOSQUITO NEWS 563 M. Parrish, Louis M. Roth, Denis R-

    E-print Network

    ., and MENGIES, G. C. 1956. Texas mosquito problems from a species standpoint. Mosq. News i6(3):i87. MVKI.KBUST, R. ]., and HARMSTON, F. C. 1962. Mosquito production in stabilization ponds. Water ['ollut. ConL Fed. ). 34(3):302. RAI'P, W. F., JR. 1060. Sewage lagoon main- tenance. Water Pollut. Cent. Fed. J. 32(6) ;66

  20. Susceptibility of Anopheles stephensi to Plasmodium gallinaceum: A Trait of the Mosquito, the Parasite, and the Environment

    PubMed Central

    Hume, Jen C. C.; Hamilton, Howard; Lee, Kevin L.; Lehmann, Tovi

    2011-01-01

    Background Vector susceptibility to Plasmodium infection is treated primarily as a vector trait, although it is a composite trait expressing the joint occurrence of the parasite and the vector with genetic contributions of both. A comprehensive approach to assess the specific contribution of genetic and environmental variation on “vector susceptibility” is lacking. Here we developed and implemented a simple scheme to assess the specific contributions of the vector, the parasite, and the environment to “vector susceptibility.” To the best of our knowledge this is the first study that employs such an approach. Methodology/Principal Findings We conducted selection experiments on the vector (while holding the parasite “constant”) and on the parasite (while holding the vector “constant”) to estimate the genetic contributions of the mosquito and the parasite to the susceptibility of Anopheles stephensi to Plasmodium gallinaceum. We separately estimated the realized heritability of (i) susceptibility to parasite infection by the mosquito vector and (ii) parasite compatibility (transmissibility) with the vector while controlling the other. The heritabilities of vector and the parasite were higher for the prevalence, i.e., fraction of infected mosquitoes, than the corresponding heritabilities of parasite load, i.e., the number of oocysts per mosquito. Conclusions The vector's genetics (heritability) comprised 67% of “vector susceptibility” measured by the prevalence of mosquitoes infected with P. gallinaceum oocysts, whereas the specific contribution of parasite genetics (heritability) to this trait was only 5%. Our parasite source might possess minimal genetic diversity, which could explain its low heritability (and the high value of the vector). Notably, the environment contributed 28%. These estimates are relevant only to the particular system under study, but this experimental design could be useful for other parasite-host systems. The prospects and limitations of the genetic manipulation of vector populations to render the vector resistant to the parasite are better considered on the basis of this framework. PMID:21694762

  1. Analysis of the metabolome of Anopheles gambiae mosquito after exposure to Mycobacterium ulcerans

    PubMed Central

    Hoxmeier, J. Charles; Thompson, Brice D.; Broeckling, Corey D.; Small, Pamela; Foy, Brian D.; Prenni, Jessica; Dobos, Karen M.

    2015-01-01

    Infection with Mycobacterium ulcerans causes Buruli Ulcer, a neglected tropical disease. Mosquito vectors are suspected to participate in the transmission and environmental maintenance of the bacterium. However, mechanisms and consequences of mosquito contamination by M. ulcerans are not well understood. We evaluated the metabolome of the Anopheles gambiae mosquito to profile the metabolic changes associated with bacterial colonization. Contamination of mosquitoes with live M. ulcerans bacilli results in disruptions to lipid metabolic pathways of the mosquito, specifically the utilization of glycerolipid molecules, an affect that was not observed in mosquitoes exposed to dead M. ulcerans. These results are consistent with aberrations of lipid metabolism described in other mycobacterial infections, implying global host-pathogen interactions shared across diverse saprophytic and pathogenic mycobacterial species. This study implicates features of the bacterium, such as the putative M. ulcerans encoded phospholipase enzyme, which promote virulence, survival, and active adaptation in concert with mosquito development, and provides significant groundwork for enhanced studies of the vector-pathogen interactions using metabolomics profiling. Lastly, metabolic and survival data suggest an interaction which is unlikely to contribute to transmission of M. ulcerans by A. gambiae and more likely to contribute to persistence of M. ulcerans in waters cohabitated by both organisms. PMID:25784490

  2. Understanding the DNA damage response in order to achieve desired gene editing outcomes in mosquitoes.

    PubMed

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

    2015-02-01

    Mosquitoes are high-impact disease vectors with the capacity to transmit pathogenic agents that cause diseases such as malaria, yellow fever, chikungunya, and dengue. Continued growth in knowledge of genetic, molecular, and physiological pathways in mosquitoes allows for the development of novel control methods and for the continued optimization of existing ones. The emergence of site-specific nucleases as genomic engineering tools promises to expedite research of crucial biological pathways in these disease vectors. The utilization of these nucleases in a more precise and efficient manner is dependent upon knowledge and manipulation of the DNA repair pathways utilized by the mosquito. While progress has been made in deciphering DNA repair pathways in some model systems, research into the nature of the hierarchy of mosquito DNA repair pathways, as well as in mechanistic differences that may exist, is needed. In this review, we will describe progress in the use of site-specific nucleases in mosquitoes, along with the hierarchy of DNA repair in the context of mosquito chromosomal organization and structure, and how this knowledge may be manipulated to achieve precise chromosomal engineering in mosquitoes. PMID:25596822

  3. Susceptibility of mosquito and tick cell lines to infection with various flaviviruses.

    PubMed

    Lawrie, C H; Uzcátegui, N Y; Armesto, M; Bell-Sakyi, L; Gould, E A

    2004-09-01

    The genus Flavivirus consists of more than 70 virus species and subtypes, the majority of which are transmitted by mosquitoes or ticks, although some have no known vector (NKV). The ability of these viruses to infect cultured cells derived from mosquito or tick species offers a useful insight into the suitability of such vectors to harbour and replicate particular viruses. We undertook a comparative study of the susceptibility of mammalian Vero cells, a clonal mosquito cell line (C6/36) and recently developed cell lines derived from the ticks (Acari: Ixodidae) Ixodes ricinus (L.) (IRE/CTVM18), I. scapularis (Say) (ISE6), Rhipicephalus appendiculatus (Neumann) (RAE/CTVM1) and Amblyomma variegatum (Fabricius) (AVL/CTVM17) to infection with 13 flaviviruses (and one alphavirus) using immunofluorescence microscopy and plaque assay techniques. The C6/36 mosquito cell line was infected by all the mosquito-borne flaviviruses tested but not by NKV viruses or tick-borne viruses, with the exception of Langat virus (LGTV). The tick cell lines were susceptible to infection by all of the tick-borne viruses tested, as well as two mosquito-borne viruses, West Nile virus (WNV) and the alphavirus, Venezuelan equine encephalitis virus (VEEV), but not other mosquito-borne viruses or NKV viruses. PMID:15347394

  4. Controlling malaria transmission with genetically-engineered, Plasmodium-resistant mosquitoes: milestones in a model system.

    PubMed

    James, A A; Beerntsen, B T; Capurro, M de L; Coates, C J; Coleman, J; Jasinskiene, N; Krettli, A U

    1999-09-01

    We are developing transgenic mosquitoes resistant to malaria parasites to test the hypothesis that genetically-engineered mosquitoes can be used to block the transmission of the parasites. We are developing and testing many of the necessary methodologies with the avian malaria parasite, Plasmodium gallinaceum, and its laboratory vector, Aedes aegypti, in anticipation of engaging the technical challenges presented by the malaria parasite, P. falciparum, and its major African vector, Anopheles gambiae. Transformation technology will be used to insert into the mosquito a synthetic gene for resistance to P. gallinaceum. The resistance gene will consist of a promoter of a mosquito gene controlling the expression of an effector protein that interferes with parasite development and/or infectivity. Mosquito genes whose promoter sequences are capable of sex- and tissue-specific expression of exogenous coding sequences have been identified, and stable transformation of the mosquito has been developed. We now are developing the expressed effector portion of the synthetic gene that will interfere with the transmission of the parasites. Mouse monoclonal antibodies that recognize the circumsporozoite protein of P. gallinaceum block sporozoite invasion of mosquito salivary glands, as well as abrogate the infectivity of sporozoites to a vertebrate host, the chicken, Gallus gallus, and block sporozoite invasion and development in susceptible cell lines in vitro. Using the genes encoding these antibodies, we propose to clone and express single-chain antibody constructs (scFv) that will serve as the effector portion of the gene that interferes with transmission of P. gallinaceum sporozoites. PMID:10697903

  5. Host Selection by Culex pipiens Mosquitoes and West Nile Virus Amplification

    Microsoft Academic Search

    Gabriel L. Hamer; Uriel D. Kitron; Tony L. Goldberg; Jeffrey D. Brawn; Scott R. Loss; Marilyn O. Ruiz; Daniel B. Hayes; Edward D. Walker

    Abstract. , Recent field studies have suggested,that the dynamics,of West Nile virus (WNV) transmission,are influenced strongly by a,few key super spreader,bird species that function both as primary,blood hosts of the,vector mosquitoes (in particular Culex pipiens ) and as reservoir-competent,virus hosts. It has been,hypothesized,that human,cases result from a shift in mosquito feeding from these key bird species to humans after abundance,of

  6. Species Composition of Bacterial Communities Influences Attraction of Mosquitoes to Experimental Plant Infusions

    Microsoft Academic Search

    Loganathan Ponnusamy; Dawn M. Wesson; Consuelo Arellano; Coby Schal; Charles S. Apperson

    2010-01-01

    In the container habitats of immature mosquitoes, catabolism of plant matter and other organic detritus by microbial organisms\\u000a produces metabolites that mediate the oviposition behavior of Aedes aegypti and Aedes albopictus. Public health agencies commonly use oviposition traps containing plant infusions for monitoring populations of these mosquito\\u000a species, which are global vectors of dengue viruses. In laboratory experiments, gravid females

  7. Implication of the Mosquito Midgut Microbiota in the Defense against Malaria Parasites

    PubMed Central

    Dong, Yuemei; Manfredini, Fabio; Dimopoulos, George

    2009-01-01

    Malaria-transmitting mosquitoes are continuously exposed to microbes, including their midgut microbiota. This naturally acquired microbial flora can modulate the mosquito's vectorial capacity by inhibiting the development of Plasmodium and other human pathogens through an unknown mechanism. We have undertaken a comprehensive functional genomic approach to elucidate the molecular interplay between the bacterial co-infection and the development of the human malaria parasite Plasmodium falciparum in its natural vector Anopheles gambiae. Global transcription profiling of septic and aseptic mosquitoes identified a significant subset of immune genes that were mostly up-regulated by the mosquito's microbial flora, including several anti-Plasmodium factors. Microbe-free aseptic mosquitoes displayed an increased susceptibility to Plasmodium infection while co-feeding mosquitoes with bacteria and P. falciparum gametocytes resulted in lower than normal infection levels. Infection analyses suggest the bacteria-mediated anti-Plasmodium effect is mediated by the mosquitoes' antimicrobial immune responses, plausibly through activation of basal immunity. We show that the microbiota can modulate the anti-Plasmodium effects of some immune genes. In sum, the microbiota plays an essential role in modulating the mosquito's capacity to sustain Plasmodium infection. PMID:19424427

  8. GIS Early-Warning System for Vectors of Rift Valley Fever: Anomaly Analysis of Climate-Population Associations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A critical component of predicting the risk of transmission of mosquito-borne viruses is knowing the status of vector populations. Mosquito control agencies have good systems for measuring mosquito populations at county or district levels, but these data are not synthesized to regional or national ...

  9. Gene expression divergence between malaria vector sibling species Anopheles gambiae and An. coluzzii from

    E-print Network

    Hahn, Matthew

    Gene expression divergence between malaria vector sibling species Anopheles gambiae and An identical African mosquito spe- cies, the malaria vectors Anopheles gambiae and An. coluzzii. Population. Functional enrichment analysis of differentially expressed genes revealed that An. coluzzii ­ the species

  10. The Ultimate Buzz Kill Mosquito Control

    E-print Network

    Johnson, Eric E.

    : egg, larva, pupa, and adult. 2. Mosquitoes lay groups of eggs on the surface of water or at the base larvae. Unused swimming pools should be drained and kept dry during the mosquito season. Larval ControlThe Ultimate Buzz Kill Mosquito Control Biology Lesson 1. All mosquitoes pass through 4 life stages

  11. Wolbachia-based population control strategy targeting Culex quinquefasciatus mosquitoes proves efficient under semi-field conditions.

    PubMed

    Atyame, Célestine M; Cattel, Julien; Lebon, Cyrille; Flores, Olivier; Dehecq, Jean-Sébastien; Weill, Mylène; Gouagna, Louis Clément; Tortosa, Pablo

    2015-01-01

    In mosquitoes, the maternally inherited bacterial Wolbachia induce a form of embryonic lethality called cytoplasmic incompatibility (CI). This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy). We have previously constructed the LR[wPip(Is)] line representing a good candidate for controlling field populations of the Culex quinquefasciatus mosquito in the islands of the south-western Indian Ocean. The main purpose of the present study was to fill the gap between laboratory experiments and field implementation, i.e. assessing mating competitiveness of these incompatible males under semi-field conditions. In a first set of experiments, we analyzed crossing relationships between LR[wPip(Is)] males and La Réunion field females collected as larvae in 19 distinct localities throughout the island. This investigation revealed total embryonic mortality, confirming the strong sterilizing capacity of LR[wPip(Is)] males. Subsequently, mating competitiveness of LR[wPip(Is)] males was assessed under semi-field conditions in the presence of field males and females from La Réunion. Confrontations were carried out in April and December using different ratios of LR[wPip(Is)] to field males. The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April. Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens. PMID:25768841

  12. Molecular Identification of Vertebrate and Hemoparasite DNA Within Mosquito Blood Meals From Eastern North Dakota

    PubMed Central

    Vaughan, Jefferson A.

    2013-01-01

    Abstract To understand local transmission of vector-borne diseases, it is important to identify potential vectors, characterize their host feeding patterns, and determine if vector-borne pathogens are circulating within the region. This study simultaneously investigated these aspects of disease transmission by collecting engorged mosquitoes within two rural study sites in the central Red River Valley of North Dakota. Mosquitoes were identified, midguts were excised, and the blood was expelled from the midguts. DNA was extracted from blood meals and subjected to PCR and direct sequencing to identify the vertebrate origin of the blood. Using different primer sets, PCR was used to screen for two types of vector-borne pathogens, filarioid nematodes and hemosporidian parasites. White-tailed deer were the primary source of blood meals for the eight aedine mosquito species collected. None of the 288 deer-derived blood meals contained filarioid or hemosporidian DNA. In contrast, 18 of 32 Culex tarsalis and three of three Cx. pipiens blood meals contained avian blood, representing eight different species of birds. Of 24 avian-derived blood meals examined, 12 contained Plasmodium DNA, three of which also contained Leucocytozoon DNA (i.e., dual infection). Potential confounding effects resulting from parasite acquisition and development from previous blood meals (e.g., oocysts) were eliminated because host blood had been removed from the midguts prior to DNA extraction. Thus, specific parasite lineages/species could be unequivocally linked to specific vertebrate species. By combining mosquito identification with molecular techniques for identifying blood meal source and pathogens, a relatively small sample of engorged mosquitoes yielded important new information about mosquito feeding patterns and hemosporidia infections in birds. Thorough analyses of wild-caught engorged mosquitoes and other arthropods represent a powerful tool in understanding the local transmission of vector-borne and zoonotic diseases. PMID:24107213

  13. Statistical Modeling of the Abundance of Vectors of West African Rift Valley Fever in Barkédji, Senegal

    PubMed Central

    Talla, Cheikh; Diallo, Diawo; Dia, Ibrahima; Ba, Yamar; Ndione, Jacques-André; Sall, Amadou Alpha; Morse, Andy; Diop, Aliou; Diallo, Mawlouth

    2014-01-01

    Rift Valley fever is an emerging mosquito-borne disease that represents a threat to human and animal health. The exophilic and exophagic behavior of the two main vector in West Africa (Aedes vexans and Culex poicilipes), adverse events post-vaccination, and lack of treatment, render ineffective the disease control. Therefore it is essential to develop an information system that facilitates decision-making and the implementation of adaptation strategies. In East Africa, RVF outbreaks are linked with abnormally high rainfall, and can be predicted up to 5 months in advance by modeling approaches using climatic and environmental parameters. However, the application of these models in West Africa remains unsatisfactory due to a lack of data for animal and human cases and differences in the dynamics of the disease emergence and the vector species involved in transmission. Models have been proposed for West Africa but they were restricted to rainfall impact analysis without a spatial dimension. In this study, we developed a mixed Bayesian statistical model to evaluate the effects of climatic and ecological determinants on the spatiotemporal dynamics of the two main vectors. Adult mosquito abundance data were generated from July to December every fortnight in 2005–2006 at 79 sites, including temporary ponds, bare soils, shrubby savannah, wooded savannah, steppes, and villages in the Barkédji area. The results demonstrate the importance of environmental factors and weather conditions for predicting mosquito abundance. The rainfall and minimum temperature were positively correlated with the abundance of Cx. poicilipes, whereas the maximum temperature had negative effects. The rainfall was negatively correlated with the abundance of Ae. vexans. After combining land cover classes, weather conditions, and vector abundance, our model was used to predict the areas and periods with the highest risks of vector pressure. This information could support decision-making to improve RVF surveillance activities and to implement better intervention strategies. PMID:25437856

  14. Isolongifolenone: A Novel Sesquiterpene Repellent of Ticks and Mosquitoes

    Microsoft Academic Search

    Aijun Zhang; Jerome A. Klun; Shifa Wang; John F. Carroll; Mustapha Debboun

    2009-01-01

    A naturally occurring sesquiterpene, isolongifolenone, derivatives of which have been used extensively as ingredients in the cosmetics industry, was discovered to effectively repel blood- feeding arthropods that are important disease vectors. We show that (Ð)-isolongifolenone deters the biting of the mosquitoes, Aedes aegypti (L.) and Anopheles stephensi Liston, more effectively than the widely used synthetic chemical repellent, N,N-diethyl-3-methyl benzamide (DEET),

  15. Insect Vectors of Disease

    NSDL National Science Digital Library

    0000-00-00

    A Cornell University page including a PDF file of a Power Point lecture dealing with medical entomology. This lecture mainly details the importance of mosquitoes and lice, covering historical and well as current health issues, morphology, and life history. Links to many other to entomology topics are included on the page.

  16. Immunization of Mice with Recombinant Mosquito Salivary Protein D7 Enhances Mortality from Subsequent West Nile Virus Infection via Mosquito Bite

    PubMed Central

    Reagan, Krystle L.; Machain-Williams, Carlos; Wang, Tian; Blair, Carol D.

    2012-01-01

    Background Mosquito salivary proteins (MSPs) modulate the host immune response, leading to enhancement of arboviral infections. Identification of proteins in saliva responsible for immunomodulation and counteracting their effects on host immune response is a potential strategy to protect against arboviral disease. We selected a member of the D7 protein family, which are among the most abundant and immunogenic in mosquito saliva, as a vaccine candidate with the aim of neutralizing effects on the mammalian immune response normally elicited by mosquito saliva components during arbovirus transmission. Methodology/Principal Findings We identified D7 salivary proteins of Culex tarsalis, a West Nile virus (WNV) vector in North America, and expressed 36 kDa recombinant D7 (rD7) protein for use as a vaccine. Vaccinated mice exhibited enhanced interferon-? and decreased interleukin-10 expression after uninfected mosquito bite; however, we found unexpectedly that rD7 vaccination resulted in enhanced pathogenesis from mosquito-transmitted WNV infection. Passive transfer of vaccinated mice sera to naïve mice also resulted in increased mortality rates from subsequent mosquito-transmitted WNV infection, implicating the humoral immune response to the vaccine in enhancement of viral pathogenesis. Vaccinated mice showed decreases in interferon-? and increases in splenocytes producing the regulatory cytokine IL-10 after WNV infection by mosquito bite. Conclusions/Significance Vector saliva vaccines have successfully protected against other blood-feeding arthropod-transmitted diseases. Nevertheless, the rD7 salivary protein vaccine was not a good candidate for protection against WNV disease since immunized mice infected via an infected mosquito bite exhibited enhanced mortality. Selection of salivary protein vaccines on the bases of abundance and immunogenicity does not predict efficacy. PMID:23236530

  17. Landscape Effects on the Presence, Abundance and Diversity of Mosquitoes in Mediterranean Wetlands.

    PubMed

    Roiz, David; Ruiz, Santiago; Soriguer, Ramon; Figuerola, Jordi

    2015-01-01

    Environment determines the distribution of mosquito-borne diseases in that it influences the vector-host-pathogen transmission cycle, including vector distribution, abundance and diversity. In this study, we analyse the relationship between environmental variables estimated by remote sensing and the spatial distribution (presence, abundance and diversity) of seven mosquito species vectors of West Nile and other pathogens (Usutu, avian malaria and dirofilariasis) in the Doñana Natural Park, Spain. Traps were distributed over an area of 54,984 ha divided into six ecological units: marshland, sand dunes, scrubland, ricefields, crops and fishponds. We collected mosquitoes once a month from up to 112 locations using BG-Sentinel traps baited with BG-lure and CO2 during March-November 2010. Hydroperiod, NDVI and Inundation surface were estimated at several resolution scales (100, 250, 500, 1000 and 2000 metres) from corrected and normalized Landsat Images. We sampled 972,346 female mosquitoes, the most abundant species being Culex theileri, Ochlerotatus caspius, Culex modestus, Culex perexiguus, Culex pipiens, Anopheles atroparvus and Ochlerotatus detritus. Our results suggest that: (1) hydroperiod, inundation surface and NDVI are strongly related to the spatial distribution of mosquitoes; (2) the spatial scales used to measure these variables affected quantification of these relationships, the larger scale being more informative; (3) these relationships are species-specific; (4) hydroperiod is negatively related to mosquito presence and richness; (5) Culex abundance is positively related to hydroperiod; (6) NDVI is positively related to mosquito diversity, presence and abundance, except in the case of the two salt marsh species (Oc. caspius and Oc. detritus); and (7) inundation surfaces positively condition the abundance and richness of most species except the salt marsh mosquitoes. Remote sensing data provided reliable information for monitoring mosquito populations. Landscape significantly affected mosquito distribution and abundance, and as a result may alter disease risk. These results suggest that while environmental conditions affect the distribution and abundance of mosquitoes, other factors such as human modification of landscapes may give rise to significant changes in mosquito populations and consequently disease risk. PMID:26086804

  18. Landscape Effects on the Presence, Abundance and Diversity of Mosquitoes in Mediterranean Wetlands

    PubMed Central

    Roiz, David; Ruiz, Santiago; Soriguer, Ramon; Figuerola, Jordi

    2015-01-01

    Environment determines the distribution of mosquito-borne diseases in that it influences the vector-host-pathogen transmission cycle, including vector distribution, abundance and diversity. In this study, we analyse the relationship between environmental variables estimated by remote sensing and the spatial distribution (presence, abundance and diversity) of seven mosquito species vectors of West Nile and other pathogens (Usutu, avian malaria and dirofilariasis) in the Doñana Natural Park, Spain. Traps were distributed over an area of 54,984 ha divided into six ecological units: marshland, sand dunes, scrubland, ricefields, crops and fishponds. We collected mosquitoes once a month from up to 112 locations using BG-Sentinel traps baited with BG-lure and CO2 during March-November 2010. Hydroperiod, NDVI and Inundation surface were estimated at several resolution scales (100, 250, 500, 1000 and 2000 metres) from corrected and normalized Landsat Images. We sampled 972,346 female mosquitoes, the most abundant species being Culex theileri, Ochlerotatus caspius, Culex modestus, Culex perexiguus, Culex pipiens, Anopheles atroparvus and Ochlerotatus detritus. Our results suggest that: (1) hydroperiod, inundation surface and NDVI are strongly related to the spatial distribution of mosquitoes; (2) the spatial scales used to measure these variables affected quantification of these relationships, the larger scale being more informative; (3) these relationships are species-specific; (4) hydroperiod is negatively related to mosquito presence and richness; (5) Culex abundance is positively related to hydroperiod; (6) NDVI is positively related to mosquito diversity, presence and abundance, except in the case of the two salt marsh species (Oc. caspius and Oc. detritus); and (7) inundation surfaces positively condition the abundance and richness of most species except the salt marsh mosquitoes. Remote sensing data provided reliable information for monitoring mosquito populations. Landscape significantly affected mosquito distribution and abundance, and as a result may alter disease risk. These results suggest that while environmental conditions affect the distribution and abundance of mosquitoes, other factors such as human modification of landscapes may give rise to significant changes in mosquito populations and consequently disease risk. PMID:26086804

  19. Do Topical Repellents Divert Mosquitoes within a Community? – Health Equity Implications of Topical Repellents as a Mosquito Bite Prevention Tool

    PubMed Central

    Maia, Marta Ferreira; Onyango, Sangoro Peter; Thele, Max; Simfukwe, Emmanuel Titus; Turner, Elizabeth Louise; Moore, Sarah Jane

    2013-01-01

    Objectives Repellents do not kill mosquitoes - they simply reduce human-vector contact. Thus it is possible that individuals who do not use repellents but dwell close to repellent users experience more bites than otherwise. The objective of this study was to measure if diversion occurs from households that use repellents to those that do not use repellents. Methods The study was performed in three Tanzanian villages using 15%-DEET and placebo lotions. All households were given LLINs. Three coverage scenarios were investigated: complete coverage (all households were given 15%-DEET), incomplete coverage (80% of households were given 15%-DEET and 20% placebo) and no coverage (all households were given placebo). A crossover study design was used and coverage scenarios were rotated weekly over a period of ten weeks. The placebo lotion was randomly allocated to households in the incomplete coverage scenario. The level of compliance was reported to be close to 100%. Mosquito densities were measured through aspiration of resting mosquitoes. Data were analysed using negative binomial regression models. Findings Repellent-users had consistently fewer mosquitoes in their dwellings. In villages where everybody had been given 15%-DEET, resting mosquito densities were fewer than half that of households in the no coverage scenario (Incidence Rate Ratio [IRR]=0.39 (95% confidence interval [CI]: 0.25-0.60); p<0.001). Placebo-users living in a village where 80% of the households used 15%-DEET were likely to have over four-times more mosquitoes (IRR=4.17; 95% CI: 3.08-5.65; p<0.001) resting in their dwellings in comparison to households in a village where nobody uses repellent. Conclusions There is evidence that high coverage of repellent use could significantly reduce man-vector contact but with incomplete coverage evidence suggests that mosquitoes are diverted from households that use repellent to those that do not. Therefore, if repellents are to be considered for vector control, strategies to maximise coverage are required. PMID:24376852

  20. [Vector transmitted diseases and climate changes in Europe].

    PubMed

    Rossati, Antonella; Bargiacchi, Olivia; Kroumova, Vesselina; Garavelli, Pietro Luigi

    2014-09-01

    The increase in temperatures recorded since the mid-nineteenth century is unprecedented in the history of mankind. The consequences of climate changes are numerous and can affect human health through direct (extreme events, natural disasters) or indirect (alteration of the ecosystem) mechanisms. Climate changes have repercussions on ecosystems, agriculture, social conditions, migration, conflicts and the transmission mode of infectious diseases. Vector-borne diseases are infections transmitted by the bite of infected arthropods such as mosquitoes, ticks, triatomines, sand flies and flies. Epidemiological cornerstones of vector-borne diseases are: the ecology and behaviour of the host, the ecology and behaviour of the vector, and the population's degree of immunity. Mosquito vectors related to human diseases mainly belong to the genus Culex, Aedes and Mansonia. Climate changes in Europe have increased the spread of new vectors, such as Aedes albopictus, and in some situations have made it possible to sustain the autochthonous transmission of some diseases (outbreak of Chukungunya virus in northern Italy in 2007, cases of dengue in the South of France and in Croatia). Despite the eradication of malaria from Europe, anopheline carriers are still present, and they may allow the transmission of the disease if the climatic conditions favour the development of the vectors and their contacts with plasmodium carriers. The tick Ixodes ricinus is a vector whose expansion has been documented both in latitude and in altitude in relation to the temperature increase; at the same time the related main viral and bacterial infections have increased. In northern Italy and Germany, the appearance of Leishmaniasis has been associated to climatic conditions that favour the development of the vector Phlebotomus papatasi and the maturation of the parasite within the vector, although the increase of cases of visceral leishmaniasis is also related to host immune factors, particularly immunodepression caused by the human immunodeficiency virus (HIV). Despite the importance of global warming in facilitating the transmission of certain infectious diseases, due consideration must be taken of the role played by other variables, such as the increase in international travel, migration and trade, with the risk of importing parasites and vectors with the goods. In addition, the control of certain infections was possible in the past through improvements in socio-economic conditions of affected populations. However, the reduction in resources allocated to health care has recently led to the re-emergence of diseases that were considered eradicated. PMID:25269959

  1. The Temporal Spectrum of Adult Mosquito Population Fluctuations: Conceptual and Modeling Implications

    PubMed Central

    Jian, Yun; Silvestri, Sonia; Brown, Jeff; Hickman, Rick; Marani, Marco

    2014-01-01

    An improved understanding of mosquito population dynamics under natural environmental forcing requires adequate field observations spanning the full range of temporal scales over which mosquito abundance fluctuates in natural conditions. Here we analyze a 9-year daily time series of uninterrupted observations of adult mosquito abundance for multiple mosquito species in North Carolina to identify characteristic scales of temporal variability, the processes generating them, and the representativeness of observations at different sampling resolutions. We focus in particular on Aedes vexans and Culiseta melanura and, using a combination of spectral analysis and modeling, we find significant population fluctuations with characteristic periodicity between 2 days and several years. Population dynamical modelling suggests that the observed fast fluctuations scales (2 days-weeks) are importantly affected by a varying mosquito activity in response to rapid changes in meteorological conditions, a process neglected in most representations of mosquito population dynamics. We further suggest that the range of time scales over which adult mosquito population variability takes place can be divided into three main parts. At small time scales (indicatively 2 days-1 month) observed population fluctuations are mainly driven by behavioral responses to rapid changes in weather conditions. At intermediate scales (1 to several month) environmentally-forced fluctuations in generation times, mortality rates, and density dependence determine the population characteristic response times. At longer scales (annual to multi-annual) mosquito populations follow seasonal and inter-annual environmental changes. We conclude that observations of adult mosquito populations should be based on a sub-weekly sampling frequency and that predictive models of mosquito abundance must include behavioral dynamics to separate the effects of a varying mosquito activity from actual changes in the abundance of the underlying population. PMID:25478861

  2. Development of guidelines for the surveillance of invasive mosquitoes in Europe

    PubMed Central

    2013-01-01

    Background The recent notifications of autochthonous cases of dengue and chikungunya in Europe prove that the region is vulnerable to these diseases in areas where known mosquito vectors (Aedes albopictus and Aedes aegypti) are present. Strengthening surveillance of these species as well as other invasive container-breeding aedine mosquito species such as Aedes atropalpus, Aedes japonicus, Aedes koreicus and Aedes triseriatus is therefore required. In order to support and harmonize surveillance activities in Europe, the European Centre for Disease Prevention and Control (ECDC) launched the production of ‘Guidelines for the surveillance of invasive mosquitoes in Europe’. This article describes these guidelines in the context of the key issues surrounding invasive mosquitoes surveillance in Europe. Methods Based on an open call for tender, ECDC granted a pan-European expert team to write the guidelines draft. It content is founded on published and grey literature, contractor’s expert knowledge, as well as appropriate field missions. Entomologists, public health experts and end users from 17 EU/EEA and neighbouring countries contributed to a reviewing and validation process. The final version of the guidelines was edited by ECDC (Additional file 1). Results The guidelines describe all procedures to be applied for the surveillance of invasive mosquito species. The first part addresses strategic issues and options to be taken by the stakeholders for the decision-making process, according to the aim and scope of surveillance, its organisation and management. As the strategy to be developed needs to be adapted to the local situation, three likely scenarios are proposed. The second part addresses all operational issues and suggests options for the activities to be implemented, i.e. key procedures for field surveillance of invasive mosquito species, methods of identification of these mosquitoes, key and optional procedures for field collection of population parameters, pathogen screening, and environmental parameters. In addition, methods for data management and analysis are recommended, as well as strategies for data dissemination and mapping. Finally, the third part provides information and support for cost estimates of the planned programmes and for the evaluation of the applied surveillance process. Conclusion The ‘Guidelines for the surveillance of invasive mosquitoes in Europe’ aim at supporting the implementation of tailored surveillance of invasive mosquito species of public health importance. They are intended to provide support to professionals involved in mosquito surveillance or control, decision/policy makers, stakeholders in public health and non-experts in mosquito surveillance. Surveillance also aims to support control of mosquito-borne diseases, including integrated vector control, and the guidelines are therefore part of a tool set for managing mosquito-borne disease risk in Europe. PMID:23866915

  3. Survey of the Mosquitoes (Diptera: Culicidae) of Mayotte

    PubMed Central

    Le Goff, Gilbert; Goodman, Steven M.; Elguero, Eric; Robert, Vincent

    2014-01-01

    A transversal survey of immature mosquitoes was conducted on Mayotte Island (France) in the Comoros Archipelago, western Indian Ocean, with the aim to inventory the Culicidae and to document inter-species relationships in different habitats. In total 420 habitats were sampled for larvae and/or pupae mosquitoes, resulting in more than 6,000 specimens. Forty species belonging to 15 genera were collected, with eight taxa integrated for the first time to the Mayotte mosquito list. The most frequently recorded species were Stegomyia aegypti, St. albopicta, Anopheles gambiae and Eretmapodites subsimplicipes, the first three species being known vectors of viruses and parasites transmitted to humans. Mean species richness in habitats ranged from 1.00 to 3.29, with notable differences between habitats. For example, water-filled axils of banana leaves, tree-holes and crab-holes had low species richness, while cut bamboo, water pools, abandoned tires and marsh and swamp water had notably higher species richness. Twenty-seven mosquito species belonging to 12 genera were routinely collected (in ?20% of at least one type of larval habitat) suggesting that multiple species play a role in the biocenosis of these aquatic habitats. Multispecies association was observed in 52% of the habitats. The co-occurrence of up to six species belonging to five genera was recorded in a single habitat. The mosquitoes of Mayotte show notable biogeographical affinities to those of Madagascar, as compared to the African continent. These two potential source areas are nearly equidistant from Mayotte, which in turn indicates biased dispersal from east to west. Our findings suggest that with relatively short-term intensive sampling in different habitats, it is possible to approach exhaustive species inventories based on collection of larvae. Mayotte, with its modest elevation range and land surface, has a notable species richness of mosquitoes with 45 well-documented species belonging to 15 genera. PMID:25004163

  4. The costs of infection and resistance as determinants of West Nile virus susceptibility in Culex mosquitoes

    PubMed Central

    2011-01-01

    Background Understanding the phenotypic consequences of interactions between arthropod-borne viruses (arboviruses) and their mosquito hosts has direct implications for predicting the evolution of these relationships and the potential for changes in epidemiological patterns. Although arboviruses are generally not highly pathogenic to mosquitoes, pathology has at times been noted. Here, in order to evaluate the potential costs of West Nile virus (WNV) infection and resistance in a primary WNV vector, and to assess the extent to which virus-vector relationships are species-specific, we performed fitness studies with and without WNV exposure using a highly susceptible Culex pipiens mosquito colony. Specifically, we measured and compared survival, fecundity, and feeding rates in bloodfed mosquitoes that were (i) infected following WNV exposure (susceptible), (ii) uninfected following WNV exposure (resistant), or (iii) unexposed. Results In contrast to our previous findings with a relatively resistant Cx. tarsalis colony, WNV infection did not alter fecundity or blood-feeding behaviour of Cx. pipiens, yet results do indicate that resistance to infection is associated with a fitness cost in terms of mosquito survival. Conclusions The identification of species-specific differences provides an evolutionary explanation for variability in vector susceptibility to arboviruses and suggests that understanding the costs of infection and resistance are important factors in determining the potential competence of vector populations for arboviruses. PMID:21975028

  5. Heartworm Disease (Dirofilaria immitis) and Their Vectors in Europe – New Distribution Trends

    PubMed Central

    Morchón, Rodrigo; Carretón, E.; González-Miguel, J.; Mellado-Hernández, I.

    2012-01-01

    Cardiopulmonary dirofilariasis is a cosmopolitan disease caused by Dirofilaria immitis, which affects mainly canids and felids. Moreover, it causes zoonotic infections, producing pulmonary dirofilariasis in humans. Heartworm disease is a vector-borne transmitted disease, thus transmission depends on the presence of competent mosquito species, which is directly related to favorable climate conditions for its development and survival. Cardiopulmonary dirofilariasis is mainly located in countries with temperate and tropical climates. Europe is one of the continents where animal dirofilariasis has been studied more extensively. In this article we review the current prevalence of canine and feline cardiopulmonary dirofilariasis in the European continent, the transmission vectors, the current changes in the distribution and the possible causes, though the analysis of the epidemiological studies carried out until 2001 and between 2002 and 2011. The highest prevalences have been observed in the southern European countries, which are considered historically endemic/hyperendemic countries. Studies carried out in the last 10?years suggest an expansion of cardiopulmonary dirofilariasis in dogs toward central and northern Europe. Several factors can exert an influence on the spreading of the disease, such as movement of infected animals, the introduction of new species of mosquitoes able to act as vectors, the climate change caused by the global warming, and development of human activity in new areas. Veterinary controls to prevent the spreading of this disease, programs of control of vectors, and adequate protocols of prevention of dirofilariasis in the susceptible species should be carried out. PMID:22701433

  6. Vector infection determinants of Venezuelan equine encephalitis virus reside within the E2 envelope glycoprotein.

    PubMed

    Brault, Aaron C; Powers, Ann M; Weaver, Scott C

    2002-06-01

    Epizootic subtype IAB and IC Venezuelan equine encephalitis viruses (VEEV) readily infect the epizootic mosquito vector Aedes taeniorhynchus. The inability of enzootic subtype IE viruses to infect this mosquito species provides a model system for the identification of natural viral determinants of vector infectivity. To map mosquito infection determinants, reciprocal chimeric viruses generated from epizootic subtype IAB and enzootic IE VEEV were tested for mosquito infectivity. Chimeras containing the IAB epizootic structural gene region and, more specifically, the IAB PE2 envelope glycoprotein E2 precursor gene demonstrated an efficient infection phenotype. Introduction of the PE2 gene from an enzootic subtype ID virus into an epizootic IAB or IC genetic backbone resulted in lower infection rates than those of the epizootic parent. The finding that the E2 envelope glycoprotein, the site of epitopes that define the enzootic and epizootic subtypes, also encodes mosquito infection determinants suggests that selection for efficient infection of epizootic mosquito vectors may mediate VEE emergence. PMID:12021373

  7. The unexpected importance of mosquito oviposition behaviour for malaria: non-productive larval habitats can be sources for malaria transmission

    PubMed Central

    Menach, Arnaud Le; McKenzie, F Ellis; Flahault, Antoine; Smith, David L

    2005-01-01

    Background Mosquitoes commute between blood-meal hosts and water. Thus, heterogeneity in human biting reflects underlying spatial heterogeneity in the distribution and suitability of larval habitat as well as inherent differences in the attractiveness, suitability and distribution of blood-meal hosts. One of the possible strategies of malaria control is to identify local vector species and then attack water bodies that contain their larvae. Methods Biting and host seeking, not oviposition, have been the focus of most previous studies of mosquitoes and malaria transmission. This study presents a mathematical model that incorporates mosquito oviposition behaviour. Results The model demonstrates that oviposition is one potential factor explaining heterogeneous biting and vector distribution in a landscape with a heterogeneous distribution of larval habitat. Adult female mosquitoes tend to aggregate around places where they oviposit, thereby increasing the risk of malaria, regardless of the suitability of the habitat for larval development. Thus, a water body may be unsuitable for adult mosquito emergence, but simultaneously, be a source for human malaria. Conclusion Larval density may be a misleading indicator of a habitat's importance for malaria control. Even if mosquitoes could be lured to oviposit in sprayed larval habitats, this would not necessarily mitigate – and might aggravate – the risk of malaria transmission. Forcing mosquitoes to fly away from humans in search of larval habitat may be a more efficient way to reduce the risk of malaria than killing larvae. Thus, draining, fouling, or filling standing water where mosquitoes oviposit can be more effective than applying larvicide. PMID:15892886

  8. Evans Blue as a Simple Method to Discriminate Mosquitoes’ Feeding Choice on Small Laboratory Animals

    PubMed Central

    Maciel, Ceres; Fujita, André; Gueroni, Daniele I.; Ramos, Anderson D.; Capurro, Margareth L.; Sá-Nunes, Anderson

    2014-01-01

    Background Temperature, humidity, vision, and particularly odor, are external cues that play essential roles to mosquito blood feeding and oviposition. Entomological and behavioral studies employ well-established methods to evaluate mosquito attraction or repellency and to identify the source of the blood meal. Despite the efficacy of such methods, the costs involved in the production or acquisition of all parts, components and the chemical reagents involved are unaffordable for most researchers from poor countries. Thus, a simple and relatively low-cost method capable of evaluating mosquito preferences and the blood volume ingested is desirable. Principal Findings By using Evans blue (EB) vital dye and few standard laboratory supplies, we developed and validated a system capable of evaluating mosquito’s choice between two different host sources of blood. EB-injected and PBS-injected mice submitted to a number of situations were placed side by side on the top of a rounded recipient covered with tulle fabric and containing Aedes aegypti mosquitoes. Homogenates from engorged mosquitoes clearly revealed the blood source (EB- or PBS-injected host), either visually or spectrometrically. This method was able to estimate the number of engorded mosquitoes, the volume of blood ingested, the efficacy of a commercial repellent and the attractant effects of black color and human sweat. Significance Despite the obvious limitations due to its simplicity and to the dependence of a live source of blood, the present method can be used to assess a number of host variables (diet, aging, immunity, etc) and optimized for several aspects of mosquito blood feeding and vector-host interactions. Thus, it is proposed as an alternative to field studies, and it could be used for initial screenings of chemical compound candidates for repellents or attractants, since it replicates natural conditions of exposure to mosquitoes in a laboratory environment. PMID:25333369

  9. Insecticide resistance in disease vectors from Mayotte: an opportunity for integrated vector management

    PubMed Central

    2014-01-01

    Background Mayotte, a small island in the Indian Ocean, has been affected for many years by vector-borne diseases. Malaria, Bancroftian filariasis, dengue, chikungunya and Rift Valley fever have circulated or still circulate on the island. They are all transmitted by Culicidae mosquitoes. To limit the impact of these diseases on human health, vector control has been implemented for more than 60 years on Mayotte. In this study, we assessed the resistance levels of four major vector species (Anopheles gambiae, Culex pipiens quinquefasciatus, Aedes aegypti and Aedes albopictus) to two types of insecticides: i) the locally currently-used insecticides (organophosphates, pyrethroids) and ii) alternative molecules that are promising for vector control and come from different insecticide families (bacterial toxins or insect growth regulators). When some resistance was found to one of these insecticides, we characterized the mechanisms involved. Methods Larval and adult bioassays were used to evaluate the level of resistance. When resistance was found, we tested for the presence of metabolic resistance through detoxifying enzyme activity assays, or for target-site mutations through molecular identification of known resistance alleles. Results Resistance to currently-used insecticides varied greatly between the four vector species. While no resistance to any insecticides was found in the two Aedes species, bioassays confirmed multiple resistance in Cx. p. quinquefasciatus (temephos: ~ 20 fold and deltamethrin: only 10% mortality after 24 hours). In An. gambiae, resistance was scarce: only a moderate resistance to temephos was found (~5 fold). This resistance appears to be due only to carboxyl-esterase overexpression and not to target modification. Finally, and comfortingly, none of the four species showed resistance to any of the new insecticides. Conclusions The low resistance observed in Mayotte’s main disease vectors is particularly interesting, because it leaves a range of tools useable by vector control services. Together with the relative isolation of the island (thus limited immigration of mosquitoes), it provides us with a unique place to implement an integrated vector management plan, including all the good practices learned from previous experiences. PMID:24984704

  10. Progress in malaria vector control*

    PubMed Central

    Pant, C. P.; Rishikesh, N.; Bang, Y. H.; Smith, A.

    1981-01-01

    Malaria control, except in tropical Africa, will probably continue to be based to a large extent on the use of insecticides for many years. However, the development of resistance to insecticides in the vectors has caused serious difficulties and it is necessary to change the strategy of insecticide use to maximize their efficacy. A thorough knowledge of the ecology and behaviour of each vector species is required before the control strategy can be adapted to different epidemiological situations. The behavioural differences between sibling species have been recognized for several years, but study of this problem has recently been simplified by improved means of identification that involve chromosomal banding patterns and electrophoretic analysis. Behavioural differences have also been associated with certain chromosomal rearrangements. New records of insecticide resistance among anophelines continue to appear and the impact of this on antimalaria operations has been seriously felt in Central America (multi-resistance in Anopheles albimanus), Turkey (A. sacharovi), India and several Asian countries (A. culicifacies and A. stephensi), and some other countries. Work continues on the screening and testing of newer insecticides that can be used as alternatives, but DDT, malathion, temephos, fenitrothion, and propoxur continue to be used as the main insecticides in many malaria control projects. The search for simpler and innovative approaches to insecticide application also continues. Biological control of vectors is receiving increased attention, as it could become an important component of integrated vector control strategies, and most progress has been made with the spore-forming bacterium, serotype H-14 of Bacillus thuringiensis. Larvivorous fish such as Gambusia spp. and Poecilia spp. continue to be used in some programmes. Application of environmental management measures, such as source reduction, source elimination, flushing of drainage and irrigation channels, and intermittent irrigation have been re-examined and currently a great deal of interest is being shown in these approaches. There has been limited interest in the genetic control of mosquitos and the phenomenon of refractoriness in some strains of the disease vectors, with the idea of replacing the vector species with the refractory strain. More research is needed before this approach can become a practical tool. It is apparent that in future a more integrated approach will have to be used for vector control within the context of antimalaria programmes. Training of staff, research, and cooperation at all levels will be an essential requirement for this approach. PMID:6976842

  11. Challenges and Approaches for Mosquito Targeted Malaria Control

    PubMed Central

    Ramirez, José L.; Garver, Lindsey S.; Dimopoulos, George

    2010-01-01

    Malaria is one of today’s most serious diseases with an enormous socioeconomic impact. While anti-malarial drugs have existed for some time and vaccines development may be underway, the most successful malaria eradication programs have thus far relied on attacking the mosquito vector that spreads the disease causing agent Plasmodium. Here we will review past, current and future perspectives of malaria vector control strategies and how these approaches have taken a promising turn thanks recent advances in functional genomics and molecular biology. PMID:19275622

  12. Gene Expression Studies in Mosquitoes

    PubMed Central

    Chen, Xlao-Guang; Mathur, Geetika; James, Anthony A.

    2009-01-01

    Research on gene expression in mosquitoes is motivated by both basic and applied interests. Studies of genes involved in hematophagy, reproduction, olfaction, and immune responses reveal an exquisite confluence of biological adaptations that result in these highly-successful life forms. The requirement of female mosquitoes for a bloodmeal for propagation has been exploited by a wide diversity of viral, protozoan and metazoan pathogens as part of their life cycles. Identifying genes involved in host-seeking, blood feeding and digestion, reproduction, insecticide resistance and susceptibility/refractoriness to pathogen development is expected to provide the bases for the development of novel methods to control mosquito-borne diseases. Advances in mosquito transgenesis technologies, the availability of whole genome sequence information, mass sequencing and analyses of transcriptomes and RNAi techniques will assist development of these tools as well as deepen the understanding of the underlying genetic components for biological phenomena characteristic of these insect species. PMID:19161831

  13. Field testing of different chemical combinations as odour baits for trapping wild mosquitoes in The Gambia.

    PubMed

    Jawara, Musa; Awolola, Taiwo S; Pinder, Margaret; Jeffries, David; Smallegange, Renate C; Takken, Willem; Conway, David J

    2011-01-01

    Odour baited traps have potential use in population surveillance of insect vectors of disease, and in some cases for vector population reduction. Established attractants for human host-seeking mosquitoes include a combination of CO(2) with L-lactic acid and ammonia, on top of which additional candidate compounds are being tested. In this field study in rural Gambia, using Latin square experiments with thorough randomization and replication, we tested nine different leading candidate combinations of chemical odorants for attractiveness to wild mosquitoes including anthropophilic malaria vectors, using modified Mosquito Magnet-X (MM-X) counterflow traps outside experimental huts containing male human sleepers. Highest catches of female mosquitoes, particularly of An. gambiae s.l. and Mansonia species, were obtained by incorporation of tetradecanoic acid. As additional carboxylic acids did not increase the trap catches further, this 'reference blend' (tetradecanoic acid with L-lactic acid, ammonia and CO(2)) was used in subsequent experiments. MM-X traps with this blend caught similar numbers of An. gambiae s.l. and slightly more Mansonia and Culex mosquitoes than a standard CDC light trap, and these numbers were not significantly affected by the presence or absence of human sleepers in the huts. Experiments with CO(2) produced from overnight yeast cultures showed that this organic source was effective in enabling trap attractiveness for all mosquito species, although at a slightly lower efficiency than obtained with use of CO(2) gas cylinders. Although further studies are needed to discover additional chemicals that increase attractiveness, as well as to optimise trap design and CO(2) source for broader practical use, the odour-baited traps described here are safe and effective for sampling host-seeking mosquitoes outdoors and can be incorporated into studies of malaria vector ecology. PMID:21637337

  14. Prallethrin-induced excitation increases contact between sprayed ultra-low-volume droplets and flying mosquitoes (Diptera: Culicidae) in a wind tunnel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes are important in the United States due to their roles as pestiferous biters and vectors of diseases such as West Nile Virus and Dengue. Conventional applications of pesticides in spray clouds are often limited by their ability to contact and kill mosquitoes that may be resting or hiding ...

  15. Synthesis and structure-activity relationships of 1-undec-10-enoyl-piperidines as adulticides against the yellow fever mosquito Aedes aegypti (Diptera: Culicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yellow fever mosquito, Aedes aegypti (L.), is considered the primary vector for both dengue and yellow fever. Using insecticide is one of the major ways to control this medically important insect pest. However, few new insecticides have been developed for mosquito control. As part of our collabo...

  16. Mosquito Control Around the Home 

    E-print Network

    Jackman, John A.; Olson, Jimmy K.

    2003-03-17

    for mosquitoes. Drain water from flower pots, bird baths, rain gutters, rain barrels, birdbaths, pet dishes, livestock watering troughs, etc. at least once a week. ? Empty your plastic wading pool weekly and store it indoors when not in use. ? Fill holes... on the product label. Avoid contact with mosquitoes ? Use screening in your homes and pet kennels. Keep the screens in good repair and be sure that they seal around the frames of the door or window. ? Schedule outdoor activities during times when...

  17. Eliminating malaria vectors

    PubMed Central

    2013-01-01

    Malaria vectors which predominantly feed indoors upon humans have been locally eliminated from several settings with insecticide treated nets (ITNs), indoor residual spraying or larval source management. Recent dramatic declines of An. gambiae in east Africa with imperfect ITN coverage suggest mosquito populations can rapidly collapse when forced below realistically achievable, non-zero thresholds of density and supporting resource availability. Here we explain why insecticide-based mosquito elimination strategies are feasible, desirable and can be extended to a wider variety of species by expanding the vector control arsenal to cover a broader spectrum of the resources they need to survive. The greatest advantage of eliminating mosquitoes, rather than merely controlling them, is that this precludes local selection for behavioural or physiological resistance traits. The greatest challenges are therefore to achieve high biological coverage of targeted resources rapidly enough to prevent local emergence of resistance and to then continually exclude, monitor for and respond to re-invasion from external populations. PMID:23758937

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

    PubMed Central

    TOTTEN, Daniel C.; VUONG, Mai; LITVINOVA, Oksana V.; JINWAL, Umesh K.; GULIA-NUSS, Monika; HARRELL, Robert A.; BENEŠ, Helen

    2014-01-01

    As the fat body is a critical tissue for mosquito development, metamorphosis, immune and reproductive system function, characterization of regulatory modules targeting gene expression to the female mosquito fat body at distinct life stages is much needed for multiple, varied strategies for controlling vector-borne diseases such as dengue and malaria. The hexameric storage protein, Hexamerin-1.2, of the mosquito, Aedes atropalpus, is female-specific and uniquely expressed in the fat body of fourth-instar larvae and young adults. We have identified in the Hex-1.2 gene, a short regulatory module that directs female-, tissue-, and stage-specific lacZ reporter gene expression using a heterologous promoter in transgenic lines of the dengue vector, Aedes aegypti. Male transgenic larvae and pupae of one line expressed no E. coli ?-galactosidase or transgene product; in two other lines reporter gene activity was highly female-biased. All transgenic lines expressed the reporter only in the fat body. However, lacZ mRNA levels were no different in males and females at all stages examined, suggesting that the gene regulatory module drives female-specific expression by post-transcriptional regulation in the heterologous mosquito. This regulatory element from the Hex-1.2 gene thus provides a new molecular tool for transgenic mosquito control as well as functional genetic analysis in aedine mosquitoes. PMID:23241066

  19. Fauna and Larval Habitats of Mosquitoes (Diptera: Culicidae) of West Azerbaijan Province, Northwestern Iran

    PubMed Central

    Khoshdel-Nezamiha, Farahnaz; Vatandoost, Hassan; Azari-Hamidian, Shahyad; Bavani, Mulood Mohammadi; Dabiri, Farrokh; Entezar-Mahdi, Rasool; Chavshin, Ali Reza

    2014-01-01

    Background: Several important diseases are transmitted by mosquitoes. Despite of the potential of the occurrence of some mosquito-borne diseases such as West Nile, dirofilariasis and malaria in the region, there is no recent study of mosquitoes in West Azerbaijan Province. The aim of this investigation was to study the fauna, composition and distribution of mosquitoes and the characteristics of their larval habitats in this province. Methods: Larvae and adult collections were carried out from different habitats using the standard methods in twenty five localities of seven counties across West Azerbaijan Province. Results: Overall, 1569 mosquitoes including 1336 larvae and 233 adults were collected from 25 localities. The details of geographical properties were recorded. Five genera along with 12 species were collected and identified including: Anopheles claviger, An. maculipennis s.l., An. superpictus, Culex pipiens, Cx. theileri, Cx. modestus, Cx. hortensis, Cx. mimeticus, Culiseta Longiareolata, Ochlerotatus caspius s.l., Oc. geniculatus and Uranotaenia unguiculata. This is the first record of Oc. geniculatus in the province. Conclusion: Due to the geographical location of the West Azerbaijan Province, it comprises different climatic condition which provides suitable environment for the establishment of various species of mosquitoes. The solidarity geographical, cultural and territorial exchanges complicate the situation of the province and its vectors as a threat for future and probable epidemics of mosquito-borne diseases.

  20. An improved trap to capture adult container-inhabiting mosquitoes.

    PubMed

    Barrera, Roberto; Mackay, Andrew J; Amador, Manuel

    2013-12-01

    Although dengue viruses are thought to be transmitted by Aedes aegypti in Puerto Rico, Aedes mediovittatus, the Caribbean tree hole mosquito, is also a potential vector. This species is native to the Greater Antilles and has been shown to be a competent vector of dengue viruses in the laboratory. Consequently, it has been suggested that Ae. mediovittatus could be acting as a secondary vector or virus reservoir. This study was part of an ongoing investigation into this, and it aimed to determine whether BG-Sentinel traps (BGS traps) could be used to collect adults of this mosquito and could be modified to increase the number of captures of this species in the field. We conducted experiments to test the relative attractiveness of BGS traps to Ae. mediovittatus and Ae. aegypti and explored the effects of chemical lures (BG-Lure, CO2, octenol) and optical properties (color, size) on the capture rates of BGS traps in a large, outdoor cage in San Juan city, Puerto Rico. We also conducted field tests to compare modified BGS traps with the original traps in a rural community in Patillas municipality, Puerto Rico. Results obtained from the large, outdoor cage experiments indicated that trap captures of both mosquito species could be significantly enhanced by using black instead of white BGS traps combined with BG-Lure. Field experiments revealed that the modified traps captured a significantly greater number of Ae. aegypti, Ae. mediovittatus, and Culex quinquefasciatus, with greater sensitivity for the latter 2 species, and also captured a larger number of mosquito species and a smaller ratio of Ae. aegypti to Ae. mediovittatus, with greater than expected species co-occurrences. PMID:24551969

  1. Interleukin-10 overexpression does not synergize with the neuroprotective action of RGD-containing vectors after postnatal brain excitotoxicity but modulates the main inflammatory cell responses.

    PubMed

    Gonzalez, Pau; Peluffo, Hugo; Acarin, Laia; Villaverde, Antonio; Gonzalez, Berta; Castellano, Bernardo

    2012-01-01

    Antiinflammatory cytokines such as interleukin-10 (IL-10) have been used to modulate and terminate inflammation and provide neuroprotection. Recently, we reported that the modular recombinant transfection vector NLSCt is an efficient tool for transgene overexpression in vivo, which induces neuroprotection as a result of its RGD-mediated integrin-interacting capacity. We here sought to evaluate the putative synergic neuroprotective action exerted by IL-10 overexpression using NLSCt as a transfection vector after an excitotoxic injury to the postnatal rat brain. For this purpose, lesion volume, neurodegeneration, astroglial and microglial responses, neutrophil infiltration, and proinflammatory cytokine production were analyzed at several survival times after intracortical NMDA injection in postnatal day 9 rats, followed by injection of NLSCt combined with the IL-10 gene, a control transgene, or saline vehicle solution. Our results show no combined neuroprotective effect between RGD-interacting vectors and IL-10 gene therapy; instead, IL-10 overexpression using NLSCt as transfection vector increased lesion volume and neuronal degeneration at 12 hr and 3 days postlesion. In parallel, NLSCt/IL-10 treated animals displayed increased density of neutrophils and microglia/macrophages, and a reduced astroglial content of GFAP and vimentin. Moreover, NLSCt/IL-10 treated animals did not show any variation in interleukin-1? or tumor necrosis factor-? expression but a slight increase in interleukin-6 content at 7 days postlesion. In conclusion, overexpression of IL-10 by using NLSCt transfection vector did not synergistically neuroprotect the excitotoxically damaged postnatal rat brain but induced changes in the astroglial and microglial and inflammatory cell response. PMID:21922521

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

    PubMed

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

    2013-01-01

    The mosquito Aedes aegypti is an epidemic vector of several diseases such as dengue fever and yellow fever. Several pesticides are used to control the mosquito population. Because of their frequent use, some mosquitoes have developed resistance. In this study, we used the Y-tube olfactometer to test essential oils of Cymbopogon species and screened specific formulas of components as repellents against Ae. aegypti. At 400 ?L, the extracted oil of citronella grass (Cymbopogon nardus) and myrcene produced a low-active response by inhibiting mosquito host-seeking activity. Citronella grass, lemon grass (Cymbopogon citratus), citral and myrcene also produced a low-treatment response to repellents, for more potential to affect host-seeking behavior. Furthermore, the mixture of citral, myrcene, and citronellal oil (C:M:Ci = 6:4:1) greatly affected and inhibited host-seeking behavior (76% active response; 26% treatment response with 40 ?L; 42.5%, 18% with 400 ?L; and 19%, 23% with 1000 ?L). As compared with the result for N,N-diethyl-3-methylbenzamide (DEET; 44%, 22% with 400 ?L), adjusting the composition formulas of citronella oil had a synergistic effect, for more effective repellent against Ae. aegypti. PMID:23998314

  3. Mosquito odorant receptor for DEET and methyl jasmonate

    PubMed Central

    Xu, Pingxi; Choo, Young-Moo; De La Rosa, Alyssa; Leal, Walter S.

    2014-01-01

    Insect repellents are important prophylactic tools for travelers and populations living in endemic areas of malaria, dengue, encephalitis, and other vector-borne diseases. DEET (N,N-diethyl-3-methylbenzamide) is a 6-decade-old synthetic repellent, which is still considered the gold standard of mosquito repellents. Mosquitoes use their sense of smell to detect DEET, but there are currently two hypotheses regarding its mode of action: activation of ionotropic receptor IR40a vs. odorant receptor(s). Here, we demonstrate that DEET, picaridin, insect repellent 3535, and p-menthan-3,8-diol activate the odorant receptor CquiOR136 of the southern house mosquito, Culex quinquefasciatus. Electrophysiological and behavioral assays showed that CquiIR40a knockdown had no significant effect on DEET detection and repellency. By contrast, reduction of CquiOR136 transcript levels led to a significant decrease in electroantennographic responses to DEET and a complete lack of repellency. Thus, direct activation of an odorant receptor, not an ionotropic receptor, is necessary for DEET reception and repellency in Culex mosquitoes. Interestingly, methyl jasmonate, a repellent derived from the nonvolatile jasmonic acid in the signaling pathway of plant defenses, elicited robust responses in CquiOR136•CquiOrco-expressing Xenopus oocytes, thus suggesting a possible link between natural products with long insect–plant evolutionary history and synthetic repellents. PMID:25349401

  4. Direct broad-range detection of alphaviruses in mosquito extracts.

    PubMed

    Eshoo, Mark W; Whitehouse, Chris A; Zoll, Scott T; Massire, Christian; Pennella, Thuy-Trang D; Blyn, Lawrence B; Sampath, Rangarajan; Hall, Thomas A; Ecker, Joseph A; Desai, Anjali; Wasieloski, Leonard P; Li, Feng; Turell, Michael J; Schink, Amy; Rudnick, Karl; Otero, Glen; Weaver, Scott C; Ludwig, George V; Hofstadler, Steven A; Ecker, David J

    2007-11-25

    Members of the genus Alphavirus are a diverse group of principally mosquito-borne RNA viruses. There are at least 29 species and many more subtypes of alphaviruses and some are considered potential bioweapons. We have developed a multi-locus RT-PCR followed by electrospray ionization mass spectrometry (RT-PCR/ESI-MS) assay that uses the amplicon base compositions to detect and identify alphaviruses. A small set of primer pairs targeting conserved sites in the alphavirus RNA genome were used to amplify a panel of 36 virus isolates representing characterized Old World and New World alphaviruses. Base compositions from the resulting amplicons could be used to unambiguously determine the species or subtype of 35 of the 36 isolates. The assay detected, without culture, Venezuelan equine encephalitis virus (VEEV), Eastern equine encephalitis virus (EEEV), and mixtures of both in pools consisting of laboratory-infected and -uninfected mosquitoes. Further, the assay was used to detect alphaviruses in naturally occurring mosquito vectors collected from locations in South America and Asia. Mosquito pools collected near Iquitos, Peru, were found to contain an alphavirus with a very distinct signature. Subsequent sequence analysis confirmed that the virus was a member of the Mucambo virus species (subtype IIID in the VEEV complex). The assay we have developed provides a rapid, accurate, and high-throughput assay for surveillance of alphaviruses. PMID:17655905

  5. The effect of Mosquito Magnet Liberty Plus trap on the human mosquito biting rate under semi-field conditions.

    PubMed

    Kitau, Jovin; Pates, Helen; Rwegoshora, Theophil R; Rwegoshora, Dionis; Matowo, Johnson; Kweka, Eliningaya J; Mosha, Franklin W; McKenzie, Karen; Magesa, Stephen M

    2010-09-01

    This study evaluated the efficacy of a commercially available mosquito trap, the Mosquito Magnet Liberty Plus (MM), in reducing human biting rates under semi-field conditions when used alone or with different types of repellents. The MM trap significantly reduced the human biting rate with both laboratory-reared Culex quinquefasciatus and Anopheles gambiae sensu stricto. The MM trap catch did not increase when a mosquito coil was burned but did significantly increase when a skin repellent was applied to the human bait. Microencapsulated repellent ankle bands did not increase the MM trap catch with either Cx. quinquefasciatus or An. gambiae s.s., although its combination with the trap was more effective at reducing bites by Cx. quinquefasciatus. The absence of the commercial attractant Lurex3 in traps significantly lowered the catch efficiency of Cx. quinquefasciatus even when the skin repellent was applied to volunteers. The results from this study showed that the use of a skin repellent and an attractant-baited trap can significantly reduce the human biting rate of both nuisance biting mosquitoes and malaria vectors. Further work is required to investigate how this push-pull system would work in a field environment. PMID:21033055

  6. Venezuelan equine encephalitis virus infection of mosquito cells requires acidification as well as mosquito homologs of the endocytic proteins Rab5 and Rab7.

    PubMed

    Colpitts, Tonya M; Moore, Andrew C; Kolokoltsov, Andrey A; Davey, Robert A

    2007-12-01

    Venezuelan equine encephalitis virus (VEEV) is a New World alphavirus that can cause fatal encephalitis in humans. It remains a naturally emerging disease as well as a highly developed biological weapon. VEEV is transmitted to humans in nature by mosquito vectors. Little is known about VEEV entry, especially in mosquito cells. Here, a novel luciferase-based virus entry assay is used to show that the entry of VEEV into mosquito cells requires acidification. Furthermore, mosquito homologs of key human proteins (Rab5 and Rab7) involved in endocytosis were isolated and characterized. Rab5 is found on early endosomes and Rab7 on late endosomes and both are important for VEEV entry in mammalian cells. Each was shown to have analogous function in mosquito cells to that seen in mammalian cells. The wild-type, dominant negative and constitutively active mutants were then used to demonstrate that VEEV requires passage through early and late endosomes before infection can take place. This work indicates that the infection mechanism in mosquitoes and mammals is through a common and ancient evolutionarily conserved pathway. PMID:17707875

  7. Absence of Close-Range Excitorepellent Effects in Malaria Mosquitoes Exposed to Deltamethrin-Treated Bed Nets

    PubMed Central

    Spitzen, Jeroen; Ponzio, Camille; Koenraadt, Constantianus J. M.; Pates Jamet, Helen V.; Takken, Willem

    2014-01-01

    Flight behavior of insecticide-resistant and susceptible malaria mosquitoes approaching deltamethrin-treated nets was examined using a wind tunnel. Behavior was linked to resulting health status (dead or alive) using comparisons between outcomes from free-flight assays and standard World Health Organization (WHO) bioassays. There was no difference in response time, latency time to reach the net, or spatial distribution in the wind tunnel between treatments. Unaffected resistant mosquitoes spent less time close to (< 30 cm) treated nets. Nettings that caused high knockdown or mortality in standard WHO assays evoked significantly less mortality in the wind tunnel; there was no excitorepellent effect in mosquitoes making contact with the nettings in free flight. This study shows a new approach to understanding mosquito behavior near insecticidal nets. The methodology links free-flight behavior to mosquito health status on exposure to nets. The results suggest that behavioral assays can provide important insights for evaluation of insecticidal effects on disease vectors. PMID:24752686

  8. Understanding the Long-Lasting Attraction of Malaria Mosquitoes to Odor Baits

    PubMed Central

    Mweresa, Collins K.; Otieno, Bruno; Omusula, Philemon; Weldegergis, Berhane T.; Verhulst, Niels O.; Dicke, Marcel; van Loon, Joop J. A.; Takken, Willem; Mukabana, Wolfgang R.

    2015-01-01

    The use of odor baits for surveillance and control of malaria mosquitoes requires robust dispensing tools. In this study, the residual activity of a synthetic mosquito attractant blend dispensed from nylon or low density polyethylene (LDPE) sachets was evaluated at weekly intervals for one year without re-impregnation. The potential role of bacteria in modulating the attraction of mosquitoes to odor-treated nylon that had been used repeatedly over the one year study period, without re-impregnation, was also investigated. Significantly higher proportions of female Anopheles gambiae sensu stricto mosquitoes were consistently attracted to treated nylon strips than the other treatments, up to one year post-treatment. Additional volatile organic compounds and various bacterial populations were found on the treated nylon strips after one year of repeated use. The most abundant bacteria were Bacillus thuringiensis and Acinetobacter baumannii. Autoclaving of treated nylon strips prior to exposure had no effect on trap collections of laboratory-reared female An. Gambiae (P = 0.17) or wild female An. Gambiae sensu lato (P = 0.26) and Mansonia spp. (P = 0.17) mosquitoes. Trap catches of wild female An. Funestus (P < 0.001) and other anophelines (P < 0.007) were higher when treated strips had been autoclaved prior to deployment as opposed to when the treated nylon strips were not autoclaved. By contrast, wild female Culex mosquitoes were more strongly attracted to non-autoclaved compared to autoclaved treated nylon strips (P < 0.042). This study demonstrates the feasibility of using odor baits for sampling and surveillance of malaria as well as other mosquito vectors over prolonged periods of time. Preliminary evidence points towards the potential role of bacteria in sustaining prolonged use of nylon material for dispensing synthetic attractant odorants for host-seeking malaria and other mosquito vectors but further investigations are required. PMID:25798818

  9. Understanding the long-lasting attraction of malaria mosquitoes to odor baits.

    PubMed

    Mweresa, Collins K; Otieno, Bruno; Omusula, Philemon; Weldegergis, Berhane T; Verhulst, Niels O; Dicke, Marcel; van Loon, Joop J A; Takken, Willem; Mukabana, Wolfgang R

    2015-01-01

    The use of odor baits for surveillance and control of malaria mosquitoes requires robust dispensing tools. In this study, the residual activity of a synthetic mosquito attractant blend dispensed from nylon or low density polyethylene (LDPE) sachets was evaluated at weekly intervals for one year without re-impregnation. The potential role of bacteria in modulating the attraction of mosquitoes to odor-treated nylon that had been used repeatedly over the one year study period, without re-impregnation, was also investigated. Significantly higher proportions of female Anopheles gambiae sensu stricto mosquitoes were consistently attracted to treated nylon strips than the other treatments, up to one year post-treatment. Additional volatile organic compounds and various bacterial populations were found on the treated nylon strips after one year of repeated use. The most abundant bacteria were Bacillus thuringiensis and Acinetobacter baumannii. Autoclaving of treated nylon strips prior to exposure had no effect on trap collections of laboratory-reared female An. Gambiae (P = 0.17) or wild female An. Gambiae sensu lato (P = 0.26) and Mansonia spp. (P = 0.17) mosquitoes. Trap catches of wild female An. Funestus (P < 0.001) and other anophelines (P < 0.007) were higher when treated strips had been autoclaved prior to deployment as opposed to when the treated nylon strips were not autoclaved. By contrast, wild female Culex mosquitoes were more strongly attracted to non-autoclaved compared to autoclaved treated nylon strips (P < 0.042). This study demonstrates the feasibility of using odor baits for sampling and surveillance of malaria as well as other mosquito vectors over prolonged periods of time. Preliminary evidence points towards the potential role of bacteria in sustaining prolonged use of nylon material for dispensing synthetic attractant odorants for host-seeking malaria and other mosquito vectors but further investigations are required. PMID:25798818

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

    PubMed

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

    2005-01-01

    Few Aedes aegypti females were found when collecting the mosquitoes attacking human beings in the Central District of Sochi in August to September 2001-2004. Ae. aegypti, a vector of dangerous causative agents of diseases, such as yellow and Aden fevers, appeared on the Black Sea coast of the Caucasus is recorded after its long absence. By taking into account the potential epidemic value of Ae. aegypti, it is necessary to make a monitoring in the cities, towns, and settlements to establish the spread, number, and the breading sites of mosquitoes in the given area and to prevent their mass reproduction. The effectiveness of Ae. albopictus as a vector of Aden fever has been established in different regions of the world. Entomological surveys for Ae. albopictus should be made in the areas of Russia where Ae. aegypti mosquitoes were distributed early in the past century, particularly in the southern port towns and settlements of Russia. Ae. albopictus is potentially able to spread to the north further than is Ae. aegypti. PMID:16212085

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

    PubMed Central

    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 against peridomestic mosquitoes. PMID:25255027

  12. Population interactions between Culex vishnui mosquitoes and their natural enemies in Pondicherry, India.

    PubMed

    Das, P K; Sivagnaname, N; Amalraj, D Dominic

    2006-06-01

    Population interactions among mosquitoes in the Culex vishnui subgroup, which are vectors of Japanese Encephalitis, and their natural enemies were studied in Pondicherry, India. We tested the hypothesis that the breakdown of interactions between the larvae and their natural enemies due to drought followed by rain was responsible for the sudden increase in the vector population above the threshold for disease transmission during the heavy rainy period. We randomly sampled mosquito larvae and their predators in different breeding habitats and subjected the mean densities of prey, predator, and mosquito larvae infected with parasites/pathogens to covariate analysis to understand the interaction between prey and their natural enemies in relation to environmental factors. In rice fields, neither prey nor predator showed any positive correlation with temperature, RH, or the number of rainy days. However, the pathogen/parasite of mosquito immatures showed a positive correlation with RH. Among the mosquito predators, notonectids exhibited a significant positive correlation with Cx. vishnui larvae. The parasitic Romanomermis iyengari and pathogenic Coelomomyces anopheliscus also showed positive correlations with immatures. No parasites and pathogens of mosquito larvae were recorded in shallow water pools (SWP) or cement tanks (CT) during the study period. Important predators recorded in SWP were notonectids, damselfly nymphs, Diplonychus indicus, and hydrophilids. Dragonfly nymphs, gerrids, and tadpole shrimps were recorded in CT. In CT, prey and their predators were positively correlated with RH and rainy days. In SWP, there was a highly significant correlation between prey, predators and environmental factors. We conclude that rice fields are a stable ecosystem where regular interaction occurs between larvae and their natural enemies and a sudden increase in mosquito populations is uncommon. In transient habitats, no such stability is present and they become more important as breeding habitats in terms of seasonality and number. Shallow water pools should be seriously considered for the control of these vectors. PMID:16859094

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

    PubMed

    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

  14. Bioactivity of Dianthus caryophyllus, Lepidium sativum, Pimpinella anisum, and Illicium verum essential oils and their major components against the West Nile vector Culex pipiens.

    PubMed

    Kimbaris, Athanasios C; Koliopoulos, George; Michaelakis, Antonios; Konstantopoulou, Maria A

    2012-12-01

    Mosquitoes constitute a severe health problem in many areas all over the world. There are many regions of the tropics and subtropics where mosquitoes are one of the main reasons for inhibiting the economic upgrade. Except nuisance, their medical importance is another matter of attention since mosquitoes are vectors for a wide variety of vector-borne diseases. Due to disadvantages of currently used chemical control methods, it is unavoidable to search for eco-friendly new molecules. We report herein the evaluation of the larvicidal effect exhibited by essential oils of Dianthus caryophyllus, Lepidium sativum, Pimpinella anisum, and Illicium verum against late third to early fourth instar mosquito larvae of Culex pipiens. Furthermore, phytochemical analysis of plant samples revealed their major compounds to be ?-caryophyllene, eugenol, eucalyptol, ?-terpinyl acetate, and (E)-anethole which were also tested for their potential larvicidal activity. For D. caryophyllus and L. sativum, this was the first report on the chemical composition of their essential oils. The essential oils of I. verum and P. anisum demonstrated high larvicidal activity with a LC(50) <18 mg L(-1). The other two essential oils of D. caryophyllus and L. sativum revealed moderate larvicidal activity, displaying a LC(50) value above 50 mg L(-1). Among the pure components, the most toxic were eugenol, (E)-anethole, and ?-terpinyl acetate, with LC(50) values 18.28, 16.56, and 23.03 mg L(-1), respectively. Eucalyptol (1,8 cineole) and ?-caryophyllene were inactive at concentrations even as high as 100 mg L(-1), showing the least significant activity against mosquito larvae. Results allow some rationalization on the relative importance of the major compounds regarding the larvicidal activity of selected essential oils and their potential use as vector control agents. PMID:22955447

  15. Birds, Mosquitoes, and Viruses

    NSDL National Science Digital Library

    Ecohealth

    In this activity, students distinguish between direct and indirectly transmitted diseases and participate in a group game to simulate the spread of vector-borne diseases. They then research a particular pathogenic disease to learn how global warming and biodiversity loss can affect disease transmission.

  16. Community diversity of mosquitoes and their microbes across different habitats endemic for West Nile Virus and other arthropod-borne diseases

    NASA Astrophysics Data System (ADS)

    Liu, R.; Bennett, S. N.; Thongsripong, P.; Chandler, J. S.

    2013-12-01

    Mosquitoes have long been vectors for disease, and humans, birds, and other vertebrates have served their role as hosts in the transmission cycle of arthropod-borne viruses. In California, there are several mosquito species that act as vectors, transmitting such disease agents as Western equine and St. Louis encephalitis viruses, filarial nematodes, Plasmodium (which causes malaria), and West Nile virus (WNV). Last year (2012-2013), California had over 450 reported cases of West Nile Virus in humans (http://westnile.ca.gov/). To begin to understand mosquitoes and their role in the bay area as vectors of diseases, including West Nile Virus, we trapped mosquitoes from various sites and examined their microbiomes, including bacteria, fungi, viruses, and eukaryotes. Study sites were in Marin, San Mateo, and San Francisco counties, in areas that represented, respectively, rural, suburban, and urban habitats. The mosquitoes were identified through morphological characteristics, and verified molecularly by sequencing of the cytochrome oxidase I (COI) gene extracted from a leg. Most mosquitoes were collected from San Mateo and Mill Valley and were identified as Culiseta incidens. Data from traditional culture-based and next-generation 454 sequencing methods applied to mosquito whole bodies, representing their microbiomes, will be discussed, to determine how mosquito and microbial diversity varies across sites sampled in the San Francisco Bay area.

  17. A review of mosquitoes associated with Rift Valley fever virus in Madagascar.

    PubMed

    Tantely, Luciano M; Boyer, Sébastien; Fontenille, Didier

    2015-04-01

    Rift Valley fever (RVF) is a viral zoonotic disease occurring throughout Africa, the Arabian Peninsula, and Madagascar. The disease is caused by a Phlebovirus (RVF virus [RVFV]) transmitted to vertebrate hosts through the bite of infected mosquitoes. In Madagascar, the first RVFV circulation was reported in 1979 based on detection in mosquitoes but without epidemic episode. Subsequently, two outbreaks occurred: the first along the east coast and in the central highlands in 1990 and 1991 and the most recent along the northern and eastern coasts and in the central highlands in 2008 and 2009. Despite the presence of 24 mosquitoes species potentially associated with RVFV transmission in Madagascar, little associated entomological information is available. In this review, we list the RVFV vector, Culex antennatus, as well as other taxa as candidate vector species. We discuss risk factors from an entomological perspective for the re-emergence of RVF in Madagascar. PMID:25732680

  18. Mosquitoes (Diptera: Culicidae) in relation to the risk of disease transmission in El Ismailia Governorate, Egypt.

    PubMed

    Abdel-Hamid, Yousrya M; Soliman, Mohamed I; Kenawy, Mohamed A

    2011-08-01

    Mosquito were surveyed (Nov. 2009 - March 2010) in El Ismailia Governorate. Nine species were reported: Culex pipiens, Cx. perexiguus, Cx. antennatus, Anopheles tenebrosus, An. pharoensis, An. multicolor, Ochlerotatus detritus, Oc. caspius and Culiseta longiareolata. Culex pipiens was the predominant species (ca. 87% larvae and 57% adults). For the 3 common species, Cx. pipiens, Cx. perexiguus, and Cx. antennatus the following were examined: (1) the type and characteristics (temperature and pH) of the breeding habitats and their relation to the larval density and (2) the relation of adult indoor density to the indoor and outdoor temperature and RH. The abundance of mosquito vectors in El Ismailia with its old history of vector transmitted diseases contributes to the risk of mosquito borne disease transmission in this area. This would assist in the control activities. PMID:21980773

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

    PubMed Central

    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 mosquitoes from an outbreak-prone region, particularly with respect to one dengue strain. These findings suggest recent evolution of population-based differences in vector competence or different historical origins. Future genomic comparisons of these populations could reveal the genetic basis of vector competence and the relative role of selection and stochastic processes in shaping their differences. Lastly, we show the novel finding of a correlation between midgut dengue titer and titer in tissues colonized after dissemination. PMID:24420782

  20. Biodistribution and Trafficking of Hydrogel Nanoparticles in Adult Mosquitoes

    PubMed Central

    Paquette, Cynthia C. H.; Phanse, Yashdeep; Perry, Jillian L.; Sanchez-Vargas, Irma; Airs, Paul M.; Dunphy, Brendan M.; Xu, Jing; Carlson, Jonathan O.; Luft, J. Christopher; DeSimone, Joseph M.; Bartholomay, Lyric C.; Beaty, Barry J.

    2015-01-01

    Background Nanotechnology offers great potential for molecular genetic investigations and potential control of medically important arthropods. Major advances have been made in mammalian systems to define nanoparticle (NP) characteristics that condition trafficking and biodistribution of NPs in the host. Such information is critical for effective delivery of therapeutics and molecules to cells and organs, but little is known about biodistribution of NPs in mosquitoes. Methodology/Principal Findings PRINT technology was used to construct a library of fluorescently labeled hydrogel NPs of defined size, shape, and surface charge. The biodistribution (organ, tissue, and cell tropisms and trafficking kinetics) of positively and negatively charged 200 nm x 200 nm, 80 nm x 320 nm, and 80 nm x 5000 nm NPs was determined in adult Anopheles gambiae mosquitoes as a function of the route of challenge (ingestion, injection or contact) using whole body imaging and fluorescence microscopy. Mosquitoes readily ingested NPs in sugar solution. Whole body fluorescence imaging revealed substantial NP accumulation (load) in the alimentary tracts of the adult mosquitoes, with the greatest loads in the diverticula, cardia and foregut. Positively and negatively charged NPs differed in their biodistribution and trafficking. Following oral challenge, negatively charged NPs transited the alimentary tract more rapidly than positively charged NPs. Following contact challenge, negatively charged NPs trafficked more efficiently in alimentary tract tissues. Following parenteral challenge, positively and negatively charged NPs differed in tissue tropisms and trafficking in the hemocoel. Injected NPs were also detected in cardia/foregut, suggesting trafficking of NPs from the hemocoel into the alimentary tract. Conclusions/Significance Herein we have developed a tool box of NPs with the biodistribution and tissue tropism characteristics for gene structure/function studies and for delivery of vector lethal cargoes for mosquito control. PMID:25996505

  1. Three-way interactions between mosquito population, viral strain and temperature underlying chikungunya virus transmission potential.

    PubMed

    Zouache, Karima; Fontaine, Albin; Vega-Rua, Anubis; Mousson, Laurence; Thiberge, Jean-Michel; Lourenco-De-Oliveira, Ricardo; Caro, Valérie; Lambrechts, Louis; Failloux, Anna-Bella

    2014-10-01

    Interactions between pathogens and their insect vectors in nature are under the control of both genetic and non-genetic factors, yet most studies on mosquito vector competence for human pathogens are conducted in laboratory systems that do not consider genetic and/or environmental variability. Evaluating the risk of emergence of arthropod-borne viruses (arboviruses) of public health importance such as chikungunya virus (CHIKV) requires a more realistic appraisal of genetic and environmental contributions to vector competence. In particular, sources of variation do not necessarily act independently and may combine in the form of interactions. Here, we measured CHIKV transmission potential by the mosquito Aedes albopictus in all combinations of six worldwide vector populations, two virus strains and two ambient temperatures (20°C and 28°C). Overall, CHIKV transmission potential by Ae. albopictus strongly depended on the three-way combination of mosquito population, virus strain and temperature. Such genotype-by-genotype-by-environment (G × G × E) interactions question the relevance of vector competence studies conducted with a simpler set of conditions. Our results highlight the need to account for the complex interplay between vectors, pathogens and environmental factors to accurately assess the potential of vector-borne diseases to emerge. PMID:25122228

  2. Environmental management of mosquito-borne viruses in Rhode Island

    USGS Publications Warehouse

    Ginsberg, Howard S.; Gettman, Alan; Becker, Elisabeth; Bandyopadhyay, Ananda S.; LeBrun, Roger A.

    2013-01-01

    West Nile Virus (WNV) and Eastern Equine Encephalitis Virus (EEEV) are both primarily bird viruses, which can be transmitted by several mosquito species. Differences in larval habitats, flight, and biting patterns of the primary vector species result in substantial differences in epidemiology, with WNV more common, primarily occurring in urban areas, and EEEV relatively rare, typically occurring near swamp habitats. The complex transmission ecology of these viruses complicates prediction of disease outbreaks. The Rhode Island Department of Environmental Management (DEM) and Department of Health (DoH) provide prevention assistance to towns and maintain a mosquito surveillance program to identify potential disease risk. Responses to potential outbreaks follow a protocol based on surveillance results, assessment of human risk, and technical consultation.

  3. Mosquito Report for Jasper Ridge Biological Preserve

    E-print Network

    on the larval stage of mosquitoes, using environmentally sensitive materi- als. Control of larvae minimizes's Residence Portola Farms #12;Page 3 prevents mosquito larvae from de- veloping to adults. These materialsPage 1 Mosquito Report for Jasper Ridge Biological Preserve S a n M a t e o C o u n t y M o s q u i

  4. Interference between bunyaviruses in Aedes triseriatus mosquitoes.

    PubMed

    Beaty, B J; Bishop, D H; Gay, M; Fuller, F

    1983-05-01

    Inhibition of the replication of alternate California serogroup bunyaviruses in Aedes triseriatus mosquitoes has been observed for mosquitoes previously infected with La Crosse (LAC) virus. By contrast, prior infection of mosquitoes with LAC virus did not interfere significantly with the subsequent infection and replication of Guaroa bunyavirus (Bunyamwera serogroup), or heterologous viruses such as West Nile flavivirus, or vesicular stomatitis rhabdovirus. PMID:6305019

  5. Sugar-fermenting yeast as an organic source of carbon dioxide to attract the malaria mosquito Anopheles gambiae

    Microsoft Academic Search

    Renate C Smallegange; Wolfgang H Schmied; Karel J van Roey; Niels O Verhulst; Jeroen Spitzen; Wolfgang R Mukabana; Willem Takken

    2010-01-01

    BACKGROUND: Carbon dioxide (CO2) plays an important role in the host-seeking process of opportunistic, zoophilic and anthropophilic mosquito species and is, therefore, commonly added to mosquito sampling tools. The African malaria vector Anopheles gambiae sensu stricto is attracted to human volatiles augmented by CO2. This study investigated whether CO2, usually supplied from gas cylinders acquired from commercial industry, could be

  6. Identification and characterization of germline-specific promoters for remobilization of transgenes in the mosquitoes, Aedes aegypti and Anopheles gambiae

    E-print Network

    Hagen, Darren Erich

    2009-05-15

    .1. Defining the Problem ........................................................................ 1 1.1.1. Mosquito-borne pathogens.................................................... 1 1.1.2. Aedes aegypti, the Yellow Fever mosquito... vector for the pathogens that cause Yellow Fever and Dengue Fever. Ten to fifty million people contract Dengue Fever each year, leading to thousands of deaths. An additional 30,000 people die annually as a result of Yellow Fever (Centers for Disease...

  7. Artificial natural selection: can supplemental feeding domesticate mosquitoes and control mosquito-borne diseases?

    PubMed

    Egeth, Marc; Kurzban, Robert

    2012-01-01

    A new method is proposed for controlling mosquito-borne diseases. In particular, instead of trying to kill mosquitoes, we suggest provisioning them with food from artificial feeders. Because mosquito populations are frequently limited by ecological factors other than blood meals, such as the availability of egg-laying sites, feeding mosquitoes would not necessarily increase the total number of mosquitoes, but could reduce the number of human-drawn mosquito meals. Like mosquito traps, feeders could divert biting mosquitoes away from people by means of lures, but, after diversion, prevent subsequent human bites by satiating the mosquitoes instead of killing them. Mosquito feeders might reduce the problem of the evolution of resistance to control: in an ecology with mosquito feeders, which provide safe and abundant calories for adult female mosquitoes, there could be selection for preferring (rather than avoiding) feeders, which could eventually lead to a population of feeder-preferring mosquitoes. Artificial feeders also offer the chance to introduce novel elements into the mosquito diet, such as anti- malarial or other anti-parasitic agents. Feeders might directly reduce human bites and harnesses the power of natural selection by selectively favoring feeder-preferring (rather than trap-resistant) mosquitoes. PMID:22947681

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

    PubMed Central

    Dame, David A; Curtis, Christopher F; Benedict, Mark Q; Robinson, Alan S; Knols, Bart GJ

    2009-01-01

    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, aerial release technology and mass rearing. PMID:19917072

  9. Relationship between avian malaria distribution and an exotic invasive mosquito in New Zealand

    Microsoft Academic Search

    D. M. Tompkins; D. M. Gleeson

    2006-01-01

    Although the mosquito vector responsible for the epizootic outbreaks of avian malaria in Hawaiian avifauna, Culex quinquefasciatus, has spread rapidly in New Zealand over the past three decades, no survey for malarial parasites has been conducted for more than 50 years. Avian malaria often causes extreme morbidity and mortality in novel hosts, and much of New Zealand's native avifauna has

  10. Chemical ecology of the behaviour of the filariasis mosquito Culex quinquefasciatus Say

    Microsoft Academic Search

    L. E. G. Mboera

    1999-01-01

    Culex quinquefasciatus is an important vector of urban bancroftian filariasis in the tropical world. Despite its public health importance, much of its olfactory mediated behaviour is poorly understood. Studies on resource-location behaviour, in particular the role of semiochemicals in its behaviour, are required to understand the relationship between the mosquito, its host and the surrounding environment to effectively control bancroftian

  11. Serological classification of Bacillus sphaericus strains on the basis of toxicity to mosquito larvae

    Microsoft Academic Search

    H. de Barjac; I. Larget-Thiéry; V. Cosmao Dumanoir; H. Ripouteau

    1985-01-01

    A toxicity study of 54 Bacillus sphaericus strains isolated from vectors or breeding sites has led to a relatively homogeneous grouping of mosquito pathogenic strains into five H-serotypes among the nine serotypes determined. Each serotype seems to be characterized by a different level of toxicity and a classification of these five serotypes can be made on the basis of this

  12. Spatial Distribution of Mosquito Larvae and the Potential for Targeted Larval Control in The Gambia

    Microsoft Academic Search

    Silas Majambere; Ulrike Fillinger; David R. Sayer; Clare Green; Steven W. Lindsay

    2008-01-01

    We examined the distribution of aquatic stages of malaria vectors in a 400-km2 area in rural Gambia to assess the practicality of targeting larval control. During the rainy season, the peak period of malaria transmission, breeding sites were 70% more likely to have anopheline larvae in the floodplain of the Gambia River than upland sites (P < 0.001). However, mosquitoes

  13. Michelob_x is the missing inhibitor of apoptosis protein antagonist in mosquito genomes

    Microsoft Academic Search

    Guohua Jiang; Gina Chan; Carl P Santos; David W Severson; Lei Xiao; Lei Zhou

    2005-01-01

    Apoptosis is implicated in the life cycle of the malaria parasite in mosquitoes. The genome project for the primary malaria vector Anopheles gambiae showed a significant expansion of the inhibitor of apoptosis protein (IAP) and caspase gene families in comparison with Drosophila. However, because of extensive sequence divergence, no orthologue was identified for the reaper\\/grim-like IAP antagonist genes that have

  14. Chikungunya virus adapts to tiger mosquito via evolutionary convergence: a sign of things to come?

    Microsoft Academic Search

    Xavier de Lamballerie; Eric Leroy; Rémi N Charrel; Konstantin Ttsetsarkin; Stephen Higgs; Ernest A Gould

    2008-01-01

    Since 2004, several million indigenous cases of Chikungunya virus disease occurred in Africa, the Indian Ocean, India, Asia and, recently, Europe. The virus, usually transmitted by Aedes aegypti mosquitoes, has now repeatedly been associated with a new vector, Ae. Albopictus. Analysis of full-length viral sequences reveals three independent events of virus exposure to Ae. Albopictus, each followed by the acquisition

  15. West Nile Virus Epidemics in North America Are Driven by Shifts in Mosquito Feeding Behavior

    Microsoft Academic Search

    A. Marm Kilpatrick; Laura D. Kramer; Matthew J. Jones; Peter P. Marra; Peter Daszak

    2006-01-01

    West Nile virus (WNV) has caused repeated large-scale human epidemics in North America since it was first detected in 1999 and is now the dominant vector-borne disease in this continent. Understanding the factors that determine the intensity of the spillover of this zoonotic pathogen from birds to humans (via mosquitoes) is a prerequisite for predicting and preventing human epidemics. We

  16. West Nile Virus Epidemics in North America Are Driven by Shifts in Mosquito Feeding

    Microsoft Academic Search

    Laura D. Kramer; Matthew J. Jones; Peter P. Marra; Peter Daszak

    2006-01-01

    West Nile virus (WNV) has caused repeated large-scale human epidemics in North America since it was first detected in 1999 and is now the dominant vector-borne disease in this continent. Understanding the factors that determine the intensity of the spillover of this zoonotic pathogen from birds to humans (via mosquitoes) is a prerequisite for predicting and preventing human epidemics. We

  17. Olfaction in the malaria mosquito Anopheles gambiae : Electrophysiology and identification of kairomones

    Microsoft Academic Search

    J. Meijerink

    1999-01-01

    Female mosquitoes of the species Anopheles gambiae Giles sensu stricto are important vectors of human malaria in Africa. It is generally assumed that they locate their human host by odours. These odours are detected by olfactory receptor neurons situated within cuticular extensions on the antenna. These cuticular extensions, called sensilla, contain numerous pores through which the odours can enter the

  18. Stable Transformation of the Yellow Fever Mosquito, Aedes aegypti, with the Hermes Element from the Housefly

    Microsoft Academic Search

    Nijole Jasinskiene; Craig J. Coates; Mark Q. Benedict; Anthony J. Cornel; Cristina Salazar Rafferty; Anthony A. James; Frank H. Collins

    1998-01-01

    The mosquito Aedes aegypti is the world's most important vector of yellow fever and dengue viruses. Work is currently in progress to control the transmission of these viruses by genetically altering the capacity of wild Ae. aegypti populations to support virus replication. The germline transformation system reported here constitutes a major advance toward the implementation of this control strategy. A

  19. An Ecological Risk Assessment for Insecticides Used in Adult Mosquito Management

    Microsoft Academic Search

    Ryan S Davis; Robert KD Peterson

    2007-01-01

    West Nile virus (WNV) has been a concern for people across the United States since the disease was initially observed in the summer of 1999. Since 1999, WNV has caused the largest arboviral encephalitis epidemic in US history. Vector control management programs have been intensively implemented to control mosquitoes that carry WNV. Our deterministic ecological risk assessment focused on 6

  20. Short Report: The effect of preservation methods on predicting mosquito age by near-infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determining mosquito age is important to evaluate vector control programs because the ability to transmit diseases is age-dependent. Current age-grading techniques require dissection or DNA extraction. Near-infrared spectroscopy has been used to rapidly and nondestructively determine the age of fr...

  1. A dynamic model of some malaria-transmitting anopheline mosquitoes of the Afrotropical region. I. Model description and sensitivity analysis

    PubMed Central

    2013-01-01

    Background Most of the current biophysical models designed to address the large-scale distribution of malaria assume that transmission of the disease is independent of the vector involved. Another common assumption in these type of model is that the mortality rate of mosquitoes is constant over their life span and that their dispersion is negligible. Mosquito models are important in the prediction of malaria and hence there is a need for a realistic representation of the vectors involved. Results We construct a biophysical model including two competing species, Anopheles gambiae s.s. and Anopheles arabiensis. Sensitivity analysis highlight the importance of relative humidity and mosquito size, the initial conditions and dispersion, and a rarely used parameter, the probability of finding blood. We also show that the assumption of exponential mortality of adult mosquitoes does not match the observed data, and suggest that an age dimension can overcome this problem. Conclusions This study highlights some of the assumptions commonly used when constructing mosquito-malaria models and presents a realistic model of An. gambiae s.s. and An. arabiensis and their interaction. This new mosquito model, OMaWa, can improve our understanding of the dynamics of these vectors, which in turn can be used to understand the dynamics of malaria. PMID:23342980

  2. Entomological indices, feeding sources, and molecular identification of Triatoma phyllosoma (Hemiptera: Reduviidae) one of the main vectors of Chagas disease in the Istmo de Tehuantepec, Oaxaca, Mexico.

    PubMed

    Villalobos, Guiehdani; Martínez-Hernández, Fernando; de la Torre, Patricia; Laclette, Juan Pedro; Espinoza, Bertha

    2011-09-01

    The purpose of this study was to conduct an entomological analysis, determination of feeding sources, and molecular identification of triatomines in five communities of the Istmo de Tehuantepec, Oaxaca. The only found species in two of five searched communities (San Mateo del Mar and Tehuantepec City) was Triatoma phyllosoma. Colonization indices were high in both communities. In San Mateo del Mar, the insects were found indoors and in Tehuantepec City in peridomestic areas. The Trypanosoma cruzi infection indices were 2.1% in San Mateo del Mar and 39.4% in Tehuantepec City. This difference could be related to the high numbers of triatomine feeding on hens in the former community. In contrast, in Tehuantepec, dogs were the principal triatomine feeding sources. All nymphs and adults that were genetically analyzed belonged to the species T. phyllosoma. Low levels of genetic variation were found between vectors from both communities. PMID:21896810

  3. Importance of endogenous feedback controlling the long-term abundance of tropical mosquito species

    Microsoft Academic Search

    Guo-Jing Yang; Corey J. A. Bradshaw; Peter I. Whelan; Barry W. Brook

    2008-01-01

    Mosquitoes are a major vector for tropical diseases, so understanding aspects that modify their population dynamics is vital\\u000a for their control and protecting human health. Maximising the efficiency of control strategies for reducing transmission risk\\u000a requires as a first step the understanding of the intrinsic population dynamics of vectors. We fitted a set of density-dependent\\u000a and density-independent models to the

  4. Field Testing of Different Chemical Combinations as Odour Baits for Trapping Wild Mosquitoes in The Gambia

    Microsoft Academic Search

    Musa Jawara; Taiwo S. Awolola; Margaret Pinder; David Jeffries; Renate C. Smallegange; Willem Takken; David J. Conway; Nirbhay Kumar

    2011-01-01

    Odour baited traps have potential use in population surveillance of insect vectors of disease, and in some cases for vector population reduction. Established attractants for human host-seeking mosquitoes include a combination of CO2 with L-lactic acid and ammonia, on top of which additional candidate compounds are being tested. In this field study in rural Gambia, using Latin square experiments with

  5. Deprivation of both sucrose and water reduces the mosquito heart contraction rate while increasing the expression of nitric oxide synthase.

    PubMed

    Ellison, Haley E; Estévez-Lao, Tania Y; Murphree, C Steven; Hillyer, Julián F

    2015-03-01

    Adult female mosquitoes rely on carbohydrate-rich plant nectars as their main source of energy. In the present study we tested whether the deprivation of a carbohydrate dietary source or the deprivation of both carbohydrate and water affects mosquito heart physiology. Intravital video imaging of Anopheles gambiae showed that, relative to sucrose fed mosquitoes, the deprivation of both sucrose and water for 24h, but not the deprivation of sucrose alone, reduces the heart contraction rate. Measurement of the protein, carbohydrate and lipid content of mosquitoes in the three treatment groups did not explain this cardiac phenotype. However, while the deprivation of sucrose reduced mosquito weight and abdominal width, the deprivation of both sucrose and water reduced mosquito weight even further without augmenting the change in abdominal width, indirectly suggesting that starvation and dehydration reduces hemolymph pressure. Analysis of the mRNA levels of crustacean cardioactive peptide (CCAP), FMRFamide, corazonin, neuropeptide F and short neuropeptide F then suggested that these neuropeptides do not regulate the cardiac phenotype observed. However, relative to sucrose fed and sucrose deprived mosquitoes, the mRNA level of nitric oxide synthase (NOS) was significantly elevated in mosquitoes that had been deprived of both sucrose and water. Given that nitric oxide suppresses the heart rate of vertebrates and invertebrates, these data suggest a role for this free radical in modulating mosquito heart physiology. PMID:25640058

  6. Colonization of abandoned swimming pools by larval mosquitoes and their predators following Hurricane Katrina.

    PubMed

    Caillouët, Kevin A; Carlson, John C; Wesson, Dawn; Jordan, Frank

    2008-06-01

    Thousands of flooded swimming pools were abandoned in New Orleans following Hurricane Katrina and provided a natural experiment to examine colonization of a novel aquatic habitat by mosquito larvae and their aquatic predators. We conducted a randomized survey of flooded swimming pools in two neighborhoods in January 2006 and found that 64% contained mosquito larvae, 92% contained predatory invertebrates, and 47% contained fishes. We collected 12,379 immature mosquitoes representing five species, primarily Culiseta inornata, and secondarily, the arboviral vector Culex quinquefasciatus. Dragonfly nymphs in the families Aeshnidae and Libellulidae were the most common predatory invertebrates collected among a total of 32 non-mosquito invertebrate species. Eleven species of fishes were collected, with Gambusia affinis accounting for 76% of the catch. Diversity of fishes in swimming pools was positively correlated with proximity to a levee breach and the fish assemblage found in swimming pools was similar to that found along shorelines of Lake Pontchartrain and drainage canals that flooded the study area. Mosquito larvae were rare or absent from pools containing fishes; however, path analysis indicated that the presence of top predators or abundant competitors may somewhat mitigate the effect of Gambusia affinis on mosquito presence. PMID:18697320

  7. A Metagenomic Survey of Viral Abundance and Diversity in Mosquitoes from Hubei Province

    PubMed Central

    Shi, Chenyan; Liu, Yi; Hu, Xiaomin; Xiong, Jinfeng; Zhang, Bo; Yuan, Zhiming

    2015-01-01

    Mosquitoes as one of the most common but important vectors have the potential to transmit or acquire a lot of viruses through biting, however viral flora in mosquitoes and its impact on mosquito-borne disease transmission has not been well investigated and evaluated. In this study, the metagenomic techniquehas been successfully employed in analyzing the abundance and diversity of viral community in three mosquito samples from Hubei, China. Among 92,304 reads produced through a run with 454 GS FLX system, 39% have high similarities with viral sequences belonging to identified bacterial, fungal, animal, plant and insect viruses, and 0.02% were classed into unidentified viral sequences, demonstrating high abundance and diversity of viruses in mosquitoes. Furthermore, two novel viruses in subfamily Densovirinae and family Dicistroviridae were identified, and six torque tenosus virus1 in family Anelloviridae, three porcine parvoviruses in subfamily Parvovirinae and a Culex tritaeniorhynchus rhabdovirus in Family Rhabdoviridae were preliminarily characterized. The viral metagenomic analysis offered us a deep insight into the viral population of mosquito which played an important role in viral initiative or passive transmission and evolution during the process. PMID:26030271

  8. Insecticide-treated vertical mesh barriers reduce the number of biting mosquitoes.

    PubMed

    Faiman, R; Warburg, A

    2012-03-01

    Mosquitoes foraging for blood sources normally fly relatively close to the ground where wind velocities do not exceed their flight speed. An experiment designed to block foraging mosquitoes from reaching inhabited houses was conducted in a rural settlement flanked by agricultural fields. Mosquitoes were collected during 9 nights using 30 carbon dioxide-baited traps deployed along the external walls of six houses in the row closest to the settlement's perimeter fence. Thereafter, a deltamethrin-impregnated mesh was draped along 400 m of the perimeter fence to a height of 2 m opposite three of the monitored houses. Mosquitoes were trapped for a further 11 nights. A significant difference in the numbers of mosquitoes caught before and after the intervention was demonstrated near protected houses, whereas no significant difference was observed in catches near control houses. The percentage of Culex perexiguus (Diptera: Culicidae), an important vector of West Nile virus, was significantly lower near protected houses (13%) than around control houses (45%). By contrast, the percentage of Culex pipiens was not significantly affected (16% at experimental and 18% at control houses). Although the results presented here are preliminary, the data demonstrate the potential efficacy of vertical insecticidal barriers for mosquito control. PMID:21615442

  9. Injury and immune response: applying the danger theory to mosquitoes

    PubMed Central

    Moreno-García, Miguel; Recio-Tótoro, Benito; Claudio-Piedras, Fabiola; Lanz-Mendoza, Humberto

    2014-01-01

    The insect immune response can be activated by the recognition of both non-self and molecular by-products of tissue damage. Since pathogens and tissue damage usually arise at the same time during infection, the specific mechanisms of the immune response to microorganisms, and to tissue damage have not been unraveled. Consequently, some aspects of damage caused by microorganisms in vector-borne arthropods have been neglected. We herein reassess the Anopheles–Plasmodium interaction, incorporating Matzinger’s danger/damage hypothesis and George Salt’s injury assumptions. The invasive forms of the parasite cross the peritrophic matrix and midgut epithelia to reach the basal lamina and differentiate into an oocyst. The sporozoites produced in the oocyst are released into the hemolymph, and from there enter the salivary gland. During parasite development, wounds to midgut tissue and the basement membrane are produced. We describe the response of the different compartments where the parasite interacts with the mosquito. In the midgut, the response includes the expression of antimicrobial peptides, production of reactive oxygen species, and possible activation of midgut regenerative cells. In the basal membrane, wound repair mainly involves the production of molecules and the recruitment of hemocytes. We discuss the susceptibility to damage in tissues, and how the place and degree of damage may influence the differential response and the expression of damage associated molecular patterns (DAMPs). Knowledge about damage caused by parasites may lead to a deeper understanding of the relevance of tissue damage and the immune response it generates, as well as the origins and progression of infection in this insect–parasite interaction. PMID:25250040

  10. Field assessment of yeast- and oxalic Acid-generated carbon dioxide for mosquito surveillance.

    PubMed

    Harwood, James F; Richardson, Alec G; Wright, Jennifer A; Obenauer, Peter J

    2014-12-01

    Carbon dioxide (CO2) sources improve the efficacy of mosquito traps. However, traditional CO2 sources (dry ice or compressed gas) may be difficult to acquire for vector surveillance during military contingency operations. For this reason, a new and convenient source of CO2 is required. Two novel CO2 generators were evaluated in order to address this capability gap: 1) an electrolyzer that converts solid oxalic acid into CO2 gas, and 2) CO2 produced by yeast as it metabolizes sugar. The flow rate and CO2 concentration produced by each generator were measured, and each generator's ability to attract mosquitoes to BG-Sentinel™ traps during day surveillance and to Centers for Disease Control and Prevention light traps with incandescent bulbs during night surveillance was compared to dry ice and compressed gas in Jacksonville, FL. The electrolyzed oxalic acid only slightly increased the number of mosquitoes captured compared to unbaited traps. Based on the modest increase in mosquito collection for traps paired with the oxalic acid, it is not a suitable stand-in for either of the 2 traditional CO2 sources. Conversely, the yeast-generated CO2 resulted in collections with mosquito abundance and species richness more closely resembling those of the traditional CO2 sources, despite achieving a lower CO2 flow rate. Therefore, if dry ice or compressed gas cannot be acquired for vector surveillance, yeast-generated CO2 can significantly improve trap capability. PMID:25843133

  11. Novel Genetic and Molecular Tools for the Investigation and Control of Dengue Virus Transmission by Mosquitoes.

    PubMed

    Franz, Alexander W E; Clem, Rollie J; Passarelli, A Lorena

    2014-03-01

    Aedes aegypti is the principal vector of dengue virus (DENV) throughout the tropical world. This anthropophilic mosquito species needs to be persistently infected with DENV before it can transmit the virus through its saliva to a new vertebrate host. In the mosquito, DENV is confronted with several innate immune pathways, among which RNA interference is considered the most important. The Ae. aegypti genome project opened the doors for advanced molecular studies on pathogen-vector interactions including genetic manipulation of the vector for basic research and vector control purposes. Thus, Ae. aegypti has become the primary model for studying vector competence for arboviruses at the molecular level. Here, we present recent findings regarding DENV-mosquito interactions, emphasizing how innate immune responses modulate DENV infections in Ae. aegypti. We also describe the latest advancements in genetic manipulation of Ae. aegypti and discuss how this technology can be used to investigate vector transmission of DENV at the molecular level and to control transmission of the virus in the field. PMID:24693489

  12. Innate immunity in the malaria vector Anopheles gambiae: comparative and functional genomics.

    PubMed

    Osta, Mike A; Christophides, George K; Vlachou, Dina; Kafatos, Fotis C

    2004-07-01

    The resurgence of malaria is at least partly attributed to the absence of an effective vaccine, parasite resistance to antimalarial drugs and resistance to insecticides of the anopheline mosquito vectors. Novel strategies are needed to combat the disease on three fronts: protection (vaccines), prophylaxis/treatment (antimalarial drugs) and transmission blocking. The latter entails either killing the mosquitoes (insecticides), preventing mosquito biting (bednets and repellents), blocking parasite development in the vector (transmission blocking vaccines), genetic manipulation or chemical incapacitation of the vector. During the past decade, mosquito research has been energized by several breakthroughs, including the successful transformation of anopheline vectors, analysis of gene function by RNAi, genome-wide expression profiling using DNA microarrays and, most importantly, sequencing of the Anopheles gambiae genome. These breakthroughs helped unravel some of the mechanisms underlying the dynamic interactions between the parasite and the vector and shed light on the mosquito innate immune system as a set of potential targets to block parasite development. In this context, putative pattern recognition receptors of the mosquito that act as positive and negative regulators of parasite development have been identified recently. Characterizing these molecules and others of similar function, and identifying their ligands on the parasite surface, will provide clues on the nature of the interactions that define an efficient parasite-vector system and open up unprecedented opportunities to control the vectorial capacity of anopheline mosquitoes. PMID:15201288

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

    PubMed Central

    Phuc, Hoang Kim; Andreasen, Morten H; Burton, Rosemary S; Vass, Céline; Epton, Matthew J; Pape, Gavin; Fu, Guoliang; Condon, Kirsty C; Scaife, Sarah; Donnelly, Christl A; Coleman, Paul G; White-Cooper, Helen; Alphey, Luke

    2007-01-01

    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 improved SIT for disease control. PMID:17374148

  14. Natural Plant Sugar Sources of Anopheles Mosquitoes Strongly Impact Malaria Transmission Potential

    PubMed Central

    Gu, Weidong; Müller, Günter; Schlein, Yosef; Novak, Robert J.; Beier, John C.

    2011-01-01

    An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595), lower survival rates (0.72 vs. 0.93), and prolonged gonotrophic cycles (3.33 vs. 2.36 days). The estimated number of females older than the extrinsic incubation period of malaria (10 days) in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73%) than in the sugar-poor site (48%). In contrast, plant tissue feeding (poor quality sugar source) in the sugar-rich habitat was much less (0.3%) than in the sugar-poor site (30%). More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens. PMID:21283732

  15. Comparative susceptibility to permethrin of two Anopheles gambiae s.l. populations from Southern Benin, regarding mosquito sex, physiological status, and mosquito age

    PubMed Central

    Aïzoun, Nazaire; Aïkpon, Rock; Azondekon, Roseric; Asidi, Alex; Akogbéto, Martin

    2014-01-01

    Objective To investigate what kind of mosquito sample is necessary for the determination of insecticide susceptibility in malaria vectors. Methods Larvae and pupae of Anopheles gambiae s.l. (An. gambiae) mosquitoes were collected from the breeding sites in Littoral and Oueme departments. The Centers for Disease Control and Prevention (CDC) susceptibility tests were conducted on unfed male and female mosquitoes aged 2-5 days old. CDC susceptibility tests were also conducted on unfed, blood fed and gravid female mosquitoes aged 2-5 days old. These susceptibility tests were also conducted on unfed and blood fed female mosquitoes aged 2-5 days old and 20 days old. CDC biochemical assay using synergist was also carried out to detect any increase in the activity of enzyme typically involved in insecticide metabolism. Results Female An. gambiae Ladji and Sekandji populations were more susceptible than the males when they were unfed and aged 2-5 days old. The mortality rates of blood fed female An. gambiae Ladji and Sekandji populations aged 2-5 days old were lower than those obtained when females were unfed. In addition, the mortality rates of gravid female An. gambiae Ladji and Sekandji populations aged 2-5 days old were lower than those obtained when they were unfed. The mortality rate obtained when female An. gambiae Sekandji populations were unfed and aged 20 days old was higher than the one obtained when these populations were unfed and aged 2-5 days old. The results obtained after effects of synergist penicillin in beeswax on F1 progeny of An. gambiae Ladji populations resistant to permethrin showed that mono-oxygenases were involved in permethrin resistant F1 progeny from Ladji. Conclusions The resistance is a hereditary and dynamic phenomenon which can be due to metabolic mechanisms like overproduction of detoxifying enzymes activity. Many factors influence vector susceptibility to insecticide. Among these factors, there are mosquito sex, mosquito age, its physiological status. Therefore, it is useful to respect the World Health Organization criteria in the assessment of insecticide susceptibility tests in malaria vectors. Otherwise, susceptibility testing is conducted using unfed female mosquitoes aged 3-5 days old. Tests should also be carried out at (25±2) °C and (80±10)% relative humidity. PMID:25182557

  16. A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies

    PubMed Central

    2012-01-01

    Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words “Mosquito coils” “Mosquito emanators” and “Spatial repellents”. It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose–response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control. PMID:23216844

  17. Arm-in-cage testing of natural human-derived mosquito repellents

    PubMed Central

    2010-01-01

    Background Individual human subjects are differentially attractive to mosquitoes and other biting insects. Previous investigations have demonstrated that this can be attributed partly to enhanced production of natural repellent chemicals by those individuals that attract few mosquitoes in the laboratory. The most important compounds in this respect include three aldehydes, octanal, nonanal and decanal, and two ketones, 6-methyl-5-hepten-2-one and geranylacetone [(E)-6,10-dimethylundeca-5,9-dien-2-one]. In olfactometer trials, these compounds interfered with attraction of mosquitoes to a host and consequently show promise as novel mosquito repellents. Methods To test whether these chemicals could provide protection against mosquitoes, laboratory repellency trials were carried out to test the chemicals individually at different concentrations and in different mixtures and ratios with three major disease vectors: Anopheles gambiae, Culex quinquefasciatus and Aedes aegypti. Results Up to 100% repellency was achieved depending on the type of repellent compound tested, the concentration and the relative composition of the mixture. The greatest effect was observed by mixing together two compounds, 6-methyl-5-hepten-2-one and geranylacetone in a 1:1 ratio. This mixture exceeded the repellency of DEET when presented at low concentrations. The repellent effect of this mixture was maintained over several hours. Altering the ratio of these compounds significantly affected the behavioural response of the mosquitoes, providing evidence for the ability of mosquitoes to detect and respond to specific mixtures and ratios of natural repellent compounds that are associated with host location. Conclusion The optimum mixture of 6-methyl-5-hepten-2-one and geranylacetone was a 1:1 ratio and this provided the most effective protection against all species of mosquito tested. With further improvements in formulation, selected blends of these compounds have the potential to be exploited and developed as human-derived novel repellents for personal protection. PMID:20727149

  18. PCR detection of malaria parasites in desiccated Anopheles mosquitoes is uninhibited by storage time and temperature

    PubMed Central

    2012-01-01

    Background Reliable methods to preserve mosquito vectors for malaria studies are necessary for detecting Plasmodium parasites. In field settings, however, maintaining a cold chain of storage from the time of collection until laboratory processing, or accessing other reliable means of sample preservation is often logistically impractical or cost prohibitive. As the Plasmodium infection rate of Anopheles mosquitoes is a central component of the entomological inoculation rate and other indicators of transmission intensity, storage conditions that affect pathogen detection may bias malaria surveillance indicators. This study investigated the effect of storage time and temperature on the ability to detect Plasmodium parasites in desiccated Anopheles mosquitoes by real-time polymerase chain reaction (PCR). Methods Laboratory-infected Anopheles stephensi mosquitoes were chloroform-killed and stored over desiccant for 0, 1, 3, and 6 months while being held at four different temperatures: 28, 37, -20 and -80°C. The detection of Plasmodium DNA was evaluated by real-time PCR amplification of a 111 base pair region of block 4 of the merozoite surface protein. Results Varying the storage time and temperature of desiccated mosquitoes did not impact the sensitivity of parasite detection. A two-way factorial analysis of variance suggested that storage time and temperature were not associated with a loss in the ability to detect parasites. Storage of samples at 28°C resulted in a significant increase in the ability to detect parasite DNA, though no other positive associations were observed between the experimental storage treatments and PCR amplification. Conclusions Cold chain maintenance of desiccated mosquito samples is not necessary for real-time PCR detection of parasite DNA. Though field-collected mosquitoes may be subjected to variable conditions prior to molecular processing, the storage of samples over an inexpensive and logistically accessible desiccant will likely ensure accurate assessment of malaria parasite presence without diminishing PCR-detection of parasites in mosquitoes stored for at least six months. PMID:22682161

  19. Risk of canine and human exposure to Dirofilaria immitis infected mosquitoes in endemic areas of Italy

    PubMed Central

    2013-01-01

    Background The occurrence of infections by Dirofilaria immitis in canine and human populations depends on several factors linked to both the definitive and intermediate hosts. Little data are available on the risk of human and dog exposure to D. immitis in endemic areas. Data collected on dog- and human-bait traps in endemic areas of north-eastern Italy were used to estimate the likelihood of a receptive host coming into contact with an infected vector. Methods From 1997 to 1999, mosquitoes were collected from three sampling sites of north-eastern Italy on D. immitis microfilaraemic dogs and on human baits. The bite/night/host rates were determined based on the number of feeding and probing mosquitoes on dogs and humans, respectively. The survival/mortality rates of different species of mosquitoes following the blood meal, and the rate of natural Dirofilaria infection in unfed specimens were estimated. The risk of exposure of dogs and humans to infected mosquito species was determined by combining the bite/host/night and the mosquito infection rates. Results A total of 1,165 mosquitoes were collected on human (n?=?815) and dog (n?=?350) baits with varying species composition (i.e., Culex pipiens, 87.3% and Ochlerotatus caspius, 11.6%). Overall, dogs were more attractive to Cx pipiens than humans (feeding rate 70.2% vs probing rate 25.9%). The highest bite/night/host rate was 84.0 for dogs and 26.5 for humans. Cx pipiens displayed a mortality rate of 76.3% within 13 days and Oc. caspius of 100% within two days following the infective blood meal. In addition, D. immitis DNA was detected in unfed Cx pipiens (infection rate of 0.26%-2.07%). The infection rate adjusted for mosquito mortality was 0.38%. Based on data collected, the contact between an infected mosquito and a host can occur as often as every four nights for D. immitis infected-mosquitoes in dogs and within two weeks for humans. Conclusions Cx pipiens was confirmed as the most efficient natural vector of D. immitis in the studied area. In endemic areas, the risk of transmission can be very high for dogs and relevant for humans. Despite the increased awareness of veterinarians and owners on canine dirofilarioses, dogs from rural areas still maintain the natural life cycle of Dirofilaria spp., therefore acting as a source of infection to humans through vector bites. PMID:23510597

  20. Genetic Mapping of Specific Interactions between Aedes aegypti Mosquitoes and Dengue Viruses

    PubMed Central

    Diancourt, Laure; Caro, Valérie; Thaisomboonsuk, Butsaya; Richardson, Jason H.; Jarman, Richard G.; Ponlawat, Alongkot; Lambrechts, Louis

    2013-01-01

    Specific interactions between host genotypes and pathogen genotypes (G×G interactions) are commonly observed in invertebrate systems. Such specificity challenges our current understanding of invertebrate defenses against pathogens because it contrasts the limited discriminatory power of known invertebrate immune responses. Lack of a mechanistic explanation, however, has questioned the nature of host factors underlying G×G interactions. In this study, we aimed to determine whether G×G interactions observed between dengue viruses and their Aedes aegypti vectors in nature can be mapped to discrete loci in the mosquito genome and to document their genetic architecture. We developed an innovative genetic mapping strategy to survey G×G interactions using outbred mosquito families that were experimentally exposed to genetically distinct isolates of two dengue virus serotypes derived from human patients. Genetic loci associated with vector competence indices were detected in multiple regions of the mosquito genome. Importantly, correlation between genotype and phenotype was virus isolate-specific at several of these loci, indicating G×G interactions. The relatively high percentage of phenotypic variation explained by the markers associated with G×G interactions (ranging from 7.8% to 16.5%) is consistent with large-effect host genetic factors. Our data demonstrate that G×G interactions between dengue viruses and mosquito vectors can be assigned to physical regions of the mosquito genome, some of which have a large effect on the phenotype. This finding establishes the existence of tangible host genetic factors underlying specific interactions between invertebrates and their pathogens in a natural system. Fine mapping of the uncovered genetic loci will elucidate the molecular mechanisms of mosquito-virus specificity. PMID:23935524

  1. Molecular detection of Setaria tundra (Nematoda: Filarioidea) and an unidentified filarial species in mosquitoes in Germany

    PubMed Central

    2012-01-01

    Background Knowledge of the potential vector role of Culicidae mosquitoes in Germany is very scanty, and until recently it was generally assumed that they are not involved in the transmission of anthroponotic or zoonotic pathogens in this country. However, anticipated changes in the course of global warming and globalization may alter their status. Methods We conducted a molecular mass screening of mosquitoes for filarial parasites using mitochondrial 12S rRNA-based real-time PCR. Results No parasites causing disease in humans such as Dirofilaria spp. were detected in about 83,000 mosquitoes tested, which had been collected in 2009 and 2010 in 16 locations throughout Germany. However, minimum infection rates of up to 24 per 1000 mosquitoes were revealed, which could be attributed to mosquito infection with Setaria tundra and a yet unidentified second parasite. Setaria tundra was found to be widespread in southern Germany in various mosquito species, except Culex spp. In contrast, the unidentified filarial species was exclusively found in Culex spp. in northern Baden-Württemberg, and is likely to be a bird parasite. Conclusions Although dirofilariasis appears to be emerging and spreading in Europe, the absence of Dirofilaria spp. or other zoonotic filariae in our sample allows the conclusion that the risk of autochthonous infection in Germany is still very low. Potential vectors of S. tundra in Germany are Ochlerotatus sticticus, Oc. cantans, Aedes vexans and Anopheles claviger. Technically, the synergism between entomologists, virologists and parasitologists, combined with state-of-the-art methods allows a very efficient near-real-time monitoring of a wide spectrum of both human and veterinary pathogens, including new distribution records of parasite species and the incrimination of their potential vectors. PMID:22236560

  2. CONTRIBUTIONS OF INVERTEBRATE PATHOLOGY TO VECTOR CONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control of the invertebrate host is an integral part of any integrated program to prevent the spread of vector borne diseases of man and animals. This includes important mosquito borne arboviruses such as yellow fever, dengue and the various types of encephalitis including West Nile Virus, St. Loui...

  3. Mosquitoes meet microfluidics: High-throughput microfluidic tools for insect-parasite ecology in field conditions

    NASA Astrophysics Data System (ADS)

    Prakash, Manu; Mukundarajan, Haripriya

    2013-11-01

    A simple bite from an insect is the transmission mechanism for many deadly diseases worldwide--including malaria, yellow fever, west nile and dengue. Very little is known about how populations of numerous insect species and disease-causing parasites interact in their natural habitats due to a lack of measurement techniques. At present, vector surveillance techniques involve manual capture by using humans as live bait, which is hard to justify on ethical grounds. Individual mosquitoes are manually dissected to isolate salivary glands to detect sporozites. With typical vector infection rates being very low even in endemic areas, it is almost impossible to get an accurate picture of disease distribution, in both space and time. Here we present novel high-throughput microfluidic tools for vector surveillance, specifically mosquitoes. A two-dimensional high density array with baits provide an integrated platform for multiplex PCR for detection of both vector and parasite species. Combining techniques from engineering and field ecology, methods and tools developed here will enable high-throughput measurement of infection rates for a number of diseases in mosquito populations in field conditions. A simple bite from an insect is the transmission mechanism for many deadly diseases worldwide--including malaria, yellow fever, west nile and dengue. Very little is known about how populations of numerous insect species and disease-causing parasites interact in their natural habitats due to a lack of measurement techniques. At present, vector surveillance techniques involve manual capture by using humans as live bait, which is hard to justify on ethical grounds. Individual mosquitoes are manually dissected to isolate salivary glands to detect sporozites. With typical vector infection rates being very low even in endemic areas, it is almost impossible to get an accurate picture of disease distribution, in both space and time. Here we present novel high-throughput microfluidic tools for vector surveillance, specifically mosquitoes. A two-dimensional high density array with baits provide an integrated platform for multiplex PCR for detection of both vector and parasite species. Combining techniques from engineering and field ecology, methods and tools developed here will enable high-throughput measurement of infection rates for a number of diseases in mosquito populations in field conditions. Pew Foundation.

  4. Impacts of climate, land use, and biological invasion on the ecology of immature Aedes mosquitoes: Implications for La Crosse emergence

    PubMed Central

    Leisnham, Paul; Juliano, Steven A.

    2012-01-01

    Arthropod-borne viruses (arboviruses) cause many diseases worldwide and their transmission is likely to change with land use and climate changes. La Crosse virus is historically transmitted by the native mosquito Aedes triseriatus (Say) in the upper Midwestern U.S., but the invasive congeners Aedes albopictus (Skuse) and Aedes japonicus (Theobald), which co-occur with A. triseriatus in water-holding containers, may be important accessory vectors in the Appalachian region where La Crosse encephalitis is an emerging disease. This review focuses on evidence for how climate, land use, and biological invasions may have direct abiotic and indirect community-level impacts on immature developmental stages (eggs and larvae) of Aedes mosquitoes. Because vector-borne diseases usually vary in space and time and are related to the ecology of the vector species, we propose that the ecology of its mosquito vectors, particularly at their immature stages, has played an important role in the emergence of La Crosse encephalitis in the Appalachian region and represents a model for investigating the effects of environmental changes on other vector-borne diseases. We summarize the health effects of La Crosse virus and associated socioeconomic costs that make it the most important native mosquito-borne disease in the U.S. We review of the transmission of La Crosse virus, and present evidence for the impacts of climate, land use, and biological invasions on Aedes mosquito communities. Last, we discuss important questions about the ecology of La Crosse virus mosquito vectors that may improve our understanding of the impacts of environmental changes on La Crosse virus and other arboviruses. PMID:22692799

  5. Mosquito Fauna (Diptera: Culicidae) of Hamedan County, Western Iran

    PubMed Central

    Zahirnia, Amir Hossein; Zendehfili, Hamid

    2014-01-01

    Background: This study aimed to identify and determine the larval and adult mosquitoes (Culicidae) fauna in Hamedan County, western Iran. Methods: It was a cross-sectional study which took place in four area of the Hamedan County. Sampling methods for larvae, pupae and adults were dipping, hand catch, night catch and total catch. Larvae and adult mosquitoes collected and were sent to laboratory of Medical Entomology, Hamedan University of Medical Sciences, Hamedan, Iran for further identification to species level to determination of fauna. Data analysis was performed using SPSS software version19. Results: Three genera and eight species of family Culicidae were collected and identified in Hamedan County, Hamedan Province, West Iran, during May to October 2013. These species included: Culex theileri, Cx. pipiens, Cx. antennatus, Culiseta subochrea, Cs. langiareolata, Anopheles superpictus, An. maculipennis and An. stephensi. The species Cx. antennatus and An. stephensi were reported for the first time in Hamedan County. Conclusion: An. stephensi and Cx. antennatus caught had not been previously recorded in Hamedan Province. Due to vast agricultural activities in the province which provides suitable environment for the establishment of various species of mosquitoes and since many of them are potential vectors of human and domesticated animal pathogens, their ecology needs to be studied extensively.

  6. Advantages and limitations of commercially available electrocuting grids for studying mosquito behaviour

    PubMed Central

    2013-01-01

    Background Mosquito feeding behaviour plays a major role in determining malaria transmission intensity and the impact of specific prevention measures. Human Landing Catch (HLC) is currently the only method that can directly and consistently measure the biting rates of anthropophagic mosquitoes, both indoors and outdoors. However, this method exposes the participant to mosquito-borne pathogens, therefore new exposure-free methods are needed to replace it. Methods Commercially available electrocuting grids (EGs) were evaluated as an alternative to HLC using a Latin Square experimental design in Dar es Salaam, Tanzania. Both HLC and EGs were used to estimate the proportion of human exposure to mosquitoes occurring indoors (?i), as well as its two underlying parameters: the proportion of mosquitoes caught indoors (Pi) and the proportion of mosquitoes caught between the first and last hour when most people are indoors (Pfl). Results HLC and EGs methods accounted for 69% and 31% of the total number of female mosquitoes caught respectively and both methods caught more mosquitoes outdoors than indoors. Results from the gold standard HLC suggest that An. gambiae s.s. in Dar es Salaam is neither exophagic nor endophagic (Pi???0.5), whereas An. arabiensis is exophagic (Pi??>?0.5). EGs yielded estimates of Pi for An. gambiae s.s., An. arabiensis and An. coustani, that were approximately equivalent to those with HLC but significantly underestimated Pfl for An. gambiae s.s. and An. coustani. The relative sampling sensitivity of EGs declined over the course of the night (p???0.001) for all mosquito taxa except An. arabiensis. Conclusions Commercial EGs sample human-seeking mosquitoes with high sensitivity both indoors and outdoors and accurately measure the propensity of Anopheles malaria vectors to bite indoors rather than outdoors. However, further modifications are needed to stabilize sampling sensitivity over a full nocturnal cycle so that they can be used to survey patterns of human exposure to mosquitoes. PMID:23497704

  7. A tale of two city blocks: differences in immature and adult mosquito abundances between socioeconomically different urban blocks in Baltimore (Maryland, USA).

    PubMed

    Becker, Brian; Leisnham, Paul T; LaDeau, Shannon L

    2014-03-01

    Infrastructure degradation in many post-industrial cities has increased the availability of potential mosquito habitats, including container habitats that support infestations of invasive disease-vectors. This study is unique in examining both immature and adult mosquito abundance across the fine-scale variability in socio-economic condition that occurs block-to-block in many cities. We hypothesized that abundant garbage associated with infrastructure degradation would support greater mosquito production but instead, found more mosquito larvae and host-seeking adults (86%) in parcels across the higher socio-economic, low-decay block. Aedes albopictus and Culex pipiens were 5.61 (p < 0.001) and 4.60 (p = 0.001) times more abundant, respectively. Most discarded (garbage) containers were dry during peak mosquito production, which occurred during the 5th hottest July on record. Containers associated with human residence were more likely to hold water and contain immature mosquitoes. We propose that mosquito production switches from rain-fed unmanaged containers early in the season to container habitats that are purposefully shaded or watered by mid-season. This study suggests that residents living in higher socioeconomic areas with low urban decay may be at greater risk of mosquito-borne disease during peak mosquito production when local container habitats are effectively decoupled from environmental constraints. PMID:24651396

  8. West Nile Virus Epidemics in North America Are Driven by Shifts in Mosquito Feeding Behavior

    PubMed Central

    Kramer, Laura D; Jones, Matthew J; Marra, Peter P; Daszak, Peter

    2006-01-01

    West Nile virus (WNV) has caused repeated large-scale human epidemics in North America since it was first detected in 1999 and is now the dominant vector-borne disease in this continent. Understanding the factors that determine the intensity of the spillover of this zoonotic pathogen from birds to humans (via mosquitoes) is a prerequisite for predicting and preventing human epidemics. We integrated mosquito feeding behavior with data on the population dynamics and WNV epidemiology of mosquitoes, birds, and humans. We show that Culex pipiens, the dominant enzootic (bird-to-bird) and bridge (bird-to-human) vector of WNV in urbanized areas in the northeast and north-central United States, shifted its feeding preferences from birds to humans by 7-fold during late summer and early fall, coinciding with the dispersal of its preferred host (American robins, Turdus migratorius) and the rise in human WNV infections. We also show that feeding shifts in Cx. tarsalis amplify human WNV epidemics in Colorado and California and occur during periods of robin dispersal and migration. Our results provide a direct explanation for the timing and intensity of human WNV epidemics. Shifts in feeding from competent avian hosts early in an epidemic to incompetent humans after mosquito infection prevalences are high result in synergistic effects that greatly amplify the number of human infections of this and other pathogens. Our results underscore the dramatic effects of vector behavior in driving the transmission of zoonotic pathogens to humans. PMID:16494532

  9. West Nile virus epidemics in North America are driven by shifts in mosquito feeding behavior.

    PubMed

    Kilpatrick, A Marm; Kramer, Laura D; Jones, Matthew J; Marra, Peter P; Daszak, Peter

    2006-04-01

    West Nile virus (WNV) has caused repeated large-scale human epidemics in North America since it was first detected in 1999 and is now the dominant vector-borne disease in this continent. Understanding the factors that determine the intensity of the spillover of this zoonotic pathogen from birds to humans (via mosquitoes) is a prerequisite for predicting and preventing human epidemics. We integrated mosquito feeding behavior with data on the population dynamics and WNV epidemiology of mosquitoes, birds, and humans. We show that Culex pipiens, the dominant enzootic (bird-to-bird) and bridge (bird-to-human) vector of WNV in urbanized areas in the northeast and north-central United States, shifted its feeding preferences from birds to humans by 7-fold during late summer and early fall, coinciding with the dispersal of its preferred host (American robins, Turdus migratorius) and the rise in human WNV infections. We also show that feeding shifts in Cx. tarsalis amplify human WNV epidemics in Colorado and California and occur during periods of robin dispersal and migration. Our results provide a direct explanation for the timing and intensity of human WNV epidemics. Shifts in feeding from competent avian hosts early in an epidemic to incompetent humans after mosquito infection prevalences are high result in synergistic effects that greatly amplify the number of human infections of this and other pathogens. Our results underscore the dramatic effects of vector behavior in driving the transmission of zoonotic pathogens to humans. PMID:16494532

  10. Serratia odorifera a Midgut Inhabitant of Aedes aegypti Mosquito Enhances Its Susceptibility to Dengue-2 Virus

    PubMed Central

    Apte-Deshpande, Anjali; Paingankar, Mandar; Gokhale, Mangesh D.; Deobagkar, Dileep N.

    2012-01-01

    Mosquito midgut plays a crucial role in its vector susceptibility and pathogen interaction. Identification of the sustainable microflora of the midgut environment can therefore help in evaluating its contribution in mosquito-pathogen interaction and in turn vector competence. To understand the bacterial diversity in the midgut of Aedes aegypti mosquitoes, we conducted a screening study of the gut microbes of these mosquitoes which were either collected from fields or reared in the laboratory “culture-dependent” approach. This work demonstrated that the microbial flora of larvae and adult Ae. aegypti midgut is complex and is dominated by Gram negative proteobacteria. Serratia odorifera was found to be stably associated in the midguts of field collected and laboratory reared larvae and adult females. The potential influence of this sustainable gut microbe on DENV-2 susceptibility of this vector was evaluated by co-feeding S. odorifera with DENV-2 to adult Ae. aegypti females (free of gut flora). The observations revealed that the viral susceptibility of these Aedes females enhanced significantly as compared to solely dengue-2 fed and another gut inhabitant, Microbacterium oxydans co-fed females. Based on the results of this study we proposed that the enhancement in the DENV-2 susceptibility of Ae. aegypti females was due to blocking of prohibitin molecule present on the midgut surface of these females by the polypeptide of gut inhabitant S. odorifera. PMID:22848375

  11. Silent, Generic and Plant Kairomone Sensitive Odorant Receptors from the Southern House Mosquito

    PubMed Central

    Xu, Pingxi; Choo, Young-Moo; Pelletier, Julien; Sujimoto, Fernando R.; Hughes, David T.; Zhu, Fen; Atungulu, Elizabeth; Cornel, Anthony J.; Luetje, Charles W.; Leal, Walter S.

    2013-01-01

    The Southern house mosquito Culex quinquefasciatus has the largest repertoire of odorant receptors (ORs) of all mosquitoes and dipteran species whose genomes have been sequenced to date. Previously, we have identified and de-orphanized two ORs expressed in female antennae, CquiOR2 and CquiOR10, which are sensitive to oviposition attractants. In view of a new nomenclature for the Culex genome (VectorBase) we renamed these ORs as CquiOR21 (formerly CquiOR10) and CquiOR121 (CquiOR2). In addition, we selected ORs from six different phylogenetic groups for deorphanization. We cloned four of them by using cDNA from female antennae as a template. Attempts to clone CquiOR87 and CquiOR110 were unsuccessful either because they are pseudogenes or are not expressed in adult female antennae, the main olfactory tissue. By contrast, CquiOR1, CquiOR44, CquiOR73, and CquiOR161 were highly expressed in female antennae. To de-orphanize these ORs, we employed the Xenopus oocyte recording system. CquiORx-CquiOrco-expressed oocytes were challenged with a panel of 90 compounds, including known oviposition attractants, human and vertebrate host odorants, plant kairomones, and naturally occuring repellents. While CquiOR161 did not respond to any test compound in two different laboratories, CquiOR1 showed the features of a generic OR, with strong responses to 1-octen-3-ol and other ligands. CquiOR44 and CquiOR73 showed preference to plant-derived terpenoids and phenolic compounds, respectively. While fenchone was the best ligand for the former, 3,5-dimethylphenol elicited the strongest responses in the latter. The newly de-orphanized ORs may be involved in reception of plant kairomones and/or natural repellents. PMID:23876610

  12. Signatures of aestivation and migration in Sahelian malaria mosquito populations.

    PubMed

    Dao, A; Yaro, A S; Diallo, M; Timbiné, S; Huestis, D L; Kassogué, Y; Traoré, A I; Sanogo, Z L; Samaké, D; Lehmann, T

    2014-12-18

    During the long Sahelian dry season, mosquito vectors of malaria are expected to perish when no larval sites are available; yet, days after the first rains, mosquitoes reappear in large numbers. How these vectors persist over the 3-6-month long dry season has not been resolved, despite extensive research for over a century. Hypotheses for vector persistence include dry-season diapause (aestivation) and long-distance migration (LDM); both are facets of vector biology that have been highly controversial owing to lack of concrete evidence. Here we show that certain species persist by a form of aestivation, while others engage in LDM. Using time-series analyses, the seasonal cycles of Anopheles coluzzii, Anopheles gambiae sensu stricto (s.s.), and Anopheles arabiensis were estimated, and their effects were found to be significant, stable and highly species-specific. Contrary to all expectations, the most complex dynamics occurred during the dry season, when the density of A. coluzzii fluctuated markedly, peaking when migration would seem highly unlikely, whereas A. gambiae s.s. was undetected. The population growth of A. coluzzii followed the first rains closely, consistent with aestivation, whereas the growth phase of both A. gambiae s.s. and A. arabiensis lagged by two months. Such a delay is incompatible with local persistence, but fits LDM. Surviving the long dry season in situ allows A. coluzzii to predominate and form the primary force of malaria transmission. Our results reveal profound ecological divergence between A. coluzzii and A. gambiae s.s., whose standing as distinct species has been challenged, and suggest that climate is one of the selective pressures that led to their speciation. Incorporating vector dormancy and LDM is key to predicting shifts in the range of malaria due to global climate change, and to the elimination of malaria from Africa. PMID:25470038

  13. Identification of morphological and chemical markers of dry- and wet-season conditions in female Anopheles gambiae mosquitoes

    PubMed Central

    2014-01-01

    Background Increased understanding of the dry-season survival mechanisms of Anopheles gambiae in semi-arid regions could benefit vector control efforts by identifying weak links in the transmission cycle of malaria. In this study, we examined the effect of photoperiod and relative humidity on morphologic and chemical traits known to control water loss in mosquitoes. Methods Anopheles gambiae body size (indexed by wing length), mesothoracic spiracle size, and cuticular hydrocarbon composition (both standardized by body size) were examined in mosquitoes raised from eggs exposed to short photoperiod and low relative humidity, simulating the dry season, or long photoperiod and high relative humidity, simulating the wet-season. Results Mosquitoes exposed to short photoperiod exhibited larger body size and larger mesothoracic spiracle length than mosquitoes exposed to long photoperiod. Mosquitoes exposed to short photoperiod and low relative humidity exhibited greater total cuticular hydrocarbon amount than mosquitoes exposed to long photoperiod and high relative humidity. In addition, total cuticular hydrocarbon amount increased with age and was higher in mated females. Mean n-alkane retention time (a measure of cuticular hydrocarbon chain length) was lower in mosquitoes exposed to short photoperiod and low relative humidity, and increased with age. Individual cuticular hydrocarbon peaks were examined, and several cuticular hydrocarbons were identified as potential biomarkers of dry- and wet-season conditions, age, and insemination status. Conclusions Results from this study indicate that morphological and chemical changes underlie aestivation of Anopheles gambiae and may serve as biomarkers of aestivation. PMID:24970701

  14. A network-patch methodology for adapting agent-based models for directly transmitted disease to mosquito-borne disease.

    PubMed

    Manore, Carrie A; Hickmann, Kyle S; Hyman, James M; Foppa, Ivo M; Davis, Justin K; Wesson, Dawn M; Mores, Christopher N

    2015-01-01

    Mosquito-borne diseases cause significant public health burden and are widely re-emerging or emerging. Understanding, predicting, and mitigating the spread of mosquito-borne disease in diverse populations and geographies are ongoing modelling challenges. We propose a hybrid network-patch model for the spread of mosquito-borne pathogens that accounts for individual movement through mosquito habitats, extending the capabilities of existing agent-based models (ABMs) to include vector-borne diseases. The ABM are coupled with differential equations representing 'clouds' of mosquitoes in patches accounting for mosquito ecology. We adapted an ABM for humans using this method and investigated the importance of heterogeneity in pathogen spread, motivating the utility of models of individual behaviour. We observed that the final epidemic size is greater in patch models with a high risk patch frequently visited than in a homogeneous model. Our hybrid model quantifies the importance of the heterogeneity in the spread of mosquito-borne pathogens, guiding mitigation strategies. PMID:25648061

  15. Invited Review Malaria parasite colonisation of the mosquito midgut Placing

    E-print Network

    McFadden, Geoff

    Invited Review Malaria parasite colonisation of the mosquito midgut ­ Placing the Plasmodium 3 March 2012 Keywords: Malaria Plasmodium Mosquito Anopheles Ookinete Oocyst Midgut traversal drugs is emerging. Malaria parasite migration through the mosquito host constitutes a major population

  16. Spatial Evaluation and Modeling of Dengue Seroprevalence and Vector Density in Rio de Janeiro, Brazil

    PubMed Central

    Honório, Nildimar Alves; Nogueira, Rita Maria Ribeiro; Codeço, Cláudia Torres; Carvalho, Marilia Sá; Cruz, Oswaldo Gonçalves; de Avelar Figueiredo Mafra Magalhães, Mônica; de Araújo, Josélio Maria Galvão; de Araújo, Eliane Saraiva Machado; Gomes, Marcelo Quintela; Pinheiro, Luciane Silva; da Silva Pinel, Célio; Lourenço-de-Oliveira, Ricardo

    2009-01-01

    Background Rio de Janeiro, Brazil, experienced a severe dengue fever epidemic in 2008. This was the worst epidemic ever, characterized by a sharp increase in case-fatality rate, mainly among younger individuals. A combination of factors, such as climate, mosquito abundance, buildup of the susceptible population, or viral evolution, could explain the severity of this epidemic. The main objective of this study is to model the spatial patterns of dengue seroprevalence in three neighborhoods with different socioeconomic profiles in Rio de Janeiro. As blood sampling coincided with the peak of dengue transmission, we were also able to identify recent dengue infections and visually relate them to Aedes aegypti spatial distribution abundance. We analyzed individual and spatial factors associated with seroprevalence using Generalized Additive Model (GAM). Methodology/Principal Findings Three neighborhoods were investigated: a central urban neighborhood, and two isolated areas characterized as a slum and a suburban area. Weekly mosquito collections started in September 2006 and continued until March 2008. In each study area, 40 adult traps and 40 egg traps were installed in a random sample of premises, and two infestation indexes calculated: mean adult density and mean egg density. Sera from individuals living in the three neighborhoods were collected before the 2008 epidemic (July through November 2007) and during the epidemic (February through April 2008). Sera were tested for DENV-reactive IgM, IgG, Nested RT-PCR, and Real Time RT-PCR. From the before–after epidemics paired data, we described seroprevalence, recent dengue infections (asymptomatic or not), and seroconversion. Recent dengue infection varied from 1.3% to 14.1% among study areas. The highest IgM seropositivity occurred in the slum, where mosquito abundance was the lowest, but household conditions were the best for promoting contact between hosts and vectors. By fitting spatial GAM we found dengue seroprevalence hotspots located at the entrances of the two isolated communities, which are commercial activity areas with high human movement. No association between recent dengue infection and household's high mosquito abundance was observed in this sample. Conclusions/Significance This study contributes to better understanding the dynamics of dengue in Rio de Janeiro by assessing the relationship between dengue seroprevalence, recent dengue infection, and vector density. In conclusion, the variation in spatial seroprevalence patterns inside the neighborhoods, with significantly higher risk patches close to the areas with large human movement, suggests that humans may be responsible for virus inflow to small neighborhoods in Rio de Janeiro. Surveillance guidelines should be further discussed, considering these findings, particularly the spatial patterns for both human and mosquito populations. PMID:19901983

  17. Source reduction of mosquito larval habitats has unexpected consequences on malaria transmission

    PubMed Central

    Gu, Weidong; Regens, James L.; Beier, John C.; Novak, Robert J.

    2006-01-01

    Reduction of aquatic habitats through environmental management mitigates malaria transmission not only by reducing emergence of host-seeking mosquitoes, but also by increasing the amount of time required for vectors to locate oviposition sites. However, the consequence of source reduction on mosquito oviposition has largely been neglected in evaluations of environment-management programs. Here, by theoretically examining the relationship between the time spent for oviposition and the availability of aquatic habitats, we show that prolonged oviposition cycles induced by source reduction account for a great deal of reductions in the basic reproductive rate of malaria, especially when aquatic habitats are scarce and the mosquito's flight ability is limited. Neglecting this mechanism may lead to substantial underestimation of the impact of source reduction of aquatic habitats on malaria transmission. Our findings suggest that the prolonged duration of the gonotrophic cycle might be one of the important mechanisms underlying the effectiveness of environment-management interventions for malaria control. PMID:17085587

  18. Needs for Monitoring Mosquito Transmission of Malaria in a Pre-Elimination World

    PubMed Central

    James, Stephanie; Takken, Willem; Collins, Frank H.; Gottlieb, Michael

    2014-01-01

    As global efforts to eliminate malaria intensify, accurate information on vector populations and transmission dynamics is critical for directing control efforts, developing new control tools, and predicting the effects of these interventions under various conditions. Currently available sampling tools for mosquito population monitoring suffer from well-recognized limitations. As reported in this workshop summary, a recent gathering of medical entomologists, modelers, and malaria experts reviewed these issues and agreed that efforts are needed to improve methods to monitor key transmission parameters. Identified needs include standardized methods for sampling of both mosquito adults and larvae, improved tools for mosquito species identification and age-grading, and a better means for determining the entomological inoculation rate. PMID:24277786

  19. Sustainable control of mosquito larvae in the field by the combined actions of the biological insecticide Bti and natural competitors.

    PubMed

    Kroeger, Iris; Liess, Matthias; Dziock, Frank; Duquesne, Sabine

    2013-06-01

    Integrated management of mosquitoes is becoming increasingly important, particularly in relation to avoiding recolonization of ponds after larvicide treatment. We conducted for the first time field experiments that involved exposing natural populations of the mosquito species Culex pipiens to: a) application of the biological insecticide Bacillus thuringiensis israelensis (Bti), b) the introduction of natural competitors (a crustacean community composed mainly of Daphnia spp.), or c) a combined treatment that involved both introduction of a crustacean community and the application of Bti. The treatment that involved only the introduction of crustaceans had no significant effect on mosquito larval populations, while treatment with Bti alone caused only a significant reduction in the abundance of mosquito larvae in the short-term (within 3-10 days after treatment). In contrast, the combined treatment rapidly reduced the abundance of mosquito larvae, which remained low throughout the entire observation period of 28 days. Growth of the introduced crustacean communities was favored by the immediate reduction in the abundance of mosquito larvae following Bti administration, thus preventing recolonization of ponds by mosquito larvae at the late period (days 14-28 after treatment). Both competition and the temporal order of establishment of different species are hence important mechanisms for efficient and sustainable mosquito control. PMID:23701611

  20. Divergent and conserved elements comprise the chemoreceptive repertoire of the nonblood-feeding mosquito Toxorhynchites amboinensis.

    PubMed

    Zhou, Xiaofan; Rinker, David C; Pitts, Ronald Jason; Rokas, Antonis; Zwiebel, Laurence J

    2014-10-01

    Many mosquito species serve as vectors of diseases such as malaria and yellow fever, wherein pathogen transmission is tightly associated with the reproductive requirement of taking vertebrate blood meals. Toxorhynchites is one of only three known mosquito genera that does not host-seek and initiates egg development in the absence of a blood-derived protein bolus. These remarkable differences make Toxorhynchites an attractive comparative reference for understanding mosquito chemosensation as it pertains to host-seeking. We performed deep transcriptome profiling of adult female Toxorhynchites amboinensis bodies, antennae and maxillary palps, and identified 25,084 protein-coding "genes" in the de novo assembly. Phylogenomic analysis of 4,266 single-copy "genes" from T. amboinensis, Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus robustly supported Ae. aegypti as the closest relative of T. amboinensis, with the two species diverged approximately 40 Ma. We identified a large number of T. amboinensis chemosensory "genes," the majority of which have orthologs in other mosquitoes. Finally, cross-species expression analyses indicated that patterns of chemoreceptor transcript abundance were very similar for chemoreceptors that are conserved between T. amboinensis and Ae. aegypti, whereas T. amboinensis appeared deficient in the variety of expressed, lineage-specific chemoreceptors. Our transcriptome assembly of T. amboinensis represents the first comprehensive genomic resource for a nonblood-feeding mosquito and establishes a foundation for future comparative studies of blood-feeding and nonblood-feeding mosquitoes. We hypothesize that chemosensory genes that display discrete patterns of evolution and abundance between T. amboinensis and blood-feeding mosquitoes are likely to play critical roles in host-seeking and hence the vectorial capacity. PMID:25326137

  1. Colonization of UK coastal realignment sites by mosquitoes: implications for design, management, and public health.

    PubMed

    Medlock, J M; Vaux, A G C

    2013-06-01

    Coastal realignment is now widely instituted in the UK as part of local flood risk management plans to compensate for the loss of European protected habitat and to mitigate the effects of sea-level rise and coastal squeeze. Coastal aquatic habitats have long been known to provide suitable habitats for brackish-water mosquitoes and historically, coastal marshes were considered to support anopheline mosquito populations that were responsible for local malaria transmission. This study surveyed the eight largest managed realignment (MRA) sites in England (Essex and the Humber) for mosquito habitats. The apparent absence of anopheline mosquitoes exploiting aquatic habitats at all of these sites suggests that the risk of malaria associated with MRA sites is currently negligible. However, three of the eight sites supported populations of two nuisance and potential arboviral vector species, Aedes detritus and Aedes caspius. The aquatic habitats that supported mosquitoes resulted from a) specific design aspects of the new sea wall (ballast to mitigate wave action and constructed saline borrow ditches) that could be designed out or managed or b) isolated pools created through silt accretion or expansion of flooded zones to neighbouring pasture. The public health risks and recommendations for management are discussed in this report. This report highlights the need for pro-active public health impact assessments prior to MRA development in consultation with the Health Protection Agency, as well as the need for a case-by-case approach to design and management to mitigate mosquito or mosquito-borne disease issues now and in the future. PMID:23701607

  2. Divergent and Conserved Elements Comprise the Chemoreceptive Repertoire of the Nonblood-Feeding Mosquito Toxorhynchites amboinensis

    PubMed Central

    Zhou, Xiaofan; Rinker, David C.; Pitts, Ronald Jason; Rokas, Antonis; Zwiebel, Laurence J.

    2014-01-01

    Many mosquito species serve as vectors of diseases such as malaria and yellow fever, wherein pathogen transmission is tightly associated with the reproductive requirement of taking vertebrate blood meals. Toxorhynchites is one of only three known mosquito genera that does not host-seek and initiates egg development in the absence of a blood-derived protein bolus. These remarkable differences make Toxorhynchites an attractive comparative reference for understanding mosquito chemosensation as it pertains to host-seeking. We performed deep transcriptome profiling of adult female Toxorhynchites amboinensis bodies, antennae and maxillary palps, and identified 25,084 protein-coding “genes” in the de novo assembly. Phylogenomic analysis of 4,266 single-copy “genes” from T. amboinensis, Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus robustly supported Ae. aegypti as the closest relative of T. amboinensis, with the two species diverged approximately 40 Ma. We identified a large number of T. amboinensis chemosensory “genes,” the majority of which have orthologs in other mosquitoes. Finally, cross-species expression analyses indicated that patterns of chemoreceptor transcript abundance were very similar for chemoreceptors that are conserved between T. amboinensis and Ae. aegypti, whereas T. amboinensis appeared deficient in the variety of expressed, lineage-specific chemoreceptors. Our transcriptome assembly of T. amboinensis represents the first comprehensive genomic resource for a nonblood-feeding mosquito and establishes a foundation for future comparative studies of blood-feeding and nonblood-feeding mosquitoes. We hypothesize that chemosensory genes that display discrete patterns of evolution and abundance between T. amboinensis and blood-feeding mosquitoes are likely to play critical roles in host-seeking and hence the vectorial capacity. PMID:25326137

  3. Transient Population Dynamics of Mosquitoes during Sterile Male Releases: Modelling Mating Behaviour and Perturbations of Life History Parameters

    PubMed Central

    Stone, Christopher M.

    2013-01-01

    The release of genetically-modified or sterile male mosquitoes offers a promising form of mosquito-transmitted pathogen control, but the insights derived from our understanding of male mosquito behaviour have not fully been incorporated into the design of such genetic control or sterile-male release methods. The importance of aspects of male life history and mating behaviour for sterile-male release programmes were investigated by projecting a stage-structured matrix model over time. An elasticity analysis of transient dynamics during sterile-male releases was performed to provide insight on which vector control methods are likely to be most synergistic. The results suggest that high mating competitiveness and mortality costs of released males are required before the sterile-release method becomes ineffective. Additionally, if released males suffer a mortality cost, older males should be released due to their increased mating capacity. If released males are of a homogenous size and size-assortative mating occurs in nature, this can lead to an increase in the abundance of large females and reduce the efficacy of the population-suppression effort. At a high level of size-assortative mating, the disease transmission potential of the vector population increases due to male releases, arguing for the release of a heterogeneously-sized male population. The female population was most sensitive to perturbations of density-dependent components of larval mortality and female survivorship and fecundity. These findings suggest source reduction might be a particularly effective complement to mosquito control based on the sterile insect technique (SIT). In order for SIT to realize its potential as a key component of an integrated vector-management strategy to control mosquito-transmitted pathogens, programme design of sterile-male release programmes must account for the ecology, behaviour and life history of mosquitoes. The model used here takes a step in this direction and can easily be modified to investigate additional aspects of mosquito behaviour or species-specific ecology. PMID:24086715