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Sample records for mosquito control

  1. Mosquito Control

    Science.gov (United States)

    ... Share Facebook Twitter Google+ Pinterest Contact Us Mosquito Control About Mosquitoes General Information Life Cycle Information on ... is Right for You DEET Pesticides for Mosquito Control Larvicides Adulticides Misting Systems Getting Help with Mosquito ...

  2. Pesticides and Mosquito Control

    Science.gov (United States)

    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. HERBAL CONTROL OF MOSQUITO LARVAE

    OpenAIRE

    Chaudhari Priyanka S, Chaudhari Sv Jangam Sampada

    2013-01-01

    Mosquitoes are the vectors for the dreadful diseases of mankind. For control of larval stages of mosquito, herbal plant extracts/ botanical insecticides are being tried. In the present study aqueous extract of some traditional medicinal herbal plants i.e. Neem (Azadirechta indica), Tobacco (Nicotiana tabacum), Turmeric (Curcuma longa), Tulasi (Ocimum santum), and Ginger (Zingiber officinale) were tested for their Larvicidal activity. The successful attempt is made to kill the larvae, the prem...

  4. HERBAL CONTROL OF MOSQUITO LARVAE

    Directory of Open Access Journals (Sweden)

    Chaudhari Priyanka S, Chaudhari SV* Jangam Sampada, Shinde JS, Wankhede Sneha

    2013-04-01

    Full Text Available Mosquitoes are the vectors for the dreadful diseases of mankind. For control of larval stages of mosquito, herbal plant extracts/ botanical insecticides are being tried. In the present study aqueous extract of some traditional medicinal herbal plants i.e. Neem (Azadirechta indica, Tobacco (Nicotiana tabacum, Turmeric (Curcuma longa, Tulasi (Ocimum santum, and Ginger (Zingiber officinale were tested for their Larvicidal activity. The successful attempt is made to kill the larvae, the premature stage of mosquitoes by using safe and socio-economical herbal plant extract mixtures. Ginger+Tobacco, Neem+Tobbaco and Ginger Neem, Turmeric, Tobacco and Tulasi showed highest larvicidal activity. The results obtained show that this plant material exhibited larvicidal activity and could be considered as potent natural larvicidal agent without any toxic effects.

  5. New Innovations in Biological Control of Mosquitoes.

    Science.gov (United States)

    Biological control of mosquitoes is a component of an integrated pest management strategy and includes general predators, parasites and pathogens. Pathogens of mosquitoes include bacteria, viruses, fungi and protists. The most successful group for applied mosquito control include the bacteria Baci...

  6. North American Wetlands and Mosquito Control

    OpenAIRE

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

    2012-01-01

    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 ...

  7. North American Wetlands and Mosquito Control

    Directory of Open Access Journals (Sweden)

    Gabrielle E. Sakolsky-Hoopes

    2012-12-01

    Full Text Available 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.

  8. Entomopathogenic fungi for mosquito control: a review.

    Science.gov (United States)

    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. Entomopathogenic fungi for mosquito control: A review

    Directory of Open Access Journals (Sweden)

    Ernst-Jan Scholte

    2004-06-01

    Full Text Available 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.

  10. Mosquito Modifications: New Approaches to Controlling Malaria

    Science.gov (United States)

    Sharon Levy (; )

    2007-11-01

    This article from the November 2007 issue of BioScience examines the historical and current methods to control Malaria.Malaria kills about one million people each year, but efforts to destroy disease-carrying mosquitoes have succeeded only in breeding tougher bugs. Researchers have begun to look for ways to create malaria-resistant mosquitoes. One approach is to bioengineer transgenic mosquitoes that, when released into the wild, would lead to a new race of malaria-proof young. Another approach uses mosquitoes' natural resistance to Plasmodium infection.

  11. Novel Methods for Mosquito Control using RNAi.

    Science.gov (United States)

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  14. Genetic Control of Mosquitoes: population suppression strategies Controle genético de mosquitos: estratégias de supressão de populações

    Directory of Open Access Journals (Sweden)

    André Barretto Bruno Wilke

    2012-10-01

    Full Text Available Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.Ao longo das duas últimas décadas, morbidade e mortalidade da malária e dengue e outros patógenos tem se tornado cada vez mais um problema de Saúde Pública. O aumento na distribuição geográfica de seus respectivos vetores é acompanhada pela emergência de doenças em novas áreas. Não estão disponíveis drogas específicas suficientes e não há vacinas específicas para imunizar as populações alvo. As medidas de controle de mosquitos atuais falharam em atingir os objetivos propostos, principalmente devido à grande capacidade reprodutiva dos mosquitos e alta flexibilidade genômica. O controle químico se torna cada vez mais restrito devido a sua potencial toxicidade aos seres humanos, mortalidade de organismos não alvos, resistência a inseticida além de outros impactos ambientais. Novas estratégias de controle são necessárias. A técnica do inseto estéril (SIT é um método de supressão populacional espécie específico e ambientalmente amigável, baseia-se na criação em massa, esterilização mediante irradiação e liberação de um grande número de insetos machos. Liberar insetos carregando um gene letal dominante (RIDL oferece uma solução a muitas limitações impostas pela técnica do inseto estéril (SIT que limitaram sua aplicação em mosquitos e ainda assim mantém suas características de ambientalmente amigável e espécie específica. A natureza auto-limitante de mosquitos estéreis tende a deixar alguns empecilhos para uso no campo, de certa forma, menos desafiadores quando comparados a sistemas auto-propagação, característicos de estratégias de substituição de população. Sistemas auto-limitantes estão mais próximos para uso no campo, portanto pode ser apropriado considerá-lo primeiro. A perspectiva de métodos de controle genéticos contra mosquitos vetores de doenças que acometem humanos está rapidamente se tornando uma realidade, muitas decisões terão de ser tomadas em âmbito nacional, regional e internacional com relação a aspectos étnicos, sociais, culturais e de biossegurança para o uso e liberação

  15. Genetic Control of Mosquitoes: population suppression strategies / Controle genético de mosquitos: estratégias de supressão de populações

    Scientific Electronic Library Online (English)

    André Barretto Bruno, Wilke; Mauro Toledo, Marrelli.

    2012-10-01

    Full Text Available Ao longo das duas últimas décadas, morbidade e mortalidade da malária e dengue e outros patógenos tem se tornado cada vez mais um problema de Saúde Pública. O aumento na distribuição geográfica de seus respectivos vetores é acompanhada pela emergência de doenças em novas áreas. Não estão disponíveis [...] drogas específicas suficientes e não há vacinas específicas para imunizar as populações alvo. As medidas de controle de mosquitos atuais falharam em atingir os objetivos propostos, principalmente devido à grande capacidade reprodutiva dos mosquitos e alta flexibilidade genômica. O controle químico se torna cada vez mais restrito devido a sua potencial toxicidade aos seres humanos, mortalidade de organismos não alvos, resistência a inseticida além de outros impactos ambientais. Novas estratégias de controle são necessárias. A técnica do inseto estéril (SIT) é um método de supressão populacional espécie específico e ambientalmente amigável, baseia-se na criação em massa, esterilização mediante irradiação e liberação de um grande número de insetos machos. Liberar insetos carregando um gene letal dominante (RIDL) oferece uma solução a muitas limitações impostas pela técnica do inseto estéril (SIT) que limitaram sua aplicação em mosquitos e ainda assim mantém suas características de ambientalmente amigável e espécie específica. A natureza auto-limitante de mosquitos estéreis tende a deixar alguns empecilhos para uso no campo, de certa forma, menos desafiadores quando comparados a sistemas auto-propagação, característicos de estratégias de substituição de população. Sistemas auto-limitantes estão mais próximos para uso no campo, portanto pode ser apropriado considerá-lo primeiro. A perspectiva de métodos de controle genéticos contra mosquitos vetores de doenças que acometem humanos está rapidamente se tornando uma realidade, muitas decisões terão de ser tomadas em âmbito nacional, regional e internacional com relação a aspectos étnicos, sociais, culturais e de biossegurança para o uso e liberação destes métodos de controle de vetores. Abstract in english Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific [...] therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT) is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL) offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural a

  16. New Toxicants for Mosquito Control.

    Science.gov (United States)

    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...

  17. NEW TRAPS FOR MOSQUITO POPULATION SURVEILLANCE AND CONTROL

    Science.gov (United States)

    In 1989 there were two basic traps available for mosquito surveillance, the Centers for Disease Control (CDC) and the New Jersey (NJ) light trap. These traps were not considered to be useful for population control. Bug Zappers were the only available device marketed for mosquito control. Since 1...

  18. Does mosquito control have an effect on mosquito-borne disease? The case of Ross River virus disease and mosquito management in Queensland, Australia.

    Science.gov (United States)

    Tomerini, Deanna M; Dale, Pat E; Sipe, Neil

    2011-03-01

    We examined the relationship between types of mosquito control programs and the mosquito-borne Ross River virus (RRV) disease in Queensland, Australia. Mosquito control information was collected through a survey of the responsible agencies (local governments), and RRV disease notification data were provided by the Queensland state health authority. The study developed a typology of mosquito control programs, based on the approaches used. Based on the analysis of data on RRV disease rates between mosquito control types within 4 climatic regions, each region had different combinations of mosquito control strategies in their programs; there were also general similarities in the relationship between program types and RRV rates between the regions. The long-term RRV disease rates were lower in areas where the mosquito control program included pre-emptive (rather than reactive) surveillance based on an extensive (rather than incomplete) knowledge of mosquito habitats, and where treatment of both saltwater and freshwater habitats (compared to only saltwater habitats, in coastal areas) occurred. The data indicate that mosquito control is an effective public health intervention to reduce mosquito-borne disease; hence, climate change adaptation strategies should ensure that adequate resources are available for effective vector control so as to manage the risk of mosquito-borne diseases. PMID:21476446

  19. Genetic Methods for Control of Mosquitoes

    International Nuclear Information System (INIS)

    This summary of past experiments and pilot projects on the genetic control of mosquitoes is not intended to be an exhaustive review. Emphasis has been placed on: 1) successful research efforts on the use of the sterile insect technique (SIT) and the synthesis of useful heritable chromosomal aberrations, 2) the technical limitations in our present ability to use SIT, 3) the need for genetic evaluation of the structure of natural populations, and 4) a look at the future impact of recombinant DNA methods on genetic control. A generally optimistic point of view of the current and future situations from the author's perspective will be expressed, with emphasis on successful research efforts. Past failures will not be ignored, but neither will they be presented as irrefutable evidence of doom for genetic control.

  20. Control of mosquitoes by the sterile male technique

    International Nuclear Information System (INIS)

    Field tests on the applicability of SIT to mosquito control have been conducted since the late 1950s. Early field experiments were conducted by releasing radiation-sterilized males. Methods of chemically sterilizing mosquitoes were also developed. Genetically altered strains which are partially sterile were also developed, studied and then used in field experiments. The earliest release experiments with mosquitoes were unsuccessful in introducing sterility into natural populations or reducing insect density, but identified problems and developed methodology. A summary of the releases conducted since the 1950s is given as background and then recent tests are reviewed in more detail where population control was achieved. The advances made in understanding the dynamics of field populations of mosquitoes when subjected to SIT are also reviewed. The problems associated with SIT for mosquito control - absolute density, growth rate, migration and others - are also discussed. (author)

  1. Transgenic mosquitoes for malaria control: progresses and challenges / Mosquitos transgênicos para o controle da malária: progressos e desafios

    Scientific Electronic Library Online (English)

    Luciano A., Moreira; Marcelo, Jacobs-Lorena.

    2003-12-01

    Full Text Available A malária mata milhões de pessoas a cada ano e as estratégias atuais de controle da doença, como inseticidas e drogas não têm sido tão eficientes. Por este motivo, novos meios para o combate à malária são de extrema importância. Avanços no estudo do mosquito vetor e sua interação com o parasito da m [...] alária fizeram os cientistas pensarem que é possível a manipulação genética dos mosquitos para torná-los vetores ineficientes. Neste artigo, revisamos os avanços na introdução de genes exógenos na linhagem germinativa de mosquitos, a caracterização de promotores específicos de certos tecidos, a identificação de produtos gênicos que bloqueiam o parasita no mosquito, bem como discutimos a recente geração de mosquitos transgênicos, menos eficientes na transmissão de malária. Enquanto muitos progressos foram obtidos, muitos anos de pesquisa são ainda necessários para que mosquitos transgênicos possam ser utilizados na natureza. Abstract in english Malaria kills millions of people every year and the current strategies to control the disease, such as insecticides and drugs have not been completely efficient. Because of that, novel means to fight against malaria are of utmost importance. Advances in the study of the mosquito vector and its inter [...] actions with the malaria parasite made scientists think that it is possible to genetically manipulate the mosquitoes to make them inefficient vectors. Here we review the advances on the introduction of foreign genes into the mosquito germ line, the characterization of tissue-specific promoters, the identification of gene products that block development of the parasite in the mosquito, and we discuss the recent generation of transgenic mosquitoes impaired for malaria transmission. While much progress has been made, many years of research are still needed before transgenic mosquitoes can be used in the field.

  2. Entomopathogenic fungi for mosquito control: A review

    OpenAIRE

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

    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...

  3. Mosquitoes

    Science.gov (United States)

    0000-00-00

    This tutorial is part of a series of entomological tutorials and covers the general biology and ecology of mosquitoes. The tutorial has 100 questions (50 in each of 2 tutorials); incorrect answers lead to additional information describing the correct answers. Covers all mosquito genera and their habitats, identification, life cycle, biology, and economic importance. Requires Windows. MAC is not supported. The cost for the tutorial CD is $15.

  4. Introduction and control of three invasive mosquito species in the Netherlands, July-October 2010

    OpenAIRE

    Scholte, E.J.; Den Hartog, W; Dik, M; Schoelitsz, B; Brooks, M.; Schaffner, F.; Foussadier, R; Braks, M; Beeuwkes, J.

    2010-01-01

    In July 2010, during routine mosquito surveillance inspections at companies that import used tires, three invasive species were found at five locations in the Netherlands: the yellow fever mosquito (Aedes aegypti), the Asian tiger mosquito (Ae. albopictus), and the American rock-pool mosquito (Ae. atropalpus). This is the first time that Ae. aegypti is reported from the Netherlands. Mosquito control was initiated one week after the first invasive mosquito was found, ...

  5. EFFICACY OF AGERATUM CONYZOIDES AGAINST THE CONTROL OF MOSQUITOES

    OpenAIRE

    Neetu Arya et al.

    2011-01-01

    Mosquitoes transmit serious human diseases causing millions of deaths every year. Phytochemistry has proven that there are potential mosquito control agents and also alternatives to synthetic insecticides. The present paper reports Ageratum conyzoides commonly known as Kubhi in Hindi of family Astereacae. The plant after proper identification was collected shade dried and powdered to the fine mesh size. 5 different concentrations were used against IInd and IVth instar of Anapheles stephensi. ...

  6. Genetic methods for control of mosquitoes and biting flies

    International Nuclear Information System (INIS)

    The earliest research efforts on using genetic methods for the control of mosquitoes and biting flies concentrated on the evaluation of the sterile insect technique (SIT). Several successful, but generally small scale, research efforts with mosquitoes clearly documented that either chemosterilized or radiation sterilized males were effective in causing a level of genetic load that would be sufficient for the reduction or eradication of natural populations of several species. Genetic sexing strains of several species of mosquitoes have been assembled, and this aspect of breeding specialty strains is not a limiting factor in the implementation of SIT. In the largest field experiment, conducted with Anopheles albimanus in El Salvador during the 1970s, a genetic sexing strain was used operationally in a factory that produced one million sterile males per day over a one year period. Technical problems that would require extensive research of a practical nature before the implementation of SIT for mosquito control involve primarily better means for the rearing, sterilization and distribution of the insects. A successful experiment was conducted to eliminate the stable fly on the island of St. Croix, the United States Virgin Islands, and since this work in the 1970s, genetic sexing strains have been developed. A considerable amount of effort was expended on the synthesis of chromosome aberrations for the control of mosquitoes. Although the results of experimental trials indigh the results of experimental trials indicated that aberration bearing insects could effectively inject a genetic load into the natural population, no large scale tests have ever been conducted to evaluate fully the real effectiveness of induced chromosomal aberrations. More recently, most of the research work in genetic control has been aimed at the use of recombinant DNA techniques for the development of new technology. All of these topics and an assessment of their value are discussed. (author). 30 refs

  7. Low- and High-Tech Approaches to Control Plasmodium Parasite Transmission by Anopheles Mosquitoes

    OpenAIRE

    Cirimotich, Chris M; April M. Clayton; George Dimopoulos

    2011-01-01

    Current efforts have proven inadequate to stop the transmission of Plasmodium parasites, and hence the spread of malaria, by Anopheles mosquitoes. Therefore, a novel arsenal of strategies for inhibiting Plasmodium infection of mosquitoes is urgently needed. In this paper, we summarize research on two approaches to malaria control, a low-tech strategy based on parasite inhibition by the mosquito's natural microflora, and a high-tech strategy using genetic modification of mosquitoes that render...

  8. Perspectives of people in Mali toward genetically-modified mosquitoes for malaria control

    OpenAIRE

    Famenini Shannon; Traore Mohamed M; Touré Mahamoudou B; Marshall John M; Taylor Charles E

    2010-01-01

    Abstract Background Genetically-modified (GM) mosquitoes have been proposed as part of an integrated vector control strategy for malaria control. Public acceptance is essential prior to field trials, particularly since mosquitoes are a vector of human disease and genetically modified organisms (GMOs) face strong scepticism in developed and developing nations. Despite this, in sub-Saharan Africa, where the GM mosquito effort is primarily directed, very little data is available on perspectives ...

  9. Fighting Arbovirus Transmission: Natural and Engineered Control of Vector Competence in Aedes Mosquitoes

    Directory of Open Access Journals (Sweden)

    Joy Kean

    2015-03-01

    Full Text Available Control of aedine mosquito vectors, either by mosquito population reduction or replacement with refractory mosquitoes, may play an essential role in the fight against arboviral diseases. In this review, we will focus on the development and application of biological approaches, both natural or engineered, to limit mosquito vector competence for arboviruses. The study of mosquito antiviral immunity has led to the identification of a number of host response mechanisms and proteins that are required to control arbovirus replication in mosquitoes, though more factors influencing vector competence are likely to be discovered. We will discuss key aspects of these pathways as targets either for selection of naturally resistant mosquito populations or for mosquito genetic manipulation. Moreover, we will consider the use of endosymbiotic bacteria such as Wolbachia, which in some cases have proven to be remarkably efficient in disrupting arbovirus transmission by mosquitoes, but also the use of naturally occurring insect-specific viruses that may interfere with arboviruses in mosquito vectors. Finally, we will discuss the use of paratransgenesis as well as entomopathogenic fungi, which are also proposed strategies to control vector competence.

  10. Large-scale control of mosquito vectors of disease

    International Nuclear Information System (INIS)

    By far the most important vector borne disease is malaria transmitted by Anopheles mosquitoes causing an estimated 300-500 million clinical cases per year and 1.4-2.6 million deaths, mostly in tropical Africa (WHO 1995). The second most important mosquito borne disease is lymphatic filariasis, but there are now such effective, convenient and cheap drugs for its treatment that vector control will now have at most a supplementary role (Maxwell et al. 1999a). The only other mosquito borne disease likely to justify large-scale vector control is dengue which is carried in urban areas of Southeast Asia and Latin America by Aedes aegypti L. which was also the urban vector of yellow fever in Latin America. This mosquito was eradicated from most countries of Latin America between the 1930s and 60s but, unfortunately in recent years, it has been allowed to re-infest and cause serious dengue epidemics, except in Cuba where it has been held close to eradication (Reiter and Gubler 1997). In the 1930s and 40s, invasions by An. gambiae Giles s.l., the main tropical African malaria vector, were eradicated from Brazil (Soper and Wilson 1943) and Egypt (Shousha 1947). It is surprising that greatly increased air traffic has not led to more such invasions of apparently climatically suitable areas, e.g., of Polynesia which has no anophelines and therefore no malaria. The above mentioned temporary or permanent eradications were achieved before the advent of DDT, using larvicidal methods (oadvent of DDT, using larvicidal methods (of a kind which would now be considered environmentally unacceptable) carried out by rigorously disciplined teams. MALARIA Between the end of the Second World War and the 1960s, the availability of DDT for spraying of houses allowed eradication of malaria from the Soviet Union, southern Europe, the USA, northern Venezuela and Guyana, Taiwan and the Caribbean Islands, apart from Hispaniola. Its range and intensity were also greatly reduced in China, India and South Africa and, at least temporarily, in Sri Lanka. In several Latin American countries much progress was made, but this has been reversed following the abandonment of DDT without any replacement being brought into use (Roberts et al. 1997). After eradication from the Soviet Union in the 1960s, malaria epidemics are now returning to Azerbaijan and Tadjikistan following the collapse of the health system and the descent into civil war (Nikolaeva 1996). In a few instances, unlooked-for eradication has been claimed to have occurred locally as a result of DDT house spraying of species which are strongly endophilic, i.e., with a strong tendency to rest in houses. There was much enthusiasm for SIT for mosquitoes in the 1960s and early 70s but it went into eclipse, largely for political reasons (Anonymous 1975). In the 70s, it was shown in various species of mosquito that chemically sterilised males, or males carrying translocations and a meiotic drive factor or cytoplasmically incompatible with the local population, could compete reasonably well for mates as shown by induction of sterility in the eggs laid by wild females (Lofgren et al. 1974, Grover et al. 1976a, b)

  11. Rationalizing Historical successes of malaria control in Africa in terms of mosquito resource availabilty management

    OpenAIRE

    Killeen, Gerry F.; Seyoum, Aklilu; KNOLS, BART G. J.

    2004-01-01

    Environmental management of mosquito resources is a promising approach with which to control malaria, but it has seen little application in Africa for more than half a century. Here we present a kinetic model of mosquito foraging for aquatic habitats and vertebrate hosts that allows estimation of malaria transmission intensity by defining the availability of these resources as the rate at which individual mosquitoes encounter and use them. The model captures historically observed responses of...

  12. EFFICACY OF AGERATUM CONYZOIDES AGAINST THE CONTROL OF MOSQUITOES

    Directory of Open Access Journals (Sweden)

    Neetu Arya et al.

    2011-12-01

    Full Text Available Mosquitoes transmit serious human diseases causing millions of deaths every year. Phytochemistry has proven that there are potential mosquito control agents and also alternatives to synthetic insecticides. The present paper reports Ageratum conyzoides commonly known as Kubhi in Hindi of family Astereacae. The plant after proper identification was collected shade dried and powdered to the fine mesh size. 5 different concentrations were used against IInd and IVth instar of Anapheles stephensi. Larvicidal and growth inhibitory activity of Ageratum conyzoides exhibited in the II and IVth instar larvae of the Anapheles stephensi. After 24 hours, LC50 value was determined using probit analysis method. It was notice that the LC50 value for IInd and IVth instar larvae were 238.65 and 228.54 ppm respectively. The result indicate that fourth instar larvae are more susceptible then second instar larvae .the result obtained suggest that bioactive compound of Ageratum conyzoides could be used in the search for new larvicidal compound of plant origin.

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

    Science.gov (United States)

    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

  14. Transfer of toxin genes to alternate bacterial hosts for mosquito control

    Scientific Electronic Library Online (English)

    Sergio, Orduz; Nora, Restrepo; Maria M, Patiño; William, Rojas.

    1995-02-01

    Full Text Available Mosquitoes are vector of serious human and animal diseases, such as malaria, dengue, yellow fever, among others. The use of biological control agents has provide an environmentally safe and highly specific alternative to the use of chemical insecticides in the control of vector borne diseases. Bacil [...] lus thuringiensis and B. sphaericus produce toxic proteins to mosquito larvae. Great progress has been made on the biochemical and molecular characterization of such proteins and the genes encoding them. Nevertheless, the low residuality of these biological insecticides is one of the major drawbacks. This article present some interesting aspects of the mosquito larvae feeding habits and review the attempts that have been made to genetically engineer microorganisms that while are used by mosquito larvae as a food source should express the Bacillus toxin genes in order to improve the residuality and stability in the mosquito breeding ponds.

  15. Transfer of toxin genes to alternate bacterial hosts for mosquito control

    Directory of Open Access Journals (Sweden)

    Sergio Orduz

    1995-02-01

    Full Text Available Mosquitoes are vector of serious human and animal diseases, such as malaria, dengue, yellow fever, among others. The use of biological control agents has provide an environmentally safe and highly specific alternative to the use of chemical insecticides in the control of vector borne diseases. Bacillus thuringiensis and B. sphaericus produce toxic proteins to mosquito larvae. Great progress has been made on the biochemical and molecular characterization of such proteins and the genes encoding them. Nevertheless, the low residuality of these biological insecticides is one of the major drawbacks. This article present some interesting aspects of the mosquito larvae feeding habits and review the attempts that have been made to genetically engineer microorganisms that while are used by mosquito larvae as a food source should express the Bacillus toxin genes in order to improve the residuality and stability in the mosquito breeding ponds.

  16. The use of bacterial larvicides in mosquito and black fly control programmes in Brazil

    OpenAIRE

    Regis Lêda; Silva Sinara B da; Melo-Santos Maria Alice V

    2000-01-01

    Bacillus spp. based larvides are increasingly replacing, with numerous advantages, chemical insecticides in programmes for controlling black fly and mosquito populations. Brazil was among the pioneers in adopting Bacillus thuringiensis israelensis (B.t.i) to control black flies. However, the major current mosquito control programme in Brazil, the Programme for Eradication of Aedes aegypti launched in 1997, only recently decided to replace temephos by B.t.i based larvicides, in the State of Ri...

  17. Biological control of mosquitoes in scrap tires in Brownsville, Texas, USA and Matamoros, Tamaulipas, Mexico.

    Science.gov (United States)

    Uejio, Christopher K; Hayden, Mary H; Zielinski-Gutierrez, Emily; Lopez, Jose Luis Robles; Barrera, Roberto; Amador, Manuel; Thompson, Gregory; Waterman, Stephen H

    2014-06-01

    Dengue periodically circulates in southern Texas and neighboring Tamaulipas, Mexico; thus, a closer examination of human and vector ecology at the northern limits of North American transmission may improve prevention activities. Scrap tires produce large mosquito populations and increase the risk of dengue transmission. Some households choose not to pay tire disposal fees, and many tires are illegally dumped in residential areas. Biological control may provide low-cost and environmentally friendly mosquito control. This pilot study evaluated the ability of Mesocyclops longisetus to reduce mosquito populations in existing residential scrap tire piles. Mosquito populations were measured by the number of all mosquito pupae within tires or adult Aedes aegypti and Ae. albopictus near piles. Mesocyclops longisetus treated piles did not significantly reduce total mosquito pupae (P = 0.07) in Matamoros, Mexico. The study also evaluated the efficacy of native Toxorhynchites moctezuma which preferentially colonized tire piles under vegetation cover in Brownsville, TX. Toxorhynchites moctezuma larvae significantly reduced total mosquito pupae, but the strength of control diminished over time. PMID:25102598

  18. A theoretical approach to predicting the success of genetic manipulation of malaria mosquitoes in malaria control

    OpenAIRE

    Koella Jacob C; Boëte Christophe

    2002-01-01

    Abstract Background Mosquitoes that have been genetically modified to better encapsulate the malaria parasite Plasmodium falciparum are being considered as a possible tool in the control of malaria. Hopes for this have been raised with the identification of genes involved in the encapsulation response and with advances in the tools required to transform mosquitoes. However, we have only very little understanding of the conditions that would allow such genes to spread in natural populations. M...

  19. Mathematical modeling of sterile insect technology for control of anopheles mosquito

    OpenAIRE

    Anguelov, Roumen; Dumont, Yves; Lubuma, Jean M. -s

    2012-01-01

    The Sterile Insect Technology (SIT) is a nonpolluting method of control of the invading insects that transmit disease. The method relies on the release of sterile or treated males in order to reduce the wild population of anopheles mosquito. We propose two mathematical models. The first model governs the dynamics of the anopheles mosquito. The second model, the SIT model, deals with the interaction between treated males and wild female anopheles. Using the theory of monotone op...

  20. Web mapping GIS: GPS under the GIS umbrella for Aedes species dengue and chikungunya vector mosquito surveillance and control

    Directory of Open Access Journals (Sweden)

    M. Palaniyandi

    2014-09-01

    Full Text Available The mosquito nuisance and the mosquito borne diseases have become major important challenging public health problems in India especially in the fast developing city like Pondicherry urban agglomeration. The Pondicherry government has been implemented full-fledged mosquito control measures, however, dengue and chikungunya epidemics was accelerating trend in Pondicherry for the recent years, and therefore, the directorate of public health, Pondicherry was requested vector control research centre (VCRC, to conduct a mosquito control evaluation survey. A team of field staff of VCRC headed by the author, Pondicherry, have conducted a detailed reconnaissance survey for collecting the site specifications of houses and the streetwise mosquito data for analyzing the density of vector mosquitoes in the wards / blocks and delineating the areas vulnerable to disease epidemics in the urban areas. The GPS GARMIN 12 XL was used to collect the field data. The ARC GIS 10.0 software was used to map the site locations (houses with mosquito’s data. The digital map of block boundary of Pondicherry was used for mapping purpose. A systematic grid sampling was applied to conduct a rapid survey for mapping Aedes species mosquito genic condition in the urban areas and the coordinates of sites of house information with breeding habitats positive in the grid sectors was collected using GPS, and the mean value of positive habitats was analyzed by quintiles method for mapping. The four blocks were selected for Aedes mosquito survey where the mosquito problem was identified as comparatively high, four numbers of wards were selected from each block, and the 40 number of houses was selected with 100 meter interval distance for mosquito breeding survey in the domestic and peripheral domestic areas in each wards. The problematic areas were identified, highlighted and recommended for web mapping GIS for Aedes mosquito surveillance continuously for monitoring the mosquito control measures in the Pondicherry urban areas and the other parts of the urban areas in the country.

  1. Perspectives of people in Mali toward genetically-modified mosquitoes for malaria control

    Directory of Open Access Journals (Sweden)

    Famenini Shannon

    2010-05-01

    Full Text Available Abstract Background Genetically-modified (GM mosquitoes have been proposed as part of an integrated vector control strategy for malaria control. Public acceptance is essential prior to field trials, particularly since mosquitoes are a vector of human disease and genetically modified organisms (GMOs face strong scepticism in developed and developing nations. Despite this, in sub-Saharan Africa, where the GM mosquito effort is primarily directed, very little data is available on perspectives to GMOs. Here, results are presented of a qualitative survey of public attitudes to GM mosquitoes for malaria control in rural and urban areas of Mali, West Africa between the months of October 2008 and June 2009. Methods The sample consisted of 80 individuals - 30 living in rural communities, 30 living in urban suburbs of Bamako, and 20 Western-trained and traditional health professionals working in Bamako and Bandiagara. Questions were asked about the cause of malaria, heredity and selective breeding. This led to questions about genetic alterations, and acceptable conditions for a release of pest-resistant GM corn and malaria-refractory GM mosquitoes. Finally, participants were asked about the decision-making process in their community. Interviews were transcribed and responses were categorized according to general themes. Results Most participants cited mosquitoes as one of several causes of malaria. The concept of the gene was not widely understood; however selective breeding was understood, allowing limited communication of the concept of genetic modification. Participants were open to a release of pest-resistant GM corn, often wanting to conduct a trial themselves. The concept of a trial was reapplied to GM mosquitoes, although less frequently. Participants wanted to see evidence that GM mosquitoes can reduce malaria prevalence without negative consequences for human health and the environment. For several participants, a mosquito control programme was preferred; however a transgenic release that satisfied certain requirements was usually acceptable. Conclusions Although there were some dissenters, the majority of participants were pragmatic towards a release of GM mosquitoes. An array of social and cultural issues associated with malaria, mosquitoes and genetic engineering became apparent. If these can be successfully addressed, then social acceptance among the populations surveyed seems promising.

  2. Eficacia del control de larvas de mosquitos (Diptera: Culicidae con peces larvívoros Effectiveness of the mosquito larvae control (Diptera: Cullicidae by larvivorous fish

    Directory of Open Access Journals (Sweden)

    Rigoberto Fimia Duarte

    2009-08-01

    Full Text Available OBJETIVO: se realizó un estudio de cohorte en los Consejos Populares de Báez y Guaracabulla, pertenecientes al municipio Placetas, provincia Villa Clara, para determinar la eficacia de 3 especies de peces fluviales: Gambusia punctata Poey, 1854, Gambusia puncticulata Poey, 1854 y Poecilia reticulata Peter, 1895, en el control de larvas de mosquitos en depósitos utilizados por la población para almacenar agua. MÉTODOS: la investigación se inició en el mes de abril de 2006 y culminó en mayo de 2007, se seleccionaron solo los tanques bajos (interior y exterior de las viviendas por ser más factibles de evaluar, se trabajó con una muestra de 1 740 depósitos que se dividieron en 2 grupos, los cuales se evaluaron por espacio de 1 año. RESULTADOS: el riesgo de encontrar focos de mosquitos fue superior en el grupo de depósitos que no estaban expuestos a la presencia de peces, la diferencia de riesgo permitió plantear que por cada 100 depósitos tratados con peces, se logró evitar 8 focos de mosquitos. CONCLUSIONES: los peces larvívoros constituyen una excelente alternativa contra las poblaciones larvales de culícidos en depósitos utilizados por la población para almacenar agua, que resulta un factor de protección ante la incidencia de focos de mosquitos.OBJECTIVE: a cohort study was conducted in People´s councils in Báez and Guaracabulla located in Placetas municipality, Villa Clara province, for the purpose of determining the effectiveness of three river fish called Gambusia punctata Poey, 1854, Gambusia puncticulata Poey, 1854 y Poecilia reticulata Peter, 1895 in the control of mosquito larvae inside water reservoirs used by the population. METHODS: the study began in April 2006 and ended May, 2007; the selected water tanks were placed inside and outside the houses since they were more easy to be evaluated. The sample covered 1 740 tanks divided into 2 groups and evaluated for one year. RESULTS: the risk of finding mosquito foci was higher in the group of reservoirs non-exposed to the action of fish; this difference allowed stating that 8 mosquito foci were prevented per every 100 reservoirs treated with fish. CONCLUSIONS: larvivorous fish are an excellent choice to treat Cullicidae larval populations existing in water tanks and also a protective factor against incidence of mosquito foci.

  3. Eficacia del control de larvas de mosquitos (Diptera: Culicidae) con peces larvívoros / Effectiveness of the mosquito larvae control (Diptera: Cullicidae) by larvivorous fish

    Scientific Electronic Library Online (English)

    Rigoberto, Fimia Duarte; Julio C, Castillo Cuenca; Omelio, Cepero Rodríguez; Edgar, Corona Santander; Ramón, González González.

    2009-08-01

    Full Text Available OBJETIVO: se realizó un estudio de cohorte en los Consejos Populares de Báez y Guaracabulla, pertenecientes al municipio Placetas, provincia Villa Clara, para determinar la eficacia de 3 especies de peces fluviales: Gambusia punctata Poey, 1854, Gambusia puncticulata Poey, 1854 y Poecilia reticulata [...] Peter, 1895, en el control de larvas de mosquitos en depósitos utilizados por la población para almacenar agua. MÉTODOS: la investigación se inició en el mes de abril de 2006 y culminó en mayo de 2007, se seleccionaron solo los tanques bajos (interior y exterior de las viviendas) por ser más factibles de evaluar, se trabajó con una muestra de 1 740 depósitos que se dividieron en 2 grupos, los cuales se evaluaron por espacio de 1 año. RESULTADOS: el riesgo de encontrar focos de mosquitos fue superior en el grupo de depósitos que no estaban expuestos a la presencia de peces, la diferencia de riesgo permitió plantear que por cada 100 depósitos tratados con peces, se logró evitar 8 focos de mosquitos. CONCLUSIONES: los peces larvívoros constituyen una excelente alternativa contra las poblaciones larvales de culícidos en depósitos utilizados por la población para almacenar agua, que resulta un factor de protección ante la incidencia de focos de mosquitos. Abstract in english OBJECTIVE: a cohort study was conducted in People´s councils in Báez and Guaracabulla located in Placetas municipality, Villa Clara province, for the purpose of determining the effectiveness of three river fish called Gambusia punctata Poey, 1854, Gambusia puncticulata Poey, 1854 y Poecilia reticula [...] ta Peter, 1895 in the control of mosquito larvae inside water reservoirs used by the population. METHODS: the study began in April 2006 and ended May, 2007; the selected water tanks were placed inside and outside the houses) since they were more easy to be evaluated. The sample covered 1 740 tanks divided into 2 groups and evaluated for one year. RESULTS: the risk of finding mosquito foci was higher in the group of reservoirs non-exposed to the action of fish; this difference allowed stating that 8 mosquito foci were prevented per every 100 reservoirs treated with fish. CONCLUSIONS: larvivorous fish are an excellent choice to treat Cullicidae larval populations existing in water tanks and also a protective factor against incidence of mosquito foci.

  4. Comparison of mosquito control programs in seven urban sites in Africa, the Middle East, and the Americas

    OpenAIRE

    Impoinvil, Daniel E.; Ahmad, Sajjad; Troyo, Adriana; Keating, Joseph; Githeko, Andrew K.; Mbogo, Charles M.; Kibe, Lydiah; Githure, John I.; Gad, Adel M.; Hassan, Ali N.; Orshan, Laor; Warburg, Alon; Caldero?n-arguedas, Olger; Sa?nchez-lori?a, Victoria M.; Velit-suarez, Rosanna

    2007-01-01

    Mosquito control programs at seven urban sites in Kenya, Egypt, Israel, Costa Rica, and Trinidad are described and compared. Site-specific urban and disease characteristics, organizational diagrams, and strengths, weaknesses, obstacles and threats (SWOT) analysis tools are used to provide a descriptive assessment of each mosquito control program, and provide a comparison of the factors affecting mosquito abatement. The information for SWOT analysis is collected from surveys, focus group discu...

  5. The effects of zooprophylaxis and other mosquito control measures against malaria in Nouna, Burkina Faso

    Directory of Open Access Journals (Sweden)

    Sié Ali

    2009-12-01

    Full Text Available Abstract Background In the absence of large scale, organized vector control programmes, individual protective measures against mosquitoes are essential for reducing the transmission of diseases like malaria. Knowledge of the types and effectiveness of mosquito control methods used by households can aid in the development and promotion of preventive measures. Methods A matched, population-based case control study was carried out in the semi-urban region of Nouna, Burkina Faso. Surveys and mosquito captures were conducted for each participating household. Data were analysed using conditional logistic regression and Pearson's product-moment correlations. Results In Nouna, Burkina Faso, the main types of reported mosquito control measures used included sleeping under bed nets (insecticide-treated and untreated and burning mosquito coils. Most of the study households kept animals within the compound or house at night. Insecticide house sprays, donkeys, rabbits and pigs were significantly associated with a reduced risk of malaria only in univariate analyses. Conclusion Given the conflicting results of the effects of zooprophylaxis from previous studies, other community-based preventive measures, such as bed nets, coils and insecticide house-spraying, may be of more benefit.

  6. The use of bacterial larvicides in mosquito and black fly control programmes in Brazil

    Scientific Electronic Library Online (English)

    Lêda, Regis; Sinara B da, Silva; Maria Alice V, Melo-Santos.

    Full Text Available Bacillus spp. based larvides are increasingly replacing, with numerous advantages, chemical insecticides in programmes for controlling black fly and mosquito populations. Brazil was among the pioneers in adopting Bacillus thuringiensis israelensis (B.t.i) to control black flies. However, the major c [...] urrent mosquito control programme in Brazil, the Programme for Eradication of Aedes aegypti launched in 1997, only recently decided to replace temephos by B.t.i based larvicides, in the State of Rio de Janeiro. In the last decade, works developed by research groups in Brazilian institutions have generated a significant contribution to this subject through the isolation of B. sphaericus new strains, the development of new products and the implementation of field trials of Bacillus efficacy against mosquito species under different environmental conditions.

  7. The use of bacterial larvicides in mosquito and black fly control programmes in Brazil

    Directory of Open Access Journals (Sweden)

    Regis Lêda

    2000-01-01

    Full Text Available Bacillus spp. based larvides are increasingly replacing, with numerous advantages, chemical insecticides in programmes for controlling black fly and mosquito populations. Brazil was among the pioneers in adopting Bacillus thuringiensis israelensis (B.t.i to control black flies. However, the major current mosquito control programme in Brazil, the Programme for Eradication of Aedes aegypti launched in 1997, only recently decided to replace temephos by B.t.i based larvicides, in the State of Rio de Janeiro. In the last decade, works developed by research groups in Brazilian institutions have generated a significant contribution to this subject through the isolation of B. sphaericus new strains, the development of new products and the implementation of field trials of Bacillus efficacy against mosquito species under different environmental conditions.

  8. MAN, MOSQUITOES AND MICROBES.

    Science.gov (United States)

    SCHOONOVER, ROBERT A.

    THE CONTROL OF MOSQUITOES IS A MATTER OF INCREASING CONCERN IN THE STATE OF FLORIDA. A BRIEF DESCRIPTION OF THE LIFE CYCLE, VARIOUS SPECIES, CONTROL, AND DESCRIPTION OF DISEASES TRANSMITTED BY THE MOSQUITO WAS PRESENTED. THE ARTICLE CONCLUDED THAT MOSQUITO CONTROL IS NOT ONLY A HEALTH PROBLEM, BUT ALSO A MATTER OF IMPROVED ECONOMICS IN RELATION TO…

  9. Recasting the theory of mosquito-borne pathogen transmission dynamics and control.

    Science.gov (United States)

    Smith, David L; Perkins, T Alex; Reiner, Robert C; Barker, Christopher M; Niu, Tianchan; Chaves, Luis Fernando; Ellis, Alicia M; George, Dylan B; Le Menach, Arnaud; Pulliam, Juliet R C; Bisanzio, Donal; Buckee, Caroline; Chiyaka, Christinah; Cummings, Derek A T; Garcia, Andres J; Gatton, Michelle L; Gething, Peter W; Hartley, David M; Johnston, Geoffrey; Klein, Eili Y; Michael, Edwin; Lloyd, Alun L; Pigott, David M; Reisen, William K; Ruktanonchai, Nick; Singh, Brajendra K; Stoller, Jeremy; Tatem, Andrew J; Kitron, Uriel; Godfray, H Charles J; Cohen, Justin M; Hay, Simon I; Scott, Thomas W

    2014-04-01

    Mosquito-borne diseases pose some of the greatest challenges in public health, especially in tropical and sub-tropical regions of the world. Efforts to control these diseases have been underpinned by a theoretical framework developed for malaria by Ross and Macdonald, including models, metrics for measuring transmission, and theory of control that identifies key vulnerabilities in the transmission cycle. That framework, especially Macdonald's formula for R0 and its entomological derivative, vectorial capacity, are now used to study dynamics and design interventions for many mosquito-borne diseases. A systematic review of 388 models published between 1970 and 2010 found that the vast majority adopted the Ross-Macdonald assumption of homogeneous transmission in a well-mixed population. Studies comparing models and data question these assumptions and point to the capacity to model heterogeneous, focal transmission as the most important but relatively unexplored component in current theory. Fine-scale heterogeneity causes transmission dynamics to be nonlinear, and poses problems for modeling, epidemiology and measurement. Novel mathematical approaches show how heterogeneity arises from the biology and the landscape on which the processes of mosquito biting and pathogen transmission unfold. Emerging theory focuses attention on the ecological and social context for mosquito blood feeding, the movement of both hosts and mosquitoes, and the relevant spatial scales for measuring transmission and for modeling dynamics and control. PMID:24591453

  10. Mosquito, egg raft (image)

    Science.gov (United States)

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

  11. Novel Acetylcholinesterase Target Site for Malaria Mosquito Control

    OpenAIRE

    Pang, Yuan-Ping

    2006-01-01

    Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs) in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae) AChE (AgAChE) reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, res...

  12. Use of Expanded Polystyrene (EPS and Shredded Waste Polystyrene (SWAP Beads for Control of Mosquitoes

    Directory of Open Access Journals (Sweden)

    A Soltani

    2008-12-01

    Full Text Available Background: Mosquitoes transmit several diseases to human. There are several measures for control of larvae. As part of Integrated Vector Management (IVM program, the utility of floating layers of polystyrene beads (EPS is a po­ten­tial alternative in habitats of mosquito larva. EPS beads prevent oviposition of mosquito as well as killing the im­ma­ture stages by forming a tick layer on the water surface.  They are cheap, environmentally safe and do not need fre­quent application and remain on the surface of water for long time. The objective of the current study was to asses the effectiveness of two types of polystyrene beads of (EPS and (SWAP for control of mosquito larvae under labo­ra­tory conditions."nMethods: Anopheles stephensi and Culex quinquefasciatus were used for experimental purposes. In each tray 250 lar­vae of late 3rd and early 4th instars were introduced. The experiment was conducted on 4 replicates for An. ste­phensi, Cu. quinquefasciatus and combination of both. Emerging of adult mosquitoes were calculated every day until the end of experiments."nResults: Mortality rate and Inhibition of Emerge (IE for Cu. quinquefasciatus, An. stephensi and combination of both spe­cies was 97.8%, 100% and 99.07%, respectively using EPS. In average, EPS was able to kill 98.9% of lar­vae. The fig­ures with SWAP were 63%, 91.05% and 72.65%, respectively. The average mortality for mosquitoes was 75.57%"nConclusion: EPS and SWAP beads can be very effective and practical for elimination of An. stephensi and Cx. quinquefas­ciatus under the laboratory conditions.

  13. Synthesis of silver nanoparticles from Azadirachta indica--a most effective method for mosquito control.

    Science.gov (United States)

    Poopathi, Subbiah; De Britto, Lourduraj John; Praba, V Lakshmi; Mani, C; Praveen, M

    2015-02-01

    Mosquitoes transmit major communicable diseases such as dengue, malaria, filariasis, Japanese encephalitis, chikungunya, and so on. Vector control is important in epidemic disease situations as there is an urgent need to develop new and improved mosquito control methods that are economical and effective yet safe for non-targeted organisms. In the present study, silver nanoparticles (AgNPs) were synthesized from the aqueous leaf extract of neem plant (Azadirachta indica), and their effects on mosquito vectors (Aedes aegypti and Culex quinquefasciatus) were assessed. The synthesised AgNPs were characterized by UV-vis spectroscopy, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD). The nanoparticles have maximum absorption at 442?±?1.5 nm with an average size of 41-60 nm. The XRD data showed six well-defined diffraction peaks, corresponding to a relative intensity of the crystal structure of metallic silver 36.42, 100.00, 53.70, 14.20, 16.05, and 6.79, respectively. The FT-IR data showed strong prominent peaks in different ranges, reflecting its complex nature. The mosquito larvae were exposed to varying concentrations of AgNPs synthesized from the neem leaves under investigation (0.07-25 mg/l) for 24 h; this revealed larvicidal activity of AgNPs with LC50 and LC90 values of 0.006 and 0.04 mg/l for A. aegypti, respectively. Further, the LC50 and LC90 values were also identified as 0.047 and 0.23 mg/l for Cx. quinquefasciatus, respectively. The result obtained from this study presents biosynthesized silver nanoparticle from A. indica as the biolarvicidal agent with the most potential for mosquito control. PMID:25226837

  14. Cost-effectiveness of Novel System of Mosquito Surveillance and Control, Brazil

    OpenAIRE

    Pepin, Kim M.; Marques-toledo, Cecilia; Scherer, Luciano; Morais, Maira M.; Ellis, Brett; Eiras, Alvaro E.

    2013-01-01

    Of all countries in the Western Hemisphere, Brazil has the highest economic losses caused by dengue fever. We evaluated the cost-effectiveness of a novel system of vector surveillance and control, Monitoramento Inteligente da Dengue (Intelligent Dengue Monitoring System [MID]), which was implemented in 21 cities in Minas Gerais, Brazil. Traps for adult female mosquitoes were spaced at 300-m intervals throughout each city. In cities that used MID, vector control was conducted specifically at h...

  15. Recasting the theory of mosquito-borne pathogen transmission dynamics and control

    OpenAIRE

    SMITH, DAVID L.; Perkins, T. Alex; Reiner, Robert C.; Christopher M. Barker; Niu, Tianchan; Chaves, Luis Fernando; Ellis, Alicia M; George, Dylan B.; Le Menach, Arnaud; Pulliam, Juliet R. C.; Bisanzio, Donal; BUCKEE, CAROLINE; Chiyaka, Christinah; Cummings, Derek A. T.; Garcia, Andres J.

    2014-01-01

    Mosquito-borne diseases pose some of the greatest challenges in public health, especially in tropical and sub-tropical regions of the world. Efforts to control these diseases have been underpinned by a theoretical framework developed for malaria by Ross and Macdonald, including models, metrics for measuring transmission, and theory of control that identifies key vulnerabilities in the transmission cycle. That framework, especially Macdonald's formula for R0 and its entomologica...

  16. Recasting the theory of mosquito-borne pathogen transmission dynamics and control

    OpenAIRE

    SMITH, DAVID L.; Perkins, T. Alex; Reiner, Robert C.; Christopher M. Barker; Niu, Tianchan; Chaves, Luis Fernando; Ellis, Alicia M; George, Dylan B.; Le Menach, Arnaud; Pulliam, Juliet R. C.; Bisanzio, Donal; BUCKEE, CAROLINE; Chiyaka, Christinah; Cummings, Derek A. T.; Garcia, Andres J.

    2014-01-01

    Mosquito-borne diseases pose some of the greatest challenges in public health, especially in tropical and sub-tropical regions of the world. Efforts to control these diseases have been underpinned by a theoretical framework developed for malaria by Ross and Macdonald, including models, metrics for measuring transmission, and theory of control that identifies key vulnerabilities in the transmission cycle. That framework, especially Macdonald's formula for R0 and its entomological derivative, v...

  17. INFRAVEC: research capacity for the implementation of genetic control of mosquitoes.

    Science.gov (United States)

    Crisanti, Andrea

    2013-12-01

    Mosquitoes represent a major and global cause of human suffering due to the diseases they transmit. These include parasitic diseases, i.e. malaria and filariasis, and viral infections such as dengue, encephalitis, and yellow fever. The threat of mosquito-borne diseases is not limited to tropical and subtropical regions of the world. Trade and climate changes have opened new niches to tropical vectors in temperate areas of the world, thus putting previously unaffected regions at risk of disease transmission. The most notable example is the spread of Aedes species, particularly the Asian tiger mosquito Aedes albopictus to southern Europe (reviewed in Ref. 1). Endogenous cases of vector-borne diseases including West Nile fever, chikungunya, and dengue are frequently being reported, highlighting the increased risk of tropical diseases for the European population. Typically, vector control measures targetting mosquitoes are in most cases carried with the use of insecticides. This approach has a number of limitations that constrain their effectiveness. Lack of resources, inadequate logistics, and the insurgence of insecticide resistance are some of the problems encountered in disease-endemic countries (DECs). More recently in Africa, the widespread use of insecticide-treated bed nets has caused a dramatic reduction in malaria mortality and morbidity. Bed nets however are a temporary solution, a testimony of the failure to implement area-wide control measures aimed at eradicating malaria. US and Europe, with well-developed economies, have also failed to control the spread of mosquito vectors, particularly Aedes species. This alarming situation clearly speaks for the need to expand the knowledge on mosquito vectors and for the urgency of developing and validating novel biological and genetic control measures that overcome the limitations of current insecticide-based approaches. During the last 10 years, significant advances have been made in understanding the biology, the genetics, and the ecology of Anopheles and Aedes mosquitoes paralleled by the development of new molecular tools for investigating gene function and mosquito ability to transmit parasite and viral diseases. They offer a compelling opportunity to design and validate new genetic vector control measures. The size and the complexity of this undertaking require a high level of capacity, effort, and technological platforms. No laboratory--or even institution--has the resources, the infrastructure capacity, and the expertise to accomplish this task alone. INFRAVEC addresses the need of the scientific community to share facilities and integrate cutting-edge knowledge and technologies that are not readily accessible but nevertheless critical to exploit genetic and genomic information in the effort to control mosquito-borne diseases. Its objective is to provide laboratories that currently operate individually with limited coordination and little sharing of technologies, with the collective research capacity of the laboratories forming the core project infrastructure. INFRAVEC has provided resources to 31 institutions from European and African countries to enhance collaborative links, to execute joint research activity, and most importantly to enable individual researchers (from PhD students to established academics) to carry complex experimental activities by assigning research packages or ‘infrastructure access’ to be executed in the laboratory facilities and infrastructures of INFRAVEC. I report here on the overall activities of INFRAVEC and its impact on the scientific community with the purpose to initiate a dialogue with all stakeholders on its future evolution. PMID:24428829

  18. Persistent oscillations and backward bifurcation in a malaria model with varying human and mosquito populations: implications for control.

    Science.gov (United States)

    Ngonghala, Calistus N; Teboh-Ewungkem, Miranda I; Ngwa, Gideon A

    2015-06-01

    We derive and study a deterministic compartmental model for malaria transmission with varying human and mosquito populations. Our model considers disease-related deaths, asymptomatic immune humans who are also infectious, as well as mosquito demography, reproduction and feeding habits. Analysis of the model reveals the existence of a backward bifurcation and persistent limit cycles whose period and size is determined by two threshold parameters: the vectorial basic reproduction number [Formula: see text], and the disease basic reproduction number [Formula: see text], whose size can be reduced by reducing [Formula: see text]. We conclude that malaria dynamics are indeed oscillatory when the methodology of explicitly incorporating the mosquito's demography, feeding and reproductive patterns is considered in modeling the mosquito population dynamics. A sensitivity analysis reveals important control parameters that can affect the magnitudes of [Formula: see text] and [Formula: see text], threshold quantities to be taken into consideration when designing control strategies. Both [Formula: see text] and the intrinsic period of oscillation are shown to be highly sensitive to the mosquito's birth constant [Formula: see text] and the mosquito's feeding success probability [Formula: see text]. Control of [Formula: see text] can be achieved by spraying, eliminating breeding sites or moving them away from human habitats, while [Formula: see text] can be controlled via the use of mosquito repellant and insecticide-treated bed-nets. The disease threshold parameter [Formula: see text] is shown to be highly sensitive to [Formula: see text], and the intrinsic period of oscillation is also sensitive to the rate at which reproducing mosquitoes return to breeding sites. A global sensitivity and uncertainty analysis reveals that the ability of the mosquito to reproduce and uncertainties in the estimations of the rates at which exposed humans become infectious and infectious humans recover from malaria are critical in generating uncertainties in the disease classes. PMID:24992885

  19. Alternative methodologies in the integrated control of urban mosquito larvae: water surface obliteration techniques

    Directory of Open Access Journals (Sweden)

    Roger Eritja

    2012-12-01

    Full Text Available The public health risk associated to mosquitoes has increased in Spain by the introduction of the Asian Tiger Mosquito (Aedes albopictus which is a well-known disease vector. Integrated control methodologies basically rely on larviciding by weekly applications of microbial biocides that have no residual effect. In some special cases, such as swimming pools in abandoned estates, this weekly schedule cannot be achieved due to difficulties of access and operational reasons. In these circumstances, there are no appropriate biocidal options except for Insect Growth Regulators (IGR, which do not provide more than a few weeks of residual efficiency. We present here the practical application of a well-known technique for controlling mosquito larvae in urban environments by altering the water/air interface. The adding to the water surface of a thick layer of beads made from inert, floating materials is described. The layer of beads impedes oviposition and adversely affects the breathing of the larvae. This technique avoids the regular application of chemical pesticides, as well as providing improved sustainability and higher efficiency times. Caution notes and side effects are also discussed.

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

    Science.gov (United States)

    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

  1. Controle de mosquitos com base em larvicidas no Estado do Rio Grande do Sul, Brasil: a escolha do agente de controle Mosquito control based on larvicides in the State of Rio Grande do Sul, Brazil: choice of the control agent

    OpenAIRE

    Ruas-neto, Anto?nio L.; Silveira, Sydnei M.; Colares, Evandro Ricardo Da C.

    1994-01-01

    Desenvolveu-se neste estudo uma comparação entre larvicidas químicos e biológicos usados em programas de controle de mosquitos no Rio Grande do Sul. Em bioensaios de laboratório contra Culex quinquefasciatus constatou-se que as formulações biológicas líquidas Vectobac 12 AS e Teknar 3000 (Bacillus thuringiensis israelensis), ABG 6262 líquido e em pó (B. sphaericus 2362), foram altamente eficazes. Também as formulações experimentais de B. thuringiensis israelensis produzidas em l...

  2. Geostatistical evaluation of integrated marsh management impact on mosquito vectors using before-after-control-impact (BACI design

    Directory of Open Access Journals (Sweden)

    Dempsey Mary E

    2009-06-01

    Full Text Available Abstract Background In many parts of the world, salt marshes play a key ecological role as the interface between the marine and the terrestrial environments. Salt marshes are also exceedingly important for public health as larval habitat for mosquitoes that are vectors of disease and significant biting pests. Although grid ditching and pesticides have been effective in salt marsh mosquito control, marsh degradation and other environmental considerations compel a different approach. Targeted habitat modification and biological control methods known as Open Marsh Water Management (OMWM had been proposed as a viable alternative to marsh-wide physical alterations and chemical control. However, traditional larval sampling techniques may not adequately assess the impacts of marsh management on mosquito larvae. To assess the effectiveness of integrated OMWM and marsh restoration techniques for mosquito control, we analyzed the results of a 5-year OMWM/marsh restoration project to determine changes in mosquito larval production using GIS and geostatistical methods. Methods The following parameters were evaluated using "Before-After-Control-Impact" (BACI design: frequency and geographic extent of larval production, intensity of larval production, changes in larval habitat, and number of larvicide applications. The analyses were performed using Moran's I, Getis-Ord, and Spatial Scan statistics on aggregated before and after data as well as data collected over time. This allowed comparison of control and treatment areas to identify changes attributable to the OMWM/marsh restoration modifications. Results The frequency of finding mosquito larvae in the treatment areas was reduced by 70% resulting in a loss of spatial larval clusters compared to those found in the control areas. This effect was observed directly following OMWM treatment and remained significant throughout the study period. The greatly reduced frequency of finding larvae in the treatment areas led to a significant decrease (~44% in the number of times when the larviciding threshold was reached. This reduction, in turn, resulted in a significant decrease (~74% in the number of larvicide applications in the treatment areas post-project. The remaining larval habitat in the treatment areas had a different geographic distribution and was largely confined to the restored marsh surface (i.e. filled-in mosquito ditches; however only ~21% of the restored marsh surface supported mosquito production. Conclusion The geostatistical analysis showed that OMWM demonstrated considerable potential for effective mosquito control and compatibility with other natural resource management goals such as restoration, wildlife habitat enhancement, and invasive species abatement. GPS and GIS tools are invaluable for large scale project design, data collection, and data analysis, with geostatistical methods serving as an alternative or a supplement to the conventional inference statistics in evaluating the project outcome.

  3. Fishes of District Sundargarh, Orissa, with special reference to their potential in mosquito control.

    Science.gov (United States)

    Yadav, R S; Padhan, K; Sharma, V P

    1992-12-01

    An extensive fish fauna survey was carried out in Sundargarh, a malaria-endemic district in Orissa, during 1988 to 1990 to identify and evaluate the indigenous larvivorous fishes for mosquito control. In all, 57 species belonging to 19 families under 6 orders were found in the local water bodies. On laboratory evaluation against anopheline and culicine larvae, six potential larvivorous fishes, viz. Aplocheilus panchax, Oryzias melastigma, Oreochromis mossambicus, Gambusia affinis, Danio (B.) rerio and Esomus danricus were selected. Feasibility of mass multiplication of these fishes in village ponds for operational use is being studied. PMID:1363317

  4. A novel cost-effective medium for the production of Bacillus thuringiensis subsp. israelensis for mosquito control.

    Science.gov (United States)

    Poopathi, Subbiah; Archana, B

    2012-03-01

    Bacillus thuringiensis subsp. israelensis (Bti) has been used for mosquito-control programmes the world-wide. Indeed, the large-scale production of Bti for mosquito control is very expensive due to the high cost of its culture. In the present study, we attempted to widen the scope in developing cost-effective culture medium for Bti production, based on the raw materials available on the biosphere, including coconut cake powder, CCP (Cocos nucifera), neem cake powder, NCP (Azadirachta indica) and groundnut cake powder, GCP (Arachis hypogea). Among these raw materials, the biomass production of Bti, sporulation and toxin synthesizing from 'CCP' in combination with mineral salt (MnCl(2)) was comfortably satisfactory. Bioassays with mosquito species (Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti) and field trials were also satisfactory. The present investigation suggests that coconut cake-based culture medium can be used as an alternative for industrial production of Bti in mosquito-control programme. Therefore, the study is very important from the point of effective production of Bti from cost-effective culture medium for the control of mosquito vectors. PMID:22543607

  5. Controle de mosquitos com base em larvicidas no Estado do Rio Grande do Sul, Brasil: a escolha do agente de controle Mosquito control based on larvicides in the State of Rio Grande do Sul, Brazil: choice of the control agent

    Directory of Open Access Journals (Sweden)

    Antônio L. Ruas-Neto

    1994-06-01

    Full Text Available Desenvolveu-se neste estudo uma comparação entre larvicidas químicos e biológicos usados em programas de controle de mosquitos no Rio Grande do Sul. Em bioensaios de laboratório contra Culex quinquefasciatus constatou-se que as formulações biológicas líquidas Vectobac 12 AS e Teknar 3000 (Bacillus thuringiensis israelensis, ABG 6262 líquido e em pó (B. sphaericus 2362, foram altamente eficazes. Também as formulações experimentais de B. thuringiensis israelensis produzidas em laboratórios brasileiros foram consideradas adequadas. Entre as formulações químicas, os compostos piretróides Pirisa e K-Othrine produziram resultados melhores do que os organo-fosforados Lebaycid e Abate. Estes últimos produziram respostas dez vezes mais fracas do que o previsto em outros estudos. Em condições de campo, a dose de 1250 mg/m² para as formulações biológicas foi considerada adequada para a rotina das aplicações, porque permite superar as influências físicas do meio sobre os resultados. Somente as formulações de B. sphaericus produziram interrupções nas reinfestações dos focos de culicídeos observados. Períodos de até 39 semanas sem reinfestações foram observados em focos naturais e de um mês sem sobrevivência foi observado em tanques, onde procedia-se a reinfestação artificial. Este estudo sugere que as alternativas biológicas devem ser consideradas em programas de controle de mosquitos. Elas podem superar os problemas de resistência e eliminação, bem como da ausência de efeito residual nas aplicações de larvicidas.A comparison between chemical and biological larvicides in routine operations against mosquitoes in Rio Grande do Sul State was carried out in this study. In laboratory bioassays against Culex quinquefasciatus, biological formulations Vectobac 12 AS and Teknar 3000 (Bacillus thuringiensis israelensis as well as ABG 6262 (B. sphaericus 2362, both in liquid and powder form, were highly effective. Locally produced B.thuringiensis israelensis, formulations also yielded good results. Among chemical larvicides, pyrethroid compounds Pirisa and K-Othrine yielded better results than the organophosphates Lebaycid and Abate. These last formulations yielded responses ten weaker than predicted in other studies. Under field conditions, a dose of 1250 mg/m² for biological formulations was considered adequate for routine application because at this level it is possible to overcome physical influences on results. Only B.sphaericus preparations caused important disruption of mosquito colonization in active breeding sites. Up to 39 weeks were tabulated without complete colonization in natural conditions and one month in artificially colonized tanks. This study suggests that biological alternatives should be considered in mosquito control programs. They may be a solution to such problems as resistance to larvicides, elimination of natural enemies, and short-lasting effects of applications.

  6. Biochemical, molecular and microscopic studies on mosquitoes with special emphasis on Wolbachia infections, diagnostic assessment of Dengue viruses and biological control of Dengue vectors

    OpenAIRE

    Mahilum, Mila

    2003-01-01

    Mosquitoes are threatening the human population as vectors of debilitating diseases such as malaria, dengue, yello and west nile fever as well as lymphatic filariasis. The knowledge on the biology of mosquitoes, pathogens and parasites transmitted by them is essential for a better control of both insects and diseases they are transmitting. This dissertation aims to increase the knowldege on the biology of vector mosquitoes as well as the pathogens. The research includes the following topics, ...

  7. Use of granulated fertilizers with Actellic EC 50 insecticide in the control of mosquito larvae.

    Science.gov (United States)

    Rettich, F

    1981-01-01

    Granulated fertilizers [ammonium nitrate, synthetic fertilizer] were used as carriers to prepare an insecticide granulate suitable for the control of Aedes cantans and Aedes vexans mosquito larvae under field conditions. The insecticide granulate was obtained by mixing 1 volume unit of Actellic EC 50 with 50 volume units of fertilizer. The optimal dose required to ensure and effective control of Aedes mosquito larvae was 2--5 g of granulate per 1 m3 of water [i.e. 2--5 kg/ha per each 1- cm depth of water] in hatching areas with a relatively clean water or during periods of slow larval growth and development, and 10 g of granulate per 1 m3 of water for hatching places polluted with organic substances or for periods of accelerated larval growth during summer months. The described Actellic EC 50 application practice ensures a complete survival of numerous non-target water organisms, including Tubifex species, Rhynchelmis species, molluscs, flatworms [Turbellaria], Asellus aquaticus, water mites [Hydrachna sp.] water striders (Gerris lacustris] and Dixella species larvae]. PMID:6262402

  8. Aerial and tidal transport of mosquito control pesticides into the Florida Keys National Marine Sanctuary

    International Nuclear Information System (INIS)

    This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS). The study monitored the distribution and persistente of two mosquito adulticides, permethrin and dibrom (naled), during three separate routine applications by the Florida Keys Mosquito Control District. The approach was to determine if toxic concentrations of the pesticides entered the FKNMS by aerial drift or tidal transport. The amount of pesticide entering the FKNMS by way of aerial drift was monitored by collection on glass fiber filter pads, set on floats in a grid pattern on either side of the FKNMS. Permethrin was recovered from filter pads on the leeward side for each of the three applications, ranging from 0.5 to 50.1 ?g/m2 throughout the study. Tidal current transport was monitored by collection of surface and subsurface water samples at each grid site. Tidal transport of naled and dichlorvos (naled degradation product) was apparent in the adjacent waters of the FKNMS. These compounds were detected in subsurface, offshore water at 0.1 to 0.6 gg/l, 14 hr after application. Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 ?g/1 were found in surface water from the canal system adjacent to the application route. Comparison of the observed environmental concentrations with toxicity data (permetoncentrations with toxicity data (permethrin LC-50, 96 hr for Mysidopsis bahia = 0.02 ?g/1) indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas

  9. Biorational insecticides for control of mosquitoes and black flies in Sinaloa

    Directory of Open Access Journals (Sweden)

    Cipriano García Gutiérrez

    2012-09-01

    Full Text Available In Sinaloa Mexico the presence of mosquitoes is a important health problem, and each spring-summer season appear several species which include: Aedes aegypti (Linneus, Anopheles albimanus (Wiedemann, Culex quinquefasciatus (Say and black flies of the Simulidae family. The control of larvae and adults of these insects are usually performed with chemical insecticides, so the use of biorational insecticides for control of these insects is novel, due to that have low environment impact. The objective of this work is to give known to the different biorational insecticides and their biological effects (inhibitor, insect repellent, larvicide, adulticide, that can be used to combat to different development stages of these insects. As well as show the progress of a study on the effectiveness of neem extracts, garlic, cinnamon, albahaca and cypermethrin at low doses (0.25,0.5 and 1ml/L, for control of larvae and adults of black flies in the unicipality of El Fuerte, Sinaloa. By the mode of action, the biorational that can doing use for the control of theseinsects were: Spinosad, and Bacillus thuringiensis (Berliner var. israeliensis for larvae control, Spinosad and Beauveria bassiana (Vuill. for adults; as well as extracts of neem, garlic, cinnamon and albahaca for both stages. The preliminary results of the study showed that the effectiveness application in tourist sites, through aerial spraying of cypermethrin at low doses and the plants extracts, allow low the index of larvae and infestation of mosquitoes and blackflies, decreasing the discomfort caused by these insects in the place of study.

  10. Economic evaluation of area-wide pest management program to control asian tiger mosquito in New Jersey

    Science.gov (United States)

    Area-wide pest management (AWPM) is recommended to control urban mosquitoes, such as Aedes albopictus, which limit outdoor activities. While several evaluations of effectiveness exist, information on costs is lacking. Economic evaluation of such a program is important to help inform policy makers an...

  11. A critical review of ultralow-volume aerosols of insecticide applied with vehicle-mounted generators for adult mosquito control.

    Science.gov (United States)

    Mount, G A

    1998-09-01

    This review of ultralow-volume (ULV) ground aerosols for adult mosquito control includes discussion on application volume, aerosol generators, droplet size, meteorology, swath, dispersal speed, assay methods, insecticide efficacy, and nontarget effects. It summarizes the efficacy of ULV insecticidal aerosols against many important pest and disease-bearing species of mosquitoes in a wide range of locations and habitats in the United States and in some countries of Asia and the Americas. Fourteen conclusions were drawn from the review. 1) ULV ground aerosol applications of insecticide are as efficacious against adult mosquitoes as high- or low-volume aerosols. 2) ULV aerosols with an optimum droplet size spectrum can be produced by several types of nozzles including vortex, pneumatic, and rotary. Droplet size of a particular insecticide formulation is dependent primarily on nozzle air pressure or rotation speed and secondarily on insecticide flow rate. 3) Label flow rates of insecticide for ULV aerosol application can be delivered accurately during routine operations with speed-correlated metering systems within a calibrated speed range, usually not exceeding 20 mph. 4) The most economical and convenient method of droplet size determination for ULV aerosols of insecticide is the waved-slide technique. 5) The efficacy of ULV ground aerosols against adult mosquitoes is related to droplet size because it governs air transport and impingement. The optimum droplet size for mosquito adulticiding is 8-15 microns volume median diameter (VMD) on the basis of laboratory wind-tunnel tests and field research with caged mosquitoes. 6) In general, ULV aerosols should be applied following sunset when mosquitoes are active and meteorological conditions are favorable for achieving maximum levels of control. Application can be made during daytime hours when conditions permit, but rates may have to be increased. The critical meteorological factors are wind velocity and direction, temperature, and atmospheric stability and turbulence. 7) Maximum effective swaths are obtained with aerosols in the optimum VMD range during favorable meteorological conditions in open to moderately open terrain. The insecticide dosage must be increased in proportion to increased swath to maintain the same level of mosquito control. 8) Dispersal speed within a range of 2.5-20 mph is not a factor affecting efficacy if insecticide rate and optimum droplet size are maintained. 9) The results of caged mosquito assays are comparable with reductions in free-flying natural populations. 10) The field efficacies of mosquito adulticides applied as ULV ground aerosols are predictable from the results of laboratory wind-tunnel tests. 11) Results of field tests in open to moderately open terrain during favorable meteorological conditions indicated that ULV insecticidal aerosol application rates producing 90% or more control of Anopheles, Culex, and Psorophora spp. are below or approximately equal to maximum United States Environmental Protection Agency label rates. Against some Aedes spp., some pyrethroid insecticides must be synergized to produce 90% control at label rates. 12) Results of field tests in residential areas with moderate to dense vegetation and in citrus groves or other densely wooded areas showed that insecticide rates of ULV ground aerosols must be increased 2-3-fold to obtain 90% or more control of adult mosquitoes. However, the maximum rates on some insecticide labels would have to be increased to allow higher application rates. 13) Applications of ULV ground aerosols of insecticide in accordance with label directions following sunset do not pose a serious threat to humans, nontarget beneficial animals, or automotive paints. 14) Some aerosol generators operated at high RPM levels exceed the OSHA 8-h hearing hazard criteria of 90 dBA and may require hearing protectors for operators. PMID:9813829

  12. Genetics as a component of vector mosquito control in East Africa

    International Nuclear Information System (INIS)

    Among the proposed genetic control methods that have been tested with a degree of success are the release of sterile males, cytoplasmically incompatible strains and strains carrying chromosomal aberrations. In East Africa, the most important mosquitoes are Anopheles gambiae sensu strictu, which transmits malaria, filariasis and the O'nyong-nyong virus; An. arabiensis, which transmits malaria, filariasis and the Tatguine virus; and An. funestus, which transmits malaria, filariasis and the O'nyong-nyong and Tanga viruses. Other important vectors are Aedes simpsoni, which transmits yellow fever, and Ae. africanus, which is responsible for the forest cycle of the disease among monkeys. Cytological examination of specimens of An. gambiae sensu lato resulted in 804 positive identifications of the XB type chromosome only, indicating that An. arabiensis is the most abundant, and probably the only, member of the complex present, and constitutes close to 65.7% of the total mosquito population. Blood meal analysis of 1024 specimens showed its marked preference for bovid (51.9%) and human (28.1%) blood. Sporozoite rating by dissection and enzyme linked immunosorbent assay averaged 0.02%. Control methods tried in the past include chemical spraying and environmental management in the Kisumu area. A trial against An. arabiensis is suggested at Karima village, in Mwea, whereby an integrated approach incorporating environmental, chemical and genetic measures could be undertaken. This enetic measures could be undertaken. This would take advantage of the low population during the dry season from mid-December to mid-April and would involve biological larviciding, mass pyrethrum spraying and the release of sterile males. There is a lack of adequate genetic knowledge of this species, especially genetic markers and linkage relationships, even though chromosome maps are available and inversion polymorphism is better understood. Notice should be taken of the reportedly discouraging results of genetic control trials, where failure has been attributed to immigration, poor competitiveness of laboratory produced males, failure to mate or density dependent mortality. (author). 56 refs, 2 tabs

  13. Impact of Educational Intervention Regarding Mosquito Borne Diseases and Their Control Measures among The Link Workers of Urban Health Centers (UHCs of Ahmedabad City

    Directory of Open Access Journals (Sweden)

    Fancy Manish

    2012-01-01

    Full Text Available Background: In urban area link workers are playing key role in implementing anti-larval measures and behaviour change communication at community level to prevent and control mosquito borne diseases. Objectives: To check baseline knowledge of link workers regarding mosquito borne diseases and control measures and assess their knowledge 14 days after single educational interventional training. Methodology: All 274 link workers of 17 selected UHCs out of total 57 UHCs were taken as study population and their baseline knowledge regarding mosquito borne diseases and mosquito control measures was assessed by questionnaire. Single educational training for 45 minutes was given to groups of link workers and their post– intervention knowledge for same was assessed after 14 days. Mean, Wilcoxon sign-rank test were applied. Results: Mean age of link workers was 31.3 + 4.8 years. The knowledge regarding Chikungunya, Dengue and Malaria was mosquito borne diseases was respectively 55.5%, 87.9% and 95.5% which was increase after intervention to 100%. But 14.4% did not know filariasis is mosquito borne disease even after training. All link workers know about the chemical (Temephos used for mosquito control (100% but knowledge of proper temephos dose for different volume of water containers was significantly improved after intervention. The overall knowledge regarding mosquito & mosquito control measures was significantly improved after intervention (p value <0.05. Conclusion: Even though link workers were involved in anti-larval activities since from many years, many link workers had poor knowledge regarding the mosquito borne diseases and control measures.

  14. Guidelines to site selection for population surveillance and mosquito control trials: a case study from Mauritius.

    Science.gov (United States)

    Iyaloo, Diana P; Elahee, Khouaildi B; Bheecarry, Ambicadutt; Lees, Rosemary Susan

    2014-04-01

    Many novel approaches to controlling mosquito vectors through the release of sterile and mass reared males are being developed in the face of increasing insecticide resistance and other limitations of current methods. Before full scale release programmes can be undertaken there is a need for surveillance of the target population, and investigation of parameters such as dispersal and longevity of released, as compared to wild males through mark-release-recapture (MRR) and other experiments, before small scale pilot trials can be conducted. The nature of the sites used for this field work is crucial to ensure that a trial can feasibly collect sufficient and relevant information, given the available resources and practical limitations, and having secured the correct regulatory, community and ethical approvals and support. Mauritius is considering the inclusion of the sterile insect technique (SIT), for population reduction of Aedes albopictus, as a component of the Ministry of Health and Quality of Life's 'Operational Plan for Prevention and Control of Chikungunya and Dengue'. As part of an investigation into the feasibility of integrating the SIT into the Integrated Vector Management (IVM) scheme in Mauritius a pilot trial is planned. Two potential sites have been selected for this purpose, Pointe des Lascars and Panchvati, villages in the North East of the country, and population surveillance has commenced. This case study will here be used to explore the considerations which go into determining the most appropriate sites for mosquito field research. Although each situation is unique, and an ideal site may not be available, this discussion aims to help researchers to consider and balance the important factors and select field sites that will meet their needs. PMID:24280144

  15. A global assembly of adult female mosquito mark-release-recapture data to inform the control of mosquito-borne pathogens

    OpenAIRE

    Guerra, C.A.; Reiner Jr, R.C.; Perkins, T.A.; Lindsay, S.W.; Midega, J.T.; Brady, O.J.; Barker, C.M.; Reisen, W. K.; Harrington, L.C.; Takken, W.; Kitron, U.; Lloyd, A.L.; Hay, S I; Scott, T.W.; Smith, D. L.

    2014-01-01

    Background Pathogen transmission by mosquitos is known to be highly sensitive to mosquito bionomic parameters. Mosquito mark-release-recapture (MMRR) experiments are a standard method for estimating such parameters including dispersal, population size and density, survival, blood feeding frequency and blood meal host preferences. Methods We assembled a comprehensive database describing adult female MMRR experiments. Bibliographic searches were used to build a digital library of MMRR studies a...

  16. Chlorfenapyr: a pyrrole insecticide for the control of pyrethroid or DDT resistant Anopheles gambiae (Diptera: Culicidae) mosquitoes.

    Science.gov (United States)

    N'Guessan, R; Boko, P; Odjo, A; Akogbéto, M; Yates, A; Rowland, M

    2007-04-01

    Owing to the development and spread of pyrethroid resistance in Anopheles gambiae in Africa there is an urgent need to develop alternative insecticides to supplement the pyrethroids. Chlorfenapyr is a pyrrole insecticide first commercialized for the control of agricultural pests and termites. Performance against An. gambiae bearing kdr (pyrethroid and DDT resistance) or Ace-1(R) insensitive acetylcholinesterase (organophosphate and carbamate resistance) mechanisms was studied using a variety of adult bioassay tests including a simulated-experimental hut system (tunnel tests) that allows uninhibited mosquito behaviour/insecticide interactions. Strains resistant to pyrethroids and organophosphates showed no cross resistance to chlorfenapyr. In cone bioassays on treated netting the mortality of adult mosquitoes showed an unexpected curvilinear response, with highest mortality occurring at intermediate dosages. Adults expressed irritability to chlorfenapyr at higher dosages, which might explain the dosage-mortality trend. Toxic activity of chlorfenapyr was slow compared to conventional neurotoxic insecticides and additional mortality occurred between 24h and 72 h. In tunnel tests, the dosage-mortality trend showed a more typical sigmoid response and most mortality occurred during the first 24h. Mosquito penetration through the holed, treated netting showed only limited inhibition and blood-feeding was not inhibited. Mortality rates in the kdr strain exposed to chlorfenapyr treated netting in tunnel tests were much higher than with permethrin treated netting over the same 100-500 mg/m(2) dosage range. Chlorfenapyr has potential for malaria control in treated-net or residual spraying applications in areas where mosquitoes are pyrethroid resistant. For treated-net applications chlorfenapyr might be combined with pyrethroid as a mixture to provide personal protection as well as to give control of resistant mosquitoes. PMID:17466253

  17. Toxicological effects of prolonged and intense use of mosquito coil emission in rats and its implications on malaria control.

    Science.gov (United States)

    Idowu, Emmanuel Taiwo; Aimufua, Oyenmwen Judith; Ejovwoke, Yomi-Onilude; Akinsanya, Bamidele; Otubanjo, Olubumi Adetoro

    2013-09-01

    Mosquito coil is a vector control option used to prevent malaria in low income counties, while some studies have addressed this issue, additional reseach is required to increase knowledge on the adverse health effects caused by the prolonged use of coils. In this study we investigated the toxicological effects of fumes from two locally manufactured mosquito coil insecticides (with pyrethroids: transfluthrin and d-allethrin as active ingredients) on male albino rats. For this, we recorded the haematological and biochemical indices, and made histopathology and mutagenicity evaluations in rats exposed to mosquito fumes during 2, 4, 8, 12 and 16 week periods. Haematological determination was performed using automated hematology analyzer to determine White Blood Cell (WBC), Packed Cell Volume (PCV), Red Blood Cell (RBC) and Platelet (PLT) counts, while biochemical evaluations were determined using available commercial kits. Gross histopathological changes were studied for the kidney, liver and lungs in sacrificed rats. The rat sperm head abnormalities assessment was used to evaluate mutagenicity. Mosquito coil fumes produced significant increase (P 0.05). Mutagenicity assessment revealed sperm abnormality was statistically significant (P < 0.05) compared with the control at 8, 12 and 16 weeks post exposure to transfluthrin. Histological studies revealed severe lung damage evidenced by interstitial accumulations, pulmonary oedema and emphysema in exposed rats. Intracellular accumulations and severe sinusoidal congestion of liver cells were observed from 12 weeks exposure, indicating liver damage. Our studies indicate that mosquito coil fumes do initiate gradual damage to the host. These pathological effects must be taken into consideration by the malaria control program, particularly when regulating their long term and indoor usage. PMID:24027936

  18. 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

    Directory of Open Access Journals (Sweden)

    Adrias Araceli Q

    2010-05-01

    Full Text Available Abstract 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.

  19. Influence of density on intraguild predation of aquatic Hemiptera (Heteroptera: implications in biological control of mosquito

    Directory of Open Access Journals (Sweden)

    S. Brahma

    2014-04-01

    Full Text Available The water bugs Diplonychus rusticus (Fabricius (Heteroptera: Belostomatidae and Anisops bouvieri (Kirkaldy (Heteroptera: Notonectidae co-occur in wetlands sharing mosquito larvae as prey. As a consequence, an asymmetrical intraguild predation (IGP involving D. rusticus as IG predator and A. bouvieri as IG prey can be possible, the outcome of which may vary with the relative density of interacting species. Based on this proposition density dependent effects on the IG prey and shared prey mortality were assessed in the laboratory using varying numbers of IG predator and shared prey (IV instar Culex quinquefasciatus larva. In contrast to single predator system, mosquito larvae were proportionately less vulnerable to predation in IGP, at low density of shared prey. An increase in density of mosquito decreased the mortality of IG prey (A. bouvieri, but the mean mortality of the IG prey increased with the density of IG predator, in IGP system. Increase in density of mosquito and D. rusticus enhanced risk to predation of mosquito while reducing the mortality of A. bouvieri. Interaction between D. rusticus and A. bouvieri as a part of IGP system provides a possible reason of coexistence of mosquito immature along with predators in wetlands. Biological regulation of mosquitoes may be affected, if appropriate predator numbers are not available in the habitats.

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

    Science.gov (United States)

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

    2007-04-01

    Five aromatic plants, Carum carvi (caraway), Apium graveolens (celery), Foeniculum vulgare (fennel), Zanthoxylum limonella (mullilam) and Curcuma zedoaria (zedoary) were selected for investigating larvicidal potential against mosquito vectors. Two laboratory-reared mosquito species, Anopheles dirus, the major malaria vector in Thailand, and Aedes aegypti, the main vector of dengue and dengue hemorrhagic fever in urban areas, were used. All of the volatile oils exerted significant larvicidal activity against the two mosquito species after 24-h exposure. Essential oil from mullilam was the most effective against the larvae of A. aegypti, while A. dirus larvae showed the highest susceptibility to zedoary oil. PMID:17337133

  1. Perspectives in the control of infectious diseases by transgenic mosquitoes in the post-genomic era: a review

    Directory of Open Access Journals (Sweden)

    Márcia Aparecida Sperança

    2007-06-01

    Full Text Available Arthropod-borne diseases caused by a variety of microorganisms such as dengue virus and malaria parasites afflict billions of people worldwide imposing major economic and social burdens. Despite many efforts, vaccines against diseases transmitted by mosquitoes, with the exception of yellow fever, are not available. Control of such infectious pathogens is mainly performed by vector management and treatment of affected individuals with drugs. However, the numbers of insecticide-resistant insects and drug-resistant parasites are increasing. Therefore, inspired in recent years by a lot of new data produced by genomics and post-genomics research, several scientific groups have been working on different strategies to control infectious arthropod-borne diseases. This review focuses on recent advances and perspectives towards construction of transgenic mosquitoes refractory to malaria parasites and dengue virus transmission.

  2. Perspectives in the control of infectious diseases by transgenic mosquitoes in the post-genomic era: a review

    Scientific Electronic Library Online (English)

    Márcia Aparecida, Sperança; Margareth Lara, Capurro.

    2007-06-01

    Full Text Available Arthropod-borne diseases caused by a variety of microorganisms such as dengue virus and malaria parasites afflict billions of people worldwide imposing major economic and social burdens. Despite many efforts, vaccines against diseases transmitted by mosquitoes, with the exception of yellow fever, ar [...] e not available. Control of such infectious pathogens is mainly performed by vector management and treatment of affected individuals with drugs. However, the numbers of insecticide-resistant insects and drug-resistant parasites are increasing. Therefore, inspired in recent years by a lot of new data produced by genomics and post-genomics research, several scientific groups have been working on different strategies to control infectious arthropod-borne diseases. This review focuses on recent advances and perspectives towards construction of transgenic mosquitoes refractory to malaria parasites and dengue virus transmission.

  3. Assessing key safety concerns of a Wolbachia-based strategy to control dengue transmission by Aedes mosquitoes

    Scientific Electronic Library Online (English)

    Jean, Popovici; Luciano A, Moreira; Anne, Poinsignon; Inaki, Iturbe-Ormaetxe; Darlene, McNaughton; Scott L, O' Neill.

    2010-12-01

    Full Text Available Mosquito-borne diseases such as dengue fever, chikungunya or malaria affect millions of people each year and control solutions are urgently needed. An international research program is currently being developed that relies on the introduction of the bacterial endosymbiont Wolbachia pipientis into Ae [...] des aegypti to control dengue transmission. In order to prepare for open-field testing releases of Wolbachia-infected mosquitoes, an intensive social research and community engagement program was undertaken in Cairns, Northern Australia. The most common concern expressed by the diverse range of community members and stakeholders surveyed was the necessity of assuring the safety of the proposed approach for humans, animals and the environment. To address these concerns a series of safety experiments were undertaken. We report in this paper on the experimental data obtained, discuss the limitations of experimental risk assessment and focus on the necessity of including community concerns in scientific research.

  4. Assessing key safety concerns of a Wolbachia-based strategy to control dengue transmission by Aedes mosquitoes

    Directory of Open Access Journals (Sweden)

    Jean Popovici

    2010-12-01

    Full Text Available Mosquito-borne diseases such as dengue fever, chikungunya or malaria affect millions of people each year and control solutions are urgently needed. An international research program is currently being developed that relies on the introduction of the bacterial endosymbiont Wolbachia pipientis into Aedes aegypti to control dengue transmission. In order to prepare for open-field testing releases of Wolbachia-infected mosquitoes, an intensive social research and community engagement program was undertaken in Cairns, Northern Australia. The most common concern expressed by the diverse range of community members and stakeholders surveyed was the necessity of assuring the safety of the proposed approach for humans, animals and the environment. To address these concerns a series of safety experiments were undertaken. We report in this paper on the experimental data obtained, discuss the limitations of experimental risk assessment and focus on the necessity of including community concerns in scientific research.

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

    Science.gov (United States)

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

    2014-01-01

    Introduction The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Temephos is an organophosphate insecticide used globally to suppress Ae. aegypti larval populations but resistance has evolved in many locations. Methodology/Principal Findings Quantitative Trait Loci (QTL) controlling temephos survival in Ae. aegypti larvae were mapped in a pair of F3 advanced intercross lines arising from temephos resistant parents from Solidaridad, México and temephos susceptible parents from Iquitos, Peru. Two sets of 200 F3 larvae were exposed to a discriminating dose of temephos and then dead larvae were collected and preserved for DNA isolation every two hours up to 16 hours. Larvae surviving longer than 16 hours were considered resistant. For QTL mapping, single nucleotide polymorphisms (SNPs) were identified at 23 single copy genes and 26 microsatellite loci of known physical positions in the Ae. aegypti genome. In both reciprocal crosses, Multiple Interval Mapping identified eleven QTL associated with time until death. In the Solidaridad×Iquitos (SLD×Iq) cross twelve were associated with survival but in the reciprocal IqxSLD cross, only six QTL were survival associated. Polymorphisms at acetylcholine esterase (AchE) loci 1 and 2 were not associated with either resistance phenotype suggesting that target site insensitivity is not an organophosphate resistance mechanism in this region of México. Conclusions/Significance Temephos resistance is under the control of many metabolic genes of small effect and dispersed throughout the Ae. aegypti genome. PMID:25330200

  6. Water management as a tool for malaria mosquito control? The case of the Office du Niger, Mali

    OpenAIRE

    Klinkenberg, E.; Huibers, F. P.; Takken, W.; Toure, Y. T.

    2002-01-01

    A field study was carried out in the rice irrigation scheme Office du Niger, Mali, to observe malaria mosquito larval development as related to differences in field irrigation practices, such as water level, irrigation application and irrigation frequency. The main aim was to find out to what extent field water management can be considered as a tool for vector control for this irrigation system. The results show that minor differences in water management do result in small differences in mosq...

  7. Why do we need alternative tools to control mosquito-borne diseases in Latin America?

    Directory of Open Access Journals (Sweden)

    Rafael Maciel-de-Freitas

    2012-09-01

    Full Text Available In this opinion paper, we discuss the potential and challenges of using the symbiont Wolbachia to block mosquito transmitted diseases such as dengue, malaria and chikungunya in Latin America.

  8. Why do we need alternative tools to control mosquito-borne diseases in Latin America?

    Scientific Electronic Library Online (English)

    Rafael, Maciel-de-Freitas; Raquel, Aguiar; Rafaela V, Bruno; Maria Cristina, Guimarães; Ricardo, Lourenço-de-Oliveira; Marcos HF, Sorgine; Cláudio J, Struchiner; Denise, Valle; Scott L, O' Neill; Luciano A, Moreira.

    2012-09-01

    Full Text Available In this opinion paper, we discuss the potential and challenges of using the symbiont Wolbachia to block mosquito transmitted diseases such as dengue, malaria and chikungunya in Latin America. [...

  9. O aproveitamento do resíduo da indústria do sisal no controle de larvas de mosquitos

    Directory of Open Access Journals (Sweden)

    Pizarro Ana Paula B.

    1999-01-01

    Full Text Available Descreve-se o aproveitamento do resíduo do desfibramento das folhas de Agave sisalana, como um larvicida para o combate a mosquitos transmissores de doenças tropicais. Durante 24 horas, larvas de Aedes aegypti e Culex quinquefasciatus foram expostas a concentrações diferentes do extrato da planta para determinar as concentrações letais. Para A. aegypti foi constatada a CL50 em 322ppm e para C. quinquefasciatus em 183ppm. Foi investigada a ação de saponinas existentes na planta, ficando evidenciado que o resíduo de A. sisalana é ativo através da interação de vários dos seus componentes. Este extrato poderá ser utilizado em campo, na concentração de 100ppm para C. quinquefasciatus com um aumento do tempo de exposição para três dias, obtendo-se uma mortalidade de 100% das larvas. Este produto, porém, não é recomendado para o controle de A. aegypti, devido à necessidade de uma alta concentração para a obtenção de 100% de mortalidade das larvas e ao fato destas se desenvolverem preferencialmente em água potável.

  10. Risk assessment for adult butterflies exposed to the mosquito control pesticide naled

    Science.gov (United States)

    Bargar, Timothy A.

    2012-01-01

    A prospective risk assessment was conducted for adult butterflies potentially exposed to the mosquito control insecticide naled. Published acute mortality data, exposure data collected during field studies, and morphometric data (total surface area and fresh body weight) for adult butterflies were combined in a probabilistic estimate of the likelihood that adult butterfly exposure to naled following aerial applications would exceed levels associated with acute mortality. Adult butterfly exposure was estimated based on the product of (1) naled residues on samplers and (2) an exposure metric that normalized total surface area for adult butterflies to their fresh weight. The likelihood that the 10th percentile refined effect estimate for adult butterflies exposed to naled would be exceeded following aerial naled applications was 67 to 80%. The greatest risk would be for butterflies in the family Lycaenidae, and the lowest risk would be for those in the family Hesperidae, assuming equivalent sensitivity to naled. A range of potential guideline naled deposition levels is presented that, if not exceeded, would reduce the risk of adult butterfly mortality. The results for this risk assessment were compared with other risk estimates for butterflies, and the implications for adult butterflies in areas targeted by aerial naled applications are discussed.

  11. Life-table analysis of Anopheles malaria vectors: generational mortality as tool in mosquito vector abundance and control studies

    Directory of Open Access Journals (Sweden)

    Godwin Ray Anugboba Okogun

    2005-06-01

    Full Text Available Background & objectives: Vector control will for sometime remain a primary weapon in the waragainst vector borne diseases. Malaria is of paramount importance in this with its associated highmorbidity and mortality especially in sub-Saharan Africa. This study on generational mortality associatedfactors in Anopheles mosquitoes life-table analysis was designed to investigate the fecundity,levels of mortality and mortality associated factors at the aquatic stages of anopheline malaria vectors.Methods: Mortality associated factors were investigated at the eggs, I and II instar larval, III and IVinstar larval and pupal stages of two anopheline species— Anopheles pseudopunctipennis (Theobaldand An. gambiae life-cycles in screen cages. Adult male and female mosquitoes were membrane filterfedand algae in culture medium formed the bulk of food substances for the larval stage. Environmentaltemperature of culture media, pH and some associated physio-chemical factors were also determined.Results: Results showed significant mortality rates at various aquatic stages. Infertility, cannibalismand environmental factors were the major factors responsible for mortality at the egg, larval and pupalstages respectively.Interpretation & conclusion: The aquatic stages of Anopheles mosquito mortality factor K and themortality factors at the various stages investigated k1, k2, k3 and k4 are discussed. Our recommendationsinclude further studies on the possible genetic modification of predacious An. pseudopunctipennislarvae and/or its modification for the production of sterile/infertile eggs as possible alternativesin the reduction and control of anopheline malaria burden.

  12. Scepticism towards insecticide treated mosquito nets for malaria control in a rural community in northwestern Tanzania

    DEFF Research Database (Denmark)

    Nnko, Soori; Whyte, Susan Reynolds

    2012-01-01

    Despite existence of effective tools for malaria control, malaria continues to be one of the leading killer diseases especially among under-five year children and pregnant women in poor rural populations of Sub Saharan Africa. In Tanzania Mainland the disease contributes to 39.4% of the total OPD attendances. In terms of mortality, malaria is known to be responsible for more than one third of deaths among children of age below 5 years and also contributes for up to one fifth of deaths among pregnant women. This paper is based on a study conducted in a rural community along the shores of Lake Victoria in Mwanza region, North-Western Tanzania. The study explores reasons for scepticism and low uptake of insecticide treated mosquito nets (ITNs) that were promoted through social marketing strategy for malaria control prior to the introduction of long lasting nets (LLN). The paper breaks from traditional approach that tend to study low uptake of health interventions in terms of structural practical constraints – cost, accessibility, everyday priorities – or in terms of cognition – insufficient knowledge of benefits e.g. ignorance of public health messages. This paper has shown that, the majority of people who could afford the prices of ITNs and who knew where to obtain the insecticides did not necessarily buy them. This suggests that, although people tend to report costrelated factors as a barrier against the use of ITNs, there are other critical concerns at work. Without underestimating the practical factors, our study have recommended to consider critical examinations of those other concerns that hinder optimal utilization of ITN for malaria control, and the basis for those concerns.

  13. Methods for Control of Vector Mosquitoes and the Possible Role of SIT

    International Nuclear Information System (INIS)

    a) China, Vietnam and Singapore. Approximately 10 million bednets are treated with insecticide in China and Vietnam annually. The nets are privately owned but treatment is provided by health authorities who also carry out house spraying in the same areas. Artesunate (from Artemesia) was shown to be effective against P. falciparun but it is resistant to other drugs; however, the combined use of artesunate and treated bednets has greatly reduced malaria burden in Vietnam in the last 10 years. Despite a sophisticated Aedes control programme, Singapore remains endemic for dengue. The use of SIT for routine control or to eradicate Ae. aegypti and Ae. albipictus from the island and nearby parts of Malaysia has been suggested. b) Indian sub-continent. Though the number of malaria cases is less than what it used to be in the 1930s, it rose in the 1960s at the height of house spraying campaigns when India used 18,000 tonnes of DDT annually. Sri Lanka switched from DDT in 1970s and India has stated that it intends to do so. Rural malaria is mainly transmitted by An. culicifacies and other species whilst urban malaria is transmitted by An. stephensi. If An. stephensi exists as 'urban islands' it should be possible to control or eradicate by SIT; however, this needs to be confirmed. In the 1970s SIT trials with Culex and Aedes showed that moderately competitive sterile males could be produced but village to village movement of Culex pointed to the fact that urban populations couled to the fact that urban populations could be better targets. Sex separation in culicine mosquitoes can be done on the basis of pupal size. c) An. arabiensis in north east Africa and Red Sea coast. It is the only man-biting member of the An. gambiae complex in central and northern Sudan, Ethiopia and the Arabian Red Sea coast. An. arabiensis invaded Upper Egypt in 1942 and caused a malaria epidemic as it is a much more efficient vector than A. pharoensis but it was eradicated using arsenical larvicide (and some DDT) by 1945. The creation of Lake Nasser by Aswan High Dam has not (yet) led to another invasion by An. arabiensis into Egypt. There were successful house spraying programmes in the Gezira from the 1960s to 90s with switching of insecticides as resistances developed. There have been several research studies on the survival of An. arabiensis and malaria through the long dry season of eastern Sudan but the picture is far from clear. Filiriasis transmitted by Cx. pipiens is a more important mosquito borne disease than malaria in Egypt at present. d) Europe and Central Asia. Malaria disappeared from northern Europe in the first half of the 250th century. It was eradicated from southern Europe and USSR between 1940s and 60s but there has been a resurgence of major epidemics in Central Asia in the 1990s. The An. maculipennis complex is only susceptible to P. vivax, buat other species are susceptible to P. falciparum. There are thousands of imported cases of malaria into Europe each year and global warming would increase the chances of any Plasmodium gametocytes ingested by a mosquito competing their development. The prompt treatment of imported malaria cases renders infection of mosquitoes by gametocytes very improbable. Invading populations of Aedes albopictus in Italy and Albania are potential dengue vectors and have been considered as targets for eradication by SIT. e) Tropical Africa. The An. gambiae complex and An. funestus are highly anthropophilic and are therefore efficient vectors. About 80% of the world's annual 400 million clinical malaria cases are in this region as well as about 90% of worlds annual 1-2.5 million malaria deaths. The death rate is rising probably because of rising drug resistance. f) Southern Africa. DDT spraying has greatly reduced malaria burden compared to the 1930's. There was no DDT resistance and An. funestus was eradicated in South Africa and Madagascar highlands. The switch to pyrethroids in S. Africa in 1996 was followed by 4 fold increase in malaria and the re-appearance of An. funestus which was resistant to pyrethr

  14. The Potential for Genetic Control of Malaria-Transmitting Mosquitoes. Report of a Consultants Group Meeting. Working Material

    International Nuclear Information System (INIS)

    Since the beginning of the Joint FAO/IAEA Division Programme on the research and development of insect pest control methodology, emphasis has been placed on the basic and applied aspects of implementing the Sterile Insect Technique (SIT). Special emphasis has always been directed at the assembly of technological progress into workable systems that can be implemented in developing countries. The general intention is to solve problems associated with insect pests that have an adverse impact on public health and the production of food and fibre. For certain insects, SIT has proven to be a powerful method for control, but for a variety of reasons this technology has not been tried on an operational scale for most of the pest species of insects that exact a toll on the endeavors of humans. The Joint FAO/IAEA Division convened a Consultants Group Meeting to examine 'The Potential for Genetic Control of Malaria-Transmitting Mosquitoes', with emphasis to be placed on the SIT. A group of five scientists met, 26-30 April 1993, to examine the current status and the future potential of genetic control for malaria mosquitoes. In most of the tropical, developing countries, and to some extent in temperate regions of the world, Anopheles mosquitoes cause havoc by transmitting malaria, a dreaded disease that causes high mortality amongst children and diminishes productivity of adults. The importance of malaria as a deterrent to further economic growth in a large part of the world cannot be over-emphasized. Malaria is a severe problem because there are inadequacies in the technology available for control. As a result of the deliberations at the meeting, the consultants prepared a list of recommendations concerning the consensus opinions about the development of genetic control for malaria vector control. This report presents the findings and recommendations of the Consultants Group Meeting.

  15. Wolbachia-based population control strategy targeting Culex quinquefasciatus mosquitoes proves efficient under semi-field conditions.

    Science.gov (United States)

    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

  16. Advantages of larval control for African malaria vectors: Low mobility and behavioural responsiveness of immature mosquito stages allow high effective coverage

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2002-06-01

    Full Text Available Abstract Background Based on sensitivity analysis of the MacDonald-Ross model, it has long been argued that the best way to reduce malaria transmission is to target adult female mosquitoes with insecticides that can reduce the longevity and human-feeding frequency of vectors. However, these analyses have ignored a fundamental biological difference between mosquito adults and the immature stages that precede them: adults are highly mobile flying insects that can readily detect and avoid many intervention measures whereas mosquito eggs, larvae and pupae are confined within relatively small aquatic habitats and cannot readily escape control measures. Presentation of the hypothesis We hypothesize that the control of adult but not immature mosquitoes is compromised by their ability to avoid interventions such as excito-repellant insecticides. Testing the hypothesis We apply a simple model of intervention avoidance by mosquitoes and demonstrate that this can substantially reduce effective coverage, in terms of the proportion of the vector population that is covered, and overall impact on malaria transmission. We review historical evidence that larval control of African malaria vectors can be effective and conclude that the only limitations to the effective coverage of larval control are practical rather than fundamental. Implications of the hypothesis Larval control strategies against the vectors of malaria in sub-Saharan Africa could be highly effective, complementary to adult control interventions, and should be prioritized for further development, evaluation and implementation as an integral part of Rolling Back Malaria.

  17. Alternative methodologies in the integrated control of urban mosquito larvae: water surface obliteration techniques Metodologías alternativas en el control integrado de larvas de mosquitos urbanos: técnicas de obliteración de lámina de agua Metodologias alternativas no controlo integrado de larvas de mosquitos nas áreas urbanas: técnicas de obliteração da superfície da água

    Directory of Open Access Journals (Sweden)

    Roger Eritja

    2012-12-01

    Full Text Available The public health risk associated to mosquitoes has increased in Spain by the introduction of the Asian Tiger Mosquito (Aedes albopictus which is a well-known disease vector. Integrated control methodologies basically rely on larviciding by weekly applications of microbial biocides that have no residual effect. In some special cases, such as swimming pools in abandoned estates, this weekly schedule cannot be achieved due to difficulties of access and operational reasons. In these circumstances, there are no appropriate biocidal options except for Insect Growth Regulators (IGR, which do not provide more than a few weeks of residual efficiency. We present here the practical application of a well-known technique for controlling mosquito larvae in urban environments by altering the water/air interface. The adding to the water surface of a thick layer of beads made from inert, floating materials is described. The layer of beads impedes oviposition and adversely affects the breathing of the larvae. This technique avoids the regular application of chemical pesticides, as well as providing improved sustainability and higher efficiency times. Caution notes and side effects are also discussed.Los mosquitos son un riesgo relevante para la salud pública que se ha visto incrementado con la llegada de Aedes albopictus, el mosquito tigre, potencial transmisor de varias enfermedades. El método de elección para su control es la eliminación de las larvas acuáticas mediante biocidas de origen biológico, que se realiza semanalmente debido a su nula persistencia. En determinados puntos donde esta periodicidad no puede mantenerse, como piscinas en fincas abandonadas, no existen opciones biocidas adecuadas más residuales exceptuando los inhibidores del crecimiento, que sin embargo no suelen proporcionar una residualidad superior a unas pocas semanas (de dos a cuatro. Se presenta la aplicación práctica de una técnica de control de larvas de mosquito en medios urbanos consistente en alterar la interfase agua/aire. Se describe la aplicación de materiales granulados inertes flotantes sobre las superficies para impedir la puesta de huevos y la respiración de las larvas, con el consiguiente beneficio de evitar la aplicación periódica de plaguicidas químicos, así como una sostenibilidad y perduración muy superiores. Se discuten asimismo los riesgos propios de estas estrategias.Os mosquitos são um risco significativo para a saúde pública, que aumentou com a chegada do Aedes albopictus, mosquito tigre, potencial transmissor de várias doenças. O método de escolha para o seu controle é a eliminação das larvas aquáticas com produtos biocidas de origem biológica, realizada semanalmente devido a sua persistência nula. Em determinados pontos onde essa recorrência não pode ser mantida, como piscinas em fazendas abandonadas, não há suficientes opções residuais biocidas com excepção dos inibidores de crescimento, mas não costumam fornecer um residual maior do que duas a quatro semanas. Apresenta-se a aplicação prática de uma técnica de controle de larvas do mosquito em ambientes urbanos consistendo em alterar a interface água/ar. Descreve-se a aplicação de materiais granulados inertes flutuando na superfície para evitar a postura de ovos e respiração das larvas, com o consequente benefício de evitar a aplicação periódica de pesticidas químicos, com uma melhor sustentabilidade e duração. Discutimos também os riscos inerentes a estas estratégias.

  18. First Planning Meeting on Development of the Sterile Insect Techniques for Control of Malaria-Transmitting Mosquitoes

    International Nuclear Information System (INIS)

    At the request of Member States a series of consultant's reports were commisioned over the past 10 years to assess the potential of developing and using the Sterile Insect Technique (SIT) for the control of vectors of malaria. The experts reports recommended that the Agency proceed with such an evaluation. The rationale for the possible inclusion of SIT into malaria vector control were detailed in these reports. All the reports emphasized that significant R and D would be required to develop and evaluate the SIT technology for mosquitoes before operational pilot projects could be initiated. Following the last of these meetings a document was prepared in which the essential R and D components were identified. This plan also included the collection of baseline data from a potential field site in Africa and the proposal that the target species should be Anopheles arabiensis. On the basis of these activities a Technical Co-operation (TC) project was developed which focused on the identification of a potential field site and provided funds for initiation of the collection of epidemiological and entomological data from the site. The R and D requirements for mosquito SIT were addressed in two ways. Firstly by undertaking limited R and D activities at the Agency's Laboratories in Seibersdorf and secondly by elaborating a Co-ordinated Research Project (CRP). The first planning meeting was thus held in Vienna from 5-8 June 2001 with representatives from Ethiopia, Mali, Namibia, Niger, Nigeria, Senegal, South Africa and Sudan; as well as experts from the UK and the USA; and a representative from the World Health Organisation (WHO). The meeting provided a forum for the participants to summarize the current malaria situation, its control and the importance of An. arabiensis in their respective countries. The outside experts complemented these presentations by dealing with specific issues. The objectives of the meeting were to: Review the status of the control of malaria-transmitting mosquitoes in Member States including Government policies; Review the state of art for possible use of SIT for the control of malaria-transmitting mosquitoes; Formulate long-term and short-term strategies and action plans for R and D aimed at possible use of SIT for the control of An. arabiensis; Identify international and regional partners and discuss modalities for co-operation.

  19. Development of Metarhizium anisopliae and Beauveria bassiana formulations for control of malaria mosquito larvae

    Directory of Open Access Journals (Sweden)

    Takken Willem

    2011-02-01

    Full Text Available Abstract Background The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana have demonstrated effectiveness against anopheline larvae in the laboratory. However, utilising these fungi for the control of anopheline larvae under field conditions, relies on development of effective means of application as well as reducing their sensitivity to UV radiation, high temperatures and the inevitable contact with water. This study was conducted to develop formulations that facilitate the application of Metarhizium anisopliae and Beauveria bassiana spores for the control of anopheline larvae, and also improve their persistence under field conditions. Methods Laboratory bioassays were conducted to test the ability of aqueous (0.1% Tween 80, dry (organic and inorganic and oil (mineral and synthetic formulations to facilitate the spread of fungal spores over the water surface and improve the efficacy of formulated spores against anopheline larvae as well as improve spore survival after application. Field bioassays were then carried out to test the efficacy of the most promising formulation under field conditions in western Kenya. Results When formulated in a synthetic oil (ShellSol T, fungal spores of both Metarhizium anisopliae and Beauveria bassiana were easy to mix and apply to the water surface. This formulation was more effective against anopheline larvae than 0.1% Tween 80, dry powders or mineral oil formulations. ShellSol T also improved the persistence of fungal spores after application to the water. Under field conditions in Kenya, the percentage pupation of An. gambiae was significantly reduced by 39 - 50% by the ShellSol T-formulated Metarhizium anisopliae and Beauveria bassiana spores as compared to the effects of the application of unformulated spores. Conclusions ShellSol T is an effective carrier for fungal spores when targeting anopheline larvae under both laboratory and field conditions. Entomopathogenic fungi formulated with a suitable carrier are a promising tool for control of larval populations of malaria mosquitoes. Additional studies are required to identify the best delivery method (where, when and how to make use of the entomopathogenic potential of these fungi against anopheline larvae.

  20. Evaluation of ULV and thermal fog mosquito control applications in temperate and desert environments.

    Science.gov (United States)

    Britch, Seth C; Linthicum, Kenneth J; Wynn, Wayne W; Walker, Todd W; Farooq, Muhammad; Smith, Vincent L; Robinson, Cathy A; Lothrop, Branka B; Snelling, Melissa; Gutierrez, Arturo; Lothrop, Hugh D; Kerce, Jerry D; Becnel, James J; Bernier, Ulrich R; Pridgeon, Julia W

    2010-06-01

    Ultra-low-volume (ULV) and thermal fog aerosol dispersals of pesticides have been used against mosquitoes and other insects for half a century. Although each spray technology has advantages and disadvantages, only 7 studies have been identified that directly compare their performance in the field. US military personnel currently operating in hot-arid environments are impacted by perpetual nuisance and disease vector insect problems, despite adulticide operations using modern pesticide-delivery equipment such as ULV. None of the identified comparative studies has looked at the relative feasibility and efficacy of ULV and thermal fog equipment against mosquitoes in hot-arid environments. In this study we examine the impact of ULV and thermal fog applications of malathion against caged sentinel mosquitoes in the field in a warm temperate area of Florida, followed by a similar test in a hot-dry desert area of southern California. Patterns of mortality throughout 150 m x 150 m grids of sentinel mosquitoes indicate greater efficacy from the thermal fog application in both environments under suboptimal ambient weather conditions. We discuss the implications of these findings for future military preventive medicine activities and encourage further investigations into the relative merits of the 2 technologies for force health protection. PMID:20649128

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

    Science.gov (United States)

    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...

  2. Mosquito control pesticides and sea surface temperatures have differential effects on the survival and oxidative stress response of coral larvae.

    Science.gov (United States)

    Ross, Cliff; Olsen, Kevin; Henry, Michael; Pierce, Richard

    2015-04-01

    The declining health of coral reefs is intensifying worldwide at an alarming rate due to the combined effects of land-based sources of pollution and climate change. Despite the persistent use of mosquito control pesticides in populated coastal areas, studies examining the survival and physiological impacts of early life-history stages of non-targeted marine organisms are limited. In order to better understand the combined effects of mosquito pesticides and rising sea surface temperatures, we exposed larvae from the coral Porites astreoides to selected concentrations of two major mosquito pesticide ingredients, naled and permethrin, and seawater elevated +3.5 °C. Following 18-20 h of exposure, larvae exposed to naled concentrations of 2.96 µg L(-1) or greater had significantly reduced survivorship compared to controls. These effects were not detected in the presence of permethrin or elevated temperature. Furthermore, larval settlement, post-settlement survival and zooxanthellae density were not impacted by any treatment. To evaluate the sub-lethal stress response of larvae, several oxidative stress endpoints were utilized. Biomarker responses to pesticide exposure were variable and contingent upon pesticide type as well as the specific biomarker being employed. In some cases, such as with protein carbonylation and catalase gene expression, the effects of naled exposure and temperature were interactive. In other cases pesticide exposure failed to induce any sub-lethal stress response. Overall, these results demonstrate that P. astreoides larvae have a moderate degree of resistance against short-term exposure to ecologically relevant concentrations of pesticides even in the presence of elevated temperature. In addition, this work highlights the importance of considering the complexity and differential responses encountered when examining the impacts of combined stressors that occur on varying spatial scales. PMID:25527297

  3. Controle de mosquitos com base em larvicidas no Estado do Rio Grande do Sul, Brasil: a escolha do agente de controle

    OpenAIRE

    Ruas-Neto Antônio L.; Silveira Sydnei M.; Colares Evandro Ricardo da C.

    1994-01-01

    Desenvolveu-se neste estudo uma comparação entre larvicidas químicos e biológicos usados em programas de controle de mosquitos no Rio Grande do Sul. Em bioensaios de laboratório contra Culex quinquefasciatus constatou-se que as formulações biológicas líquidas Vectobac 12 AS e Teknar 3000 (Bacillus thuringiensis israelensis), ABG 6262 líquido e em pó (B. sphaericus 2362), foram altamente eficazes. Também as formulações experimentais de B. thuringiensis israelensis produzidas em l...

  4. History of Mosquito Releases for Control and Potential of New Molecular Capabilities

    International Nuclear Information System (INIS)

    Ten different field trials, of varying sizes, have been carried out with sterile mosquitoes, the majority being in the 1970's. The major trials were in India, Burma and El Salvador. The major biological problems encountered were the failure of the sterile males to mate with the wild females and density dependent larval survival. There were also several problems associated with the technology, e.g. failures in mass rearing, inappropriate release technologies and immigration into the treatment area. New transgenic developments may offer some improvements but the above constraints will still need to be solved. Systems to genetically sterilize insects in the field are being evaluated in mosquitoes and have been shown to be successful in Drosophila. The genetic constructs used in Drosophila may well function in Anopheles.

  5. Mosquitoes, models, and dengue.

    Science.gov (United States)

    Lifson, A R

    1996-05-01

    In the last 10 years dengue has spread markedly through Latin America and the Caribbean (Dominican Republic, Jamaica, Barbados, Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Ecuador, Colombia, Venezuela, and Brazil). The mosquito Aedes aegypti has taken advantage of increased urbanization and crowding to transmit the dengue virus. The mosquito infests tires, cans, and water jars near dwellings. The female mosquito practices multiple, interrupted feeding. Thus, mosquito infesting and feeding practices facilitate dengue transmission in crowded conditions. Factors contributing to the spread of dengue include numbers of infected and susceptible human hosts, strain of dengue virus, size of mosquito population, feeding habits, time from infection to ability to transmit virus for both vector and host, likelihood of virus transmission from human to mosquito to human, and temperature (which affects vector distribution, size, feeding habits, and extrinsic incubation period). Public health models may use simulation models to help them plan or evaluate the potential impact of different intervention strategies and/or of environmental changes (e.g., global warming). Other factors contributing to the dengue epidemic are international travel, urbanization, population growth, crowding, poverty, a weakened public health infrastructure, and limited support for sustained disease control programs. Molecular epidemiology by nucleic acid sequence analysis is another sophisticated technique used to study infectious diseases. It showed that dengue type 3 isolated from Panama and Nicaragua in 1994 was identical to that responsible for the major dengue hemorrhagic fever epidemics in Sri Lanka and India in the 1980s. Public health officials must remember three priorities relevant to dengue and other emerging infections: the need to strengthen surveillance efforts, dedicated and sustained involvement in prevention and control needs at the local level, and a strong public health infrastructure at the international, national, and local levels to maintain support for surveillance and control activities. PMID:8622446

  6. Juvenile hormone and its receptor, methoprene-tolerant, control the dynamics of mosquito gene expression

    OpenAIRE

    Zou, Zhen; Saha, Tusar T.; Roy, Sourav; Shin, Sang Woon; Backman, Tyler W. H.; Girke, Thomas; Kevin P. White; Raikhel, Alexander S

    2013-01-01

    Mosquitoes transmit some of the most dangerous human diseases. Microarray analysis of developmental gene dynamics in the female Aedes aegypti fat body has demonstrated that 6,146 genes are differentially expressed during juvenile hormone-dependent posteclosion development. These genes show striking temporal and functional separation. A RNAi microarray screen revealed a differential action of Met in the down- and up-regulation of genes expressed during early and late PE, respectively. Thus, th...

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

    OpenAIRE

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

    2014-01-01

    The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Due to a lack of effective drugs or vaccines, if an epidemic of dengue fever occurs in the near future, the first line of defense will involve the use of insecticides to suppress adult populations of Ae. aegypti. Unfortunately, the species has become resistant to most of the insecticides that can be safely applied. The authors have worked extensively on the mechanisms of resistance to the various insec...

  8. Control of pyrethroid-resistant Anopheles gambiae and Culex quinquefasciatus mosquitoes with chlorfenapyr in Benin

    OpenAIRE

    N Guessan, R.; Boko, P.; Odjo, A.; Knols, B. G. J.; Akogbeto, M.; Rowland, M.

    2009-01-01

    Objective To compare the efficacy of chlorfenapyr applied on mosquito nets and as an indoor residual spray against populations of Anopheles gambiae and Culex quinquefasciatus in an area of Benin that shows problematic levels of pyrethroid resistance. Method Eight-week trial conducted in experimental huts. Results Indoor residual spraying killed 82.9% of An. gambiae overall (mean mortality: 79.5%) compared to 53.5% overall (mean mortality: 61.7%) in the hut containing the lower dosed ITN. Anal...

  9. Attractive toxic sugar baits: control of mosquitoes with the low-risk active ingredient dinotefuran and potential impacts on nontarget organisms in Morocco.

    Science.gov (United States)

    Khallaayoune, Khalid; Qualls, Whitney A; Revay, Edita E; Allan, Sandra A; Arheart, Kristopher L; Kravchenko, Vasiliy D; Xue, Rui-De; Schlein, Yosef; Beier, John C; Müller, Günter C

    2013-10-01

    We evaluated the efficacy of attractive toxic sugar baits (ATSB) in the laboratory and field with the low-risk active ingredient dinotefuran against mosquito populations. Preliminary laboratory assays indicated that dinotefuran in solution with the sugar baits was ingested and resulted in high mortality of female Culex quinquefasciatus Say and Aedes aegypti Linnaeus. Field studies demonstrated >70% reduction of mosquito populations at 3 wk post-ATSB application. Nontarget feeding of seven insect orders-Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, Orthoptera, and Neuroptera-was evaluated in the field after application of attractive sugar baits (ASB) on vegetation by dissecting the guts and searching for food dye with a dissecting microscope. Nontargets were found stained with ASB 0.9% of the time when the application was applied on green nonflowering vegetation. Only two families were significantly impacted by the ASB application: Culicidae (mosquitoes) and Chironomidae (nonbiting midges) of the order Diptera. Pollinators of the other insect orders were not significantly impacted. No mortality was observed in the laboratory studies with predatory nontargets, wolf spiders or ground beetles, after feeding for 3 d on mosquitoes engorged on ATSB applied to vegetation. Overall, this novel control strategy had little impact on nontarget organisms, including pollinators and beneficial insects, and was effective at controlling mosquito populations, further supporting the development of ATSB for commercial use. PMID:24331613

  10. Dopamine Receptor Antagonists as New Mode-of-Action Insecticide Leads for Control of Aedes and Culex Mosquito Vectors

    Science.gov (United States)

    Nuss, Andrew B.; Ejendal, Karin F. K.; Doyle, Trevor B.; Meyer, Jason M.; Lang, Emma G.; Watts, Val J.; Hill, Catherine A.

    2015-01-01

    Background New mode-of-action insecticides are sought to provide continued control of pesticide resistant arthropod vectors of neglected tropical diseases (NTDs). We previously identified antagonists of the AaDOP2 D1-like dopamine receptor (DAR) from the yellow fever mosquito, Aedes aegypti, with toxicity to Ae. aegypti larvae as leads for novel insecticides. To extend DAR-based insecticide discovery, we evaluated the molecular and pharmacological characteristics of an orthologous DAR target, CqDOP2, from Culex quinquefasciatus, the vector of lymphatic filariasis and West Nile virus. Methods/Results CqDOP2 has 94.7% amino acid identity to AaDOP2 and 28.3% identity to the human D1-like DAR, hD1. CqDOP2 and AaDOP2 exhibited similar pharmacological responses to biogenic amines and DAR antagonists in cell-based assays. The antagonists amitriptyline, amperozide, asenapine, chlorpromazine and doxepin were between 35 to 227-fold more selective at inhibiting the response of CqDOP2 and AaDOP2 in comparison to hD1. Antagonists were toxic to both C. quinquefasciatus and Ae. aegypti larvae, with LC50 values ranging from 41 to 208 ?M 72 h post-exposure. Orthologous DOP2 receptors identified from the African malaria mosquito, Anopheles gambiae, the sand fly, Phlebotomus papatasi and the tsetse fly, Glossina morsitans, had high sequence similarity to CqDOP2 and AaDOP2. Conclusions DAR antagonists represent a putative new insecticide class with activity against C. quinquefasciatus and Ae. aegypti, the two most important mosquito vectors of NTDs. There has been limited change in the sequence and pharmacological properties of the DOP2 DARs of these species since divergence of the tribes Culicini and Aedini. We identified antagonists selective for mosquito versus human DARs and observed a correlation between DAR pharmacology and the in vivo larval toxicity of antagonists. These data demonstrate that sequence similarity can be predictive of target potential. On this basis, we propose expanded insecticide discovery around orthologous DOP2 targets from additional dipteran vectors. PMID:25793586

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

    Science.gov (United States)

    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

  12. A five-year integrated mosquito control project in Kavala (N. Greece)

    International Nuclear Information System (INIS)

    Full text: The plain of the Nestos River is a coastal area of 25,000 ha of agricultural land irrigated by the day-regulated waters of the Nestos River. Rice fields (600 individual parcels of 1,900 ha of total surface) represent the most important breeding sites during summer (five larvicide applications on average). Abandoned agricultural land (over 200 fields of 900 ha) receiving occasionally irrigation water constitutes the second most productive mosquito-breeding site (1-2 applications). Approximately 1-2% of the total surface of 6,500 ha of corn cultivation fields is poorly drained and thus about 100 ha produce at least one generation of mosquitoes during the summer. Along its 25 kilometers of seashore, the area of Nestos comprises the lagoons of Kavala (extensive aquaculture), and the last part of the delta of the Nestos River, 11,500 ha of protected wetlands under the Ramsar convention. About 2,000 ha of these wetlands harbours plants such as Arthr. fruticosum, Sal. europea, Ael. littoralis, Ju. maritimus, Sc. maritimus, representing highly productive mosquito breeding sites (1-2 generations during the summer). Ecological mapping involved 3,200 individual vegetation polygons organised in 311 different sampling stations. Larvae sampling protocol was followed on a weekly basis for the individual and/or groups of parcels in the agricultural and natural environment. All the above information was systematically monitored and transferred to an ArcView (8.3)-GIS (Geogrtransferred to an ArcView (8.3)-GIS (Geographical Information System) database for further exploitation. In addition, mosquito breeding sites were recorded in the urban environment: within 9 villages, 2,300 individual residences were monitored and 1,070 cesspools were recorded, out of which more than 50% were producing mosquitoes (1-2 applications). In total 8,500 ha were treated with larvicides by using temephos and diflubenzuron (agricultural land), Bti (natural environment) and MMF-Agnique (urban environment). 70% of the applications were made by air using a spraying helicopter (Hiller) and a specially modified ultra-light motorized (Delta type) equipped with GPS (Geographical Positioning System). During the five years of application of the project, 17 species of mosquitoes have been identified, the most important being Ochlerotatus caspius and Anopheles spp. (human bait and CO2 traps). Nuisance has been considerably reduced since the beginning of the operations, when 1,000 bites/hour were not unusual. Evaluation of the project was made twice through 200 questionnaires in year 2000 and 180 questionnaires in year 2004. Local community is fully supporting the project: 90% of the people are willing to participate financially for the continuation of the project. (author)

  13. Genetic control of insects: Characterization of mobile genetic elements from mosquito genomes

    International Nuclear Information System (INIS)

    The Juan elements constitute a family of LINE's retroposons which are dispersed in the genome of many strains, if not all, of the three mosquito species A. Aegypti, C. pipiens and C. tarsalis. A specific Juan subfamily is amplified and dispersed in the genome of each of these species. They have been designated respectively as Juan A in A. aegypti, Juan C in C. pipiens and Juan Ct in C. tarsalis. The distribution of Juan retroposons among mosquito species does not reflect the phylogeny of these species. Furthermore, the Juan retroposons form homogeneous subfamilies: full-length copies which are reiterated in strains collected from regions covering different continents are nearly identical. These data are interpreted to indicate that the Juan retroposons have spread recently in the mosquito genomes harbouring them, perhaps upon horizontal transfer from other species. Juan A elements have been found in two isolates of A. albopictus and one isolate of A. polynesiensis, whereas numerous other isolates of these two species are devoided of any Juan-like sequence. The unfrequent presence of Juan A elements in some strains of A. albopictus and A. polynesiensis can be the result of an horizontal invasion, but more probably from cross-hybridizations which have been reported sometimes to occur between the former species and A. aegypti. No progeny is obtained when A. albopictus males containing Juan A retroposons are crossed with females lacking these elements, whereas the reciproacking these elements, whereas the reciprocal cross is fertile. Such results suggest that the Juan retroposons may be responsible for incompatibilities between strains. (author). 19 refs, 1 fig., 1 tab

  14. 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

    OpenAIRE

    Scholte, E J

    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 genus Anopheles. Lymphatic filariasis is caused by helminths, the most widespread spec...

  15. The Potential of the Sterile Insect Technique and other Genetic Methods for Control of Malaria-Transmitting Mosquitoes. Report of a Consultants Meeting

    International Nuclear Information System (INIS)

    This report updates information provided by a 1993 consultant group on the use of genetic methods for control of malaria-transmitting mosquitoes. Human malaria parasites of the genus Plasmodium are exclusively transmitted by mosquitoes of the genus Anopheles. Where these two groups co-exist, the transmission of the parasite to humans can create a major health problem. Malaria currently causes 2 million deaths world-wide and approximately 400 million clinical cases annually. There are ca. 15 major vector species and 30-40 vectors of lesser importance. This report considers the practicality of developing the sterile insect technique (SIT) or other genetic mechanisms in order to eradicate mosquito vectors from specific areas. This would interrupt transmission and eliminate malaria in those areas.

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

    Science.gov (United States)

    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

  17. Efficacy of leaves extract of Calotropis procera Ait. (Asclepiadaceae) in controlling Anopheles arabiensis and Culex quinquefasciatus mosquitoes?

    OpenAIRE

    Elimam, Abdalla M.; Elmalik, Khitma H.; Ali, Faysal S.

    2009-01-01

    The present study aimed to investigate, the larvicidal, adult emergence inhibition and oviposition deterrent activity of aqueous leaves extract of Calotropis procera against Anopheles arabiensis and Culex quinquefasciatus as natural mosquito larvicide. The larvicidal activity was monitored against 2nd, 3rd and 4th instar larvae of each mosquito species 24 h post-treatment. Adult emergence inhibition activity was tested by exposing 3rd instar larvae of each mosquito species to different concen...

  18. Genetically Modified Mosquito: Myth and Reality

    Directory of Open Access Journals (Sweden)

    Teh Su Yean

    2013-02-01

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

  19. Oral Delivery of Double-Stranded RNA in Larvae of the Yellow Fever Mosquito, Aedes aegypti: Implications for Pest Mosquito Control

    OpenAIRE

    Singh, Aditi D.; Wong, Sylvia; Ryan, Calen P.; Whyard, Steven

    2013-01-01

    RNA interference has already proven itself to be a highly versatile molecular biology tool for understanding gene function in a limited number of insect species, but its widespread use in other species will be dependent on the development of easier methods of double-stranded RNA (dsRNA) delivery. This study demonstrates that RNA interference can be induced in the mosquito Aedes aegypti L. (Diptera: Culicidae) simply by soaking larvae in a solution of dsRNA for two hours. The mRNA transcripts ...

  20. Modelo de simulación para el control del mosquito Aedes aegypti, transmisor del dengue y la fiebre amarilla, por el crustáceo Mesocyclops spp. A simulation model for the control of the Aedes aegypti, the mosquito vector of dengue and yellow fever, by the crustacean Mesocyclops spp.

    Directory of Open Access Journals (Sweden)

    Jonny E. Duque L.

    2004-04-01

    Full Text Available OBJETIVOS: Se presenta un modelo de simulación que muestra la dinámica de depredación de Mesocyclops spp., sobre Aedes aegypti MÉTODOS: Representado por cuatro ecuaciones diferenciales: H'(t, cantidad de huevos; L'(t, cantidad de larvas; A'(t, cantidad de adultos y C'(t, cantidad de copépodos. Inicialmente las ecuaciones son del tipo clásico presa-depredador, según Lotka y Volterra. Posteriormente se modifica en un sistema con respuesta funcional para invertebrados, según Holling. RESULTADOS: El primer sistema controla y estabiliza la población de mosquitos, el segundo muestra que los copepodos son inefectivos como controladores. CONCLUSIONES: Se reconoce la necesidad de estudiar sistemas presa depredador (mosquitos - copepodos con trabajos que integren pruebas de laboratorio y de campo. Solo así será posible establecer la validez en el uso de estos últimos como controladores biológicos efectivos de mosquitos.OBJETIVE: A simulation model is presented to show the predation dynamics of Mesocyclops spp. over Aedes aegypti.i METHODS: The system is represented through four differential equations. H'(t, quantity of eggs; L'(t, quantity of larvae; A'(t, quantity of adults and C'(t, quantity of copepods. Initially the equations are of the classic predator-prey type, according to Lotka (1924 and Volterra (1926. Then it is modified into a system with functional response for invertebrates, according to Holling. RESULTS: The first system effectively controls and stabilizes the mosquito population, while the second suggests that copepods may be ineffective as mosquito controllers. CONCLUSIONS: The need to study predator-prey systems (copepodos-mosquitos with projects that integrate laboratory and of field tests is recognized. Only then will it be possible to establish the validity of predators as effective biological controllers of mosquitoes.

  1. Mosquito age and dengue transmission

    Science.gov (United States)

    The Grand Challenges in Global Health Initiative

    This online portal features a research project funded by The Grand Challenges in Global Health Initiative to develop new strategies to control mosquitoes that transmit human disease. Specifically, the project is focused on a method to reduce dengue transmission using naturally occurring bacterial symbionts that reduce mosquito life span. The site includes a background of this work, participating research programs and researchers, project publications, current progress, news and events, and FAQs.

  2. Insecticide treated mosquito nets for malaria control in India-experience from a tribal area on operational feasibility and uptake

    Scientific Electronic Library Online (English)

    P, Jambulingam; K, Gunasekaran; SS, Sahu; T, Vijayakumar.

    2008-03-01

    Full Text Available The study assessed the operational feasibility and acceptability of insecticide-treated mosquito nets (ITNs) in one Primary Health Centre (PHC) in a falciparum malaria endemic district in the state of Orissa, India, where 74% of the people are tribes and DDT indoor residual spraying had been withdra [...] wn and ITNs introduced by the National Vector Borne Disease Control Programme. To a population of 63,920, 24,442 ITNs were distributed free of charge through 101 treatment centers during July-August 2002. Interview of 1,130, 1,012 and 126 respondents showed that the net use rates were 80%, 74% and 55% in the cold, rainy and summer seasons, respectively. Since using ITNs, 74.5-76.6% of the respondents observed reduction of mosquito bites and 7.2-32.1% reduction of malaria incidence; 37% expressed willingness to buy ITNs if the cost was lower and they were affordable. Up to ten months post-treatment, almost 100% mortality of vector mosquitoes was recorded on unwashed and washed nets (once or twice). Health workers re-treated the nets at the treatment centers eight months after distribution on a cost-recovery basis. The coverage reported by the PHC was only 4.2%, mainly because of unwillingness of the people to pay for re-treatment and to go to the treatment centers from their villages. When the re-treatment was continued at the villages involving personnel from several departments, the coverage improved to about 90%.Interview of 126 respondents showed that among those who got their nets re-treated, 81.4% paid cash for the re-treatment and the remainder were reluctant to pay. Majority of those who paid said that they did so due to the fear that if they did not do so they would lose benefits from other government welfare schemes. The 2nd re-treatment was therefore carried out free of charge nine months after the 1st re-treatment and thus achieved coverage of 70.4%. The study showed community acceptance to use ITNs as they perceived the benefit. Distribution and re-treatment of nets was thus possible through the PHC system, if done free of charge and when personnel from different departments, especially those at village level, were involved.

  3. An exploratory survey of malaria prevalence and people's knowledge, attitudes and practices of mosquito larval source management for malaria control in western Kenya

    OpenAIRE

    Imbahale, S. S.; Fillinger, U.; Githeko, A.; Mukabana, W. R.; Takken, W.

    2010-01-01

    A large proportion of mosquito larval habitats in urban and rural communities in sub-Saharan Africa are man-made. Therefore, community-based larval source management (LSM) could make a significant contribution to malaria control in an integrated vector management approach. Here we implemented an exploratory study to assess malaria prevalence and people's knowledge, attitudes and practices on malaria transmission, its control and the importance of man-made aquatic habitats for the development ...

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

    OpenAIRE

    Killeen, Gerry F.; Seyoum, Aklilu; Gimnig, John E.; Stevenson, Jennifer C.; Drakeley, Christopher J.; Chitnis, Nakul

    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 bit...

  5. Oral Delivery of Double-Stranded RNA in Larvae of the Yellow Fever Mosquito, Aedes aegypti: Implications for Pest Mosquito Control

    Science.gov (United States)

    Singh, Aditi D.; Wong, Sylvia; Ryan, Calen P.; Whyard, Steven

    2013-01-01

    RNA interference has already proven itself to be a highly versatile molecular biology tool for understanding gene function in a limited number of insect species, but its widespread use in other species will be dependent on the development of easier methods of double-stranded RNA (dsRNA) delivery. This study demonstrates that RNA interference can be induced in the mosquito Aedes aegypti L. (Diptera: Culicidae) simply by soaking larvae in a solution of dsRNA for two hours. The mRNA transcripts for ?-tubulin, chitin synthase-1 and -2, and heat shock protein 83 were reduced between 30 and 50% three days post-dsRNA treatment. The dsRNA was mixed with a visible dye to identify those individuals that fed on the dsRNA, and based on an absence of RNA interference in those individuals that contained no dye within their guts, the primary route of entry of dsRNA is likely through the gut epithelium. RNA interference was systemic in the insects, inducing measurable knock down of gene expression in tissues beyond the gut. Silencing of the ?-tubulin and chitin synthase-1 genes resulted in reduced growth and/or mortality of the larvae, demonstrating the utility of dsRNA as a potential mosquito larvicide. Silencing of chitin synthase-2 did not induce mortality in the larvae, and silencing of heat shock protein 83 only induced mortality in the insects if they were subsequently subjected to a heat stress. Drosophila melanogaster Meigen (Diptera: Drosophilidae) larvae were also soaked in dsRNA designed to specifically target either their own ?-tubulin gene, or that of A. aegypti, and significant mortality was only seen in larvae treated with dsRNA targeting their own gene, which suggests that dsRNA pesticides could be designed to be species-limited. PMID:24224468

  6. Wolbachia-a foe for mosquitoes

    OpenAIRE

    Guruprasad, Nadipinayakanahalli Munikrishnappa; Jalali, Sushil Kumar; Puttaraju, Hosagavi Puttegowda

    2014-01-01

    Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmf...

  7. Ecological immunology of mosquito–malaria interactions

    OpenAIRE

    Tripet, Fre?de?ric; Aboagye-antwi, Fred; Hurd, Hilary

    2008-01-01

    More than a century after the discovery of the complex life cycle of its causative agent, malaria remains a major health problem. Understanding mosquito–malaria interactions could lead to breakthroughs in malaria control. Novel strategies, such as the design of transgenic mosquitoes refractory to Plasmodium, or design of human vaccines emulating mosquito resistance to the parasite, require extensive knowledge of processes involved in immune responses and of microevolutionary mechanisms that...

  8. Radiation biology of mosquitoes

    OpenAIRE

    Gj, Knols Bart; Parker Andrew G; Eh, Helinski Michelle

    2009-01-01

    Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage....

  9. Large-scale use of mosquito larval source management for malaria control in Africa: a cost analysis

    Directory of Open Access Journals (Sweden)

    Worrall Eve

    2011-11-01

    Full Text Available Abstract Background At present, large-scale use of two malaria vector control methods, long-lasting insecticidal nets (LLINs and indoor residual spraying (IRS is being scaled up in Africa with substantial funding from donors. A third vector control method, larval source management (LSM, has been historically very successful and is today widely used for mosquito control globally, except in Africa. With increasing risk of insecticide resistance and a shift to more exophilic vectors, LSM is now under re-evaluation for use against afro-tropical vector species. Here the costs of this intervention were evaluated. Methods The 'ingredients approach' was used to estimate the economic and financial costs per person protected per year (pppy for large-scale LSM using microbial larvicides in three ecologically diverse settings: (1 the coastal metropolitan area of Dar es Salaam in Tanzania, (2 a highly populated Kenyan highland area (Vihiga District, and (3 a lakeside setting in rural western Kenya (Mbita Division. Two scenarios were examined to investigate the cost implications of using alternative product formulations. Sensitivity analyses on product prices were carried out. Results The results show that for programmes using the same granular formulation larviciding costs the least pppy in Dar es Salaam (US$0.94, approximately 60% more in Vihiga District (US$1.50 and the most in Mbita Division (US$2.50. However, these costs are reduced substantially if an alternative water-dispensable formulation is used; in Vihiga, this would reduce costs to US$0.79 and, in Mbita Division, to US$1.94. Larvicide and staff salary costs each accounted for approximately a third of the total economic costs per year. The cost pppy depends mainly on: (1 the type of formulation required for treating different aquatic habitats, (2 the human population density relative to the density of aquatic habitats and (3 the potential to target the intervention in space and/or time. Conclusion Costs for LSM compare favourably with costs for IRS and LLINs, especially in areas with moderate and focal malaria transmission where mosquito larval habitats are accessible and well defined. LSM presents an attractive tool to be integrated in ongoing malaria control effort in such settings. Further data on the epidemiological health impact of larviciding is required to establish cost effectiveness.

  10. Controle de mosquitos com base em larvicidas no Estado do Rio Grande do Sul, Brasil: a escolha do agente de controle

    Directory of Open Access Journals (Sweden)

    Ruas-Neto Antônio L.

    1994-01-01

    Full Text Available Desenvolveu-se neste estudo uma comparação entre larvicidas químicos e biológicos usados em programas de controle de mosquitos no Rio Grande do Sul. Em bioensaios de laboratório contra Culex quinquefasciatus constatou-se que as formulações biológicas líquidas Vectobac 12 AS e Teknar 3000 (Bacillus thuringiensis israelensis, ABG 6262 líquido e em pó (B. sphaericus 2362, foram altamente eficazes. Também as formulações experimentais de B. thuringiensis israelensis produzidas em laboratórios brasileiros foram consideradas adequadas. Entre as formulações químicas, os compostos piretróides Pirisa e K-Othrine produziram resultados melhores do que os organo-fosforados Lebaycid e Abate. Estes últimos produziram respostas dez vezes mais fracas do que o previsto em outros estudos. Em condições de campo, a dose de 1250 mg/m² para as formulações biológicas foi considerada adequada para a rotina das aplicações, porque permite superar as influências físicas do meio sobre os resultados. Somente as formulações de B. sphaericus produziram interrupções nas reinfestações dos focos de culicídeos observados. Períodos de até 39 semanas sem reinfestações foram observados em focos naturais e de um mês sem sobrevivência foi observado em tanques, onde procedia-se a reinfestação artificial. Este estudo sugere que as alternativas biológicas devem ser consideradas em programas de controle de mosquitos. Elas podem superar os problemas de resistência e eliminação, bem como da ausência de efeito residual nas aplicações de larvicidas.

  11. Anthropogenic ecological change and impacts on mosquito breeding and control strategies in salt-marshes, Northern Territory, Australia.

    Science.gov (United States)

    Jacups, Susan; Warchot, Allan; Whelan, Peter

    2012-06-01

    Darwin, in the tropical north of Australia, is subject to high numbers of mosquitoes and several mosquito-borne diseases. Many of Darwin's residential areas were built in close proximity to tidally influenced swamps, where long-term storm-water run-off from nearby residences into these swamps has led to anthropogenic induced ecological change. When natural wet-dry cycles were disrupted, bare mud-flats and mangroves were transformed into perennial fresh to brackish-water reed swamps. Reed swamps provided year-round breeding habitat for many mosquito species, such that mosquito abundance was less predictable and seasonally dependent, but constant and often occurring in plague proportions. Drainage channels were constructed throughout the wetlands to reduce pooled water during dry-season months. This study assesses the impact of drainage interventions on vegetation and mosquito ecology in three salt-marshes in the Darwin area. Findings revealed a universal decline in dry-season mosquito abundance in each wetland system. However, some mosquito species increased in abundance during wet-season months. Due to the high expense and potentially detrimental environmental impacts of ecosystem and non-target species disturbance, large-scale modifications such as these are sparingly undertaken. However, our results indicate that some large scale environmental modification can assist the process of wetland restoration, as appears to be the case for these salt marsh systems. Drainage in all three systems has been restored to closer to their original salt-marsh ecosystems, while reducing mosquito abundances, thereby potentially lowering the risk of vector-borne disease transmission and mosquito pest biting problems. PMID:22476689

  12. Beyond buzzing: mosquito watching stimulates malaria bednet use—a household-based cluster-randomized controlled assessor blind educational trial

    OpenAIRE

    Hoshi, Tomonori; Martin Banda, Paul; Foster Pemba, Dylo; Sunahara, Toshihiko; MINAKAWA, NOBORU

    2013-01-01

    Malaria remains a severe health problem in Sub-Saharan Africa, with approximately one million deaths and 365 million cases each year. In terms of malaria control, insecticide-treated bednets are an effective tool, and many organizations have distributed free or highly subsidized bednets in malaria endemic areas. Nevertheless, some recipients do not use bednets because of social, environmental or cultural factors. Making vulnerable populations aware of the presence of mosquitoes may improve be...

  13. An exploratory survey of malaria prevalence and people's knowledge, attitudes and practices of mosquito larval source management for malaria control in western Kenya.

    Science.gov (United States)

    Imbahale, S S; Fillinger, U; Githeko, A; Mukabana, W R; Takken, W

    2010-09-01

    A large proportion of mosquito larval habitats in urban and rural communities in sub-Saharan Africa are man-made. Therefore, community-based larval source management (LSM) could make a significant contribution to malaria control in an integrated vector management approach. Here we implemented an exploratory study to assess malaria prevalence and people's knowledge, attitudes and practices on malaria transmission, its control and the importance of man-made aquatic habitats for the development of disease vectors in one peri-urban lowland and two rural highland communities in western Kenya. We implemented monthly cross-sectional malaria surveys and administered a semi-structured questionnaire in 90 households, i.e. 30 households in each locality. Malaria prevalence was moderate (3.2-6.5%) in all sites. Nevertheless, residents perceived malaria as their major health risk. Thirty-two percent (29/90) of all respondents did not know that mosquitoes are responsible for the transmission of malaria. Over two-thirds (69/90) of the respondents said that mosquito breeding site could be found close to their homes but correct knowledge of habitat characteristics was poor. Over one-third (26/67) believed that immature mosquitoes develop in vegetation. Man-made pools, drainage channels and burrow pits were rarely mentioned. After explaining where mosquito larvae develop, 56% (50/90) felt that these sites were important for their livelihood. Peri-urban residents knew more about mosquitoes' role in malaria transmission, could more frequently describe the larval stages and their breeding habitats, and were more likely to use bed nets even though malaria prevalence was only half of what was found in the rural highland sites (pSustainable elimination or rendering of such habitats unsuitable for larval development needs horizontally organized, community-based programs that take people's needs into account. Innovative, community-based training programs need to be developed to increase people's awareness of man-made vector breeding sites and acceptable control methods need to be designed in collaboration with the communities. PMID:20399739

  14. Oral toxicity of Bacillus thuringiensis subsp. israelensis to adult mosquitoes.

    OpenAIRE

    Klowden, M J; Bulla, L. A.

    1984-01-01

    The solubilized entomotoxin of Bacillus thuringiensis subsp. israelensis killed adult male and female mosquitoes of several genera and of various physiological states when it was administered orally. Adult mosquito mortality was further influenced when the preparation was contained in sucrose solution. The potential implication for the control of adult mosquitoes is discussed.

  15. Bioactive compound synthesis of Ag nanoparticles from leaves of Melia azedarach and its control for mosquito larvae.

    Science.gov (United States)

    Ramanibai, R; Velayutham, K

    2015-02-01

    Larvicidal activity of synthesized Ag nanoparticles using 2,7.bis[2-[diethylamino]-ethoxy]fluorence isolate from the Melia azedarach leaves against Aedes aegypti and Culex quinquefasciatus. Six fractions were collected and concentrated, fraction three showed a single spot on TLC which was found to be a pure compound. The structures were elucidated by analyses of UV, MS, and NMR spectral data. The maximum mortality was fluorence against A.?aegypti and C.?quinquefasciatus (LC50?=?7.94, LC90?=?23.82?ppm and LC50?=?13.58 and LC90?=?40.03?ppm). The synthesized nanoparticles were characterized and confirmed as Ag nanoparticles by using UV-visible spectroscopy, XRD and HRTEM analysis. The maximum activity was observed in synthesized AgNPs against A.?aegypti and C.?quinquefasciatus (LC50?=?4.27 and 3.43?µg/mL; LC90?=?12.61 and 10.29?µg/mL). Rephrase test was studied to analyze the toxicological effects of Mesocyclops pehpeiensis for 24?h at synthesized AgNPs. This method is considered as an innovative alternative approach that can be used to control mosquitoes. PMID:25496834

  16. Survey of Bancroftian filariasis infection in humans and Culex mosquitoes in the western Brazilian Amazon region: implications for transmission and control

    Scientific Electronic Library Online (English)

    Rodolfo Luís, Korte; Gilberto, Fontes; Juliana de Souza Almeida Aranha, Camargo; Eliana Maria Maurício da, Rocha; Edicarlos André Cavalcante de, Araújo; Marcelo Zagonel de, Oliveira; Rafael Vital dos, Santos; Luís Marcelo Aranha, Camargo.

    2013-04-01

    Full Text Available Introduction The aim of this work was to identify possible lymphatic filariasis foci in the western Brazilian Amazonian that could be established from the reports of Rachou in the 1950s. The study was conducted in three cities of the western Brazilian Amazon region - Porto Velho and Guaja [...] rá-Mirim (State of Rondônia) and Humaitá (State of Amazonas). Methods For human infection evaluation thick blood smear stained with Giemsa was used to analyze samples collected from 10pm to 1am. Polymerase chain reaction (PCR) was used to examine mosquito vectors for the presence of Wuchereria bancrofti DNA. Humans were randomly sampled from night schools students and from inhabitants in neighborhoods lacking sanitation. Mosquitoes were collected from residences only. Results A total 2,709 night students enrolled in the Program for Education of Young Adults (EJA), and 935 people registered in the residences near the schools were examined, being 641 from Porto Velho, 214 from Guajará-Mirim and 80 from Humaitá. No individual examined was positive for the presence of microfilariae in the blood stream. A total of 7,860 female Culex quinquefasciatus specimens examined were negative by PCR. Conclusions This survey including human and mosquito examinations indicates that the western Amazon region of Brazil is not a focus of Bancroftian filariasis infection or transmission. Therefore, there is no need to be included in the Brazilian lymphatic filariasis control program.

  17. Survey of Bancroftian filariasis infection in humans and Culex mosquitoes in the western Brazilian Amazon region: implications for transmission and control

    Directory of Open Access Journals (Sweden)

    Rodolfo Luís Korte

    2013-04-01

    Full Text Available Introduction The aim of this work was to identify possible lymphatic filariasis foci in the western Brazilian Amazonian that could be established from the reports of Rachou in the 1950s. The study was conducted in three cities of the western Brazilian Amazon region - Porto Velho and Guajará-Mirim (State of Rondônia and Humaitá (State of Amazonas. Methods For human infection evaluation thick blood smear stained with Giemsa was used to analyze samples collected from 10pm to 1am. Polymerase chain reaction (PCR was used to examine mosquito vectors for the presence of Wuchereria bancrofti DNA. Humans were randomly sampled from night schools students and from inhabitants in neighborhoods lacking sanitation. Mosquitoes were collected from residences only. Results A total 2,709 night students enrolled in the Program for Education of Young Adults (EJA, and 935 people registered in the residences near the schools were examined, being 641 from Porto Velho, 214 from Guajará-Mirim and 80 from Humaitá. No individual examined was positive for the presence of microfilariae in the blood stream. A total of 7,860 female Culex quinquefasciatus specimens examined were negative by PCR. Conclusions This survey including human and mosquito examinations indicates that the western Amazon region of Brazil is not a focus of Bancroftian filariasis infection or transmission. Therefore, there is no need to be included in the Brazilian lymphatic filariasis control program.

  18. Molecular Analysis of Aedes aegypti Classical Protein Tyrosine Phosphatases Uncovers an Ortholog of Mammalian PTP-1B Implicated in the Control of Egg Production in Mosquitoes

    Science.gov (United States)

    Moretti, Debora Monteiro; Ahuja, Lalima Gagan; Nunes, Rodrigo Dutra; Cudischevitch, Cecília Oliveira; Daumas-Filho, Carlos Renato Oliveira; Medeiros-Castro, Priscilla; Ventura-Martins, Guilherme; Jablonka, Willy; Gazos-Lopes, Felipe; Senna, Raquel; Sorgine, Marcos Henrique Ferreira; Hartfelder, Klaus; Capurro, Margareth; Atella, Georgia Correa; Mesquita, Rafael Dias; Silva-Neto, Mário Alberto Cardoso

    2014-01-01

    Background Protein Tyrosine Phosphatases (PTPs) are enzymes that catalyze phosphotyrosine dephosphorylation and modulate cell differentiation, growth and metabolism. In mammals, PTPs play a key role in the modulation of canonical pathways involved in metabolism and immunity. PTP1B is the prototype member of classical PTPs and a major target for treating human diseases, such as cancer, obesity and diabetes. These signaling enzymes are, hence, targets of a wide array of inhibitors. Anautogenous mosquitoes rely on blood meals to lay eggs and are vectors of the most prevalent human diseases. Identifying the mosquito ortholog of PTP1B and determining its involvement in egg production is, therefore, important in the search for a novel and crucial target for vector control. Methodology/Principal Findings We conducted an analysis to identify the ortholog of mammalian PTP1B in the Aedes aegypti genome. We identified eight genes coding for classical PTPs. In silico structural and functional analyses of proteins coded by such genes revealed that four of these code for catalytically active enzymes. Among the four genes coding for active PTPs, AAEL001919 exhibits the greatest degree of homology with the mammalian PTP1B. Next, we evaluated the role of this enzyme in egg formation. Blood feeding largely affects AAEL001919 expression, especially in the fat body and ovaries. These tissues are critically involved in the synthesis and storage of vitellogenin, the major yolk protein. Including the classical PTP inhibitor sodium orthovanadate or the PTP substrate DiFMUP in the blood meal decreased vitellogenin synthesis and egg production. Similarly, silencing AAEL001919 using RNA interference (RNAi) assays resulted in 30% suppression of egg production. Conclusions/Significance The data reported herein implicate, for the first time, a gene that codes for a classical PTP in mosquito egg formation. These findings raise the possibility that this class of enzymes may be used as novel targets to block egg formation in mosquitoes. PMID:25137153

  19. Genetically Modified Mosquito: Myth and Reality

    OpenAIRE

    Teh Su Yean; Koh Hock Lye; Yeap Kiew Lee

    2013-01-01

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

  20. Free flight of the mosquito Aedes aegypti

    CERN Document Server

    Iams, S M

    2012-01-01

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

  1. Development of Metarhizium anisopliae and Beauveria bassiana formulations for control of malaria mosquito larvae

    OpenAIRE

    Takken Willem; Bukhari Tullu; Koenraadt Constantianus JM

    2011-01-01

    Abstract Background The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana have demonstrated effectiveness against anopheline larvae in the laboratory. However, utilising these fungi for the control of anopheline larvae under field conditions, relies on development of effective means of application as well as reducing their sensitivity to UV radiation, high temperatures and the inevitable contact with water. This study was conducted to develop formulations that facilitate th...

  2. Circadian control of permethrin-resistance in the mosquito Aedes aegypti.

    Czech Academy of Sciences Publication Activity Database

    Yang, Y.-Y.; Liu, Y.; Teng, H.-J.; Šauman, Ivo; Sehnal, František; Lee, H.-J.

    2010-01-01

    Ro?. 56, ?. 9 (2010), s. 1219-1223. ISSN 0022-1910 R&D Projects: GA MŠk LC07032 Grant ostatní: Centers for Disease Control, Department of Health(TW) DOH96-DC-1206; National Science Council(TW) NSC 95-2313-B-002-084 MY3 Institutional research plan: CEZ:AV0Z50070508 Keywords : insecticide resistence * median knock-down time * clock gene Subject RIV: ED - Physiology Impact factor: 2.310, year: 2010

  3. Toxicological effects of prolonged and intense use of mosquito coil emission in rats and its implications on malaria control / Efectos toxicológicos del uso prolongado e intenso de emisiones de espirales contra mosquitos en ratas y sus implicaciones sobre el control de la malaria

    Scientific Electronic Library Online (English)

    Emmanuel, Taiwo Idowu; Oyenmwen Judith, Aimufua; Ejovwoke, Yomi-Onilude; Bamidele, Akinsanya; Olubumi, Adetoro Otubanjo.

    1463-14-01

    Full Text Available Las espirales contra los mosquitos se utilizan en los países de bajos ingresos como una opción para prevenir la malaria controlando el vector de esta enfermedad. A pesar de que algunos estudios han abordado este tema, se requiere más investigación para incrementar el conocimiento sobre los efectos a [...] dversos en la salud, causados por el uso prolongado de las espirales. En este estudio se investigaron los efectos toxicológicos de los gases de las espirales a partir de dos insecticidas fabricados en el país (con piretroides: transflutrina y d-aletrina como ingredientes activos) en machos de ratas albinas. Para esto, se registraron los índices hematológicos y bioquímicos, y se hicieron evaluaciones histopatológicas y de mutagenicidad en ratas expuestas a los gases de las espirales durante períodos de 2, 4, 8, 12 y 16 semanas. La determinación hematológica se realizó mediante un analizador de hematología automatizado para determinar el conteo de los Glóbulos Blancos (WBC), el Hematocrito (PCV), Glóbulos Rojos (RBC) y las Plaquetas (PLT), mientras que las evaluaciones bioquímicas se determinaron utilizando kits comerciales disponibles. Los cambios histopatológicos fuertes se estudiaron en el riñón, el hígado y los pulmones de ratas sacrificadas. Las anormalidades en la cabeza de los espermatozoides de las ratas se utilizaron para evaluar la mutagenicidad. El humo de las espirales contra los mosquitos producen un aumento significativo (p0.05). Las pruebas de mutagenicidad revelaron que las anormalidades en el esperma de las ratas fue estadísticamente significativa (p>0.05) al comparar el control a las 8, 12 y 16 semanas post exposición a la transflutrina. Los estudios histológicos revelaron una serie de daños pulmonares graves en las ratas expuestas al humo de la espiral, evidenciados por la acumulación intersticial, edema pulmonar y enfisema. Las acumulaciones intracelulares y la congestión sinusoidal severa de las células del hígado se observaron a partir de las 12 semanas de exposición, lo que indica daño hepático. Nuestros estudios indican que los vapores de las espirales contra mosquitos inician el daño gradual al huésped. Estos efectos patológicos deben ser tomados en cuenta por el programa de control de la malaria, particularmente a la hora de regular su uso a largo plazo y bajo techo. Abstract in english Efectos toxicológicos del uso prolongado e intenso de emisiones de espirales contra mosquitos en ratas y sus implicaciones sobre el control de la malaria. Mosquito coil is a vector control option used to prevent malaria in low income counties, while some studies have addressed this issue, additional [...] reseach is required to increase knowledge on the adverse health effects caused by the prolonged use of coils. In this study we investigated the toxicological effects of fumes from two locally manufactured mosquito coil insecticides (with pyrethroids: transfluthrin and d-allethrin as active ingredients) on male albino rats. For this, we recorded the haematological and biochemical indices, and made histopathology and mutagenicity evaluations in rats exposed to mosquito fumes during 2, 4, 8, 12 and 16 week periods. Haematological determination was performed using automated hematology analyzer to determine White Blood Cell (WBC), Packed Cell Volume (PCV), Red Blood Cell (RBC) and Platelet (PLT) counts, while biochemical evaluations were determined using available commercial kits. Gross histopathological changes were studied for the kidney, liver and lungs in sacrificed rats. The rat sperm head abnormalities assessment was used to evaluate mutagenicity. Mosquito coil fumes produced significant increase (P0.05). Mutagenicity assessment revealed sperm abnormality was statistically significant (P

  4. Micro-lipid-droplet encapsulation of Bacillus thuringiensis subsp. israelensis delta-endotoxin for control of mosquito larvae.

    OpenAIRE

    Cheung, P Y; Hammock, B D

    1985-01-01

    The crystal delta-endotoxin of Bacillus thuringiensis subsp. israelensis is less toxic to larvae of Anopheles freeborni than to larvae of Aedes aegypti. However, when solubilized crystal was used, larvae from both species showed similar sensitivities. This effect presumably was due to the differences in feeding behavior between the two mosquito larvae when crystal preparations are used. A procedure is described whereby both crystal and solubilized B. thuringiensis subsp. israelensis toxin wer...

  5. Preliminary evaluation of mosquito larvicidal efficacy of plant extracts

    OpenAIRE

    N.G. Das, D. Goswami & B. Rabha

    2007-01-01

    Mosquitoes are the most important single group ofinsects in terms of public health importance, whichtransmit a number of diseases, such as malaria, filariasis,dengue, Japanese encephalitis, etc. causing millionsof deaths every year. Repeated use of syntheticinsecticides for mosquito control has disrupted naturalbiological control systems and led to resurgencesin mosquito populations. It has also resulted in thedevelopment of resistance1, undesirable effects onnon-target organisms and fostered...

  6. Plectranthus amboinicus leaf extract mediated synthesis of zinc oxide nanoparticles and its control of methicillin resistant Staphylococcus aureus biofilm and blood sucking mosquito larvae

    Science.gov (United States)

    Vijayakumar, S.; Vinoj, G.; Malaikozhundan, B.; Shanthi, S.; Vaseeharan, B.

    2015-02-01

    In this study, zinc oxide nanoparticles were biologically synthesized using the leaf extract of Plectranthus amboinicus (Pam-ZnO NPs). The synthesized Pam-ZnO NPs were characterized by UV-Vis spectrophotometer, FTIR, TEM and XRD analysis. TEM analysis of Pam-ZnO NPs showed the average size of about 20-50 nm. Pam-ZnO NPs control the growth of methicillin-resistant Staphylococcus aureus biofilms (MRSA ATCC 33591) at the concentration of 8-10 ?g/ml. Confocal laser scanning microscope (CLSM) images revealed that Pam-ZnO NPs strongly inhibited the biofilm forming ability of S. aureus. In addition, Pam-ZnO NPs showed 100% mortality of fourth instar mosquito larvae of Anopheles stephensi, Culex quinquefasciatus and Culex tritaeniorhynchus at the concentration of 8 and 10 ?g/ml. The histopathological studies of Pam-ZnO NPs treated A. stephensi and C. quinquefasciatus larvae revealed the presence of damaged cells and tissues in the mid-gut. The damaged tissues suffered major changes including rupture and disintegration of epithelial layer and cellular vacuolization. The present study conclude that Pam-ZnO NPs showed effective control of S. aureus biofilms and mosquito larvae by damaging the mid gut cells.

  7. Evaluation of AaDOP2 receptor antagonists reveals antidepressants and antipsychotics as novel lead molecules for control of the yellow fever mosquito, Aedes aegypti.

    Science.gov (United States)

    Conley, Jason M; Meyer, Jason M; Nuss, Andrew B; Doyle, Trevor B; Savinov, Sergey N; Hill, Catherine A; Watts, Val J

    2015-01-01

    The yellow fever mosquito, Aedes aegypti, vectors disease-causing agents that adversely affect human health, most notably the viruses causing dengue and yellow fever. The efficacy of current mosquito control programs is challenged by the emergence of insecticide-resistant mosquito populations, suggesting an urgent need for the development of chemical insecticides with new mechanisms of action. One recently identified potential insecticide target is the A. aegypti D1-like dopamine receptor, AaDOP2. The focus of the present study was to evaluate AaDOP2 antagonism both in vitro and in vivo using assay technologies with increased throughput. The in vitro assays revealed AaDOP2 antagonism by four distinct chemical scaffolds from tricyclic antidepressant or antipsychotic chemical classes, and elucidated several structure-activity relationship trends that contributed to enhanced antagonist potency, including lipophilicity, halide substitution on the tricyclic core, and conformational rigidity. Six compounds displayed previously unparalleled potency for in vitro AaDOP2 antagonism, and among these, asenapine, methiothepin, and cis-(Z)-flupenthixol displayed subnanomolar IC50 values and caused rapid toxicity to A. aegypti larvae and/or adults in vivo. Our study revealed a significant correlation between in vitro potency for AaDOP2 antagonism and in vivo toxicity, suggesting viability of AaDOP2 as an insecticidal target. Taken together, this study expanded the repertoire of known AaDOP2 antagonists, enhanced our understanding of AaDOP2 pharmacology, provided further support for rational targeting of AaDOP2, and demonstrated the utility of efficiency-enhancing in vitro and in vivo assay technologies within our genome-to-lead pipeline for the discovery of next-generation insecticides. PMID:25332454

  8. Ecology of mosquitoes of Midwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Godwin R.A. Okogun, Jude C. Anosike, Anthony N. Okere & Bethran E.B. Nwoke

    2005-03-01

    Full Text Available Background & objectives: The ecology and distribution of various mosquito species is important inthe determination of mosquito vector abundance and associated diseases prevalence. The distributionof various mosquito genera in natural and artificial habitats and their relative species abundancewas studied between August 2002 and July 2003 in three foci (Uromi, Ekpoma and Auchi comprisingthe Esan and Etsako regions of Midwestern Nigeria.Methods: Sampling was carried out by the method of Hopkins (1952 by dipping using a pipette orladle depending on container types. Pooled contents of smaller containers were sampled with a pondnet. All breeding sources of mosquito larvae were grouped into five (5 depending on their nature,constitution and the physiochemical properties. Artificial mosquito cultures were also carried out infour different container types; plastics, metal cans, earthenware pots and bamboo strips, in parts oftwo different macro habitats subdivided into area of high human activities (AHHA and areas ofderived/secondary vegetation (ADSV. Environmental temperatures, rainfall and relative humiditywere monitored during the study.Results: The present study revealed 17 mosquito species belonging to three genera (Anopheles,Culex and Aedes which are potential vectors of four human diseases in the areas surveyed. A total of736 mosquito larvae were encountered in artificial sources and 568 larvae were harvested from naturalsources. Pools, plastics and metal cans were the predominant artificial sources of mosquito larvae.Conclusion: The contribution of human activities and increasing environmental modification to thebreeding of human disease vector mosquitoes is of importance and selective vector control measuresincluding larviciding are recommended particularly before onset of rainy season

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

    Science.gov (United States)

    Ahmed, Mohamed Ahmed Ibrahim; Vogel, Christoph Franz Adam

    2015-05-01

    Studying insecticide resistance in mosquitoes has attracted the attention of many scientists to elucidate the pathways of resistance development and to design novel strategies in order to prevent or minimize the spread and evolution of resistance. Here, we tested the synergistic action of piperonyl butoxide (PBO) and two octopamine receptor (OR) agonists, amitraz (AMZ) and chlordimeform (CDM) on selected novel insecticides to increase their lethal action on the fourth instar larvae of Aedes aegypti L. However, chlorfenapyr was the most toxic insecticide (LC50?=?193, 102, and 48?ng/ml, after 24, 48, and 72?h exposure, respectively) tested. Further, PBO synergized all insecticides and the most toxic combinatorial insecticide was nitenpyram even after 48 and 72?h exposure. In addition, OR agonists significantly synergized most of the selected insecticides especially after 48 and 72?h exposure. The results imply that the synergistic effects of amitraz are a promising approach in increasing the potency of certain insecticides in controlling the dengue vector Ae. aegypti mosquito. PMID:25987220

  10. La Crosse virus nucleocapsid protein controls its own synthesis in mosquito cells by encapsidating its mRNA.

    OpenAIRE

    Hacker, D.; Raju, R.; Kolakofsky, D.

    1989-01-01

    Within 24 to 48 h of La Crosse virus infection of mosquito cells, greater than 75% of the S mRNA was found to band in CsCl density gradients at the position of genome or antigenome nucleocapsids. The encapsidation of the S mRNA correlates with the repression of N protein synthesis in vivo, and the encapsidated S mRNA cannot be translated in vitro. Unlike genome and antigenome assembly, S mRNA assembly is a relatively slow process, which is not coupled to its synthesis. Within the encapsidated...

  11. Outdoor host seeking behaviour of Anopheles gambiae mosquitoes following initiation of malaria vector control on Bioko Island, Equatorial Guinea

    Directory of Open Access Journals (Sweden)

    Reddy Vamsi P

    2011-07-01

    Full Text Available Abstract Background Indoor-based anti-vector interventions remain the preferred means of reducing risk of malaria transmission in malaria endemic areas around the world. Despite demonstrated success in reducing human-mosquito interactions, these methods are effective solely against endophilic vectors. It may be that outdoor locations serve as an important venue of host seeking by Anopheles gambiae sensu lato (s.l. mosquitoes where indoor vector suppression measures are employed. This paper describes the host seeking activity of anopheline mosquito vectors in the Punta Europa region of Bioko Island, Equatorial Guinea. In this area, An. gambiae sensu stricto (s.s. is the primary malaria vector. The goal of the paper is to evaluate the importance of An gambiae s.l. outdoor host seeking behaviour and discuss its implications for anti-vector interventions. Methods The venue and temporal characteristics of host seeking by anopheline vectors in a hyperendemic setting was evaluated using human landing collections conducted inside and outside homes in three villages during both the wet and dry seasons in 2007 and 2008. Additionally, five bi-monthly human landing collections were conducted throughout 2009. Collections were segregated hourly to provide a time distribution of host-seeking behaviour. Results Surprisingly high levels of outdoor biting by An. gambiae senso stricto and An. melas vectors were observed throughout the night, including during the early evening and morning hours when human hosts are often outdoors. As reported previously, An. gambiae s.s. is the primary malaria vector in the Punta Europa region, where it seeks hosts outdoors at least as much as it does indoors. Further, approximately 40% of An. gambiae s.l. are feeding at times when people are often outdoors, where they are not protected by IRS or LLINs. Repeated sampling over two consecutive dry-wet season cycles indicates that this result is independent of seasonality. Conclusions An. gambiae s.l. mosquitoes currently seek hosts in outdoor venues as much as indoors in the Punta Europa region of Bioko Island. This contrasts with an earlier pre-intervention observation of exclusive endophagy of An. gambiae in this region. In light of this finding, it is proposed that the long term indoor application of insecticides may have resulted in an adaptive shift toward outdoor host seeking in An. gambiae s.s. on Bioko Island.

  12. Do malaria parasites manipulate mosquitoes?

    OpenAIRE

    Cator, Lauren J; Lynch, Pennelope A.; Read, Andrew F.; Matthew B. Thomas

    2012-01-01

    Malaria parasites have been suggested to alter the behavior of mosquito vectors to increase the likelihood of transmission. Some empirical evidence supports this hypothesis, yet the role of manipulation is ignored in most epidemiological models, and behavioral differences between infected and uninfected females are not considered in the development or implementation of control measures. We suggest that this disconnect exists because the link between behavioral alteration and actual transmissi...

  13. Eficiencia del Galgotrin 25 EC, Terfos 48 EC, Lambdacialotrina 2,5 EC e Icon 2,5 EC en el control del mosquito Aedes aegypti en el Municipio Santiago de Cuba, Cuba Efficiency of Galgothrin 25 EC, Terfos 48 EC, Lambdacyhalothrin 2,5 EC and Icon 2,5 EC for the control of Aedes aegypti mosquitoes in Santiago de Cuba municipality

    Directory of Open Access Journals (Sweden)

    Domingo Montada Dorta

    2008-04-01

    Full Text Available INTRODUCCIÓN: en las epidemias o brotes de dengue los plaguicidas químicos desempeñan un papel fundamental para controlar los mosquitos adultos transmisores de la enfermedad, y como sostén del Programa de control del vector en Cuba. OBJETIVO: se realizó una investigación para conocer la efectividad y la eficiencia de las formulaciones de insecticidas en uso en el control del mosquito Aedes aegypti en la provincia Santiago de Cuba, y así trazar las estrategias de su uso. MÉTODOS: los bioensayos se realizaron de acuerdo con la metodología de la OMS. Se comparó la eficacia y eficiencia entre los tratamientos de nebulizacion en frío y los de termonebulizacion con los insecticidas estudiados, mediante una prueba U de Mann Whitney. El análisis comparativo de la eficiencia entre tratamientos y cada formulación se realizó mediante una prueba de Kruskal-Wallis. RESULTADOS: al comparar las mortalidades obtenidas con ambos tratamientos se demostró que existe una diferencia altamente significativa entre ellos a favor de los tratamientos de termonebulización, lo que demuestra la eficacia de este último y su eficiencia (efectividad/costo. CONCLUSIONES: con la prueba de Kruskal-Wallis se demostró que existe una diferencia altamente significativa entre las formulaciones a favor del Galgotrin 25 EC, que es más eficiente sin DDVP.INTRODUCTION: In dengue epidemics or outbreaks, insecticides play an important role in controlling adult mosquitoes and in supporting the vector control program in Cuba. OBJECTIVE: To find out the effectiveness and efficiency of insecticidal formulae for Aedes aegypti mosquito control in Santiago de Cuba province and to draw up the strategies for use. METHODS: Bioassays were performed according to the WHO methodology. The efficacy and efficiency of cold fogging and thermal fogging methods were compared through Mann Whitney´s U test. The comparative analysis of the efficiency of both methods and every formulation was made using Kruskal-Wallis test. RESULTS: When comparing the mortality indexes from both methods, it was observed that there was a highly significant difference between them, being the thermal fogging method the most useful because of its efficacy and efficiency (cost effectiveness. CONCLUSIONS: Kruskal-Wallis test proved that there is a highly significant difference among the various formulations. Galgothrin 25 EC is the most favourable and efficient without DDVP.

  14. Eficiencia del Galgotrin 25 EC, Terfos 48 EC, Lambdacialotrina 2,5 EC e Icon 2,5 EC en el control del mosquito Aedes aegypti en el Municipio Santiago de Cuba, Cuba / Efficiency of Galgothrin 25 EC, Terfos 48 EC, Lambdacyhalothrin 2,5 EC and Icon 2,5 EC for the control of Aedes aegypti mosquitoes in Santiago de Cuba municipality

    Scientific Electronic Library Online (English)

    Domingo, Montada Dorta; Ivón, Calderón Morales; Daisy, Figueredo Sánchez; Eugenio, Soto Cisneros; Maureen, Leyva Silva.

    2008-04-01

    Full Text Available INTRODUCCIÓN: en las epidemias o brotes de dengue los plaguicidas químicos desempeñan un papel fundamental para controlar los mosquitos adultos transmisores de la enfermedad, y como sostén del Programa de control del vector en Cuba. OBJETIVO: se realizó una investigación para conocer la efectividad [...] y la eficiencia de las formulaciones de insecticidas en uso en el control del mosquito Aedes aegypti en la provincia Santiago de Cuba, y así trazar las estrategias de su uso. MÉTODOS: los bioensayos se realizaron de acuerdo con la metodología de la OMS. Se comparó la eficacia y eficiencia entre los tratamientos de nebulizacion en frío y los de termonebulizacion con los insecticidas estudiados, mediante una prueba U de Mann Whitney. El análisis comparativo de la eficiencia entre tratamientos y cada formulación se realizó mediante una prueba de Kruskal-Wallis. RESULTADOS: al comparar las mortalidades obtenidas con ambos tratamientos se demostró que existe una diferencia altamente significativa entre ellos a favor de los tratamientos de termonebulización, lo que demuestra la eficacia de este último y su eficiencia (efectividad/costo). CONCLUSIONES: con la prueba de Kruskal-Wallis se demostró que existe una diferencia altamente significativa entre las formulaciones a favor del Galgotrin 25 EC, que es más eficiente sin DDVP. Abstract in english INTRODUCTION: In dengue epidemics or outbreaks, insecticides play an important role in controlling adult mosquitoes and in supporting the vector control program in Cuba. OBJECTIVE: To find out the effectiveness and efficiency of insecticidal formulae for Aedes aegypti mosquito control in Santiago de [...] Cuba province and to draw up the strategies for use. METHODS: Bioassays were performed according to the WHO methodology. The efficacy and efficiency of cold fogging and thermal fogging methods were compared through Mann Whitney´s U test. The comparative analysis of the efficiency of both methods and every formulation was made using Kruskal-Wallis test. RESULTS: When comparing the mortality indexes from both methods, it was observed that there was a highly significant difference between them, being the thermal fogging method the most useful because of its efficacy and efficiency (cost effectiveness). CONCLUSIONS: Kruskal-Wallis test proved that there is a highly significant difference among the various formulations. Galgothrin 25 EC is the most favourable and efficient without DDVP.

  15. Potential Use of Mosquito’s Salivary Components as Novel Target for The Development of Transmission Blocking Vaccine (TBV)

    OpenAIRE

    KARTIKA SENJARINI

    2013-01-01

    Mosquito-borne diseases are rampant in most tropical regions of the world, especially rural, forested, and coastal areas such as Indonesia. Despite long-standing chemotherapeutic intercession and vector control programs, mosquito-borne diseases exact a heavy burden on human health in Indonesia. Two major public health problems transmitted by mosquito in Indonesia are malaria and dengue haemorrhagic fever (DHF), causing millions of clinical episodes occurring annu...

  16. Quantitative Trait Loci Controlling Refractoriness to Plasmodium falciparum in Natural Anopheles gambiae Mosquitoes From a Malaria-Endemic Region in Western Kenya

    OpenAIRE

    Menge, David M.; Zhong, Daibin; Guda, Tom; Gouagna, Louis; Githure, John; Beier, John; Yan, Guiyun

    2006-01-01

    Natural anopheline populations exhibit much variation in ability to support malaria parasite development, but the genetic mechanisms underlying this variation are not clear. Previous studies in Mali, West Africa, identified two quantitative trait loci (QTL) in Anopheles gambiae mosquitoes that confer refractoriness (failure of oocyst development in mosquito midguts) to natural Plasmodium falciparum parasites. We hypothesize that new QTL may be involved in mosquito refractoriness to malaria pa...

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

    OpenAIRE

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

    2014-01-01

    Dengue is a tropical, potentially lethal disease transmitted by mosquitoes. A new control method involves the release of mosquitoes infected by the bacterium Wolbachia that blocks the transmission of the dengue virus to humans. However, possible negative effects of Wolbachia on mosquito reproductive success could substantially slow the spread of this bacterium in mosquito populations, reducing the feasibility of this method. We found that male mosquitoes infected by Wolbachia are equally succ...

  18. Evaluation of a Stable Isotope Method to Mark Naturally-Breeding Larval Mosquitoes for Adult Dispersal Studies

    OpenAIRE

    Hamer, Gabriel L.; Donovan, Danielle J.; Hood-Nowotny, Rebecca; KAUFMAN, MICHAEL G.; GOLDBERG, TONY L.; WALKER, EDWARD D.

    2012-01-01

    Understanding mosquito dispersal is critically important for vector-borne disease control and prevention. Mark–release–recapture methods using various marking techniques have made substantial contributions to the study of mosquito biology. However, the ability to mark naturally breeding mosquitoes noninvasively and with life-long retention has remained problematic. Here, we describe a method to mark naturally breeding mosquitoes with stable isotopes. Culexpipiens f. molestus mosquitoes we...

  19. DsRed2 transient expression in Culex quinquefasciatus mosquitoes

    Scientific Electronic Library Online (English)

    Andre Barretto Bruno, Wilke; Sarah, Scaife; Luke, Alphey; Mauro Toledo, Marrelli.

    2013-06-01

    Full Text Available Culex quinquefasciatus mosquitoes have been successfully genetically modified only once, despite the efforts of several laboratories to transform and establish a stable strain. We have developed a transient gene expression method, in Culex, that delivers plasmid DNA directly to the mosquito haemoly [...] mph and additional tissues. We were able to express DsRed2 fluorescent protein in adult Cx. quinquefasciatus mosquitoes by injecting plasmids directly into their thorax. The expression of DsRed2 in adult Cx. quinquefasciatus mosquitoes is an important stepping stone to genetic transformation and the potential use of new control strategies and genetic interactions.

  20. Chikungunya virus and its mosquito vectors.

    Science.gov (United States)

    Higgs, Stephen; Vanlandingham, Dana

    2015-04-01

    Chikungunya virus (CHIKV), a mosquito-borne alphavirus of increasing public health significance, has caused large epidemics in Africa and the Indian Ocean basin; now it is spreading throughout the Americas. The primary vectors of CHIKV are Aedes (Ae.) aegypti and, after the introduction of a mutation in the E1 envelope protein gene, the highly anthropophilic and geographically widespread Ae. albopictus mosquito. We review here research efforts to characterize the viral genetic basis of mosquito-vector interactions, the use of RNA interference and other strategies for the control of CHIKV in mosquitoes, and the potentiation of CHIKV infection by mosquito saliva. Over the past decade, CHIKV has emerged on a truly global scale. Since 2013, CHIKV transmission has been reported throughout the Caribbean region, in North America, and in Central and South American countries, including Brazil, Columbia, Costa Rica, El Salvador, French Guiana, Guatemala, Guyana, Nicaragua, Panama, Suriname, and Venezuela. Closing the gaps in our knowledge of driving factors behind the rapid geographic expansion of CHIKV should be considered a research priority. The abundance of multiple primate species in many of these countries, together with species of mosquito that have never been exposed to CHIKV, may provide opportunities for this highly adaptable virus to establish sylvatic cycles that to date have not been seen outside of Africa. The short-term and long-term ecological consequences of such transmission cycles, including the impact on wildlife and people living in these areas, are completely unknown. PMID:25674945

  1. Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

    Science.gov (United States)

    Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...

  2. Satellite Microwave Remote Sensing for Environmental Modeling of Mosquito Population Dynamics

    OpenAIRE

    Chuang, Ting-wu; Henebry, Geoffrey M.; Kimball, John S.; Vanroekel-patton, Denise L.; Hildreth, Michael B.; Wimberly, Michael C.

    2012-01-01

    Environmental variability has important influences on mosquito life cycles and understanding the spatial and temporal patterns of mosquito populations is critical for mosquito control and vector-borne disease prevention. Meteorological data used for model-based predictions of mosquito abundance and life cycle dynamics are typically acquired from ground-based weather stations; however, data availability and completeness are often limited by sparse networks and resource availability. In contras...

  3. Usage and Perceived Side Effects of Personal Protective Measures against Mosquitoes among Current Users in Delhi

    OpenAIRE

    Charu Kohli; Rajesh Kumar; G. S. Meena; Singh, M.M.; Jyotiranjan Sahoo; G. K. Ingle

    2014-01-01

    Background. Mosquito-borne diseases constitute an important cause of morbidity and mortality. The use of personal protective measures (PPM) like mats, bednets, screening, repellents, liquid vaporizers, mosquito coils, and so forth has been advocated as an effective tool in control of mosquito-borne diseases, but data about the safety profile of personal protective measures is still scarce. Objective. To study the usage and side effects of personal protective measures against mosquitoes among ...

  4. Transgenic malaria-resistant mosquitoes have a fitness advantage when feeding on Plasmodium-infected blood

    OpenAIRE

    Marrelli, Mauro T.; Li, Chaoyang; Rasgon, Jason L.; Jacobs-Lorena, Marcelo

    2007-01-01

    The introduction of genes that impair Plasmodium development into mosquito populations is a strategy being considered for malaria control. The effect of the transgene on mosquito fitness is a crucial parameter influencing the success of this approach. We have previously shown that anopheline mosquitoes expressing the SM1 peptide in the midgut lumen are impaired for transmission of Plasmodium berghei. Moreover, the transgenic mosquitoes had no noticeable fitness load compared with nontransgeni...

  5. Natural Plant Sugar Sources of Anopheles Mosquitoes Strongly Impact Malaria Transmission Potential

    OpenAIRE

    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 ...

  6. Mitochondrial NAD+-dependent malic enzyme from Anopheles stephensi: a possible novel target for malaria mosquito control

    Directory of Open Access Journals (Sweden)

    Pon Jennifer

    2011-10-01

    Full Text Available Abstract Background Anopheles stephensi mitochondrial malic enzyme (ME emerged as having a relevant role in the provision of pyruvate for the Krebs' cycle because inhibition of this enzyme results in the complete abrogation of oxygen uptake by mitochondria. Therefore, the identification of ME in mitochondria from immortalized A. stephensi (ASE cells and the investigation of the stereoselectivity of malate analogues are relevant in understanding the physiological role of ME in cells of this important malaria parasite vector and its potential as a possible novel target for insecticide development. Methods To characterize the mitochondrial ME from immortalized ASE cells (Mos. 43; ASE, mass spectrometry analyses of trypsin fragments of ME, genomic sequence analysis and biochemical assays were performed to identify the enzyme and evaluate its activity in terms of cofactor dependency and inhibitor preference. Results The encoding gene sequence and primary sequences of several peptides from mitochondrial ME were found to be highly homologous to the mitochondrial ME from Anopheles gambiae (98% and 59% homologous to the mitochondrial NADP+-dependent ME isoform from Homo sapiens. Measurements of ME activity in mosquito mitochondria isolated from ASE cells showed that (i Vmax with NAD+ was 3-fold higher than that with NADP+, (ii addition of Mg2+ or Mn2+ increased the Vmax by 9- to 21-fold, with Mn2+ 2.3-fold more effective than Mg2+, (iii succinate and fumarate increased the activity by 2- and 5-fold, respectively, at sub-saturating concentrations of malate, (iv among the analogs of L-malate tested as inhibitors of the NAD+-dependent ME catalyzed reaction, small (2- to 3-carbons organic diacids carrying a 2-hydroxyl/keto group behaved as the most potent inhibitors of ME activity (e.g., oxaloacetate, tartronic acid and oxalate. Conclusions The biochemical characterization of Anopheles stephensi ME is of critical relevance given its important role in bioenergetics, suggesting that it is a suitable target for insecticide development.

  7. Study of mosquito attractants for photo catalytic mosquito trap

    OpenAIRE

    Dewi Tristantini; Slamet -; Angela Jessica Stephanie

    2014-01-01

    Photo catalytic mosquito trap is made of TiO2-Activated Carbon (AC) with a certain composition of AC. Research concerns on the heat spectrum which is produced by combination process of existing CO2 and humid air. The purpose of performance testing is to observe capability of this device in trapping mosquitoes related to the air temperature profile for heat spectrum is play important role for attracting mosquitoes. Result shows photo catalytic mosquito trap is more effective than devices which...

  8. Hey! A Mosquito Bit Me!

    Science.gov (United States)

    ... world. There are thousands of different kinds of mosquitoes in many different sizes and colors. The female ... a spine) to lay eggs and produce more mosquitoes. She has a special part of her mouth ...

  9. Attractive Toxic Sugar Baits: Control of Mosquitoes With the Low-Risk Active Ingredient Dinotefuran and Potential Impacts on Nontarget Organisms in Morocco

    OpenAIRE

    Khallaayoune, Khalid; Qualls, Whitney A.; Revay, Edita E.; Allan, Sandra A.; Arheart, Kristopher L; Kravchenko, Vasiliy D.; Xue, Rui-De; Schlein, Yosef; Beier, John C.; Müller, Günter C

    2013-01-01

    We evaluated the efficacy of attractive toxic sugar baits (ATSB) in the laboratory and field with the low-risk active ingredient dinotefuran against mosquito populations. Preliminary laboratory assays indicated that dinotefuran in solution with the sugar baits was ingested and resulted in high mortality of female Culex quinquefasciatus Say and Aedes aegypti Linnaeus. Field studies demonstrated >70% reduction of mosquito populations at 3 wk post-ATSB application. Nontarget feeding of seven ins...

  10. Median knock-down time as a new method for evaluating insecticide-treated textiles for mosquito control

    Directory of Open Access Journals (Sweden)

    Pigeon Olivier

    2008-06-01

    Full Text Available Abstract Background Insecticide treated bed nets are major tools for the Roll Back Malaria campaign. There are two types of Long-Lasting Insecticide-treated Nets (LNs on the market: coated nets and insecticide-incorporated nets. Nets provided to this market need a recommendation from the World Health Organization to be purchased by donors and NGOs. During laboratory study (phase I, the first step consists in evaluating the wash resistance of a new LN product. When insecticide-incorporated nets are washed, it takes time to regenerate the insecticidal activity, i.e. insecticide must migrate to the net surface to be accessible to mosquitoes. The interval of time required for regeneration must be carefully determined to ensure the accuracy of further results. WHOPES procedures currently recommend the determination of the regeneration time by using mortality data. However, as mortality cannot exceed 100%, a LN that regenerates a surface concentration exceeding the dosage for 100% mortality, will have its regeneration time underestimated. Methods The Median Knock Down Time (MKDT was determined as function of insecticide dosage on an inert surface, glass, and on polyester nettings using an acetone solution or a simple emulsion. Dosage response was also established for mortality data. The same method was then applied to a commercially polyethylene netting, currently under WHOPES evaluation, to determine the dynamics of regeneration as function of repeated washings. The deltamethrin content of these nets was estimated by Capillary Gas Chromatography (GC-ECD. Results MKDT was a linear function of log insecticide dosage on glass as on nettings. Mortality data were either 0 or 100% for most concentrations except for a narrow range. MKDT was log linear function of total deltamethrin content in a commercial polyethylene net exposed to washings. The regeneration time of this net increased with the number of washes and MKDT became higher. A new, easy and rapid method to determine MKDT is suggested. Discussion The MKDT is linearly correlated to log dosage on a given substrate and shows no saturation as mortality data do. It is suited to determine regeneration time of a product that is exposed to a stress, like washing or heating, where the process impacts on the bio-availability of the insecticide. Mortality data are useful for measuring product efficacy, whereas MKDT are better to measure dynamics of surface concentration like regeneration after a stressing process. Change in MKDT can be used to illustrate the loss of insecticide due to washing, but the slope of the curve is product and surface-dependent.

  11. Flavivirus-Mosquito Interactions

    Directory of Open Access Journals (Sweden)

    Yan-Jang S. Huang

    2014-11-01

    Full Text Available The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1–4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

  12. Study of mosquito attractants for photo catalytic mosquito trap

    Directory of Open Access Journals (Sweden)

    Dewi Tristantini

    2014-01-01

    Full Text Available Photo catalytic mosquito trap is made of TiO2-Activated Carbon (AC with a certain composition of AC. Research concerns on the heat spectrum which is produced by combination process of existing CO2 and humid air. The purpose of performance testing is to observe capability of this device in trapping mosquitoes related to the air temperature profile for heat spectrum is play important role for attracting mosquitoes. Result shows photo catalytic mosquito trap is more effective than devices which only consist of UV light or stream of CO2 and the humid air. A number of mosquitoes trapped by the photo catalyst coated panel configuration and UV lamps were lit proved far more effective because the heat production from recombination process. A little difference in temperature can be detected by mosquito.   Keywords: Photo Catalytic, Mosquito, Recombination.

  13. Radiation biology of mosquitoes

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2009-11-01

    Full Text Available Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi- field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

  14. MosquitoMap and the Mal-area calculator: new web tools to relate mosquito species distribution with vector borne disease

    Directory of Open Access Journals (Sweden)

    Christensen Jamie

    2010-02-01

    Full Text Available Abstract Background Mosquitoes are important vectors of diseases but, in spite of various mosquito faunistic surveys globally, there is a need for a spatial online database of mosquito collection data and distribution summaries. Such a resource could provide entomologists with the results of previous mosquito surveys, and vector disease control workers, preventative medicine practitioners, and health planners with information relating mosquito distribution to vector-borne disease risk. Results A web application called MosquitoMap was constructed comprising mosquito collection point data stored in an ArcGIS 9.3 Server/SQL geodatabase that includes administrative area and vector species x country lookup tables. In addition to the layer containing mosquito collection points, other map layers were made available including environmental, and vector and pathogen/disease distribution layers. An application within MosquitoMap called the Mal-area calculator (MAC was constructed to quantify the area of overlap, for any area of interest, of vector, human, and disease distribution models. Data standards for mosquito records were developed for MosquitoMap. Conclusion MosquitoMap is a public domain web resource that maps and compares georeferenced mosquito collection points to other spatial information, in a geographical information system setting. The MAC quantifies the Mal-area, i.e. the area where it is theoretically possible for vector-borne disease transmission to occur, thus providing a useful decision tool where other disease information is limited. The Mal-area approach emphasizes the independent but cumulative contribution to disease risk of the vector species predicted present. MosquitoMap adds value to, and makes accessible, the results of past collecting efforts, as well as providing a template for other arthropod spatial databases.

  15. Fungal infection counters insecticide resistance in African malaria mosquitoes

    OpenAIRE

    Farenhorst, M.; J. C. Mouatcho; Kikankie, C.K.; Brooke, B.D.; Hunt, R.H.; M. B. Thomas; Koekemoer, L. L.; Knols, B G J; M. Coetzee

    2009-01-01

    The evolution of insecticide resistance in mosquitoes is threatening the effectiveness and sustainability of malaria control programs in various parts of the world. Through their unique mode of action, entomopathogenic fungi provide promising alternatives to chemical control. However, potential interactions between fungal infection and insecticide resistance, such as cross-resistance, have not been investigated. We show that insecticide-resistant Anopheles mosquitoes remain susceptible to inf...

  16. Pesticides and public health: integrated methods of mosquito management.

    OpenAIRE

    Rose, R. I.

    2001-01-01

    Pesticides have a role in public health as part of sustainable integrated mosquito management. Other components of such management include surveillance, source reduction or prevention, biological control, repellents, traps, and pesticide-resistance management. We assess the future use of mosquito control pesticides in view of niche markets, incentives for new product development, Environmental Protection Agency registration, the Food Quality Protection Act, and improved pest management strate...

  17. UV light and urban pollution: Bad cocktail for mosquitoes?

    International Nuclear Information System (INIS)

    Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species–ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis–Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field

  18. UV light and urban pollution: Bad cocktail for mosquitoes?

    Energy Technology Data Exchange (ETDEWEB)

    Tetreau, Guillaume, E-mail: guillaume.tetreau@gmail.com [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France); Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456 (United States); Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud’homme, Sophie M.; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France)

    2014-01-15

    Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species–ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis–Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field.

  19. Remove Mosquito Habitats

    Science.gov (United States)

    ... monitor standing water sources. Get rid of standing water in rain gutters, old tires, buckets, plastic covers, toys or ... where mosquitoes can breed. Empty and change the water in bird baths, fountains, wading pools, rain barrels and potted plant trays at least once ...

  20. Identification of mosquito repellent odours from Ocimum forskolei

    Directory of Open Access Journals (Sweden)

    Glinwood Robert

    2011-09-01

    Full Text Available Abstract Background Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD with headspace extracts of crushed plants. Results EAD active compounds included (R-(--linalool, (S-(+-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R-(--?-copaene, methyl cinnamate and (E-ocimene. Of these compounds (R-(--linalool, methyl cinnamate and methyl salicylate reduced landing of female Aedes aegypti on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds. Conclusions The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics, and can be a locally sustainable part in mosquito control efforts.

  1. Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae

    Directory of Open Access Journals (Sweden)

    Banerjee Siddhartha S

    2008-10-01

    Full Text Available Abstract Background Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of Acilius sulcatus Linnaeus 1758 (Coleoptera: Dytiscidae as predator of mosquito immatures was made in the laboratory. Its efficacy under field condition was also determined to emphasize its potential as bio-control agent of mosquitoes. Methods In the laboratory, the predation potential of the larvae of A. sulcatus was assessed using the larvae of Culex quinquefasciatus Say 1823 (Diptera: Culicidae as prey at varying predator and prey densities and available space. Under field conditions, the effectiveness of the larvae of A. sulcatus was evaluated through augmentative release in ten cemented tanks hosting immatures of different mosquito species at varying density. The dip density changes in the mosquito immatures were used as indicator for the effectiveness of A. sulcatus larvae. Results A single larva of A. sulcatus consumed on an average 34 IV instar larvae of Cx. quinquefasciatus in a 24 h period. It was observed that feeding rate of A. sulcatus did not differ between the light-on (6 a.m. – 6 p.m., and dark (6 p.m. – 6 a.m. phases, but decreased with the volume of water i.e., space availability. The prey consumption of the larvae of A. sulcatus differed significantly (P A. sulcatus larvae, while with the withdrawal, a significant increase (p A. sulcatus in regulating mosquito immatures. In the control tanks, mean larval density did not differ (p > 0.05 throughout the study period. Conclusion the larvae of the dytiscid beetle A. sulcatus proved to be an efficient predator of mosquito immatures and may be useful in biocontrol of medically important mosquitoes.

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

    Science.gov (United States)

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

  3. Potential Use of Mosquito’s Salivary Components as Novel Target for The Development of Transmission Blocking Vaccine (TBV

    Directory of Open Access Journals (Sweden)

    KARTIKA SENJARINI

    2013-11-01

    Full Text Available Mosquito-borne diseases are rampant in most tropical regions of the world, especially rural, forested, and coastal areas such as Indonesia. Despite long-standing chemotherapeutic intercession and vector control programs, mosquito-borne diseases exact a heavy burden on human health in Indonesia. Two major public health problems transmitted by mosquito in Indonesia are malaria and dengue haemorrhagic fever (DHF, causing millions of clinical episodes occurring annually. Malaria is now recognized as a serious re-emerging threat to public health. DHF cases were first observed in 1968; since then, the incidence has been constantly increasing and the disease is now one of the principal causes of child lethality. It has been widely observed that saliva of mosquito that transmits the diseases contains several factors that could enhance pathogen infection. Therefore, it should be possible to control pathogen transmission by vaccinating the host against the molecule(s in saliva that potentiate the infection. However, specific component as a potential target for TBV in mosquito vectors of malaria & dengue, i.e. Anopheles and Aedes aegypti, has not been identified so far. This paper wanted to elaborate the potential role of salivary component from mosquitoes, particularly from Indonesian vectors as molecular target for developing TBV against two major Mosquito borne-diseases in Indonesia i.e. malaria and DHF.

  4. El control de los zancudos en Panamá: los entomólogos y el cambio ambiental durante la construcción del Canal / "Mosquito control in Panama : Entomologists and Environmental Change during the Construction of the Panama Canal

    Scientific Electronic Library Online (English)

    Paul, Sutter.

    2005-12-01

    Full Text Available Este ensayo examina los esfuerzos realizados por los Estados Unidos durante la construcción del Canal de Panamá para controlar los zancudos que sirven como vectores de la malaria y la fiebre amarilla. Antes de que se descubriera el papel de los zancudos en la transmisión de estas enfermedades, solía [...] asumirse que éstas eran parte integral de la naturaleza tropical. Sin embargo, los empleados estadounidenses que viajaron a Panamá en 1904 para construir el canal, no sólo llegaron con sus propias ideas sobre el trópico, sino con conocimiento de la teoría de los vectores y, por lo tanto, con nuevas herramientas para luchar contra las fiebres tropicales. El resultado fue un esfuerzo de saneamiento, liderado por William Gorgas y apoyado por una comunidad creciente de empleados de sanidad y entomólogos, que acabó con la fiebre amarilla en la zona del canal y redujo la incidencia de la malaria. Tal éxito sirvió para argumentar que estos esfuerzos sanitarios constituían una lección objetiva sobre cómo conquistar los trópicos. Pero una mirada más cuidadosa al control de zancudos en Panamá revela una historia diferente. Los empleados de sanidad y los entomólogos se dieron cuenta que el control de zancudos generalmente incluía atacar criaderos creados por los cambios ambientales y sociales creados por la construcción del canal. Así, los entomólogos ocupaban un lugar particular, pues apoyaron los objetivos imperialistas de los Estados Unidos en Panamá, pero, al establecer nexos entre las enfermedades y el cambio ambiental, subvirtieron el discurso oficial sobre los trópicos. Abstract in english This essay examines U.S. efforts to control the mosquito vectors of malaria and yellow fever during the construction of the Panama Canal . Before the discovery that mosquitoes transmitted malaria and yellow fever, most observers assumed these diseases were an entrenched part of tropical nature. But [...] when the United States entered Panama in 1904 to begin their turn at canal building, they came not only with their own ideas about the tropics, but also as beneficiaries of the vector discoveries and thus with new tools for fighting tropical fevers. The result was a sanitary effort, led by William Gorgas and supported by a growing community of sanitarians and entomologists, which rid the canal zone of yellow fever and reduced the incidence of malaria. American officials and observers claimed that their sanitary efforts provided an object lesson in how to conquer the tropics. But a closer look at mosquito controlin Panama reveals a different story. Sanitarians and entomologists noted that mosquito control usually involved attacking breeding grounds created by the environmental and social changes that came with U.S. canal building. By pointing out these relationships between disease and environmental change, entomologists occupied an intriguing space, at once supportive of U.S. imperial goals in Panama and subversive of the official discourse on tropicality.

  5. Towards the genetic manipulation of mosquito disease vectors

    International Nuclear Information System (INIS)

    Our research is aimed at developing the technologies necessary to undertake the genetic manipulation of insect vector genomes. In the longer term, we wish to explore the potential that this technology may have for developing novel strategies for the control of vector-borne diseases. The focus of our current research has been to: i) identify and characterise endogenous transposable elements in the genomes of mosquito vectors -research has focussed on identifying both Class I and Class 11 elements and determining their structure and distribution within mosquito genomes; ii) develop and use transfection systems for mosquito cells in culture as a test bed for transformation vectors and promoters - transfection techniques, vector constructs and different promoters driving reporter genes have been utilised to optimise the transformation of both Aedes aegypti and Anopheles gambiae cells in culture; iii) identify putative promoter sequences which are induced in the female mosquito midgut when it takes a blood meal - the Anopheles gambiae trypsin gene locus has been cloned and sequenced and the intergenic regions assessed for their ability to induce reporter gene expression in mosquito gut cells. The progress we have made in each of these areas will be described and discussed in the context of our longer term aim which is to introduce genes coding for antiparasitic agents into mosquito genomes in such a way that they are expressed in the mosquito midgut and disrupt transmission of the malaria parasite. (author)

  6. Toxicity of a plant based mosquito repellent/killer

    OpenAIRE

    Singh, Bhoopendra; Singh, Prakash Raj; Mohanty, Manoj Kumar

    2012-01-01

    The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant base...

  7. Energy Metabolism During Diapause in Culex pipiens Mosquitoes

    OpenAIRE

    Zhou, Guoli; Miesfeld, Roger L

    2008-01-01

    Diapause in overwintering adult female Culex pipiens mosquitoes plays an important role in the transmission of West Nile and other encephalitis-inducing flaviviruses. To investigate the dynamic metabolic processes that control Cx. pipiens diapause, we used radioactive tracer techniques with [14C]-glucose to investigate the metabolic fate and flux of glucose in adult mosquitoes reared under diapause (18°C, short day) and nondiapause (27°C, long day) conditions. We found that by 72 hours post...

  8. Effects of a botanical larvicide derived from Azadirachta indica (the neem tree) on oviposition behaviour in Anopheles gambiae s.s. mosquitoes

    OpenAIRE

    Howard, A.F.V.; Adongo, E.A.; Vulule, J; Githure, J.

    2011-01-01

    More focus is given to mosquito larval control due to the necessity to use several control techniques together in integrated vector management programmes. Botanical products are thought to be able to provide effective, sustainable and cheap mosquito larval control tools. However, bio-larvicides like Azadirachta indica (neem) could repel adult mosquitoes from laying their eggs in the treated larval habitats. In this study the response of Anopheles gambiae s.s. mosquitoes towards varying doses ...

  9. Attractive toxic sugar baits: Control of mosquitoes with the low risk active ingredient dinotefuran and potential impacts on non-target organisms in Morocco

    Science.gov (United States)

    We evaluated the efficacy of ATSB in the laboratory and the field with the low risk active ingredient dinotefuran against mosquito populations. Assays indicated that dinotefuran in solution with the sugar baits was ingested and resulted in high mortality of female Culex quinquefasciatus and Aedes a...

  10. UV light and urban pollution: bad cocktail for mosquitoes?

    Science.gov (United States)

    Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane

    2014-01-01

    Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species-ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis-Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field. PMID:24275062

  11. Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae) from an egyptian locality / Potencial de óleos de plantas biologicamente ativos para o controle da larva do mosquito Culex pipiens (Diptera: Culicidae) de localidade egípcia

    Scientific Electronic Library Online (English)

    Hanem Fathy, Khater; Afaf Abdel-Salam, Shalaby.

    2008-04-01

    Full Text Available O efeito inseticida de seis óleos de plantas comercialmente disponíveis foi testado contra larvas de 4ºinstar de Culex pipiens. Larvas foram coletadas originalmente de Meit El-Attar, Qalyubia Governorate, Egito e então cultivadas no laboratório até a geração F1. Os valores LC50 foram 32,42, 47,17, 7 [...] 1,37, 83,36, 86,06 e 152,94 ppm para o feno grego (Trigonella foenum-grecum), amêndoa da terra (Cyperus esculentus), mostarda (Brassica compestris), olíbano (Boswellia serrata), rocket (Eruca sativa) e salsa (Carum ptroselium), respectivamente. Os óleos testados alteraram alguns aspectos biológicos do C. pipiens, por exemplo os períodos de desenvolvimento, estados de crisálida, e emergências de adultos. As concentrações mais baixas de óleo de olíbano e feno grego causaram extraordinário prolongamento da duração larval e pupal. Dados também mostraram que o aumento das concentrações foi diretamente proporcional à redução no estado de crisálida e emergências dos adultos. Notável decréscimo no estado de crisálida foi conseguido com o óleo de mostarda a 1000 ppm. Emergência de adulto foi diminuída no óleo de amêndoa da terra e feno grego a 25 ppm. Além do mais, os óleos de plantas testados, exibiram várias anormalidades morfológicas nas larvas, pupas e estádios adultos. Consequentemente, o óleo de feno grego foi o óleo mais potente e o maior causador de malformação em ambos estádios larval e pupal. Potencial dos óleos de plantas aplicados mostraram excelente resultado no controle do C. pipiens. Abstract in english The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, [...] 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.

  12. Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae from an egyptian locality Potencial de óleos de plantas biologicamente ativos para o controle da larva do mosquito Culex pipiens (Diptera: Culicidae de localidade egípcia

    Directory of Open Access Journals (Sweden)

    Hanem Fathy Khater

    2008-04-01

    Full Text Available The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum, earth almond (Cyperus esculentus, mustard (Brassica compestris, olibanum (Boswellia serrata, rocket (Eruca sativa, and parsley (Carum ptroselinum, respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.O efeito inseticida de seis óleos de plantas comercialmente disponíveis foi testado contra larvas de 4ºinstar de Culex pipiens. Larvas foram coletadas originalmente de Meit El-Attar, Qalyubia Governorate, Egito e então cultivadas no laboratório até a geração F1. Os valores LC50 foram 32,42, 47,17, 71,37, 83,36, 86,06 e 152,94 ppm para o feno grego (Trigonella foenum-grecum, amêndoa da terra (Cyperus esculentus, mostarda (Brassica compestris, olíbano (Boswellia serrata, rocket (Eruca sativa e salsa (Carum ptroselium, respectivamente. Os óleos testados alteraram alguns aspectos biológicos do C. pipiens, por exemplo os períodos de desenvolvimento, estados de crisálida, e emergências de adultos. As concentrações mais baixas de óleo de olíbano e feno grego causaram extraordinário prolongamento da duração larval e pupal. Dados também mostraram que o aumento das concentrações foi diretamente proporcional à redução no estado de crisálida e emergências dos adultos. Notável decréscimo no estado de crisálida foi conseguido com o óleo de mostarda a 1000 ppm. Emergência de adulto foi diminuída no óleo de amêndoa da terra e feno grego a 25 ppm. Além do mais, os óleos de plantas testados, exibiram várias anormalidades morfológicas nas larvas, pupas e estádios adultos. Consequentemente, o óleo de feno grego foi o óleo mais potente e o maior causador de malformação em ambos estádios larval e pupal. Potencial dos óleos de plantas aplicados mostraram excelente resultado no controle do C. pipiens.

  13. A Visit to Florida's Mosquito Man

    Science.gov (United States)

    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.

  14. Arbovirus models to provide practical management tools for mosquito control and disease prevention in the Northern Territory, Australia.

    Science.gov (United States)

    Jacups, Susan P; Whelan, Peter I; Harley, David

    2011-03-01

    Ross River virus (RRV) causes the most common human arbovirus disease in Australia. Although the disease is nonfatal, the associated arthritis and postinfection fatigue can be debilitating for many months, impacting on workforce participation. We sought to create an early-warning system to notify of approaching RRV disease outbreak conditions for major townships in the Northern Territory. By applying a logistic regression model to meteorologic factors, including rainfall, a postestimation analysis of sensitivity and specificity can create rainfall cut-points. These rainfall cut-points indicate the rainfall level above which previous epidemic conditions have occurred. Furthermore, rainfall cut-points indirectly adjust for vertebrate host data from the agile wallaby (Macropus agilis) as the life cycle of the agile wallaby is intricately meshed with the wet season. Once generated, cut-points can thus be used prospectively to allow timely implementation of larval survey and control measures and public health warnings to preemptively reduce RRV disease incidence. Cut-points are location specific and have the capacity to replace previously used models, which require data management and input, and rarely provide timely notification for vector control requirements and public health warnings. These methods can be adapted for use elsewhere. PMID:21485389

  15. Avaliação de estirpes e de uma nova formulação granulada de Bacillus sphaericus Neide para o controle de mosquitos / Evaluation of isolates and a new granular formulation of Bacillus sphaericus Neide for control of mosquitoes

    Scientific Electronic Library Online (English)

    Luis F.A., Alves; Sérgio B., Alves; José, Lopes; Rogério B., Lopes.

    2006-08-01

    Full Text Available Foram estudadas 19 estirpes de Bacillus sphaericus Neide obtidos no Brasil além de uma estirpe considerada padrão (2362) fornecida pelo Instituto Pasteur. A maioria das estirpes foi mais eficiente que o padrão, sendo que sete deles causaram mortalidade igual ou superior a 80%, em baixa concentração [...] (7 × 10² esporos/ml). A estirpe ESALQ MS6 foi selecionada para formulação por apresentar melhor produção, em meio de cultura líquido (3 × 10(9) UFC/ml). A formulação granulada G4 foi testada em criadouros artificiais, constituídos de baldes plásticos com 10 L de água e 20 larvas de 3º ínstar de Culex quinquefasciatus Say (Diptera: Culicidae). Comparou-se a eficiência da formulação em teste, em três concentrações diferentes, com um produto comercial. As avaliações foram feitas 24 horas, sete e 18 dias após a inoculação, seguindo-se a reposição de larvas no balde. A formulação G4 foi semelhante ao produto comercial, controlando 100% das larvas nas concentrações testadas, contudo teve maior tempo de permanência dos grânulos na superfície. Em lagoas de tratamento de efluentes de cortume, a formulação G4, na concentração de 2 kg/ha reduziu o número de larvas em 21%, 47%, 85% e 94%, após 1, 3, 7 e 15 dias, respectivamente. Abstract in english Nineteen Bacillus sphaericus Neide strains obtained in Brazil were evaluated in addition to a standard strain (2362) supplied by Pasteur Institute. Most strains were more efficient than the standard, and seven of them caused mortality equal to or higher than 80%, at a low concentration (7 × 10² spor [...] es/ml). Strain ESALQ MS6 was selected for formulation, since it showed better yield in liquid culture medium (3 × 10(9) CFU/ml). The G4 granular formulation was tested in artificial rearing sites, consisting of plastic buckets containing 10 L water and twenty 3rd-instar larvae of Culex quinquefasciatus Say (Diptera: Culicidae). The efficiency of formulation was compared against a commercial product, at three different concentrations. Evaluations were taken every 24h, at seven and 18 days after inoculation, with subsequent replacement of larvae in the bucket. The G4 formulation was similar to the commercial product, and controlled 100% of the larvae at the concentrations tested; however, the granules remained at the surface for a longer period. In tannery effluent treatment ponds, the G4 formulation at a concentration of 2 kg/ha reduced the number of larvae by 21%, 47%, 85%, and 94%, after 1, 3, 7, and 15 days, respectively.

  16. Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae) from an Egyptian locality.

    Science.gov (United States)

    Khater, Hanem Fathy; Shalaby, Afaf Abdel-Salam

    2008-01-01

    The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens. PMID:18488090

  17. Identification of mosquito repellent odours from Ocimum forskolei

    OpenAIRE

    Glinwood Robert; Ghebru Maedot; Ignell Rickard; Dekker Teun; Hopkins Richard

    2011-01-01

    Abstract Background Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants. Results EAD active compounds inclu...

  18. THE LARVICIDAL ACTIVITY OF INDIGOFERA ARRECTA LEAF EXTRACT AGAINST CULEX MOSQUITO LARVAE

    Directory of Open Access Journals (Sweden)

    Raheli Neema M, Ojunga M and Ramesh F*

    2014-12-01

    Full Text Available The present study was done to assess the larvicidal activity of the Java indigo plant against the larvae of culex mosquito. The plant leaves were extracted using methanol and water (9:1. After extraction a bioassay was conducted to test its activity in the larva of culex mosquito. The mortality data was subjected to probit analysis to determine the lethal concentration. The Java indigo leaf extract can be used as a natural insecticide control against the Culex mosquito larvae.

  19. Insecticide-Treated Nets Can Reduce Malaria Transmission by Mosquitoes Which Feed Outdoors

    OpenAIRE

    Govella, Nicodem J; Okumu, Fredros O.; Killeen, Gerry F.

    2010-01-01

    Insecticide treated nets (ITNs) represent a powerful means for controlling malaria in Africa because the mosquito vectors feed primarily indoors at night. The proportion of human exposure that occurs indoors, when people are asleep and can conveniently use ITNs, is therefore very high. Recent evidence suggests behavioral changes by malaria mosquito populations to avoid contact with ITNs by feeding outdoors in the early evening. We adapt an established mathematical model of mosquito behavior a...

  20. Wolbachia Enhances West Nile Virus (WNV) Infection in the Mosquito Culex tarsalis

    OpenAIRE

    Dodson, Brittany L.; Grant L. Hughes; Paul, Oluwatobi; Matacchiero, Amy C; Kramer, Laura D; Rasgon, Jason L

    2014-01-01

    Novel strategies are required to control mosquitoes and the pathogens they transmit. One attractive approach involves maternally inherited endosymbiotic Wolbachia bacteria. After artificial infection with Wolbachia, many mosquitoes become refractory to infection and transmission of diverse pathogens. We evaluated the effects of Wolbachia (wAlbB strain) on infection, dissemination and transmission of West Nile virus (WNV) in the naturally uninfected mosquito Culex tarsalis, which is an importa...

  1. Limited Dengue Virus Replication in Field-Collected Aedes aegypti Mosquitoes Infected with Wolbachia

    OpenAIRE

    Frentiu, Francesca D.; Zakir, Tasnim; Walker, Thomas; Popovici, Jean; Pyke, Alyssa T.; van den Hurk, Andrew; McGraw, Elizabeth A; O'Neill, Scott L

    2014-01-01

    Almost half of the world's population is at risk of contracting dengue virus, particularly in the tropics and sub-tropics. The virus is transmitted by the mosquito Aedes aegypti, a cosmopolitan species that has proved difficult to control using traditional methods. A new biocontrol strategy has been developed involving the release of mosquitoes infected with Wolbachia bacteria. Mosquitoes with the wMel strain of Wolbachia show dramatically reduced replication and transmission of dengue virus ...

  2. Predictors of mosquito net use in Ghana

    Directory of Open Access Journals (Sweden)

    Baume Carol A

    2011-09-01

    Full Text Available Abstract Background During the past decade the malaria control community has been successful in dramatically increasing the number of households that own mosquito nets. However, as many as half of nets already in households go unused. This study examines the factors associated with use of nets owned in Ghana. Methods The data come from an August 2008 survey in Ghana of households with a pregnant woman or a guardian of a child under five, conducted during the rainy season. 1796 households were included in this analysis, which generated a sample of 1,852 mosquito nets. Using each net owned as the unit of analysis, multivariate logistic regression was used to examine the relationship of net used last night with 23 potentially explanatory variables having to do with characteristics of the household, of the respondent, and of the net. Odds Ratios, p-values, and confidence intervals were calculated for each variable to develop an explanatory model. Results The final multivariate model consisted of 10 variables statistically associated with whether or not the net was used the prior night: rural location, lower SES, not using coils for mosquito control, fewer nets in the household, newer nets and those in better condition, light blue colour, higher level of education of the guardian of the child under five, knowing that mosquitoes transmit malaria, and paying for the net instead of obtaining it free of charge. Conclusions The results of this study suggest that net use would increase in Ghana if coloured nets were made available in mass distributions as well as in the commercial market; if programmes emphasize that malaria is caused only by night-biting mosquitoes, and that nets protect against mosquitoes better than coils and need to be used even if coils are burning; if donated nets are replaced more frequently so that households have nets that are in good condition; and if there were support for the commercial market so that those who can afford to purchase a net and want to choose their own nets can do so.

  3. Effectiveness of an integrated vector management control strategy for the tiger mosquito (Aedes albopictus) a case study in Sant Cugat del Vallès (Barcelona) /

    OpenAIRE

    Abramides, Gisela Chebabi

    2013-01-01

    El mosquito tigre, Aedes albopictus (Skuse, 1894), es una especie invasora que actualmente se encuentra en los cinco continentes, extendiéndose desde su área nativa en el sudeste de Asia a través del comercio internacional de neumáticos usados y del bambú de la suerte. En Cataluña fue detectado por primera vez en el año 2004, en el municipio Sant Cugat del Vallès, y se expandió rápidamente en los últimos cinco años a más de 200 municipios de Cataluña y Alicante. Esta especie es ...

  4. The Role of Innate Immunity in Conditioning Mosquito Susceptibility to West Nile Virus

    Directory of Open Access Journals (Sweden)

    Abhishek N. Prasad

    2013-12-01

    Full Text Available Arthropod-borne viruses (arboviruses represent an emerging threat to human and livestock health globally. In particular, those transmitted by mosquitoes present the greatest challenges to disease control efforts. An understanding of the molecular basis for mosquito innate immunity to arbovirus infection is therefore critical to investigations regarding arbovirus evolution, virus-vector ecology, and mosquito vector competence. In this review, we discuss the current state of understanding regarding mosquito innate immunity to West Nile virus. We draw from the literature with respect to other virus-vector pairings to attempt to draw inferences to gaps in our knowledge about West Nile virus and relevant vectors.

  5. Mosquitoes: A Resource Book for the Classroom.

    Science.gov (United States)

    Gillmor, Mary S.; And Others

    This booklet was written for anyone interested in growing mosquitoes and experimenting with them. There are three major sections: (1) rationale for studying mosquitoes, (2) raising mosquitoes, and (3) some scientific findings. The first section describes basic information about mosquitoes. The second section includes information about materials,…

  6. Uso de mosquiteros y otros materiales impregnados con insecticida para el control de la malaria en las Américas Use of insecticide-impregnated mosquito nets and other impregnated materials for malaria control in the Americas

    Directory of Open Access Journals (Sweden)

    R. H. Zimmerman

    1997-01-01

    Full Text Available En el presente artículo se analiza el uso actual de mosquiteros y de otros materiales impregnados con insecticida en las Américas. Se examinan diversos estudios efectuados en Brasil, Colombia, Ecuador, Guatemala, Perú, Suriname y Venezuela y se llega a la conclusión de que, en su mayor parte, estos estudios adolecen de graves deficiencias de diseño experimental, problemas de excesiva brevedad, y medición inadecuada de indicadores de salud. En el análisis se resalta la gran dificultad de llevar a cabo estudios científicos que buscan determinar el efecto de los materiales tratados con insecticida en la incidencia de malaria. En particular, la baja incidencia de malaria en las Américas, la elevada prevalencia de Plasmodium vivax y de casos recurrentes, y la relación existente entre los patrones de actividad del ser humano y los hábitos de picadura crepusculares de ciertos vectores de la malaria impiden hacer experimentos de fácil diseño y ejecución. Por ahora sería prematuro usar mosquiteros u otros materiales impregnados con insecticida como componentes principales de un programa integral para el control de la malaria. No obstante, se recomienda que se considere la posibilidad de realizar ensayos e intervenciones bien diseñados a gran escala, siempre que se basen en un conocimiento profundo de la dinámica de la transmisión de la malaria en la zona en estudio.This article reviews the current status of insecticide-impregnated mosquito nets and other impregnated materials in the Americas. Studies from Brazil, Colombia, Ecuador, Guatemala, Peru, Suriname, and Venezuela are examined. It is concluded that most studies have suffered from experimental design errors, short duration problems, and/or inadequate measurement of health indicators. The review brings out the great difficulty of conducting scientific studies that attempt to measure the impact of insecticide-treated materials on malaria incidence. In particular, the low incidence of malaria in the Americas, the high prevalences of Plasmodium vivax and relapsing cases, and the relationship between human activity patterns and the crepuscular biting patterns of certain malaria vectors stand in the way of easy experimental design and execution. The utilization of impregnated mosquito nets or other impregnated materials as a major component of an integrated malaria control program would be premature at this time. However, it is recommended that well-conceived large-scale trials and interventions be considered when they are based on a thorough understanding of the dynamics of malaria transmission in the area of study.

  7. Uso de mosquiteros y otros materiales impregnados con insecticida para el control de la malaria en las Américas / Use of insecticide-impregnated mosquito nets and other impregnated materials for malaria control in the Americas

    Scientific Electronic Library Online (English)

    R. H., Zimmerman; J., Voorham.

    Full Text Available En el presente artículo se analiza el uso actual de mosquiteros y de otros materiales impregnados con insecticida en las Américas. Se examinan diversos estudios efectuados en Brasil, Colombia, Ecuador, Guatemala, Perú, Suriname y Venezuela y se llega a la conclusión de que, en su mayor parte, estos [...] estudios adolecen de graves deficiencias de diseño experimental, problemas de excesiva brevedad, y medición inadecuada de indicadores de salud. En el análisis se resalta la gran dificultad de llevar a cabo estudios científicos que buscan determinar el efecto de los materiales tratados con insecticida en la incidencia de malaria. En particular, la baja incidencia de malaria en las Américas, la elevada prevalencia de Plasmodium vivax y de casos recurrentes, y la relación existente entre los patrones de actividad del ser humano y los hábitos de picadura crepusculares de ciertos vectores de la malaria impiden hacer experimentos de fácil diseño y ejecución. Por ahora sería prematuro usar mosquiteros u otros materiales impregnados con insecticida como componentes principales de un programa integral para el control de la malaria. No obstante, se recomienda que se considere la posibilidad de realizar ensayos e intervenciones bien diseñados a gran escala, siempre que se basen en un conocimiento profundo de la dinámica de la transmisión de la malaria en la zona en estudio. Abstract in english This article reviews the current status of insecticide-impregnated mosquito nets and other impregnated materials in the Americas. Studies from Brazil, Colombia, Ecuador, Guatemala, Peru, Suriname, and Venezuela are examined. It is concluded that most studies have suffered from experimental design er [...] rors, short duration problems, and/or inadequate measurement of health indicators. The review brings out the great difficulty of conducting scientific studies that attempt to measure the impact of insecticide-treated materials on malaria incidence. In particular, the low incidence of malaria in the Americas, the high prevalences of Plasmodium vivax and relapsing cases, and the relationship between human activity patterns and the crepuscular biting patterns of certain malaria vectors stand in the way of easy experimental design and execution. The utilization of impregnated mosquito nets or other impregnated materials as a major component of an integrated malaria control program would be premature at this time. However, it is recommended that well-conceived large-scale trials and interventions be considered when they are based on a thorough understanding of the dynamics of malaria transmission in the area of study.

  8. Mosquito Management on National Wildlife Refuges, Ecosystem Effects Study. Phase II, Part 1 - Effects of Ultra Low Volume Applications of Pyrethrin, Malathion and Permethrin on Macro-Invertebrates in the Sacramento National Wildlife Refuge, California

    US Fish and Wildlife Service, Department of the Interior — Mosquito control districts often use ultralow volume ULV applications of insecticides to control adult mosquitoes. Few field studies have tested the effects of...

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

    Science.gov (United States)

    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...

  10. Don't Let the Bugs Bite: Preventing Dengue and Other Diseases Spread by Mosquitoes

    Centers for Disease Control (CDC) Podcasts

    2007-12-10

    This year (2007) CDC is receiving a great many reports of cases of Dengue fever, which is spread by mosquitoes. This podcast discusses ways travelers to the tropics can protect themselves from mosquito bites.  Created: 12/10/2007 by National Center for the Prevention, Detection and Control of Infectious Diseases (NCPDCID).   Date Released: 12/10/2007.

  11. Response of the mosquito protein interaction network to dengue infection

    Directory of Open Access Journals (Sweden)

    Pike Andrew D

    2010-06-01

    Full Text Available Abstract Background Two fifths of the world's population is at risk from dengue. The absence of effective drugs and vaccines leaves vector control as the primary intervention tool. Understanding dengue virus (DENV host interactions is essential for the development of novel control strategies. The availability of genome sequences for both human and mosquito host greatly facilitates genome-wide studies of DENV-host interactions. Results We developed the first draft of the mosquito protein interaction network using a computational approach. The weighted network includes 4,214 Aedes aegypti proteins with 10,209 interactions, among which 3,500 proteins are connected into an interconnected scale-free network. We demonstrated the application of this network for the further annotation of mosquito proteins and dissection of pathway crosstalk. Using three datasets based on physical interaction assays, genome-wide RNA interference (RNAi screens and microarray assays, we identified 714 putative DENV-associated mosquito proteins. An integrated analysis of these proteins in the network highlighted four regions consisting of highly interconnected proteins with closely related functions in each of replication/transcription/translation (RTT, immunity, transport and metabolism. Putative DENV-associated proteins were further selected for validation by RNAi-mediated gene silencing, and dengue viral titer in mosquito midguts was significantly reduced for five out of ten (50.0% randomly selected genes. Conclusions Our results indicate the presence of common host requirements for DENV in mosquitoes and humans. We discuss the significance of our findings for pharmacological intervention and genetic modification of mosquitoes for blocking dengue transmission.

  12. Nature, Nurture and Evolution of Intra-Species Variation in Mosquito Arbovirus Transmission Competence

    Directory of Open Access Journals (Sweden)

    Walter J. Tabachnick

    2013-01-01

    Full Text Available Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses. Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature and environmental (nurture factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that comprise mosquito competence. The complex interactions between environmental and genetic factors controlling these traits and the factors shaping variation in Nature are largely unknown. The norms of reaction of specific genes influencing competence, their distributions in natural populations and the effects of genetic polymorphism on phenotypic variation need to be determined. Mechanisms influencing competence are not likely due to natural selection because of the direct effects of the arbovirus on mosquito fitness. More likely the traits for mosquito competence for arboviruses are the effects of adaptations for other functions of these competence mechanisms. Determining these other functions is essential to understand the evolution and distributions of competence for arboviruses. This information is needed to assess risk from mosquito-borne disease, predict new mosquito-arbovirus systems, and provide novel strategies to mitigate mosquito-borne arbovirus transmission.

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

    OpenAIRE

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

    2010-01-01

    To overcome burden of mosquito-borne diseases, multiple control strategies are needed. Population replacement with genetically modified mosquitoes carrying antipathogen effector genes is one of the possible approaches for controlling disease transmission. However, transgenic mosquitoes with antipathogen phenotypes based on overexpression of a single type effector molecule are not efficient in interrupting pathogen transmission. Here, we show that co-overexpression of two antimicrobial peptide...

  14. Elizabethkingia anophelis: molecular manipulation and interactions with mosquito hosts.

    Science.gov (United States)

    Chen, Shicheng; Bagdasarian, Michael; Walker, Edward D

    2015-03-01

    Flavobacteria (members of the family Flavobacteriaceae) dominate the bacterial community in the Anopheles mosquito midgut. One such commensal, Elizabethkingia anophelis, is closely associated with Anopheles mosquitoes through transstadial persistence (i.e., from one life stage to the next); these and other properties favor its development for paratransgenic applications in control of malaria parasite transmission. However, the physiological requirements of E. anophelis have not been investigated, nor has its capacity to perpetuate despite digestion pressure in the gut been quantified. To this end, we first developed techniques for genetic manipulation of E. anophelis, including selectable markers, reporter systems (green fluorescent protein [GFP] and NanoLuc), and transposons that function in E. anophelis. A flavobacterial expression system based on the promoter PompA was integrated into the E. anophelis chromosome and showed strong promoter activity to drive GFP and NanoLuc reporter production. Introduced, GFP-tagged E. anophelis associated with mosquitoes at successive developmental stages and propagated in Anopheles gambiae and Anopheles stephensi but not in Aedes triseriatus mosquitoes. Feeding NanoLuc-tagged cells to A. gambiae and A. stephensi in the larval stage led to infection rates of 71% and 82%, respectively. In contrast, a very low infection rate (3%) was detected in Aedes triseriatus mosquitoes under the same conditions. Of the initial E. anophelis cells provided to larvae, 23%, 71%, and 85% were digested in A. stephensi, A. gambiae, and Aedes triseriatus, respectively, demonstrating that E. anophelis adapted to various mosquito midgut environments differently. Bacterial cell growth increased up to 3-fold when arginine was supplemented in the defined medium. Furthermore, the number of NanoLuc-tagged cells in A. stephensi significantly increased when arginine was added to a sugar diet, showing it to be an important amino acid for E. anophelis. Animal erythrocytes promoted E. anophelis growth in vivo and in vitro, indicating that this bacterium could obtain nutrients by participating in erythrocyte lysis in the mosquito midgut. PMID:25595771

  15. Señales físico químicas involucradas en la búsqueda de hospederos y en la inducción de picadura por mosquitos Physic-chemical signals involved in host localization and induction of disease vector mosquito bites

    Directory of Open Access Journals (Sweden)

    José Luis Torres-Estrada

    2003-12-01

    Full Text Available Las hembras de los mosquitos vectores de enfermedades utilizan señales físicas y químicas para localizar su fuente de alimentación sanguínea en hospederos vertebrados. Los mosquitos zoofílicos responden preferentemente al CO2 y al octenol liberados en la respiración y excreciones, mientras que los mosquitos antropofílicos responden al ácido láctico y a una variedad de compuestos del sudor. Estos compuestos son modificados por microrganismos saprófitos de las glándulas sebáceas de la piel. Otros factores presentes en las viviendas contribuyen a la integración de microsistemas constituidos por olores característicos, que explican los diferentes niveles de atracción de mosquitos y la focalización de la transmisión del paludismo a una porción de casas en localidades de áreas endémicas. La identificación de estos atrayentes químicos y sus moléculas receptoras en mosquitos puede ser utilizada como complemento de nuevos métodos para la vigilancia epidemiológica, para atraer a los mosquitos a trampas de colecta o para incrementar su contacto con insecticidas usados en su control, así como en la manipulación genética para desviar las picaduras de los mosquitos hacia otros hospederos vertebrados.Disease vector female mosquitoes respond to physic-chemical signals to localize vertebrate hosts for blood meals. Zoophylic mosquitoes preferentially respond to CO2 and octenol released in the breath and bodily fluids, while anthropophylic mosquitoes respond to lactic acid and a variety of sweat compounds. These compounds are modified by saprophytic microorganisms in the skin sebaceous glands. Other factors present in human dwellings contribute to the integration of microsystems with characteristic odors that have different attraction for mosquitoes, explaining the focalization of malaria transmission in few households in endemic areas. The identification of the chemical attractants and their molecular receptors could be used to complement new methods to attract mosquitoes to traps during epidemiological surveys, to increase their contact with insecticides in control interventions, and for genetic manipulation to divert mosquito bites towards other animal populations.

  16. Toxicity of a plant based mosquito repellent/killer

    Science.gov (United States)

    Singh, Prakash Raj; Mohanty, Manoj Kumar

    2012-01-01

    The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant based insect repellents/killers pertinent articles published in journals and authentic books were reviewed. The World Wide Web and the Extension Toxicity Network database (IPCS-ITOX) were also searched for toxicology data and other pertinent information. Repellents do not all share a single mode of action and surprisingly little is known about how repellents act on their target insects. Moreover, different mosquito species may react differently to the same repellent. After analysis of available data and information on the ingredient, of the product in relation to medicinal uses, acute and chronic toxicity of the selected medicinal plants, it can be concluded that the ingredients included in the herbal product can be used as active agents against mosquitoes. If the product which contains the powder of the above said plants is applied with care and safety, it is suitable fo use as a mosquito repellent/killer. PMID:23554562

  17. Global Cross-Talk of Genes of the Mosquito Aedes aegypti in Response to Dengue Virus Infection

    OpenAIRE

    Behura, Susanta K.; Gomez-machorro, Consuelo; Harker, Brent W.; Debruyn, Becky; Lovin, Diane D.; Hemme, Ryan R.; Mori, Akio; Romero-severson, Jeanne; Severson, David W.

    2011-01-01

    Dengue virus is primarily transmitted by Aedes aegypti mosquitoes. Control of the vector mosquito is the major practice to prevent dengue. However, it is not well known how the virus can infect some mosquito strains but fail to do so with other refractory strains. To address that question, we conducted whole genome microarray based gene expression studies between susceptible and refractory strains of A. aegypti to identify gene expression patterns following challenge with dengue virus. Our an...

  18. Activation of Akt Signaling Reduces the Prevalence and Intensity of Malaria Parasite Infection and Lifespan in Anopheles stephensi Mosquitoes

    OpenAIRE

    Corby-Harris, Vanessa; Drexler, Anna; Watkins de Jong, Laurel; Antonova, Yevgeniya; Pakpour, Nazzy; Ziegler, Rolf; Ramberg, Frank; Lewis, Edwin E.; Brown, Jessica M.; Luckhart, Shirley; Riehle, Michael A.

    2010-01-01

    Malaria (Plasmodium spp.) kills nearly one million people annually and this number will likely increase as drug and insecticide resistance reduces the effectiveness of current control strategies. The most important human malaria parasite, Plasmodium falciparum, undergoes a complex developmental cycle in the mosquito that takes approximately two weeks and begins with the invasion of the mosquito midgut. Here, we demonstrate that increased Akt signaling in the mosquito midgut disrupts parasite ...

  19. A male-determining factor in the mosquito Aedes aegypti.

    Science.gov (United States)

    Hall, Andrew Brantley; Basu, Sanjay; Jiang, Xiaofang; Qi, Yumin; Timoshevskiy, Vladimir A; Biedler, James K; Sharakhova, Maria V; Elahi, Rubayet; Anderson, Michelle A E; Chen, Xiao-Guang; Sharakhov, Igor V; Adelman, Zach N; Tu, Zhijian

    2015-06-12

    Sex determination in the mosquito Aedes aegypti is governed by a dominant male-determining factor (M factor) located within a Y chromosome-like region called the M locus. Here, we show that an M-locus gene, Nix, functions as an M factor in A. aegypti. Nix exhibits persistent M linkage and early embryonic expression, two characteristics required of an M factor. Nix knockout with clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 resulted in largely feminized genetic males and the production of female isoforms of two key regulators of sexual differentiation: doublesex and fruitless. Ectopic expression of Nix resulted in genetic females with nearly complete male genitalia. Thus, Nix is both required and sufficient to initiate male development. This study provides a foundation for mosquito control strategies that convert female mosquitoes into harmless males. PMID:25999371

  20. Statics and dynamics of malaria infection in Anopheles mosquitoes

    Directory of Open Access Journals (Sweden)

    Ellis McKenzie F

    2004-06-01

    Full Text Available Abstract The classic formulae in malaria epidemiology are reviewed that relate entomological parameters to malaria transmission, including mosquito survivorship and age-at-infection, the stability index (S, the human blood index (HBI, proportion of infected mosquitoes, the sporozoite rate, the entomological inoculation rate (EIR, vectorial capacity (C and the basic reproductive number (R0. The synthesis emphasizes the relationships among classic formulae and reformulates a simple dynamic model for the proportion of infected humans. The classic formulae are related to formulae from cyclical feeding models, and some inconsistencies are noted. The classic formulae are used to to illustrate how malaria control reduces malaria transmission and show that increased mosquito mortality has an effect even larger than was proposed by Macdonald in the 1950's.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Rina Marina

    2012-12-01

    Full Text Available Aedes aegypti and Ae. albopictus mosquitoes being the vector of Dengue Haemorrhagic Fever (DHF. Various effort have been done to control the mosquitoes, including using plant extract as repellent. Pandanus amaryllifolius and Notophanax scutellarium leaf were known to posses repellent activity for mosquito species. The study aimed to examine efJectiveness of P. amaryllifolius and N. scutellarium leaves as repellent for Ae. albopictus. The result study on 1 hr treatment showed that power protection of pandan leaves (N. scutellarium was 93.55%, while mangkokan leaves (P. amaryllifolius was 87.5%. Based on ANOVA analysis, there was not significantly different of power protection between N. scutellarium leaves and P. amaryllifolius leaves extracts against Ae. albopictus mosquitoes. Both of these test, plants has showed the potential to be a repellent and eliminate the emergence of Ae. albopictus mosquitoes, so it may effectively reduce contact between host and dengue vector.

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

    Science.gov (United States)

    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

  4. European Surveillance for West Nile Virus in Mosquito Populations

    Directory of Open Access Journals (Sweden)

    Nicholas Johnson

    2013-10-01

    Full Text Available 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.

  5. PERCEPTIONS REGARDING MOSQUITO BORNE DISEASES IN AN URBAN AREA OF RAJKOT CITY

    Directory of Open Access Journals (Sweden)

    Amul B. Patel

    2011-04-01

    Full Text Available Background: Mosquito borne diseases is a growing urban problem because of unplanned urbanization, industrialization and excessive population growth coupled with rural to urban migration. For developing a suitable and effective health education strategy, it is inevitable to understand the level of knowledge of the community, their attitude and practices regarding mosquito borne diseases. Materials and Methods: The present study was carried out in an urban field practice area of Urban Health Centre in Rajkot city. Total 500 houses were selected for study by systematic random sampling. Data was collected using a semi-structured questionnaire during transmission season of vector borne diseases. The results were analyzed using the SPSS 17 software. Results: 90% respondents agreed that mosquitoes are a problem. 30.4% didn?t know breeding sites of mosquitoes. Only 11.6% of people associated clean water collections with mosquito breeding. Regarding diseases transmitted by mosquito, 62% answered malaria, 37.4% were not aware and 8.8% people mentioned about Filariasis, Dengue or Japanese encephalitis. 4.7% granted mosquito control as responsibility of community. 61.4 % were using repellents for prevention against mosquito bites and 39% not taking any preventive measure. 67.8% consulted private practitioner for treatment. Conclusion: Intensified efforts towards creating public awareness and mobilizing the community regarding the preventive measures they can take are needed. [National J of Med Res 2011; 1(2.000: 45-47

  6. Inhibition of malaria parasite development in mosquitoes by anti-mosquito-midgut antibodies.

    OpenAIRE

    Lal, A A; Schriefer, M E; Sacci, J.B.; Goldman, I F; Louis-Wileman, V; Collins, W.E.; Azad, A F

    1994-01-01

    The mosquito midgut plays a central role in the development and subsequent transmission of malaria parasites. Using a rodent malaria parasite, Plasmodium berghei, and the mosquito vector Anopheles stephensi, we investigated the effect of anti-mosquito-midgut antibodies on the development of malaria parasites in the mosquito. In agreement with previous studies, we found that mosquitoes that ingested antimidgut antibodies along with infectious parasites had significantly fewer oocysts than mosq...

  7. A simple non-powered passive trap for the collection of mosquitoes for arbovirus surveillance.

    Science.gov (United States)

    Ritchie, Scott A; Cortis, Giles; Paton, Christopher; Townsend, Michael; Shroyer, Donald; Zborowski, Paul; Hall-Mendelin, Sonja; Van Den Hurk, Andrew F

    2013-01-01

    Mosquitoes often are collected as part of an arbovirus surveillance program. However, trapping and processing of mosquitoes for arbovirus detection is often costly and difficult in remote areas. Most traps, such as the gold standard Center for Disease control light trap, require batteries that must be charged and changed overnight. To overcome this issue we have developed several passive traps for collection of mosquitoes that have no power requirements. The passive traps capture mosquitoes as they follow a CO2 plume up a polyvinyl chloride pipe leading to a clear chamber consisting of a plastic crate. We believe the translucent, clear windows created by the crate inhibits escape. Once inside the crate mosquitoes readily feed on honey-treated Flinders Technology Associates cards that then can be processed by polymerase chain reaction for viral ribonucleic acid. Of the two designs tested, the box or crate-based passive trap (passive box trap, PBT) generally caught more mosquitoes than the cylinder trap. In Latin square field trials in Cairns and Florida, PBTs collected mosquitoes at rates of 50 to 200% of Center for Disease Control model 512 light traps. Mosquito collections by PBTs can be increased by splitting the CO2 gas line so it services two traps, or by placing an octenol lure to the outside of the box. Very large collections can lead to crowding at honey-treated cards, reducing feeding rates. Addition of fipronil to the honey killed mosquitoes and did not impact feeding rates nor the ability to detect Kunjin viral ribonucleic acid by polymerase chain reaction; this could be used to minimize crowding affects on feeding caused by large collections. The passive traps we developed are made from inexpensive, commonly available materials. Passive traps may thus be suitable for collection of mosquitoes and potentially other hematophagous dipterans for pathogen surveillance. PMID:23427669

  8. One Injection of DsRed Followed by Bites from Transgenic Mosquitoes Producing DsRed in the Saliva Elicits a High Titer of Antibody in Mice

    OpenAIRE

    Matsuoka, Hiroyuki; Sano, Gen-Ichiro; Hattori, Ryuta; Tomita, Hiroyuki; Yamamoto, Daisuke S.; Hirai,Makoto

    2012-01-01

    It has been proposed that transgenic mosquitoes can be used as a “flying syringe” for infectious disease control. We succeeded in generating a transgenic (TG) mosquito, Anopheles stephensi, excreting and discharging DsRed in saliva. DsRed was deposited on the membrane where the TG mosquito probed with its proboscis. Repeated feeding by the TG mosquitoes induced anti-DeRed as well as anti-SG antibodies in mice. This indicates that the TG mosquitoes can immunize the animal. Moreover, in thi...

  9. Señales físico químicas involucradas en la búsqueda de hospederos y en la inducción de picadura por mosquitos / Physic-chemical signals involved in host localization and induction of disease vector mosquito bites

    Scientific Electronic Library Online (English)

    José Luis, Torres-Estrada; Mario H, Rodríguez.

    2003-12-01

    Full Text Available Las hembras de los mosquitos vectores de enfermedades utilizan señales físicas y químicas para localizar su fuente de alimentación sanguínea en hospederos vertebrados. Los mosquitos zoofílicos responden preferentemente al CO2 y al octenol liberados en la respiración y excreciones, mientras que los m [...] osquitos antropofílicos responden al ácido láctico y a una variedad de compuestos del sudor. Estos compuestos son modificados por microrganismos saprófitos de las glándulas sebáceas de la piel. Otros factores presentes en las viviendas contribuyen a la integración de microsistemas constituidos por olores característicos, que explican los diferentes niveles de atracción de mosquitos y la focalización de la transmisión del paludismo a una porción de casas en localidades de áreas endémicas. La identificación de estos atrayentes químicos y sus moléculas receptoras en mosquitos puede ser utilizada como complemento de nuevos métodos para la vigilancia epidemiológica, para atraer a los mosquitos a trampas de colecta o para incrementar su contacto con insecticidas usados en su control, así como en la manipulación genética para desviar las picaduras de los mosquitos hacia otros hospederos vertebrados. Abstract in english Disease vector female mosquitoes respond to physic-chemical signals to localize vertebrate hosts for blood meals. Zoophylic mosquitoes preferentially respond to CO2 and octenol released in the breath and bodily fluids, while anthropophylic mosquitoes respond to lactic acid and a variety of sweat com [...] pounds. These compounds are modified by saprophytic microorganisms in the skin sebaceous glands. Other factors present in human dwellings contribute to the integration of microsystems with characteristic odors that have different attraction for mosquitoes, explaining the focalization of malaria transmission in few households in endemic areas. The identification of the chemical attractants and their molecular receptors could be used to complement new methods to attract mosquitoes to traps during epidemiological surveys, to increase their contact with insecticides in control interventions, and for genetic manipulation to divert mosquito bites towards other animal populations.

  10. Temporal and spatial habitat preferences and biotic interactions between mosquito larvae and antagonistic crustaceans in the field.

    Science.gov (United States)

    Kroeger, Iris; Liess, Matthias; Duquesne, Sabine

    2014-06-01

    Investigations on natural antagonists of mosquito larvae found that micro-crustaceans (e.g., Cladocera) control mosquito populations under experimental conditions. However, their relevance for mosquito control under field situations remains widely unclear because important information about habitat preferences and time of occurrence of crustaceans and mosquito larvae are still missing. In order to fill this knowledge gap, a field study was undertaken in different wetland areas of Saxony, Germany, in different habitats (i.e., grassland, forest, and reed-covered wetlands). We found negative interactions between larvae of Ae. vexans and predatory Cyclopoida (Crustacean: Copepoda), which both were dominant during the first two weeks of hydroperiod, at ponds located at grassland habitats. Larvae of Cx. pipiens were spatially associated with competing Cladocera, but they colonized ponds more rapidly. Populations of Cladocera established from the third week of hydroperiod and prevented Cx. pipiens colonization thereafter. Ostracoda were highly abundant during the whole hydroperiod, but their presence was restricted to habitats of reed-covered wetland at one geographical area. Mosquito larvae hardly occurred at those ponds. In general, we found that ponds at the reed-covered wetlands provided better conditions for the initial development of crustaceans and hence, mosquito larval colonization was strongly inhibited. Grassland habitat, in contrast, favored early development of mosquito larvae. This study showed that micro-crustaceans are relevant for mosquito management but their impact on mosquito larvae varies between species and depends on environmental conditions. PMID:24820562

  11. Molecular evidence for dual pyrethroid-receptor sites on a mosquito sodium channel

    OpenAIRE

    Du, Yuzhe; Nomura, Yoshiko; Satar, Gul; Hu, Zhaonong; Nauen, Ralf; He, Sheng Yang; Zhorov, Boris S.; Dong, Ke

    2013-01-01

    Pyrethroid insecticides are widely used as one of the most effective control measures in the global fight against agricultural arthropod pests and mosquito-borne diseases, including malaria and dengue. They exert toxic effects by altering the function of voltage-gated sodium channels, which are essential for proper electrical signaling in the nervous system. A major threat to the sustained use of pyrethroids for vector control is the emergence of mosquito resistance to pyrethroids worldwide. ...

  12. Wolbachia Induces Density-Dependent Inhibition to Dengue Virus in Mosquito Cells

    OpenAIRE

    Lu, Peng; Bian, Guowu; Pan, Xiaoling; Xi, Zhiyong

    2012-01-01

    Wolbachia is a maternal transmitted endosymbiotic bacterium that is estimated to infect up to 65% of insect species. The ability of Wolbachia to both induce viral interference and spread into mosquito vector population makes it possible to develop Wolbachia as a biological control agent for dengue control. While Wolbachia induces resistance to dengue virus in the transinfected Aedes aegypti mosquitoes, a similar effect was not observed in Aedes albopictus, which naturally carries Wolbachia in...

  13. Plasmodium knowlesi in humans, macaques and mosquitoes in peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    NorParina Ismail

    2008-08-01

    Full Text Available Abstract Background Since a large focus of human infection with Plasmodium knowlesi, a simian malaria parasite naturally found in long-tailed and pig tailed macaques, was reported in Sarawak, Malaysian Borneo, it was pertinent to study the situation in peninsular Malaysia. A study was thus initiated to screen human cases of Plasmodium malariae using molecular techniques, to determine the presence of P. knowlesi in non- human primates and to elucidate its vectors. Methods Nested polymerase chain reaction (PCR was used to identify all Plasmodium species present in the human blood samples sent to the Parasitology laboratory of Institute for Medical Research. At the same time, non-human primates were also screened for malaria parasites and nested PCR was carried out to determine the presence of P. knowlesi. Mosquitoes were collected from Pahang by human landing collection and monkey-baited-traps situated on three different levels. All mosquitoes were identified and salivary glands and midguts of anopheline mosquitoes were dissected to determine the presence of malaria parasites and nested PCR was carried out on positive glands. Sequencing of the csp genes were carried on P. knowlesi samples from humans, monkeys and mosquitoes, positive by PCR. Results and Discussion Plasmodium knowlesi was detected in 77 (69.37% of the 111 human samples, 10 (6.90% of the 145 monkey blood and in 2 (1.7% Anopheles cracens. Sequence of the csp gene clustered with other P. knowlesi isolates. Conclusion Human infection with Plasmodium knowlesi is occurring in most states of peninsular Malaysia. An. cracens is the main vector. Economic exploitation of the forest is perhaps bringing monkeys, mosquitoes and humans into increased contact. A single bite from a mosquito infected with P. knowlesi is sufficient to introduce the parasite to humans. Thus, this zoonotic transmission has to be considered in the future planning of malaria control.

  14. Higher Mosquito Production in Low-Income Neighborhoods of Baltimore and Washington, DC: Understanding Ecological Drivers and Mosquito-Borne Disease Risk in Temperate Cities

    Directory of Open Access Journals (Sweden)

    Danielle Bodner

    2013-04-01

    Full Text Available Mosquito-vectored pathogens are responsible for devastating human diseases and are (reemerging in many urban environments. Effective mosquito control in urban landscapes relies on improved understanding of the complex interactions between the ecological and social factors that define where mosquito populations can grow. We compared the density of mosquito habitat and pupae production across economically varying neighborhoods in two temperate U.S. cities (Baltimore, MD and Washington, DC. Seven species of mosquito larvae were recorded. The invasive Aedes albopictus was the only species found in all neighborhoods. Culex pipiens, a primary vector of West Nile virus (WNV, was most abundant in Baltimore, which also had more tire habitats. Both Culex and Aedes pupae were more likely to be sampled in neighborhoods categorized as being below median income level in each city and Aedes pupae density was also greater in container habitats found in these lower income neighborhoods. We infer that lower income residents may experience greater exposure to potential disease vectors and Baltimore residents specifically, were at greater risk of exposure to the predominant WNV vector. However, we also found that resident-reported mosquito nuisance was not correlated with our measured risk index, indicating a potentially important mismatch between motivation needed to engage participation in control efforts and the relative importance of control among neighborhoods.

  15. Mosquito and Blackfly Category Manual.

    Science.gov (United States)

    Bowman, James S.; And Others

    This manual provides information needed to meet the standards for pesticide applicator certification. Section one is concerned with the morphology, life cycle and breeding areas of mosquitoes and the diseases resulting from their presence. The second section covers similar categories in relation to the black fly population. Calculation methods and…

  16. [The absence of an action of the pyrethroids deltamethrin and cypermethrin on mosquito susceptibility to the causative agent of malaria].

    Science.gov (United States)

    Chunina, L M; Iakubovich, V Ia; Ganushkina, L A; Zakharova, N F; Dadasheva, N R

    1990-01-01

    Mosquitos Ae. aegypti and An. stephensi contact with sublethal doses of deltametrin and cypermetrin pyretroids at larval stage and in grown state, when diet includes sugar with pyretroids, had no influence on the sensitivity of survived females to malaria agents P. gallinaceum and P. berghei. Mosquitos under experiment showed no obvious inhibition of the physiological condition in comparison with the control ones. PMID:2191201

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

    Directory of Open Access Journals (Sweden)

    Shimada Masaaki

    2011-05-01

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

  18. The ability of Aedes aegypti mosquitoes to survive and transmit infective larvae of Brugia pahangi over successive blood meals.

    Science.gov (United States)

    Lindsay, S W; Denham, D A

    1986-09-01

    The mortality of Aedes aegypti mosquitoes increased; immediately following a blood meal containing microfilariae of Brugia pahangi, when infective larvae began to migrate out of the flight muscles and when infective larvae were lost from the mosquitoes during a blood meal. When infective mosquitoes took a second blood meal 86.2% of the infective larvae escaped from their bodies. However, only 50.3% escaped when mosquitoes fed through a thin layer of cotton. Infective larvae in the abdomen of the mosquitoes stood the least chance of escaping from the insects. When infective mosquitoes were offered a third blood meal four days later, the proportion of infective larvae in the head and labium had risen from 56.6% in the control group to 66.0% and 69.4% in the two test groups. At this third feed 54.7% and 75.7% of the infective larvae were lost from mosquitoes with a low and medium pre-feeding worm burden respectively. This suggests that the escape of infective larvae from mosquitoes with only a few worms is less efficient than from mosquitoes with a medium worm burden. PMID:3745870

  19. Efficacy of Australian quarantine procedures against the mosquito Aedes aegypti.

    Science.gov (United States)

    Ritchie, S A

    2001-06-01

    Methods employed by Australian quarantine officers to control Aedes mosquitoes in containers were tested against all stages of Aedes aegypti. Saltwater emersion killed all larvae but not pupae or eggs that were briefly exposed. Swimming pool chlorine, methyl bromide fumigation, and permethrin (2% active ingredient) spray provided 100% mortality of eggs, larvae, and pupae. Aerosol sprays incorporating synthetic pyrethrins are practical and also provide effective control of adults. PMID:11480817

  20. The population dynamics of Plasmodium within the mosquito

    OpenAIRE

    Dawes, Emma J.

    2011-01-01

    Malaria remains one of the world’s most devastating vector-borne parasitic diseases and existing control tools may not be enough to meet the challenge of eliminating malaria in areas of high transmission. Understanding the population dynamics of Plasmodium within the mosquito vector is essential for developing, optimising, and evaluating novel control measures aimed at reducing transmission by targeting this important interface. Malaria research and mathematical models of ...

  1. Understanding the DNA damage response in order to achieve desired gene editing outcomes in mosquitoes.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  3. Effectiveness of Mosquito Trap with Sugar Fermented Attractant to the Vector of Dengue Hemorrhagic Fever

    Directory of Open Access Journals (Sweden)

    Endang Puji Astuti

    2011-06-01

    Full Text Available Aedes aegypti is the main vector of dengue fever that is still become health problem in the world. Various control efforts has been done at several areas through chemically or naturally control. Developing mosquitoes trapping tool is an alternative method to control mosquitoes besides insecticides utilization. This laboratorium research utilize sugar fermented process to yield CO2 as one of attractan to mosquito. Production of ethanol and CO2 can be yielded from anaerob sugar fermentation proccess (without O2 by khamir Saccharomyces cerevisiae activities. The trapped mosquitoes was observed up to 48 hours exposure, the highest average of mosquito trapped is on solution treatment with yeast 1 gram (43.2% and 40 gr sugar (48.4%. The highest effectivity of trapping tool both inside or outside was on the 14th day. There were declained amount of trapped mosquitos on 16th and 18th days. This laboratorium research has described that trapping tool with sugar fermented solution were effective to control population of dengue vector.

  4. Biodistribution and Trafficking of Hydrogel Nanoparticles in Adult Mosquitoes

    Science.gov (United States)

    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

  5. Susceptibility of various mosquitoes of California to subperiodic Brugia malayi.

    Science.gov (United States)

    Bangs, M J; Ash, L R; Barr, A R

    1995-08-01

    Laboratory experiments were conducted to determine the susceptibility of six species of mosquitoes, representing three genera, to subperiodic Brugia malayi. The black-eye, Liverpool strain of Aedes aegypti was the susceptible control. Mosquitoes were fed on microfilaremic jirds (Meriones unguiculatus). All mosquitoes, except wild caught Culex erythrothorax, were laboratory-reared and allowed to feed when 8 to 10 days old. Anopheles freeborni, Anopheles hermsi, and Culiseta inornata proved refractory. Both Anopheles species allowed invasion of flight muscle and development to the late first stage, after which larval growth ceased and melanization occurred. Culiseta inornata prevented any larval development. Culex tarsalis and Cx. erythrothorax proved highly susceptible to B. malayi infection. In all, 95.6% and 88.7% of the Cx. tarsalis harbored third-stage larvae after infective feedings of 15.7 and 81.8 mf/microliters of blood, respectively, while only 11.5% were found susceptible when microfilaremia was low (1.1 mf/microliters). Culex erythrothorax demonstrated a susceptibility rate of 82.3% with 17.0 mf/microliters. Both Culex species appear to be excellent experimental hosts for subperiodic B. malayi. This is the first conclusive evidence that mosquitoes of the genus Culex can naturally support the complete development of a stain of subperiodic B. malayi. PMID:8533667

  6. Modelling parasitism and predation of mosquitoes by water mites.

    Science.gov (United States)

    Esteva, Lourdes; Rivas, Gerardo; Yang, Hyun Mo

    2006-10-01

    Parasitism and predation are two ecological interactions that can occur simultaneously between two species. This is the case of Culicidae (Insecta: Diptera) and water mites (Acari: Hydrachnidia). The larva mites are~parasites of aquatic and semiaquatic insects, and deutonymphs and adults are predators of insect larvae and eggs. Since several families of water mites are associated with mosquitoes there is an interest in the potential use of these mites as biological control agents. The aim of this paper is to use mathematical modelling and analysis to assess the impact of predation and parasitism in the mosquito population. We propose a system of ordinary differential equations to model the interactions among the larval and adult stages of mosquitoes and water mites. The model exhibits three equilibria: the first equilibrium point corresponds to the state where the two species are absent, the second one to the state where only mosquitoes are present (water mites need insects to complete their life cycle), and the third one is the coexistence equilibrium. We analyze conditions for the asymptotic stability of equilibria, supported by analytical and numerical methods. We discuss the different scenarios that appear when we change the parasitism and predation parameters. High rates of parasitism and moderate predation can drive two species to a stable coexistence. PMID:16897016

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

    Science.gov (United States)

    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

  8. Wash resistance and repellent properties of Africa University mosquito blankets against mosquitoes

    Directory of Open Access Journals (Sweden)

    M. Zimba

    2013-04-01

    Full Text Available The effect of permethrin-treated Africa University (AU mosquito blankets on susceptible female Anopheles gambiae sensu lato mosquitoes was studied under laboratory conditions at Africa University Campus in Mutare, Zimbabwe. Wash resistance (ability to retain an effective dose that kills ?80% of mosquitoes after a number of washes and repellence (ability to prevent ?80% of mosquito bites properties were studied. The AU blankets were wash resistant when 100% mortality was recorded up to 20 washes, declining to 90% after 25 washes. Untreated AU blankets did not cause any mortality on mosquitoes. However, mosquito repellence was 96%, 94%, 97.9%, 87%, 85% and 80.7% for treated AU blankets washed 0, 5, 10, 15, 20 and 25 times, respectively. Mosquito repellence was consistently above 80% from 0-25 washes. In conclusion, AU blankets washed 25 times were effective in repelling and killing An. gambiae sl mosquitoes under laboratory conditions.

  9. Nationwide Investigation of the Pyrethroid Susceptibility of Mosquito Larvae Collected from Used Tires in Vietnam

    OpenAIRE

    Kawada, Hitoshi; Higa, Yukiko; Nguyen, Yen T.; Tran, Son H.; Nguyen, Hoa T.; Takagi, Masahiro

    2009-01-01

    Pyrethroid resistance is envisioned to be a major problem for the vector control program since, at present, there are no suitable chemical substitutes for pyrethroids. Cross-resistance to knockdown agents, which are mainly used in mosquito coils and related products as spatial repellents, is the most serious concern. Since cross-resistance is a global phenomenon, we have started to monitor the distribution of mosquito resistance to pyrethroids. The first pilot study was carried out in Vietnam...

  10. A push-pull system to reduce house entry of malaria mosquitoes

    OpenAIRE

    Menger, David J; Otieno, Bruno; de Rijk, Marjolein; Mukabana, W Richard; van Loon, Joop Ja; TAKKEN, WILLEM

    2014-01-01

    Background. Mosquitoes are the dominant vectors of pathogens that cause infectious diseases such as malaria, dengue, yellow fever and filariasis. Current vector control strategies often rely on the use of pyrethroids against which mosquitoes are increasingly developing resistance. Here, a push-pull system is presented, that operates by the simultaneous use of repellent and attractive volatile odorants. Method/Results. Experiments were carried out in a semi-field set-up: a traditional house wh...

  11. Wash resistance and repellent properties of Africa University mosquito blankets against mosquitoes

    OpenAIRE

    Zimba, M.; Mutambu, S. L.; Chiwade, T.; Makuwaza, A.; Lukwa, N.; Munosiyei, P.

    2013-01-01

    The effect of permethrin-treated Africa University (AU) mosquito blankets on susceptible female Anopheles gambiae sensu lato mosquitoes was studied under laboratory conditions at Africa University Campus in Mutare, Zimbabwe. Wash resistance (ability to retain an effective dose that kills ?80% of mosquitoes after a number of washes) and repellence (ability to prevent ?80% of mosquito bites) properties were studied. The AU blankets were wash resistant when 100% mortality was recorded up t...

  12. Free flight of the mosquito Aedes aegypti

    OpenAIRE

    Iams, S. M.

    2012-01-01

    High speed video observations of free flying male Aedes aegypti mosquitoes, the dengue and yellow fever vector, along with custom measurement methods, enable measurement of wingbeat frequency, body position and body orientation of mosquitoes during flight. We find these mosquitoes flap their wings at approximately 850 Hz. We also generate body yaw, body pitch and wing deviation measurements with standard deviations of less than 1 degree and find that sideways velocity and ac...

  13. Malaria Mosquitoes Attracted by Fatal Fungus

    OpenAIRE

    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...

  14. Evaluación de la trampa Mosquito Magnet® con y sin octenol para capturar mosquitos (Diptera: Culicidae) / Evaluation of the Mosquito Magnet® trap with and without octenol to collect mosquitoes (Diptera: Culicidae)

    Scientific Electronic Library Online (English)

    Yasmin, Rubio-Palis; Rodrigo, Ramírez Álvarez; Hernán, Guzmán; Yarys, Estrada.

    2014-06-01

    Full Text Available La eficiencia de la trampa Mosquito Magnet® Liberty Plus (MMLP) fue evaluada con y sin octenol para capturar mosquitos hembras adultas en Maracay, estado Aragua, Venezuela. Se realizaron capturas dos veces por semana entre las 3:00 pm y 10:00 am, un día con y otro sin octenol, durante ocho semanas e [...] ntre abril y mayo 2013 para un total de 152 horas de capturas para cada tratamiento. Se capturaron un total de 229 especímenes pertenecientes a 10 especies distribuidas en cinco géneros. En general, se capturó un número similar de mosquitos con y sin octenol. No se observaron diferencias significativas entre ambos tratamientos para las especies más abundantes (Anopheles pseudopunctipennis y Aedes angustivittatus) así como para el total de mosquitos capturados. Para ambos tratamientos se capturaron proporciones similares de hembras de Aedes aegypti y Ae. albopictus. Sin embargo, se capturaron significativamente más Culex quinquefasciatus sin octenol que con octenol. Los resultados sugieren que es factible prescindir del uso de octenol en trampas MMLP en futuros estudios de vigilancia entomológica para la prevención y control de la malaria, dengue y otros arbovirus, particularmente en áreas remotas. Sin embargo, es fundamental realizar más evaluaciones en áreas endémicas en épocas de alta abundancia de mosquitos a fin de obtener una mejor estimación de la eficacia de la trampa con y sin octenol. Abstract in english The efficiency of the Mosquito Magnet® Liberty Plus (MMLP) trap was evaluated with and without octenol for the capture of adult female mosquitoes in Maracay, Aragua state, Venezuela. Captures were carried out twice a week between 3:00 pm and 10:00 am, one day with octenol and the following without i [...] t, during 8 weeks between April and May, 2013 with a total of 152 hours of sampling effort per treatment. A total of 229 specimens belonging to 10 species distributed in 5 genera were caught. In general, similar numbers of mosquitoes were caught in traps both with and without octenol. No significant differences were observed between the two treatments for the two most abundant species (Anopheles pseudopunctipennis and Aedes angustivittatus) or for the total number of mosquitoes captured. Similar proportions of Aedes aegypti and Ae. albopictus females were also captured independent of the treatment used. However, significantly more Culex quinquefasciatus were caught in the traps without octenol. The results suggest that it is feasible to use the MMLP traps without octenol in future studies of entomological surveillance for the prevention and control of malaria, dengue and other arboviruses, especially in remote areas. Nevertheless, further evaluations in endemic areas should be done during periods of higher mosquito abundance in order to obtain a more precise estimate of the effectiveness of traps with and without octenol.

  15. [The pathogens of Taiwan mosquitoes--Coelomomyces species].

    Science.gov (United States)

    Lien, J C; Lin, Y N

    1990-07-01

    A brief mention was made of the history of world studies on the Coelomomyces fungi, the life cycle of the fungi, their importance as biological agents for mosquito control, and the known ecological information concerning the Taiwan mosquitoes parasitized by the fungi. Special accounts were made of the results of experiments infecting four mosquito species, Aedes aegypti, Ae. albopictus, Ae. triseriatus and Tripteroides aranoides with Coelomomyces stegomyiae var. chapmani, using the copepod, Phyllognathopus viguieri as an alternate host. The dead 4th instar larvae of Ae. albopictus containing sporangia were put together with healthy copepods for 10 days, then healthy 2nd instar mosquito larvae were added for a 1-day exposure. Then the larvae were transferred to clean water and subsequent examinations for signs of infection were made at 3-day intervals for a period of 21 days. The experiments demonstrated an infection rate of 59.7% and 90% respectively for Ae. albopictus and Ae. aegypti in the first trial, 18.5% and 23.3% in the 2nd trial, and none in the 3rd trial. The low infection rate in the 2nd trial and no infection in the 3rd trial were thought to be due to the extensive contamination of test water with algae. Therefore, in the 4th trial the rearing water was renewed with dechlorinated tap water and new copepods instroduced. The infection rate again rose to 41.1% and 56% respectively for the two species. Experiments with Ae. triseriatus and Tp. aranoides failed to produce signs of infection. Experimental infection of susceptible Ae. albopictus larvae with the sporangia stored at 8 degrees C showed that storage for one month produced an infection rate of 38.2%. However, storage for two months or longer produced no infection in the larvae of the same mosquito species. PMID:1976138

  16. Mosquito repellent action of Blumea lacera (Asteraceae against Anopheles stephensi and Culex quinquefasciatus.

    Directory of Open Access Journals (Sweden)

    S.P. Singh

    2014-03-01

    Full Text Available Petroleum ether extract of Blumea lacera was screened under laboratory conditions for repellent activity against mosquito vector Anopheles stephensi Liston and Culex quinquefasciatus Say (Diptera: Culicidae. The repellent activity of Blumea lacera extract was tested against mosquitoes in comparison with the DEET, which was used as a positive control. Results obtained from the laboratory experiment showed that the extract was effective against mosquito vectors even at a low dose. A direct relationship was observed with concentrations of Blumea lacera extract and the repellent activity. Percent repellency obtained at 6% concentration of theextract against An. stephensi and Cx. quinquefasciatus were 97and 98% at 0 hour and 78.8 and 76.2% after 6 hrs. DEET-2% however showed 100% repellency against An. stephensi and against Cx. quinquefasciatus up to 4 hours and 1 hour, respectively. These results show that Blumea lacera extract has the potential as an effective mosquito repellent.

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

    Science.gov (United States)

    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

  18. Gametocytes infectiousness to mosquitoes: variable selection using random forests, and zero inflated models

    CERN Document Server

    Genuer, Robin; Toussile, Wilson

    2011-01-01

    Malaria control strategies aiming at reducing disease transmission intensity may impact both oocyst intensity and infection prevalence in the mosquito vector. Thus far, mathematical models failed to identify a clear relationship between Plasmodium falciparum gametocytes and their infectiousness to mosquitoes. Natural isolates of gametocytes are genetically diverse and biologically complex. Infectiousness to mosquitoes relies on multiple parameters such as density, sex-ratio, maturity, parasite genotypes and host immune factors. In this article, we investigated how density and genetic diversity of gametocytes impact on the success of transmission in the mosquito vector. We analyzed data for which the number of covariates plus attendant interactions is at least of order of the sample size, precluding usage of classical models such as general linear models. We then considered the variable importance from random forests to address the problem of selecting the most influent variables. The selected covariates were ...

  19. Attracting, trapping and killing disease-transmitting mosquitoes using odor-baited stations - The Ifakara Odor-Baited Stations

    Directory of Open Access Journals (Sweden)

    John Alex N

    2010-03-01

    Full Text Available Abstract Background To accelerate efforts towards control and possibly elimination of mosquito-borne diseases such as malaria and lymphatic filariasis, optimally located outdoor interventions could be used to complement existing intradomicilliary vector control methods such as house spraying with insecticides and insecticidal bednets. Methods We describe a new odor-baited station for trapping, contaminating and killing disease-transmitting mosquitoes. This device, named the 'Ifakara Odor-baited Station' (Ifakara OBS, is a 4 m3 hut-shaped canvas box with seven openings, two of which may be fitted with interception traps to catch exiting mosquitoes. It is baited with synthetic human odors and may be augmented with contaminants including toxic insecticides or biological agents. Results In field trials where panels of fabric were soaked in 1% pirimiphos-methyl solution and suspended inside the Ifakara OBS, at least 73.6% of Anopheles arabiensis, 78.7% of Culex and 60% of Mansonia mosquitoes sampled while exiting the OBS, died within 24 hours. When used simply as a trap and evaluated against two existing outdoor traps, Ifakara Tent trap and Mosquito Magnet-X®, the OBS proved more efficacious than the Ifakara Tent trap in catching all mosquito species found (P ®, it was equally efficacious in catching An. arabiensis (P = 0.969, but was less efficacious against Culex (P Mansonia species (P Conclusion The Ifakara OBS is efficacious against disease-carrying mosquitoes including the malaria vector, An. arabiensis and Culicine vectors of filarial worms and arboviruses. It can be used simultaneously as a trap and as a contamination or killing station, meaning most mosquitoes which escape trapping would leave when already contaminated and die shortly afterwards. This technique has potential to complement current vector control methods, by targeting mosquitoes in places other than human dwellings, but its effectiveness in the field will require cheap, long-lasting and easy-to-use mosquito lures.

  20. The entomopathogenic fungus Beauveria bassiana reduces instantaneous blood feeding in wild multi-insecticide-resistant Culex quinquefasciatus mosquitoes in Benin, West Africa

    OpenAIRE

    Howard Annabel FV; N'guessan Raphael; Koenraadt Constantianus JM; Asidi Alex; Farenhorst Marit; Akogbéto Martin; Thomas Matthew B; Knols Bart GJ; Takken Willem

    2010-01-01

    Abstract Background Mosquito-borne diseases are still a major health risk in many developing countries, and the emergence of multi-insecticide-resistant mosquitoes is threatening the future of vector control. Therefore, new tools that can manage resistant mosquitoes are required. Laboratory studies show that entomopathogenic fungi can kill insecticide-resistant malaria vectors but this needs to be verified in the field. Methods The present study investigated whether these fungi will be effect...

  1. Hemocyte alterations during melanotic encapsulation of Brugia malayi in the mosquito Armigeres subalbatus.

    Science.gov (United States)

    Guo, X; Beerntsen, B T; Zhao, X; Christensen, B M

    1995-04-01

    The involvement of hemocytes in melanotic encapsulation reactions against Brugia malayi was assessed in Armigeres subalbatus. Hemocyte populations, epitope changes, phenol oxidase (PO) activity, and the presence of an 84-kDa polypeptide were investigated in mosquitoes exposed to a B. malayi-infective bloodmeal (= immune-activated), in mosquitoes given a noninfective bloodmeal (= controls), in nonbloodfed mosquitoes (= naive), or in some combination of these. Total hemocyte populations in immune-activated mosquitoes significantly decreased at 24 hr postbloodmeal (PB) as compared with controls. At 48 and 72 hr PB, hemocyte population levels in immune-activated mosquitoes increased to control levels. Epitope changes, as indicated by wheat germ agglutinin (WGA) binding, also were observed. There was a significant increase in the percentage of hemocytes binding WGA in immune-activated mosquitoes at 24 hr PB as compared with controls. Furthermore, the activity of hemocyte PO, an enzyme involved in the melanotic encapsulation pathway, was significantly elevated at 12 hr PB in immune-activated mosquitoes as compared with controls. Analysis for the presence of an 84-kDa polypeptide in A. subalbatus indicates that a 2.0-kb message in total RNA hybridized to D6.12, an Aedes aegypti cDNA encoding an 84-kDa polypeptide that is associated with melanotic encapsulation responses. The hybridization of D6.12 to RNA was not greater in immune-activated as compared to control A. subalbatus, as has been observed in A. aegypti. Results indicate that these hemocyte changes correspond in time with the melanotic encapsulation reactions of A. subalbatus against filarial worms. PMID:7535848

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

    OpenAIRE

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Dua Virendra K

    2009-06-01

    Full Text Available Abstract Background Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of botanical origin have been reported as useful for control of mosquitoes. Azadirachta indica (Meliaceae and its derived products have shown a variety of insecticidal properties. The present paper discusses the larvicidal activity of neem-based biopesticide for the control of mosquitoes. Methods Larvicidal efficacy of an emulsified concentrate of neem oil formulation (neem oil with polyoxyethylene ether, sorbitan dioleate and epichlorohydrin developed by BMR & Company, Pune, India, was evaluated against late 3rd and early 4th instar larvae of different genera of mosquitoes. The larvae were exposed to different concentrations (0.5–5.0 ppm of the formulation along with untreated control. Larvicidal activity of the formulation was also evaluated in field against Anopheles, Culex, and Aedes mosquitoes. The formulation was diluted with equal volumes of water and applied @ 140 mg a.i./m2 to different mosquito breeding sites with the help of pre calibrated knapsack sprayer. Larval density was determined at pre and post application of the formulation using a standard dipper. Results Median lethal concentration (LC50 of the formulation against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti was found to be 1.6, 1.8 and 1.7 ppm respectively. LC50 values of the formulation stored at 26°C, 40°C and 45°C for 48 hours against Ae. aegypti were 1.7, 1.7, 1.8 ppm while LC90 values were 3.7, 3.7 and 3.8 ppm respectively. Further no significant difference in LC50 and LC90 values of the formulation was observed against Ae. aegypti during 18 months storage period at room temperature. An application of the formulation at the rate of 140 mg a.i./m2 in different breeding sites under natural field conditions provided 98.1% reduction of Anopheles larvae on day 1; thereafter 100% reduction was recorded up to week 1 and more than 80% reduction up to week 3, while percent reduction against Culex larvae was 95.5% on day 1, and thereafter 80% reduction was achieved up to week 3. The formulation also showed 95.1% and, 99.7% reduction of Aedes larvae on day 1 and day 2 respectively; thereafter 100% larval control was observed up to day 7. Conclusion The neem oil formulation was found effective in controlling mosquito larvae in different breeding sites under natural field conditions. As neem trees are widely distributed in India, their formulations may prove to be an effective and eco-friendly larvicide, which could be used as an alternative for malaria control.

  4. Increased Akt signaling in the mosquito fat body increases adult survivorship.

    Science.gov (United States)

    Arik, Anam J; Hun, Lewis V; Quicke, Kendra; Piatt, Michael; Ziegler, Rolf; Scaraffia, Patricia Y; Badgandi, Hemant; Riehle, Michael A

    2015-04-01

    Akt signaling regulates diverse physiologies in a wide range of organisms. We examine the impact of increased Akt signaling in the fat body of 2 mosquito species, the Asian malaria mosquito Anopheles stephensi and the yellow fever mosquito Aedes aegypti. Overexpression of a myristoylated and active form of A. stephensi and Ae. aegypti Akt in the fat body of transgenic mosquitoes led to activation of the downstream signaling molecules forkhead box O (FOXO) and p70 S6 kinase in a tissue and blood meal-specific manner. In both species, increased Akt signaling in the fat body after blood feeding significantly increased adult survivorship relative to nontransgenic sibling controls. In A. stephensi, survivorship was increased by 15% to 45%, while in Ae. aegypti, it increased 14% to 47%. Transgenic mosquitoes fed only sugar, and thus not expressing active Akt, had no significant difference in survivorship relative to nontransgenic siblings. Expression of active Akt also increased expression of fat body vitellogenin, but the number of viable eggs did not differ significantly between transgenic and nontransgenic controls. This work demonstrates a novel mechanism of enhanced survivorship through increased Akt signaling in the fat bodies of multiple mosquito genera and provides new tools to unlock the molecular underpinnings of aging in eukaryotic organisms. PMID:25550465

  5. Insilico modeling of Wolbachia and its potentials in combating mosquito borne diseases Chikungunya and Dengue

    Directory of Open Access Journals (Sweden)

    N.M.Guruprasad

    2013-09-01

    Full Text Available Mosquito borne diseases are major health burden both in tropical and subtropical regions. The enormous use of insecticides to control mosquitoes causes biomagnification of chemicals in environment and mosquitoes have developed resistance to insecticides. The inefficiency of insecticides to combat mosquitoes prompted researchers to develop efficient alternative methods. Wolbachia endosymbiont is a one of efficient new approach to control mosquitoes. Wolbachia strain invade mosquitoes biology by reducing host lifespan, phenotype and inhibit virus replication. In the present study, insilico modeling and docking of Wolbachia and human pathogens Chikungunya (CHIK and Dengue (DEN virus was done. Docking is the method to find the binding affinity of protein and ligand complex molecules for finding potential inhibitor. Using Hex, we obtained energy total (e-total values in kcal/mol for all docked complex. In the contest of overall analyzing the docking E-total values of docked complexes reveals that WSP-B has show strong binding affinity than WSP-A to both DEN and CHIK. Based on obtained result, we suggest WSP-B has potential inhibitor for both DEN and CHIK virus. Further, biophysical characterization of Wolbachia will help to develop a drug to combat CHIK and DEN viruses.

  6. Mosquito and Fly Control Research by the USDA-ARS Center for Medical, Agriculture and Veterinary Entomology (CMAVE) in the Deployed War-Fighter Protection (DWFP) Program

    Science.gov (United States)

    Despite existing measures to prevent and control arthropod-borne diseases in military units, these diseases continue to be serious threats to deployed troops. Due to a shrinking list of safe, cost-effective pesticides for control of disease vectors, new and improved toxicants and methods for deliver...

  7. Can Wolbachia be used to control malaria?

    Scientific Electronic Library Online (English)

    Thomas, Walker; Luciano Andrade, Moreira.

    2011-08-01

    Full Text Available Malaria is a mosquito-borne infectious disease caused by Plasmodium parasites transmitted by the infectious bite of Anopheles mosquitoes. Vector control of malaria has predominantly focused on targeting the adult mosquito through insecticides and bed nets. However, current vector control methods are [...] often not sustainable for long periods so alternative methods are needed. A novel biocontrol approach for mosquito-borne diseases has recently been proposed, it uses maternally inherited endosymbiotic Wolbachia bacteria transinfected into mosquitoes in order to interfere with pathogen transmission. Transinfected Wolbachia strains in Aedes aegypti mosquitoes, the primary vector of dengue fever, directly inhibit pathogen replication, including Plasmodium gallinaceum, and also affect mosquito reproduction to allow Wolbachia to spread through mosquito populations. In addition, transient Wolbachia infections in Anopheles gambiae significantly reduce Plasmodium levels. Here we review the prospects of using a Wolbachia-based approach to reduce human malaria transmission through transinfection of Anopheles mosquitoes.

  8. Can Wolbachia be used to control malaria?

    Directory of Open Access Journals (Sweden)

    Thomas Walker

    2011-08-01

    Full Text Available Malaria is a mosquito-borne infectious disease caused by Plasmodium parasites transmitted by the infectious bite of Anopheles mosquitoes. Vector control of malaria has predominantly focused on targeting the adult mosquito through insecticides and bed nets. However, current vector control methods are often not sustainable for long periods so alternative methods are needed. A novel biocontrol approach for mosquito-borne diseases has recently been proposed, it uses maternally inherited endosymbiotic Wolbachia bacteria transinfected into mosquitoes in order to interfere with pathogen transmission. Transinfected Wolbachia strains in Aedes aegypti mosquitoes, the primary vector of dengue fever, directly inhibit pathogen replication, including Plasmodium gallinaceum, and also affect mosquito reproduction to allow Wolbachia to spread through mosquito populations. In addition, transient Wolbachia infections in Anopheles gambiae significantly reduce Plasmodium levels. Here we review the prospects of using a Wolbachia-based approach to reduce human malaria transmission through transinfection of Anopheles mosquitoes.

  9. Elevation of dopamine level reduces host-seeking activity in the adult female mosquito Aedes albopictus

    Directory of Open Access Journals (Sweden)

    Fukumitsu Yuki

    2012-05-01

    Full Text Available Abstract Background Mosquito-borne viruses are transmitted to human hosts via blood-feeding behavior of female mosquitoes. Female mosquitoes seek a host to take blood meals (host-seeking behavior. In order to prevent virus infections, it is important to understand how they modulate host-seeking behavior. Dopamine (DA in the central nervous system acts as a neuromediator that regulates a variety of behaviors in insects. In female mosquitoes, host-seeking behavior increases when DA levels in the head decline after emergence. However, it remains unclear whether DA directly modulates host-seeking behavior in female mosquitoes. The aim of this study was to examine whether changes in DA levels in the head affects host-seeking activity in the adult female mosquito Aedes albopictus (Ae. albopictus. Findings We compared host-seeking behavior in one group of emerging female adults treated with l-?-3,4-dihydroxyphenylalanine (l-DOPA, the precursor of DA, (l-DOPA group, with that in an untreated control (control group after confirming elevation of head DA in l-DOPA group by using high-performance liquid chromatography. The content of head DA in l-DOPA group significantly remained higher than that in controls on all days examined. The host-seeking activity in the control group showed a gradual increase over the 6-day experimental period. In contrast, there was no such increase in the host-seeking activity in the l-DOPA group. Therefore, the host-seeking activity of l-DOPA group was significantly lower than that of the controls between day 3 and 6 post-emergence. Conclusion Our results indicate that elevation of DA level reduces host-seeking activity in adult female mosquito Ae. albopictus.

  10. Transcription profiling of resistance to Bti toxins in the mosquito Aedes aegypti using next-generation sequencing.

    Science.gov (United States)

    Paris, Margot; Melodelima, Christelle; Coissac, Eric; Tetreau, Guillaume; Reynaud, Stephane; David, Jean-Philippe; Despres, Laurence

    2012-02-01

    The control of mosquitoes transmitting infectious diseases relies mainly on the use of chemical insecticides. However, resistance to most chemical insecticides threatens mosquito control programs. In this context, the spraying of toxins produced by the bacteria Bacillus thuringiensis subsp. israelensis (Bti) in larval habitats represents an alternative to chemical insecticides and is now widely used for mosquito control. Recent studies suggest that resistance of mosquitoes to Bti toxin may occur locally but mechanisms have not been characterized so far. In the present study, we investigated gene transcription level variations associated with Bti toxin resistance in the mosquito Aedes aegypti using a next-generation sequencing approach. More than 6 million short cDNA tags were sequenced from larvae of two strains sharing the same genetic background: a Bti toxins-resistant strain and a susceptible strain. These cDNA tags were mapped with a high coverage (308 reads per position in average) to more than 6000 genes of Ae. aegypti genome and used to quantify and compare the transcription level of these genes between the two mosquito strains. Among them, 86 genes were significantly differentially transcribed more than 4-fold in the Bti toxins resistant strain comparatively to the susceptible strain. These included gene families previously associated with Bti toxins resistance such as serine proteases, alkaline phosphatase and alpha-amylase. These results are discussed in regards of potential Bti toxins resistance mechanisms in mosquitoes. PMID:22115744

  11. Anopheline and culicine mosquitoes are not repelled by surfaces treated with the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    Mnyone Ladslaus L

    2010-08-01

    Full Text Available Abstract Background Entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, are promising bio-pesticides for application against adult malaria mosquito vectors. An understanding of the behavioural responses of mosquitoes towards these fungi is necessary to guide development of fungi beyond the 'proof of concept' stage and to design suitable intervention tools. Methods Here we tested whether oil-formulations of the two fungi could be detected and avoided by adult Anopheles gambiae s.s., Anopheles arabiensis and Culex quinquefasciatus. The bioassays used a glass chamber divided into three compartments (each 250 × 250 × 250 mm: release, middle and stimulus compartments. Netting with or without fungus was fitted in front of the stimulus compartment. Mosquitoes were released and the proportion that entered the stimulus compartment was determined and compared between treatments. Treatments were untreated netting (control 1, netting with mineral oil (control 2 and fungal conidia formulated in mineral oil evaluated at three different dosages (2 × 1010, 4 × 1010 and 8 × 1010 conidia m-2. Results Neither fungal strain was repellent as the mean proportion of mosquitoes collected in the stimulus compartment did not differ between experiments with surfaces treated with and without fungus regardless of the fungal isolate and mosquito species tested. Conclusion Our results indicate that mineral-oil formulations of M. anisopliae and B. bassiana were not repellent against the mosquito species tested. Therefore, both fungi are suitable candidates for the further development of tools that aim to control host-seeking or resting mosquitoes using entomopathogenic fungi.

  12. Mass production of Coelomomyes, a fungus that kills mosquitoes.

    Science.gov (United States)

    Couch, J N

    1972-08-01

    In work on the control of mosquitoes by the fungus Coelomomyces, the main problem is a source of inoculum since the fungus has not been cultured artificially with production of sporangia. We reared the larvae of Anopheles quadrimaculatus in algal water instead of in water with soil. By addition of inoculum once or twice in small amounts, the larvae become infected, and many grow to large fourth instars whose bodies are filled with sporangia. Such larvae are perfect for inoculum. If inoculum is added in much larger amounts and so timed that sporangia will be discharging spores during the first, second, and third ecdyses up to 100%, infection occurs, most of the larvae dying as late second or early third instars. This type of infection is good for extermination of mosquitoes but not for production of inoculum. Crude field tests have averaged 60% infection. PMID:4506071

  13. Mass Production of Coelomomyces, a Fungus That Kills Mosquitoes

    Science.gov (United States)

    Couch, J. N.

    1972-01-01

    In work on the control of mosquitoes by the fungus Coelomomyces, the main problem is a source of inoculum since the fungus has not been cultured artificially with production of sporangia. We reared the larvae of Anopheles quadrimaculatus in algal water instead of in water with soil. By addition of inoculum once or twice in small amounts, the larvae become infected, and many grow to large fourth instars whose bodies are filled with sporangia. Such larvae are perfect for inoculum. If inoculum is added in much larger amounts and so timed that sporangia will be discharging spores during the first, second, and third ecdyses up to 100%, infection occurs, most of the larvae dying as late second or early third instars. This type of infection is good for extermination of mosquitoes but not for production of inoculum. Crude field tests have averaged 60% infection. Images PMID:4506071

  14. Screening of Rubiaceae and Apocynaceae extracts for mosquito larvicidal potential.

    Science.gov (United States)

    Suryawanshi, Rahul; Patil, Chandrashekhar; Borase, Hemant; Narkhede, Chandrakant; Patil, Satish

    2015-01-01

    Rubiaceae and Apocynaceae families are well known for the expression of cyclotides having insecticidal properties. Leaves and flowers extracts of plants from the families Rubiaceae (Ixora coccinea) and Apocynaceae (Allamanda violacea) were evaluated for mosquito larvicidal effect against early IVth instars of Aedes aegypti and Anopheles stephensi. Two forms of plant extracts, one untreated and the other treated with heat and proteolytic enzyme were used for assay. After primary assay, the extract showing more than 50% inhibition was further used for quantification purpose. LC50 and LC90 values of all the extracts were found to be reduced with the treated form. Phytochemical analysis of plant extracts was performed. Primary confirmation for the presence of cyclotides was done by Lowry test, thin layer chromatography and haemolytic assay. This novel approach merits use of plant extracts in mosquito control programmes. PMID:25317964

  15. Understanding the Long-Lasting Attraction of Malaria Mosquitoes to Odor Baits

    Science.gov (United States)

    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

  16. Olfactory responses of the antennal trichoid sensilla to chemical repellents in the mosquito, Culex quinquefasciatus.

    Science.gov (United States)

    Liu, Feng; Chen, Li; Appel, Arthur G; Liu, Nannan

    2013-11-01

    Insect repellents are widely used to protect against insect bites and thus prevent allergic reaction and the spread of disease. To gain insight into the mosquito's response to chemicals repellents, we investigated the interaction between the olfactory system of the mosquito Culex quinquefasciatus Say and chemical repellents using single sensillum recording. The interactions of 50 repellent chemicals with olfactory receptor neurons were measured in six different types of mosquito sensilla: long sharp trichoid (LST), short sharp trichoid (SST), short blunt trichoid I (SBT-I), short blunt trichoid II (SBT-II), short blunt trichoid-curved (SBT-C), and grooved peg (GP). A single olfactory neuron reacted to the chemical repellents in each of the sensilla except for SBT-I and SBT-II, where two neurons were involved. Other than LST and GP, which showed no or very weak responses to the repellents tested, all the sensilla showed significant excitatory responses to certain types of repellents. Terpene-derived chemicals such as eucalyptol, ?-pinene, and camphor, stimulated olfactory receptor neurons in a dose-dependent manner and mosquitoes responded more strongly to terpene-derived chemical repellents than to non-terpene-derived chemicals such as dimethyl phthalate. Mosquitoes also exhibited a similar response to stereoisomers of chemicals such as (-)-?-pinene versus (+)-?-pinene, and (-)-menthone versus (+)-menthone. This study not only demonstrates the effects of chemical repellents on the mosquito olfactory system but also provides important information that will assist those screening new mosquito repellents and designing new mosquito control agents. PMID:24035746

  17. A Critical Role for CLSP2 in the Modulation of Antifungal Immune Response in Mosquitoes.

    Science.gov (United States)

    Wang, Yan-Hong; Hu, Yang; Xing, Long-Sheng; Jiang, Hong; Hu, Song-Nian; Raikhel, Alexander S; Zou, Zhen

    2015-06-01

    Entomopathogenic fungi represent a promising class of bio-insecticides for mosquito control. Thus, detailed knowledge of the molecular mechanisms governing anti-fungal immune response in mosquitoes is essential. In this study, we show that CLSP2 is a modulator of immune responses during anti-fungal infection in the mosquito Aedes aegypti. With a fungal infection, the expression of the CLSP2 gene is elevated. CLSP2 is cleaved upon challenge with Beauveria bassiana conidia, and the liberated CLSP2 CTL-type domain binds to fungal cell components and B. bassiana conidia. Furthermore, CLPS2 RNA interference silencing significantly increases the resistance to the fungal challenge. RNA-sequencing transcriptome analysis showed that the majority of immune genes were highly upregulated in the CLSP2-depleted mosquitoes infected with the fungus. The up-regulated immune gene cohorts belong to melanization and Toll pathways, but not to the IMD or JAK-STAT. A thioester-containing protein (TEP22), a member of ?2-macroglobulin family, has been implicated in the CLSP2-modulated mosquito antifungal defense. Our study has contributed to a greater understanding of immune-modulating mechanisms in mosquitoes. PMID:26057557

  18. Predation on Mosquito Larvae by Mesocyclops thermocyclopoides (Copepoda: Cyclopoida) in the Presence of Alternate Prey

    Science.gov (United States)

    Kumar, Ram; Ramakrishna Rao, T.

    2003-11-01

    The cyclopoid copepod Mesocyclops thermocyclopoides, a dominant invertebrate predator in many shallow ponds and temporary water bodies in northern India, feeds on cladocerans, rotifers, ciliates and when present, on mosquito larvae also. We studied in the laboratory the prey consumption rates of the copepod on first and fourth instar larvae of two species of mosquito (Anopheles stephensi and Culex quinquefasciatus) in relation to their density. We also studied its prey selectivity with mosquito larvae in the presence of an alternate prey (the cladocerans-either Moina macrocopa or Ceriodaphnia cornuta) in different proportions. With either mosquito species, the copepod actively selected Instar-I larvae, avoiding the Instar-IV larvae, and with either instar, selected Anopheles stephensi over Culex quinquefasciatus. When prey choice included the cladoceran as an alternate prey, the copepod selected the cladoceran only when the other prey was Instar-IV mosquito larvae. Our results point to the potential and promise of M. thermocyclopoides as a biological agent for controlling larval populations of vectorially important mosquito species.

  19. Application of X-ray imaging techniques for studying the morphology of malaria-transmitting mosquitoes

    International Nuclear Information System (INIS)

    The X-ray phase contrast tomography technique was applied to examine the morphology of malaria transmitting mosquitoes in support of the development of the sterile insect technique (SIT). The aim of the experiment was to detect possible damage induced by the sample preparation procedures, to perform X-ray phase-contrast imaging on freshly prepared (not fixed) and live mosquito species, and to test the new beam line set up, which was not yet fully commissioned at the time of the experiment. The ability to perform X-ray phase-contrast imaging of live mosquito specimens was confirmed. The collected still images provided data on a relatively large population of mosquitoes. The CT data were very useful to compare selected mosquito species. They confirmed that the sample preparation procedures are critical for examining the morphological details. The procedures must be further optimized in order to stabilize the sample without inducing significant damage. The most interesting results should be obtained with the high-resolution (? 0.5 micrometer) set up using the FReloN camera to be commissioned at the TOPO beam line in the 3rd quarter of 2007. If there are differences between the control and irradiated populations of mosquitoes they should show up first at the tissue level. Using the high-resolution setup it should be possible to detect such differences, if present

  20. The behaviour of mosquitoes in relation to humans under holed bednets: the evidence from experimental huts

    Scientific Electronic Library Online (English)

    Seth R, Irish.

    2014-11-01

    Full Text Available The physical integrity of bednets is a concern of national malaria control programs, as it is a key factor in determining the rate of replacement of bednets. It is largely assumed that increased numbers of holes will result in a loss of protection of sleepers from potentially infective bites. Experi [...] mental hut studies are valuable in understanding mosquito behaviour indoors, particularly as it relates to blood feeding and mortality. This review summarises findings from experimental hut studies, focusing on two issues: (i) the effect of different numbers or sizes of holes in bednets and (ii) feeding behaviour and mortality with holed nets as compared with unholed nets. As might be expected, increasing numbers and area of holes resulted in increased blood feeding by mosquitoes on sleepers. However, the presence of holes did not generally have a large effect on the mortality of mosquitoes. Successfully entering a holed mosquito net does not necessarily mean that mosquitoes spend less time in contact with the net, which could explain the lack in differences in mortality. Further behavioural studies are necessary to understand mosquito behaviour around nets and the importance of holed nets on malaria transmission.

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

    OpenAIRE

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

    2009-01-01

    Abstract 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...

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

    OpenAIRE

    Ageep, T. B.; Cox, J.; Hassan, M. M.; Knols, B. G. J.; Benedict, M. Q.; Malcolm, C. A.; Babiker, A.; El Sayed, B. 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 carrie...

  3. Control of pyrethroid and DDT-resistant Anopheles gambiae by application of indoor residual spraying or mosquito nets treated with a long-lasting organophosphate insecticide, chlorpyrifos-methyl

    Directory of Open Access Journals (Sweden)

    Chabi Joseph

    2010-02-01

    Full Text Available Abstract Background Scaling up of long-lasting insecticidal nets (LLINs and indoor residual spraying (IRS with support from the Global Fund and President's Malaria Initiative is providing increased opportunities for malaria control in Africa. The most cost-effective and longest-lasting residual insecticide DDT is also the most environmentally persistent. Alternative residual insecticides exist, but are too short-lived or too expensive to sustain. Dow Agrosciences have developed a microencapsulated formulation (CS of the organophosphate chlorpyrifos methyl as a cost-effective, long-lasting alternative to DDT. Methods Chlorpyrifos methyl CS was tested as an IRS or ITN treatment in experimental huts in an area of Benin where Anopheles gambiae and Culex quinquefasiactus are resistant to pyrethroids, but susceptible to organophosphates. Efficacy and residual activity was compared to that of DDT and the pyrethroid lambdacyalothrin. Results IRS with chlorpyrifos methyl killed 95% of An. gambiae that entered the hut as compared to 31% with lambdacyhalothrin and 50% with DDT. Control of Cx. quinquefasciatus showed a similar trend; although the level of mortality with chlorpyrifos methyl was lower (66% it was still much higher than for DDT (14% or pyrethroid (15% treatments. Nets impregnated with lambdacyhalothrin were compromized by resistance, killing only 30% of An. gambiae and 8% of Cx. quinquefasciatus. Nets impregnated with chlorpyrifos methyl killed more (45% of An gambiae and 15% of Cx. quinquefasciatus, but its activity on netting was of short duration. Contact bioassays on the sprayed cement-sand walls over the nine months of monitoring showed no loss of activity of chlorpyrifos methyl, whereas lambdacyhalothrin and DDT lost activity within a few months of spraying. Conclusion As an IRS treatment against pyrethroid resistant mosquitoes chlorpyrifos methyl CS outperformed DDT and lambdacyhalothrin. In IRS campaigns, chlorpyrifos methyl CS should show higher, more-sustained levels of malaria transmission control than conventional formulations of DDT or pyrethroids. The remarkable residual activity indicates that cost-effective alternatives to DDT are feasible through modern formulation technology.

  4. 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.

    Science.gov (United States)

    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...

  5. A new resting trap to sample fungus-infected mosquitoes, and the pathogenicity of Lecanicillium muscarium to culicid adults.

    Science.gov (United States)

    Luz, Christian; Mnyone, Ladslaus L; Sangusangu, Robert; Lyimo, Issa N; Rocha, Luiz F N; Humber, Richard A; Russell, Tanya L

    2010-10-01

    Some soil-dwelling entomopathogenic fungi that are widely used in pest control are also able to reduce the survival of adult mosquito vectors under laboratory conditions. However, there is still little information about the naturally occurring fungal pathogens affecting culicid mosquitoes. As such, we hypothesized that fungi that already kill mosquitoes in realistic domestic environments could be effective against these vectors in human habitations. A simple, inexpensive, handmade, cylindrical kiln-fired clay pot (30 cm height, 24 cm inner diameter, 0.8-1cm wall thickness) was modified into a trapping device for resting adult mosquitoes and to sample fungus-infected moribund and dead individuals. The entomopathogenic fungus Lecanicillium muscarium was isolated from a dead culicid mosquito collected with this trap in southeastern Tanzania. This isolate is the first L. muscarium reported to occur naturally on adult culicids in Tanzania and was found to be pathogenic also to adults of Aedes aegypti, Anopheles arabiensis and Culex quinquefasciatus under laboratory conditions. The trapping device confirmed its efficacy to sample mosquito-specific fungi in domestic locations and that the isolated fungus might have potential for mosquito control. PMID:20452324

  6. Laboratory evaluation of predation on mosquito larvae by Australian mangrove fish.

    Science.gov (United States)

    Griffin, Lachlan

    2014-06-01

    A series of laboratory experiments compared predation rates of three native eastern Australian mangrove fish species (Psuedomugil signifer, Hyseleotris galii, Pseudogobius sp.) and the exotic Gambusia holbrooki on 2nd and 4th instar Aedes vigilax larvae, in order to determine their potential as mosquito control agents in mangrove forests. All four species preyed on significant numbers of both 2nd and 4th instar larvae. All showed a similar pattern of larval consumption, gorging on larvae in the first hour of each experiment, before reducing to a relatively constant background feeding rate. Gambusia holbrooki showed the highest larval consumption rates, but is unsuitable as a mosquito control agent due to it being an exotic pest species in Australia. Of the three native species, P. signifer showed the greatest potential as a mosquito control agent, having consumption rates comparable to G. holbrooki, and was the only species that did not show a significant reduction in larval consumption in the night experiments. PMID:24820573

  7. Malaria Parasites Produce Volatile Mosquito Attractants

    Science.gov (United States)

    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

  8. Can mosquitoes fly in the rain?

    CERN Document Server

    Dickerson, Andrew; Madhavan, Nihar; Hu, David

    2011-01-01

    Collisions with raindrops are one of many obstacles insects face during flight. In this fluid dynamics video, we present a series of high-speed films of impacts between mosquitoes and raindrops. We also present drop impacts upon insect mimics, which are unsupported styrofoam balls of the same mass as mosquitoes. High-speed videography and particle tracking during collision are employed to determine the insect position versus time. We determine the magnitude of acceleration by considering the momentum transfer and impact duration. Experiments with live mosquitoes indicate a surprising ability to quickly recover flight post-collision, despite accelerations of 30-300 gravities over durations of 1 ms.

  9. Susceptibility of adult mosquitoes to insecticides in aqueous sucrose baits.

    Science.gov (United States)

    Allan, Sandra A

    2011-06-01

    Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence and intermittently during their lives. Development of toxic baits focusing on this carbohydrate-seeking behavior may potentially contribute to localized control. In the present study, ten insecticides were fed to female Culex quinquefasciatus, Anopheles quadrimaculatus, and Aedes taeniorhynchus in a 10% sucrose solution. Active ingredients representative of five classes of insecticides (pyrethroids, phenylpyroles, pyrroles, neonicotinoids, and macrocyclic lactones) were selected for comparison with commercial formulations used to facilitate incorporation of active ingredients into aqueous sucrose solutions. Sucrose as a phagostimulant significantly enhanced mortality to toxicants. In general, the most effective active ingredients were fipronil, deltamethrin and imidacloprid, followed by spinosad, thiamethoxam, bifenthrin, permethrin, and cyfluthrin. The least effective ingredients were chlorfenapyr and ivermectin. For some of the ingredients tested, Cx. quinquefasciatus was the least susceptible species. One-day-old male Cx. quinquefasciatus were more susceptible than females; however, no differences existed between one- and seven-day-old mosquitoes. There were no differences in susceptibility between unfed and gravid ten-day-old female Cx. quinquefasciatus to bifenthrin. In conclusion, several pesticides from different classes of compounds have potential for use in development of toxic baits for mosquitoes. PMID:21635642

  10. Evolution of mosquito-based arbovirus surveillance systems in Australia.

    Science.gov (United States)

    van den Hurk, Andrew F; Hall-Mendelin, Sonja; Johansen, Cheryl A; Warrilow, David; Ritchie, Scott A

    2012-01-01

    Control of arboviral disease is dependent on the sensitive and timely detection of elevated virus activity or the identification of emergent or exotic viruses. The emergence of Japanese encephalitis virus (JEV) in northern Australia revealed numerous problems with performing arbovirus surveillance in remote locations. A sentinel pig programme detected JEV activity, although there were a number of financial, logistical, diagnostic and ethical limitations. A system was developed which detected viral RNA in mosquitoes collected by solar or propane powered CO?-baited traps. However, this method was hampered by trap-component malfunction, microbial contamination and large mosquito numbers which overwhelmed diagnostic capabilities. A novel approach involves allowing mosquitoes within a box trap to probe a sugar-baited nucleic-acid preservation card that is processed for expectorated arboviruses. In a longitudinal field trial, both Ross River and Barmah Forest viruses were detected numerous times from multiple traps over different weeks. Further refinements, including the development of unpowered traps and use of yeast-generated CO?, could enhance the applicability of this system to remote locations. New diagnostic technology, such as next generation sequencing and biosensors, will increase the capacity for recognizing emergent or exotic viruses, while cloud computing platforms will facilitate rapid dissemination of data. PMID:22505808

  11. Fog spontaneously folds mosquito wings

    Science.gov (United States)

    Dickerson, Andrew K.; Liu, Xing; Zhu, Ting; Hu, David L.

    2015-02-01

    The flexibility of insect wings confers aerodynamic benefits, but can also present a hazard if exposed to fog or dew. Fog can cause water to accumulate on wings, bending them into tight taco shapes and rendering them useless for flight. In this combined experimental and theoretical study, we use high-speed video to film the spontaneous folding of isolated mosquito wings due to the evaporation of a water drop. We predict shapes of the deformed wing using two-dimensional elastica theory, considering both surface tension and Laplace pressure. We also recommend fold-resistant geometries for the wings of flapping micro-aerial vehicles. Our work reveals the mechanism of insect wing folding and provides a framework for further study of capillarity-driven folding in both natural and biomimetic systems at small scales.

  12. Slow Death by Many Mosquito Bites

    CERN Document Server

    Redner, S

    2014-01-01

    We study the dynamics of a single diffusing particle (a "man") with diffusivity $D_M$ that is attacked by another diffusing particle (a "mosquito") with fixed diffusivity $D_m$. Each time the mosquito meets and bites the man, the diffusivity of the man is reduced by a fixed amount, while the diffusivity of the mosquito is unchanged. The mosquito is also displaced by a small distance $\\pm a$ with respect to the man after each encounter. The man is defined as dead when $D_M$ reaches zero. At the moment when the man dies, his probability distribution of displacements $x$ is given by a Cauchy form, which asymptotically decays as $x^{-2}$, while the distribution of times $t$ when the man dies asymptotically decays as $t^{-3/2}$, which has the same form as the one-dimensional first-passage probability.

  13. Riqueza de especies de mosquitos, distribución y sitios de cría en el municipio Boyeros / Wealth of mosquito species, their distribution and breeding sites in Boyeros municipality

    Scientific Electronic Library Online (English)

    Vivian, Valdés Miró; Mayra, Reyes Arencibia; María del Carmen, Marquetti Fernández; Raúl, González Broche.

    2013-04-01

    Full Text Available Introducción: la identificación de las especies de mosquitos en cada municipio en Cuba forma parte del Programa de Control de Aedes aegypti y Aedes albopictus, lo cual representa un factor importante en la aparición de eventos epidemiológicos o zoonóticos que involucren estos insectos. Objetivo: con [...] ocer la riqueza de especies de mosquitos y su distribución en el municipio Boyeros. Métodos: el trabajo se desarrolló en el municipio Boyeros, La Habana en el período 1982-2011. Las muestras de mosquitos se colectaron por los trabajadores del programa de control de Aedes aegypti y Aedes albopictus. Resultados: la riqueza de especies de mosquitos fue de 35, de estas 10 se encuentran distribuidas en todas las áreas del municipio. El área con mayor riqueza de especie fue Mulgoba seguida por Wajay, y la de menor correspondió a Boyeros. Se colectaron 8 especies en depósitos artificiales y naturales como hueco de árboles; mientras que 22 se colectaron en reservorios de aguas naturales, lagunas de oxidación, zanjas, arroyos, lagunatos y ríos. Del total de especies, 5 solo fueron colectadas en estadio adulto. Conclusiones: la emergencia y reemergencia de algunas enfermedades transmitidas por mosquitos es uno de los aspectos que más seguimiento tiene en estos momentos en el continente americano, por lo que conocer la fauna de mosquitos del municipio así como su distribución es importante. De presentarse algún brote o epidemia que involucren a estos insectos obligaría a establecer las estrategias de control, para evitar la propagación de enfermedades de transmisión vectorial. Abstract in english Introduction: the identification of mosquito species in each municipality of Cuba is part of the Aedes aegypti and Aedes albopictus control program. This is an important factor in the occurrence of epidemiological or zoonotic events involving these insects. Objective: to identify the wealth of mosqu [...] ito species and their distribution in Boyeros municipality. Methods: the study was developed in Boyeros municipality from 1982 to 2011. The mosquito samples were taken by the Aedes aegypti and Aedes albopictus control program workers. Results: the wealth of mosquito species includes 35 species of which 10 are distributed in all the areas of the municipality. The area with the largest wealth of species was Mulgoba, followed by Wajay, and the smallest one was found in Boyeros. Eight species were collected in artificial and natural reservoirs such as tree holes, whereas 22 were observed in natural water reservoirs, oxidation lagoons, ditches, streams and rivers. Of all the species, just 5 were collected in their adult stage. Conclusions: emergency and reemergence of some mosquito-borne diseases is one of the more watched aspects at this time in the American continent, thus the mosquito fauna of the municipality and its distribution is fundamental. If any outbreak or epidemic involving these insects occurs, it would be compulsory to set up control strategies to prevent the spread of vector-borne diseases.

  14. Señales físico químicas involucradas en la búsqueda de hospederos y en la inducción de picadura por mosquitos

    Directory of Open Access Journals (Sweden)

    Torres-Estrada José Luis

    2003-01-01

    Full Text Available Las hembras de los mosquitos vectores de enfermedades utilizan señales físicas y químicas para localizar su fuente de alimentación sanguínea en hospederos vertebrados. Los mosquitos zoofílicos responden preferentemente al CO2 y al octenol liberados en la respiración y excreciones, mientras que los mosquitos antropofílicos responden al ácido láctico y a una variedad de compuestos del sudor. Estos compuestos son modificados por microrganismos saprófitos de las glándulas sebáceas de la piel. Otros factores presentes en las viviendas contribuyen a la integración de microsistemas constituidos por olores característicos, que explican los diferentes niveles de atracción de mosquitos y la focalización de la transmisión del paludismo a una porción de casas en localidades de áreas endémicas. La identificación de estos atrayentes químicos y sus moléculas receptoras en mosquitos puede ser utilizada como complemento de nuevos métodos para la vigilancia epidemiológica, para atraer a los mosquitos a trampas de colecta o para incrementar su contacto con insecticidas usados en su control, así como en la manipulación genética para desviar las picaduras de los mosquitos hacia otros hospederos vertebrados.

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

    Directory of Open Access Journals (Sweden)

    Malcolm Colin A

    2009-06-01

    Full Text Available Abstract 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.

  16. Can mosquitoes fly in the rain?

    OpenAIRE

    Dickerson, Andrew; Shankles, Peter; Madhavan, Nihar; Hu, David

    2011-01-01

    Collisions with raindrops are one of many obstacles insects face during flight. In this fluid dynamics video, we present a series of high-speed films of impacts between mosquitoes and raindrops. We also present drop impacts upon insect mimics, which are unsupported styrofoam balls of the same mass as mosquitoes. High-speed videography and particle tracking during collision are employed to determine the insect position versus time. We determine the magnitude of acceleration b...

  17. Aedes Mosquito Species in Western Saudi Arabia

    OpenAIRE

    Alikhan, Masroor; Ghamdi, Khalid Al; Mahyoub, Jazem Abdullah

    2014-01-01

    The Aedes Meigen (Diptera: Culicidae) mosquito species populations in the western region of Saudi Arabia, especially in and around Jeddah, are increasing, therefore increasing susceptibility of humans to the dengue virus. An extensive survey was carried out for one year, and four species were identified with the help of different pictorial keys available. The identification was based on morphological characteristics of adult female Aedes mosquitoes.

  18. Repellent properties of Cardiospermum halicacabum Linn. (Family: Sapindaceae) plant leaf extracts against three important vector mosquitoes

    Science.gov (United States)

    Govindarajan, M; Sivakumar, R

    2012-01-01

    Objective To determine repellent activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Cardiospermum halicacabum (C. halicacabum) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi). Methods Evaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved female mosquitoes of three mosquito species and were assayed in the laboratory condition by using the protocol of WHO 2005; The plant leaf crude extracts of C. halicacabum was applied at 1.0, 2.5, and 5.0 mg/cm2 separately in the exposed area of the fore arm. Only ethanol served as control. Results In this observation, the plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity was dependent on the strength of the plant extracts. The tested plant crude extracts had exerted promising repellent against all the three mosquitoes. Conclusions From the results it can be concluded the crude extract of C. halicacabum was potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes. PMID:23569979

  19. Factors influencing the predation rates of Anisops breddini (Hemiptera: Notonectidae feeding on mosquito larvae

    Directory of Open Access Journals (Sweden)

    R. Weterings

    2014-12-01

    Full Text Available Notonectidae are a family of water bugs that are known to be important predators of mosquito larvae and have great potential in the biological control of vector mosquitoes. An experiment was conducted to assess mosquito larvae predation by Anisops breddini, a species common to Southeast Asia. The predation rates were recorded in context of prey density, predator density, predator size and prey type. Predation rates were strongly affected by prey type and less by prey density and predator density. They ranged between 1.2 prey items per day for pupae of Aedes aegeypti and Armigeres moultoni to 5.9 for Ae. aegypti larvae. Compared with studies on other Notonectidae species, the predation rates appear low, which is probably caused by the relative small size of the specimens used in this study. An. breddini is very common in the region and often found in urban areas; therefore, the species has potential as a biological control agent.

  20. Repelentes electrónicos contra mosquitos: propaganda y realidad

    Directory of Open Access Journals (Sweden)

    Frank Coro

    1998-08-01

    Full Text Available Se presenta una revisión bibliográfica acerca del uso de dispositivos electroacústicos con supuesta acción repelente sobre las hembras de diferentes especies de mosquitos hematófagos. Se dan 15 referencias directas y 2 indirectas, en todas se concluye que estos dispositivos no protegen a quienes los portan de las picadas de los mosquitos. Se dan los nombres de 9 de los dispositivos probados, así como de 16 de las principales especies de mosquitos presentes en las pruebas de campo. Estas pruebas de campo se han realizado en condiciones ecológicas muy diferentes, que van desde alaska hasta el África Ecuatorial. También se menciona el efecto potencialmente dañino al hombre de los dispositivos que emiten frecuencias a alta intensidad.A bibliographic review about the use of electroacustic devices with a supposed repellent action on the females of different species of hematophagous mosquitoes is presented. 15 direct references and 2 indirect ones are given, in which it is concluded that these devices do not protect those who have them from the stings of mosquitoes. The names of 9 of the tested devices as well as of 16 of the main species of mosquitoes present in the field tests are mentioned. These tests have been carried out in very different ecological conditions from Alaska to Equatorial Africa. It is also stressed that the high intensity ultrasonic frequencies emitted by these devices produces a potentially harmful effect on man.

  1. Expression of mosquito active toxin genes by a Colombian native strain of the gram-negative bacterium Asticcacaulis excentricus

    OpenAIRE

    Romero Magally; Gil Flor M; Orduz Sergio

    2001-01-01

    Mosquito control with biological insecticides, such as Bacillus sp. toxins, has been used widely in many countries. However, rapid sedimentation away from the mosquito larvae feeding zone causes a low residual effect. In order to overcome this problem, it has been proposed to clone the Bacillus toxin genes in aquatic bacteria which are able to live in the upper part of the water column. Two strains of Asticcacaulis excentricus were chosen to introduce the B. sphaericus binary toxin gene and B...

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

    Science.gov (United States)

    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

  3. Population interactions between Culex vishnui mosquitoes and their natural enemies in Pondicherry, India.

    Science.gov (United States)

    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

  4. ATon, abundant novel nonautonomous mobile genetic elements in yellow fever mosquito (Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Yang Guojun

    2012-06-01

    Full Text Available Abstract Background Mosquitoes are important pathogen vectors affecting human and other animals. Studies on genetic control of mosquito mediated disease transmission gained traction recently due to mosquito transgenesis technology. Active transposons are considered valuable tools to propagate pathogen resistance transgenes among mosquitoes, rendering the whole population recalcitrant to diseases. A major hurdle in this approach is the inefficient remobilization activity after the integration of heterologous transposon vectors bearing transgenes into chromosomes. Therefore, endogenous active transposons in mosquito genomes are highly desirable. Results Starting with the transposable element database of the yellow fever mosquito Aedes aegypti genome, detailed analyses of the members of each TE family were performed to identify sequences with multiple identical copies, an indicator of their latest or current transposition activity. Among a dozen of potentially active TE families, two DNA elements (TF000728 and TF000742 in TEfam are short and nonautonomous. Close inspection of the elements revealed that these two families were previously mis-categorized and, unlike other known TEs, insert specifically at dinucleotide “AT”. These two families were therefore designated as ATon-I and ATon-II. ATon-I has a total copy number of 294, among which three elements have more than 10 identical copies (146, 61 and 17. ATon-II has a total copy number of 317, among which three elements have more than 10 identical copies (84, 15 and 12. Genome wide searches revealed additional 24 ATon families in A. aegypti genome with nearly 6500 copies in total. Transposon display analysis of ATon-1 family using different A. aegypti strains suggests that the elements are similarly abundant in the tested mosquito strains. Conclusion ATons are novel mobile genetic elements bearing terminal inverted repeats and insert specifically at dinucleotide “AT”. Five ATon families contain elements existing at more than 10 identical copies, suggesting very recent or current transposition activity. A total of 24 new TE families with nearly 6000 copies were identified in this study.

  5. Preliminary evaluation of mosquito larvicidal efficacy of plant extracts

    Directory of Open Access Journals (Sweden)

    N.G. Das, D. Goswami & B. Rabha

    2007-06-01

    Full Text Available Mosquitoes are the most important single group ofinsects in terms of public health importance, whichtransmit a number of diseases, such as malaria, filariasis,dengue, Japanese encephalitis, etc. causing millionsof deaths every year. Repeated use of syntheticinsecticides for mosquito control has disrupted naturalbiological control systems and led to resurgencesin mosquito populations. It has also resulted in thedevelopment of resistance1, undesirable effects onnon-target organisms and fostered environmental andhuman health concern2, which initiated a search foralternative control measures. Plants are considered asa rich source of bioactive chemicals3 and they may bean alternative source of mosquito control agents.Natural products of plant origin with insecticidalproperties have been tried in the recent past for controlof variety of insect pests and vectors. Essentialoils of leaf and bark of Cryptomeria japonica demonstratedhigh larvicidal activity against Aedesaegypti (Diptera: Culicidae larvae4. Insecticidalactivity of plant essential oils has been well-describedby Isman5. Azadiractin, the active ingredient of neemhas long been recognised for its mosquito larvicidalcapability. The extracts of Murraya koenigii, Coriandrumsativam, Ferula asafetida and Trigonella foenumgraceum were found to be effective and showedencouraging results against Ae. aegypti6 and Culex(Diptera: Culicidae mosquito larvae7. It is also reportedthat many compounds with insecticidal potentialhave been isolated from the genus Piper—Pipercide,isolated from Piper negrum (black piper hasbeen found to be just as active against adjuki beanweevils as the pyrethroides8. Phytochemicals derivedfrom plant sources can act as larvicide, insect growthregulators, repellent and ovipositor attractant andhave different activities observed by many researchers9–11. However, insecticides of plant origin havebeen extensively used on agricultural pests and to avery limited extent, against insect vectors of publichealth importance.Northeastern region of India is considered as a majorbiodiversity hot spot. The eastern Himalayas range,which extends all through the northern border ofAssam, is a rich treasure house of many promisingmedicinal and aromatic plants. In the present communication,an attempt has been made to evaluate themosquito larvicidal efficacy of methanol and ethanolextracts of different parts of five indigenous plantsagainst Ae. albopictus (Diptera: Culicidae and Culexquinquefasciatus larvae in laboratory conditions.Plant materials were collected from the foothill forestsof Sonitpur district, Assam bordering ArunachalPradesh during April and May 2005. They were segregatedas leaf, stem, bark, root and fruit/pericarp andair-dried in a shady place. Dried materials wereground in a table model grinder. The ground plant materialswere dipped in solvents (methanol and ethanolShort Research Communications146 J VECT BORNE DIS 44, JUNE 2007in tightly capped jars separately for 48 h. The solventsalong with extracts were drained out, filtered andsemisolid extracts were obtained in vacuum usingrotary evaporator. The semisolid extracts were lyophilisedto obtain solid extracts. Stock solutions of desiredconcentration were prepared in distilled waterusing 1 ppm teepol as emulsifying agent and subsequentdilutions were made as per requirement. Larvicidalbioassay was carried out as per standard WHOtechniques in 500 ml glass beakers containing 250 mlof water and 25 numbers of late III or early IV instarmosquito larvae for various concentrations. Threedifferent concentrations of each extract were tried outat a time with six replicates. One control was kept witheach set of experiment and mortality was recordedafter 24 h. Five sets of experiments were conductedfor each extract. Tests were carried out under controlledlaboratory conditions (temperature 27 ± 2oCagainst laboratory reared Ae. albopictus and Cx. quinquefasciatus(Diptera: Culicidae larvae. Values obtainedwere subjected to log probit regression analysisto obtain LC50 and LC90 values with 95% confidencel

  6. On the analysis of effectiveness in mass application of mosquito repellent for dengue disease prevention

    Science.gov (United States)

    Aldila, D.; Soewono, E.; Nuraini, N.

    2012-05-01

    Dengue disease has been known as one of dangerous vector-borne diseases and become serious threat in many tropical countries. With no vaccine and antiviral available until nowadays, and frequent appearance of extraordinary dengue outbreaks, many governments are forced to declare national problem for dengue. At this moment, the only method available to prevent dengue disease transmission is to combat the disease-carrying mosquitoes as well as to reduce the contact between human and mosquitoes. The fast growing dengue transmission in many countries in recent years indicates that the mosquito control programs are far from successful. The use of mosquito repellent is one possible instrument which could be used as an effective mass treatment to prevent the dengue outbreak during endemic period. Here in this paper a Susceptible-Infectious-Recovered (S-I-R) dengue transmission model with repellent mass treatment is being applied to portions of children and adult compartments. Analysis of the basic reproductive ratio (Ro) of the model is done. It is shown, with reasonable choices of portions of treated children and adults, in combination with reduction of mosquito population, the basic reproductive ratio can be significantly reduced and occurrence of endemic can be avoided. Numerical simulations are shown for various treatment scenarios.

  7. Mosquito (Diptera: Culicidae) repellency field tests of essential oils from plants traditionally used in Laos.

    Science.gov (United States)

    Vongsombath, Chanda; Pålsson, Katinka; Björk, Lars; Borg-Karlson, Anna-Karin; Jaenson, Thomas G T

    2012-11-01

    Essential oils of Hyptis suaveolens (Lamiaceae), Croton roxburghii (Euphorbiaceae), and Litsea cubeba (Lauraceae) were tested in the field near Vientiane city, Lao PDR, on humans for repellent activity against mosquitoes. Landing mosquitoes were collected and later identified. The most abundant mosquitoes captured belonged to the genera Armigeres, Culex, and Aedes. All the plant oils tested at concentrations of 1.7 microg/cm(2), 3.3 microg/cm(2), and 6.3 microg/cm(2) were significantly more mosquito repellent than the negative control. Croton oil was significantly repellent against mosquitoes of the three genera at the highest (6.3 microg/cm(2)) concentration tested. Litsea oil was significantly repellent against Armigeres at all (1.7 microg/cm(2), 3.3 microg/cm(2), and 6.3 microg/cm(2)) concentrations tested. Hyptis oil was significantly repellent against Armigeres at 3.3 microg/cm(2) and 6.3 microg/cm(2) and against Culex at 1.7 microg/cm(2) and 6.3 microg/cm(2). The oils were analyzed for chemical content of volatiles, mainly terpenes. Main constituents were beta-pinene, sabinene, and 1,8-cineol from oils of the green parts of H. suaveolens; alpha-pinene, beta-pinene, and alpha-phellandrene from fresh bark of C. roxburghii; and alpha-pinene, beta-phellandrene, sabinene, and 1,8-cineol from fresh fruits of L. cubeba. PMID:23270168

  8. Load-bearing ability of the mosquito tarsus on water surfaces arising from its flexibility

    Directory of Open Access Journals (Sweden)

    X. Q. Kong

    2015-03-01

    Full Text Available Mosquitoes possess a remarkable ability to stand effortlessly and walk freely on water surfaces because their six legs provide a large force to support the body weight. This study is focused on the role of the tarsus (the distal segment of the mosquito leg because it was observed that normally only the tarsi make contact with water. The maximum value of the supporting force of the tarsus (6 mm long in contact with water is estimated as 492 ± 5 ?N, nearly 20 times the body weight of the mosquito, whereas the value for the whole leg (11 mm is about 23 times the body weight. We demonstrate that the huge force provided by the tarsus originates from its flexibility, which ensures that the leg does not easily pierce the water. Adjustment of the initial stepping angle of the tarsus assists the mosquito to control the supporting force. These findings help to illustrate how mosquitoes stand or walk on water with only their tarsi in nearly horizontal contact with the water surface. Besides enhancing our understanding of mechanisms underlying “walking on water” by semi-aquatic insects, these investigations could provide inspiration for the biomimetic design of miniature robotics.

  9. An insight into the sialotranscriptome of the West Nile mosquito vector, Culex tarsalis

    Directory of Open Access Journals (Sweden)

    Olson Kenneth E

    2010-01-01

    Full Text Available Abstract Background Saliva of adult female mosquitoes help sugar and blood feeding by providing enzymes and polypeptides that help sugar digestion, control microbial growth and counteract their vertebrate host hemostasis and inflammation. Mosquito saliva also potentiates the transmission of vector borne pathogens, including arboviruses. Culex tarsalis is a bird feeding mosquito vector of West Nile Virus closely related to C. quinquefasciatus, a mosquito relatively recently adapted to feed on humans, and the only mosquito of the genus Culex to have its sialotranscriptome so far described. Results A total of 1,753 clones randomly selected from an adult female C. tarsalis salivary glands (SG cDNA library were sequenced and used to assemble a database that yielded 809 clusters of related sequences, 675 of which were singletons. Primer extension experiments were performed in selected clones to further extend sequence coverage, allowing for the identification of 283 protein sequences, 80 of which code for putative secreted proteins. Conclusion Comparison of the C. tarsalis sialotranscriptome with that of C. quinquefasciatus reveals accelerated evolution of salivary proteins as compared to housekeeping proteins. The average amino acid identity among salivary proteins is 70.1%, while that for housekeeping proteins is 91.2% (P Aedes genus have been identified in C. tarsalis. Interestingly, a protein family so far unique to C. quinquefasciatus, with 30 genes, is also found in C. tarsalis, indicating it was not a specific C. quinquefasciatus acquisition in its evolution to optimize mammal blood feeding.

  10. COMPARATIVE ASSESSMENT OF MOSQUITO BIOCONTROL EFFICIENCY BETWEEN GUPPY (POECILIA RETICULATA AND PANCHAX MINNOW (APLOCHEILUS PANCHAX

    Directory of Open Access Journals (Sweden)

    Sandipan Gupta and Samir Banerjee

    2013-01-01

    Full Text Available The present work was designed to compare the mosquito biocontrol efficiency of guppy and panchax minnow, the two popular fish species which so far have been used for mosquito biocontrol here in India. Study of the predation efficiency in relation to fish size and larval size has revealed significant better predation efficiency of panchax minnow over guppy in all size groups except for pupae in small size group fishes. Study of the comparative predation efficiency under vegetative cover has revealed significant (P<0.01 higher predation efficiency for panchax minnow over guppy. Study of the comparative predation efficiency under different depth of water has revealed superior predation efficiency of guppy under shallow water depth whereas panchax minnow has shown significantly better predation efficiency with increasing water depth. So, panchax minnow is a better mosquito biocontrol agent in waterbodies with vegetative covering and in comparatively deep water bodies whereas guppy can be used for mosquito control in very shallow water depth. But overall the study has depicted the superiority of panchax minnow over guppy as mosquito biocontrol agent.

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

    Directory of Open Access Journals (Sweden)

    Hati A K

    1995-01-01

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

  12. Load-bearing ability of the mosquito tarsus on water surfaces arising from its flexibility

    Science.gov (United States)

    Kong, X. Q.; Liu, J. L.; Zhang, W. J.; Qu, Y. D.

    2015-03-01

    Mosquitoes possess a remarkable ability to stand effortlessly and walk freely on water surfaces because their six legs provide a large force to support the body weight. This study is focused on the role of the tarsus (the distal segment of the mosquito leg) because it was observed that normally only the tarsi make contact with water. The maximum value of the supporting force of the tarsus (6 mm long) in contact with water is estimated as 492 ± 5 ?N, nearly 20 times the body weight of the mosquito, whereas the value for the whole leg (11 mm) is about 23 times the body weight. We demonstrate that the huge force provided by the tarsus originates from its flexibility, which ensures that the leg does not easily pierce the water. Adjustment of the initial stepping angle of the tarsus assists the mosquito to control the supporting force. These findings help to illustrate how mosquitoes stand or walk on water with only their tarsi in nearly horizontal contact with the water surface. Besides enhancing our understanding of mechanisms underlying "walking on water" by semi-aquatic insects, these investigations could provide inspiration for the biomimetic design of miniature robotics.

  13. Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum

    Directory of Open Access Journals (Sweden)

    Rivero Ana

    2010-12-01

    Full Text Available Abstract Background The control of most vectors of malaria is threatened by the spread of insecticide resistance. One factor that has been hitherto largely overlooked is the potential effects of insecticide resistance on the ability of mosquitoes to transmit malaria: are insecticide-resistant mosquitoes as good vectors of Plasmodium as susceptible ones? The drastic physiological changes that accompany the evolution of insecticide resistance may indeed alter the ability of vectors to transmit diseases, a possibility that, if confirmed, could have major epidemiological consequences. Methods Using a novel experimental system consisting of the avian malaria parasite (Plasmodium relictum and its natural vector (the mosquito Culex pipiens, two of the most common mechanisms of insecticide resistance (esterase overproduction and acetylcholinesterase modification were investigated for their effect on mosquito infection rate and parasite burden. For this purpose two types of experiments were carried out using (i insecticide-resistant and susceptible laboratory isogenic lines of Cx. pipiens and (ii wild Cx. pipiens collected from a population where insecticide resistant and susceptible mosquitoes coexist in sympatry. Results The isogenic line and wild-caught mosquito experiments were highly consistent in showing no effect of either esterase overproduction or of acetylcholinesterase modification on either the infection rate or on the oocyst burden of mosquitoes. The only determinant of these traits was blood meal size, which was similar across the different insecticide resistant categories in both experiments. Conclusions Insecticide resistance was found to have no effect on Plasmodium development within the mosquito. This is the first time this question has been addressed using a natural mosquito-Plasmodium combination, while taking care to standardize the genetic background against which the insecticide resistance genes operate. Infection rate and oocyst burden are but two of the factors that determine the vectorial capacity of mosquitoes. Other key determinants of parasite transmission, such as mosquito longevity and behaviour, or the parasite's incubation time, need to be investigated before concluding on whether insecticide resistance influences the ability of mosquitoes to transmit malaria.

  14. Into the environment of mosquito-borne disease: A spatial analysis of vector distribution using traditional and remotely sensed methods

    Science.gov (United States)

    Brown, Heidi E.

    Spatially explicit information is increasingly available for infectious disease modeling. However, such information is reluctantly or inappropriately incorporated. My dissertation research uses spatially explicit data to assess relationships between landscape and mosquito species distribution and discusses challenges regarding accurate predictive risk modeling. The goal of my research is to use remotely sensed environmental information and spatial statistical methods to better understand mosquito-borne disease epidemiology for improvement of public health responses. In addition to reviewing the progress of spatial infectious disease modeling, I present four research projects. I begin by evaluating the biases in surveillance data and build up to predictive modeling of mosquito species presence. In the first study I explore how mosquito surveillance trap types influence estimations of mosquito populations. Then. I use county-based human surveillance data and landscape variables to identify risk factors for West Nile virus disease. The third study uses satellite-based vegetation indices to identify spatial variation among West Nile virus vectors in an urban area and relates the variability to virus transmission dynamics. Finally, I explore how information from three satellite sensors of differing spatial and spectral resolution can be used to identify and distinguish mosquito habitat across central Connecticut wetlands. Analyses presented here constitute improvements to the prediction of mosquito distribution and therefore identification of disease risk factors. Current methods for mosquito surveillance data collection are labor intensive and provide an extremely limited, incomplete picture of the species composition and abundance. Human surveillance data offers additional challenges with respect to reporting bias and resolution, but is nonetheless informative in identifying environmental risk factors and disease transmission dynamics. Remotely sensed imagery supports mosquito and human disease surveillance data by providing spatially explicit, line resolution information about environmental factors relevant to vector-borne disease processes. Together, surveillance and remotely sensed environmental data facilitate improved description and modeling of disease transmission. Remote sensing can be used to develop predictive maps of mosquito distribution in relation to disease risk. This has implications for increased accuracy of mosquito control efforts. The projects presented in this dissertation enhance current public health capacities by examining the applications of spatial modeling with respect to mosquito-borne disease.

  15. [Experience in suppressing the mosquito count in basement flooding in the city of Nukus].

    Science.gov (United States)

    Chabanenko, A A; Ermishev, Iu V; Stepnov, A P

    1991-01-01

    Large-scale trials of bacterial insecticides (Bac. sphaericus and Bac. thuringiensis) and of 5 synthetic pyrethroids were carried out in Nukus, Uzbekistan, in order to evaluate their effectiveness against Culex pipiens molestus Forsk (Diptera: Culicidae) breeding in flooded basements in urban areas. Lambdacyhaothrine (Karate, 5% e.c.) in the dosage of 0.01 g/m2 A. I. was found to be the most effective. Application of permethrine containing thermosublimated briquettes for quick elimination of adult mosquitoes combined with application of residual larvicides proved to be the best way to control basement breeding mosquitoes. PMID:1839053

  16. Tools for delivering entomopathogenic fungi to malaria mosquitoes: effects of delivery surfaces on fungal efficacy and persistence

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    Mnyone Ladslaus L

    2010-08-01

    Full Text Available Abstract Background Entomopathogenic fungi infection on malaria vectors increases daily mortality rates and thus represents a control measure that could be used in integrated programmes alongside insecticide-treated bed nets (ITNs and indoor residual spraying (IRS. Before entomopathogenic fungi can be integrated into control programmes, an effective delivery system must be developed. Methods The efficacy of Metarhizium anisopliae ICIPE-30 and Beauveria bassiana I93-825 (IMI 391510 (2 × 1010 conidia m-2 applied on mud panels (simulating walls of traditional Tanzanian houses, black cotton cloth and polyester netting was evaluated against adult Anopheles gambiae sensu stricto. Mosquitoes were exposed to the treated surfaces 2, 14 and 28 d after conidia were applied. Survival of mosquitoes was monitored daily. Results All fungal treatments caused a significantly increased mortality in the exposed mosquitoes, descending with time since fungal application. Mosquitoes exposed to M. anisopliae conidia on mud panels had a greater daily risk of dying compared to those exposed to conidia on either netting or cotton cloth (p B. bassiana conidia on mud panels or cotton cloth had similar daily risk of death (p = 0.14, and a higher risk than those exposed to treated polyester netting (p Conclusion Both fungal isolates reduced mosquito survival on immediate exposure and up to 28 d after application. Conidia were more effective when applied on mud panels and cotton cloth compared with polyester netting. Cotton cloth and mud, therefore, represent potential substrates for delivering fungi to mosquitoes in the field.

  17. The unexpected importance of mosquito oviposition behaviour for malaria: non-productive larval habitats can be sources for malaria transmission

    Directory of Open Access Journals (Sweden)

    Flahault Antoine

    2005-05-01

    Full Text Available Abstract 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.

  18. Do topical repellents divert mosquitoes within a community?

    OpenAIRE

    Maia Marta; Sangoro Peter; Thele Max; Turner Elizabeth; Moore Sarah

    2012-01-01

    Repellents are compounds which interfere with the mosquito’s olfactory system hindering them to identify their hosts and succeeding in taking a blood-meal [1]. However, repellents do not eliminate the host-seeking mosquitoes, they simply reduce human-vector contact. Consequently, there is a possibility that individuals, who do not use repellents, experience more bites than usual because mosquitoes are diverted from the repellent users. The objective of this study was to measure if diversion...

  19. The role of mosquito behaviour on parasite transmission

    OpenAIRE

    Ma, Brian Oh-bong

    2010-01-01

    I use a combination of theory and experiments to explore the role of various aspects of mosquito behaviour on the ability of mosquitoes to transmit parasites. Special focus is given to the mosquito Anopheles gambiae s.s., the principal vector for Plasmodium falciparum, a parasite that causes human malaria. Female mosquitoes require host blood for egg production, but also use sugar from nectar sources; however, the extent of sugar use is poorly understood. Sugar can be used to fuel somatic mai...

  20. Conditioning Individual Mosquitoes to an Odor: Sex, Source, and Time

    OpenAIRE

    Michelle R. Sanford; Tomberlin, Jeffery K

    2011-01-01

    Olfactory conditioning of mosquitoes may have important implications for vector-pathogen-host dynamics. If mosquitoes learn about specific host attributes associated with pathogen infection, it may help to explain the heterogeneity of biting and disease patterns observed in the field. Sugar-feeding is a requirement for survival in both male and female mosquitoes. It provides a starting point for learning research in mosquitoes that avoids the confounding factors associated with the observer b...

  1. Enhanced Survival of Plasmodium-Infected Mosquitoes during Starvation

    OpenAIRE

    Zhao, Yang O; Kurscheid, Sebastian; Zhang, Yue; Liu, Lei; Zhang,Lili; Loeliger, Kelsey; FIKRIG, EROL

    2012-01-01

    Plasmodium spp. are pathogenic to their vertebrate hosts and also apparently, impose a fitness cost on their insect vectors. We show here, however, that Plasmodium-infected mosquitoes survive starvation significantly better than uninfected mosquitoes. This survival advantage during starvation is associated with higher energy resource storage that infected mosquitoes accumulate during period of Plasmodium oocyst development. Microarray analysis revealed that the metabolism of sated mosquitoes ...

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

    OpenAIRE

    Smith, Ryan C.; Vega-rodri?guez, 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 pa...

  3. Aedes Mosquito Saliva Modulates Rift Valley Fever Virus Pathogenicity

    OpenAIRE

    Le Coupanec, Alain; Babin, Divya; Fiette, Laurence; Jouvion, Gre?gory; Ave, Patrick; Misse, Dorothee; Bouloy, Michèle; Choumet, Valerie

    2013-01-01

    BACKGROUND: Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. Mosquito saliva contains compounds that counteract the hemostatic, inflammatory, and immune responses of the host. Modulation of these defensive responses may facilitate virus infection. Indeed, Aedes mosquito saliva played a crucial role in the vector's capacity to effectively transfer arboviruses such as the Cache Valley and West Nile viruses. The role of mosquito saliva in the tr...

  4. The biology of malarial parasite in the mosquito: a review

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    Amauri Braga Simonetti

    1996-10-01

    Full Text Available The purpose of this review is to summarize the biology of Plasmodium in the mosquito including recent data to contribute to better understanding of the developmental interaction between mosquito and malarial parasite. The entire sporogonic cycle is discussed taking into consideration different parasite/vector interactions and factors affecting parasite development to the mosquito.

  5. Molecular Perspectives on the Genetics of Mosquitoes

    International Nuclear Information System (INIS)

    Mosquitoes have been a focus of scientific study since the turn of the century, when they were first linked with human diseases. This review concentrates on the three most intensely studied genera, Anopheles, Culex, and Aedes. These genera include the principal vectors of three major groups of human pathogens: malaria parasites of the genus Plasmodium, filarial worms of the genera Wuchereria and Brugia, and numerous arboviruses. Anophelines are the only mosquitoes known to transmit human malaria parasites, a group of organisms that may be responsible for more morbidity and mortality worldwide than any other human pathogen. Anophelines also transmit filarial worms, as do Culex and Aedes species. Among the 14 or more different mosquito genera known to harbor arboviruses (Mattingly, 1973), the most important are Culex and Aedes, which include the principal vectors of yellow fever, dengue, and most encephalitis-causing arboviruses.

  6. Evaluation of botanicals as repellents against mosquitoes

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    N.G. Das, I. Baruah, P.K. Talukdar & S.C. Das

    2003-03-01

    Full Text Available Repellent properties of three plant extracts—essential oil (steam distillate of Zanthoxylumlimonella (fruits, Citrus aurantifolia (leaf and petroleum ether extract of Z. limonella (fruitswere evaluated as repellent against Aedes (S. albopictus mosquitoes in mustard (Dhara and coconut(Parachute oil base under laboratory conditions. Three concentrations—10, 20 and 30% of therepellents were evaluated. Repellents in mustard oil afforded longer protection time against thebites of Aedes (S. albopictus mosquitoes than those in coconut oil. At 30% concentration, 296–304 min protection time was achieved by the test repellents in mustard oil base while repellents incoconut oil exhibited 223.5–245 min protection time at the same concentration. Oil of Z. limonellagave the highest protection time against the bites of Aedes (S. albopictus mosquitoes at all theconcentrations than other herbal repellents tested both in mustard and coconut oil.

  7. Potential negative impacts and low effectiveness in the use of African annual killifish in the biocontrol of aquatic mosquito larvae in temporary water bodies

    Directory of Open Access Journals (Sweden)

    Reichard Martin

    2010-09-01

    Full Text Available Abstract Commentary and discussion on a recent paper promoting the use of Nothobranchius guentheri, a small African annual fish from the Island of Zanzibar as a tool to control mosquito larvae in temporary bodies of freshwater throughout Africa is presented. Arguments on major points; (1 expected low success of annual fish introductions, (2 low success of mosquito control in the field, (3 ecological threats, and (4 ethical issues are detailed. Despite serious problems with mosquito-borne diseases in tropical Africa and elsewhere, we encourage responsible means of biological control of parasite vectors. We show that effectiveness of Nothobranchius translocations is low (the previous attempts failed, likelihood of effective mosquito larvae control under field condition is negligible and ecological threats from Nothobranchius translocations from within and outside the naturally occurring range are serious. We advocate against the proposed next step of the project, i.e. field trials in Tanzania.

  8. NO BUG: biobased mosquitoes repellent textiles

    OpenAIRE

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

    2011-01-01

    This research work is part of the FP7 No-Bug project (Novel release system and biobased utilities for insect repellent textiles). The main interest of the project is personal protective textiles against insects (mosquitoes) for application not only in tropical areas where vector borne diseases are a major threat to the public health but also in European countries where the presence of mosquitoes can be nuisance. Malaria and dengue fever are well known diseases that cause a lot of deaths in th...

  9. FIELD EVALUATION OF CDC AND MOSQUITO MAGNET® X TRAPS BAITED WITH DRY ICE, CO2 SACHET, AND OCTENOL AGAINST MOSQUITOES

    Science.gov (United States)

    CDC light traps and Mosquito Magnet® X (MMX) traps baited with dry ice, octenol, and a new formulation of CO2 (granular) were evaluated against mosquitoes in the field. The results showed that the MMX traps (68.6%) baited with dry ice collected more mosquitoes, compared to the CDC light traps (32.4%...

  10. Building a Better Mosquito: Identifying the Genes Enabling Malaria and Dengue Fever Resistance in A. gambiae and A. aegypti Mosquitoes

    OpenAIRE

    Dimopoulos, George

    2007-01-01

    In this interview, George Dimopoulos focuses on the physiological mechanisms used by mosquitoes to combat Plasmodium falciparum and dengue virus infections. Explanation is given for how key refractory genes, those genes conferring resistance to vector pathogens, are identified in the mosquito and how this knowledge can be used to generate transgenic mosquitoes that are unable to carry the malaria parasite or dengue virus.

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

    Directory of Open Access Journals (Sweden)

    Clement N. Mweya

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

    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

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

    Science.gov (United States)

    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

  14. Seasonal dynamics and habitat specificity of mosquitoes in an English wetland: implications for UK wetland management and restoration.

    Science.gov (United States)

    Medlock, Jolyon M; Vaux, Alexander G C

    2015-06-01

    We engaged in field studies of native mosquitoes in a Cambridgeshire Fen, investigating a) the habitat specificity and seasonal dynamics of our native fauna in an intensively managed wetland, b) the impact of water-level and ditch management, and c) their colonization of an arable reversion to flooded grassland wetland expansion project. Studies from April to October, 2010 collected 14,000 adult mosquitoes (15 species) over 292 trap-nights and ?4,000 pre-imaginal mosquitoes (11 species). Open floodwater species (Aedes caspius and Aedes cinereus, 43.3%) and wet woodland species (Aedes cantans/annulipes and Aedes rusticus, 32.4%) dominated, highlighting the major impact of seasonal water-level management on mosquito populations in an intensively managed wetland. In permanent habitats, managing marginal ditch vegetation and ditch drying significantly affect densities of pre-imaginal anophelines and culicines, respectively. This study presents the first UK field evidence of the implications of wetland expansion through arable reversion on mosquito colonization. Understanding the heterogeneity of mosquito diversity, phenology, and abundance in intensively managed UK wetlands will be crucial to mitigating nuisance and vector species through habitat management and biocidal control. PMID:26047189

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

    Science.gov (United States)

    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

  16. Pathogenicity of the Fungus, Aspergillus clavatus, Isolated from the Locust, Oedaleus senegalensis, Against Larvae of the Mosquitoes Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus

    OpenAIRE

    Seye, Fawrou; Faye, Oumar; Ndiaye, Mady; Njie, Ebrima; Marie Afoutou, Jose?

    2009-01-01

    The use of insect pathogenic fungi is a promising alternative to chemical control against mosquitoes. Among the Hyphomycetes isolated from insects for mosquito control, the genus Aspergillus remains the least studied. In September 2005, four fungi were isolated from the Senegalese locust, Oedaleus senegalensis Kraus (Orthoptera: Acrididae), collected in Dakar, Senegal. One of these fungi, identified as Aspergillus clavatus, Desmazières (Eurotiales: Trichocomaceae) was highly pathogenic again...

  17. Mosquitos (Díptera: Culicidae) vectores potenciales de arbovirus en la región de Urabá, noroccidente de Colombia[

    Scientific Electronic Library Online (English)

    Gabriel, Parra-Henao; Laura, Suárez.

    2012-06-01

    Full Text Available Introducción. Los estudios encaminados a conocer los parámetros ecológicos de las poblaciones de mosquitos selváticos, permiten establecer el riesgo de transmisión de arbovirus y aportar recomendaciones sobre prevención, vigilancia y control a las autoridades de salud. Objetivo. Determinar la divers [...] idad y abundancia de mosquitos nocturnos y crepusculares, potenciales vectores de arbovirus en zonas rurales de Apartadó y Turbo, Antioquia. Materiales y métodos. Se realizaron muestreos trimestrales. Para la recolección de mosquitos se usaron trampas CDC, Shannon y cebo humano protegido, en fragmentos de bosque, entre las 18:00 y las 06:00 horas. Se estimaron los índices de diversidad y abundancia de especies. Resultados. Se capturaron 583 mosquitos de 10 génerosy 27 especies. Las especies más abundantes fueron Coquilletidia venezuelensis (14,6 %), Aedes scapularis (14,08 %), Psorophora ferox (10,82 %) y Culex quinquefasciatus (10,3 %). La riqueza específica y los índices ecológicos calculados fueron mayores en Turbo; el fragmento de bosque estudiado en Turbo se considera de mayor riqueza y uniformidad de especies. El hallazgo de Cx. pedroi, Ae. scapularis, Ae. angustivittatus, Cq. venezuelensis, Cx. nigripalpus, Cx. quinquefasciatus, Cx. declarator, Mansonia titillans, Ma. pseudotitillans, Ps. ferox y Trichiprosopon digitatum reportados como vectores de arbovirus, alerta sobre la posibilidad de transmisión en la zona. Conclusión. La diversidad y abundancia de mosquitos en la zona de estudio son altas. Los análisis ecológicos más los reportes previos de capacidad vectorial de algunas de las especies registradas, permiten concluir que en la zona se pueden presentar brotes de arbovirosis. Abstract in english Mosquitoes (Diptera: Culiciadae) as potential vectors of arbovirused in the Urabá region, Northwest of Colombia [...

  18. The influence of mosquito resting behaviour and associated microclimate for malaria risk

    Directory of Open Access Journals (Sweden)

    Thomas Matthew B

    2011-07-01

    Full Text Available Abstract Background The majority of the mosquito and parasite life-history traits that combine to determine malaria transmission intensity are temperature sensitive. In most cases, the process-based models used to estimate malaria risk and inform control and prevention strategies utilize measures of mean outdoor temperature. Evidence suggests, however, that certain malaria vectors can spend large parts of their adult life resting indoors. Presentation of hypothesis If significant proportions of mosquitoes are resting indoors and indoor conditions differ markedly from ambient conditions, simple use of outdoor temperatures will not provide reliable estimates of malaria transmission intensity. To date, few studies have quantified the differential effects of indoor vs outdoor temperatures explicitly, reflecting a lack of proper understanding of mosquito resting behaviour and associated microclimate. Testing the hypothesis Published records from 8 village sites in East Africa revealed temperatures to be warmer indoors than outdoors and to generally show less daily variation. Exploring the effects of these temperatures on malaria parasite development rate suggested indoor-resting mosquitoes could transmit malaria between 0.3 and 22.5 days earlier than outdoor-resting mosquitoes. These differences translate to increases in transmission risk ranging from 5 to approaching 3,000%, relative to predictions based on outdoor temperatures. The pattern appears robust for low- and highland areas, with differences increasing with altitude. Implications of the hypothesis Differences in indoor vs outdoor environments lead to large differences in the limits and the intensity of malaria transmission. This finding highlights a need to better understand mosquito resting behaviour and the associated microclimate, and to broaden assessments of transmission ecology and risk to consider the potentially important role of endophily.

  19. Population genetic structure of Anopheles gambiae mosquitoes on Lake Victoria islands, west Kenya

    Directory of Open Access Journals (Sweden)

    Beier John

    2004-12-01

    Full Text Available Abstract Background Understanding the genetic structure of island Anopheles gambiae populations is important for the current tactics in mosquito control and for the proposed strategy using genetically-modified mosquitoes (GMM. Genetically-isolated mosquito populations on islands are a potential site for testing GMM. The objective of this study was to determine the genetic structure of A. gambiae populations on the islands in Lake Victoria, western Kenya. Methods The genetic diversity and the population genetic structures of 13 A. gambiae populations from five islands on Lake Victoria and six villages from the surrounding mainland area in the Suba District were examined using six microsatellite markers. The distance range of sampling sites varied between 2.5 and 35.1 km. Results A similar level of genetic diversity between island mosquito populations and adjacent mainland populations was found. The average number of alleles per locus was 7.3 for the island populations and 6.8 for the mainland populations. The average observed heterozygosity was 0.32 and 0.28 for the island and mainland populations, respectively. A low but statistically significant genetic structure was detected among the island populations (FST = 0.019 and between the island and mainland populations (FST = 0.003. A total of 12 private alleles were found, and nine of them were from the island populations. Conclusion A level of genetic differentiation between the island and mainland populations was found. Large extent of gene flow between the island and mainland mosquito populations may result from wind- or human-assisted dispersal. Should the islands on Lake Victoria be used as a trial site for the release program of GMM, mosquito dispersal between the islands and between the island and the mainland should be vigorously monitored.

  20. Oviposition Site Selection by the Dengue Vector Aedes aegypti and Its Implications for Dengue Control

    OpenAIRE

    Wong, Jacklyn; Stoddard, Steven T.; Astete, Helvio; Morrison, Amy C.; Scott, Thomas W.

    2011-01-01

    Controlling the mosquito Aedes aegypti is of public health importance because, at present, it is the only means to stop dengue virus transmission. Implementing successful mosquito control programs requires understanding what factors regulate population abundance, as well as anticipating how mosquitoes may adapt to control measures. In some species of mosquitoes, females choose egg-laying sites to improve the survival and growth of their offspring, a behavior that ultimately influences populat...

  1. An orbivirus of mosquitoes which induces CO2 sensitivity in mosquitoes and is lethal for rabbits.

    OpenAIRE

    Vazeille, M C; Rosen, L.; Guillon, J C

    1988-01-01

    An orbivirus, JKT-7400, isolated from Culex mosquitoes in Indonesia, replicated to a high titer and induced cytopathic effects in Aedes albopictus cell cultures. The virus produced lethal sensitivity to carbon dioxide in Culex and Aedes mosquitoes as well as in Drosophila melanogaster fruit flies but was not the agent of the hereditary sensitivity to carbon dioxide previously described for Culex quinquefasciatus. When injected intravenously in high doses, JKT-7400 virus was lethal for rabbits...

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

    Directory of Open Access Journals (Sweden)

    Kamareddine Layla

    2013-01-01

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

  3. Periodic dynamic systems for infected hosts and mosquitoes Sistemas dinâmicos periódicos para hospedeiros e mosquitos infectados

    Directory of Open Access Journals (Sweden)

    W. M. Oliva

    1996-06-01

    Full Text Available A mathematical model for the purpose of analysing the dynamic of the populations of infected hosts anf infected mosquitoes when the populations of mosquitoes are periodic in time is here presented. By the computation of a parameter lambda (the spectral radius of a certain monodromy matrix one can state that either the infection peters out naturally (lambda 1 the infection becomes endemic. The model generalizes previous models for malaria by considering the case of periodic coefficients; it is also a variation of that for gonorrhea. The main motivation for the consideration of this present model was the recent studies on mosquitoes at an experimental rice irrigation system, in the South-Eastern region of Brazil.Desenvolveu-se um modelo matemático para analisar a dinâmica das populações de indivíduos e mosquitos infectados quando as populações de mosquitos são periódicas no tempo. Pela determinação de um parâmetro lambda (o raio espectral de uma matriz de monodromia pode-se estabelecer que a infecção termina naturalmente (lambda 1 que a infecção torna-se endêmica. O modelo generaliza, para o caso de coeficientes periódicos, modelos anteriores para malária; como também é uma variação de modelo para a gonorréia. A principal motivação para a consideração do modelo proposto foram os recentes estudos sobre mosquitos numa estação experimental de arroz irrigado, na região Sudeste do Brasil.

  4. Why humans are attractive to malaria mosquitoes

    OpenAIRE

    Smallegange, R. C.; Qiu, Y.T.; Galimard, A.M.S.; Posthumus, M A; van Beek, T. A.; Loon, J.A., van; Takken, W.

    2003-01-01

    Malaria mosquitoes use host odours to find their blood sources, but little is known about the semiochemicals that mediate this behaviour. A combined study is undertaken to identify the volatile human-specific compounds that are used in the host-seeking behaviour of the females of Anopheles gambiae

  5. Musings on Sketches, Artists, and Mosquito Nets

    Centers for Disease Control (CDC) Podcasts

    2014-09-23

    Byron Breedlove reads his essay Musings on Sketches, Artists, and Mosquito Nets about the art of James Whistler and the transmission of vector borne diseases.  Created: 9/23/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/20/2014.

  6. Influence of trap construction on mosquito capture.

    Czech Academy of Sciences Publication Activity Database

    Šebesta, Old?ich; Peško, Juraj; Gelbi?, Ivan

    2012-01-01

    Ro?. 6, ?. 2 (2012), s. 209-215. ISSN 1934-7391 R&D Projects: GA MŠk 2B08003 Institutional research plan: CEZ:AV0Z50070508 Institutional support: RVO:68081766 ; RVO:60077344 Keywords : CDC miniature light traps * baited lard-can traps * mosquitoes Subject RIV: EG - Zoology

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

    Scientific Electronic Library Online (English)

    Analía, Francia; Arnaldo, Maciá.

    2011-12-01

    Full Text Available Las larvas de los mosquitos Aedes aegypti (Linneo) y Culex pipiens Linneo pueden criar conjuntamente en pequeños contenedores artificiales de agua, se genera así una competencia interespecífica y/o intraespecífica. El objetivo de este trabajo fue comparar la magnitud relativa de la competencia intra [...] e interespecífica en A. aegypti y C. pipiens, generada durante el desarrollo larval en contenedores artifi ciales. Las variables medidas como respuesta fueron la supervivencia y el tiempo de desarrollo larval, y la biomasa total producida en estado de pupa. Se criaron larvas de ambos mosquitos en neumáticos de automóvil con agua declorinada y hojarasca. Se introdujeron larvas recién eclosionadas de acuerdo a la densidad (5) estimada según un censo previo de A. aegypti y C. pipiens. Serealizaron los siguientes tratamientos agregando larvas de: (1) A. aegypti hasta alcanzar ? A. aegypti determinada según el censo previo, (2) C. pipiens hasta ? C. pipiens del censo previo, (3) A. aegypti hasta alcanzar la suma de ? A. aegypti y ? C. pipiens del censo previo, (4) C. pipiens hasta alcanzar la suma de ? A. aegypti y ? C. pipiens del censo previo y (5) A. aegypti y C. pipiens hasta ? A. aegypti y ? C. pipiens del censo previo. Las tres variables medidas fueron afectadas por los tratamientos, excepto la supervivencia y la biomasa producida por C. pipiens. Aedes aegypti fue más alterada por la competencia intraespecífica que por la competencia interespecífica. En C. pipiens, la competencia interespecífica superó en sus efectos a la competencia intraespecífica. Existió asimetría competitiva, ya que C. pipiens fue más afectada por A. aegypti que lo contrario. Abstract in english Larvae of Aedes aegypti (Linneo) and Culex pipiens Linneo may develop together in small artificial water containers, promoting inter- and/or intra-specific competition. Our aim was to compare the relative importance of interspecific and intraspecific competition in both species during larval develop [...] ment in artificial containers. Larvae were bred outdoors in automobile tires with leaf litteras the nutrient source. The number of experimental larvae was set after an assessment of densities (5) from wild populations. We established the treatments: 1: A. aegypti alone at the 5 of A. aegypti in the census; 2: C. pipiens alone at the 5 of C. pipiens in the census; 3: A. aegypti alone at the 5 of A. aegypti + C. pipiens in the census; 4: C. pipiens alone at the 5 A. aegypti + 5 C. pipiens in the census; and 5: A. aegypti at the 5 of A. aegypti in the census + C. pipiens at the 5 of C. pipiens in the census. Survivorship, development time and total biomass were affected by treatments, except for survivorship and biomass of C. pipiens. Intraspecific competition outweighed interspecific competiton in A. aegypti, while the opposite trend was detected in C. pipiens. Competition was asymmetric, as C. pipiens was more affected by A. aegypti.

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

    Directory of Open Access Journals (Sweden)

    Analía Francia

    2011-12-01

    Full Text Available Las larvas de los mosquitos Aedes aegypti (Linneo y Culex pipiens Linneo pueden criar conjuntamente en pequeños contenedores artificiales de agua, se genera así una competencia interespecífica y/o intraespecífica. El objetivo de este trabajo fue comparar la magnitud relativa de la competencia intra e interespecífica en A. aegypti y C. pipiens, generada durante el desarrollo larval en contenedores artifi ciales. Las variables medidas como respuesta fueron la supervivencia y el tiempo de desarrollo larval, y la biomasa total producida en estado de pupa. Se criaron larvas de ambos mosquitos en neumáticos de automóvil con agua declorinada y hojarasca. Se introdujeron larvas recién eclosionadas de acuerdo a la densidad (5 estimada según un censo previo de A. aegypti y C. pipiens. Serealizaron los siguientes tratamientos agregando larvas de: (1 A. aegypti hasta alcanzar ? A. aegypti determinada según el censo previo, (2 C. pipiens hasta ? C. pipiens del censo previo, (3 A. aegypti hasta alcanzar la suma de ? A. aegypti y ? C. pipiens del censo previo, (4 C. pipiens hasta alcanzar la suma de ? A. aegypti y ? C. pipiens del censo previo y (5 A. aegypti y C. pipiens hasta ? A. aegypti y ? C. pipiens del censo previo. Las tres variables medidas fueron afectadas por los tratamientos, excepto la supervivencia y la biomasa producida por C. pipiens. Aedes aegypti fue más alterada por la competencia intraespecífica que por la competencia interespecífica. En C. pipiens, la competencia interespecífica superó en sus efectos a la competencia intraespecífica. Existió asimetría competitiva, ya que C. pipiens fue más afectada por A. aegypti que lo contrario.Larvae of Aedes aegypti (Linneo and Culex pipiens Linneo may develop together in small artificial water containers, promoting inter- and/or intra-specific competition. Our aim was to compare the relative importance of interspecific and intraspecific competition in both species during larval development in artificial containers. Larvae were bred outdoors in automobile tires with leaf litteras the nutrient source. The number of experimental larvae was set after an assessment of densities (5 from wild populations. We established the treatments: 1: A. aegypti alone at the 5 of A. aegypti in the census; 2: C. pipiens alone at the 5 of C. pipiens in the census; 3: A. aegypti alone at the 5 of A. aegypti + C. pipiens in the census; 4: C. pipiens alone at the 5 A. aegypti + 5 C. pipiens in the census; and 5: A. aegypti at the 5 of A. aegypti in the census + C. pipiens at the 5 of C. pipiens in the census. Survivorship, development time and total biomass were affected by treatments, except for survivorship and biomass of C. pipiens. Intraspecific competition outweighed interspecific competiton in A. aegypti, while the opposite trend was detected in C. pipiens. Competition was asymmetric, as C. pipiens was more affected by A. aegypti.

  9. Relationships between anopheline mosquitoes and topography in West Timor and Java, Indonesia

    Science.gov (United States)

    2010-01-01

    Background Malaria is a serious health issue in Indonesia. Mosquito control is one aspect of an integrated malaria management programme. To focus resources on priority areas, information is needed about the vectors and their habitats. This research aimed to identify the relationship between anopheline mosquitoes and topography in West Timor and Java. Methods Study areas were selected in three topographic types in West Timor and Java. These were: coastal plain, hilly (rice field) and highland. Adult mosquitoes were captured landing on humans identified to species level and counted. Results Eleven species were recorded, four of which were significant for malaria transmission: Anopheles aconitus, Anopheles barbirostris, Anopheles subpictus and Anopheles sundaicus. Each species occupied different topographies, but only five were significantly associated: Anopheles annularis, Anopheles vagus and Anopheles subpictus (Java only) with hilly rice fields; Anopheles barbirostris, Anopheles maculatus and Anopheles subpictus (West Timor only) with coastal areas. Conclusion Information on significant malaria vectors associated with specific topography is useful for planning the mosquito control aspect of malaria management. PMID:20796265

  10. Microsporidia parásitos de larvas de mosquito de la Costa Pacífica del Chocó

    Directory of Open Access Journals (Sweden)

    Zuluaga Juan S.

    1993-12-01

    Full Text Available Two genera of Microsporidia were found infecting mosquito larvae in three localities on the Pacific coast of Choco. Vavraia sp. (Microsporida: Pleistophoridae was found in larvae of Wyeomyia circumcincta, W. simmsi and Anopheles albimanus collected from plants of the Bromeliacea family in Arusí y Joví. Amblyospora sp. (Microsporida: Amblyosporidae was found parasitizingAedes angustivittatuslarvae COllectedfrom a terrestrial breeding pond in the locality of Nuqur. Morphology of the spores of the two parasites under light microscopy is described, as well as preliminary data on host range when exposed to laboratory rearad Aedes aegypti, Culex quinquefasciatus and Anopheles albimanus. Their rola in mosquito control is discussed.Se reportan dos géneros de microsporidia que parasitan larvas de mosquitos en criaderos naturales de tres localidades en la costa Pacffica Chocoana. Vavraia sp. (Microsporida: Pleistophoridae parásita larvas de Wyeomyia circumcincta, de Wyeomya simmsi y de Anopheles neivai, recolectadas en las rosetas de especies de la familia Bromeliaceae en las localidades de Arusí y Joví. Amblyospora sp. (Microsporida: Amblyosporidae parásita larvas deAedes angustivittatusde criaderos terrestres semipermanentes en la localidad de Nuquí. Se describe la morfología de estos dos microsporidia al microscopio óptico. Estudios preliminares de infección en larvas de Aedes aegypti, Culex quinquefasciatus yAnopheles albimanus, criadas en laboratorio, indican que Vavraia sp. infecta las tres especies, con preferencia a Culex quinquefasciatus. Las larvas expuestas a esporas de Amblyospora sp. no presentaron infección. Se discute el posible papel de estos dos géneros en el control de las poblaciones de mosquitos.

  11. Seasonal mosquito larval abundance and composition in Kibwezi, lower eastern Kenya

    Directory of Open Access Journals (Sweden)

    Joseph M. Mwangangi

    2009-02-01

    Full Text Available Background & objectives: Changes in weather patterns especially rainfall affects the distribution and densities of mosquitoes. The objective of this study was to describe mosquito aquatic habitats, to determine larval abundance, species composition, and habitat types found in Kasayani village of Kibwezi division.Methods: A cross-sectional survey of mosquito larval habitats was conducted in Kasayani village in Kibwezi division to determine species composition, larval abundance, and habitat types found in this village. This survey was conducted during the rainy season in November and December 2006 and during the dry season in February and March 2007. Larvae were collected using the standard dipping technique and a total of 24 habitats were sampled. The primary habitats identified were water reservoir tanks, puddles, temporary pools, and tyre tracks. Results: A total of 2660 mosquito larvae were collected of which 2140 (80.45% were culicines, 503 (18.91% were Anopheles and 17 (0.64% were pupae. For culicines, 1787 (83.5% were categorized as early instars and 353 (16.5% were as late instars while in the Anopheles, 425 (84.49% were classified as early instars and 78 (15.51% were late instars. Morphological identification of the III and IV instar larvae by use of microscopy yielded 16.24% (n = 70 Anopheles gambiae complex, 1.16% (n = 5 An. funestus, 0.70% (n = 3 An. coustani, 42.46% (n = 183 Culex quinquefasciatus, 6.26% (n = 27 Cx. duttoni, and 33.18% (n = 143 Ae. aegypti. Puddles, tyre tracks and pools had highly turbid water while water reservoir tanks had clear water. Anopheles gambiae and Cx. quinquefasciatus were found in all habitat categories while Ae. aegypti were found only in water storage tanks. Interpretation & conclusion: The mosquito larval densities indicate that the inhabitants of this village are at risk of mosquito-borne diseases including malaria, which is one of the greatest causes of morbidity and mortality in this area. Furthermore, mosquito control measures targeting both the mosquito immatures and adults should be enhanced especially during the rainy season to ensure maximum protection of the inhabitants.

  12. Time-of-day specific changes in metabolic detoxification and insecticide resistance in the malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Balmert, Nathaniel J; Rund, Samuel S C; Ghazi, John P; Zhou, Peng; Duffield, Giles E

    2014-05-01

    Mosquitoes exhibit ?24 h rhythms in physiology and behavior, regulated by the cooperative action of an endogenous circadian clock and the environmental light:dark cycle. Here, we characterize diel (observed under light:dark conditions) time-of-day changes in metabolic detoxification and resistance to insecticide challenge in Anopheles gambiae mosquitoes. A better understanding of mosquito chronobiology will yield insights into developing novel control strategies for this important disease vector. We have previously identified >2000 rhythmically expressed An. gambiae genes. These include metabolic detoxification enzymes peaking at various times throughout the day. Especially interesting was the identification of rhythmic genes encoding enzymes capable of pyrethroid and/or DDT metabolism (CYP6M2, CYP6P3, CYP6Z1, and GSTE2). We hypothesized that these temporal changes in gene expression would confer time-of-day specific changes in metabolic detoxification and responses to insecticide challenge. An. gambiae mosquitoes (adult female Pimperena and Mali-NIH strains) were tested by gene expression analysis for diel rhythms in key genes associated with insecticidal resistance. Biochemical assays for total GST, esterase, and oxidase enzymatic activities were undertaken on time-specific mosquito head and body protein lysates. To determine for rhythmic susceptibility to insecticides by survivorship, mosquitoes were exposed to DDT or deltamethrin across the diel cycle. We report the occurrence of temporal changes in GST activity in samples extracted from the body and head with a single peak at late-night to dawn, but no rhythms were detected in oxidase or esterase activity. The Pimperena strain was found to be resistant to insecticidal challenge, and subsequent genomic analysis revealed the presence of the resistance-conferring kdr mutation. We observed diel rhythmicity in key insecticide detoxification genes in the Mali-NIH strain, with peak phases as previously reported in the Pimperena strain. The insecticide sensitive Mali-NIH strain mosquitoes exhibited a diel rhythm in survivorship to DDT exposure and a bimodal variation to deltamethrin challenge. Our results demonstrate rhythms in detoxification and pesticide susceptibility in An. gambiae mosquitoes; this knowledge could be incorporated into mosquito control and experimental design strategies, and contributes to our basic understanding of mosquito biology. PMID:24631684

  13. Resistencia a insecticidas en mosquitos (Diptera: Culicidae: mecanismos, deteccion y vigilancia en salud publica Inseclicide resistance in mosquitoes (Diptera: Culicidae: mechanisms, detection and monitoring in public health

    Directory of Open Access Journals (Sweden)

    IDALYD FONSECA

    2005-12-01

    Full Text Available Uno de los obstaculos mas serios en los programas de control de vectores de enfermedades humanas es el desarrollo de resistencia a los insecticidas usados. Segun la Organizacion Mundial de la Salud, aproximadamente el 40% de los 506 artropodos de importancia medica presentan algun grado de resistencia a insecticidas. De estas especies. cerca del 50% son especies de mosquitos vectores de malaria, dengue, fiebre amarilla y filariasis. Los dos principales mecanismos de resistencia a insecticidas son las alteraciones en el sitio blanco y un incremento en la tasa de detoxificacion de los insecticidas. Una vez se detectan niveles de resistencia en una poblacion de vectores es fundamental determinar su base bioquimica y molecular. La identificacion de los mecanismos de resistencia permite la seleccion de los insecticidas a usar en los programas de control y la evaluacion del potencial desarrollo de resistencia a insecticidas alternativos. Esta revision presenta informacion basica acerca de los principales mecanismos de resistencia a insecticidas identificados en mosquitos vectores de enfermedades humanas y las metodologias mas usadas para su vigilancia y deteccion.Among the most serious obstacles in vector control programs for human diseases is the development of resistance to the insecticides used. According to WHO, approximately 40% of the 506 medically important arthropods show some degree of insecticide resistance. Of these species, about 50% arc species of mosquitoes that vector malaria, dengue, yellow fever and filariasis. The two principal mechanisms of insecticide resistance are alterations in the target site or an increase in the detoxification rate ofthe insecticide. Once resistance is detected in a vector population it is crucial to determine its molecular and biochemical basis. Identification of resistance mechanisms permits the selection of insecticides to use in control programs and the evaluation of potential development of resistance to alternative insecticides. This review presents basic information regarding the main mechanisms of insecticide resistance identifico in mosquito vectors of human diseases and the methodologies most used to monitor and detect them.

  14. Resistencia a insecticidas en mosquitos (Diptera: Culicidae): mecanismos, deteccion y vigilancia en salud publica / Inseclicide resistance in mosquitoes (Diptera: Culicidae): mechanisms, detection and monitoring in public health

    Scientific Electronic Library Online (English)

    IDALYD, FONSECA; MARTHA L, QUINOÑES.

    2005-12-01

    Full Text Available Uno de los obstaculos mas serios en los programas de control de vectores de enfermedades humanas es el desarrollo de resistencia a los insecticidas usados. Segun la Organizacion Mundial de la Salud, aproximadamente el 40% de los 506 artropodos de importancia medica presentan algun grado de resistenc [...] ia a insecticidas. De estas especies. cerca del 50% son especies de mosquitos vectores de malaria, dengue, fiebre amarilla y filariasis. Los dos principales mecanismos de resistencia a insecticidas son las alteraciones en el sitio blanco y un incremento en la tasa de detoxificacion de los insecticidas. Una vez se detectan niveles de resistencia en una poblacion de vectores es fundamental determinar su base bioquimica y molecular. La identificacion de los mecanismos de resistencia permite la seleccion de los insecticidas a usar en los programas de control y la evaluacion del potencial desarrollo de resistencia a insecticidas alternativos. Esta revision presenta informacion basica acerca de los principales mecanismos de resistencia a insecticidas identificados en mosquitos vectores de enfermedades humanas y las metodologias mas usadas para su vigilancia y deteccion. Abstract in english Among the most serious obstacles in vector control programs for human diseases is the development of resistance to the insecticides used. According to WHO, approximately 40% of the 506 medically important arthropods show some degree of insecticide resistance. Of these species, about 50% arc species [...] of mosquitoes that vector malaria, dengue, yellow fever and filariasis. The two principal mechanisms of insecticide resistance are alterations in the target site or an increase in the detoxification rate ofthe insecticide. Once resistance is detected in a vector population it is crucial to determine its molecular and biochemical basis. Identification of resistance mechanisms permits the selection of insecticides to use in control programs and the evaluation of potential development of resistance to alternative insecticides. This review presents basic information regarding the main mechanisms of insecticide resistance identifico in mosquito vectors of human diseases and the methodologies most used to monitor and detect them.

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

    Science.gov (United States)

    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. Identificación de una fuente humana de alimentación de mosquitos mediante la técnica de coaglutinación

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    MAYDA CASTEX

    1997-08-01

    Full Text Available Se describe la utilización de la técnica de coaglutinación para la identificación de una fuente humana de alimentación de mosquitos. La dilución de las muestras de sangre ingerida en papel de filtro se hizo en 2 mL de una solución de cloruro de sodio al 0,85 %. Se utilizó una suspensión de estafilococos sensibilizados con un suero normal de conejo como control negativo. La suspensión de Staphylococcus aureus sensibilizados con suero de conejo anti-proteínas plasmáticas humanas y suero de conejo anti-IgG humana discriminó bien entre sangre humana y no humana. No se observó aglutinación con el control negativo. Esta técnica resultó ser sensible para identificar el 100 % de las muestras de sangre humana llevadas al papel 24 h después de que los mosquitos completaron su alimentación a una temperatura de 26 a 28 °C. En mosquitos alimentados y colectados en el campo, la prueba se comportó de forma satisfactoria, en consecuencia puede ser utilizada en trabajos de rutina en el campo. Los resultados mostraron la sensibilidad y especificidad de este método para la identificación de sangre humana ingerida por mosquitos.The utilization of a coagglutination technique for the identification of a human source for feeding mosquitoes is described. The dilution of ingested blood samples in filter paper was performed in 2 mL of a sodium chloride solution at 0.85 %. It was used a suspension of sensibilized Staphylococcus aureus with rabbit's serum, human plasmatic anti-proteins, and human anti-IgG rabbit's serum discriminated well between human and non human blood. No agglutination was observed with the negative control. This technique proved to be sensitive to identify 100 % of the human blood samples taken to the paper 24 hours after the mosquitoes completed their feeding at a temperature of 26 to 28 °C. Among mosquitoes fed and collected in the fields the test had a satisfactory result. Therefore, it may be used in routine work in the fields. The results showed the sensitivity and specificity of this method for identifying human blood ingested by mosquitoses.

  17. Simulation Modelling of Population Dynamics of Mosquito Vectors for Rift Valley Fever Virus in a Disease Epidemic Setting

    DEFF Research Database (Denmark)

    Mweya, Clement N.; Holst, Niels

    2014-01-01

    Background: Rift Valley Fever (RVF) is weather dependent arboviral infection of livestock and humans. Population dynamics of mosquito vectors is associated with disease epidemics. In our study, we use daily temperature and rainfall as model inputs to simulate dynamics of mosquito vectors population in relation to disease epidemics. Methods/Findings: Time-varying distributed delays (TVDD) and multi-way functional response equations were implemented to simulate mosquito vectors and hosts developmental stages and to establish interactions between stages and phases of mosquito vectors in relation to vertebrate hosts for infection introduction in compartmental phases. An open-source modelling platforms, Universal Simulator and Qt integrated development environment were used to develop models in C++ programming language. Developed models include source codes for mosquito fecundity, host fecundity, water level, mosquito infection, host infection, interactions, and egg time. Extensible Markup Language (XML) files were used as recipes to integrate source codes in Qt creator with Universal Simulator plug-in. We observed that Floodwater Aedines and Culicine population continued to fluctuate with temperature and water level over simulation period while controlled by availability of host for blood feeding. Infection in the system was introduced by floodwater Aedines. Culicines pick infection from infected host once to amplify disease epidemic. Simulated mosquito population show sudden unusual increase between December 1997 and January 1998 a similar period when RVF outbreak occurred in Ngorongoro district. Conclusion/Significance: Findings presented here provide new opportunities for weather-driven RVF epidemic simulation modelling. This is an ideal approach for understanding disease transmission dynamics towards epidemics prediction, prevention and control. This approach can be used as an alternative source for generation of calibrated RVF epidemics data in different settings.

  18. Selection of mosquito life-histories: a hidden weapon against malaria?

    OpenAIRE

    Ferguson Heather M; Maire Nicolas; Takken Willem; Lyimo Issa N; Briët Olivier; Lindsay Steve W; Smith Thomas A

    2012-01-01

    Abstract Background There has recently been a substantial decline in malaria incidence in much of Africa. While the decline can clearly be linked to increasing coverage of mosquito vector control interventions and effective drug treatment in most settings, the ubiquity of reduction raises the possibility that additional ecological and associated evolutionary changes may be reinforcing the effectiveness of current vector control strategies in previously unanticipated ways. Presentation of hypo...

  19. Pharmacological Validation of an Inward-Rectifier Potassium (Kir) Channel as an Insecticide Target in the Yellow Fever Mosquito Aedes aegypti

    Science.gov (United States)

    Rouhier, Matthew F.; Raphemot, Rene; Denton, Jerod S.; Piermarini, Peter M.

    2014-01-01

    Mosquitoes are important disease vectors that transmit a wide variety of pathogens to humans, including those that cause malaria and dengue fever. Insecticides have traditionally been deployed to control populations of disease-causing mosquitoes, but the emergence of insecticide resistance has severely limited the number of active compounds that are used against mosquitoes. Thus, to improve the control of resistant mosquitoes there is a need to identify new insecticide targets and active compounds for insecticide development. Recently we demonstrated that inward rectifier potassium (Kir) channels and small molecule inhibitors of Kir channels offer promising new molecular targets and active compounds, respectively, for insecticide development. Here we provide pharmacological validation of a specific mosquito Kir channel (AeKir1) in the yellow fever mosquito Aedes aegypti. We show that VU590, a small-molecule inhibitor of mammalian Kir1.1 and Kir7.1 channels, potently inhibits AeKir1 but not another mosquito Kir channel (AeKir2B) in vitro. Moreover, we show that a previously identified inhibitor of AeKir1 (VU573) elicits an unexpected agonistic effect on AeKir2B in vitro. Injection of VU590 into the hemolymph of adult female mosquitoes significantly inhibits their capacity to excrete urine and kills them within 24 h, suggesting a mechanism of action on the excretory system. Importantly, a structurally-related VU590 analog (VU608), which weakly blocks AeKir1 in vitro, has no significant effects on their excretory capacity and does not kill mosquitoes. These observations suggest that the toxic effects of VU590 are associated with its inhibition of AeKir1. PMID:24959745

  20. Mosquito and sand fly gregarines of the genus Ascogregarina and Psychodiella (Apicomplexa: Eugregarinorida, Aseptatorina)--overview of their taxonomy, life cycle, host specificity and pathogenicity.

    Science.gov (United States)

    Lantova, Lucie; Volf, Petr

    2014-12-01

    Mosquitoes and sand flies are important blood-sucking vectors of human diseases such as malaria or leishmaniasis. Nevertheless, these insects also carry their own parasites, such as gregarines; these monoxenous pathogens are found exclusively in invertebrates, and some of them have been considered useful in biological control. Mosquito and sand fly gregarines originally belonging to a single genus Ascogregarina were recently divided into two genera, Ascogregarina comprising parasites of mosquitoes, bat flies, hump-backed flies and fleas and Psychodiella parasitizing sand flies. Currently, nine mosquito Ascogregarina and five Psychodiella species are described. These gregarines go through an extraordinarily interesting life cycle; the mosquito and sand fly larvae become infected by oocysts, the development continues transtadially through the larval and pupal stages to adults and is followed by transmission to the offspring by genus specific mechanisms. In adult mosquitoes, ascogregarines develop in the Malpighian tubules, and oocysts are defecated, while in the sand flies, the gregarines are located in the body cavity, their oocysts are injected into the accessory glands of females and released during oviposition. These life history differences are strongly supported by phylogenetical study of SSU rDNA proving disparate position of Ascogregarina and Psychodiella gregarines. This work reviews the current knowledge about Ascogregarina and Psychodiella gregarines parasitizing mosquitoes and sand flies, respectively. It gives a comprehensive insight into their taxonomy, life cycle, host specificity and pathogenicity, showing a very close relationship of gregarines with their hosts, which suggests a long and strong parasite-host coevolution. PMID:24797386

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

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    Byarugaba Wilson

    2009-07-01

    Full Text Available Abstract 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. Structurally, introns are a six-moiety complex. Depending on the function of the protein encoded within the IV moiety, the highly mobile class of group II introns or retroposons is sub-divided into two: Restriction Endonuclease (REase-like and Apurinic aPyramydinic Endonuclease (APE-like. REase-like retroposons are thought to be the ancestors of APE retroposons. Our aim in this study was to find evidence for the highly species-specific conservation of the APE subclass of mosquito retroposons. Methods and Results In silico targeted sequence alignments were conducted across a 1,779-organism genome database (1,518 bacterial, 59 archeal, 201 eukaryotic, and the human, using three mosquito retroposon sequence tags (RST as BLASTN queries [AJ970181 and AJ90201 of Culex pipien origin and AJ970301 of Anoplese sinensis origin]. At a calibration of E = 10, A & D = 100, default filtration and a homology cut-off of >95% identity, no hits were found on any of the 1,518 bacterial genomes. Eleven (100% and 15 (100% hits obtained on the 201-eukaryote genome database were homologs (>95% score of C.pipien quinquefasciatus JHB retroposons, but none of An. sinensis. Twenty and 221 low score (30–43% identity spurious hits were found at flanking ends of genes and contigs in the human genome with the C.pipien and An. sinensis RSTs respectively. Functional and positional inference revealed these to be possible relatives of human genomic spliceosomes. We advance two models for the application of mosquito RST: as precursors for developing molecular biomarkers for mosquitoes, and as RST-specific monoclonal antibody (MAb-DDT immunoconjugates to enhance targeted toxicity. Conclusion We offer evidence to support the species-specific conservation of mosquito retroposons among lower taxa. Our findings suggest that retroposons may therefore constitute a unique biomarker for mosquito species that may be exploited in molecular entomology. Mosquito RST-specific MAbs may possibly permit synthesis of DDT immunoconjugates that could be used to achieve species-tailored toxicity.

  2. Source Reduction Behavior as an Independent Measurement of the Impact of a Public Health Education Campaign in an Integrated Vector Management Program for the Asian Tiger Mosquito

    Directory of Open Access Journals (Sweden)

    Daniel Strickman

    2011-05-01

    Full Text Available The goal of this study was to evaluate the effectiveness of a public health educational campaign to reduce backyard mosquito-larval habitats. Three communities each, within two New Jersey counties, were randomly selected to receive: (1 both education and mosquito control, (2 education only, and (3 no education or mosquito control. Four separate educational events included a 5-day elementary school curriculum in the spring, and three door to door distributions of educational brochures. Before and after each educational event, the numbers of mosquito-larval container habitats were counted in 50 randomly selected homes per study area. Container surveys allowed us to measure source reduction behavior. Although we saw reductions in container habitats in sites receiving education, they were not significantly different from the control. Our results suggest that traditional passive means of public education, which were often considered the gold standard for mosquito control programs, are not sufficient to motivate residents to reduce backyard mosquito-larval habitats.

  3. Studies on mosquitoes breeding in rock pools on inselbergs around Zaria, northern Nigeria

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    David A. Adebote

    2008-02-01

    Full Text Available Background & objectives: Rainwater often collects in depressions on rocks to form pools that are ideal breeding sites of mosquito vectors of diseases. Knowledge on the existence of disease vectors in these remote and relatively inaccessible locations could improve epidemiologic understanding and control capabilities. This study identifies mosquito species, their relative abundance and physicochemical characteristics of breeding microhabitats in rock pools on four inselbergs in northern Nigeria.Methods: Soup ladle dipper was used to obtain representative samples of larval mosquitoes breeding in 141 rock pools on four inselbergs. Physicochemical parameters (depth, electrical conductivity, pH, surface area, temperature and total dissolved solids of the pools were determined. Larvae were preserved in 70% alcohol and identified microscopically to species using taxonomic keys. Statistical correlation analysis and ANOVA were used to test the associations between physicochemical parameters and mosquito abundance, and for differences amongst inselbergs. Results: Of 2991 larvae, five species of mosquito distributed in three genera (Anopheles, Aedes and Culex including Ae. vittatus (92.88%, An. ardensis (0.13%, An. distinctus (1.67%, An. wilsoni (0.13% and Cx. ingrami (5.18% bred in the rock pools, Up to five species occurred per pool in various conspecific and heterogeneric combinations. Except for Ae. vittatus, the physicochemical parameters of the pools correlate significantly with species abundance. Conclusion: Ae. vittatus, a potential vector of yellow fever in Nigeria breeds profusely in rock pools on inselbergs around Zaria. For comprehensive vector implication and control, rock pools should be amongst the habitats of focus in yellow fever epidemiology.

  4. Biodistribution and Toxicity Studies of PRINT Hydrogel Nanoparticles in Mosquito Larvae and Cells

    Science.gov (United States)

    Phanse, Yashdeep; Dunphy, Brendan M.; Perry, Jillian L.; Airs, Paul M.; Paquette, Cynthia C. H.; Carlson, Jonathan O.; Xu, Jing; Luft, J. Christopher; DeSimone, Joseph M.; Beaty, Barry J.; Bartholomay, Lyric C.

    2015-01-01

    Mosquito-borne diseases continue to remain major threats to human and animal health and impediments to socioeconomic development. Increasing mosquito resistance to chemical insecticides is a great public health concern, and new strategies/technologies are necessary to develop the next-generation of vector control tools. We propose to develop a novel method for mosquito control that employs nanoparticles (NPs) as a platform for delivery of mosquitocidal dsRNA molecules to silence mosquito genes and cause vector lethality. Identifying optimal NP chemistry and morphology is imperative for efficient mosquitocide delivery. Toward this end, fluorescently labeled polyethylene glycol NPs of specific sizes, shapes (80 nm x 320 nm, 80 nm x 5000 nm, 200 nm x 200 nm, and 1000 nm x 1000 nm) and charges (negative and positive) were fabricated by Particle Replication in Non-Wetting Templates (PRINT) technology. Biodistribution, persistence, and toxicity of PRINT NPs were evaluated in vitro in mosquito cell culture and in vivo in Anopheles gambiae larvae following parenteral and oral challenge. Following parenteral challenge, the biodistribution of the positively and negatively charged NPs of each size and shape was similar; intense fluorescence was observed in thoracic and abdominal regions of the larval body. Positively charged NPs were more associated with the gastric caeca in the gastrointestinal tract. Negatively charged NPs persisted through metamorphosis and were observed in head, body and ovaries of adults. Following oral challenge, NPs were detected in the larval mid- and hindgut. Positively charged NPs were more efficiently internalized in vitro than negatively charged NPs. Positively charged NPs trafficked to the cytosol, but negatively charged NPs co-localized with lysosomes. Following in vitro and in vivo challenge, none of the NPs tested induced any cytotoxic effects. PMID:25996390

  5. Biodistribution and Toxicity Studies of PRINT Hydrogel Nanoparticles in Mosquito Larvae and Cells.

    Science.gov (United States)

    Phanse, Yashdeep; Dunphy, Brendan M; Perry, Jillian L; Airs, Paul M; Paquette, Cynthia C H; Carlson, Jonathan O; Xu, Jing; Luft, J Christopher; DeSimone, Joseph M; Beaty, Barry J; Bartholomay, Lyric C

    2015-05-01

    Mosquito-borne diseases continue to remain major threats to human and animal health and impediments to socioeconomic development. Increasing mosquito resistance to chemical insecticides is a great public health concern, and new strategies/technologies are necessary to develop the next-generation of vector control tools. We propose to develop a novel method for mosquito control that employs nanoparticles (NPs) as a platform for delivery of mosquitocidal dsRNA molecules to silence mosquito genes and cause vector lethality. Identifying optimal NP chemistry and morphology is imperative for efficient mosquitocide delivery. Toward this end, fluorescently labeled polyethylene glycol NPs of specific sizes, shapes (80 nm x 320 nm, 80 nm x 5000 nm, 200 nm x 200 nm, and 1000 nm x 1000 nm) and charges (negative and positive) were fabricated by Particle Replication in Non-Wetting Templates (PRINT) technology. Biodistribution, persistence, and toxicity of PRINT NPs were evaluated in vitro in mosquito cell culture and in vivo in Anopheles gambiae larvae following parenteral and oral challenge. Following parenteral challenge, the biodistribution of the positively and negatively charged NPs of each size and shape was similar; intense fluorescence was observed in thoracic and abdominal regions of the larval body. Positively charged NPs were more associated with the gastric caeca in the gastrointestinal tract. Negatively charged NPs persisted through metamorphosis and were observed in head, body and ovaries of adults. Following oral challenge, NPs were detected in the larval mid- and hindgut. Positively charged NPs were more efficiently internalized in vitro than negatively charged NPs. Positively charged NPs trafficked to the cytosol, but negatively charged NPs co-localized with lysosomes. Following in vitro and in vivo challenge, none of the NPs tested induced any cytotoxic effects. PMID:25996390

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

    Science.gov (United States)

    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.

  7. Di-rhamnolipid is a mosquito pupicidal metabolite from Pseudomonas fluorescens (VCRC B426).

    Science.gov (United States)

    Prabakaran, G; Hoti, S L; Prakash Rao, H Surya; Vijjapu, Satish

    2015-08-01

    Pseudomonas fluorescens Migula (VCRC B426) produces a secondary metabolite, which was found to be active against pupae of vector mosquitoes namely Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. The mosquito pupicidal metabolite from P. fluoescens was mass produced and separated by ethyl acetate extraction and purified further by silica gel column chromatography, FPLC, HPLC and TLC. The purified metabolite was characterized by NMR, FT-IR, LC-MS and MALDI-TOF. The FT-IR, (1)H and (13)C NMR results showed that it is a rhamnolipid (di-rhamnolipid). The matrix assisted laser desorption and ionization-time-of-flight spectrum of the sample showed predominant pupicidal component produced by P. fluorescens was the molecule mass of 673.40Da. Owing to its high toxicity to mosquito pupae, especially Anopheles sp., and Aedes sp., the di-rhamnolipd has potential in the control of the vectors of dengue, chikungunya, yellow fever and malaria. This is the first report of mosquito pupicidal di-rhamnolipid from P. fluorescens. PMID:25912083

  8. Insecticide susceptibility of Anopheles coluzzii and Anopheles gambiae mosquitoes in Ibadan, Southwest Nigeria.

    Science.gov (United States)

    Okorie, P N; Ademowo, O G; Irving, H; Kelly-Hope, L A; Wondji, C S

    2015-03-01

    The emergence of insecticide resistance in Anopheles (Diptera: Culicidae) mosquitoes has great implications for malaria control in Nigeria. This study aimed to determine the dynamics of insecticide susceptibility levels and the frequency of knock-down resistance (kdr) mutations (L1014F) in wild Anopheles coluzzii Coetzee & Wilkerson sp. n. and Anopheles gambiae Giles from the Ojoo and Bodija areas of Ibadan, in southwest Nigeria. Insecticide susceptibility to pyrethroids, organophosphates, carbamates and organochlorines was assessed using World Health Organization (WHO) bioassays. A subset of the mosquitoes exposed to pyrethroids and DDT was used for species and molecular form identification; kdr genotyping was determined using the TaqMan real-time polymerase chain reaction assay. The mosquitoes were resistant to pyrethroids and DDT but completely susceptible to organophosphates and carbamates. Bodija samples (n?=?186) consisted of An.?gambiae (91.4%) and An.?coluzzii (8.1%) and included one An.?coluzzii/An.?gambiae hybrid specimen. All mosquitoes screened in Ojoo (n?=?26) were An.?gambiae. The 1014F kdr mutation was detected at frequencies of 24.5 and 5.8% in Bodija and Ojoo, respectively. No correlation was observed between kdr genotypes and resistance phenotypes. The results indicate that metabolic resistance probably plays an important role in the development of resistance and highlight the need to implement insecticide resistance management strategies. PMID:25417803

  9. ELISA as an alternative tool for epidemiological surveillance for dengue in mosquitoes: a report from Thailand

    Directory of Open Access Journals (Sweden)

    Mayuna Srisuphanunt, Ratana Sithiprasasna, Somboon Patpoparn, Watcharee Attatippaholkun & Viroj Wiwanitkit

    2007-12-01

    Full Text Available Background & objectives: Dengue fever (DF, dengue hemorrhagic fever (DHF and dengue shocksyndrome (DSS are the re-emerging infectious diseases caused by the four serotypes of dengue(DEN virus, type 1 to 4, belonging to the family Flaviviridae and genus Flavivirus. In the absenceof a safe and effective mass immunisation, the prevention and control of dengue outbreaks dependupon the surveillance of cases and mosquito vector. The aim of this work is to test enzyme-linkedimmunosorbent assay (ELISA tool for the virological surveillance of dengue.Methods: Virus-infected Aedes mosquitoes were collected from the field in order to serve as anearly warning monitoring tool for dengue outbreaks. In a prospective field study conducted fromApril to September 2000, female adult Aedes mosquitoes were caught from selected dengue-sensitivearea in Chombung district, Ratchaburi province and assayed by ELISA.Result: Approximately 18.3% were found positive for dengue virus.Conclusion: This can imply that ELISA can be an alternative tool for epidemiological surveillancefor dengue in mosquitoes.

  10. Rift Valley Fever Virus (RVFv Dissemination inside Mosquitoes and Investigation of the Influence of Climate on Mosquitoes Abundance

    Directory of Open Access Journals (Sweden)

    Rania Ali El Hadi Mohamed

    2013-10-01

    Full Text Available One year surveys were conducted at two sites in Khartoum State capital of Sudan: Hellat Kuku and Soba West. The study was focused into two species of mosquitoes: Aedes vexans and Culex quinquefasciatus. This selection was based on previous investigations indicated their being positive for RVF. The study aimed to investigate on RVFv dissemination inside two species mosquitoes in Khartoum State (Sudan and investigation of the influence of climate on mosquitoes abundance. Weekly aspiration of wild mosquitoes has been conducted during 1st July 2011- 1st July 2012. The collected mosquitoes were identified by using classical keys. Data of climate were obtained from Sudan Meteorology Authorities. Males and females of the two mosquitoes species were divided into three cohorts: salivary glands, abdomen, and wings and legs. RVF Virus was therefore examined into twelve pools using Real- Time PCR technique. Results showed that Temperature, precipitation, and RH were significantly associated with the number of aspirated mosquitoes. The virus has been detected inside the pools of the abdomen and salivary glands of Ae. vexans mosquitoes. However, pools of salivary glands of Cx. quinquefasciatus were negative of the virus in spite of dissemination of the virus in the wings and legs. Based on these results it can be concluded that climatic factors affected on the number of aspirated mosquitoes during the study period. Ae. vexans mosquitoes exhibited an indicator of being competent to transmit the virus in contrast to Cx. quinquefasciatus.

  11. The central role of mosquito cytochrome P450 CYP6Zs in insecticide detoxification revealed by functional expression and structural modelling

    OpenAIRE

    Chandor-proust, Alexia; Bibby, Jaclyn; Re?gent-kloeckner, Myriam; Roux, Jessica; Guittard-crilat, Emilie; Poupardin, Rodolphe; Riaz, Muhammad asam; Paine, Mark; Dauphin-villemant, Chantal; Reynaud, Ste?phane; David, Jean-philippe

    2013-01-01

    The resistance of mosquitoes to chemical insecticides is threatening vector control programmes worldwide. Cytochrome P450 monooxygenases (CYPs) are known to play a major role in insecticide resistance, allowing resistant insects to metabolize insecticides at a higher rate. Among them, members of the mosquito CYP6Z subfamily, like Aedes aegypti CYP6Z8 and its Anopheles gambiae orthologue CYP6Z2, have been frequently associated with pyrethroid resistance. However, their role in the pyrethroid d...

  12. Arctic Health Research Center report no. 101: Combating mosquitoes in arctic Alaska

    US Fish and Wildlife Service, Department of the Interior — This report covers combating mosquitoes in Arctic Alaska. The physiology and biology of mosquitoes is discussed, followed by techniques to combated mosquitoes.

  13. Spinosad: a biorational mosquito larvicide for use in car tires in southern Mexico

    Directory of Open Access Journals (Sweden)

    Marina Carlos F

    2012-05-01

    Full Text Available Abstract Background Car tires are important habitats for mosquito development because of the high density populations they can harbor and their presence in urban settings. Water in experimental tires was treated with one of three insecticides or an untreated control. Aquatic invertebrates were sampled at weekly intervals. Eggs, larval and pupal samples were laboratory-reared to estimate seasonal fluctuations in Aedes aegypti and Ae. albopictus abundance. Results Spinosad treatments at 1 or 5?ppm (mg a.i./liter provided 6–8?weeks of effective control of Ae. aegypti, Ae. albopictus, Culex quinquefasiatus and Cx. coronator larvae, both in the dry season and the rainy season when mosquito populations increased markedly in southern Mexico. Spinosad continued to provide partial control of larvae for several weeks after initial recolonization of treated tires. The larvicidal performance of VectoBac 12AS (Bacillus thuringiensis var. israelensis was relatively poor with one week of complete control of Aedes spp. larvae and no discernible control of Culex spp., whereas the duration of larvicidal activity of 1% temephos mineral-based granules was intermediate between those of VectoBac and spinosad treatments. Populations of chironomids, ostracods and Toxorhynchites theobaldi were generally reduced in spinosad and temephos treatments, but were similar in control and VectoBac treatments. Conclusion The present study is the first to report spinosad as an effective larvicide against Cx. coronator, which is currently invading the southern United States. These results substantiate the use of spinosad as a highly effective mosquito larvicide, even in habitats such as unused car tires that can represent prolific sources of adult mosquitoes.

  14. The cell biology of mosquito vitellogenesis

    Scientific Electronic Library Online (English)

    Alexander S., Raikhel.

    Full Text Available Insect vitellogenesis involves coordinated activities of the fat body and oocytes. We have studied these activities at the cellular level in the mosquito. During each vitellogenic cycle, the fat body undergoes three successive stages: 1) proliferation of biosynthetic organelles, 2) vitellogenin synt [...] hesis, 3) termination of vitellogenin synthesis and degradation of biosynthetic organelles by lysosomes. Analysis with monoclonal antibodies and radiolabelling demonstrated that the mosquito yolk protein consists of two subunits (200-kDa and 65-kDa). Both subunits are glycosylated, their carbohydrate moieties are composed of high-mannose oligosaccharides. The yolk protein subunits are derived from a single 220 kDa precursor detected by an in vitro translation. Oocytes become competent to internalize proteins as a result of juvenile hormone-mediated biogenesis of endocytotic organelles. The yolk protein is then accumulated by receptor-mediated endocytosis. A pathway of the yold protein and factors determining its routing in the oocyte have been studied.

  15. Genetic Control of Mosquitoes: population suppression strategies Controle genético de mosquitos: estratégias de supressão de populações

    OpenAIRE

    André Barretto Bruno Wilke; Mauro Toledo Marrelli

    2012-01-01

    Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field u...

  16. Exploiting mosquito sugar feeding to detect mosquito-borne pathogens

    OpenAIRE

    Hall-mendelin, Sonja; Ritchie, Scott A.; Johansen, Cheryl A.; Zborowski, Paul; Cortis, Giles; Dandridge, Scott; Hall, Roy A.; Den Hurk, Andrew F.

    2010-01-01

    Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current...

  17. Spatial Heterogeneity, Host Movement and Mosquito-Borne Disease Transmission

    OpenAIRE

    Acevedo, Miguel A.; Prosper, Olivia; Lopiano, Kenneth; Ruktanonchai, Nick; Caughlin, T. Trevor; Martcheva, Maia; Osenberg, Craig W.; Smith, David L.

    2015-01-01

    Mosquito-borne diseases are a global health priority disproportionately affecting low-income populations in tropical and sub-tropical countries. These pathogens live in mosquitoes and hosts that interact in spatially heterogeneous environments where hosts move between regions of varying transmission intensity. Although there is increasing interest in the implications of spatial processes for mosquito-borne disease dynamics, most of our understanding derives from models that assume spatially h...

  18. Wolbachia-Associated Bacterial Protection in the Mosquito Aedes aegypti

    OpenAIRE

    Ye, Yixin H; WOOLFIT, MEGAN; Rancès, Edwige; O'Neill, Scott L; McGraw, Elizabeth A

    2013-01-01

    Wolbachia is a commonly occurring bacterium or symbiont that lives inside the cells of insects. Recently, Wolbachia was artificially introduced into the mosquito vector dengue virus that was naturally Wolbachia-free. Wolbachia limits the growth of a range of pathogens transmitted to humans, including viruses, bacteria and parasites inside the mosquito. This “pathogen protection” forms the basis of field trials to determine if releasing Wolbachia into wild mosquito populations could reduce...

  19. Advances in methods for colour marking of mosquitoes

    OpenAIRE

    Verhulst, N.O.; Loonen, J.A.C.M.; Takken, W.

    2013-01-01

    Background: Different techniques are available for colour marking insects and each technique may be suitable for different insect species. Mosquitoes can be marked to determine population size, distribution and flight distance or distinguish closely related species. In this study, two methods of colour marking mosquitoes were described in detail and the impact of both methods on the survival and host-seeking behaviour of the malaria mosquito Anopheles gambiae sensu stricto was investigated. M...

  20. Vector Competence of New Zealand Mosquitoes for Selected Arboviruses

    OpenAIRE

    Kramer, Laura D.; Chin, Pam; Cane, Rachel P.; Kauffman, Elizabeth B.; Mackereth, Graham

    2011-01-01

    New Zealand (NZ) historically has been free of arboviral activity with the exception of Whataroa virus (Togaviridae: Alphavirus), which is established in bird populations and is transmitted by local mosquitoes. This naive situation is threatened by global warming, invasive mosquitoes, and tourism. To determine the threat of selected medically important arboviruses to NZ, vector competence assays were conducted using field collected endemic and introduced mosquito species. Four alphaviruses (T...

  1. Evaluation of botanicals as repellents against mosquitoes

    OpenAIRE

    N G Das, I. Baruah

    2003-01-01

    Repellent properties of three plant extracts—essential oil (steam distillate) of Zanthoxylumlimonella (fruits), Citrus aurantifolia (leaf) and petroleum ether extract of Z. limonella (fruits)were evaluated as repellent against Aedes (S.) albopictus mosquitoes in mustard (Dhara) and coconut(Parachute) oil base under laboratory conditions. Three concentrations—10, 20 and 30% of therepellents were evaluated. Repellents in mustard oil afforded longer protection time against thebites of Aedes ...

  2. Crab Hole Mosquito Bluesâ??The Story

    Centers for Disease Control (CDC) Podcasts

    2011-05-12

    This podcast reports on a humorous song that takes a look at a very serious human and equine disease. Written and performed by the MARU Health Angels Band, Bill Dietz, director of the Division of Nutrition, Physical Activity and Obesity at CDC, talks about the song, "Crab Hole Mosquito Blues", and the history behind it.  Created: 5/12/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 5/23/2011.

  3. Climate change and mosquito-borne disease.

    OpenAIRE

    Reiter, P.

    2001-01-01

    Global atmospheric temperatures are presently in a warming phase that began 250--300 years ago. Speculations on the potential impact of continued warming on human health often focus on mosquito-borne diseases. Elementary models suggest that higher global temperatures will enhance their transmission rates and extend their geographic ranges. However, the histories of three such diseases--malaria, yellow fever, and dengue--reveal that climate has rarely been the principal determinant of their pr...

  4. Influence of biological and physicochemical characteristics of larval habitats on the body size of Anopheles gambiae mosquitoes (Diptera: Culicidae along the Kenyan coast

    Directory of Open Access Journals (Sweden)

    Joseph M. Mwangangi, Charles M. Mbogo, Ephantus J. Muturi, Joseph G. Nzovu, Ephantus W. Kabiru, John I. Githure, Robert J. Novak , John C. Beier

    2007-06-01

    Full Text Available Background & objectives: The number and productivity of larval habitats ultimately determine thedensity of adult mosquitoes. The biological and physicochemical conditions at the larval habitataffect larval development hence affecting the adult body size. The influence of biological and physicochemicalcharacteristics on the body size of Anopheles gambiae was assessed in Jaribuni village,Kilifi district along the Kenyan Coast.Methods: Ten cages measuring 1 × 1 × 1 m (1 m3 with a netting material were placed in 10 differentaquatic habitats, which were positive for anopheline mosquito larvae. Emergent mosquitoes werecollected daily by aspiration and the wing lengths were determined by microscopy. In the habitats,physicochemical parameters were assessed: pH, surface debris, algae and emergent plants, turbidity,substrate, nitrate, ammonia, phosphate and chlorophyll a content.Results: A total of 685 anopheline and culicine mosquitoes were collected from the emergent cages.Only female mosquitoes were considered in this study. Among the Anopheles spp, 202 were An.gambiae s.s., eight An. arabiensis, two An. funestus, whereas the Culex spp was composed of 214Cx. quinquefasciatus, 10 Cx. tigripes, eight Cx. annulioris and one Cx. cumminsii. The mean winglength of the female An. gambiae s.s. mosquitoes was 3.02 mm (n = 157, while that of An. arabiensiswas 3.09 mm (n = 9. There were no associations between the wing lengths and the environmentaland chemical parameters, except for a positive correlation between wing length of An. gambiae andchlorophyll a content (r = 0.622. The day on which the mosquitoes emerged was not significant forthe anopheline (p = 0.324 or culicine mosquitoes (p = 0.374, because the mosquito emerged fromthe cages on a daily basis.Interpretation & conclusion: In conclusion, there was variability in production of emergent mosquitoesfrom different habitats, which means that there should be targeted control on these habitatsbased on productivity.

  5. Forkhead transcription factors regulate mosquito reproduction.

    Science.gov (United States)

    Hansen, Immo A; Sieglaff, Douglas H; Munro, James B; Shiao, Shin-Hong; Cruz, Josefa; Lee, Iris W; Heraty, John M; Raikhel, Alexander S

    2007-09-01

    Forkhead-box (Fox) genes encode a family of transcription factors defined by a 'winged helix' DNA-binding domain. In this study we aimed to identify Fox factors that are expressed within the fat body of the yellow fever mosquito Aedes aegypti, and determine whether any of these are involved in the regulation of mosquito yolk protein gene expression. The Ae. aegypti genome contains 18 loci that encode putative Fox factors. Our stringent cladistic analysis has profound implications for the use of Fox genes as phylogenetic markers. Twelve Ae. aegypti Fox genes are expressed within various tissues of adult females, six of which are expressed within the fat body. All six Fox genes expressed in the fat body displayed dynamic expression profiles following a blood meal. We knocked down the 'fat body Foxes' through RNAi to determine whether these 'knockdowns' hindered amino acid-induced vitellogenin gene expression. We also determined the effect of these knockdowns on the number of eggs deposited following a blood meal. Knockdown of FoxN1, FoxN2, FoxL, and FoxO, had a negative effect on amino acid-induced vitellogenin gene expression and resulted in significantly fewer eggs laid. Our analysis stresses the importance of Fox transcription factors in regulating mosquito reproduction. PMID:17681238

  6. Manipulating insulin signaling to enhance mosquito reproduction

    Directory of Open Access Journals (Sweden)

    Rasgon Jason L

    2009-08-01

    Full Text Available Abstract Backgrond In the mosquito Aedes aegypti the insulin/insulin growth factor I signaling (IIS cascade is a key regulator of many physiological processes, including reproduction. Two important reproductive events, steroidogenesis in the ovary and yolk synthesis in the fat body, are regulated by the IIS cascade in mosquitoes. The signaling molecule phosphatase and tensin homolog (PTEN is a key inhibitor of the IIS cascade that helps modulate the activity of the IIS cascade. In Ae. aegypti, six unique splice variants of AaegPTEN were previously identified, but the role of these splice variants, particularly AaegPTEN3 and 6, were unknown. Results Knockdown of AaegPTEN or its specific splice variant AaegPTEN6 (the splice variant thought to regulate reproduction in the ovary and fat body using RNAi led to a 15–63% increase in egg production with no adverse effects on egg viability during the first reproductive cycle. Knockdown of AaegPTEN3, expressed predominantly in the head, had no effect on reproduction. We also characterized the protein expression patterns of these two splice variants during development and in various tissues during a reproductive cycle. Conclusion Previous studies in a range of organisms, including Drosophila melanogaster and Caenorhabditis elegans, have demonstrated that disruption of the IIS cascade leads to decreased reproduction or sterility. In this study we demonstrate that knockdown of the IIS inhibitor PTEN can actually increase reproduction in the mosquito, at least during the first reproductive cycle.

  7. Lista dos mosquitos da Bolívia: (Diptera, Culicidae

    Directory of Open Access Journals (Sweden)

    N. L. Cerqueira

    1943-08-01

    Full Text Available Em quinze gêneros, cento e vinte e seis espécies de mosquitos foram constatadas no material capturado pelo Servicio de Fiebre Amarilla desde 1933 até 1942. Êste número, três vezes mais elevado do que o existente na literatura para o país, seria ainda maior se possível fôsse identificar sem o auxílio de machos inúmeras fêmeas das espécies de Culex. Tôdas as espécies estudadas apresentavam suas distribuições geográficas nos departamentos e províncias onde casos de Febre Amarela foram observados. Algumas cosiderações foram feitas em torno de espécies que não correspondiam exatamente com as descrições existentes, assim como descrições de outras foram dadas, cujos sexos opostos apenas eram conhecidos.One hundred and twenty-six species of mosquitoes, corresponding fifteen genera, have been found in material collected by the Bolivian Yellow Fever Service between 1933 and 1942. This number is three times that given for the country in existing literature and would be even largar if it were possible to identify a consierable group of Culex mosquitoes composed principally of female specimens. All species studied come from Departmetns and Provinces where cases of yellow fever have been found. Consideration has been given to certain species which do not agree exactly with existing descriptions, and supplementary descriptions have been made for the male or female of two additional species for which only description of the opposite sex had existed.

  8. Efectividad y supervivencia de Romanomermis culicivorax en criaderos naturales de larvas de mosquitos / Effectiveness and survival of Romanomermis culicivorax in natural breeding sites of mosquito larvae

    Scientific Electronic Library Online (English)

    Rafael, Pérez-Pacheco; Alberto, Santamarina-Mijares; Alfonso, Vásquez-López; Sabino H., Martínez-Tomás; Javier, Suárez-Espinosa.

    2009-12-01

    Full Text Available Los mosquitos (Díptera: Culicidae) son transmisores de agentes causales de paludismo, dengue y encefalitis del Nilo occidental y causan fuertes molestias a los humanos. El objetivo del presente estudio fue determinar el efecto de aplicar 500 y 1000 nemátodos, Romanomermis culicivorax Ross y Smith, p [...] or metro cuadrado en poblaciones de larvas de Anopheles albimanus Wiedeman, Culex nigipalpus Theobald y Uranotaenia sapphirina Oster-Sacken, para su control en 13 criaderos naturales. El diseño experimental fue completamente al azar con arreglo factorial de dos factores (dos dosis de nemátodos y tres especies de mosquitos). La dosis de 500 nemátodos causó 74.3-87.8 % de parasitismo en larvas de las tres especies; la dosis de 1000 causó 77.2-96.9 % de parasitismo, con un incremento del parasitismo al aumentar la dosis de nemátodos (p Abstract in english Mosquitoes (Díptera: Culicidae) transmit causal agents of malaria, dengue and western Nile encephalitis, besides being extremely annoying for humans. The objective of this study was to determine the control effect of releasing 500 and 1000 Romanomermis culicivorax Ross and Smith nematodes per square [...] meter into larval populations of Anopheles albimanus Wiedeman, Culex nigripalpus Theobald, and Uranotenia sapphiriuna Oster-Sacken in 13 natural breeding sites. The experimental design was completely randomized with a factorial arrangement of two factors (two dosages of nematodes and three species of mosquitoes). The doses of 500 nematodes m-2 caused 74.3-87.8 % parasitism in larvae of the three species; the dose of 1000 nematodes m-2 caused 77.2-96.9 % parasitism; that is, parasitism was higher with the higher dose of nematodes (p

  9. Venereal Transmission of Chikungunya Virus by Aedes aegypti Mosquitoes (Diptera: Culicidae)

    OpenAIRE

    Mavale, Mangala; Parashar, Deepti; Sudeep, Anakkathil; Gokhale, Mangesh; Ghodke, Youwaraj; Geevarghese, Geevarghese; Arankalle, Vidya; Mishra, Akhilesh Chandra

    2010-01-01

    Experiments were conducted to demonstrate the role of male Aedes aegypti mosquitoes in the maintenance and transmission of chikungunya virus (CHIKV) to female mosquitoes. We demonstrated that infected male mosquitoes are capable of infecting females during mating. The infection rate in female mosquitoes was 11% when virgin female mosquitoes were allowed to coinhabit with infected males. The body suspension of venereally infected female mosquitoes induced illness in infant Swiss albino mice, w...

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

    Scientific Electronic Library Online (English)

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

    2014-08-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2014-08-01

    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

  12. Evaluation of organophosphorus and synthetic pyrethroid insecticides against six vector mosquitoe species Avaliação de inseticidas organofosforados e piretroides sintéticos contra seis mosquitos vetores

    Directory of Open Access Journals (Sweden)

    Domingo Montada Dorta

    1993-12-01

    Full Text Available Three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquitoe species: Culex quinquefasciatus (Filariasis and Aedes albopictus (Dengue (both laboratory and field strains; laboratory strains of Aedes aegypti (Dengue, Anopheles slephensi and Anopheles culicifacies (Malaria, and Culex tritaeniorhynchus (Japanese encephalitis in India. From the LC50 values obtained for these insecticides, it was found that all mosquito species including the field strains of Cx. quinquefasciatus and Ae. albopictus were highly susceptible Except for Cx. quinquefasciatus (field strain against malathion, 100% mortality was observed at the discriminating dosages recommended by World Health Organization. The residual effect of alphamethrin, deltamethrin, malathion and folithion at 25 mg (ai/m² on different surfaces against six species of vector mosquitoes showed that alphamethrin was the most effective on all four treated surfaces (mud, plywood, cement and thatch. Nevertheless, residual efficacy lasted longer on thatch than on the other surfaces. Therefore, synthetic pyrethroids such as alphamethrin can be effectively employed in integrated vector control operations.Três compostos organo-fosforados - malation, folition e temefos -e dois piretroides sintéticos - alfametrina e deltametrina - foram usados para controlar o estado da susceptibilidade das larvas e adultos de seis mosquitos vetores na Índia. Foram utilizadas cepas de laboratório e área de Culex quinquefasciatus (filariasis e Aedes albopictus (Dengue e cepas de laboratório de Aedes aegypti (Dengue, Anopheles stephensi e Anopheles culicifacies (Malária e Culex tritaenorhynchus (encefalite japonesa. Os valores de C1(50 obtidos para esses inseticidas mostram que todas as espécies incluindo as cepas de área foram muito susceptíveis. Nos mosquitos adultos das referidas espécies salvo na cepa da área de Culex quinquefasciatus com o malathion, observou-se 100% da mortalidade às doses discriminatórias recomendadas pela Organização Mundial de Saúde. O efeito residual da alfametrina, deltametrina, malation e folition a 25 mg (ai/m² em diversas superfícies contra seis espécies de mosquitos vetores evidenciou que a alfametrina foi a mais efetiva em todas as superfícies tratadas (argila, "plywood", cimento e palha.

  13. Evaporation and skin penetration characteristics of mosquito repellent formulations

    International Nuclear Information System (INIS)

    Formulations of the mosquito repellent N,N-diethyl-3-methylbenzamide (deet) in combination with a variety of additives were developed to control repellent evaporation and percutaneous penetration. Deet was also formulated with the repellent dimethyl phthalate to study the interaction of the two compounds on the skin. The evaporation and penetration processes were evaluated on whole and split-thickness pig skin using radiolabeled repellents with an in vitro apparatus. Under essentially still air and air flow conditions, one of the deet formulations resulted in significantly reduced total evaporation and percutaneous penetration of deet as compared to unformulated repellent. When deet and dimethyl phthalate were combined, neither repellent affected the total amount of evaporation and penetration of the other compound. However, initial percutaneous penetration and evaporation rates were slightly less and decayed less rapidly than when both chemicals were tested separately at the same dose. These results indicated a degree of competition of the two compounds for the same avenues of loss

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

    Science.gov (United States)

    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

  15. Evaluation of selected South African ethnomedicinal plants as mosquito repellents against the Anopheles arabiensis mosquito in a rodent model

    OpenAIRE

    Folb Peter I; Bhagwandin Niresh; Newmarch Marion; Crouch Neil R; Maharaj Vinesh; Maharaj Rajendra; Pillay Pamisha; Gayaram Reshma

    2010-01-01

    Abstract Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic), that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito repellent properties. Methods Extracts of a selection of South African taxa were tested for repellency properties in an applicable mosquito feeding-probing assay using unfed female Anopheles arabiensis. Results Although a water extract of the roots of Chenopodiu...

  16. Rift Valley Fever Virus (RVFv) Dissemination inside Mosquitoes and Investigation of the Influence of Climate on Mosquitoes Abundance

    OpenAIRE

    Rania Ali El Hadi Mohamed; Emadeldin Hassan Konozy; El Amin El Rayah

    2013-01-01

    One year surveys were conducted at two sites in Khartoum State capital of Sudan: Hellat Kuku and Soba West. The study was focused into two species of mosquitoes: Aedes vexans and Culex quinquefasciatus. This selection was based on previous investigations indicated their being positive for RVF. The study aimed to investigate on RVFv dissemination inside two species mosquitoes in Khartoum State (Sudan) and investigation of the influence of climate on mosquitoes abundance. Weekly aspiration of w...

  17. Effects of open marsh water management on numbers of larval salt marsh mosquitoes

    Science.gov (United States)

    James-Pirri, Mary-Jane; Ginsberg, Howard S.; Erwin, R. Michael; Taylor, Janith

    2009-01-01

    Open marsh water management (OMWM) is a commonly used approach to manage salt marsh mosquitoes than can obviate the need for pesticide application and at the same time, partially restore natural functions of grid-ditched marshes. OMWM includes a variety of hydrologic manipulations, often tailored to the specific conditions on individual marshes, so the overall effectiveness of this approach is difficult to assess. Here, we report the results of controlled field trials to assess the effects of two approaches to OMWM on larval mosquito production at National Wildlife Refuges (NWR). A traditional OMWM approach, using pond construction and radial ditches was used at Edwin B. Forsythe NWR in New Jersey, and a ditch-plugging approach was used at Parker River NWR in Massachusetts. Mosquito larvae were sampled from randomly placed stations on paired treatment and control marshes at each refuge. The proportion of sampling stations that were wet declined after OMWM at the Forsythe site, but not at the Parker River site. The proportion of samples with larvae present and mean larval densities, declined significantly at the treatment sites on both refuges relative to the control marshes. Percentage of control for the 2 yr posttreatment, compared with the 2 yr pretreatment, was >90% at both treatment sites.

  18. Larvicidal activity of methanolic leaf extracts of plant, Chromolaena odorata L. (Asteraceae against vector mosquitoes

    Directory of Open Access Journals (Sweden)

    Jagruti H. Sukhthankar

    2014-09-01

    Full Text Available Mosquitoes transmit malaria, filariasis, dengue, chikungunya, etc. Repeated use of insecticides for mosquito control has caused development of resistance, adverse effects on non-target organisms and serious environmental concerns. Hence alternative control measures are being explored inter alia plant based insecticides. We carried out larvicidal bioassays with methanolic extract of leaves of Chromolaena odorata (family Asteraceae against late instar larvae of disease vectors Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The highest mortality was observed in Cx. quinquefasciatus [LC50 = 43 ppm, (95% CI: 34 - 48 ppm; LC90 = 110 ppm (CI: 94 - 135 ppm] followed by Ae. aegypti [LC50 = 138 ppm, (CI: 121 - 157 ppm; LC90 = 463 ppm (CI: 386 - 584 ppm] and An. stephensi [LC50 = 1613 ppm (CI: 1364 - 1890 ppm; LC90 = 8306 ppm (CI: 6598 - 11076 ppm]. Being larvicidal, leaf extracts of Chromolaena odorata could be explored further.

  19. Ethical, social, and cultural considerations for site selection for research with genetically modified mosquitoes.

    Science.gov (United States)

    Lavery, James V; Harrington, Laura C; Scott, Thomas W

    2008-09-01

    Recent advances in technology have made strategies for disease control using genetically modified (GM) vectors more plausible. Selecting an appropriate field site for research with GM mosquitoes may be one of the most complex and significant aspects of the research process. Among the key considerations of the process is the need to address ethical, legal, and cultural (ESC) issues. No guidelines have been developed to date for this complicated and sensitive process. In this paper, we describe a site selection process and a set of preliminary considerations for addressing the ESC aspects of a research program involving genetic strategies for the control of mosquitoes as vectors for dengue viruses. These considerations reflect some of the key ESC issues for site selection decisions for research with GM vectors. PMID:18784220

  20. St. Louis Encephalitis virus mosquito vectors dynamics in three different environments in relation to remotely sensed environmental conditions.

    Science.gov (United States)

    Batallán, Gonzalo P; Estallo, Elizabet L; Flores, Fernando S; Sartor, Paolo; Contigiani, Marta S; Almirón, Walter R

    2015-06-01

    In Argentina the St. Louis Encephalitis virus (SLEV) is an endemic and widely distributed pathogen transmitted by the cosmopolitan mosquito Culex quinquefasciatus. During two outbreaks in Córdoba city, in 2005 and 2010, Culex interfor was also found infected, but its role as vector of SLEV is poorly known. This mosquito species is distributed from central Argentina to southern Brazil. The primary aim of this study was to analyze the population dynamic of Cx. interfor and Cx. quinquefasciatus in three different environments (urban, suburban and non-urban) in relation to remotely sensed environmental data for vegetation (NDVI and NDWI) and temperature (brightness temperature). Cx. quinquefasciatus and Cx. interfor were found at the three sampled sites, being both the most abundant Culex species, with peaks in early and midsummer. Temporal distribution patterns of both mosquito species were highly correlated in a non-urban area of high SLEV risk transmission. Cx. quinquefasciatus and Cx. interfor were associated with the most urbanized site and the non-urban environment, respectively; high significant correlations were detected between vegetation indices and abundance of both mosquito species confirming these associations. These data provide a foundation for building density maps of these two SLEV mosquito vectors using remotely sensed data to help inform vector control programs. PMID:25792419

  1. Assessing the efficacy of candidate mosquito repellents against the background of an attractive source that mimics a human host.

    Science.gov (United States)

    Menger, D J; Van Loon, J J A; Takken, W

    2014-12-01

    Mosquito repellents are used around the globe to protect against nuisance biting and disease-transmitting mosquitoes. Recently, there has been renewed interest in the development of repellents as tools to control the transmission of mosquito-borne diseases. We present a new bioassay for the accurate assessment of candidate repellent compounds, using a synthetic odour that mimics the odour blend released by human skin. Using DEET (N,N-diethyl-meta-toluamide) and PMD (p-menthane-3,8-diol) as reference compounds, nine candidate repellents were tested, of which five showed significant repellency to the malaria mosquito Anopheles gambiae sensu stricto (Diptera: Culicidae). These included: 2-nonanone; 6-methyl-5-hepten-2-one; linalool; ?-decalactone, and ?-undecalactone. The lactones were also tested on the yellow fever mosquito Aedes aegypti (Stegomyia aegypti) (Diptera: Culicidae), against which they showed similar degrees of repellency. We conclude that the lactones are highly promising repellents, particularly because these compounds are pleasant-smelling, natural products that are also present in human food sources. PMID:24797537

  2. An Educational Interventional Study to Assess Awareness about Mosquito Breeding, Diseases Caused and Protective Measures Against them among Families Residing in an Urban Slum of Indore City

    Directory of Open Access Journals (Sweden)

    Deepa Raghunath

    2013-08-01

    Full Text Available Background: Community participation plays an important role in control of Mosquito borne diseases. This study tries to assess impact of educational intervention on various aspects of mosquito borne diseases in an urban slum. Methodology: An educational interventional study was done in 200 families residing in a slum (Badi Gwaltoli which is in field practice area of Urban Health Centre attached to Department of Community Medicine of M.G.M.Medical College, Indore. A pretested semi-structured questionnaire was administered to the Head of the family which studied their awareness and perception regarding breeding sites and biting habits of mosquitoes, diseases spread by them and personal protective measures used, followed by an educational intervention and post assessment. Data was entered into Microsoft excel spread sheet and analysed using SPSS version 20 software. Results: 46% of study population knew the correct breeding season of mosquitoes (monsoon season during pre-intervention and 68% of the population post- intervention (p- value 0.004. When asked at what time mosquitoes bite the most, maximum number (92% of people said that mosquitoes bite most in the evening and night, while only 6% and 2% were for morning and noon, respectively. Only 3.5% of the population who knew about breeding sites knew about artificial collections of water. Majority said mosquito breed in dirty stagnant water (78.5%. About 96%of the study population was aware that mosquitoes spread diseases. However, only 33.3%of respondents knew correctly about the diseases spread which improved to 68% in the post-intervention period (p-value=.000. 46% knew all the protection measures against mosquitoes in the pre-intervention which increased to 86% in the post intervention (p.value-.005. Conclusion: Awareness about Aedes mosquitoes and its habits is quite poor and many people still believe that only dirty water serves as a breeding place in mosquitoes. Regular IEC sessions informing community about mosquito-borne diseases will improve community participation.

  3. Effect of Mosquito Repellent on the Transmission Model of Chikungunya Fever

    OpenAIRE

    Surapol Naowarat; Prasit Thongjaem; Tang, I. M.

    2012-01-01

    Problem statement: In 2008 there was a large outbreak of Chikungunya fever in southern Thailand. Chikungunya fever is an emerging disease which tends to affect rubber plantation and fruit orchard workers more than other occupation. This study we considers the efficacy of using mosquito repellent as a way to prevent and control the spread of Chikungunya fever. The mathematical model of the dynamic of this disease is proposed and analyzed. Approach: A standard dynamical modeling method was appl...

  4. The distribution and bionomics of anopheles malaria vector mosquitoes in Indonesia.

    OpenAIRE

    Elyazar, Ir; Sinka, Me; Gething, Pw; Tarmidzi, Sn; Surya, A.; Kusriastuti, R.; Baird, Jk; Hay, SI; Bangs, Mj

    2013-01-01

    Malaria remains one of the greatest human health burdens in Indonesia. Although Indonesia has a long and renowned history in the early research and discoveries of malaria and subsequently in the successful use of environmental control methods to combat the vector, much remains unknown about many of these mosquito species. There are also significant gaps in the existing knowledge on the transmission epidemiology of malaria, most notably in the highly malarious eastern half of the archipelago. ...

  5. Distributions of Competing Container Mosquitoes Depend on Detritus Types, Nutrient Ratios, and Food Availability

    OpenAIRE

    Murrell, Ebony G.; Damal, Kavitha; Lounibos, L. P.; Juliano, Steven A.

    2011-01-01

    Coexistence of competitors may result if resources are sufficiently abundant to render competition unimportant, or if species differ in resource requirements. Detritus type has been shown to affect interspecific competitive outcomes between Aedes albopictus (Skuse) and Aedes aegypti (L.) larvae under controlled conditions. We assessed the relationships among spatial distributions of detritus types, nutrients, and aquatic larvae of these species in nature. We collected mosquitoes, water, and d...

  6. Evaluation of textile substrates for dispensing synthetic attractants for malaria mosquitoes

    OpenAIRE

    Mweresa, C. K.; Mukabana, W. R.; Omusula, P.; Otieno, B.; Gheysens, G.; Takken, W.; Loon, J. J. A.

    2014-01-01

    Background The full-scale impact of odour-baited technology on the surveillance, sampling and control of vectors of infectious diseases is partly limited by the lack of methods for the efficient and sustainable dispensing of attractants. In this study we investigated whether locally-available and commonly used textiles are efficient substrates for the release of synthetic odorant blends attracting malaria mosquitoes. Methods The relative efficacy of (a) polyester, (b) cotton, (c) cellulose?...

  7. Uncontrolled seizures and unusual rise in leucocyte counts: transfluthrin, liquid mosquito repellent suicidal poisoning.

    Science.gov (United States)

    Shringi, Kiran Lata; Dulara, Sc; Aseri, Rk; Daria, Usha

    2015-01-01

    Transfluthrin is being used as fast acting insecticide and liquid mosquito repellent. This is a case report of poisoning with transfluthrin (90 ml liquid containing 792 mg of transfluthrin) by a 25-year-old female. Tonic-clonic convulsions were not controlled with conventional drugs. In intensive care unit, patient was managed with muscle paralysis by neuromuscular blocking drug vecuronium and elective mechanical ventilation for more than 48 h under care of the anaesthesiologist with uneventful recovery. PMID:25684814

  8. Ultraviolet light sensitivity, unscheduled DNA synthesis and DNA repair in C7-10 Aedes albopictus mosquito cells.

    Science.gov (United States)

    Jayachandran, G; Fallon, A M.

    2002-01-01

    We have examined the relative sensitivity of Aedes albopictus C7-10 mosquito cells to irradiation with ultraviolet light from a germicidal lamp. On the basis of plating efficiency, C7-10 cells were approximately two times more resistant to UV light than human 293 leukemia cells. Recovery after UV irradiation was accompanied by an increase in unscheduled DNA synthesis (UDS), which was measured by incorporation of (3)H-thymidine into acid-precipitable DNA in the presence of hydroxyurea. Under standardized conditions, UDS was maximal after a 10 min exposure (120 J/m(2)), and declined after longer exposures. In addition, UV treatment is associated with a small but reproducible increase in repair of plasmid DNA in transiently transfected cells. We anticipate that analysis of DNA repair activities in mosquito cells will identify molecular targets that might control longevity in transgenic mosquitoes. PMID:12770140

  9. MOSQUITO MAGNETS AS BARRIER TREATMENTS AGAINST SALT MARSH MOSQUITOES AROUND RESIDENTIAL HOUSES IN MARSH AREA

    Science.gov (United States)

    In recent years, more residential homes have been built around the marsh areas located on the Intra-Coastal Waterway (ICW) and brought more complaints about marsh mosquitoes. Many homeowner associations have created policies and regulations that forbid the spraying of pesticides. The new challenge h...

  10. ATTRACTION OF CULEX MOSQUITOES TO COMPOUNDS IDENTIFIED FROM BIRDS

    Science.gov (United States)

    Although birds play a critical role in the maintenance and amplification of mosquito populations and as reservoirs of disease, little is known about the cues used by mosquitoes to locate birds. Most attractants for traps have been developed for anthropophilic species such as Aedes aegypti using cue...

  11. Isolation and Molecular Characterization of Banna Virus from Mosquitoes, Vietnam

    OpenAIRE

    Nabeshima, Takeshi; Nga, Phan Thi; Guillermo, Posadas; Del Carmen Parquet, Maria; Yu, Fuxun; Thuy, Nguyen Thanh; Trang, Bui Minh; Hien, Nguyen Tran; Nam, Vu Sinh; Inoue, Shingo; Hasebe, Futoshi; Morita, Kouichi

    2008-01-01

    We isolated and characterized a Banna virus from mosquitoes in Vietnam; 5 strains were isolated from field-caught mosquitoes at various locations; Banna virus was previously isolated from encephalitis patients in Yunnan, China, in 1987. Together, these findings suggest widespread distribution of this virus throughout Southeast Asia.

  12. Toxicity of Bacillus sphaericus crystal toxin to adult mosquitoes.

    OpenAIRE

    Stray, J E; Klowden, M J; Hurlbert, R. E.

    1988-01-01

    Adult Culex quinquefasciatus mosquitoes were killed by alkaline-solubilized Bacillus sphaericus toxin when it was introduced by enema into the midgut of the insect but not when it was administered orally. Adult Aedes aegypti mosquitoes were not affected by the toxin.

  13. Aedes aegypti Mosquitoes Imported into the Netherlands, 2010

    OpenAIRE

    BROWN, JULIA E.; Scholte, Ernst-Jan; Dik, Marian; Den Hartog, Wietse; Beeuwkes, Jacob; POWELL, JEFFREY R.

    2011-01-01

    During summer 2010, Aedes aegypti mosquitoes were discovered in the Netherlands. Using genetic markers, we tracked the origin of these mosquitoes to a tire shipment from Miami, Florida, USA. Surveillance of tire exports from the United States should be included as part of a comprehensive surveillance system.

  14. Protocol for RNAi Assays in Adult Mosquitoes (A. gambiae)

    OpenAIRE

    Garver, Lindsey; Dimopoulos, George

    2007-01-01

    Reverse genetic approaches have proven extremely useful for determining which genes underly resistance to vector pathogens in mosquitoes. This video protocol illustrates a method used by the Dimopoulos lab to inject dsRNA into Anopheles gambiae mosquitoes, which harbor the malaria parasite. The technique manipulating the injection setup and injecting dsRNA into the thorax is illustrated.

  15. Malaria Situation and Anopheline Mosquitoes in Qom Province, Central Iran

    Directory of Open Access Journals (Sweden)

    MR Abai

    2010-12-01

    Full Text Available "nAbstract "nBackground: The aims of this study was to analysis the current situation of malaria and to find the distribution of anopheline mosquitoes, as probable vectors of the disease, in Qom Province, central Iran. "nMethods: This study was carried out in two parts. First stage was data collection about malaria cases using recorded documents of patients in the Province health center, during 2001–2008. The second stage was entomological survey conducted by mosquito larval collection method in 4 villages with different geographical positions in 2008. Data were analyzed using Excel software. "nResults: Of 4456 blood slides, 10.9% out were positive. Most of cases were imported from other countries (90.4%, mainly from Afghanistan (56.5% and Pakistan (16.3%. Slide positive rate showed a maximum of 16.9% and a minimum of 2.9% in 2008 and 2007, respectively. Plasmodium vivax was causative agent of 93.75% of cases, fol­lowed by P. falciparum (6.25%. More than 15 years old age group contained the most malaria reported cases (66.7%. Two Anopheles species, An. superpictus and An. claviger were collected and identified. This is the first report of Anopheles claviger in Qom Province. "nConclusion: Malaria is in the control stage in Qom Province. The rate of local transmission is very low (only 1 case, shows Anopheles superpictus, as the main malaria vector of central part of Iran, can play its role in malaria transmission in the area. "n  "nKeywords: Malaria, Iran, Epidemiology

  16. Mosquito transmission of the rodent malaria parasite Plasmodium chabaudi

    Directory of Open Access Journals (Sweden)

    Spence Philip J

    2012-12-01

    Full Text Available Abstract Background Serial blood passage of Plasmodium increases virulence, whilst mosquito transmission inherently regulates parasite virulence within the mammalian host. It is, therefore, imperative that all aspects of experimental malaria research are studied in the context of the complete Plasmodium life cycle. Methods Plasmodium chabaudi chabaudi displays many characteristics associated with human Plasmodium infection of natural mosquito vectors and the mammalian host, and thus provides a unique opportunity to study the pathogenesis of malaria in a single infection setting. An optimized protocol that permits efficient and reproducible vector transmission of P. c. chabaudi via Anopheles stephensi was developed. Results and conclusions This protocol was utilized for mosquito transmission of genetically distinct P. c. chabaudi isolates, highlighting differential parasite virulence within the mosquito vector and the spectrum of host susceptibility to infection initiated via the natural route, mosquito bite. An apposite experimental system in which to delineate the pathogenesis of malaria is described in detail.

  17. How Mosquitoes Can Fly in the Rain

    Science.gov (United States)

    MIT BLOSSOMS

    2012-10-29

    In this lesson, we learn how insects can fly in the rain. The objective is to calculate the impact forces of raindrops on flying mosquitoes. Students will gain experience with using Newton's laws, gathering data from videos and graphs, and most importantly, the utility of making approximations. No calculus will be used in this lesson, but familiarity with torque and force balances is suggested. No calculators will be needed, but students should have pencil and paper to make estimations and, if possible, copies of the graphs provided with the lesson. Between lessons, students are recommended to discuss the assignments with their neighbors.

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

    Science.gov (United States)

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

    2015-03-01

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

  19. Analysis and optimization of a synthetic milkweed floral attractant for mosquitoes.

    Science.gov (United States)

    Otienoburu, Philip E; Ebrahimi, Babak; Phelan, P Larry; Foster, Woodbridge A

    2012-07-01

    A pentane extract of flowers of common milkweed, Asclepias syriaca (Asclepiadaceae), elicited significant orientation from both male and female Culex pipiens in a dual-port flight olfactometer. Analysis of the extract by gas chromatography-mass spectrometry revealed six major constituents in order of relative abundance: benzaldehyde, (E)-?-ocimene, phenylacetaldehyde, benzyl alcohol, nonanal, and (E)-2-nonenal. Although not all were collected from the headspace profile of live flowers, a synthetic blend of these six compounds, when presented to mosquitoes in the same levels and proportions that occur in the extract, elicited a response comparable to the extract. Subtractive behavioral bioassays demonstrated that a three-component blend consisting of benzaldehyde, phenylacetaldehyde, and (E)-2-nonenal was as attractive as the full blend. These findings suggest the potential use of synthetic floral-odor blends for monitoring or control of both male and female disease-vectoring mosquitoes. PMID:22711028

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

    Science.gov (United States)

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

    2011-08-01

    Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. In mosquito control programs, botanical origin may have the potential to be used successfully as eggs, larvae, and adult. The larvicidal, ovicidal, and repellent activities of crude benzene and ethyl acetate extracts of leaf of Ervatamia coronaria and Caesalpinia pulcherrima were assayed for their toxicity against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in benzene extract of E. coronaria against the larvae of Anopheles Stephensi, Aedes aegypti, and Culex quinquefasciatus with the LC(50) and LC(90) values were 79.08, 89.59, and 96.15 ppm and 150.47, 166.04, and 174.10 ppm, respectively. Mean percent hatchability of the ovicidal activity was observed 48 h posttreatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. The leaf extract of E. coronaria was found to be most effective than Caesalpinia pulcherrima against eggs/egg rafts of three vector mosquitoes. For E. coronaria, the benzene extract exerted 300, 250, and 200 ppm against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, respectively. The results of the repellent activity of benzene and ethyl acetate extract of E. coronaria and Caesalpinia pulcherrima plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm(2) were applied on skin of fore arm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf solvent plant extracts have the potential to be used as an ideal ecofriendly approach for the control of mosquitoes. This is the first report on the mosquito larvicidal, ovicidal, and repellent activities of the reported E. coronaria and Caesalpinia pulcherrima plants. PMID:21318385

  1. Molecular evidence for dual pyrethroid-receptor sites on a mosquito sodium channel.

    Science.gov (United States)

    Du, Yuzhe; Nomura, Yoshiko; Satar, Gul; Hu, Zhaonong; Nauen, Ralf; He, Sheng Yang; Zhorov, Boris S; Dong, Ke

    2013-07-16

    Pyrethroid insecticides are widely used as one of the most effective control measures in the global fight against agricultural arthropod pests and mosquito-borne diseases, including malaria and dengue. They exert toxic effects by altering the function of voltage-gated sodium channels, which are essential for proper electrical signaling in the nervous system. A major threat to the sustained use of pyrethroids for vector control is the emergence of mosquito resistance to pyrethroids worldwide. Here, we report the successful expression of a sodium channel, AaNav1-1, from Aedes aegypti in Xenopus oocytes, and the functional examination of nine sodium channel mutations that are associated with pyrethroid resistance in various Ae. aegypti and Anopheles gambiae populations around the world. Our analysis shows that five of the nine mutations reduce AaNav1-1 sensitivity to pyrethroids. Computer modeling and further mutational analysis revealed a surprising finding: Although two of the five confirmed mutations map to a previously proposed pyrethroid-receptor site in the house fly sodium channel, the other three mutations are mapped to a second receptor site. Discovery of this second putative receptor site provides a dual-receptor paradigm that could explain much of the molecular mechanisms of pyrethroid action and resistance as well as the high selectivity of pyrethroids on insect vs. mammalian sodium channels. Results from this study could impact future prediction and monitoring of pyrethroid resistance in mosquitoes and other arthropod pests and disease vectors. PMID:23821746

  2. Modeling Future Conservation of Hawaiian Honeycreepers by Mosquito Management and Translocation of Disease-Tolerant Amakihi

    Science.gov (United States)

    Hobbelen, Peter H. F.; Samuel, Michael D.; LaPointe, Dennis A.; Atkinson, Carter T.

    2012-01-01

    Avian malaria is an important cause of the decline of endemic Hawaiian honeycreepers. Because of the complexity of this disease system we used a computer model of avian malaria in forest birds to evaluate how two proposed conservation strategies: 1) reduction of habitat for mosquito larvae and 2) establishment of a low-elevation, malaria-tolerant honeycreeper (Hawaii Amakihi) to mid-elevation forests would affect native Hawaiian honeycreeper populations. We evaluated these approaches in mid-elevation forests, where malaria transmission is seasonal and control strategies are more likely to work. Our model suggests the potential benefit of larval habitat reduction depends on the level of malaria transmission, abundance of larval cavities, and the ability to substantially reduce these cavities. Permanent reduction in larval habitat of >80% may be needed to control abundance of infectious mosquitoes and benefit bird populations. Establishment of malaria-tolerant Amakihi in mid-elevation forests increases Amakihi abundance, creates a larger disease reservoir, and increases the abundance of infectious mosquitoes which may negatively impact other honeycreepers. For mid-elevation sites where bird populations are severely affected by avian malaria, malaria-tolerant Amakihi had little impact on other honeycreepers. Both management strategies may benefit native Hawaiian honeycreepers, but benefits depend on specific forest characteristics, the amount of reduction in larval habitat that can be achieved, and how malaria transmission is affected by temperature. PMID:23185375

  3. Pesticide susceptibility status of Anopheles mosquitoes in four flood-affected districts of South Punjab, Pakistan.

    Science.gov (United States)

    Rathor, Hamayun Rashid; Nadeem, Ghazala; Khan, Imtinan Akram

    2013-01-01

    Recent floods drastically increased the burden of disease, in particular the incidence of malaria, in the southern districts of the Punjab province in Pakistan. Control of malaria vector mosquitoes in these districts requires the adoption of an appropriate evidence-based policy on the use of pesticides, and having the latest information on the insecticide resistance status of malaria vector mosquitoes is essential for designing effective disease prevention policy. Using World Health Organization (WHO) test kits, the present study utilized papers impregnated with DDT, malathion, deltamethrin, lambda-cyhalothrin, and permethrin, to determine the insecticide susceptibility/resistance status of malaria vector mosquitoes in four flood-affected districts. The test results showed that both Anopheles stephensi and Anopheles culicifacies remained resistant to DDT and malathion. Tests with three commonly used pyrethroids, permethrin, lambda-cyhalothrin, and deltamethrin, detected resistance in the majority of cases, but in a number of localities mortalities with these three pyrethroids ranged from 80-97% and were therefore placed under verification-required status. This status indicates the presence of susceptible individuals in these populations. These results suggest that if appropriate resistance management strategies are applied in these areas, then the development of high levels of resistance can still be prevented or slowed. This study forms an important evidence base for the strategic planning of vector control in the four flood-affected districts. PMID:23199276

  4. Mosquito abundance, bed net coverage and other factors associated with variations in sporozoite infectivity rates in four villages of rural Tanzania

    Directory of Open Access Journals (Sweden)

    Kweka Eliningaya J

    2008-04-01

    Full Text Available Abstract Background Entomological surveys are of great importance in decision-making processes regarding malaria control strategies because they help to identify associations between vector abundance both species-specific ecology and disease intervention factors associated with malaria transmission. Sporozoite infectivity rates, mosquito host blood meal source, bed net coverage and mosquito abundance were assessed in this study. Methodology A longitudinal survey was conducted in four villages in two regions of Tanzania. Malaria vectors were sampled using the CDC light trap and pyrethrum spray catch methods. In each village, ten paired houses were selected for mosquitoes sampling. Sampling was done in fortnight case and study was undertaken for six months in both Kilimanjaro (Northern Tanzania and Dodoma (Central Tanzania regions. Results A total of 6,883 mosquitoes were collected including: 5,628 (81.8% Anopheles arabiensis, 1,100 (15.9% Culex quinquefasciatus, 89 (1.4% Anopheles funestus, and 66 (0.9% Anopheles gambiae s.s. Of the total mosquitoes collected 3,861 were captured by CDC light trap and 3,022 by the pyrethrum spray catch method. The overall light trap: spray catch ratio was 1.3:1. Mosquito densities per room were 96.5 and 75.5 for light trap and pyrethrum spray catch respectively. Mosquito infectivity rates between villages that have high proportion of bed net owners and those without bed nets was significant (P Conclusion Malaria remains a major problem in the study areas characterized as low transmission sites. Further studies are required to establish the annual entomological inoculation rates and to observe the annual parasitaemia dynamics in these communities. Outdoor mosquitoes collection should also be considered.

  5. Insecticidal activity of Leptodactylus knudseni and Phyllomedusa vaillantii crude skin secretions against the mosquitoes Anopheles darlingi and Aedes aegypti

    Science.gov (United States)

    2014-01-01

    Background Mosquitoes are important vectors of several diseases, including malaria and dengue, and control measures are mostly performed using chemical insecticides. Unfortunately, mosquito resistance to commonly applied insecticides is widespread. Therefore, a prospection for new molecules with insecticidal activity based on Amazon biodiversity using the anurans Leptodactylus knudseni and Phyllomedusa vaillantii was performed against the mosquito species Anopheles darlingi and Aedes aegypti. Methods The granular secretion from anuran skin was obtained by manual stimulation, and lethal concentrations (LCs) for larvicidal and adulticidal tests were calculated using concentrations from 1-100 ppm. The skin secretions from the anuran species tested caused significant mortality within the first 24 hours on adults and larvae, but differed within the mosquito species. Results The skin secretions from the anuran species tested caused significant mortality within the first 24 hours on adults and larvae, but differed within the mosquito species. The calculated LC50 of L. knudseni skin secretions against An. darlingi was 0.15 and 0.2 ppm for adults and larvae, respectively, but much higher for Ae. aegypti, i.e., 19 and 38 ppm, respectively. Interestingly, the calculated LCs50 of P. vaillantii against both mosquito species in adults were similar, 1.8 and 2.1 ppm, respectively, but the LC50 for An. darlingi larvae was much lower (0.4 ppm) than for Ae aegypti (2.1 ppm). Conclusions The present experiments indicate that skin secretions from L. knudseni and P. vaillantii contain bioactive molecules with potent insecticide activity. The isolation and characterization of skin secretions components will provide new insights for potential insecticidal molecules. PMID:25165469

  6. Diversity and abundance of mosquito species in relation to their larval habitats in Mizoram, North Eastern Himalayan region.

    Science.gov (United States)

    Vanlalruia, Khawling; Senthilkumar, Nachimuthu; Gurusubramanian, Guruswami

    2014-09-01

    The abundance, richness and diversity of anopheline and culicid mosquitoes associated with their habitats, season, and physico-chemical quality of water were surveyed along six districts of Mizoram, North Eastern Himalayan region. The productivity of permanent and temporary habitat types was quantified by carrying out weekly larval sampling using a standard dipping method for a period of three years. Diversity was estimated using the Shannon index (H'), Evenness index (Heve), similarity measures cluster analysis and MANOVA. In total, 5 genera and 20 species of mosquitoes were identified: Culex quinquefasciatus, Anopheles barbirostris and Anopheles vagus were the most abundant and widely-distributed species, representing 39.71%, 29.39% and 14.52% of total mosquito individuals sampled, respectively. Anopheles sp. diversity was lowest in Lunglei district (H'=0.48) and highest in Aizawl (H'=2.03), whereas Culex sp. diversity was lowest in Lawngtlai (H'=0.38), and highest in Aizawl (H'=2.99) and Kolasib (H'=2.13). This represents the first update on the diversity and geographic distribution of the mosquitoes of Mizoram. Mosquito larvae were present in both temporary and permanent habitats suitable for breeding with monthly variations dependent on rainfall intensity, temperature, humidity and location. Early instars were more abundant significantly (Pmosquito larvae was significantly (PMosquito diversity was highest in monsoon season (July-September) and lowest in January-March. A. barbirostris, A. vagus and C. quinquefasciatus appear the most likely habitat generalist as it demonstrates both widespread distribution. Abundance and diversity of culicine and anopheline larvae were strongly associated (MANOVA) with pH, temperature, dissolved oxygen, alkalinity, phosphates and chlorides concentration of water. This information will be essential for designing and implementing mosquito larval control programs. PMID:24795213

  7. Insecticidal activity of Leptodactylus knudseni andPhyllomedusa vaillantii crude skin secretions against the mosquitoes Anopheles darlingi and Aedes aegypti

    Scientific Electronic Library Online (English)

    Frances TT, Trindade; Ângela A, Soares; Andréa A de, Moura; Tiago B, Rego; Andreimar M, Soares; Rodrigo G, Stábeli; Leonardo A, Calderon; Alexandre de, Almeida e Silva.

    2014-09-09

    Full Text Available Background Mosquitoes are important vectors of several diseases, including malaria and dengue, and control measures are mostly performed using chemical insecticides. Unfortunately, mosquito resistance to commonly applied insecticides is widespread. Therefore, a prospection for new molecules with i [...] nsecticidal activity based on Amazon biodiversity using the anurans Leptodactylus knudseni andPhyllomedusa vaillantii was performed against the mosquito species Anopheles darlingi and Aedes aegypti. Methods The granular secretion from anuran skin was obtained by manual stimulation, and lethal concentrations (LCs) for larvicidal and adulticidal tests were calculated using concentrations from 1-100 ppm. The skin secretions from the anuran species tested caused significant mortality within the first 24 hours on adults and larvae, but differed within the mosquito species. Results The skin secretions from the anuran species tested caused significant mortality within the first 24 hours on adults and larvae, but differed within the mosquito species. The calculated LC50 of L. knudseni skin secretions against An. darlingi was 0.15 and 0.2 ppm for adults and larvae, respectively, but much higher for Ae. aegypti, i.e., 19 and 38 ppm, respectively. Interestingly, the calculated LCs50 of P. vaillantii against both mosquito species in adults were similar, 1.8 and 2.1 ppm, respectively, but the LC50 for An. darlingi larvae was much lower (0.4 ppm) than for Ae aegypti (2.1 ppm). Conclusions The present experiments indicate that skin secretions from L. knudseni and P. vaillantii contain bioactive molecules with potent insecticide activity. The isolation and characterization of skin secretions components will provide new insights for potential insecticidal molecules.

  8. Determining Airborne Concentrations of Spatial Repellent Chemicals in Mosquito Behavior Assay Systems

    Science.gov (United States)

    Martin, Nicholas J.; Smith, Philip A.; Achee, Nicole L.; DeLong, Gerald T.

    2013-01-01

    Background Mosquito behavior assays have been used to evaluate the efficacy of vector control interventions to include spatial repellents (SR). Current analytical methods are not optimized to determine short duration concentrations of SR active ingredients (AI) in air spaces during entomological evaluations. The aim of this study was to expand on our previous research to further validate a novel air sampling method to detect and quantitate airborne concentrations of a SR under laboratory and field conditions. Methodology/Principal Findings A thermal desorption (TD) gas chromatography-mass spectrometry (GC-MS) method was used to determine the amount of dichlorodiphenyltrichloroethane (DDT) in samples of air. During laboratory experiments, 1 L volumes of air were collected over 10 min intervals from a three-chamber mosquito behavior assay system. Significantly higher levels of airborne DDT were measured in the chamber containing textiles treated with DDT compared to chambers free of AI. In the field, 57 samples of air were collected from experimental huts with and without DDT for onsite analysis. Airborne DDT was detected in samples collected from treated huts. The mean DDT air concentrations in these two huts over a period of four days with variable ambient temperature were 0.74 µg/m3 (n?=?17; SD?=?0.45) and 1.42 µg/m3 (n?=?30; SD?=?0.96). Conclusions/Significance The results from laboratory experiments confirmed that significantly different DDT exposure conditions existed in the three-chamber system establishing a chemical gradient to evaluate mosquito deterrency. The TD GC-MS method addresses a need to measure short-term (<1 h) SR concentrations in small volume (<100 L) samples of air and should be considered for standard evaluation of airborne AI levels in mosquito behavior assay systems. Future studies include the use of TD GC-MS to measure other semi-volatile vector control compounds. PMID:24015195

  9. Larvicidal, ovicidal, and oviposition-deterrent activities of four plant extracts against three mosquito species.

    Science.gov (United States)

    Prathibha, K P; Raghavendra, B S; Vijayan, V A

    2014-05-01

    In mosquito control programs, insecticides of botanical origin have the potential to eliminate eggs, larvae, and adults. So, the larvicidal, ovicidal, and oviposition-deterrent activities of petroleum ether and ethyl acetate extracts of the leaves of Eugenia jambolana, Solidago canadensis, Euodia ridleyi, and Spilanthes mauritiana were assayed against the three vector mosquito species, namely Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The larval bioassay was conducted following the World Health Organization method. The maximum larval mortality was found with ethyl acetate extract of S. mauritiana against the larvae of A. stephensi, A. aegypti, and C. quinquefasciatus with LC50 values of 11.51, 28.1, 14.10 ppm, respectively. The mean percent hatchability of the ovicidal activity was observed at 48-h post-treatment. The percent hatchability was found to be inversely proportional to the concentration of the extract and directly proportional to the number of eggs. The flower head extract of S. mauritiana gave 100% mortality followed by E. ridleyi, S. canadensis, and E. jambolana against the eggs of the three mosquito vectors. For oviposition-deterrent effect, out of the five concentrations tested (20, 40, 60, 80, and 100 ppm), the concentration of 100 ppm showed a significant egg laying-deterrent capacity. The oviposition activity index value of E. jambolana, E. ridleyi, S. canadensis, and S. mauritiana against A. aegypti, A. stephensi, C. quinquefasciatus at 100 ppm were -0.71, -0.71, -0.90, -0.93, -0.85, -0.91, -1, -1, -0.71, -0.85, -1, and -1, respectively. These results suggest that the leaf/flower extracts of certain local plants have the potential to be developed as possible eco-friendly means for the control of mosquitoes. PMID:24562451

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

    Science.gov (United States)

    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

  11. The entomopathogenic fungus Beauveria bassiana reduces instantaneous blood feeding in wild multi-insecticide-resistant Culex quinquefasciatus mosquitoes in Benin, West Africa

    Directory of Open Access Journals (Sweden)

    Howard Annabel FV

    2010-09-01

    Full Text Available Abstract Background Mosquito-borne diseases are still a major health risk in many developing countries, and the emergence of multi-insecticide-resistant mosquitoes is threatening the future of vector control. Therefore, new tools that can manage resistant mosquitoes are required. Laboratory studies show that entomopathogenic fungi can kill insecticide-resistant malaria vectors but this needs to be verified in the field. Methods The present study investigated whether these fungi will be effective at infecting, killing and/or modifying the behaviour of wild multi-insecticide-resistant West African mosquitoes. The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were separately applied to white polyester window netting and used in combination with either a permethrin-treated or untreated bednet in an experimental hut trial. Untreated nets were used because we wanted to test the effect of fungus alone and in combination with an insecticide to examine any potential additive or synergistic effects. Results In total, 1125 female mosquitoes were collected during the hut trial, mainly Culex quinquefasciatus Say. Unfortunately, not enough wild Anopheles gambiae Giles were collected to allow the effect the fungi may have on this malaria vector to be analysed. None of the treatment combinations caused significantly increased mortality of Cx. quinquefasciatus when compared to the control hut. The only significant behaviour modification found was a reduction in blood feeding by Cx. quinquefasciatus, caused by the permethrin and B. bassiana treatments, although no additive effect was seen in the B. bassiana and permethrin combination treatment. Beauveria bassiana did not repel blood foraging mosquitoes either in the laboratory or field. Conclusions This is the first time that an entomopathogenic fungus has been shown to reduce blood feeding of wild mosquitoes. This behaviour modification indicates that B. bassiana could potentially be a new mosquito control tool effective at reducing disease transmission, although further field work in areas with filariasis transmission should be carried out to verify this. In addition, work targeting malaria vector mosquitoes should be carried out to see if these mosquitoes manifest the same behaviour modification after infection with B. bassiana conidia.

  12. Patent literature on mosquito repellent inventions which contain plant essential oils--a review.

    Science.gov (United States)

    Pohlit, Adrian Martin; Lopes, Norberto Peporine; Gama, Renata Antonaci; Tadei, Wanderli Pedro; Neto, Valter Ferreira de Andrade

    2011-04-01

    Bites Bites of mosquitoes belonging to the genera Anopheles Meigen, Aedes Meigen, Culex L. and Haemagogus L. are a general nuisance and are responsible for the transmission of important tropical diseases such as malaria, hemorrhagic dengue and yellow fevers and filariasis (elephantiasis). Plants are traditional sources of mosquito repelling essential oils (EOs), glyceridic oils and repellent and synergistic chemicals. A Chemical Abstracts search on mosquito repellent inventions containing plant-derived EOs revealed 144 active patents mostly from Asia. Chinese, Japanese and Korean language patents and those of India (in English) accounted for roughly 3/4 of all patents. Since 1998 patents on EO-containing mosquito repellent inventions have almost doubled about every 4 years. In general, these patents describe repellent compositions for use in topical agents, cosmetic products, incense, fumigants, indoor and outdoor sprays, fibers, textiles among other applications. 67 EOs and 9 glyceridic oils were individually cited in at least 2 patents. Over 1/2 of all patents named just one EO. Citronella [Cymbopogon nardus (L.) Rendle, C.winterianus Jowitt ex Bor] and eucalyptus (Eucalyptus L?Hér. spp.) EOs were each cited in approximately 1/3 of all patents. Camphor [Cinnamomum camphora (L.) J. Presl], cinnamon (Cinnamomum zeylanicum Blume), clove [Syzygium aromaticum (L.) Merr. & L.M. Perry], geranium (Pelargonium graveolens L?Hér.), lavender (Lavandula angustifolia Mill.), lemon [Citrus × limon (L.) Osbeck], lemongrass [Cymbopogon citratus (DC.) Stapf] and peppermint (Mentha × piperita L.) EOs were each cited in > 10% of patents. Repellent chemicals present in EO compositions or added as pure “natural” ingredients such as geraniol, limonene, p-menthane-3,8-diol, nepetalactone and vanillin were described in approximately 40% of all patents. About 25% of EO-containing inventions included or were made to be used with synthetic insect control agents having mosquito repellent properties such as pyrethroids, N,N-diethyl-m-toluamide (DEET), (±)-p-menthane-3,8-diol (PMD) and dialkyl phthalates. Synergistic effects involving one or more EOs and synthetic and/or natural components were claimed in about 10% of all patents. Scientific literature sources provide evidence for the mosquito repellency of many of the EOs and individual chemical components found in EOs used in patented repellent inventions. PMID:21328177

  13. Human skin emanations in the host-seeking behaviour of the malaria mosquito Anopheles gambiae

    OpenAIRE

    Braks, M.A.H.

    1999-01-01

    Malaria is an infectious disease caused by a parasite ( Plasmodium spp.) that is transmitted between human individuals by mosquitoes, belonging to the order of insects, Diptera, family of Culicidae (mosquitoes) and genus of Anopheles (malaria mosquitoes). Mosquitoes feed on humans (and other animals) because they need blood for their reproduction. Like most other haematophagous insects, only the female mosquitoes bite and use the protein-rich blood meal for egg development. Whilst feeding on ...

  14. Dispersal of Culex Mosquitoes (Diptera: Culicidae) From a Wastewater Treatment Facility

    OpenAIRE

    Ciota, Alexander T.; Drummond, Cori L.; Ruby, Meghan A.; Drobnack, Jason; EBEL, GREGORY D.; KRAMER, LAURA D.

    2012-01-01

    A mark-recapture project examined dispersal and flight distances of Culex mosquitoes from a wastewater treatment plant in Albany, NY, during 2007 and 2008. A self-marking device was constructed to mark egressing mosquitoes with fluorescent marking powder. Mosquitoes were recaptured using 30 CDC miniature light traps located within a 2.0 km radius of the marking site. A total of 13 and 10 marked Culex mosquitoes were recaptured in 2007 and 2008, respectively. Culex mosquitoes traveled a minimu...

  15. Repellent, Irritant and Toxic Effects of 20 Plant Extracts on Adults of the Malaria Vector Anopheles gambiae Mosquito

    Science.gov (United States)

    Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

    2013-01-01

    Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged. PMID:24376515

  16. Aedes Mosquito Saliva Modulates Rift Valley Fever Virus Pathogenicity

    Science.gov (United States)

    Le Coupanec, Alain; Babin, Divya; Fiette, Laurence; Jouvion, Grégory; Ave, Patrick; Misse, Dorothee; Bouloy, Michèle; Choumet, Valerie

    2013-01-01

    Background Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. Mosquito saliva contains compounds that counteract the hemostatic, inflammatory, and immune responses of the host. Modulation of these defensive responses may facilitate virus infection. Indeed, Aedes mosquito saliva played a crucial role in the vector's capacity to effectively transfer arboviruses such as the Cache Valley and West Nile viruses. The role of mosquito saliva in the transmission of Rift Valley fever virus (RVFV) has not been investigated. Objective Using a murine model, we explored the potential for mosquitoes to impact the course of RVF disease by determining whether differences in pathogenesis occurred in the presence or absence of mosquito saliva and salivary gland extract. Methods C57BL/6NRJ male mice were infected with the ZH548 strain of RVFV via intraperitoneal or intradermal route, or via bites from RVFV-exposed mosquitoes. The virus titers in mosquitoes and mouse organs were determined by plaque assays. Findings After intraperitoneal injection, RVFV infection primarily resulted in liver damage. In contrast, RVFV infection via intradermal injection caused both liver and neurological symptoms and this route best mimicked the natural infection by mosquitoes. Co-injections of RVFV with salivary gland extract or saliva via intradermal route increased the mortality rates of mice, as well as the virus titers measured in several organs and in the blood. Furthermore, the blood cell counts of infected mice were altered compared to those of uninfected mice. Interpretation Different routes of infection determine the pattern in which the virus spreads and the organs it targets. Aedes saliva significantly increases the pathogenicity of RVFV. PMID:23785528

  17. How blood-derived odor influences mate-choice decisions by a mosquito-eating predator

    OpenAIRE

    Cross, Fiona R.; JACKSON, ROBERT R.; Pollard, Simon D.

    2009-01-01

    Evarcha culicivora (Araneae, Salticidae) feeds indirectly on vertebrate blood by choosing, as preferred prey, bloodcarrying female mosquitoes. Mutual mate-choice behavior is also pronounced in this species. Here we show that, when E. culicivora feeds indirectly on blood, it acquires a diet-related odor that makes it more attractive to the opposite sex. The mate-choice decisions of the adults of both sexes were investigated in a series of experiments based on comparing how long the test spider...

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

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    Paolucci Pimenta Paulo

    2011-01-01

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

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

    Science.gov (United States)

    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

  20. Evaluation of organophosphorus and synthetic pyrethroid insecticides against six vector mosquitoe species

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    Montada Dorta Domingo

    1993-01-01

    Full Text Available Three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquitoe species: Culex quinquefasciatus (Filariasis and Aedes albopictus (Dengue (both laboratory and field strains; laboratory strains of Aedes aegypti (Dengue, Anopheles slephensi and Anopheles culicifacies (Malaria, and Culex tritaeniorhynchus (Japanese encephalitis in India. From the LC50 values obtained for these insecticides, it was found that all mosquito species including the field strains of Cx. quinquefasciatus and Ae. albopictus were highly susceptible Except for Cx. quinquefasciatus (field strain against malathion, 100% mortality was observed at the discriminating dosages recommended by World Health Organization. The residual effect of alphamethrin, deltamethrin, malathion and folithion at 25 mg (ai/m² on different surfaces against six species of vector mosquitoes showed that alphamethrin was the most effective on all four treated surfaces (mud, plywood, cement and thatch. Nevertheless, residual efficacy lasted longer on thatch than on the other surfaces. Therefore, synthetic pyrethroids such as alphamethrin can be effectively employed in integrated vector control operations.

  1. Increase in larval gut proteolytic activities and Bti resistance in the Dengue fever mosquito.

    Science.gov (United States)

    Tetreau, Guillaume; Stalinski, Renaud; David, Jean-Philippe; Després, Laurence

    2013-02-01

    The bioinsecticide Bacillus thuringiensis var. israelensis (Bti) is increasingly used worldwide for mosquito control. Although no established resistance to Bti has been described in the field so far, a resistant Aedes aegypti strain (LiTOX strain) was selected in the laboratory using field-collected leaf litter containing Bti toxins. This selected strain exhibits a moderate resistance level to Bti, but a high resistance level to individual Cry toxins. As Bti contains four different toxins, generalist resistance mechanisms affecting mosquito tolerance to different toxins were expected in the resistant strain. In the present work, we show that the resistant strain exhibits an increase of various gut proteolytic activities including trypsins, leucine-aminopeptidases, and carboxypeptidase A activities. These elevated proteolytic activities resulted in a faster activation of Cry4Aa protoxins while Cry4Ba or Cry11Aa were not affected. These results suggest that changes in proteolytic activities may contribute to Bti resistance in mosquitoes together with other mechanisms. PMID:23192850

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

    Science.gov (United States)

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

    2014-12-01

    Worldwide evolution of mosquito resistance to chemical insecticides represents a major challenge for public health, and the future of vector control largely relies on the development of biological insecticides that can be used in combination with chemicals (integrated management), with the expectation that populations already resistant to chemicals will not become readily resistant to biological insecticides. However, little is known about the metabolic pathways affected by selection with chemical or biological insecticides. Here we show that Aedes aegypti, a laboratory mosquito strain selected with a biological insecticide (Bacillus thuringiensis israelensis, Bti) evolved increased transcription of many genes coding for endopeptidases while most genes coding for detoxification enzymes were under-expressed. By contrast, in strains selected with chemicals, genes encoding detoxification enzymes were mostly over-expressed. In all the resistant strains, genes involved in immune response were under-transcribed, suggesting that basal immunity might be a general adjustment variable to compensate metabolic costs caused by insecticide selection. Bioassays generally showed no evidence for an increased susceptibility of selected strains towards the other insecticide type, and all chemical-resistant strains were as susceptible to Bti as the unselected parent strain, which is a good premise for sustainable integrated management of mosquito populations resistant to chemicals. PMID:25540155

  3. Wolbachia Infection and Mitochondrial DNA Comparisons among Culex Mosquitoes in South West Iran

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    A. Behbahani

    2012-01-01

    Full Text Available The control of mosquito borne diseases needs new methods given widespread insecticide resistance in many mosquito species. The inherited endosymbiont Wolbachia, found in many arthropods, provides a biological system to reduce the transmission of these diseases and replace the population of vectors with non-vectors using cytoplasmic incompatibility. The aim of this study was to understand the rate of Wolbachia infection among Culex species in the region and to see the effect of Wolbachia infection on mitochondrial genome. In this study three species of Culex mosquitoes were collected from Shoushtar in south west of Iran and examined for Wolbachia infection by Polymerase Chain Reaction (PCR. All of the C. quinquefasciatus specimens were infected with Wolbachia, while C. tritaeniorynchus and C. theileri showed no infection with Wolbachia. The 340 bp of AT rich of mtDNA was sequenced from 30 individuals, 10 individuals of each species. Three sequence haplotypes were found in C. tritaeniorynchus and C. theileri while there was only one haplotype in C. quinquefasciatus. The reduction of haplotypes diversity may be result of a sweep of Wolbachia in this species.

  4. TRANSMISSION MODEL OF CHIKUNGUNYA FEVER IN THE PRESENCE OF TWO SPECIES OF AEDES MOSQUITOES

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    Surapol Naowarat

    2013-01-01

    Full Text Available In 2008 there was a large outbreak of Chikungunya fever in the south of Thailand. Chikungunya fever is a febrile disease transmitted to humans by the bite of infected Aedes mosquitoes. The symptoms of this disease are a sudden onset of a fever, chills, headache, nausea, vomiting, joint pain with or without swelling, low back pain and rash. In this study we study the effects of there being two species of Aedes mosquito (Aedes aegypti and Aedes albopictus present. In this study, we assume that both the human and mosquito populations are constant. A dynamical model of Chikungunya fever is proposed and analyzed. The Routh-Hurwitz criteria are used to determine the stability of the model. The conditions which would lead to either the disease free equilibrium state or the disease endemic equilibrium state to exist is determined. The numerical simulations are done in order to illustrate the behaviors of transmission of disease for different values of parameters. It is shown that the destruction of breeding sites could be an effective method to control this disease.

  5. Applications of a sugar-based surveillance system to track arboviruses in wild mosquito populations.

    Science.gov (United States)

    van den Hurk, Andrew F; Hall-Mendelin, Sonja; Townsend, Michael; Kurucz, Nina; Edwards, Jim; Ehlers, Gerhard; Rodwell, Chris; Moore, Frederick A; McMahon, Jamie L; Northill, Judith A; Simmons, Russell J; Cortis, Giles; Melville, Lorna; Whelan, Peter I; Ritchie, Scott A

    2014-01-01

    Effective arbovirus surveillance is essential to ensure the implementation of control strategies, such as mosquito suppression, vaccination, or dissemination of public warnings. Traditional strategies employed for arbovirus surveillance, such as detection of virus or virus-specific antibodies in sentinel animals, or detection of virus in hematophagous arthropods, have limitations as an early-warning system. A system was recently developed that involves collecting mosquitoes in CO2-baited traps, where the insects expectorate virus on sugar-baited nucleic acid preservation cards. The cards are then submitted for virus detection using molecular assays. We report the application of this system for detecting flaviviruses and alphaviruses in wild mosquito populations in northern Australia. This study was the first to employ nonpowered passive box traps (PBTs) that were designed to house cards baited with honey as the sugar source. Overall, 20/144 (13.9%) of PBTs from different weeks contained at least one virus-positive card. West Nile virus Kunjin subtype (WNVKUN), Ross River virus (RRV), and Barmah Forest virus (BFV) were detected, being identified in 13/20, 5/20, and 2/20 of positive PBTs, respectively. Importantly, sentinel chickens deployed to detect flavivirus activity did not seroconvert at two Northern Territory sites where four PBTs yielded WNVKUN. Sufficient WNVKUN and RRV RNA was expectorated onto some of the honey-soaked cards to provide a template for gene sequencing, enhancing the utility of the sugar-bait surveillance system for investigating the ecology, emergence, and movement of arboviruses. PMID:24359415

  6. Expresión de toxinas activas para larvas de mosquito por una cepa nativa de Asticaccaulis excentricus

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    Sergio Ordúz

    2000-02-01

    Full Text Available

    El control de mosquitos con insecticidas biológicos, como las toxinas producidas por especies del género Bacillus ha sido usado ampliamente en muchos países. Sin embargo, la rápida sedimentación de éstas las coloca fuera del alcance de la zona de alimentación de las larvas de mosquito. Con el propósito de resolver este problema se ha propuesto clonar los genes de dichas toxinas en bacterias acuáticas que son capaces de vivir y multiplicarse en la parte superior de la columna de agua, donde se alimentas los mosquitos anofelinos. Se escogieron dos cepas de la bacteria acuática Asticaccaulis excentricus para expresar los genes de la toxina binaria de B. sphaericus y el gen cry11Bb de B. thuringiensis subesp. Medellín clonados en un vector de expresión adecuado. En experimentos de alimentación se encontró que larvas de las especies Culex quinquefasciatus, Aedes aegypti y Anopheles albimanus fueron capaces de sobrevivir en una dieta basada exclusivamente en esta bacteria gram negativa. Las células de A. excentricus recombinante fueron capaces de expresar ambos genes, pero solamente la cepa expresando los genes de la toxina binaria de B. sphaericus fue tóxica para larvas de mosquito. Extractos de proteasas de A. excentricus no degradaron la toxina Cry11Bb, lo que indica que es otro el mecanismo que interfiere con la expresión de la toxicidad de la toxina Cry11Bb en esta bacteria recombinante. Los experimentos de flotación mostraron que A. excentricus recombiante se mantiene en la parte superior de la columna de agua al igual que las cepas nativas, y por más tiempo que las cepas de Bacillus.

  7. Mosquito larvicidal constituents from Lantana viburnoides sp viburnoides var kisi (A. rich Verdc (Verbenaceae

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    Mayunga H.H. Nkunya

    2008-08-01

    Full Text Available Background & objectives: Lantana viburnoides sp viburnoides var kisi is used in Tanzania ethnobotanically to repel mosquitoes as well as in traditional medicine for stomach ache relief. Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks were carried out in order to identify the bioactive components for controlling Anopheles gambiae s.s. mosquito larvae. Methods: Twenty late III or early IV instar larvae of An. gambiae s.s. were exposed to various concentrations of the plant extracts, fractions, blends and pure compounds, and were assayed in the laboratory by using the protocol of WHO 1996. Mean mortalities were compared using Dunnett’s test (p<0.05 and lethal concentration calculated by Lackfit Inversel of the SAS programme. Results: The crude extract (LC50 = 7.70 ppm in 72 h and fractions exhibited different level of mosquito larvicidal activity with subtraction of some fractions resulting in activity enhancement. The active fractions contained furanonaphthaquinones regio-isomers (LC50 = 5.48–5.70 ppm in 72 h and the lantadene triterpenoid camaric acid (LC50 = 6.19 ppm in 72 h as active principles while the lupane triterpenoid betulinic acid (LC50 < 10 ppm in 72 h was obtained from the least active fraction. Interpretation & conclusion: Crude extracts and some fractions had higher or comparable larvicidal activity to the pure compounds. These results demonstrate that L. viburnoides sp viburnoides var kisi extracts may serve as larvicides for managing various mosquito habitats even in their semi-purified form. The isolated compounds can be used as distinct markers in the active extracts or plant materials belonging to the genus Lantana.

  8. Efficacy of Thai herbal essential oils as green repellent against mosquito vectors.

    Science.gov (United States)

    Soonwera, Mayura; Phasomkusolsil, Siriporn

    2015-02-01

    Repellency activity of Thai essential oils derived from ylang ylang (Cananga odorata (Lamk.) Hook.f. & Thomson: Annonaceae) and lemongrass (Cymbopogon citratus (DC.) Stapf: Poaceae) were tested against two mosquito vectors, Aedes aegypti (L.) and Culex quinquefasciatus (Say). There were compared with two chemical repellents (DEET 20% w/w; Sketolene Shield(®) and IR3535, ethyl butylacetylaminopropionate 12.5% w/w; Johnson's Baby Clear Lotion Anti-Mosquito(®)). Each herbal repellent was applied in three diluents; coconut oil, soybean oil and olive oil at 0.33 ?l/cm(2) on the forearm of volunteers. All herbal repellent exhibited higher repellent activity than IR3535 12.5% w/w, but lower repellent activity than DEET 20% w/w. The C. odorata oil in coconut oil exhibited excellent activity with 98.9% protection from bites of A. aegypti for 88.7±10.4 min. In addition, C. citratus in olive oil showed excellent activity with 98.8% protection from bites of C. quinquefasciatus for 170.0±9.0 min. While, DEET 20% w/w gave protection for 155.0±7.1-182.0±12.2 min and 98.5% protection from bites of two mosquito species. However, all herbal repellent provided lower repellency activity (97.4-98.9% protection for 10.5-88.7 min) against A. aegypti than C. quinquefasciatus (98.3-99.2% protection for 60-170 min). Our data exhibited that C. odorata oil and C. citratus oil are suitable to be used as green repellents for mosquito control, which are safe for humans, domestic animals and environmental friendly. PMID:25438256

  9. Integrated mosquito larval source management reduces larval numbers in two highland villages in western Kenya

    Directory of Open Access Journals (Sweden)

    Imbahale Susan S

    2012-05-01

    Full Text Available Abstract Background In western Kenya, malaria remains one of the major health problems and its control remains an important public health measure. Malaria control is by either use of drugs to treat patients infected with malaria parasites or by controlling the vectors. Vector control may target the free living adult or aquatic (larval stages of mosquito. The most commonly applied control strategies target indoor resting mosquitoes. However, because mosquitoes spend a considerable time in water, targeting the aquatic stages can complement well with existing adult control measures. Methods Larval source management (LSM of malaria vectors was examined in two villages i.e. Fort Ternan and Lunyerere, with the aim of testing strategies that can easily be accessed by the affected communities. Intervention strategies applied include environmental management through source reduction (drainage of canals, land levelling or by filling ditches with soil, habitat manipulation (by provision of shading from arrow root plant, application of Bacillus thuringiensis var israelensis (Bti and the use of predatory fish, Gambusia affinis. The abundance of immature stages of Anopheles and Culex within intervention habitats was compared to that within non-intervention habitats. Results The findings show that in Fort Ternan no significant differences were observed in the abundance of Anopheles early and late instars between intervention and non-intervention habitats. In Lunyerere, the abundance of Anopheles early instars was fifty five times more likely to be present within non-intervention habitats than in habitats under drainage. No differences in early instars abundance were observed between non-intervention and habitats applied with Bti. However, late instars had 89?% and 91?% chance of being sampled from non-intervention rather than habitats under drainage and those applied with Bti respectively. Conclusion Most of these interventions were applied in habitats that arose due to human activities. Involvement of community members in control programs would be beneficial in the long term once they understand the role they play in malaria transmission. Apart from the need for communities to be educated on their role in malaria transmission, there is a need to develop and test strategies that can easily be accessed and hence be used by the affected communities. The proposed LSM strategies target outdoor immature mosquitoes and hence can complement well with control measures that target indoor resting vectors. Therefore inclusion of LSM in Integrated Vector Management (IVM program would be beneficial.

  10. ROLE OF DRAGONFLY (Brachytron pratense NYMPH AS A BIOCONTROL AGENT OF LARVAL MOSQUITOES

    Directory of Open Access Journals (Sweden)

    G. Chandra

    2012-10-01

    Full Text Available The failure of traditional vector control operations through chemical insecticides renewed interest in biological control method. In the present study Dragonfly (Brachytron pratense nymph has been proved to be a strong biocontrol agent of Anopheles suhpictus larvae in the laboratory condition. Average daily larval feeding rate of B. pratense nymph decreased when the search area was increased. Feeding rate increased when prey density was increased. In the field conditions also, B. pratense played very effective role as predator of different species of larval mosquitoes.

  11. Aparelho de sucção tipo aspirador para captura de mosquitos A "vacuum-cleaner" type of suction apparatus for the collection of mosquitoes

    Directory of Open Access Journals (Sweden)

    Délsio Natal

    1984-10-01

    Full Text Available É feita a descrição de aparelho portátil de sucção tipo aspirador, para captura de mosquitos Culicidae. São sugeridas adaptações para coletas em diferentes situações. São feitos comentários sobre sua aplicação em pesquisa de mosquitos.A portable suction apparatus, which functions like a vacuum cleaner used for the collection of Culicidae mosquitoes is described. Adaptations for collecting in differents situations are suggested and some comments about its application in mosquitoes surveys are made.

  12. Mosquitoes actively remove drops deposited by fog and dew.

    Science.gov (United States)

    Dickerson, Andrew K; Hu, David L

    2014-12-01

    We report mosquito behaviors for removing accumulated drops of water which would otherwise increase the energy expended during takeoff and free flight. These techniques take advantage of the insect's small size and great structural strength. To dry their wings before takeoff, mosquitoes employ a flutter stroke, at double the wingbeat frequency of normal flight, generating nearly 2500 gravities of acceleration. Mosquitoes may also remove drops by the respective accelerations associated with takeoff and collision with the ground. We correlate the accelerations and size of drops ejected using a simple model involving the drop's inertial force and surface tension. We note mosquitoes may use similar techniques to remove synthetic drops, making our observations applicable for understanding the resistance of insects to insecticides. PMID:24876192

  13. Comparative repellency of 38 essential oils against mosquito bites.

    Science.gov (United States)

    Trongtokit, Yuwadee; Rongsriyam, Yupha; Komalamisra, Narumon; Apiwathnasorn, Chamnarn

    2005-04-01

    The mosquito repellent activity of 38 essential oils from plants at three concentrations was screened against the mosquito Aedes aegypti under laboratory conditions using human subjects. On a volunteer's forearm, 0.1 mL of oil was applied per 30 cm2 of exposed skin. When the tested oils were applied at a 10% or 50% concentration, none of them prevented mosquito bites for as long as 2 h, but the undiluted oils of Cymbopogon nardus (citronella), Pogostemon cablin (patchuli), Syzygium aromaticum (clove) and Zanthoxylum limonella (Thai name: makaen) were the most effective and provided 2 h of complete repellency. From these initial results, three concentrations (10%, 50% and undiluted) of citronella, patchouli, clove and makaen were selected for repellency tests against Culex quinquefasciatus and Anopheles dirus. As expected, the undiluted oil showed the highest protection in each case. Clove oil gave the longest duration of 100% repellency (2-4 h) against all three species of mosquito. PMID:16041723

  14. Dirofilaria repens microfilariae in Aedes vexans mosquitoes in Slovakia.

    Czech Academy of Sciences Publication Activity Database

    Bocková, E.; Rudolf, Ivo; Ko?išová, A.; Betášová, Lenka; Venclíková, Kristýna; Mendel, Jan; Hubálek, Zden?k

    2013-01-01

    Ro?. 112, ?. 10 (2013), s. 3465-3470. ISSN 0932-0113 Institutional support: RVO:68081766 Keywords : Dirofilaria * mosquitoes * Aedes vexans Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.327, year: 2013

  15. Gradual diffusive capture: slow death by many mosquito bites

    International Nuclear Information System (INIS)

    We study the dynamics of a single diffusing particle (a ‘man’) with diffusivity DM that is attacked by another diffusing particle (a ‘mosquito’) with fixed diffusivity Dm. Each time the mosquito meets and bites the man, the diffusivity of the man is reduced by a fixed amount, while the diffusivity of the mosquito is unchanged. The mosquito is also displaced by a small distance ±a with respect to the man after each encounter. The man is defined as dead when DM reaches zero. At the moment when the man dies, his probability distribution of displacements x is given by a Cauchy form, which asymptotically decays as x?2, while the distribution of times t when the man dies decays asymptotically as t?3/2, which has the same form as the one-dimensional first-passage probability. (paper)

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

    OpenAIRE

    Jasinskiene, Nijole; Juhn, Jennifer; JAMES, ANTHONY A.

    2007-01-01

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

  17. Vector competence of New Zealand mosquitoes for selected arboviruses.

    Science.gov (United States)

    Kramer, Laura D; Chin, Pam; Cane, Rachel P; Kauffman, Elizabeth B; Mackereth, Graham

    2011-07-01

    New Zealand (NZ) historically has been free of arboviral activity with the exception of Whataroa virus (Togaviridae: Alphavirus), which is established in bird populations and is transmitted by local mosquitoes. This naive situation is threatened by global warming, invasive mosquitoes, and tourism. To determine the threat of selected medically important arboviruses to NZ, vector competence assays were conducted using field collected endemic and introduced mosquito species. Four alphaviruses (Togaviridae): Barmah Forest virus, Chikungunya virus, Ross River virus, and Sindbis virus, and five flaviviruses (Flaviviridae): Dengue virus 2, Japanese encephalitis virus, Murray Valley encephalitis virus, West Nile virus, and Yellow fever virus were evaluated. Results indicate some NZ mosquito species are highly competent vectors of selected arboviruses, particularly alphaviruses, and may pose a threat were one of these arboviruses introduced at a time when the vector was prevalent and the climatic conditions favorable for virus transmission. PMID:21734146

  18. Ethnobotanical study of some of mosquito repellent plants in north-eastern Tanzania

    Directory of Open Access Journals (Sweden)

    Tenu Filemoni

    2008-08-01

    Full Text Available Abstract Background The use of plant repellents against nuisance biting insects is common and its potential for malaria vector control requires evaluation in areas with different level of malaria endemicity. The essential oils of Ocimum suave and Ocimum kilimandscharicum were evaluated against malaria vectors in north-eastern Tanzania. Methodology An ethnobotanical study was conducted at Moshi in Kilimanjaro region north-eastern Tanzania, through interviews, to investigate the range of species of plants used as insect repellents. Also, bioassays were used to evaluate the protective potential of selected plants extracts against mosquitoes. Results The plant species mostly used as repellent at night are: fresh or smoke of the leaves of O. suave and O. kilimandscharicum (Lamiaceae, Azadirachta indica (Meliaceae, Eucalyptus globules (Myrtaceae and Lantana camara (Verbenaceae. The most popular repellents were O. kilimandscharicum (OK and O. suave (OS used by 67% out of 120 households interviewed. Bioassay of essential oils of the two Ocimum plants was compared with citronella and DEET to study the repellence and feeding inhibition of untreated and treated arms of volunteers. Using filter papers impregnated with Ocimum extracts, knockdown effects and mortality was investigated on malaria mosquito Anopheles arabiensis and Anopheles gambiae, including a nuisance mosquito, Culex quinquefasciatus. High biting protection (83% to 91% and feeding inhibition (71.2% to 92.5% was observed against three species of mosquitoes. Likewise the extracts of Ocimum plants induced KD90 of longer time in mosquitoes than citronella, a standard botanical repellent. Mortality induced by standard dosage of 30 mg/m2 on filter papers, scored after 24 hours was 47.3% for OK and 57% for OS, compared with 67.7% for citronella. Conclusion The use of whole plants and their products as insect repellents is common among village communities of north-eastern Tanzania and the results indicate that the use of O. suave and O. kilimandscharicum as a repellent would be beneficial in reducing vector biting. The widespread use of this approach has a potential to complement other control measures.

  19. Transcriptome Analysis of Aedes aegypti Transgenic Mosquitoes with Altered Immunity

    OpenAIRE

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

    2011-01-01

    The mosquito immune system is involved in pathogen-elicited defense responses. The NF-?B factors REL1 and REL2 are downstream transcription activators of Toll and IMD immune pathways, respectively. We have used genome-wide microarray analyses to characterize fat-body-specific gene transcript repertoires activated by either REL1 or REL2 in two transgenic strains of the mosquito Aedes aegypti. Vitellogenin gene promoter was used in each transgenic strain to ectopically express either REL1 (REL...

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

    OpenAIRE

    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 cu...

  1. Statics and dynamics of malaria infection in Anopheles mosquitoes

    OpenAIRE

    Ellis McKenzie F; Smith David L

    2004-01-01

    Abstract The classic formulae in malaria epidemiology are reviewed that relate entomological parameters to malaria transmission, including mosquito survivorship and age-at-infection, the stability index (S), the human blood index (HBI), proportion of infected mosquitoes, the sporozoite rate, the entomological inoculation rate (EIR), vectorial capacity (C) and the basic reproductive number (R0). The synthesis emphasizes the relationships among classic formulae and reformulates a simple dynamic...

  2. Malaria Situation and Anopheline Mosquitoes in Qom Province, Central Iran

    OpenAIRE

    MR Abai; Saghafipour, A; B Farzinnia

    2010-01-01

    "nAbstract "nBackground: The aims of this study was to analysis the current situation of malaria and to find the distribution of anopheline mosquitoes, as probable vectors of the disease, in Qom Province, central Iran. "nMethods: This study was carried out in two parts. First stage was data collection about malaria cases using recorded documents of patients in the Province health center, during 2001–2008. The second stage was entomological survey conducted by mosquito...

  3. Nature or nurture in mosquito resistance to malaria?

    OpenAIRE

    Hurd, Hilary

    2007-01-01

    The genetic basis of mosquito resistance to malaria parasites is well established and currently receives a lot of attention. However this is not the sole determinant of the success or failure of an infection. In a recent article, Lambrechts and colleagues report the influence of the quality of the external environment of a mosquito on infection. They indicate that external variations could substantially reduce the importance of resistance genes in determining infection by malaria parasites. F...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  6. Biting activity of mosquito species (Diptera: Culicidae) in the Turkey-Armenia border area, Ararat Valley, Turkey.

    Science.gov (United States)

    Aldemir, Adnan; Bedir, Hilal; Demirci, Berna; Alten, Bulent

    2010-01-01

    During nine consecutive nights in July 2007 (from 18:15-05:45 h), mosquitoes landing-biting on humans were collected outdoors and indoors at the Turkey-Armenia border. A total of 1005 females were collected consisting of nine species. The dominant species was Aedes dorsalis (Meigen) (47.5% of total catch), followed by Anopheles hyrcanus (Pallas) (22.9%), Culex theileri (Theobald) (9.3%),Ae. vexans (Meigen) (6.6%), Ae. caspius (Pallas) (4.9%),Anopheles maculipennis s.l. (Meigen) (3.1%), Culex territans (Walker) (2.8%), Coquillettidia richiardii (Ficalbi) (1.6%), and Cx. pipiens L. (1.5%). The biting rate outdoors (15.1 mosquitoes/human/h) was greater than indoors (3.4 mosquitoes/human/h). The landing-biting of Ae. dorsalis peaked at dusk (19:15-19:45 h) and dawn (04:15-04:45 h). Ae. vexans activity increased soon after dark (20:15-20:45 h) and reached a peak at dawn (04:15-04:45 h). Maximum biting activity of An. hyrcanus and Cx. theileri occurred during the first sampling interval after dusk (20:15-20:45 h). A large number of An. maculipennis s.l. adults were collected during the second half of the night. We believe that these findings will contribute to decisions on the timing of mosquito control in Ararat Valley. PMID:20180304

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

    Science.gov (United States)

    Fawaz, Emadeldin Y; Allan, Sandra A; Bernier, Ulrich R; Obenauer, Peter J; Diclaro, Joseph W

    2014-12-01

    Mosquitoes of various species mate in swarms comprised of tens of thousands of flying males. In this study, we examined Aedes aegypti swarming behavior and identified associated chemical cues. Novel evidence is provided that Ae. aegypti females aggregate by means of olfactory cues, such as aggregation pheromones. Isolation of Ae. aegypti aggregation pheromones was achieved by aeration of confined mosquitoes and collection of associated volatiles by glass filters. The collected volatiles were identified through gas chromatography mass spectrometry (GCMS). Three aggregation pheromones were collected and identified as 2,6,6-trimethylcyclohex-2-ene-1,4-dione (ketoisophorone) (CAS# 1125-21-9, t(R) = 18.75), 2,2,6-trimethylcyclohexane-1,4-dione (the saturated analog of ketoisophorone) (CAS# 20547-99-3, t(R) = 20.05), and 1-(4-ethylphenyl) ethanone (CAS# 937-30-4, t(R) = 24.22). Our biological studies revealed that the identified compounds stimulated mosquito behavior under laboratory conditions. The mechanism of mosquito swarm formation is discussed in light of our behavioral study findings. A preliminary field trial demonstrated the potential application of the isolated aggregation pheromones in controlling Ae. aegypti. PMID:25424264

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

    Science.gov (United States)

    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

  9. Species Composition and Relative Abundance of Mosquitoes in Swat, Pakistan

    Directory of Open Access Journals (Sweden)

    Ikram Ilahi

    2013-04-01

    Full Text Available A comprehensive survey of mosquitoes (Diptera: Culicidae was conducted in Swat Pakistan, from April to September during 2000. The survey involved the sampling of both, adult and immature stages of mosquitoes, and recovered a total of 21 species in five genera. Sampling of adult mosquitoes involved Pyrethrum spray collections, Man-biting collections, and Animal-biting collection. Immature stages of mosquitoes were collected from variety of habitats including springs, irrigation channels, rice fields, marshes, temporary pools, construction pools, agriculture pools, river margins, ditches, waste water drains, wells and tree holes. During the study most of the species built up their populations in June, July and August, while a few increased their populations in September. During the survey of immature stages, from a total of 138 samples taken, Cx. quinquefasciatus showed maximum frequency of occurrence (recovered from 48 samples followed by An. maculatus (17 samples, Cx. pseudovishnui (14 samples, An. annularis and An. stephensi (13 samples each, Cx. bitaeniorhynchus (11 samples, An. splendidus (5 samples and Cx. theileri (4 samples. The rest of the species occurred infrequently. The observations on habitat specificity of different species of mosquitoes showed the rice fields as the most favorable site for mosquito breeding (harboring 12 species followed by river margins (five species and temporary pools and springs (four species each. During this study Ae. aegypti was recovered from tyres in Mingora; it was not reported earlier from Swat.

  10. Impacts of the creation, expansion and management of English wetlands on mosquito presence and abundance - developing strategies for future disease mitigation.

    Science.gov (United States)

    Medlock, Jolyon M; Vaux, Alexander G C

    2015-01-01

    The incidence of mosquito-borne diseases is increasing in Europe, partly due to the incursion of a number of invasive species known to be vectors of dengue and chikungunya viruses, but also due to the involvement of native species in the transmission of West Nile virus and malaria. For some of these pathogens, there is a risk of the re-emergence of vector-borne diseases that were once widespread in Europe, but declined partly due to large-scale land-drainage projects. Some mosquito species exploit container habitats as breeding sites in urban areas; an adaptation to human-made micro-habitats resulting from increased urbanisation. However, many species thrive in natural wetland ecosystems. Owing to the impacts of climate change there is an urgent need for environmental adaptation, such as the creation of new wetlands to mitigate coastal and inland flooding. In some cases, these initiatives can be coupled with environmental change strategies to protect a range of endangered flora and fauna species by enhancing and extending wetland landscapes, which may by driven by European legislation, particularly in urban areas. This paper reviews field studies conducted in England to assess the impact of newly created wetlands on mosquito colonisation in a) coastal, b) urban and c) arable reversion habitats. It also considers the impact of wetland management on mosquito populations and explores the implications of various water and vegetation management options on the range of British mosquito species. Understanding the impact of wetland creation and management strategies on mosquito prevalence and the potential risk of increasing the levels of nuisance or disease vector species will be crucial in informing health and well-being risk assessments, guiding targeted control, and anticipating the social effects of extreme weather and climate change. Although new wetlands will certainly extend aquatic habitats for mosquitoes, not all species will become a major nuisance or a vector concern as a result. Understanding how the design and management of wetlands might exacerbate mosquito densities is crucial if we are to manage nuisance mosquitoes and control vector species in the event of a disease outbreak. This entomological evidence-base will ensure that control strategies achieve optimal efficacy at minimal cost. PMID:25889666

  11. Selection of mosquito life-histories: a hidden weapon against malaria?

    Directory of Open Access Journals (Sweden)

    Ferguson Heather M

    2012-04-01

    Full Text Available Abstract Background There has recently been a substantial decline in malaria incidence in much of Africa. While the decline can clearly be linked to increasing coverage of mosquito vector control interventions and effective drug treatment in most settings, the ubiquity of reduction raises the possibility that additional ecological and associated evolutionary changes may be reinforcing the effectiveness of current vector control strategies in previously unanticipated ways. Presentation of hypothesis Here it is hypothesized that the increasing coverage of insecticide-treated bed nets and other vector control methods may be driving selection for a shift in mosquito life history that reduces their ability to transmit malaria parasites. Specifically it is hypothesized that by substantially increasing the extrinsic rate of mortality experienced in vector populations, these interventions are creating a fitness incentive for mosquitoes to re-allocate their resources towards greater short-term reproduction at the expense of longer-term survival. As malaria transmission is fundamentally dependent on mosquito survival, a life history shift in this direction would greatly benefit control. Testing the hypothesis At present, direct evaluation of this hypothesis within natural vector populations presents several logistical and methodological challenges. In the meantime, many insights can be gained from research previously conducted on wild Drosophila populations. Long-term selection experiments on these organisms suggest that increasing extrinsic mortality by a magnitude similar to that anticipated from the up-scaling of vector control measures generated an increase in their intrinsic mortality rate. Although this increase was small, a change of similar magnitude in Anopheles vector populations would be predicted to reduce malaria transmission by 80%. Implications of hypothesis The hypothesis presented here provides a reminder that evolutionary processes induced by interventions against disease vectors may not always act to neutralize intervention effectiveness. In the search for new intervention strategies, consideration should be given to both the potential disadvantages and advantages of evolutionary processes resulting from their implementation, and attempts made to exploit those with greatest potential to enhance control.

  12. Multiple receptors as targets of Cry toxins in mosquitoes.

    Science.gov (United States)

    Likitvivatanavong, Supaporn; Chen, Jianwu; Evans, Amy M; Bravo, Alejandra; Soberon, Mario; Gill, Sarjeet S

    2011-04-13

    Bacillus thuringiensis (Bt) produces inclusions that are composed of proteins known as crystal proteins or Cry toxins. Due to their high specificity and their safety to humans and the environment, these Cry toxins are considered to be valuable alternatives to chemical pesticides in insect control programs. It is believed that Cry toxin-induced membrane pore formation is responsible for insect toxicity. The molecular mechanism of pore formation involves recognition and subsequent binding of the tox