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Mosquito Control  

Science.gov (United States)

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HERBAL CONTROL OF MOSQUITO LARVAE  

Directory of Open Access Journals (Sweden)

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.

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

2013-04-01

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Insecticide-resistant mosquitoes and malaria control.  

Science.gov (United States)

The emergence of insecticide-resistant mosquitoes strongly challenges the fight against mosquito-borne diseases, in particular malaria. In this paper, we formulate a system of nonlinear difference equations for malaria transmission cycle. Our model incorporates compartments for insecticide-resistant mosquitoes, where mutation is the only evolutionary force involved in the occurrence of resistant allele in the mosquito population. By deriving an epidemiological threshold, the global stability of the disease and the resistance-free fixed point is established for reduced recruitment rates of resistant mosquitoes. Furthermore, by employing numerical techniques, we showed that the mosquito-human transmission cycle of malaria and its prevalence could be impacted by mutation rate, the personal protection of hosts and the density of mosquitoes. Our results highlight that given a large mosquito population, the presence of even a small number of resistant mosquitoes to an insecticide could make the insecticide ineffective for malaria control. This suggests the need for effective insecticide management strategy, alternate mosquito control approaches, educating the public about personal protection and reduction of mosquito population in a given environment. PMID:24657875

Blayneh, Kbenesh W; Mohammed-Awel, Jemal

2014-06-01

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North American Wetlands and Mosquito Control  

Directory of Open Access Journals (Sweden)

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.

Gabrielle E. Sakolsky-Hoopes

2012-12-01

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North American Wetlands and Mosquito Control  

Science.gov (United States)

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

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

2012-01-01

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Entomopathogenic fungi for mosquito control: A review  

Directory of Open Access Journals (Sweden)

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.

Ernst-Jan Scholte

2004-06-01

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MODELING AND BIOLOGICAL CONTROL OF MOSQUITOES  

OpenAIRE

Models can be useful at many different levels when considering complex issues such as biological control of mosquitoes. At an early stage, exploratory models are valuable in exploring the characteristics of an ideal biological control agent and for guidance in data collection. When more data are available, models can be used to explore alternative control strategies and the likelihood of success. There are few modeling studies that explicitly consider biological control in mosquitoes; however...

Lord, Cynthia C.

2007-01-01

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Potential of medicinal plants in mosquito control.  

Science.gov (United States)

Medicinal plants have long history as important components in traditional medicine, and food of humans since ancient Egyptians and Chinese. Naturally occurring botanical compounds contain a broad range of chemical active ingredients can intervene in all biological processes of the mosquito, thus interrupt its life cycle and dispersal and reduce harms to humans and animals. Many medicinal plants were tested for their pesticide and repellent potential, as crude material, essential oils or individual active ingredients. This article reviewed studies on the efficacy of many well known and commonly used safe medicinal plants or their products in controlling the mosquitoes; Aedes aegypti, Anopheles gambiae, An. stephensi and Culex quinquefasciatus and the ticks, Dermacentor variabilis, Amblyomma americanum, Ixodes scapularis and I. ricinus. Promising and encouraging results were obtained against these arthropod-vectors of zoonotic diseases. PMID:20503582

Fallatah, Sahar A B; Khater, Emad I M

2010-04-01

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 intern

André Barretto Bruno, Wilke; Mauro Toledo, Marrelli.

2012-10-01

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

Directory of Open Access Journals (Sweden)

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

André Barretto Bruno Wilke

2012-10-01

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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)

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EFFICACY OF AGERATUM CONYZOIDES AGAINST THE CONTROL OF MOSQUITOES  

OpenAIRE

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. ...

Neetu Arya et al.

2011-01-01

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Control of mosquito breeding through Gambusia affinis in rice fields.  

Science.gov (United States)

Studies on mosquito breeding and its control through Gambusia affinis in nursery and paddy fields after transplantation of seedlings were carried out during June to October 1991 in about 10 ha rice field area. Six anopheline species, viz. An. culicifacies, An. annularis, An. subpictus, An. nigerrimus, An. barbirostris and An. aconitus, and four culicine species, viz. Cx. tritaeniorhynchus, Cx. bitaeniorhynchus, Cx. quinquefasciatus, and Aedes sp. could be identified. These were found breeding in rice fields with fluctuations in their percentage composition, exhibiting species succession in different months. G. affinis survived well in submerged rice fields and provided 87.8% mosquito larval control. In rice fields which exhibited intermittent drying up leading to formation of pools, puddles etc., moderate larval control was achieved. However, in nursery rice fields, this method was not applicable. Mosquito larval control through larvivorous fish in rice fields can be achieved but the method has limitations. PMID:8405595

Prasad, H; Prasad, R N; Haq, S

1993-06-01

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An incident of fenthion mosquito control and subsequent avian mortality  

Science.gov (United States)

Mass mortality among migratory birds at Grand Forks, North Dakota, was attributed to a mosquito control operation employing the insecticide fenthion. The factors involved may have included the toxicity of the pesticide for birds, the method of application and coincidence with the peak of the spring warbler migration.

Seabloom, R.W.; Pearson, G.L.; Oring, L.W.; Reilly, J.R.

1973-01-01

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Novel Selective and Irreversible Mosquito Acetylcholinesterase Inhibitors for Controlling Malaria and Other Mosquito-Borne Diseases  

Science.gov (United States)

We reported previously that insect acetylcholinesterases (AChEs) could be selectively and irreversibly inhibited by methanethiosulfonates presumably through conjugation to an insect-specific cysteine in these enzymes. However, no direct proof for the conjugation has been published to date, and doubts remain about whether such cysteine-targeting inhibitors have desirable kinetic properties for insecticide use. Here we report mass spectrometric proof of the conjugation and new chemicals that irreversibly inhibited African malaria mosquito AChE with bimolecular inhibition rate constants (kinact/KI) of 3,604-458,597 M-1sec-1 but spared human AChE. In comparison, the insecticide paraoxon irreversibly inhibited mosquito and human AChEs with kinact/KI values of 1,915 and 1,507 M-1sec-1, respectively, under the same assay conditions. These results further support our hypothesis that the insect-specific AChE cysteine is a unique and unexplored target to develop new insecticides with reduced insecticide resistance and low toxicity to mammals, fish, and birds for the control of mosquito-borne diseases.

Dou, Dengfeng; Park, Jewn Giew; Rana, Sandeep; Madden, Benjamin J.; Jiang, Haobo; Pang, Yuan-Ping

2013-01-01

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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

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Mosquito Surveillance for Prevention and Control of Emerging Mosquito-Borne Diseases in Portugal — 2008–2014  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program—REVIVE (REde de VIgilância de VEctores—has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV and other flaviviruses in adult mosquitoes is continuously performed. Adult mosquitoes—collected mainly with Centre for Disease Control light traps baited with CO2—and larvae were systematically collected from a wide range of habitats in 20 subregions (NUTS III. Around 500,000 mosquitoes were trapped in more than 3,000 trap nights and 3,500 positive larvae surveys, in which 24 species were recorded. The viral activity detected in mosquito populations in these years has been limited to insect specific flaviviruses (ISFs non-pathogenic to humans. Rather than emergency response, REVIVE allows timely detection of changes in abundance and species diversity providing valuable knowledge to health authorities, which may take control measures of vector populations reducing its impact on public health. This work aims to present the REVIVE operation and to expose data regarding mosquito species composition and detected ISFs.

Hugo C. Osório

2014-11-01

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Mosquito surveillance for prevention and control of emerging mosquito-borne diseases in Portugal - 2008-2014.  

Science.gov (United States)

Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program-REVIVE (REde de VIgilância de VEctores)-has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV) and other flaviviruses in adult mosquitoes is continuously performed. Adult mosquitoes-collected mainly with Centre for Disease Control light traps baited with CO2-and larvae were systematically collected from a wide range of habitats in 20 subregions (NUTS III). Around 500,000 mosquitoes were trapped in more than 3,000 trap nights and 3,500 positive larvae surveys, in which 24 species were recorded. The viral activity detected in mosquito populations in these years has been limited to insect specific flaviviruses (ISFs) non-pathogenic to humans. Rather than emergency response, REVIVE allows timely detection of changes in abundance and species diversity providing valuable knowledge to health authorities, which may take control measures of vector populations reducing its impact on public health. This work aims to present the REVIVE operation and to expose data regarding mosquito species composition and detected ISFs. PMID:25396768

Osório, Hugo C; Zé-Zé, Líbia; Amaro, Fátima; Alves, Maria J

2014-11-01

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Challenges and Approaches for Mosquito Targeted Malaria Control  

OpenAIRE

Malaria is one of today’s most serious diseases with an enormous socioeconomic impact. While anti-malarial drugs have existed for some time and vaccines development may be underway, the most successful malaria eradication programs have thus far relied on attacking the mosquito vector that spreads the disease causing agent Plasmodium. Here we will review past, current and future perspectives of malaria vector control strategies and how these approaches have taken a promising turn thanks rece...

Ramirez, Jose? L.; Garver, Lindsey S.; Dimopoulos, George

2009-01-01

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

OpenAIRE

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...

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

2010-01-01

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Challenges and approaches for mosquito targeted malaria control.  

Science.gov (United States)

Malaria is one of today's most serious diseases with an enormous socioeconomic impact. While anti-malarial drugs have existed for some time and vaccines development may be underway, the most successful malaria eradication programs have thus far relied on attacking the mosquito vector that spreads the disease causing agent Plasmodium. Here we will review past, current and future perspectives of malaria vector control strategies and how these approaches have taken a promising turn thanks recent advances in functional genomics and molecular biology. PMID:19275622

Ramirez, José L; Garver, Lindsey S; Dimopoulos, George

2009-03-01

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Aerial and Tidal Transport of Mosquito Control Pesticides into the Florida Keys National Marine Sanctuary  

OpenAIRE

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 persistence 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 ...

Pierce, R. H.; Henry, M. S.; Blum, T. C.; Mueller, E. M.

2005-01-01

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EFFICACY OF AGERATUM CONYZOIDES AGAINST THE CONTROL OF MOSQUITOES  

Directory of Open Access Journals (Sweden)

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.

Neetu Arya et al.

2011-12-01

24

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

Science.gov (United States)

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

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

2015-01-01

25

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

Science.gov (United States)

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 discussions, and personal communication. SWOT analysis identified various issues affecting the efficiency and sustainability of mosquito control operations. The main outcome of our work was the description and comparison of mosquito control operations within the context of each study site's biological, social, political, management, and economic conditions. The issues identified in this study ranged from lack of inter-sector collaboration to operational issues of mosquito control efforts. A lack of sustainable funding for mosquito control was a common problem for most sites. Many unique problems were also identified, which included lack of mosquito surveillance, lack of law enforcement, and negative consequences of human behavior. Identifying common virtues and shortcomings of mosquito control operations is useful in identifying "best practices" for mosquito control operations, thus leading to better control of mosquito biting and mosquito-borne disease transmission. PMID:17316882

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; Calderón-Arguedas, Olger; Sánchez-Loría, Victoria M; Velit-Suarez, Rosanna; Chadee, Dave D; Novak, Robert J; Beier, John C

2007-10-01

26

Late-acting dominant lethal genetic systems and mosquito control  

Directory of Open Access Journals (Sweden)

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

Scaife Sarah

2007-03-01

27

Community Knowledge and Experience of Mosquitoes and Personal Prevention and Control Practices in Lhasa, Tibet  

Directory of Open Access Journals (Sweden)

Full Text Available Since 2009, great public attention has been paid in Lhasa City (Tibet, China to mosquito bites and accompanying inflammatory complications. However, the potential contribution of knowledge levels, experiences, disease control and preventive practices (KEP towards mosquitoes has not received much attention. To investigate community KEP concerning mosquitoes in Lhasa, a cross-sectional survey was undertaken in four sub-districts of urban Lhasa in 2012. Questionnaires were designed to collect information regarding socio-demographics and KEP concerning the harmful effects of mosquitoes on participants. The scoring for KEP was developed after consultation of literature. A total of 591 eligible questionnaires were examined. The majority of respondents were female (61.8% with a mean age of 46 years. Nearly all of the respondents were of Tibetan nationality (97.4% and living in registered native households (92.7%, who have less than primary school education. The averages of overall score, knowledge score, experience score, and practice score were 9.23, 4.53, 1.80, 2.90, respectively. The registered household with the highest overall score, knowledge score and practice score was non-native. Female subjects with monthly incomes between 1000 and 3000 RMB had higher experience scores. The correlation analysis revealed that significant positive linear correlations existed between knowledge and experience, knowledge and practices, and experience and practices towards mosquitoes. Past experiences with mosquitoes can result in a better knowledge of effective mosquito control practices in the present and the future. Though the average of overall scores related to mosquitoes is high among the participants in Lhasa, however, the knowledge about the ecological habits of mosquitoes should be strengthened. The findings in this study may help to develop strategies and measures of mosquito and mosquito-borne diseases in the future, not only in Lhasa, but also in similar altitude, latitude and longitude regions worldwide.

Xiaobo Liu

2014-09-01

28

Mosquito Surveillance for Prevention and Control of Emerging Mosquito-Borne Diseases in Portugal — 2008–2014  

OpenAIRE

Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program—REVIVE (REde de VIgilância de VEctores)—has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV) and other flaviviruses in a...

Oso?rio, Hugo C.; Líbia Zé-Zé; Fátima Amaro; Alves, Maria J.

2014-01-01

29

Crustacean biodiversity as an important factor for mosquito larval control.  

Science.gov (United States)

Newly established ponds, which are highly dynamic systems with changing levels of biological interactions among species, are common larval mosquito habitats. We investigated the impact of crustacean abundance and taxa diversity on mosquito oviposition and larval development. The effects of the biological larvicide Bacillus thuringiensis israelensis (Bti) on mosquito larvae were monitored according to fluctuations in crustacean communities. Populations of the mosquito Culex pipiens colonized artificial ponds that contained crustacean communities at different time points of colonization by crustaceans: 1) 'no colonization' (no crustaceans), 2) 'simultaneous colonization' by crustaceans and mosquitoes, and 3) 'head-start colonization' by crustaceans (preceding colonization by mosquitoes). All types of ponds were treated with three concentrations of Bti (10, 100, or 1,000 µg/liter). Colonization of all ponds by Cx. pipiens (in terms of oviposition, larval abundance, and larval development) decreased significantly with increasing diversity of crustacean taxa. The total abundance of crustaceans had a minor effect on colonization by Cx. pipiens. The presence of crustaceans increased the sensitivity of Cx. pipiens larvae to Bti treatment by a factor of 10 and delayed the time of recolonization. This effect of Bti was relevant in the short term. In the long term, the presence of Cx. pipiens was determined by crustacean biodiversity. PMID:24581370

Kroeger, Iris; Duquesne, Sabine; Liess, Matthias

2013-12-01

30

Selective and Irreversible Inhibitors of Mosquito Acetylcholinesterases for Controlling Malaria and Other Mosquito-Borne Diseases  

OpenAIRE

New insecticides are urgently needed because resistance to current insecticides allows resurgence of disease-transmitting mosquitoes while concerns for human toxicity from current compounds are growing. We previously reported the finding of a free cysteine (Cys) residue at the entrance of the active site of acetylcholinesterase (AChE) in some insects but not in mammals, birds, and fish. These insects have two AChE genes (AP and AO), and only AP-AChE carries the Cys residue. Most of these inse...

Pang, Yuan-ping; Ekstro?m, Fredrik; Polsinelli, Gregory A.; Gao, Yang; Rana, Sandeep; Hua, Duy H.; Andersson, Bjo?rn; Andersson, Per Ola; Peng, Lei; Singh, Sanjay K.; Mishra, Rajesh K.; Zhu, Kun Yan; Fallon, Ann M.; Ragsdale, David W.; Brimijoin, Stephen

2009-01-01

31

Effects on birds of fenthion aerial application for mosquito control  

Science.gov (United States)

Effects on birds of an aerial application of fenthion, a potent organophosphorus cholinesterase (ChE)-inhibiting insecticide, were assessed on four study sites 1.8 to 3.6 km2 in size. These sites were located within 121.5 km2 of wet meadows treated with 47 g of fenthion (AI) per ha in ultralow- volume formulation. Assessment methods were searches for sick or dead birds, measurements of brain ChE activity in specimens found dead or collected alive at different time intervals, and counts of bird populations. After treatment, 99 birds and 15 mammals were found sick or dead; 106 of these were on one site. Brain ChE activity in dead birds was depressed sufficiently to indicate that death was caused by an anti-ChE substance. Brain ChE activity in three common bird species collected alive showed the greatest reduction 2 days postspray. Two of these species had ChE activity that was still significantly (PFenthion sprayed for mosquito control was life threatening to many birds inhabiting treated meadows.

DeWeese, L.R.; McEwen, L.C.; Settimi, L.A.; Deblinger, R.D.

1983-01-01

32

High-throughput sorting of mosquito larvae for laboratory studies and for future vector control interventions  

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Full Text Available Abstract Background Mosquito transgenesis offers new promises for the genetic control of vector-borne infectious diseases such as malaria and dengue fever. Genetic control strategies require the release of large number of male mosquitoes into field populations, whether they are based on the use of sterile males (sterile insect technique, SIT or on introducing genetic traits conferring refractoriness to disease transmission (population replacement. However, the current absence of high-throughput techniques for sorting different mosquito populations impairs the application of these control measures. Methods A method was developed to generate large mosquito populations of the desired sex and genotype. This method combines flow cytometry and the use of Anopheles gambiae transgenic lines that differentially express fluorescent markers in males and females. Results Fluorescence-assisted sorting allowed single-step isolation of homozygous transgenic mosquitoes from a mixed population. This method was also used to select wild-type males only with high efficiency and accuracy, a highly desirable tool for genetic control strategies where the release of transgenic individuals may be problematic. Importantly, sorted males showed normal mating ability compared to their unsorted brothers. Conclusions The developed method will greatly facilitate both laboratory studies of mosquito vectorial capacity requiring high-throughput approaches and future field interventions in the fight against infectious disease vectors.

Marois Eric

2012-08-01

33

Adverse assessments of Gambusia affinis: an alternate view for mosquito control practitioners.  

Science.gov (United States)

Adverse opinions on the introduction of Gambusia affinis for the control of larval mosquitoes are reviewed. The sources span a period of some 59 years and come from a variety of sources. The principal opposition to the introduction of G. affinis comes from ichthyologists, although some mosquito researchers have expressed concerns about the environmental impact of placing the fish in habitats to which it is not native. Questions concerning the appropriateness of using the fish are presented. PMID:8827587

Rupp, H R

1996-06-01

34

Quantitative Trait Loci Mapping of Genome Regions Controlling Permethrin Resistance in the Mosquito Aedes aegypti  

OpenAIRE

The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Permethrin is an insecticide used to suppress Ae. aegypti adult populations but metabolic and target site resistance to pyrethroids has evolved in many locations worldwide. Quantitative trait loci (QTL) controlling permethrin survival in Ae. aegypti were mapped in an F3 advanced intercross line. Parents came from a collection of mosquitoes from Isla Mujeres, México, that had been selected for permethr...

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

2008-01-01

35

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

OpenAIRE

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...

Koella Jacob C; Boëte Christophe

2002-01-01

36

Diffusion Model On The Efficacy Of Larvicide In Antilarval Operation Of Mosquito Control  

Science.gov (United States)

Mosquito control is being performed under chemical, biological and genetic and altogether it is called integrated vector control. In developing countries like India, chemical control has been given priority. Chemicals used as adulticide is becoming resistance among mosquitoes compared to larvicide. Further, the destruction of immature (larvae) stages of mosquitoes is as effective as its distribution is limited whereas adult mosquitoes turned to terrestrial mode of life and its distribution is based on its flight range, habitat, aggregation of man and animals. In this research paper, selective spray treatment over larvae of mosquitoes of a semi-infinite pool is analyzed using diffusion model. Spray chemical is conceived to spread on the surface with time and in space. A critical concentration of spray chemical is envisaged for assumed death of mosquito larvae. Diffusion is modeled Fick' law. Spray losses are lumped into a first order term. Analytical solution of the resulting partial differential equation for various values of diffusivity and loss rate constant are plotted and interpreted. The model would be useful to appraise beforehand how far and for how long spray would be effective and how much of spray chemical is required for effectiveness within specified distance and time.

Basker, P.; Kumar, T. Ramesh; Prabu, S. Milton; Hemalatha, S.; Elango, S.; Padmanabhan, P.; Asokan, R.

2008-01-01

37

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

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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.

M. Palaniyandi

2014-09-01

38

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

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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.

Famenini Shannon

2010-05-01

39

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

OpenAIRE

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...

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

40

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

41

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

Directory of Open Access Journals (Sweden)

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.

Regis Lêda

2000-01-01

42

Evaluation of the control of mosquitoes with insect growth regulators.  

Science.gov (United States)

In this study, the effectiveness of eight insect growth regulators (IGRs) (chlorfluazuron, diflubenzuron, EL-494, flufenoxuron, teflubenzuron, juglone, plumbagin and methoprene) against five mosquito vectors (Armigeres subalbatus, Aedes albopictus, Aedes aegypti, Culex tritaeniorhynchus, and Culex quinquefasciatus) was investigated in the laboratory. The EC50s of chlorfluazuron, diflubenzuron, EL-494, flufenoxuron, teflubenzuron, and methoprene against the five mosquitoes ranged from 0.0001 to 0.3 ppm and those of juglone and plumbagin from 3-25 ppm. The five mosquito species had similar tolerances to the test IGRs. At pH 5 to 9, the effectiveness of the first five chemicals was very stable. After ultraviolet irradiation or heat management (45 degrees C-60 degrees C), diflubenzuron and flufenoxuron were very stable. EL-494 was not stable when exposed to ultraviolet irradiation or heat. Under 0.1 ppm, teflubenzuron was not stable upon exposure to heat and chlorfluazuron and methoprene were not stable when exposed to ultraviolet irradiation. Piperonyl butoxide reduces the effectiveness of the five IGRs. Administration of diflubenzuron (1-5 ppm), flufenoxuron (0.025 ppm), and teflubenzuron (1-5 ppm) reduced Culex quinquefasciatus larvae in ditches by 40-90%. The administration of diflubenzuron (0.5 ppm) to containers reduced 97% of the Aedes albopictus larvae. PMID:2402025

Ho, C M; Wu, S H; Wu, C C

1990-07-01

43

Cost-benefit analysis of an 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 (Asian tiger mosquito), which limit outdoor activities. We conducted a cost-benefit analysis for an AWPM in Mercer and Monmouth counties, New Jersey, as part of a controlled design with matched area...

44

A synthetic sex ratio distortion system for the control of the human malaria mosquito  

Science.gov (United States)

It has been theorized that inducing extreme reproductive sex ratios could be a method to suppress or eliminate pest populations. Limited knowledge about the genetic makeup and mode of action of naturally occurring sex distorters and the prevalence of co-evolving suppressors has hampered their use for control. Here we generate a synthetic sex distortion system by exploiting the specificity of the homing endonuclease I-PpoI, which is able to selectively cleave ribosomal gene sequences of the malaria vector Anopheles gambiae that are located exclusively on the mosquito’s X chromosome. We combine structure-based protein engineering and molecular genetics to restrict the activity of the potentially toxic endonuclease to spermatogenesis. Shredding of the paternal X chromosome prevents it from being transmitted to the next generation, resulting in fully fertile mosquito strains that produce >95% male offspring. We demonstrate that distorter male mosquitoes can efficiently suppress caged wild-type mosquito populations, providing the foundation for a new class of genetic vector control strategies. PMID:24915045

Galizi, Roberto; Doyle, Lindsey A.; Menichelli, Miriam; Bernardini, Federica; Deredec, Anne; Burt, Austin; Stoddard, Barry L.; Windbichler, Nikolai; Crisanti, Andrea

2014-01-01

45

Sterile-insect methods for control of mosquito-borne diseases: an analysis.  

Science.gov (United States)

Effective vector control, and more specifically mosquito control, is a complex and difficult problem, as illustrated by the continuing prevalence (and spread) of mosquito-transmitted diseases. The sterile insect technique and similar methods control certain agricultural insect pest populations in a species-specific, environmentally sound, and effective manner; there is increased interest in applying this approach to vector control. Such an approach, like all others in use and development, is not a one-size-fits-all solution, and will be more appropriate in some situations than others. In addition, the proposed release of pest insects, and more so genetically modified pest insects, is bound to raise questions in the general public and the scientific community as to such a method's efficacy, safety, and sustainability. This article attempts to address these concerns and indicate where sterile-insect methods are likely to be useful for vector control. PMID:19725763

Alphey, Luke; Benedict, Mark; Bellini, Romeo; Clark, Gary G; Dame, David A; Service, Mike W; Dobson, Stephen L

2010-04-01

46

Multiple resistances and complex mechanisms of Anopheles sinensis mosquito: a major obstacle to mosquito-borne diseases control and elimination in China.  

Science.gov (United States)

Malaria, dengue fever, and filariasis are three of the most common mosquito-borne diseases worldwide. Malaria and lymphatic filariasis can occur as concomitant human infections while also sharing common mosquito vectors. The overall prevalence and health significance of malaria and filariasis have made them top priorities for global elimination and control programmes. Pyrethroid resistance in anopheline mosquito vectors represents a highly significant problem to malaria control worldwide. Several methods have been proposed to mitigate insecticide resistance, including rotational use of insecticides with different modes of action. Anopheles sinensis, an important malaria and filariasis vector in Southeast Asia, represents an interesting mosquito species for examining the consequences of long-term insecticide rotation use on resistance. We examined insecticide resistance in two An. Sinensis populations from central and southern China against pyrethroids, organochlorines, organophosphates, and carbamates, which are the major classes of insecticides recommended for indoor residual spray. We found that the mosquito populations were highly resistant to the four classes of insecticides. High frequency of kdr mutation was revealed in the central population, whereas no kdr mutation was detected in the southern population. The frequency of G119S mutation in the ace-1 gene was moderate in both populations. The classification and regression trees (CART) statistical analysis found that metabolic detoxification was the most important resistance mechanism, whereas target site insensitivity of L1014 kdr mutation played a less important role. Our results indicate that metabolic detoxification was the dominant mechanism of resistance compared to target site insensitivity, and suggests that long-term rotational use of various insecticides has led An. sinensis to evolve a high insecticide resistance. This study highlights the complex network of mechanisms conferring multiple resistances to chemical insecticides in mosquito vectors and it has important implication for designing and implementing vector resistance management strategies. PMID:24852174

Chang, Xuelian; Zhong, Daibin; Fang, Qiang; Hartsel, Joshua; Zhou, Guofa; Shi, Linna; Fang, Fujin; Zhu, Changliang; Yan, Guiyun

2014-05-01

47

Biorational insecticides for control of mosquitoes and black flies in Sinaloa  

OpenAIRE

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 ob...

Cipriano García Gutiérrez; Rosa Luz Gómez Peraza; Lo?pez Aguilar, Claudia E.; Arturo León Váldez

2012-01-01

48

Sustainable control of mosquito larvae in the field by the combined actions of the biological insecticide Bti and natural competitors.  

Science.gov (United States)

Integrated management of mosquitoes is becoming increasingly important, particularly in relation to avoiding recolonization of ponds after larvicide treatment. We conducted for the first time field experiments that involved exposing natural populations of the mosquito species Culex pipiens to: a) application of the biological insecticide Bacillus thuringiensis israelensis (Bti), b) the introduction of natural competitors (a crustacean community composed mainly of Daphnia spp.), or c) a combined treatment that involved both introduction of a crustacean community and the application of Bti. The treatment that involved only the introduction of crustaceans had no significant effect on mosquito larval populations, while treatment with Bti alone caused only a significant reduction in the abundance of mosquito larvae in the short-term (within 3-10 days after treatment). In contrast, the combined treatment rapidly reduced the abundance of mosquito larvae, which remained low throughout the entire observation period of 28 days. Growth of the introduced crustacean communities was favored by the immediate reduction in the abundance of mosquito larvae following Bti administration, thus preventing recolonization of ponds by mosquito larvae at the late period (days 14-28 after treatment). Both competition and the temporal order of establishment of different species are hence important mechanisms for efficient and sustainable mosquito control. PMID:23701611

Kroeger, Iris; Liess, Matthias; Dziock, Frank; Duquesne, Sabine

2013-06-01

49

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

Science.gov (United States)

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

Crisanti, Andrea

2013-12-01

50

Achieving high coverage of larval-stage mosquito surveillance: challenges for a community-based mosquito control programme in urban Dar es Salaam, Tanzania  

OpenAIRE

Abstract Background Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP) in urban Dar es Salaam, Tanzania. Methods Cross-sectional surveys were carried out to assess the ability of community-owned resource per...

Shoo Bryson; Govella Nicodem J; Chaki Prosper P; Hemed Abdullah; Tanner Marcel; Fillinger Ulrike; Killeen Gerry F

2009-01-01

51

Comparative efficacy of the threespine stickleback (Gasterosteus aculeatus) and the mosquitofish (Gambusia affinis) for mosquito control.  

Science.gov (United States)

The effectiveness of the threespine stickleback as a mosquito control agent was compared to that of the mosquitofish in 28-m2 earthen ponds during 26-wk experiments where the 2 fish were stocked alone and together. Relative to ponds without fish, the stickleback was not effective for controlling larval mosquito populations; however, sticklebacks reduced the abundance of Culex pupae. Mosquitofish provided significant levels of control whether stocked alone or concurrently with the stickleback. As compared to mosquitofish alone, mosquito control was not significantly enhanced when both fish were stocked together. Mortality of adult sticklebacks was related to a gradient of increasing water temperature across the ponds rather than the direct effects of other abiotic factors such as low dissolved oxygen concentrations or biotic interactions with the mosquitofish. The stickleback exhibited a lower thermal tolerance and slower population recruitment as compared to the mosquitofish populations,which reproduced successfully in water > 33 degrees C and grew rapidly. Stickleback biomass either declined or increased slightly (approximately 50% of initial stocking weight). Mosquitofish biomass increased 33- to 38-fold at rates averaging between 0.079 and 0.095 g wet weight/g/day and total wet weight per pond at 6 wk after stocking did not differ significantly between the 2 mosquitofish treatments. PMID:10480131

Offill, Y A; Walton, W E

1999-09-01

52

Investigating preferences for mosquito-control technologies in Mozambique with latent class analysis  

OpenAIRE

Abstract Background It is common practice to seek the opinions of future end-users during the development of innovations. Thus, the aim of this study is to investigate latent classes of users in Mozambique based on their preferences for mosquito-control technology attributes and covariates of these classes, as well as to explore which current technologies meet these preferences. Methods Surveys were administered in five rural villages in Mozambique. The data wer...

Barclay Victoria C; Smith Rachel A; Findeis Jill L

2011-01-01

53

Characteristics of mangrove swamps managed for mosquito control in eastern Florida, USA  

Science.gov (United States)

Manipulations of the vegetation and hydrology of wetlands for mosquito control are common worldwide, but these modifications may affect vital ecosystem processes. To control mosquitoes in mangrove swamps in eastern Florida, managers have used rotational impoundment management (RIM) as an alternative to the worldwide practice of mosquito ditching. Levees surround RIM swamps, and water is pumped into the impoundment during the summer, a season when natural swamps have low water levels. In the New World, these mosquito-managed swamps resemble the mixed basin type of mangrove swamp (based on PCA analysis). An assessment was made of RIM, natural (control), and breached-RIM (restored) swamps in eastern Florida to compare their structural complexities, soil development, and resistance to invasion. Regarding structural complexity, dominant species composition differed between these swamps; the red mangrove Rhizophora mangle occurred at a higher relative density in RIM and breached-RIM swamps, and the black mangrove Avicennia germinans had a higher relative density in natural swamps. Tree density and canopy cover were higher and tree height lower in RIM swamps than in natural and breached-RIM swamps. Soil organic matter in RIM swamps was twice that in natural or breached-RIM swamps. RIM swamps had a lower resistance to invasion by the Brazilian pepper tree Schinus terebinthifolius, which is likely attributable to the lower porewater salinity in RIM swamps. These characteristics may reflect differences in important ecosystem processes (primary production, trophic structure, nutrient cycling, decomposition). Comparative assessments of managed wetlands are vital for land managers, so that they can make informed decisions compatible with conservation objectives. ?? Inter-Research 2008.

Middleton, B.; Devlin, D.; Proffitt, E.; McKee, K.; Cretini, K.F.

2008-01-01

54

Identification and characterization of a novel marine Bacillus cereus for mosquito control.  

Science.gov (United States)

Entomopathogenic bacteria to control mosquitoes are a promising environmentally friendly alternative to synthetic pesticides. In the present study, a novel mosquitocidal bacterium was isolated from marine soil collected from east coastal areas at Pondicherry (India). 16S rRNA gene sequence alignment depicted that this isolate belonged to Bacillus cereus VCRC-B520 (NCBI: KC-119192). Biochemical studies on bacterial growth, biomass, and toxin production have revealed that this strain could possibly be helpful in the production of a biopesticide in mosquito control. Toxicity assay with B. cereus against mosquito larvae has shown that the filariasis vector, Culex quinquefasciatus, is more susceptible than the other two species (Anopheles stephensi and Aedes aegypti). The LC50 and LC90 values for C. quinquefasciatus were 0.30 and 2.21 mg/L, respectively. No effect of B. cereus was found on nontargeted organisms. SDS-PAGE analysis and protein purification result from the cell mass of B. cereus have shown that a well-perceptible polypeptide was the dependable factor (85 kDa) for mosquitocidal action. Protein characterization (M/S MALDI-TOF) has shown that it is an endotoxin-specific insecticidal protein, namely "Cry4Aa". Phylogenetic analyses of 16S rDNA gene sequence from this marine isolate have revealed the presence of homology among closely related Bacillus strains. Therefore, considerable interest has been shown on the identification of a potential mosquitocidal bacterium from marine environment (B. cereus), which was not reported earlier in view of the current scenario of the rapid development of resistance to Bacillus sphaericus in mosquito vector control program. PMID:24192866

Poopathi, Subbiah; Mani, C; Thirugnanasambantham, K; Praba, V Lakshmi; Ahangar, Niyaz Ahmad; Balagangadharan, K

2014-01-01

55

Insecticide substitutes for DDT to control mosquitoes may be causes of several diseases.  

Science.gov (United States)

Malaria continues to be a public health problem in Bangladesh, despite efforts in the 1960s to eradicate the vectors through the use of DDT. At one point, eradication of malaria was acclaimed but later on it reappeared. The use of DDT is no more legally allowed in Bangladesh, which has been officially replaced by a number organophosphates and/or synthetic pyrethroids and their combinations in addition to the integrated vector management (IVM) package. IVM being a community approach is still to go a long way to be mass popular. Adulticides, larvicides, residual sprays, mosquito coil, insecticide-impregnated curtain, aerosol, etc. still serve as the major weapons of mosquito control. Thus, mosquito control still mostly depends on chemical insecticides. Although the use of DDT is banned in Bangladesh, there are reports on its illegal use in different forms. Moreover, there is tons of leftover DDT in Bangladesh, which is likely to cause several diseases. As per one report, about 500 MTs of DDT stockpiles are lying in the Medical Sub-Depots at Chittagong for over a period of 26 years. DDT is a persistent organic pollutant pesticide, which can cause diseases like cancer, endocrine disorder, disruption of immune system, embryonic abnormality, reproductive disorder, etc. Other chemical insecticides, which are replacing DDT, are also not free of hazardous impacts. IVM thus appears to be a wise approach requiring concerted efforts for the management of mosquito to control malaria. Such an IVM comprises use of Bacillus thuringiensis Berliner var. israelensis, methoprene, biocontrol agents, cleaning of breeding sites, pyrethroid-impregnated curtain, etc. Therefore, a wise effort should be adopted to completely stop the use of DDT, eliminate its stockpiles wherever they are in Bangladesh and to popularise the IVM, not the chemicals-based alternatives throughout the country. PMID:22956113

Rahman, Md Mahbubar

2013-04-01

56

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

Science.gov (United States)

We determined the feasibility of using the BG-Sentinel™ mosquito trap (BGS) as the pull component in a push-pull strategy to reduce indoor biting by Aedes aegypti. This included evaluating varying numbers of traps (1-4) and mosquito release numbers (10, 25, 50, 100, 150, 200, and 250) on recapture rates under screen house conditions. Based on these variations in trap and mosquito numbers, release intervals were rotated through a completely randomized design with environmental factors (temperature, relative humidity, and light intensity) and monitored throughout each experiment. Data from four sampling time points (05:30, 09:30, 13:30, and 17:30) indicate a recapture range among treatments of 66-98%. Furthermore, 2-3 traps were as effective in recapturing mosquitoes as 4 traps for all mosquito release numbers. Time trends indicate Day 1 (the day the mosquitoes were released) as the "impact period" for recapture with peak numbers of marked mosquitoes collected at 09:30 or 4 h post-release. Information from this study will be used to guide the configuration of the BGS trap component of a push-pull vector control strategy currently in the proof-of-concept stage of development in Thailand and Peru. PMID:22548532

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

2012-06-01

57

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

OpenAIRE

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 app...

Dempsey Mary E; Iwanejko Tom; Rochlin Ilia; Ninivaggi Dominick V

2009-01-01

58

Potential Benefits, Limitations and Target Product-Profiles of Odor-Baited Mosquito Traps for Malaria Control in Africa  

OpenAIRE

BACKGROUND Traps baited with synthetic human odors have been proposed as suitable technologies for controlling malaria and other mosquito-borne diseases. We investigated the potential benefits of such traps for preventing malaria transmission in Africa and the essential characteristics that they should possess so as to be effective. METHODS AND PRINCIPAL FINDINGS An existing mathematical model was reformulated to distinguish availability of hosts for attack by mosquitoes from avai...

Okumu, Fredros O.; Govella, Nicodem J.; Moore, Sarah J.; Chitnis, Nakul; Killeen, Gerry F.

2010-01-01

59

Screening Mosquito House Entry Points as a Potential Method for Integrated Control of Endophagic Filariasis, Arbovirus and Malaria Vectors  

OpenAIRE

BACKGROUND Partial mosquito-proofing of houses with screens and ceilings has the potential to reduce indoor densities of malaria mosquitoes. We wish to measure whether it will also reduce indoor densities of vectors of neglected tropical diseases. METHODOLOGY The main house entry points preferred by anopheline and culicine vectors were determined through controlled experiments using specially designed experimental huts and village houses in Lupiro village, southern Tanzania. The b...

Ogoma, Sheila B.; Lweitoijera, Dickson W.; Ngonyani, Hassan; Furer, Benjamin; Russell, Tanya L.; Mukabana, Wolfgang R.; Killeen, Gerry F.; Moore, Sarah J.

2010-01-01

60

A tool box for operational mosquito larval control : preliminary results and early lessons from the Urban Malaria Control Program in Dar es Salaam, Tanzania.  

OpenAIRE

Background: As the population of Africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed. Methods: A recently initiated Urban Malaria Control Programme in Dar es Salaam delegates responsibility for routine mosquito control and surveillance to modestly-paid community members, known as Community-Owned Resource Persons (CORPs). New vector surveillance, ...

Fillinger, U.; Kannady, K.; William, G.; Vanek, M. J.; Dongus, S.; Nyika, D.; Geissbuehler, Y.; Chaki, P. P.; Govella, N. J.; Mathenge, E. M.; Singer, B. H.; Mshinda, H.; Lindsay, S. W.; Tanner, M.; Mtasiwa, D.

2008-01-01

61

A tool box for operational mosquito larval control: preliminary results and early lessons from the Urban Malaria Control Programme in Dar es Salaam, Tanzania.  

OpenAIRE

Abstract Background As the population of Africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed. Methods A recently initiated Urban Malaria Control Programme in Dar es Salaam delegates responsibility for routine mosquito control and surveillance to modestly-paid community members, known as Community-Owned Resource Persons (CORPs)...

Govella Nico J; Chaki Prosper P; Geissbühler Yvonne; Nyika Dickson; Dongus Stefan; Vanek Michael J; William George; Kannady Khadija; Fillinger Ulrike; Mathenge Evan M; Singer Burton H; Mshinda Hassan; Lindsay Steven W; Tanner Marcel; Mtasiwa Deo

2008-01-01

62

Monitoring the aquatic toxicity of mosquito vector control spray pesticides to freshwater receiving waters.  

Science.gov (United States)

Pesticides are applied to state and local waterways in California to control insects such as mosquitoes, which are known to serve as a vector for West Nile Virus infection of humans. The California State Water Resources Control Board adopted a National Pollutant Discharge Elimination System General Permit to address the discharge to waters of the United States of pesticides resulting from adult and larval mosquito control. Because pesticides used in spray activities have the potential to cause toxicity to nontarget organisms in receiving waters, the current study was designed to determine whether toxicity testing provides additional, useful environmental risk information beyond chemical analysis in monitoring spray pesticide applications. Monitoring included a combination of aquatic toxicity tests and chemical analyses of receiving waters from agricultural, urban, and wetland habitats. The active ingredients monitored included the organophosphate pesticides malathion and naled, the pyrethroid pesticides etofenprox, permethrin, and sumithrin, pyrethrins, and piperonyl butoxide (PBO). Approximately 15% of the postapplication water samples were significantly toxic. Toxicity of half of these samples was attributed to the naled breakdown product dichlorvos. Toxicity of 2 other water samples likely occurred when PBO synergized the effects of pyrethroid pesticides that were likely present in the receiving system. Four of 43 postapplication sediment samples were significantly more toxic than their corresponding pre-application samples, but none of the observed toxicity was attributed to the application events. These results indicate that many of the spray pesticides used for adult mosquito control do not pose significant acute toxicity risk to invertebrates in receiving systems. In the case of naled in water, analysis of only the active ingredient underestimated potential impacts to the receiving system, because toxicity was attributed to the breakdown product, dichlorvos. Toxicity testing can provide useful risk information about unidentified, unmeasured toxicants or mixtures of toxicants. In this case, toxicity testing provided information that could lead to the inclusion of dichlorvos monitoring as a permit requirement. PMID:24659580

Phillips, Bryn M; Anderson, Brian S; Voorhees, Jennifer P; Siegler, Katie; Denton, Debra; TenBrook, Patti; Larsen, Karen; Isorena, Philip; Tjeerdema, Ron S

2014-07-01

63

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

Directory of Open Access Journals (Sweden)

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.

Dempsey Mary E

2009-06-01

64

Comparison of mosquito control provided by the arroyo chub (Gila orcutti) and the mosquitofish (Gambusia affinis).  

Science.gov (United States)

Two 6-wk trials were conducted in 28-m2 earthen ponds to compare the efficacy of the arroyo chub, Gila orcutti, to the mosquitofish, Gambusia affinis, as a biological control agent for mosquitoes and a possible replacement for the mosquitofish in sensitive watersheds of southern California. The mosquitofish population growth rate was 1.73 times greater than the arroyo chub population growth rate; however, greater reproduction by the mosquitofish did not result in significantly better reduction of mosquitoes than was provided by the comparatively small populations of arroyo chub. On average across a 6-wk study in the spring, both larvivorous fishes reduced the abundance of 3rd and 4th instars by 4- to 5-fold compared to that observed in the control ponds that lacked fish but contained few invertebrate predators. The abundance of nontarget microinvertebrates in ponds containing the mosquitofish was only 7% of that in ponds containing the arroyo chub during the summer, but did not differ significantly between the fish species treatments when zooplankton was comparatively more abundant during the spring. Even though the number of individuals produced by each fish species during 6 wk in the spring was greater than for fish stocked in the summer, species-specific population growth rates in the spring study (individuals/individual/d; mosquitofish, 0.077; arroyo chub, 0.044) were only slightly higher than in the summer (individuals/individual/d; mosquitofish, 0.068; arroyo chub, 0.039) indicating that differences in the number of fish stocked contributed primarily to the differences in final population size between spring and summer studies. The arroyo chub is native to the South Coastal drainages in California and should be considered as a viable alternative to the mosquitofish for integrated mosquito management programs in riverine wetlands and sensitive watersheds of southern California. PMID:18240519

Van Dam, Alex R; Walton, William E

2007-12-01

65

Door to Door Survey and Community Participation to Implement a New County Mosquito Control Program in Wayne County, North Carolina, USA  

Directory of Open Access Journals (Sweden)

Full Text Available Community involvement in mosquito management programs provides more sustainable and effective organization and service. A door to door survey in Wayne County, NC carried out by student volunteers, resulted in 60 household responses. Residents had not previously experienced outreach from the county (88%, and 95% of them thought the student door to door survey was an effective form of outreach. One third of the residents thought mosquitoes were severe where they lived, but only 9% thought they had any containers in their yard that might breed mosquitoes. Only 15% of the residents were concerned about mosquito borne diseases. These responses provide evidence that outreach and education on mosquito control and diseases were necessary steps for future mosquito control community planning.

Timothy Kelley

2009-07-01

66

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)

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.

Antônio L. Ruas-Neto

1994-06-01

67

Aerial and Tidal Transport of Mosquito Control Pesticides into the Florida Keys National Marine Sanctuary  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Para determinar si los adulticidas de mosquitos,aplicados en los Cayos de la Florida,causan efectos ecológicos adversos en el Santuario Marino Nacional de los Cayos de la Florida,se monitoreó la distribución y persistencia de dos adulticidas de mosquitos.Estos fueron permetrina y dibrom (naled).Se t [...] rabajó durante tres aplicaciones rutinarias hechas por la Unidad de Control de Mosquitos de los Cayos de la Florida.La finalidad era determinar si concentraciones tóxicas de los plaguicidas llegaban al santuario por transporte aéreo o por las corrientes de marea.La cantidad de plaguicida que entra por vía aérea fue monitoreada utilizando filtros de fibra de vidrio,montados en flotadores dispuestos sistemáticamente a ambos lados del FKNMS. La Permetrina fue recuperada en filtros a sotavento del santuario durante tres aplicaciones,con un ámbito entre 0.5 y 50.1 µg/m² durante todo el estudio.El transporte por corrientes de marea fue monitoreado recolectando muestras de agua superficiales y subsuperficiales en puntos definidos.Se notó el transporte por mareas de naled y diclorvos (producto degradado de naled)en aguas adyacentes al santuario.Estos compuestos fueron detectados en muestras subsuperficiales en aguas fuera de la costa con concentraciones de 0.1 a 0.6 µg/l,14 hr después de la aplicación.La Permetrina no fue detectada en muestras de agua fuera de la costa;sin embargo,hubo concentraciones de 5.1 a 9.4 µg/l en aguas superficiales del sistema de canales adyacente a la ruta de aplicación. Comparaciones de las concentraciones observadas con información toxicológica (permetrina LC-50,96 hr para Mysidopsis bahia =0.02 µg/l)indican un peligro potencial para invertebrados marinos en los canales y la posibilidad de transporte por mareas a otras áreas. Abstract in english 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 persistence of two mosquito adulticides,pe [...] rmethrin 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 µg/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 µg/l,14 hr after application.Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 µg/l were found in surface water from the canal system adjacent to the application route.Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50,96 hr for Mysidopsis bahia =0.02 µg/l)indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas.

R.H, Pierce; M.S, Henry; T.C, Blum; E.M, Mueller.

2005-05-01

68

Aerial and Tidal Transport of Mosquito Control Pesticides into the Florida Keys National Marine Sanctuary  

Directory of Open Access Journals (Sweden)

Full Text Available 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 persistence 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 µg/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 productwas apparent in the adjacent waters of the FKNMS.These compounds were detected in subsurface,offshore water at 0.1 to 0.6 µg/l,14 hr after application.Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 µg/l were found in surface water from the canal system adjacent to the application route.Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50,96 hr for Mysidopsis bahia =0.02 µg/lindicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas.Para determinar si los adulticidas de mosquitos,aplicados en los Cayos de la Florida,causan efectos ecológicos adversos en el Santuario Marino Nacional de los Cayos de la Florida,se monitoreó la distribución y persistencia de dos adulticidas de mosquitos.Estos fueron permetrina y dibrom (naled.Se trabajó durante tres aplicaciones rutinarias hechas por la Unidad de Control de Mosquitos de los Cayos de la Florida.La finalidad era determinar si concentraciones tóxicas de los plaguicidas llegaban al santuario por transporte aéreo o por las corrientes de marea.La cantidad de plaguicida que entra por vía aérea fue monitoreada utilizando filtros de fibra de vidrio,montados en flotadores dispuestos sistemáticamente a ambos lados del FKNMS. La Permetrina fue recuperada en filtros a sotavento del santuario durante tres aplicaciones,con un ámbito entre 0.5 y 50.1 µg/m² durante todo el estudio.El transporte por corrientes de marea fue monitoreado recolectando muestras de agua superficiales y subsuperficiales en puntos definidos.Se notó el transporte por mareas de naled y diclorvos (producto degradado de naleden aguas adyacentes al santuario.Estos compuestos fueron detectados en muestras subsuperficiales en aguas fuera de la costa con concentraciones de 0.1 a 0.6 µg/l,14 hr después de la aplicación.La Permetrina no fue detectada en muestras de agua fuera de la costa;sin embargo,hubo concentraciones de 5.1 a 9.4 µg/l en aguas superficiales del sistema de canales adyacente a la ruta de aplicación. Comparaciones de las concentraciones observadas con información toxicológica (permetrina LC-50,96 hr para Mysidopsis bahia =0.02 µg/lindican un peligro potencial para invertebrados marinos en los canales y la posibilidad de transporte por mareas a otras áreas.

R.H Pierce

2005-05-01

69

The Importance of Age Dependent Mortality and the Extrinsic Incubation Period in Models of Mosquito-Borne Disease Transmission and Control  

OpenAIRE

Nearly all mathematical models of vector-borne diseases have assumed that vectors die at constant rates. However, recent empirical research suggests that mosquito mortality rates are frequently age dependent. This work develops a simple mathematical model to assess how relaxing the classical assumption of constant mortality affects the predicted effectiveness of anti-vectorial interventions. The effectiveness of mosquito control when mosquitoes die at age dependent rates was also compared acr...

Bellan, Steve E.

2010-01-01

70

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

71

Achieving high coverage of larval-stage mosquito surveillance: challenges for a community-based mosquito control programme in urban Dar es Salaam, Tanzania  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP in urban Dar es Salaam, Tanzania. Methods Cross-sectional surveys were carried out to assess the ability of community-owned resource persons (CORPs to detect mosquito breeding sites and larvae in areas with and without larviciding. Potential environmental and programmatic determinants of habitat detection coverage and detection sensitivity of mosquito larvae were recorded during guided walks with 64 different CORPs to assess the accuracy of data each had collected the previous day. Results CORPs reported the presence of 66.2% of all aquatic habitats (1,963/2,965, but only detected Anopheles larvae in 12.6% (29/230 of habitats that contained them. Detection sensitivity was particularly low for late-stage Anopheles (2.7%, 3/111, the most direct programmatic indicator of malaria vector productivity. Whether a CORP found a wet habitat or not was associated with his/her unfamiliarity with the area (Odds Ratio (OR [95% confidence interval (CI] = 0.16 [0.130, 0.203], P Conclusions Accessibility of habitats in urban settings presents a major challenge because the majority of compounds are fenced for security reasons. Furthermore, CORPs under-reported larvae especially where larvicides were applied. This UMCP system for larval surveillance in cities must be urgently revised to improve access to enclosed compounds and the sensitivity with which habitats are searched for larvae.

Shoo Bryson

2009-12-01

72

O aproveitamento do resíduo da indústria do sisal no controle de larvas de mosquitos / Utilization of the waste of sisal industry in the control of mosquito larvae  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 pa [...] ra 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. Abstract in english The aim of this research was to utilize the waste residues of sisal fiber separation from Agave sisalana leaves to develop a larvicide for the combat of mosquito transmitting tropical diseases. Larvae of Aedes aegypti and Culex quinquefasciatus were exposed to different concentrations of the Agave e [...] xtract for 24 hours to determine lethal concentrations. The LC50 for A. aegypti was 322 ppm and the LC50 for C. quinquefasciatus was 183 ppm. To detect the active substances, saponins were investigated. It was found that the various components of the extract were effective in eliminating the larvae. Under field conditions, this formulation can probably be used at 100 ppm, wich causes 100% mortality of C. quinquefasciatus larvae after 3-4 days. The product is not recommended for use against A. aegypti due to the necessity for high concentrations and to the fact that the larvae of this species live frequently on drinking water. To avoid fermentation, Agave extract should be used in a dehydrated form which also represent a good formulation for practical use.

Ana Paula B., Pizarro; Alfredo M., Oliveira Filho; José P., Parente; Marli T.V., Melo; Celso E. dos, Santos; Paulo R., Lima.

1999-02-01

73

O aproveitamento do resíduo da indústria do sisal no controle de larvas de mosquitos Utilization of the waste of sisal industry in the control of mosquito larvae  

Directory of Open Access Journals (Sweden)

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.The aim of this research was to utilize the waste residues of sisal fiber separation from Agave sisalana leaves to develop a larvicide for the combat of mosquito transmitting tropical diseases. Larvae of Aedes aegypti and Culex quinquefasciatus were exposed to different concentrations of the Agave extract for 24 hours to determine lethal concentrations. The LC50 for A. aegypti was 322 ppm and the LC50 for C. quinquefasciatus was 183 ppm. To detect the active substances, saponins were investigated. It was found that the various components of the extract were effective in eliminating the larvae. Under field conditions, this formulation can probably be used at 100 ppm, wich causes 100% mortality of C. quinquefasciatus larvae after 3-4 days. The product is not recommended for use against A. aegypti due to the necessity for high concentrations and to the fact that the larvae of this species live frequently on drinking water. To avoid fermentation, Agave extract should be used in a dehydrated form which also represent a good formulation for practical use.

Ana Paula B. Pizarro

1999-02-01

74

Biorational insecticides for control of mosquitoes and black flies in Sinaloa  

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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.

Cipriano García Gutiérrez

2012-09-01

75

Maternal Germline-Specific Genes in the Asian Malaria Mosquito Anopheles stephensi: Characterization and Application for Disease Control.  

Science.gov (United States)

Anopheles stephensi is a principal vector of urban malaria on the Indian subcontinent and an emerging model for molecular and genetic studies of mosquito biology. To enhance our understanding of female mosquito reproduction, and to develop new tools for basic research and for genetic strategies to control mosquito-borne infectious diseases, we identified 79 genes that displayed previtellogenic germline-specific expression based on RNA-Seq data generated from 11 life stage- and sex-specific samples. Analysis of this gene set provided insights into the biology and evolution of female reproduction. Promoters from two of these candidates, vitellogenin receptor and nanos, were used in independent transgenic cassettes for the expression of artificial microRNAs against suspected mosquito maternal-effect genes, discontinuous actin hexagon and myd88. We show these promoters have early germline-specific expression, and demonstrate 73% and 42% knockdown of myd88 and discontinuous actin hexagon mRNA in 48 hr post-bloodmeal ovaries, respectively. Additionally, we demonstrate maternal-specific delivery of mRNA and protein to progeny embryos. We discuss the application of this system of maternal delivery of mRNA/miRNA/protein in research on mosquito reproduction and embryonic development, and for the development of a gene drive system based on maternal-effect dominant embryonic arrest. PMID:25480960

Biedler, James K; Qi, Yumin; Pledger, David; James, Anthony; Tu, Zhijian

2014-12-01

76

Review of semiochemicals that mediate the oviposition of mosquitoes: a possible sustainable tool for the control and monitoring of Culicidae / Revisão dos semioquímicos que mediam a oviposição em mosquitos: uma possível ferramenta sustentável para o monitoramento e controle de Culicidae  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A seleção de locais adequados pelas fêmeas de mosquitos para depositarem seus ovos é um fator chave para a sobrevivência de seus imaturos (ovos e larvas). O conhecimento das relações ecológicas implicadas neste processo é de grande importância quando se refere a vetores de agentes patogênicos. A det [...] erminação do local de oviposição pelas fêmeas grávidas envolve uma rede de mensagens químicas, visuais, olfativas e táteis que facilitam a localização de lugares adequados para depositarem seus ovos. Neste trabalho é apresentada uma revisão bibliográfica dos principais aspectos relacionados com semioquímicos presentes na oviposição dos mosquitos auxiliando no entendimento dos mecanismos de atuação dos mesmos e potencializando a aplicação destes semioquímicos como uma possível ferramenta de monitoramento e controle de Culicidae. Abstract in english The choice for suitable places for female mosquitoes to lay eggs is a key-factor for the survival of immature stages (eggs and larvae). This knowledge stands out in importance concerning the control of disease vectors. The selection of a place for oviposition requires a set of chemical, visual, olfa [...] ctory and tactile cues that interact with the female before laying eggs, helping the localization of adequate sites for oviposition. The present paper presents a bibliographic revision on the main aspects of semiochemicals in regard to mosquitoes' oviposition, aiding the comprehension of their mechanisms and estimation of their potential as a tool for the monitoring and control of the Culicidae.

Mario A., Navarro-Silva; Francisco A., Marques; Jonny E., Duque L.

77

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...

78

Economic evaluation of an area-wide integrated pest management program to control the Asian tiger mosquito in New Jersey  

Science.gov (United States)

Aedes albopictus is the most invasive mosquito in the world, an important disease vector, and a biting nuisance that limits outdoor activities. Area-wide integrated pest management (AW-IPM) is the recommended control strategy. We conducted an economic evaluation of the AW-IPM project in Mercer and ...

79

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

OpenAIRE

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 ...

Worrall Eve; Fillinger Ulrike

2011-01-01

80

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

Science.gov (United States)

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

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

2014-04-01

81

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

Science.gov (United States)

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

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

2013-09-01

82

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

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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

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

2007-04-01

83

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  

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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.

Adrias Araceli Q

2010-05-01

84

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

Science.gov (United States)

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

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

85

O aproveitamento do resíduo da indústria do sisal no controle de larvas de mosquitos Utilization of the waste of sisal industry in the control of mosquito larvae  

OpenAIRE

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, ficand...

Pizarro, Ana Paula B.; Oliveira Filho, Alfredo M.; Parente, Jose? P.; Melo, Marli T. V.; Dos Santos, Celso E.; Lima, Paulo R.

1999-01-01

86

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

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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.

Márcia Aparecida Sperança

2007-06-01

87

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

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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.

Jean Popovici

2010-12-01

88

Comparison of deltamethrin as indoor residual spray or on insecticide treated nets for mosquito control in Lake Chilwa  

OpenAIRE

We conducted a study on the control of mosquitos on Chisi Island in Lake Chilwa from August to November, 2006. The aim was to compare the cost and efficacy of deltamethrin, a pyrethroid based insecticide, when used in insecticide treated nets (ITN) and when used in indoor residual spray (IRS). Thirty village huts were enrolled in the study. Fifteen were systematically selected in a stratified manner and sprayed with deltamethrin following manufacturers' standard application procedures of 0.02...

Pemba, Dylo F.; Bandason, Elizabeth; Namangale, Jimmy

2008-01-01

89

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

OpenAIRE

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 withdrawn 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-Augus...

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

2008-01-01

90

Distribution of Bacillus thuringiensis subsp. israelensis in Soil of a Swiss Wetland Reserve after 22 Years of Mosquito Control?†  

OpenAIRE

Recurrent treatments with Bacillus thuringiensis subsp. israelensis are required to control the floodwater mosquito Aedes vexans that breeds in large numbers in the wetlands of the Bolle di Magadino Reserve in Canton Ticino, Switzerland. Interventions have been carried out since 1988. In the present study, the spatial distribution of resting B. thuringiensis subsp. israelensis spores in the soil was measured. The B. thuringiensis subsp. israelensis concentration was determined in soil samples...

Guidi, Valeria; Patocchi, Nicola; Lu?thy, Peter; Tonolla, Mauro

2011-01-01

91

Review: Improving our knowledge of male mosquito biology in relation to genetic control programmes.  

Science.gov (United States)

The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites or larviciding with insecticides thereof. However, these methods are under threat from, amongst other issues, the development of insecticide resistance and the practical difficulty of maintaining long-term community-wide efforts. The sterile insect technique (SIT), whose success hinges on having a good understanding of the biology and behaviour of the male mosquito, is an additional weapon in the limited arsenal against mosquito vectors. The successful production and release of sterile males, which is the mechanism of population suppression by SIT, relies on the release of mass-reared sterile males able to confer sterility in the target population by mating with wild females. A five year Joint FAO/IAEA Coordinated Research Project brought together researchers from around the world to investigate the pre-mating conditions of male mosquitoes (physiology and behaviour, resource acquisition and allocation, and dispersal), the mosquito mating systems and the contribution of molecular or chemical approaches to the understanding of male mosquito mating behaviour. A summary of the existing knowledge and the main novel findings of this group is reviewed here, and further presented in the reviews and research articles that form this Acta Tropica special issue. PMID:24252487

Lees, Rosemary Susan; Knols, Bart; Bellini, Romeo; Benedict, Mark Q; Bheecarry, Ambicadutt; Bossin, Hervé Christophe; Chadee, Dave D; Charlwood, Jacques; Dabiré, Roch K; Djogbenou, Luc; Egyir-Yawson, Alexander; Gato, René; Gouagna, Louis Clément; Hassan, Mo'awia Mukhtar; Khan, Shakil Ahmed; Koekemoer, Lizette L; Lemperiere, Guy; Manoukis, Nicholas C; Mozuraitis, Raimondas; Pitts, R Jason; Simard, Frederic; Gilles, Jeremie R L

2014-04-01

92

Pitch control of multi-channel graded-index core polymer waveguide for optical PCB using the Mosquito method  

Science.gov (United States)

We successfully fabricate multi-channel GI circular-core polymer waveguides with precisely controlled pitches utilizing the Mosquito method. The Mosquito method is a very simple method for fabricating GI-core polymer optical waveguides that utilizes a micro dispenser. In this method, a viscous core monomer is directly dispensed into a cladding monomer layer before UV cured, and circular cores are formed by curing both the core and cladding under a UV exposure. Here, it is a concern that a needle position accuracy influences on the interchannel pitch when parallel cores are fabricated by parallel repetitive scan of a single needle. However, we succeeded in controlling the pitch with the Mosquito method and then, GI-core waveguides with 250.7+/-5.2 ?m, 126.7+/-2.6 ?m and 61.7+/-3.4 ?m are successfully fabricated for the pre-set values of 250 ?m, 125 ?m and 62.5 ?m, respectively. Then, we demonstrate a 4 × 10 Gbps transmission over the fabricated GI-core waveguide by connecting the waveguide to an MMF ribbon with a 250-?m pitch, which is realized because the pitch of the fabricated waveguide is accurately controlled to 250 ?m.

Kinoshita, Ryota; Suganuma, Daisuke; Ishigure, Takaaki

2014-03-01

93

Eficiencia del extracto de Ricinus communis para el control del mosquito Culex  

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Full Text Available Este artículo evaluó el efecto insecticida del extracto de Ricinus communis sobre larvas de mosquitos Culex. A las 24 h la mortalidad es de 8.33 % con dosis de 1 mL del extracto en una concentración de 500 ppm; 35 % en dosis de 1 mL de una concentración de 1000 ppm; 65 % en dosis de 5 mL de una concentración de 1000 ppm; 98.33 % con 10 mL en concentración de 1000 ppm; testigos 3.3 %. Cuando se evaluó el efecto insecticida del extracto aplicado por aspersión en concentraciones de 500, 750 y 1000 ppm, se consiguieron mortalidades de 18.33, 36.66 y 48.32 %, respectivamente. Ninguna de las concentraciones evaluadas alcanzó el cien por ciento de letalidad. En la prueba de semicampo, solo se logró una mortalidad de 9 %. Se evidenció que el extracto tiene un mejor efecto insecticida para el control de ejemplares inmaduros en estado larvario que sobre los adultos.

Diego Tomás Corradine Mora

2014-05-01

94

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

Science.gov (United States)

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.

Bargar, Timothy A.

2012-01-01

95

Two mosquito LRR proteins function as complement control factors in the TEP1-mediated killing of Plasmodium.  

Science.gov (United States)

Plasmodium development within Anopheles mosquitoes is a vulnerable step in the parasite transmission cycle, and targeting this step represents a promising strategy for malaria control. The thioester-containing complement-like protein TEP1 and two leucine-rich repeat (LRR) proteins, LRIM1 and APL1, have been identified as major mosquito factors that regulate parasite loads. Here, we show that LRIM1 and APL1 are required for binding of TEP1 to parasites. RNAi silencing of the LRR-encoding genes results in deposition of TEP1 on Anopheles tissues, thereby depleting TEP1 from circulation in the hemolymph and impeding its binding to Plasmodium. LRIM1 and APL1 not only stabilize circulating TEP1, they also stabilize each other prior to their interaction with TEP1. Our results indicate that three major antiparasitic factors in mosquitoes jointly function as a complement-like system in parasite killing, and they reveal a role for LRR proteins as complement control factors. PMID:19286136

Fraiture, Malou; Baxter, Richard H G; Steinert, Stefanie; Chelliah, Yogarany; Frolet, Cécile; Quispe-Tintaya, Wilber; Hoffmann, Jules A; Blandin, Stéphanie A; Levashina, Elena A

2009-03-19

96

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

97

Indoor Use of Plastic Sheeting Impregnated with Carbamate Combined with Long-Lasting Insecticidal Mosquito Nets for the Control of Pyrethroid-Resistant Malaria Vectors  

OpenAIRE

The combined efficacy of a long-lasting insecticidal net (LLIN) and a carbamate-treated plastic sheeting (CTPS) or indoor residual spraying (IRS) for control of insecticide-resistant mosquitoes was evaluated in experimental huts in Burkina Faso. Anopheles gambiae from the area is resistant to pyrethroids and to a lesser extent, carbamates. Relatively low mortality rates were observed with the LLIN (44%), IRS (42%), and CTPS (52%), whereas both combinations killed significantly more mosquitoes...

Dje?nontin, Armel; Chandre, Fabrice; Dabire?, K. Roch; Chabi, Joseph; N Guessan, Raphael; Baldet, Thierry; Akogbe?to, Martin; Corbel, Vincent

2010-01-01

98

Laboratory evaluation techniques to investigate the spatial potential of repellents for push and pull mosquito control systems.  

Science.gov (United States)

A protocol has been developed for the indoor evaluation of candidate spatial repellents intended for use in push and pull systems. Single treatments (catnip oil, 1-methylpiperazine, and homopiperazine) and a mixture of catnip oil and homopiperazine were tested with yellow-fever mosquitoes (Aedes aegypti) in Y-tube olfactometers to determine 1) if these compounds inhibited mosquito host-seeking at short distances and 2) if results obtained in olfactometer tests can be correlated with a larger scale set-up, that is, a room test. All test materials significantly decreased the ability of mosquitoes to find host odors (from a human finger) by up to 96.7% (2.5% catnip and homopiperazine mix). Similar effects could be observed within a new room test set-up, which involved a repellent dispensing system and an attractive trap (BG-Sentinel). Mosquitoes captured by the BGS trap had to fly through a treatment-containing air curtain created by the dispensing system. Compared with the use of a control (ethanol solvent without candidate repellent), trap catch rates were significantly reduced when 5% catnip, 5% 1-methylpiperazine, and 5% homopiperazine were dispensed. Homopiperazine produced the greatest level of host-seeking inhibition with a 95% reduction in the trap catches. The experimental set-up was modified to test the viability of those technologies in a simple push & pull situation.. The combination of BGS trap and a 10% mix of catnip and homopiperazine helped to reduce human landing rates by up to 44.2% with a volunteer sitting behind the air curtain and the trap running in front of the curtain. PMID:23270167

Obermayr, U; Ruther, J; Bernier, U; Rose, A; Geier, M

2012-11-01

99

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)

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.

Knols Bart GJ

2002-06-01

100

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)

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.

Roger Eritja

2012-12-01

101

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...

102

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

Science.gov (United States)

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

103

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

Directory of Open Access Journals (Sweden)

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.

Takken Willem

2011-02-01

104

Comparison between diflubenzuron and a Bacillus thuringiensis israelensis- and Lysinibacillus sphaericus-based formulation for the control of mosquito larvae in urban catch basins in Switzerland.  

Science.gov (United States)

A field test was conducted to evaluate a commercial biolarvicide based on Bacillus thuringiensis var. israelensis and Lysinibacillus sphaericus to control mosquitoes breeding in catch basins in southern Switzerland. The efficacy and residual activity of the microbial mosquito larvicide applied at the recommended rate of 10 g per catch basin was compared to the currently used larvicide diflubenzuron. Both products provided a very good control activity (> 97% of reduction) of late instars (3rd and 4th instars) and pupae for 4 wk. However, only the microbial formulation controlled immature stages during the whole period of the trial, with > 98% of larval reduction. A single application of the microbial larvicide applied at 10 g per catch basin significantly reduced the number of immature mosquitoes for at least 70 days. The quantity of rainfall in the 48-h period before each sampling and the water temperature did not influence the efficacy of the treatments. Under the environmental conditions encountered in southern Switzerland, the larvicide tested may be a valid alternative to diflubenzuron to control mosquitoes in urban catch basins. The long-lasting control by the microbial larvicide further reduces the number of treatments required to keep the population of mosquitoes at low levels. PMID:23923328

Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro

2013-06-01

105

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  

OpenAIRE

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 b...

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

2008-01-01

106

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.

107

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

OpenAIRE

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, ficand...

Pizarro Ana Paula B.; Oliveira Filho Alfredo M.; Parente José P.; Melo Marli T. V.; Dos, Santos Celso E.; Lima Paulo R.

1999-01-01

108

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

OpenAIRE

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...

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

2009-01-01

109

Mosquito repellents in frog skin.  

Science.gov (United States)

The search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (DEET). Given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. We investigated frog skin secretions to confirm the existence of mosquito repellent properties. Litoria caerulea secretions were assessed for mosquito repellency by topical application on mice. The secretions provided protection against host-seeking Culex annulirostris mosquitoes. Olfactometer tests using aqueous washes of skin secretions from L. caerulea and four other frog species were conducted to determine whether volatile components were responsible for repellency. Volatiles from Litoria rubella and Uperoleia mjobergi secretions were repellent to C. annulirostris, albeit not as repellent as a DEET control. The demonstration of endogenous insect repellents in amphibians is novel, and demonstrates that many aspects of frog chemical ecology remain unexplored. PMID:17148373

Williams, C R; Smith, B P C; Best, S M; Tyler, M J

2006-06-22

110

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

Science.gov (United States)

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

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

2014-06-01

111

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)

112

Eficiencia del extracto de Ricinus communis para el control del mosquito Culex  

OpenAIRE

Este artículo evaluó el efecto insecticida del extracto de Ricinus communis sobre larvas de mosquitos Culex. A las 24 h la mortalidad es de 8.33 % con dosis de 1 mL del extracto en una concentración de 500 ppm; 35 % en dosis de 1 mL de una concentración de 1000 ppm; 65 % en dosis de 5 mL de una concentración de 1000 ppm; 98.33 % con 10 mL en concentración de 1000 ppm; testigos 3.3 %. Cuando se evaluó el efecto insecticida del extracto aplicado por aspersión en concentraciones de 500, ...

Diego Tomás Corradine Mora; Ingrid Maritza Beltrán Sastoque; Yurani Corredor Páramo; Diana Carolina Moreno Aguilera

2014-01-01

113

Quantitative trait loci that control vector competence for dengue-2 virus in the mosquito Aedes aegypti.  

OpenAIRE

Quantitative trait loci (QTL) affecting the ability of the mosquito Aedes aegypti to become infected with dengue-2 virus were mapped in an F(1) intercross. Dengue-susceptible A. aegypti aegypti were crossed with dengue refractory A. aegypti formosus. F(2) offspring were analyzed for midgut infection and escape barriers. In P(1) and F(1) parents and in 207 F(2) individuals, regions of 14 cDNA loci were analyzed with single-strand conformation polymorphism analysis to identify and orient linkag...

Bosio, C. F.; Fulton, R. E.; Salasek, M. L.; Beaty, B. J.; Black, W. C.

2000-01-01

114

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)

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.

Jonny E. Duque L.

2004-04-01

115

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2008-03-01

116

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

Science.gov (United States)

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 withdrawn 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. PMID:18392548

Jambulingam, P; Gunasekaran, K; Sahu, Ss; Vijayakumar, T

2008-03-01

117

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

Directory of Open Access Journals (Sweden)

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 withdrawn 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.

P Jambulingam

2008-03-01

118

Mosquito age and dengue transmission  

Science.gov (United States)

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.

The Grand Challenges in Global Health Initiative

119

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

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 ...

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

2010-01-01

120

Characterizing the Aedes aegypti Population in a Vietnamese Village in Preparation for a Wolbachia-Based Mosquito Control Strategy to Eliminate Dengue  

OpenAIRE

Prevention of dengue disease relies predominantly on controlling the mosquito Aedes aegypti. A new control strategy is being developed based on the use of a life-shortening strain of the intracellular bacteria Wolbachia, which has been microinjected into Ae. aegypti in the laboratory. This strategy aims to eliminate the older and epidemiologically significant individuals from Ae. aegypti populations and thus eliminate dengue transmission. However, designing an intervention strategy involving ...

Jeffery, Jason A. L.; Thi Yen, Nguyen; Nam, Vu Sinh; Nghia, Le Trung; Hoffmann, Ary A.; Kay, Brian H.; Ryan, Peter A.

2009-01-01

121

Wolbachia-a foe for mosquitoes  

OpenAIRE

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...

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

2014-01-01

122

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

Directory of Open Access Journals (Sweden)

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.

Worrall Eve

2011-11-01

123

[Utilization of the waste of sisal industry in the control of mosquito larvae].  

Science.gov (United States)

The aim of this research was to utilize the waste residues of sisal fiber separation from Agave sisalana leaves to develop a larvicide for the combat of mosquito transmitting tropical diseases. Larvae of Aedes aegypti and Culex quinquefasciatus were exposed to different concentrations of the Agave extract for 24 hours to determine lethal concentrations. The LC50 for A. aegypti was 322 ppm and the LC50 for C. quinquefasciatus was 183 ppm. To detect the active substances, saponins were investigated. It was found that the various components of the extract were effective in eliminating the larvae. Under field conditions, this formulation can probably be used at 100 ppm, which causes 100% mortality of C. quinquefasciatus larvae after 3-4 days. The product is not recommended for use against A. aegypti due to the necessity for high concentrations and to the fact that the larvae of this species live frequently on drinking water. To avoid fermentation, Agave extract should be used in a dehydrated form which also represent a good formulation for practical use. PMID:9927821

Pizarro, A P; Oliveira Filho, A M; Parente, J P; Melo, M T; dos Santos, C E; Lima, P R

1999-01-01

124

Chemical odorant of colonial seabird repels mosquitoes.  

Science.gov (United States)

The crested auklet, Aethia cristatella, emits a class of aldehydes shown to be potent invertebrate repellents when used by heteropterans against their predators. Our aim was to determine the efficacy of these aldehydes against mosquitoes in the laboratory. Synthetic analogues of the auklet odorant were strongly repellent to mosquitoes in controlled laboratory trials. Furthermore, the efficacy was similar to previous reports for commercial mosquito repellents. These results, in combination with a previously published study, show that constituents of the aldehyde odorant are broad spectrum in efficacy against ectoparasitic arthropods of birds. Our report is the first empirical evidence for an endogenous mosquito repellent in birds. PMID:16119555

Douglas, H D; Co, J E; Jones, T H; Conner, W E; Day, J F

2005-07-01

125

The practical importance of permanent and semipermanent habitats for controlling aquatic stages of Anopheles gambiae sensu lato mosquitoes: operational observations from a rural town in western Kenya  

OpenAIRE

Control of aquatic-stage Anopheles is one of the oldest and most historically successful interventions to prevent malaria, but it has seen little application in Africa. Consequently, the ecology of immature afrotropical Anopheles has received insufficient attention. We therefore examined the population dynamics of African anopheline and culicine mosquitoes using operationally practicable techniques to examine the relative importance and availability of different larval habitats in an area of ...

Fillinger, U.; Sonye, G.; Killeen, G. F.; Knols, B. G. J.; Becker, N.

2004-01-01

126

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

OpenAIRE

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 ...

Reddy Vamsi P; Abaga Simon; Overgaard Hans J; Reddy Michael R; Caccone Adalgisa; Kiszewski Anthony E; Slotman Michel A

2011-01-01

127

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

OpenAIRE

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.

Klowden, M. J.; Bulla, L. A.

1984-01-01

128

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

Science.gov (United States)

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

Ramanibai, R; Velayutham, K

2015-02-01

129

Distribution of Bacillus thuringiensis subsp. israelensis in Soil of a Swiss Wetland Reserve after 22 Years of Mosquito Control?†  

Science.gov (United States)

Recurrent treatments with Bacillus thuringiensis subsp. israelensis are required to control the floodwater mosquito Aedes vexans that breeds in large numbers in the wetlands of the Bolle di Magadino Reserve in Canton Ticino, Switzerland. Interventions have been carried out since 1988. In the present study, the spatial distribution of resting B. thuringiensis subsp. israelensis spores in the soil was measured. The B. thuringiensis subsp. israelensis concentration was determined in soil samples collected along six transects covering different elevations within the periodically flooded zones. A total of 258 samples were processed and analyzed by quantitative PCR that targeted an identical fragment of 159 bp for the B. thuringiensis subsp. israelensis cry4Aa and cry4Ba genes. B. thuringiensis subsp. israelensis spores were found to persist in soils of the wetland reserve at concentrations of up to 6.8 log per gram of soil. Continuous accumulation due to regular treatments could be excluded, as the decrease in spores amounted to 95.8% (95% confidence interval, 93.9 to 97.7%). The distribution of spores was correlated to the number of B. thuringiensis subsp. israelensis treatments, the elevation of the sampling point, and the duration of the flooding periods. The number of B. thuringiensis subsp. israelensis treatments was the major factor influencing the distribution of spores in the different topographic zones (P < 0.0001). These findings indicated that B. thuringiensis subsp. israelensis spores are rather immobile after their introduction into the environment. PMID:21498758

Guidi, Valeria; Patocchi, Nicola; Lüthy, Peter; Tonolla, Mauro

2011-01-01

130

A tool box for operational mosquito larval control: preliminary results and early lessons from the Urban Malaria Control Programme in Dar es Salaam, Tanzania  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background As the population of Africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed. Methods A recently initiated Urban Malaria Control Programme in Dar es Salaam delegates responsibility for routine mosquito control and surveillance to modestly-paid community members, known as Community-Owned Resource Persons (CORPs. New vector surveillance, larviciding and management systems were designed and evaluated in 15 city wards to allow timely collection, interpretation and reaction to entomologic monitoring data using practical procedures that rely on minimal technology. After one year of baseline data collection, operational larviciding with Bacillus thuringiensis var. israelensis commenced in March 2006 in three selected wards. Results The procedures and staff management systems described greatly improved standards of larval surveillance relative to that reported at the outset of this programme. In the first year of the programme, over 65,000 potential Anopheles habitats were surveyed by 90 CORPs on a weekly basis. Reaction times to vector surveillance at observations were one day, week and month at ward, municipal and city levels, respectively. One year of community-based larviciding reduced transmission by the primary malaria vector, Anopheles gambiae s.l., by 31% (95% C.I. = 21.6–37.6%; p = 0.04. Conclusion This novel management, monitoring and evaluation system for implementing routine larviciding of malaria vectors in African cities has shown considerable potential for sustained, rapidly responsive, data-driven and affordable application. Nevertheless, the true programmatic value of larviciding in urban Africa can only be established through longer-term programmes which are stably financed and allow the operational teams and management infrastructures to mature by learning from experience.

Govella Nico J

2008-01-01

131

Tick, fly, and mosquito control; lessons from the past, solutions for the future  

OpenAIRE

In order to continue to produce livestock in a sustainable fashion, it is suggested that what was used in the past will continue to form the mainstay of future control. For the foreseeable future, we must conserve what we have, and use it in combination with all the principles of integrated pest management, namely strategic and focussed treatments of animals, environmental control of breeding sites, disease management (including the principles of enzootic stability), and resistant breeds. Whi...

Peter, R. J.; Den Bossche, P.; Penzhorn, B. L.; Sharp, B.

2005-01-01

132

Tick, fly, and mosquito control : lessons from the past, solutions for the future  

OpenAIRE

In order to continue to produce livestock in a sustainable fashion, it is suggested that what was used in the past will continue to form the mainstay of future control. For the foreseeable future, we must conserve what we have, and use it in combination with all the principles of integrated pest management, namely strategic and focussed treatments of animals, environmental control of breeding sites, disease management (including the principles of enzootic stability), and resistant breeds. Whi...

Peter, R. J.; Den Bossche, Peter; Penzhorn, Barend Louis; Sharp, B.

2005-01-01

133

Influence of climate change on mosquito development and mosquito-borne diseases in Europe.  

Science.gov (United States)

Mass occurrence of mosquitoes can have an immense impact on the quality of life in areas such as the Upper Rhine Valley. Therefore, biological and environmental measures are applied to prevent mass development in many regions of Europe. Despite successful prevention measures, the risk of contracting mosquito-borne viral diseases, such as West Nile fever, should be discounted in Central Europe. The transport of mosquitoes (e.g., through tire trade or within containers) into Germany has to be prevented. Individuals (tourists and immigrants) infected with imported vector-borne pathogens and parasites must be diagnosed and treated immediately. Mosquitoes and mosquito-borne diseases know no borders, and their spread is also a consequence of high mobility and globalization. Therefore, mosquito control requires international cooperation. People's increased mobility and international trade play a more important role in the dissemination of the vectors and their pathogens/parasites than increasing temperatures. PMID:19030883

Becker, Norbert

2008-12-01

134

Phagocytosis in mosquito immune responses.  

Science.gov (United States)

Anopheles mosquitoes are the only vectors of human malaria parasites. Mosquito-parasite interactions are critical for disease transmission and therefore are a potential target for malaria control strategies. Mosquitoes mount potent immune responses that efficiently limit proliferation of a variety of infectious agents, including microbial pathogens and malaria parasites. The recent completion of the Anopheles gambiae genome sequencing project combined with the development of the powerful RNA interference-based gene silencing helped to identify major players of the immune defenses and uncovered evolutionarily conserved mechanisms in the anti-bacterial and anti-Plasmodium responses. The anti-bacterial responses are based on phagocytosis at early steps of infections, followed, several hours later, by the synthesis of anti-microbial peptides. The principal regulators of anti-parasitic responses are predominantly synthesized by the mosquito blood cells; however, the exact molecular mechanisms of parasite killing remain unclear. Several regulators of phagocytosis are also required for efficient parasite killing. Here, we summarize our current knowledge of the anti-bacterial and anti-parasitic responses, with the particular emphasis on the role of phagocytosis in mosquito immunity. PMID:17850478

Blandin, Stephanie A; Levashina, Elena A

2007-10-01

135

Virtual mosquito  

Science.gov (United States)

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

0002-11-30

136

Mosquito coil emissions and health implications.  

Science.gov (United States)

Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes. PMID:12948883

Liu, Weili; Zhang, Junfeng; Hashim, Jamal H; Jalaludin, Juliana; Hashim, Zailina; Goldstein, Bernard D

2003-09-01

137

Tick, fly, and mosquito control--lessons from the past, solutions for the future.  

Science.gov (United States)

In order to continue to produce livestock in a sustainable fashion, it is suggested that what was used in the past will continue to form the mainstay of future control. For the foreseeable future, we must conserve what we have, and use it in combination with all the principles of integrated pest management, namely strategic and focussed treatments of animals, environmental control of breeding sites, disease management (including the principles of enzootic stability), and resistant breeds. Whilst new technologies, such as the development of vaccines both against the insect pest in some cases or the disease they transmit in others, and genetic engineering hold out some hope for the future; these are not sufficiently well advanced to permit wholesale application. PMID:16099104

Peter, R J; Van den Bossche, P; Penzhorn, B L; Sharp, B

2005-09-30

138

Urban Agriculture and Operational Mosquito Larvae Control: Mitigating Malaria Risk in Dar es Salaam, Tanzania  

OpenAIRE

Global commitment, political will and financial support to reduce the burden of malaria, a disease which kills about one million people each year, have reached an unprecedented level. Although global malaria eradication appears to be a distant goal, there are promising efforts towards regional control and local elimination of the disease. Sub-Saharan Africa (SSA) is the region with the world’s highest malaria burden, as well as the world’s fastest growing cities. Rapid urbanisation brings...

Dongus, Stefan

2009-01-01

139

Plant extracts as potential mosquito larvicides.  

Science.gov (United States)

Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed. PMID:22771587

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-05-01

140

Wolbachia-a foe for mosquitoes  

Science.gov (United States)

Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmful vectors. Recently, a novel approach to control mosquitoes by transinfection of life shortening maternally transmitted endo-symbiont Wolbachia wMelPop strain from fruitfly Drosophila into mosquito population has been developed by researchers. The wMelPop strain up-regulated the immune gene expression in mosquitoes thereby reducing the dengue and Chickungunya viral replication in Aedes aegypti, and also it significantly reduced the Plasmodium level in Anopheles gambiae. Here, we discuss the strategy of using Wolbachia in control of vector-borne diseases of mosquitoes.

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

2014-01-01

141

A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies  

OpenAIRE

Abstract Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector co...

Ogoma Sheila B; Moore Sarah J; Maia Marta F

2012-01-01

142

A rapid knockdown effect of Penicillium citrinum for control of the mosquito Culex quinquefasciatus in Thailand.  

Science.gov (United States)

Twenty local isolates of entomopathogenic fungi were determined for control of the larvae and adults of Culex quinquefasciatus. In a laboratory experiment, a Penicillium sp. CM-010 caused 100% mortality of third-instar larvae within 2 h using a conidial suspension of 1 × 10? conidia ml?¹. Its LC?? was 3 × 10? conidia ml?¹, and the lethal time (LT??) was 1.06 h. Cloning and sequencing of its internal transcribed spacer region indicated that this Penicillium species is Penicillium citrinum (100% identity in 434 bp). Mortality of the adult was highest with Aspergillus flavus CM-011 followed with Metarhizium anisopliae CKM-048 from 1 × 10? conidia ml?¹. P. citrinum CM-010 at 1 × 10? conidia ml?¹ killed 100% larvae within 2 h while Bacillus thuringiensis var. israelensis at 5 ITU ml?¹ required 24 h. This P. citrinum CM-010 also greatly reduced survival of C. quinquefasciatus larvae in an unreplicated field test. Light and transmission electron micrographs showed that the fungal conidia were ingested by the larvae and deposited in the gut. The metabolite patulin was produced by P. citrinum CM-010 instead of citrinin. PMID:24078109

Maketon, Monchan; Amnuaykanjanasin, Alongkorn; Kaysorngup, Achirayar

2014-02-01

143

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)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish 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

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

1463-14-01

144

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

OpenAIRE

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...

Cheung, P. Y.; Hammock, B. D.

1985-01-01

145

Comparación morfológica e histológica del tubo digestivo de Gambusia puncticulata y Girardinus metallicus (Cyprinodontiformes: Poeciliidae, peces utilizados en el control biológico de mosquitos  

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Full Text Available Se describió y comparó la morfología e histología del tubo digestivo de Gambusia puncticulata y Girardinus metallicus, peces utilizados en el control biológico de larvas de mosquitos en Cuba, y se relacionó con los hábitos alimentarios de cada especie. Gambusia puncticulata tiene un intestino corto y grueso, característico de las especies carnívoras y Girardinus metallicus posee un intestino alargado y delgado arrollado en forma de espiral como corresponde a los peces omnívoros. Se observó que el patrón histológico del intestino en ambas especies es muy simple, sin embargo, Gambusia puncticulata presentó gran cantidad de microvellosidades de tipo ramificadas, al compararla con Girardinus metallicus, lo que aumenta de esta forma el rendimiento digestivo de su relativamente más corto, tubo digestivo.The morphology and histology of the digestive tract of Gambusia puncticulata and Girardinus metallicus fishes used in the biological control of mosquito larvae in Cuba, were described and compared. They were related to the food habits of each species. Gambusia puncticulata has a short and thick intestine, which is characteristic of the carnivorous species, whereas Girardinus metallicus has an elongate and thin spiral rolled up intestine as it corresponds to the omnivorous fishes. It was observed that the histological pattern of the intestine in both species is very simple; however, Gambusia puncticulata presented a great number of ramified microhairiness on comparing it with Girardinus metallicus, which increases this way the digestive yield of its relatively shorter digestive tract.

Jinnay Rodríguez Rodríguez

2004-04-01

146

Comparación morfológica e histológica del tubo digestivo de Gambusia puncticulata y Girardinus metallicus (Cyprinodontiformes: Poeciliidae), peces utilizados en el control biológico de mosquitos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se describió y comparó la morfología e histología del tubo digestivo de Gambusia puncticulata y Girardinus metallicus, peces utilizados en el control biológico de larvas de mosquitos en Cuba, y se relacionó con los hábitos alimentarios de cada especie. Gambusia puncticulata tiene un intestino corto [...] y grueso, característico de las especies carnívoras y Girardinus metallicus posee un intestino alargado y delgado arrollado en forma de espiral como corresponde a los peces omnívoros. Se observó que el patrón histológico del intestino en ambas especies es muy simple, sin embargo, Gambusia puncticulata presentó gran cantidad de microvellosidades de tipo ramificadas, al compararla con Girardinus metallicus, lo que aumenta de esta forma el rendimiento digestivo de su relativamente más corto, tubo digestivo. Abstract in english The morphology and histology of the digestive tract of Gambusia puncticulata and Girardinus metallicus fishes used in the biological control of mosquito larvae in Cuba, were described and compared. They were related to the food habits of each species. Gambusia puncticulata has a short and thick inte [...] stine, which is characteristic of the carnivorous species, whereas Girardinus metallicus has an elongate and thin spiral rolled up intestine as it corresponds to the omnivorous fishes. It was observed that the histological pattern of the intestine in both species is very simple; however, Gambusia puncticulata presented a great number of ramified microhairiness on comparing it with Girardinus metallicus, which increases this way the digestive yield of its relatively shorter digestive tract.

Jinnay, Rodríguez Rodríguez; Efraín, González; Natividad, Hernández Contreras; Virginia, Capó; Israel, García.

2004-04-01

147

The vasa regulatory region mediates germline expression and maternal transmission of proteins in the malaria mosquito Anopheles gambiae: a versatile tool for genetic control strategies  

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Full Text Available Abstract Background Germline specific promoters are an essential component of potential vector control strategies which function by genetic drive, however suitable promoters are not currently available for the main human malaria vector Anopheles gambiae. Results We have identified the Anopheles gambiae vasa-like gene and found its expression to be specifically localized to both the male and female gonads in adult mosquitoes. We have functionally characterised using transgenic reporter lines the regulatory regions required for driving transgene expression in a pattern mirroring that of the endogenous vasa locus. Two reporter constructs indicate the existence of distinct vasa regulatory elements within the 5' untranslated regions responsible not only for the spatial and temporal but also for the sex specific germline expression. vasa driven eGFP expression in the ovary of heterozygous mosquitoes resulted in the progressive accumulation of maternal protein and transcript in developing oocytes that were then detectable in all embryos and neonatal larvae. Conclusion We have characterized the vasa regulatory regions that are not only suited to drive transgenes in the early germline of both sexes but could also be utilized to manipulate the zygotic genome of developing embryos via maternal deposition of active molecules. We have used computational models to show that a homing endonuclease-based gene drive system can function in the presence of maternal deposition and describe a novel non-invasive control strategy based on early vasa driven homing endonuclease expression.

Burt Austin

2009-07-01

148

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)

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.

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

2015-02-01

149

Spatiotemporal monitoring of floodwater mosquito dispersal in Osijek, Croatia.  

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This paper demonstrates the possibility of using geostatistics to monitor the dispersal of mosquitoes for mosquito control programs at the municipal level. The case study objective was to quantify the dispersal of floodwater mosquitoes from the natural marshland Kopacki rit into the city of Osijek, Croatia, and to analyze the main factors controlling it. Fifty thousand adult Aedes vexans, Ochlerotatus sticticus, and Ochlerotatus caspius mosquitoes were marked with a powdered fluorescent pigment and released from the southern part of Kopacki rit on April 28, 2004. Forty CO2-baited Centers for Disease Control and Prevention traps were set in the area of the municipality of Osijek (171 km2) and were monitored for 10 days. A total of 582,471 mosquitoes were captured and examined in the laboratory. The mosquito counts from different sites were then interpolated using ordinary kriging and visualized dynamically to detect the dominant migrational directions. Mosquito dispersal and frequency were greatly influenced by wind speed (r = 0.82). The marked mosquitoes were found at 12 sites located from 1 km to 11.7 km away from the release point. The recapture rate was 0.044% (54% Oc. sticticus, 32% Ae. vexans, and 14% Oc. caspius). Based on the Lincoln index, the estimated total population size for floodwater mosquitoes in the study area ranged from 875 million to 2.0 billion mosquitoes. Limitations of the approach, recommendations for the improvement of the monitoring network, and spatial predictions are further discussed. PMID:17847840

Bogojevi?, Mirta Sudari?; Hengl, Tomislav; Merdi?, Enrih

2007-06-01

150

Ecology of mosquitoes of Midwestern Nigeria  

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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

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

2005-03-01

151

Olfaction in mosquitoes  

OpenAIRE

Female mosquitoes are vectors of diseases, affecting both livestock and humans. The host-seeking and identification behaviors of mosquitoes are mediated mainly by olfactory cues. The peripheral olfactory organs of mosquitoes which perceive olfactory cues are the antennae and maxillary palps. These appendages bear numerous hair shaped structures, sensilla, in which olfactory receptor neurons (ORNs) are housed. The ORNs detect and discriminate various odorant molecules and send information rega...

Ghaninia, Majid

2007-01-01

152

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

Science.gov (United States)

The voltage-sensitive sodium (Na+) channel (Vssc) is the target site of pyrethroid insecticides. Pest insects develop resistance to this class of insecticide by acquisition of one or multiple amino acid substitution(s) in this channel. In Southeast Asia, two major Vssc types confer pyrethroid resistance in the dengue mosquito vector Aedes aegypti, namely, S989P+V1016G and F1534C. We expressed several types of Vssc in Xenopus oocytes and examined the effect of amino acid substitutions in Vssc on pyrethroid susceptibilities. S989P+V1016G and F1534C haplotypes reduced the channel sensitivity to permethrin by 100- and 25-fold, respectively, while S989P+V1016G+F1534C triple mutations reduced the channel sensitivity to permethrin by 1100-fold. S989P+V1016G and F1534C haplotypes reduced the channel sensitivity to deltamethrin by 10- and 1-fold (no reduction), respectively, but S989P+V1016G+F1534C triple mutations reduced the channel sensitivity to deltamethrin by 90-fold. These results imply that pyrethroid insecticides are highly likely to lose their effectiveness against A. aegypti if such a Vssc haplotype emerges as the result of a single crossing-over event; thus, this may cause failure to control this key mosquito vector. Here, we strongly emphasize the importance of monitoring the occurrence of triple mutations in Vssc in the field population of A. aegypti. PMID:25166902

Hirata, Koichi; Komagata, Osamu; Itokawa, Kentaro; Yamamoto, Atsushi; Tomita, Takashi; Kasai, Shinji

2014-08-01

153

A Single Crossing-Over Event in Voltage-Sensitive Na+ Channel Genes May Cause Critical Failure of Dengue Mosquito Control by Insecticides  

Science.gov (United States)

The voltage-sensitive sodium (Na+) channel (Vssc) is the target site of pyrethroid insecticides. Pest insects develop resistance to this class of insecticide by acquisition of one or multiple amino acid substitution(s) in this channel. In Southeast Asia, two major Vssc types confer pyrethroid resistance in the dengue mosquito vector Aedes aegypti, namely, S989P+V1016G and F1534C. We expressed several types of Vssc in Xenopus oocytes and examined the effect of amino acid substitutions in Vssc on pyrethroid susceptibilities. S989P+V1016G and F1534C haplotypes reduced the channel sensitivity to permethrin by 100- and 25-fold, respectively, while S989P+V1016G+F1534C triple mutations reduced the channel sensitivity to permethrin by 1100-fold. S989P+V1016G and F1534C haplotypes reduced the channel sensitivity to deltamethrin by 10- and 1-fold (no reduction), respectively, but S989P+V1016G+F1534C triple mutations reduced the channel sensitivity to deltamethrin by 90-fold. These results imply that pyrethroid insecticides are highly likely to lose their effectiveness against A. aegypti if such a Vssc haplotype emerges as the result of a single crossing-over event; thus, this may cause failure to control this key mosquito vector. Here, we strongly emphasize the importance of monitoring the occurrence of triple mutations in Vssc in the field population of A. aegypti. PMID:25166902

Hirata, Koichi; Komagata, Osamu; Itokawa, Kentaro; Yamamoto, Atsushi; Tomita, Takashi; Kasai, Shinji

2014-01-01

154

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

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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.

Reddy Vamsi P

2011-07-01

155

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)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish 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.

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

2008-04-01

156

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)

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.

Domingo Montada Dorta

2008-04-01

157

Mosquito control insecticides: a probabilistic ecological risk assessment on drift exposures of naled, dichlorvos (naled metabolite) and permethrin to adult butterflies.  

Science.gov (United States)

A comprehensive probabilistic terrestrial ecological risk assessment (ERA) was conducted to characterize the potential risk of mosquito control insecticide (i.e., naled, it's metabolite dichlorvos, and permethrin) usage to adult butterflies in south Florida by comparing the probability distributions of environmental exposure concentrations following actual mosquito control applications at labeled rates from ten field monitoring studies with the probability distributions of butterfly species response (effects) data from our laboratory acute toxicity studies. The overlap of these distributions was used as a measure of risk to butterflies. The long-term viability (survival) of adult butterflies, following topical (thorax/wings) exposures was the environmental value we wanted to protect. Laboratory acute toxicity studies (24-h LD50) included topical exposures (thorax and wings) to five adult butterfly species and preparation of species sensitivity distributions (SSDs). The ERA indicated that the assessment endpoint of protection, of at least 90% of the species, 90% of the time (or the 10th percentile from the acute SSDs) from acute naled and permethrin exposures, is most likely not occurring when considering topical exposures to adults. Although the surface areas for adulticide exposures are greater for the wings, exposures to the thorax provide the highest potential for risk (i.e., SSD 10th percentile is lowest) for adult butterflies. Dichlorvos appeared to present no risk. The results of this ERA can be applied to other areas of the world, where these insecticides are used and where butterflies may be exposed. Since there are other sources (e.g., agriculture) of pesticides in the environment, where butterfly exposures will occur, the ERA may under-estimate the potential risks under real-world conditions. PMID:25261815

Hoang, T C; Rand, G M

2015-01-01

158

DsRed2 transient expression in Culex quinquefasciatus mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2013-06-01

159

Biosynthesis of 130-kilodalton mosquito larvicide in the cyanobacterium Agmenellum quadruplicatum PR-6.  

OpenAIRE

The 130-kilodalton mosquito larvicidal gene, cloned from Bacillus thuringiensis var. israelensis, was introduced into the cyanobacterium Agmenellum quadruplicatum PR-6 by plasmid transformation. Transformed cells synthesized 130-kilodalton delta-endotoxin protein and showed mosquito larvicidal activity. Results demonstrate a potential use of a cyanobacterium for biological control of mosquitoes.

Angsuthanasombat, C.; Panyim, S.

1989-01-01

160

Biosynthesis of 130-kilodalton mosquito larvicide in the cyanobacterium Agmenellum quadruplicatum PR-6.  

Science.gov (United States)

The 130-kilodalton mosquito larvicidal gene, cloned from Bacillus thuringiensis var. israelensis, was introduced into the cyanobacterium Agmenellum quadruplicatum PR-6 by plasmid transformation. Transformed cells synthesized 130-kilodalton delta-endotoxin protein and showed mosquito larvicidal activity. Results demonstrate a potential use of a cyanobacterium for biological control of mosquitoes. PMID:2552921

Angsuthanasombat, C; Panyim, S

1989-09-01

161

Methionine: a new biopesticide for use in mosquito management  

Science.gov (United States)

Mosquito larvicides are an effective means of source reduction, controlling the population size so that the number of adult females that are present to bite and potentially spread pathogenic organisms is decreased. Currently utilized mosquito larvicides include insect growth regulators, organophosph...

162

Predicting mosquito infection from Plasmodium falciparum gametocyte density and estimating the reservoir of infection  

OpenAIRE

Transmission reduction is a key component of global efforts to control and eliminate malaria; yet, it is unclear how the density of transmission stages (gametocytes) influences infection (proportion of mosquitoes infected). Human to mosquito transmission was assessed using 171 direct mosquito feeding assays conducted in Burkina Faso and Kenya. Plasmodium falciparum infects Anopheles gambiae efficiently at low densities (4% mosquitoes at 1/µl blood), although substantially more (>200/µl) ...

Churcher, Thomas S.; Bousema, Teun; Walker, Martin; Drakeley, Chris; Schneider, Petra; Oue?draogo, Andre? Lin; Basa?n?ez, Mari?a-gloria

2013-01-01

163

[Mosquitoes as vectors for exotic pathogens in Germany].  

Science.gov (United States)

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

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

2014-05-01

164

Play the Mosquito Game  

Science.gov (United States)

... of Nobel Prizes and Laureates All Educational Productions Physics Prize Related Chemistry Prize Related Medicine Prize Related ... and Work Teachers' Questionnaire Malaria Play the Mosquito Game Play the Parasite Game About the games Malaria ...

165

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

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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.

Pon Jennifer

2011-10-01

166

Taxis assays measure directional movement of mosquitoes to olfactory cues  

OpenAIRE

Malaria control methods targeting indoor-biting mosquitoes have limited impact on vectors that feed and rest outdoors. Exploiting mosquito olfactory behaviour to reduce blood-feeding outdoors might be a sustainable approach to complement existing control strategies. Methodologies that can objectively quantify responses to odour under realistic field conditions and allow high-throughput screening of many compounds are required for development of effective odour-based control strategies. The ol...

Lorenz, Lena M.; Keane, Aidan; Moore, Jason D.; Munk, Cristina J.; Seeholzer, Laura; Mseka, Antony; Simfukwe, Emmanuel; Ligamba, Joseph; Turner, Elizabeth L.; Biswaro, Lubandwa R.; Okumu, Fredros O.; Killeen, Gerry F.; Mukabana, Wolfgang R.; Moore, Sarah J.

2013-01-01

167

Mosquito attractant blends to trap host seeking Aedes aegypti.  

Science.gov (United States)

Aedes aegypti is the key vector of three important arboviral diseases -dengue, yellow fever and chikungunya. To identify volatile chemicals which could be used in odour based traps for Aedes mosquito surveillance, a few synthetic compounds and compound blends have been evaluated in an indigenously designed olfactometer. A total of 24 compounds and seven compound blends were screened against unfed adult female Ae. aegypti mosquitoes for attraction and compared with control group. The attractancy or repellency index of the test material to mosquitoes was calculated and rated them as class-1, class-2 and class-3 with rating values ranging 1-15, 16-33 and 34-100 respectively. Out of the 24 compounds tested, six were showing significant attractancy (P?compounds showed significant repellency (P?repellent action against Ae. aegypti. All the seven blends showed significant mosquito attractancy (P?mosquito attractancy. PMID:23306388

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

2013-03-01

168

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

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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.

Pigeon Olivier

2008-06-01

169

The Knowledge and Experience of Dengue Mosquitoes among Housewives.  

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Full Text Available Dengue Hemorrhagic Fever (DHF prevention programs in Semarang, were focused through controlling mosquito breeding sites (PSN, but the implementation of PSN was not become a habit in every household. The objective of this study was to explore knowledge and experience of dengue mosquitoes among housewives in the endemic villages.The research was using qualitative methods. Subjects of the study were 17 housewives which selected by purposive sampling. The data collection was carried in Sendangmulyo village, Semarang, through observation, focus groups discussions, and indepth interviews. The techniques used to test data validity were triangulation and member checking method. Data were analyzed using content analysis approached. The results showed that housewives classifying mosquito based on time occurrence whether the presence of mosquito in environment was perceived naturally. Unoptimalized PSN behavior was based on the lack of housewives knowledge on larvae development stages. Mosquito was not considered as a threatening because night mosquito biting was directly more disturbing rather than day mosquitoes’. Health promotion program could increase dasa wisma cadres knowledge and skill, particularly on mosquito life cycle and the correct stages of PSN behavior. This study did not distinguish the demographic characteristics of informants. Further reserch could explore it or develop media based on local knowledge and experience.

Atik Triratnawati

2011-06-01

170

A lethal ovitrap-based mass trapping scheme for dengue control in Australia: II. Impact on populations of the mosquito Aedes aegypti.  

Science.gov (United States)

In Cairns, Australia, the impacts on Aedes aegypti L. (Diptera: Culicidae) populations of two types of 'lure & kill' (L&K) lethal ovitraps (LOs), the standard lethal ovitrap (SLO) and the biodegradable lethal ovitrap (BLO) were measured during three mass-trapping interventions. To assess the efficacy of the SLO, two interventions (one dry season and one wet season) were conducted in three discrete areas, each lasting 4 weeks, with the following treatments: (i) SLOs (>200 traps, approximately 4/premise), BG-sentinel traps (BGSs; approximately 15, 1/premise) and larval control (container reduction and methoprene treatment) and (ii) larval control alone, and (iii) untreated control. Female Ae. aegypti populations were monitored for 4 weeks pre- and post-treatment in all three areas using BGSs and sticky ovitraps (SOs) or non-lethal regular ovitraps (ROs). In the dry season, 206 SLOs and 15 BGSs set at 54 and 15 houses, respectively, caught and killed an estimated 419 and 73 female Ae. aegypti, respectively. No significant decrease in collection size of female Ae. aegypti could be attributed to the treatments. In the wet season, 243 SLOs and 15 BGSs killed approximately 993 and 119 female Ae. aegypti, respectively. The mean number of female Ae. aegypti collected after 4 weeks with SOs and BGSs was significantly less than the control (LSD post-hoc test). The third mass-trapping intervention was conducted using the BLO during the wet season in Cairns. For this trial, three treatment areas were each provided with BLOs (>500, approximately 4/premise) plus larval control, and an untreated control area was designated. Adult female Ae. aegypti were collected for 4 weeks pre- and post-treatment using 15 BGSs and 20 SOs. During this period, 53.2% of BLOs contained a total of 6654 Ae. aegypti eggs. Over the intervention period, collections of Ae. aegypti in the treatment areas were significantly less than in the control area for BGSs but not SOs. An influx of relatively large numbers of young females may have confounded the measurement of changes in populations of older females in these studies. This is an important issue, with implications for assessing delayed action control measures, such as LOs and parasites/pathogens that aim to change mosquito age structure. Finally, the high public acceptability of SLOs and BLOs, coupled with significant impacts on female Ae. aegypti populations in two of the three interventions reported here, suggest that mass trapping with SLOs and BLOs can be an effective component of a dengue control strategy. PMID:19941596

Rapley, L P; Johnson, P H; Williams, C R; Silcock, R M; Larkman, M; Long, S A; Russell, R C; Ritchie, S A

2009-12-01

171

Flavivirus-mosquito interactions.  

Science.gov (United States)

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. PMID:25421894

Huang, Yan-Jang S; Higgs, Stephen; Horne, Kate McElroy; Vanlandingham, Dana L

2014-11-01

172

Flavivirus-Mosquito Interactions  

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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.

Yan-Jang S. Huang

2014-11-01

173

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

174

UV light and urban pollution: Bad cocktail for mosquitoes?  

Energy Technology Data Exchange (ETDEWEB)

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.

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

175

Pesticides and public health: integrated methods of mosquito management.  

OpenAIRE

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...

Rose, R. I.

2001-01-01

176

Identification of mosquito repellent odours from Ocimum forskolei  

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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.

Glinwood Robert

2011-09-01

177

How Mosquitoes Detect People  

Science.gov (United States)

... video): http://www.youtube.com/watch?v=7wijX9WZUpc Malaria Vaccine Found Safe and Protective: http://www.nih.gov/researchmatters/august2013/08192013malaria.htm Infection Makes Mosquitoes Immune to Malaria Parasites: http://www.nih.gov/researchmatters/may2013/05202013malaria. ...

178

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

Directory of Open Access Journals (Sweden)

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.

KARTIKA SENJARINI

2013-11-01

179

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)

180

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)

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

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

2014-03-01

181

The Knowledge and Experience of Dengue Mosquitoes among Housewives.  

OpenAIRE

Dengue Hemorrhagic Fever (DHF) prevention programs in Semarang, were focused through controlling mosquito breeding sites (PSN), but the implementation of PSN was not become a habit in every household. The objective of this study was to explore knowledge and experience of dengue mosquitoes among housewives in the endemic villages.The research was using qualitative methods. Subjects of the study were 17 housewives which selected by purposive sampling. The data collection was carried in Sendan...

Atik Triratnawati; Aryani Pujiyanti

2011-01-01

182

UV light and urban pollution: bad cocktail for mosquitoes?  

Science.gov (United States)

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

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

183

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

Science.gov (United States)

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

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

2011-03-01

184

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)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

2006-08-01

185

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.

186

Trapping mosquitoes using milk products as odour baits in western Kenya  

OpenAIRE

Abstract Background Ample evidence has shown that blood seeking mosquitoes locate their hosts by following odours produced by the hosts. Odour baited traps would therefore, provide a solution in controlling diseases spread by mosquitoes. Comparative studies were undertaken to determine the relative efficacies of two odour baits i.e. Limburger cheese and African traditional milk cream in trapping mosquitoes in the field in western Kenya. Method Comparative effica...

Owino Eunice A

2010-01-01

187

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

OpenAIRE

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 ...

Frentiu, Francesca D.; Zakir, Tasnim; Walker, Thomas; Popovici, Jean; Pyke, Alyssa T.; Den Hurk, Andrew; Mcgraw, Elizabeth A.; O Neill, Scott L.

2014-01-01

188

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

OpenAIRE

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...

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

2014-01-01

189

The roles of kairomones, synomones and pheromones in the chemically-mediated behaviour of male mosquitoes.  

Science.gov (United States)

Despite decades of intensive study of the chemical ecology of female mosquitoes, relatively little is known about the chemical ecology of males. This short review summarizes the current state of knowledge of the chemicals that mediate male mosquito behaviour. Various trophic interactions including insect-plant, insect-host, and insect-insect responses are emphasized. The relevance of the chemical ecology of male mosquitoes in the context of vector control programmes is discussed. PMID:24055544

Pitts, R Jason; Moz?raitis, Raimondas; Gauvin-Bialecki, Anne; Lempérière, Guy

2014-04-01

190

Molecular Genetic Analysis of Midgut Serine Proteases in Aedes aegypti Mosquitoes  

OpenAIRE

Digestion of blood meal proteins by midgut proteases provides anautogenous mosquitoes with the nutrients required to complete the gonotrophic cycle. Inhibition of protein digestion in the midgut of blood feeding mosquitoes could therefore provide a strategy for population control. Based on recent reports indicating that the mechanism and regulation of protein digestion in blood fed female Aedes aegypti mosquitoes is more complex than previously thought, we used a robust RNAi knockdown method ...

Isoe, Jun; Rasco?n, Alberto A.; Kunz, Susan; Miesfeld, Roger L.

2009-01-01

191

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

OpenAIRE

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...

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

2010-01-01

192

Tracking the mutual shaping of the technical and social dimensions of solar-powered mosquito trapping systems (SMoTS) for malaria control on Rusinga Island, western Kenya.  

Science.gov (United States)

BackgroundThere has been increasing effort in recent years to incorporate user needs in technology design and re-design. This project employed a bottom-up approach that engaged end users from the outset. Bottom-up approaches have the potential to bolster novel interventions and move them towards adaptive and evidence-based strategies. The present study concerns an innovative use of solar-powered mosquito trapping systems (SMoTS) to control malaria in western Kenya. Our paper highlights the co-dependence of research associated with the development of the SMoTS technology on one hand and research for enhancing the sustainable uptake of that very same intervention within the community on the other.MethodsDuring the pre-intervention year, we examined the design, re-design and piloting of a novel technology to generate lessons for malaria elimination on Rusinga Island. Initial ideas about many technological necessities were evaluated and re-designed following feedback from various sources, including technical and social research as well as broader interactions with the social environment. We documented the interlocking of the multiple processes and activities that took place through process observation and document reviews. We analysed the data within the conceptual framework of system innovation by identifying mutual shaping between technical and social factors.ResultsOur findings illustrate how various project stakeholders including project staff, collaborators, donor, and community members simultaneously pursued interdependent technological transformations and social interests. In the ongoing process, we observed how partial outcomes in the technological domain influenced social events at a later phase and vice versa.ConclusionsLooking at malaria intervention projects employing novel technologies as niches that may evolve towards system innovation, helps to reveal interrelations between the various technical and social aspects. Revealing these interrelations requires a different role for research and different perspective on innovation where innovation is more than the technical aspects. This approach therefore requires that research is designed in a way that enables obtaining feedback from both aspects. PMID:25404420

Oria, Prisca A; Hiscox, Alexandra; Alaii, Jane; Ayugi, Margaret; Mukabana, Wolfgang; Takken, Willem; Leeuwis, Cees

2014-11-18

193

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

Science.gov (United States)

The survival characteristics of the mosquito Aedes aegypti affect transmission rates of dengue because transmission requires infected mosquitoes to survive long enough for the virus to infect the salivary glands. Mosquito survival is assumed to be high in tropical, dengue endemic, countries like Vietnam. However, the survival rates of wild populations of mosquitoes are seldom measured due the difficulty of predicting mosquito age. Hon Mieu Island in central Vietnam is the site of a pilot release of Ae. aegypti infected with a strain of Wolbachia pipientis bacteria (wMelPop) that induces virus interference and mosquito life-shortening. We used the most accurate mosquito age grading approach, transcriptional profiling, to establish the survival patterns of the mosquito population from the population age structure. Furthermore, estimations were validated on mosquitoes released into a large semi-field environment consisting of an enclosed house, garden and yard to incorporate natural environmental variability. Mosquito survival was highest during the dry/cool (January-April) and dry/hot (May-August) seasons, when 92 and 64% of Hon Mieu mosquitoes had survived to an age that they were able to transmit dengue (12 d), respectively. This was reduced to 29% during the wet/cool season from September to December. The presence of Ae. aegypti older than 12 d during each season is likely to facilitate the observed continuity of dengue transmission in the region. We provide season specific Ae. aegypti survival models for improved dengue epidemiology and evaluation of mosquito control strategies that aim to reduce mosquito survival to break the dengue transmission cycle. PMID:24551251

Hugo, Leon E; Jeffery, Jason A L; Trewin, Brendan J; Wockner, Leesa F; Nguyen, Thi Yen; Nguyen, Hoang Le; Nghia, Le Trung; Hine, Emma; Ryan, Peter A; Kay, Brian H

2014-02-01

194

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)

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.

R. H. Zimmerman

1997-01-01

195

Immune activation by life-shortening Wolbachia and reduced filarial competence in mosquitoes  

OpenAIRE

Wolbachia strain wMelPop reduces the longevity of its Drosophila melanogaster host and, when introduced into the mosquito Aedes aegypti, halves its life span. We show that wMelPop induces up-regulation of the mosquito's innate immune system and that its presence inhibits the development of filarial nematodes in the mosquito. These data suggest that wMelPop could be used in the global effort to eliminate lymphatic filariasis and possibly for the control of other mosquito-borne parasites where ...

Kambris, Z.; Cook, Pe; Phuc, Hk; Sinkins, Sp

2009-01-01

196

Immune activation by life-shortening Wolbachia and reduced filarial competence in mosquitoes.  

Science.gov (United States)

Wolbachia strain wMelPop reduces the longevity of its Drosophila melanogaster host and, when introduced into the mosquito Aedes aegypti, halves its life span. We show that wMelPop induces up-regulation of the mosquito's innate immune system and that its presence inhibits the development of filarial nematodes in the mosquito. These data suggest that wMelPop could be used in the global effort to eliminate lymphatic filariasis and possibly for the control of other mosquito-borne parasites where immune preactivation inhibits their development. The cost of constitutive immune up-regulation may contribute to the life-shortening phenotype. PMID:19797660

Kambris, Zakaria; Cook, Peter E; Phuc, Hoang K; Sinkins, Steven P

2009-10-01

197

Insecticide resistance in mosquitoes: impact, mechanisms, and research directions.  

Science.gov (United States)

Mosquito-borne diseases, the most well known of which is malaria, are among the leading causes of human deaths worldwide. Vector control is a very important part of the global strategy for management of mosquito-associated diseases, and insecticide application is the most important component in this effort. However, mosquito-borne diseases are now resurgent, largely because of the insecticide resistance that has developed in mosquito vectors and the drug resistance of pathogens. A large number of studies have shown that multiple, complex resistance mechanisms-in particular, increased metabolic detoxification of insecticides and decreased sensitivity of the target proteins-or genes are likely responsible for insecticide resistance. Gene overexpression and amplification, and mutations in protein-coding-gene regions, have frequently been implicated as well. However, no comprehensive understanding of the resistance mechanisms or regulation involved has yet been developed. This article reviews current knowledge of the molecular mechanisms, genes, gene interactions, and gene regulation governing the development of insecticide resistance in mosquitoes and discusses the potential impact of the latest research findings on the basic and practical aspects of mosquito resistance research. PMID:25564745

Liu, Nannan

2015-01-01

198

Use of an indigenous fish species, Fundulus zebrinus, in a mosquito abatement program: a field comparison with the mosquitofish, Gambusia affinis.  

Science.gov (United States)

Studies were conducted relating mosquito production in small ponds to presence or absence of larvivorous fishes. Data collected showed that native killifish and introduced mosquitofish controlled mosquito larvae at the same level and support the use of indigenous fish species in mosquito abatement programs. PMID:1357089

Nelson, S M; Keenan, L C

1992-09-01

199

Wolbachia enhances West Nile virus (WNV) infection in the mosquito Culex tarsalis.  

Science.gov (United States)

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 important WNV vector in North America. After inoculation into adult female mosquitoes, Wolbachia reached high titers and disseminated widely to numerous tissues including the head, thoracic flight muscles, fat body and ovarian follicles. Contrary to other systems, Wolbachia did not inhibit WNV in this mosquito. Rather, WNV infection rate was significantly higher in Wolbachia-infected mosquitoes compared to controls. Quantitative PCR of selected innate immune genes indicated that REL1 (the activator of the antiviral Toll immune pathway) was down regulated in Wolbachia-infected relative to control mosquitoes. This is the first observation of Wolbachia-induced enhancement of a human pathogen in mosquitoes, suggesting that caution should be applied before releasing Wolbachia-infected insects as part of a vector-borne disease control program. PMID:25010200

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

2014-07-01

200

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

Centers for Disease Control (CDC) Podcasts

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.

2007-12-10

201

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

Directory of Open Access Journals (Sweden)

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.

Walter J. Tabachnick

2013-01-01

202

Distribution of anopheline mosquitoes in Eritrea.  

Science.gov (United States)

The spatial distribution of anopheline mosquito species was studied throughout Eritrea during the 1999-2001 malaria transmission seasons from October to December for the highlands and western lowlands and February to April for the coastal region. Of the 302 villages sampled, 59 were visited in both the first and second year. Overall, 13 anopheline species were identified, with the Anopheles gambiae complex predominating during the first year (75.6%, n = 861) and the second year (91.9%, n = 1,262). Intrazonal variation accounted for 90% of the total variation in mosquito distribution. Polymerase chain reaction results indicated that 99% (n = 1,309) of the An. gambiae s.l. specimens were An. arabiensis, indicating that this was the only member of the gambiae complex present. There was a high degree of aggregation of anophelines within zones and villages, with more than 80% of the total anophelines being collected from less than 20% of the villages and from only 10% of the houses sampled. At least 80% of the anopheline mosquitoes were collected from grass-thatched Agudo-type housing. Vector abundance showed an inverse relationship with elevation, with highest densities in the low-lying western lowlands. Multiple regression analysis of log-transformed mean density of An. arabiensis with rainfall and the normalized difference vegetation index (NDVI) (average NDVI, minimum NDVI, and maximum NDVI) showed that these independent variables were not significantly associated with mosquito densities (R2 = 0.058). Our study contributes to the basic understanding of the ecology and distribution of malaria vectors with respect to species composition and spatial heterogeneities both that could be used to guide vector control operations in Eritrea. PMID:14628947

Shililu, Josephat; Ghebremeskel, Tewolde; Mengistu, Solomon; Fekadu, Helen; Zerom, Mehari; Mbogo, Charles; Githure, John; Gu, Weidong; Novak, Robert; Beier, John C

2003-09-01

203

Raised houses reduce mosquito bites.  

Science.gov (United States)

BACKGROUND: In many parts of continental Africa house construction does not appear to impede entry of malaria vectors and, given their generally late biting cycle, the great majority of transmission takes place indoors. In contrast, many houses in São Tomé, 140 km off the coast of Gabon, are raised on stilts and built of wooden planks. Building on stilts is a time-honoured, but largely untested, way of avoiding mosquito bites. Exposure may also be affected by mosquito activity times and age composition of host-seeking females. A study was therefore undertaken on the island of São Tomé to determine if exposure to Anopheles gambiae, the only vector on the island, varied with house construction or time of the night. METHODS: A series of all-night landing collections were undertaken out of doors at ground level, inside houses at ground level, on the verandas of, and inside houses built on stilts. The gonotrophic age of an unselected sample of insects from the first three hours of landing collection (18:00-21:00) was determined by dissection. In addition, 1,149 miniature light-trap collections were obtained from 125 houses in the study area. Numbers collected were related to house construction. RESULTS: Biting of An. gambiae took place primarily outside at ground level. Less than one third of biting occurred inside houses. Houses built on stilts had half the number of An. gambiae in them compared to those built at ground level. Conversely houses with an eaves gap had more An. gambiae in them than houses without such a gap. Gonotrophic age did not affect house entry rates in An. gambiae. House construction affected Culex quinquefasciatus less than An. gambiae. Mean density per house, derived from a series of 1,490 randomly assigned light-trap collections, was over-dispersed with 18% of houses having 70% of the vectors. CONCLUSION: House construction plays an important role in determining exposure to malaria vectors in São Tomé. Neighbours can have very different exposure levels. Recommendations for improvement in control are given. PMID:14667242

Charlwood, J Derek; Pinto, Joao; Ferrara, Patrica R; Sousa, Carla A; Ferreira, Conceicao; Gil, Vilfrido; Do Rosário, Virgillo E

2003-12-10

204

Raised houses reduce mosquito bites  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In many parts of continental Africa house construction does not appear to impede entry of malaria vectors and, given their generally late biting cycle, the great majority of transmission takes place indoors. In contrast, many houses in São Tomé, 140 km off the coast of Gabon, are raised on stilts and built of wooden planks. Building on stilts is a time-honoured, but largely untested, way of avoiding mosquito bites. Exposure may also be affected by mosquito activity times and age composition of host-seeking females. A study was therefore undertaken on the island of São Tomé to determine if exposure to Anopheles gambiae, the only vector on the island, varied with house construction or time of the night. Methods A series of all-night landing collections were undertaken out of doors at ground level, inside houses at ground level, on the verandas of, and inside houses built on stilts. The gonotrophic age of an unselected sample of insects from the first three hours of landing collection (18:00–21:00 was determined by dissection. In addition, 1,149 miniature light-trap collections were obtained from 125 houses in the study area. Numbers collected were related to house construction. Results Biting of An. gambiae took place primarily outside at ground level. Less than one third of biting occurred inside houses. Houses built on stilts had half the number of An. gambiae in them compared to those built at ground level. Conversely houses with an eaves gap had more An. gambiae in them than houses without such a gap. Gonotrophic age did not affect house entry rates in An. gambiae. House construction affected Culex quinquefasciatus less than An. gambiae. Mean density per house, derived from a series of 1,490 randomly assigned light-trap collections, was over-dispersed with 18% of houses having 70% of the vectors. Conclusion House construction plays an important role in determining exposure to malaria vectors in São Tomé. Neighbours can have very different exposure levels. Recommendations for improvement in control are given.

Gil Vilfrido

2003-12-01

205

Haemoproteus infections (Haemosporida, Haemoproteidae) kill bird-biting mosquitoes.  

Science.gov (United States)

Haemoproteus parasites (Haemosporida, Haemoproteidae) are widespread; some species cause severe diseases in avian hosts. Heavy Haemoproteus infections are often lethal for biting midges (Ceratopogonidae), which transmit avian haemoproteids, but there is no information regarding detrimental effect on other blood-sucking insects. We examined effects of Haemoproteus tartakovskyi (lineage hSISKIN1), Haemoproteus lanii (lineages hRB1and hRBS2) and Haemoproteus balmorali (lineage hCOLL3) on the survival of Ochlerotatus cantans, a widespread Eurasian mosquito. Wild-caught females were infected by allowing them to feed on naturally infected birds with light (0.01%) and high (3.0-9.6%) parasitaemia. Mosquitoes fed on uninfected birds were used as controls. Both experimental and control groups were maintained under the same laboratory conditions until 20 days post-exposure (dpe). Dead insects were counted daily and used for parasitological examination and PCR-based testing. No difference was discernible in the survival rate of control mosquitoes and those fed on meal with light parasitaemia. There was a highly significant difference in the survival rate between the control group and all groups fed on meals with high parasitaemia, with the greatest mortality reported 1-3 dpe. For 4 dpe, the percentage of survived control mosquitoes (88%) was 2.2-, 3.6- and 4-fold greater than that of groups fed on meals with high parasitaemia of H. balmorali, H. tartakovskyi and H. lanii, respectively. Numerous ookinetes were observed in the gut area and adjacent tissues located in the head, thorax and abdomen of infected insects 0.5-1 dpe. The migrating parasites damage organs throughout the entire body of mosquitoes; that is the main reason of mortality. To the end of this study, 46% of mosquitoes survived in control group, but the survival rates of experimental mosquitoes fed on meals with high parasitaemia were between 2.6- and 5.8-fold lower. This study indicates that widespread Haemoproteus infections are markedly virulent for bird-biting mosquitoes, which rapidly die after feeding on heavily infected blood meals. PMID:24337545

Valki?nas, Gediminas; Kazlauskien?, Rita; Bernotien?, Rasa; Bukauskait?, Dovil?; Palinauskas, Vaidas; Iezhova, Tatjana A

2014-03-01

206

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)

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.

José Luis Torres-Estrada

2003-12-01

207

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

Science.gov (United States)

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

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

2014-11-18

208

Reduction of mosquito biting-pressure: spatial repellents or mosquito traps? A field comparison of seven commercially available products in Israel.  

Science.gov (United States)

The present study assessed the personal protection efficiency of seven commercially available mosquito control devices (MCD) under field conditions in Israel. Trials were performed in a high biting-pressure area inhabited by large populations of mosquito and biting midge species, using human volunteers as bait in landing catch experiments. Results show that under minimal air-movement, three spatial repellent based products (ThermaCELL(®) Patio Lantern, OFF!(®) PowerPad lamp, and Terminix(®) ALLCLEAR Tabletop Mosquito Repeller) significantly reduced the biting-pressure (t-test - Prepelled significantly more mosquitoes then the Terminix ALLCLEAR Tabletop Mosquito Repeller (t-test, P<0.05). In contrast, mosquito traps using attracting cues to bait mosquitoes (Dynatrap(®), Vortex(®) Electronic Insect Trap, Blue Rhino(®) SV3100) either significantly increased or had no effect on the biting-pressure at short distances compared with the unprotected control. Trials conducted over large areas showed that only the Blue Rhino trap was able to significantly reduce the biting-pressure (40.1% reduction), but this was only when operating four units at the corners of an intermediate sized area. PMID:23545129

Revay, Edita E; Kline, Daniel L; Xue, Rui-De; Qualls, Whitney A; Bernier, Ulrich R; Kravchenko, Vasiliy D; Ghattas, Nina; Pstygo, Irina; Müller, Günter C

2013-07-01

209

Mosquito Surveillance Revealed Lagged Effects of Mosquito Abundance on Mosquito-Borne Disease Transmission: A Retrospective Study in Zhejiang, China  

OpenAIRE

Mosquito-borne diseases (MBDs) are still threats to public health in Zhejiang. In this study, the associations between the time-lagged mosquito capture data and MBDs incidence over five years were used to examine the potential effects of mosquito abundance on patterns of MBDs epidemiology in Zhejiang during 2008–2012. Light traps were used to collect adult mosquitoes at 11 cities. Correlation tests with and without time lag were performed to investigate the correlations between MBDs inciden...

Guo, Song; Ling, Feng; Hou, Juan; Wang, Jinna; Fu, Guiming; Gong, Zhenyu

2014-01-01

210

Identification of Belgian mosquito species (Diptera: Culicidae) by DNA barcoding.  

Science.gov (United States)

Since its introduction in 2003, DNA barcoding has proven to be a promising method for the identification of many taxa, including mosquitoes (Diptera: Culicidae). Many mosquito species are potential vectors of pathogens, and correct identification in all life stages is essential for effective mosquito monitoring and control. To use DNA barcoding for species identification, a reliable and comprehensive reference database of verified DNA sequences is required. Hence, DNA sequence diversity of mosquitoes in Belgium was assessed using a 658 bp fragment of the mitochondrial cytochrome oxidase I (COI) gene, and a reference data set was established. Most species appeared as well-supported clusters. Intraspecific Kimura 2-parameter (K2P) distances averaged 0.7%, and the maximum observed K2P distance was 6.2% for Aedes koreicus. A small overlap between intra- and interspecific K2P distances for congeneric sequences was observed. Overall, the identification success using best match and the best close match criteria were high, that is above 98%. No clear genetic division was found between the closely related species Aedes annulipes and Aedes cantans, which can be confused using morphological identification only. The members of the Anopheles maculipennis complex, that is Anopheles maculipennis s.s. and An. messeae, were weakly supported as monophyletic taxa. This study showed that DNA barcoding offers a reliable framework for mosquito species identification in Belgium except for some closely related species. PMID:25143182

Versteirt, V; Nagy, Z T; Roelants, P; Denis, L; Breman, F C; Damiens, D; Dekoninck, W; Backeljau, T; Coosemans, M; Van Bortel, W

2015-03-01

211

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

Science.gov (United States)

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

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

2015-01-01

212

Molecular Strategies for Interrupting Arthropod-Borne Virus Transmission by Mosquitoes  

OpenAIRE

Arthropod-borne virus (arbovirus) infections cause a number of emerging and resurgent human and veterinary infectious diseases. Traditional means of controlling arbovirus diseases include vaccination of susceptible vertebrates and mosquito control, but in many cases these have been unavailable or ineffective, and so novel strategies for disease control are needed. One possibility is genetic manipulation of mosquito vectors to render them unable to transmit arboviruses. This review describes r...

Blair, Carol D.; Adelman, Zachary N.; Olson, Ken E.

2000-01-01

213

Interdependence of domestic malaria prevention measures and mosquito-human interactions in urban Dar es Salaam, Tanzania  

OpenAIRE

Abstract Background Successful malaria vector control depends on understanding behavioural interactions between mosquitoes and humans, which are highly setting-specific and may have characteristic features in urban environments. Here mosquito biting patterns in Dar es Salaam, Tanzania are examined and the protection against exposure to malaria transmission that is afforded to residents by using an insecticide-treated net (ITN) is estimated. Methods Mosquito biti...

Mshinda Hassan; Mtasiwa Deo; Shirima Rudolf; Mayagaya Valeliana; Govella Nicodemus J; Emidi Basiliana; Chaki Prosper; Geissbühler Yvonne; Fillinger Ulrike; Lindsay Steven W; Kannady Khadija; de Castro Marcia; Tanner Marcel; Killeen Gerry F

2007-01-01

214

Attracting, Trapping and killing Disease-Transmitting Mosquitoes Using Odor-Baited Stations - The Ifakara Odor-Baited Stations.  

OpenAIRE

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 devic...

John Alex N; Madumla Edith P; Okumu Fredros O; Lwetoijera Dickson W; Sumaye Robert D

2010-01-01

215

Synergy in efficacy of fungal entomopathogens and permethrin against West African insecticide-resistant Anopheles gambiae mosquitoes  

OpenAIRE

Background: Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study investigated the compatibility of the pyrethroid insecticide permethrin and two mosquito-pathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, against a laboratory colony and field population...

Farenhorst, M.; Knols, B. G. J.; Thomas, M. B.; Howard, A. F. V.; Takken, W.; Rowland, M.; N Guessan, R.

2010-01-01

216

Statics and dynamics of malaria infection in Anopheles mosquitoes  

Directory of Open Access Journals (Sweden)

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.

Ellis McKenzie F

2004-06-01

217

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

Science.gov (United States)

Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cyclopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis albidus albidus did not survive under dry conditions and did not tolerate water extracted from artificial containers. M. longisetus survival was not severely reduced after desiccation or breeding in water from flower vases. The Neotropical cyclopoids D. uruguayensis and A. robustus can be considered good candidates and merit further research as biological control agents for mosquitoes. PMID:20073334

Tranchida, María C; Micieli, María V; Maciá, Arnaldo; García, Juan J

2009-12-01

218

Climate-based models for West Nile Culex mosquito vectors in the Northeastern US  

Science.gov (United States)

Climate-based models simulating Culex mosquito population abundance in the Northeastern US were developed. Two West Nile vector species, Culex pipiens and Culex restuans, were included in model simulations. The model was optimized by a parameter-space search within biological bounds. Mosquito population dynamics were driven by major environmental factors including temperature, rainfall, evaporation rate and photoperiod. The results show a strong correlation between the timing of early population increases (as early warning of West Nile virus risk) and decreases in late summer. Simulated abundance was highly correlated with actual mosquito capture in New Jersey light traps and validated with field data. This climate-based model simulates the population dynamics of both the adult and immature mosquito life stage of Culex arbovirus vectors in the Northeastern US. It is expected to have direct and practical application for mosquito control and West Nile prevention programs.

Gong, Hongfei; Degaetano, Arthur T.; Harrington, Laura C.

2011-05-01

219

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

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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.

Rina Marina

2012-12-01

220

Insecticide-treated nets can reduce malaria transmission by mosquitoes which feed outdoors.  

Science.gov (United States)

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 and malaria transmission to illustrate how ITNs can achieve communal suppression of malaria transmission exposure, even where mosquito evade them and personal protection is modest. We also review recent reports from Tanzania to show that conventional mosquito behavior measures can underestimate the potential of ITNs because they ignore the importance of human movements. PMID:20207866

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

2010-03-01

221

European Surveillance for West Nile Virus in Mosquito Populations  

Directory of Open Access Journals (Sweden)

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.

Nicholas Johnson

2013-10-01

222

Protocol for Mosquito Rearing (A. gambiae)  

OpenAIRE

This protocol describes mosquito rearing in the insectary. The insectary rooms are maintained at 28°C and ~80% humidity, with a 12 hr. day/night cycle. For this procedure, you'll need mosquito cages, 10% sterile sucrose solution, paper towels, beaker, whatman filter paper, glass feeders, human blood and serum, water bath, parafilm, distilled water, clean plastic trays, mosquito food (described below), mosquito net to cover the trays, vacuum, and a collection chamber to collect...

Das, Suchismita; Garver, Lindsey; Dimopoulos, George

2007-01-01

223

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

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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

Amul B. Patel

2011-04-01

224

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

OpenAIRE

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...

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

1994-01-01

225

New protective battle-dress impregnated against mosquito vector bites  

OpenAIRE

Abstract Background Mixing repellent and organophosphate (OP) insecticides to better control pyrethroid resistant mosquito vectors is a promising strategy developed for bed net impregnation. Here, we investigated the opportunity to adapt this strategy to personal protection in the form of impregnated clothes. Methods We compared standard permethrin impregnated uniforms with uniforms manually impregnated with the repellent KBR3023 alone and in combination with an...

Pennetier Cédric; Chabi Joseph; Martin Thibaud; Chandre Fabrice; Rogier Christophe; Hougard Jean-Marc; Pages Frédéric

2010-01-01

226

Linking mosquito infestation to resident socioeconomic status, knowledge, and source reduction practices in suburban Washington, DC.  

Science.gov (United States)

Eliminating water-holding containers where mosquitoes oviposit and develop (source reduction) can help manage urban disease-vector mosquitoes. Source reduction requires residents to be knowledgeable of effective practices and motivated to implement them. We tested relationships between demographics, resident knowledge, attitudes, and practices (KAP), and mosquito infestation by administering larval mosquito surveys and KAP questionnaires in Washington, DC. Respondents who reported practicing source reduction had lower numbers of pupae-positive containers and Culex pipiens-positive containers, but not Aedes albopictus-positive containers or water-holding containers, in their yards. When controlling for numbers of water-holding containers in statistical models, residents who reported source reduction had lower numbers of A. albopictus-positive containers in addition to numbers of pupae-positive containers and C. pipiens-positive containers. These results suggest that while active container reduction may be effective at reducing C. pipiens and overall pupal production, it may be offset by other resident activities that add containers to yards, and that source reduction that involves mosquito habitat management without outright container removal can also be effective at reducing A. albopictus. Source reduction was related to respondent knowledge of mosquitoes and, in particular, specific knowledge of mosquito development, which both varied with demographics alongside respondent motivation to control mosquitoes. Respondents from high socioeconomic status households reported greater knowledge but lower motivation than respondents from middle and low socioeconomic-status households. We conclude that mosquito-related education will help promote community-based container management as part of integrated mosquito management programs, particularly in middle and low socioeconomic status neighborhoods with lower knowledge and high motivation. PMID:23377982

Dowling, Zara; Armbruster, Peter; LaDeau, Shannon L; DeCotiis, Mark; Mottley, Jihana; Leisnham, Paul T

2013-03-01

227

Contrasting patterns of tolerance between chemical and biological insecticides in mosquitoes exposed to UV-A.  

Science.gov (United States)

Mosquitoes are vectors of major human diseases, such as malaria, dengue or yellow fever. Because no efficient treatments or vaccines are available for most of these diseases, control measures rely mainly on reducing mosquito populations by the use of insecticides. Numerous biotic and abiotic factors are known to modulate the efficacy of insecticides used in mosquito control. Mosquito breeding sites vary from opened to high vegetation covered areas leading to a large ultraviolet gradient exposure. This ecological feature may affect the general physiology of the insect, including the resistance status against insecticides. In the context of their contrasted breeding sites, we assessed the impact of low-energetic ultraviolet exposure on mosquito sensitivity to biological and chemical insecticides. We show that several mosquito detoxification enzyme activities (cytochrome P450, glutathione S-transferases, esterases) were increased upon low-energy UV-A exposure. Additionally, five specific genes encoding detoxification enzymes (CYP6BB2, CYP6Z7, CYP6Z8, GSTD4, and GSTE2) previously shown to be involved in resistance to chemical insecticides were found over-transcribed in UV-A exposed mosquitoes, revealed by RT-qPCR experiments. More importantly, toxicological bioassays revealed that UV-exposed mosquitoes were more tolerant to four main chemical insecticide classes (DDT, imidacloprid, permethrin, temephos), whereas the bioinsecticide Bacillus thuringiensis subsp. israelensis (Bti) appeared more toxic. The present article provides the first experimental evidence of the capacity of low-energy UV-A to increase mosquito tolerance to major chemical insecticides. This is also the first time that a metabolic resistance to chemical insecticides is linked to a higher susceptibility to a bioinsecticide. These results support the use of Bti as an efficient alternative to chemical insecticides when a metabolic resistance to chemicals has been developed by mosquitoes. PMID:23911355

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

2013-09-15

228

Impact of environment on mosquito response to pyrethroid insecticides: facts, evidences and prospects.  

Science.gov (United States)

By transmitting major human diseases such as malaria, dengue fever and filariasis, mosquito species represent a serious threat worldwide in terms of public health, and pose a significant economic burden for the African continent and developing tropical regions. Most vector control programmes aiming at controlling life-threatening mosquitoes rely on the use of chemical insecticides, mainly belonging to the pyrethroid class. However, resistance of mosquito populations to pyrethroids is increasing at a dramatic rate, threatening the efficacy of control programmes throughout insecticide-treated areas, where mosquito-borne diseases are still prevalent. In the absence of new insecticides and efficient alternative vector control methods, resistance management strategies are therefore critical, but these require a deep understanding of adaptive mechanisms underlying resistance. Although insecticide resistance mechanisms are intensively studied in mosquitoes, such adaptation is often considered as the unique result of the selection pressure caused by insecticides used for vector control. Indeed, additional environmental parameters, such as insecticides/pesticides usage in agriculture, the presence of anthropogenic or natural xenobiotics, and biotic interactions between vectors and other organisms, may affect both the overall mosquito responses to pyrethroids and the selection of resistance mechanisms. In this context, the present work aims at updating current knowledge on pyrethroid resistance mechanisms in mosquitoes and compiling available data, often from different research fields, on the impact of the environment on mosquito response to pyrethroids. Key environmental factors, such as the presence of urban or agricultural pollutants and biotic interactions between mosquitoes and their microbiome are discussed, and research perspectives to fill in knowledge gaps are suggested. PMID:23123179

Nkya, Theresia Estomih; Akhouayri, Idir; Kisinza, William; David, Jean-Philippe

2013-04-01

229

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)

Full Text Available SciELO Public Health | Language: Spanish Abstract in spanish 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.

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

2003-12-01

230

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)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish 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.

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

2003-12-01

231

Plasmodium knowlesi in humans, macaques and mosquitoes in peninsular Malaysia  

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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.

NorParina Ismail

2008-08-01

232

Evaluation of commercial products for personal protection against mosquitoes.  

Science.gov (United States)

Human landing catch studies were conducted in a semi-field setting to determine the efficacy of seven commercial products used for personal protection against mosquitoes. Experiments were conducted in two empty, insecticide free, mesh-enclosed greenhouses, in Israel, with either 1500 Aedes albopictus or 1500 Culex pipiens released on consecutive study nights. The products tested in this study were the OFF!(®) Clip-On™ Mosquito Repellent (Metofluthrin 31.2%) and the Terminix(®) ALLCLEAR(®) Sidekick Mosquito Repeller (Cinnamon oil 10.5%; Eugenol 13%; Geranium oil 21%; Peppermint 5.3%; Lemongrass oil 2.6%), which are personal diffusers; Super Band™ Wristband (22% Citronella oil) and the PIC(®) Citronella Plus Wristband (Geraniol 15%; Lemongrass oil 5%, Citronella oil 1%); the Sonic Insect Repeller Keychain; the Mosquito Guard Patch (Oil of Lemon Eucalyptus 80mg), an adhesive-backed sticker for use on textiles; and the Mosquito Patch (vitamin B1 300mg), a transdermal patch. It was determined that the sticker, transdermal patch, wristbands and sonic device did not provide significant protection to volunteers compared with the mosquito attack rate on control volunteers who were not wearing a repellent device. The personal diffusers: - OFF!(®) Clip-On™ and Terminix(®) ALLCLEAR(®) Sidekick - provided superior protection compared with all other devices in this study. These diffusers reduced biting on the arms of volunteers by 96.28% and 95.26% respectively, for Ae. albopictus, and by 94.94% and 92.15% respectively, for Cx. pipiens. In a second trial conducted to compare these devices directly, biting was reduced by the OFF!(®) Clip-On™ and the Terminix(®) ALLCLEAR(®) by 87.55% and 92.83%, respectively, for Ae. albopictus, and by 97.22% and 94.14%, respectively, for Cx. pipiens. There was no significant difference between the performances of the two diffusers for each species. PMID:23092689

Revay, Edita E; Junnila, Amy; Xue, Rui-De; Kline, Daniel L; Bernier, Ulrich R; Kravchenko, Vasiliy D; Qualls, Whitney A; Ghattas, Nina; Müller, Günter C

2013-02-01

233

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

OpenAIRE

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...

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

2012-01-01

234

Midgut Microbiota of the Malaria Mosquito Vector Anopheles gambiae and Interactions with Plasmodium falciparum Infection  

OpenAIRE

The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of ...

Boissie?re, Anne; Tchioffo, Majoline T.; Bachar, Dipankar; Abate, Luc; Marie, Alexandra; Nsango, Sandrine E.; Shahbazkia, Hamid R.; Awono-ambene, Parfait H.; Levashina, Elena A.; Christen, Richard; Morlais, Isabelle

2012-01-01

235

Rural buyers' perception about mosquito repellants  

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Full Text Available Mosquito repellants prevent mosquito bites and prevention of "man-mosquito contact" is a critical factor in transmission and spread of any disease through mosquitoes particularly in rural area. There has been a long standing 'bias' towards rural buyers. The rural markets are considered rigid in the nature but it is not the case in real sense. Marketing to rural buyers is not only a challenge to the marketers but to the manufacturers, communicators, national planners and economists as well. That is why it has been necessary to understand the various aspects of selected rural areas and consumption pattern for such a fast growing market i.e. mosquito repellants and rural buyers’ perception towards such urban products. The present paper aims to find out the factors influencing the purchase decisions of rural buyers for mosquito repellants and to study the perceptions of present and potential rural buyers' of selected mosquito repellant brands.

D. MEHTA

2010-06-01

236

Culicinae (Diptera: Culicidae Mosquitoes in Chabahar County, Sistan and Baluchistan Province, Southeastern Iran  

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Full Text Available   Abstract Background: Mosquito-borne diseases are a major public health threat in Iran. The objective of this study was to de­ter­mine the fauna of culicinae mosquitoes for future mosquito control programs."nMethods: Three genera and eleven species of the subfamily Culicinae (Diptera: Culicidae were collected by dipping tech­nique and identified in Chabahar County, Sistan and Baluchistan Province, southeastern Iran, during January, Feb­ru­ary, and March 2007."nResults: The collected species included:  Aedes vexans (new occurrence record for the province, Culex  arbieeni, Cx. bitaeniorhynchus, Cx. deserticola, Cx. hortensis, Cx. perexiguus, Cx. pipiens, Cx.  pseudovishnui, Cx. pusillus, Cx. quinquefasciatus, Cx. sinaiticus, Cx. theileri, Cx. tritaeniorhynchus, Culiseta longiareolata, Ochlerotatus cabal­lus, Oc. caspius, and Uranotaenia unguiculata."nConclusion: Our observations indicate that, in South of Iran hot and wet climatic conditions support the persistence of culicinae mosquitoes. As our study, regular monitoring of culicinae mosquitoes in this area could be the most use­ful for mosquito control and mosquito-borne disease prevention.

SH Moosa-Kazemi

2009-07-01

237

Chemicals of predatory mosquitofish (Gambusia affinis) influence selection of oviposition site by Culex mosquitoes.  

Science.gov (United States)

Ovipositing insects may avoid aquatic sites where there is high predation risk to their offspring, but the proximate mechanisms that mediate avoidance behavior are poorly resolved. We conducted an experiment to determine whether mosquitoes would reduce oviposition rates in pools containing chemicals of the mosquitofish (Gambusia affinis), a voracious predator that is widely employed to control mosquitoes. Experimental treatments consisted of outdoor pools that contained known concentrations of fish chemicals (low, medium, or high) or no fish chemicals (control). The pools were arranged in a randomized block design, and the number of mosquito larvae in each pool served as the response variable to estimate relative oviposition rate. Members of the Culex pipiens complex were the main colonizers of the pools. The mean number of larvae per pool differed among treatments (P = 0.026) and was about three times greater in control pools compared with those receiving medium and high concentrations of fish chemicals. Pairwise comparisons indicate that only medium and high treatments differed significantly from controls, suggesting that a threshold concentration exists below which mosquitoes cannot reliably detect predators. Our data suggest that the effectiveness of Gambusia affinis in controlling mosquitoes may be compromised if adult mosquitoes respond to fish stocking by shifting to nearby breeding sites that lack fish. We discuss issues conceming the use of Gambusia in biological control programs within the context of these new findings. PMID:12035927

Angelon, Kim A; Petranka, James W

2002-04-01

238

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  

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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.

Shimada Masaaki

2011-05-01

239

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

Science.gov (United States)

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

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

1990-01-01

240

Mediation of oviposition responses in the malaria mosquito Anopheles stephensi Liston by certain fatty acid esters.  

Science.gov (United States)

The chemical factors involved in oviposition site selection by mosquitoes have become the focus of interest in recent years, and considerable attention is paid to the chemical cues influencing mosquito oviposition. Studies on synthetic oviposition attractants/repellents of long-chain fatty acid esters against Anopheles stephensi are limited. Screening and identification of chemicals which potentially attract/repel the gravid females to/or from oviposition site could be exploited for eco-friendly mosquito management strategies. The ester compounds demonstrated their ability to repel and attract the gravid A. stephensi females in the treated substrates. Significant level of concentration-dependent negative oviposition response of mosquitoes to octadecyl propanoate, heptadecyl butanoate, hexadecyl pentanoate, and tetradecyl heptanoate were observed. In contrast, decyl undecanoate, nonyl dodecanoate, pentyl hexadecanoate, and propyl octadecanoate elicited concentration-dependent positive oviposition responses from the gravid mosquitoes. Forcing a female to retain her eggs due to unavailability of a suitable oviposition site and attracting them to lay the eggs in a baited ovitraps shall ensure effective control of mosquito breeding and population buildup because the oviposition bioassay target the most susceptible stage of an insect life cycle. Treating relatively smaller natural breeding sites with an effective repellent and placing ovitraps containing an attractant in combination with insect-growth regulator (IGR)/insecticide would be a promising method of mosquito management. PMID:18795330

Sharma, Kavita R; Seenivasagan, T; Rao, A N; Ganesan, K; Agrawal, O P; Prakash, Shri

2009-01-01

241

Antibiotics in ingested human blood affect the mosquito microbiota and capacity to transmit malaria.  

Science.gov (United States)

Malaria reduction is most efficiently achieved by vector control whereby human populations at high risk of contracting and transmitting the disease are protected from mosquito bites. Here, we identify the presence of antibiotics in the blood of malaria-infected people as a new risk of increasing disease transmission. We show that antibiotics in ingested blood enhance the susceptibility of Anopheles gambiae mosquitoes to malaria infection by disturbing their gut microbiota. This effect is confirmed in a semi-natural setting by feeding mosquitoes with blood of children naturally infected with Plasmodium falciparum. Antibiotic exposure additionally increases mosquito survival and fecundity, which are known to augment vectorial capacity. These findings suggest that malaria transmission may be exacerbated in areas of high antibiotic usage, and that regions targeted by mass drug administration programs against communicable diseases may necessitate increased vector control. PMID:25562286

Gendrin, Mathilde; Rodgers, Faye H; Yerbanga, Rakiswendé S; Ouédraogo, Jean Bosco; Basáñez, María-Gloria; Cohuet, Anna; Christophides, George K

2015-01-01

242

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

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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.

Endang Puji Astuti

2011-06-01

243

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

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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.

M. Zimba

2013-04-01

244

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

OpenAIRE

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 reco...

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

2013-01-01

245

Improvised microinjection technique for mosquito vectors  

Science.gov (United States)

Background & objectives: Bio-manipulation technique is of primary importance during the development of transgenic mosquitoes. The study describes the variable factors that influence the viability of medically important mosquito vectors during microinjection. Methods: Three mosquito vectors belonging to the genus Aedes, Anopheles and Culex were microinjected at different developmental stages of their life cycle viz., egg, larvae, pupae and adult. Results: The improvisations revealed an increased survivability of biomanipulated mosquitoes during the embryonic and adult microinjection. The study of injecting larvae and pupae resulted in poor survivability. Interpretation & conclusions: The microinjection protocol was successfully tested on three important mosquito vectors. The critical period after biomanipulation which contributes heavily for the survivability factor was evaluated. The results provide a common protocol for biomanipulation of three mosquito vectors with enhanced survivability. PMID:23391792

Sampath, Kumar S.; Puttaraju, H. P.

2012-01-01

246

Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay  

OpenAIRE

Mosquitoes transmit a number of distinct viruses including important human pathogens such as West Nile virus, dengue virus, and chickungunya virus. Many of these viruses have intensified in their endemic ranges and expanded to new territories, necessitating effective surveillance and control programs to respond to these threats. One strategy to monitor virus activity involves collecting large numbers of mosquitoes from endemic sites and testing them for viral infection. In this article, we d...

Armstrong, Philip M.; Andreadis, Theodore G.; Finan, Shannon L.; Shepard, John J.; Thomas, Michael C.

2011-01-01

247

Phenoloxidase Activity Acts as a Mosquito Innate Immune Response against Infection with Semliki Forest Virus  

OpenAIRE

Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional PO cascade, which is activated by the bacterium Escherichia coli and the arbovirus Semliki Forest vir...

Rodriguez-andres, J.; Rani, S.; Varjak, M.; Chase-topping, M. E.; Beck, M. H.; Ferguson, M. C.; Schnettler, E.; Fragkoudis, R.; Barry, G.; Merits, A.; Fazakerley, J. K.; Strand, M. R.; Kohl, A.

2012-01-01

248

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

OpenAIRE

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 ...

Menger, David J.; Otieno, Bruno; Rijk, Marjolein; Mukabana, W. Richard; Loon, Joop Ja; Takken, Willem

2014-01-01

249

Effects of Manipulating Apoptosis on Sindbis Virus Infection of Aedes aegypti Mosquitoes  

OpenAIRE

Improved control of vector-borne diseases requires an understanding of the molecular factors that determine vector competence. Apoptosis has been shown to play a role in defense against viruses in insects and mammals. Although some observations suggest a correlation between apoptosis and resistance to arboviruses in mosquitoes, there is no direct evidence tying apoptosis to arbovirus vector competence. To determine whether apoptosis can influence arbovirus replication in mosquitoes, we manipu...

Wang, Hua; Gort, Taryn; Boyle, Daniel L.; Clem, Rollie J.

2012-01-01

250

Effect of Some Environmental Factors on the Predation Efficiency of the Mosquito; Toxorhynchites splendens (Diptera: Culicidae)  

OpenAIRE

The present work investigates the optimum conditions for the application of the predaceous mosquito, Toxorhynchites splendens as a biological control agent for other vector mosquito species in Egypt such as, Culex pipiens, Anopheles pharoensis and Aedes caspius under field conditions. The predation efficiency of T. splendens larvae was found to increase as the temperature increased. At 30-35C the predaceous larvae consumed greater numbers of both C. pipiens and Ae. Caspius than that of A. pha...

Mahmoud, Hanaa I.

2001-01-01

251

Modelling spatio-temporal population dynamics of mosquitoes, sources of nuisances and pathogen vectors  

OpenAIRE

Mosquitoes are sources of nuisances and vectors of major pathogens for humans and animals. Despite fighting facilities, controlling their populations remains a stake constained by a precise knowledge of their dynamics in space and time. This PhD aims at identifying biotic and abiotic factors affecting the spatio-temporal population dynamics of mosquitoes. An integrative modelling approach, linked to the use of a geographical informative system (GIS), statistical analysis and observational dat...

Cailly, Priscilla

2011-01-01

252

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

OpenAIRE

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 Nigeri...

Adebote, David A.; Oniye, Sonnie J.; Muhammed, Yunus A.

2008-01-01

253

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

OpenAIRE

Abstract 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...

Ndoen Ermi; Wild Clyde; Dale Pat; Sipe Neil; Dale Mike

2010-01-01

254

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

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Full Text Available Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cyclopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis Se hizo una prospección de copépodos en La Plata, Argentina, con los objetivos de caracterizar la comunidad local de copépodos larvívoros en sitios de cría de mosquitos, e identificar nuevas especies depredadoras de los mosquitos de contenedores artificiales Aedes aegypti y Culex pipiens. La diversidad de ciclopoides larvívoros fue máxima en charcos permanentes. Se examinó la depredación por sexos y edad, la selectividad por especies de mosquito, y la tasa de depredación diaria durante cinco días en Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus. Los copépodos hembra presentaron la capacidad depredadora más alta. No se encontró preferencia por alguna especie de mosquito. De acuerdo al potencial de depredación en general, los copépodos se ordenan así: D. uruguayensis < A. robustus < M. albidus < M. longisetus. También se evaluó la tolerancia a la desecación del hábitat y la capacidad de resistir en agua de contenedores artificiales. D. uruguayensis y A. robustus sobrevivieron en condiciones de sequía, pero D. uruguayensis presentó menor supervivencia en agua de floreros de cementerio. M. albidus no sobrevivió condiciones de sequía y no toleró el agua extraída de contenedores artificiales. Los ciclopoides neotropicales D. uruguayensis and A. robustus son buenos candidatos y merecen investigación ulterior como agentes de control biológico de mosquitos.

María C Tranchida

2009-12-01

255

Malaria Mosquitoes Attracted by Fatal Fungus  

OpenAIRE

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...

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

2013-01-01

256

Plasmodium ookinete-secreted chitinase and parasite penetration of the mosquito peritrophic matrix.  

Science.gov (United States)

Malaria transmission-blocking strategies aimed at disrupting parasite-mosquito interactions have the potential to make important contributions to global malaria control. It has been suggested that Plasmodium-secreted chitinase plays a crucial role in allowing the ookinete to initiate its invasion of the mosquito midgut, which suggests that this enzyme is a candidate target for blocking malaria transmission. In this review, the authors discuss Plasmodium chitinases from the molecular, biochemical and cell biology viewpoints. Future directions of study could involve developing strategies for interrupting the function of Plasmodium chitinases within the mosquito midgut, including transmission-blocking drugs or vaccines, or the development of chitinase-inhibitor-producing transgenic mosquitoes. PMID:11378031

Langer, R C; Vinetz, J M

2001-06-01

257

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

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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.

S.P. Singh

2014-03-01

258

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

CERN Document Server

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 ...

Genuer, Robin; Toussile, Wilson

2011-01-01

259

Transmission of malaria to mosquitoes blocked by bumped kinase inhibitors  

Science.gov (United States)

Effective control and eradication of malaria will require new tools to prevent transmission. Current antimalarial therapies targeting the asexual stage of Plasmodium do not prevent transmission of circulating gametocytes from infected humans to mosquitoes. Here, we describe a new class of transmission-blocking compounds, bumped kinase inhibitors (BKIs), which inhibit microgametocyte exflagellation. Oocyst formation and sporozoite production, necessary for transmission to mammals, were inhibited in mosquitoes fed on either BKI-1–treated human blood or mice treated with BKI-1. BKIs are hypothesized to act via inhibition of Plasmodium calcium-dependent protein kinase 4 and predicted to have little activity against mammalian kinases. Our data show that BKIs do not inhibit proliferation of mammalian cell lines and are well tolerated in mice. Used in combination with drugs active against asexual stages of Plasmodium, BKIs could prove an important tool for malaria control and eradication. PMID:22565309

Ojo, Kayode K.; Pfander, Claudia; Mueller, Natascha R.; Burstroem, Charlotte; Larson, Eric T.; Bryan, Cassie M.; Fox, Anna M.W.; Reid, Molly C.; Johnson, Steven M.; Murphy, Ryan C.; Kennedy, Mark; Mann, Henning; Leibly, David J.; Hewitt, Stephen N.; Verlinde, Christophe L.M.J.; Kappe, Stefan; Merritt, Ethan A.; Maly, Dustin J.; Billker, Oliver; Van Voorhis, Wesley C.

2012-01-01

260

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

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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.

John Alex N

2010-03-01

261

Measurement of landing mosquito density on humans.  

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In traditional vector surveillance systems, adult mosquito density and the rate of mosquito-human host contact are estimated from the mosquito numbers captured in mechanical traps. But the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental factors bias mosquito responses such that trapped mosquito numbers may be at variance with the numbers actually making human contact. As an alternative to mechanical traps, direct measurement of landing mosquito density enables real-time estimation of the mosquito-human-host-contact parameter. Based on this paradigm, we studied methods to measure mosquito landing responses to a human host. Our results showed: (a) an 18% difference (Pnumber of female Aedes albopictus (Skuse) making initial contact with the skin (9.11±0.74min(-1)) compared with the number remaining on the skin for 5s (7.42±0.69min(-1)); (b) an increase (P0.55) in the average number of Ae. albopictus landing on the arm (8.6±1.6min(-1)) compared with the leg (9.2±2.5min(-1)) of the same human subject; (d) differences among day-to-day landing patterns for the mosquito species we studied but measurable periodicity (P<0.05) in each case when daily patterns were averaged for four or more diel periods; and (e) an effect on landing mosquito density from air temperature (P<0.0001) for Ae. albopictus and Cx. nigripalpus and dew point temperature (P<0.0001) for Cx. quinquefasciatus. Results from this study were used to develop a procedure for safely and accurately measuring mosquito landing density on a human subject. PMID:24769003

Barnard, Donald R; Dickerson, Catherine Z; Murugan, Kadarkarai; Xue, Rui-De; Kline, Daniel L; Bernier, Ulrich R

2014-08-01

262

Can Wolbachia be used to control malaria?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Thomas, Walker; Luciano Andrade, Moreira.

2011-08-01

263

Can Wolbachia be used to control malaria?  

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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.

Thomas Walker

2011-08-01

264

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

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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.

N.M.Guruprasad

2013-09-01

265

Larvicidal activity of neem oil (Azadirachta indica formulation against mosquitoes  

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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.

Dua Virendra K

2009-06-01

266

Effect of rice husbandry on mosquito breeding at Mwea Rice Irrigation Scheme with reference to biocontrol strategies.  

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A study was carried out at Mwea Rice Irrigation Scheme, Kenya, to assess the impact of rice husbandry on mosquito breeding and identify indigenous biocontrol agents with potential for controlling mosquito breeding in the scheme. The study established a close relationship between the schedule of the farming practices (particularly the flooding phase) and mosquito breeding. Two groups of agents, entomopathogenic bacteria (Bacillus thuringiensis var. israelensis) and larvivorous fish, were identified. Laboratory evaluation of the agents produced encouraging results. The bacterial isolates showed broad-spectrum larvicidal potency against Anopheles, Culex and Aedes mosquito larvae and 2 of the fish species, Tilapia zilli and Oreochromis niloticus, demonstrated a strong predation for a mosquito larval diet. To facilitate their use in effective biocontrol strategies, the agents would require further evaluation under field conditions. PMID:8096871

Asimeng, E J; Mutinga, M J

1993-03-01

267

A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies  

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Full Text Available Abstract Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS, long lasting insecticide treated nets (LLINs and insecticide treated materials (ITMs. PubMed, (National Centre for Biotechnology Information (NCBI, U.S. National Library of Medicine, NIH, MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words “Mosquito coils” “Mosquito emanators” and “Spatial repellents”. It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose–response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP, which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control.

Ogoma Sheila B

2012-12-01

268

A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies.  

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Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control. PMID:23216844

Ogoma, Sheila B; Moore, Sarah J; Maia, Marta F

2012-01-01

269

Mosquito surveillance revealed lagged effects of mosquito abundance on mosquito-borne disease transmission: a retrospective study in Zhejiang, China.  

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Mosquito-borne diseases (MBDs) are still threats to public health in Zhejiang. In this study, the associations between the time-lagged mosquito capture data and MBDs incidence over five years were used to examine the potential effects of mosquito abundance on patterns of MBDs epidemiology in Zhejiang during 2008-2012. Light traps were used to collect adult mosquitoes at 11 cities. Correlation tests with and without time lag were performed to investigate the correlations between MBDs incidence rates and mosquito abundance by month. Selected MBDs consisted of Japanese encephalitis (JE), dengue fever (DF) and malaria. A Poisson regression analysis was performed by using a generalized estimating equations (GEE) approach, and the most parsimonious model was selected based on the quasi-likelihood based information criterion (QICu). We identified five mosquito species and the constituent ratio of Culex pipiens pallens, Culex tritaeniorhynchus, Aedes albopictus, Anopheles sinensis and Armigeres subalbatus was 66.73%, 21.47%, 6.72%, 2.83% and 2.25%, respectively. The correlation analysis without and with time lag showed that Culex mosquito abundance at a lag of 0 or 1 month was positively correlated with JE incidence during 2008-2012, Ae. albopictus abundance at a lag of 1 month was positively correlated with DF incidence in 2009, and An. sinensis abundance at a lag of 0-2 months was positively correlated with malaria incidence during 2008-2010. The Poisson regression analysis showed each 0.1 rise of monthly mosquito abundance corresponded to a positive increase of MBD cases for the period of 2008-2012. The rise of mosquito abundance with a lag of 0-2 months increased the risk of human MBDs infection in Zhejiang. Our study provides evidence that mosquito monitoring could be a useful early warning tool for the occurrence and transmission of MBDs. PMID:25393834

Guo, Song; Ling, Feng; Hou, Juan; Wang, Jinna; Fu, Guiming; Gong, Zhenyu

2014-01-01

270

PMI Activity TZ-1,2: IRS and LLIN: Integration of Methods and Insecticide Mode of Actions for Control of African Malaria Vector Mosquitoes  

OpenAIRE

Long lasting Insecticidal nets (LLINs) and indoor residual spraying (IRS) are the preferred techniques for malaria vector control in Africa, where their application has a proven contribution to the recent significant reductions in the burden of the disease. Even though both methods are commonly used together in the same households, evidence of improved malaria control due to the use of combinations as opposed to use of either method alone has been minimal and inconclusive.To measure the mode ...

Okumu, Fredros O.; Moore, Sarah J.

2012-01-01

271

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

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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.

Fukumitsu Yuki

2012-05-01

272

Transcriptome of the adult female malaria mosquito vector Anopheles albimanus  

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

Martínez-Barnetche Jesús

2012-05-01

273

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

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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.

Mnyone Ladslaus L

2010-08-01

274

Study of mosquito fauna in rice ecosystems around Hanoi, Northern Vietnam.  

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Species of the Culex vishnui subgroup, Cx. fuscocephala and Cx. gelidus, which are known Japanese encephalitis (JE) vectors, are distributed in rice agroecosystems in Asian countries. Hence, although ecological studies of rice agroecosystems in northern Vietnam are necessary, very few integrated studies of breeding habitats of mosquitoes, including JE vectors, have been conducted. We carried out a field study and investigated the mosquito fauna in six rice production areas in northern Vietnam during the rainy and dry seasons of 2009. Mosquitoes and potential mosquito predators were collected from aquatic habitats by using larval dippers. We collected 1780 Culex individuals (including 254 Cx. tritaeniorhynchus; 113 Cx. vishnui, 58 Cx. vishnui complex, consisting of Cx. vishnui and Cx. pseudovishnui; 12 Cx. gelidus; 1 Cx. bitaeniorhynchus; and 1 Cx. fuscocephala), 148 Anopheles individuals (including 5 An. vagus), 1 Mansonia annulifera, and 1 Mimomyia chamberlaini during the rainy season. During the dry season, we collected 176 Culex individuals (including 33 Cx. vishnui, 24 Cx. tritaeniorhynchus, 8 Cx. vishnui complex, and 1 Cx. gelidus) and 186 Anopheles individuals (including 9 An. tessellatus, 2 An. kochi, and 2 An. barbumbrosus). We found mosquitoes in all aquatic habitats, namely, rice fields, ditches, ponds, wetlands, irrigation canals, and rice nurseries, and Cx. tritaeniorhynchus and Cx. vishnui complex were found in all the above six areas. Heteroptera such as Micronecta, Veliidae, and Pleidae were abundant and widely distributed in both the seasons. The abundance of mosquito larvae was higher in the rice fields, ditches, and ponds during the rainy season than during the dry season. Cx. tritaeniorhynchus, Cx. vishnui complex, Cx. fuscocephala, and Cx. gelidus were abundant in rice agroecosystems (rice fields, ditches, ponds, and wetlands) in northern Vietnam, and their abundance was high during the rainy season. These findings deepen our understanding of mosquito ecology and strengthen mosquito control strategies to be applied in rice ecosystems Vietnam in the future. PMID:25445747

Ohba, Shin-Ya; Van Soai, Nguyen; Van Anh, Dinh Thi; Nguyen, Yen T; Takagi, Masahiro

2015-02-01

275

Competition for amino acids between Wolbachia and the mosquito host, Aedes aegypti.  

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The endosymbiont Wolbachia represents a promising method of dengue control, as it reduces the ability of the primary vector, the mosquito Aedes aegypti, to transmit viruses. When mosquitoes infected with the virulent Wolbachia strain wMelPop are fed non-human blood, there is a drastic reduction in mosquito fecundity and egg viability. Wolbachia has a reduced genome and is clearly dependent on its host for a wide range of nutritional needs. The fitness defects seen in wMelPop-infected A. aegypti could be explained by competition between the mosquito and the symbiont for essential blood meal nutrients, the profiles of which are suboptimal in non-human blood. Here, we examine cholesterol and amino acids as candidate molecules for competition, as they have critical roles in egg structural development and are known to vary between blood sources. We found that Wolbachia infection reduces total cholesterol levels in mosquitoes by 15-25%. We then showed that cholesterol supplementation of a rat blood meal did not improve fecundity or egg viability deficits. Conversely, amino acid supplementation of sucrose before and after a sheep blood meal led to statistically significant increases in fecundity of approximately 15-20 eggs per female and egg viability of 30-40%. This mosquito system provides the first empirical evidence of competition between Wolbachia and a host over amino acids and may suggest a general feature of Wolbachia-insect associations. These competitive processes could affect many aspects of host physiology and potentially mosquito fitness, a key concern for Wolbachia-based mosquito biocontrol. PMID:24337107

Caragata, Eric P; Rancès, Edwige; O'Neill, Scott L; McGraw, Elizabeth A

2014-01-01

276

Screening of Rubiaceae and Apocynaceae extracts for mosquito larvicidal potential.  

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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

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

2015-01-01

277

Bioassays for Culex (Diptera: Culicidae) mosquito oviposition attractants and stimulants.  

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Bioassay methods for mosquito oviposition attractants and stimulants were developed and compared, using Culex tarsalis Coq. gravid females as test insects, and distilled water, dyed water, or Bermuda grass infusions as the test stimuli. Bioassays with sticky screens covering jars containing volatile test stimuli or with colorless and odorless Triton X100 surfactant in the aqueous oviposition medium demonstrated that gravid mosquitoes were attracted to distilled water, with the attraction increased by the addition of dye, grass infusion, or the steam distillate of grass infusion to the water. A variation of the sticky screen bioassay was used to demonstrate that the grass infusion also contained oviposition stimulants. A forced oviposition bioassay was minimally useful, because it failed to discriminate between a solution known to contain oviposition stimulants and a distilled-water control. Overall, the bioassays developed can be used to distinguish between oviposition attractants and stimulants, a distinction that cannot be made by simply counting egg rafts. PMID:7650709

Isoe, J; Millar, J G; Beehler, J W

1995-07-01

278

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

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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. Experimental 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. PMID:25410994

Irish, Seth R

2014-11-01

279

Conserved molecular mechanism for the stage specificity of the mosquito vitellogenic response to ecdysone.  

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In the mosquito Aedes aegypti, the adult female becomes competent for a vitellogenic response to ecdysone after previtellogenic development. Here, we show that betaFTZ-F1, the nuclear receptor implicated as a competence factor for stage-specific responses to ecdysone during Drosophila metamorphosis, serves a similar function during mosquito vitellogenesis. AaFTZ-F1 is expressed highly in the mosquito fat body during pre- and postvitellogenic periods when ecdysteroid titers are low. The mosquito AaFTZ-F1 transcript nearly disappears in mid-vitellogenesis when ecdysteroid titers are high. An expression peak of HR3, a nuclear receptor implicated in the activation of betaFTZ-F1 in Drosophila, precedes each rise in mosquito FTZ-F1 expression. In in vitro fat body culture, AaFTZ-F1 expression is inhibited by 20-hydroxyecdysone (20E) and superactivated by its withdrawal. Following in vitro AaFTZ-F1 superactivation, a secondary 20E challenge results in superinduction of the early AaE75 gene and the late target VCP gene. Electrophoretic mobility-shift assays show that the onset of ecdysone-response competence in the mosquito fat body is correlated with the appearance of the functional AaFTZ-F1 protein at the end of the previtellogenic development. These findings suggest that a conserved molecular mechanism for controlling stage specificity is reiteratively used during metamorphic and reproductive responses to ecdysone. PMID:10898964

Li, C; Kapitskaya, M Z; Zhu, J; Miura, K; Segraves, W; Raikhel, A S

2000-08-01

280

Detection of infectious virus from field-collected mosquitoes by vero cell culture assay.  

Science.gov (United States)

Mosquitoes transmit a number of distinct viruses including important human pathogens such as West Nile virus, dengue virus, and chickungunya virus. Many of these viruses have intensified in their endemic ranges and expanded to new territories, necessitating effective surveillance and control programs to respond to these threats. One strategy to monitor virus activity involves collecting large numbers of mosquitoes from endemic sites and testing them for viral infection. In this article, we describe how to handle, process, and screen field-collected mosquitoes for infectious virus by Vero cell culture assay. Mosquitoes are sorted by trap location and species, and grouped into pools containing ?50 individuals. Pooled specimens are homogenized in buffered saline using a mixer-mill and the aqueous phase is inoculated onto confluent Vero cell cultures (Clone E6). Cell cultures are monitored for cytopathic effect from days 3-7 post-inoculation and any viruses grown in cell culture are identified by the appropriate diagnostic assays. By utilizing this approach, we have isolated 9 different viruses from mosquitoes collected in Connecticut, USA, and among these, 5 are known to cause human disease. Three of these viruses (West Nile virus, Potosi virus, and La Crosse virus) represent new records for North America or the New England region since 1999. The ability to detect a wide diversity of viruses is critical to monitoring both established and newly emerging viruses in the mosquito population. PMID:21694689

Armstrong, Philip M; Andreadis, Theodore G; Finan, Shannon L; Shepard, John J; Thomas, Michael C

2011-01-01

281

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Seth R, Irish.

2014-11-01

282

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

283

Population dynamics of mosquitoes and malaria vector incrimination in district Charsadda, Khyber Pakhtunkhwa (KP) Pakistan.  

Science.gov (United States)

This study aimed to obtain updated information on mosquito diversity and malaria vector incrimination in Charsadda Khyber Pakhtunkhwa to help in devising effective control and preventive measures in the area. Monthly survey of indoor mosquitoes for one year was carried out in three villages, Dhaki Totaqi and Mathra. Female Anopheline were used to detect Circumsporozoites protein (CSP) using Enzyme Linked Immunosorbent Assay. Among 17 mosquito species, Culex quinquefasciatus, Anopheles splendidus, Anopheles stephensi, Anopheles fluviatilus, Anopheles culicifacies and Culex tritaeniorhynchus were predominant. Dhaki village had the highest mosquito species diversity (1.015) and similar species richness (0.7) and evenness (0.5) with village Mathra. Slide positivity rate (SPR) shows that the rate of malaria transmission increases with mosquito population. Four anopheline species i.e. A. stephensi, A. fluviatilis, A. splendidus, and A. culicifacies were CSP positive. The CSP rate was 0.8%, where two specimens of A. splendidus and one of A. fluviatilus were positive for Plasmodium falciparum, Plasmodium vivax was represented by two variants 210 and 247. Among the 20 CSP positive specimens, variant 210 was found in 12 (one belonging to A. culicifacies, two each of A. stephensi and A. fluviatilus, seven specimens of A. splendidus) and 247 in 8 specimens (two of A. stephensi, three each of A. fluviatilus and A. splendidus). The number of infected mosquitoes collected from animal sheds was higher (15) though non-significant (P>0.05) than that from bedrooms (8). PMID:25255965

Ali, Naheed; Noreen, Shumaila; Khan, Khalid; Wahid, Sobia

2014-09-22

284

[Effectiveness of aerial application of VectoBac G larvicide granules against mosquitoes in the Olomouc region in spring 2006].  

Science.gov (United States)

In the spring 2006, a flood emergency occurred in the Olomouc region after a rapid snow thaw, with the formation of multiple periodic pools and overflows persisting for long periods. In the floodplain forests, as expected, mass occurrence of adult mosquitoes was observed, infesting the nearby villages. The mosquito emergency continued until August and mosquitoes of both the spring species, in particular, Ochlerotatus cantans, and summer species were implicated in it. To control this emergency, aerial application of VectoBac G larvicide granules based on Bacillus thuringiensis var. israelensis (BTI) at a dose of 6.4 kg/ha was used for the first time in the Olomouc region. Its efficacy was close to 100 % for the treated water areas. The effect was clearly evident in the communities situated in the vicinity of the treated breeding grounds. Nevertheless, not all breeding grounds and blind stream meanders could be treated aerially. As a result, mosquitoes from the untreated breeding grounds caused an emergency in the nearby communities where insecticide aerosols had to be applied on a large scale, even repeatedly in some cases. The treatment of the mosquito breeding grounds with BTI based larvicide granules proved to be an effective and fully selective approach to controlling mosquitoes. Although the technology is exacting and requires professional and organizational skills, it is expected that, in the Czech Republic, this environmentally friendly approach to mosquito control will replace the large scale use of non-selective chemical aerosol insecticides. The public health protection, administrative and legislative authorities should be active in promoting the use of specific BTI based larvicides for the treatment of mosquito breeding grounds, even if located in protected areas, whenever it is needed for mosquito control in emergencies. PMID:17593805

Chmela, J; Mazánek, L; Nakládal, Z; Pesáková, L; Halirová, R

2007-04-01

285

Dynamics of Bacillus thuringiensis var. israelensis and Lysinibacillus sphaericus spores in urban catch basins after simultaneous application against mosquito larvae  

OpenAIRE

Bacillus thuringiensis var. israelensis (Bti) and Lysinibacillus sphaericus (Lsph) are extensively used in mosquito control programs. These biocides are the active ingredients of a commercial larvicide. Quantitative data on the fate of both Bti and Lsph applied together for the control of mosquitoes in urban drainage structures such as catch basins are lacking. We evaluated the dynamics and persistence of Bti and Lsph spores released through their concomitant application in urban catch basins...

Guidi, V.; Lehner, A.; Lu?thy, P.; Tonolla, M.

2013-01-01

286

Historical applications of induced sterilisation in field populations of mosquitoes  

Directory of Open Access Journals (Sweden)

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

Knols Bart GJ

2009-11-01

287

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

OpenAIRE

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...

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

288

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)

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.

Chabi Joseph

2010-02-01

289

Studies on the effect of translocation of chemical insecticides in Eicchornia host plant on Mansonia mosquitos--a potential control method.  

Science.gov (United States)

A novel method for the control of Mansonia larvae was developed and tested. In this method, foliar absorption and translocation of a chemical insecticide, monocrotophos, a known systemic insecticide was studied in the Eicchornia plant. Acetone solution of the insecticide was painted onto leaves of the plant. At daily intervals, stems were severed and divided into equal sections which were introduced into bowls. Larvae of Aedes aegypti were tested for the presence of monocrotophos. It was found that translocation of the insecticide occurred at different rates in the stems and in some plants the chemical was also released into the surrounding water. Based on these results, 2 insecticides namely, monocrotophos and temephos were painted onto leaves of the host plant and their translocation to the root and water environment was examined by testing with Mansonia and Aedes aegypti larvae. The results again confirmed the translocation process and it was found that the insecticides were secreted into the surrounding water, thereby killing the larvae. However, in leaves painted with permethrin (synthetic pyrethroid) or flufenoxuron (chitin synthesis inhibitor), such a process was not detected. The potential of this new concept in Mansonia larval control is examined. PMID:7526473

Lee, H L; Singh, K I

1993-01-01

290

Can mosquitoes fly in the rain?  

CERN Document Server

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.

Dickerson, Andrew; Madhavan, Nihar; Hu, David

2011-01-01

291

Mosquito immune defenses against Plasmodium infection.  

Science.gov (United States)

The causative agent of malaria, Plasmodium, has to undergo complex developmental transitions and survive attacks from the mosquito's innate immune system to achieve transmission from one host to another through the vector. Here we discuss recent findings on the role of the mosquito's innate immune signaling pathways in preventing infection by the Plasmodium parasite, the identification and mechanistic description of novel anti-parasite molecules, the role that natural bacteria harbored in the mosquito midgut might play in this immune defense and the crucial parasite and vector molecules that mediate midgut infection. PMID:20026176

Cirimotich, Chris M; Dong, Yuemei; Garver, Lindsey S; Sim, Shuzhen; Dimopoulos, George

2010-04-01

292

Larvicidal and phytochemical properties of Callistemon rigidus R. Br. (Myrtaceae) leaf solvent extracts against three vector mosquitoes  

OpenAIRE

Background & objectives: Due to ever-growing insecticide resistance in mosquito vectors and environmental contamination by synthetic insecticides, plants may be a source of alternative agents for mosquito control. Therefore, the present investigation involved the determination of larvicidal and phytochemical properties of Callistemon rigidus leaf extracts against Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. Methods: The standard pr...

Danga Yinyang Simon Pierre; Esimone Charles Okechukwu; Nukenine Elias Nchiwan

2014-01-01

293

Mosquito embryos and eggs: polarity and terminology of chorionic layers.  

Science.gov (United States)

The development of genetically modified vectors refractory to parasites is seen as a promising strategy in the future control of endemic diseases such as malaria. Nevertheless, knowledge of mosquito embryogenesis, a pre-requisite to the establishment of transgenic individuals, has been presently neglected. We have here studied the eggs from two neotropical malaria vectors. Eggs from Anopheles (Nyssorhynchus) albitarsis and Anopheles (Nyssorhynchus) aquasalis were analyzed by laser scanning microscopy and scanning electron microscopy and compared to those of Drosophila melanogaster. We verified basic conflicting data such as mosquito egg polarity and ultrastructure of eggshell layers. A 180 degrees rotation movement of the mosquito embryo along its longitudinal axis, a phenomenon not conserved among all Diptera, was confirmed. This early event is not taken into account by several present groups, leading to a non-consensual assignment of eggshell dorsal and ventral poles. Since embryo and egg polarities, defined during oogenesis, are the same, we propose to consider the flattened egg side as the dorsal one. The structure of Anopheles eggshell was also examined. Embryos are covered by a smooth endochorion or inner chorion layer. Outside this coat lies the compound exochorion or outer chorion layer, assembled by a thin basal lamellar layer and external tubercles. The terminology related to eggshell layers is discussed. PMID:12770300

Valle, D; Monnerat, A T.; Soares, M J.; Rosa-Freitas, M G.; Pelajo-Machado, M; Vale, B S.; Lenzi, H L.; Galler, R; Lima, J B.P.

1999-08-01

294

A rationale to design longer lasting mosquito repellents.  

Science.gov (United States)

Mosquito repellents represent a cleaner and safer alternative for population control and reduce the diseases they carry in large areas of the world. Recently, research has been focused on repellents of natural origins, both crude essential oils and their main constituents. We have observed that, although a large number of compounds can be efficiently used as mosquito repellents, their efficacy is never higher than those of commercial products DEET and Icaridin. Reasoning that probably specific and exceptionally active repellents might not exist, we focused our research on products that could provide longer protection times with respect to current commercial formulations while being used at lower concentrations. Based on the structure of menthone, a moderate natural repellent, we designed and synthesised some cyclic ketals that, because of their reduced volatility, could be effective for longer periods. In particular, a 1% solution of one of such derivatives can still reduce mosquito bites by 90% after 2 h, while DEET provides the same performance only for 15 min, when used at the same concentration. The approach we illustrate can be applied to other compounds and other systems and offers the additional advantage that derivatives of reduced volatility are also endowed with weaker odours. PMID:24599300

Iovinella, Immacolata; Pelosi, Paolo; Conti, Barbara

2014-05-01

295

Susceptibility of adult mosquitoes to insecticides in aqueous sucrose baits.  

Science.gov (United States)

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

Allan, Sandra A

2011-06-01

296

Evidence of anopheline mosquito resistance to agrochemicals in northern Thailand.  

Science.gov (United States)

The objective of this study was to assess insecticide resistance in anopheline mosquito populations in agroecosystems with high and low insecticide use in a malaria endemic area in Chiang Mai province in northern Thailand. Anopheline mosquitoes were collected in May and June 2004 from two locations with different agricultural insecticide intensity (HIGH and LOW), but similar in vector control strategies. The F1-generation of Anopheles maculatus s.s. and An. sawadwongporni were subjected to diagnostic doses of methyl parathion (MeP) and cypermethrin (Cyp), both commonly used insecticides in fruit orchards in Thailand. An. minimus A from the HIGH location was subjected to diagnostic doses to Cyp. CDC bottle bioassays were used to determine insecticide susceptibility. Time-mortality data were subjected to Probit analyses to estimate lethal time values (LT50 and LT90). Lethal time ratios (LTR) were computed to determine differences in lethal time response between populations from HIGH and LOW locations. The mortality of An. maculatus to MeP was 74% and 92% in the HIGH and LOW locations, respectively. The corresponding figures for An. sawadwongporni were 94% and 99%. There was no indication of resistance to Cyp for all species tested in either location. The LT90 and LT50 values of An. maculatus s.s. subjected to diagnostic doses of MeP were significantly different between locations (p<0.05). Reduced susceptibility to MeP in mosquito populations in the HIGH location is caused by intensive agricultural pest control and not by vector control activities, because organophosphates have never been used for vector control in the area. Our results indicate that there are still susceptible anopheline populations to pyrethroids, which is consistent with other research from the region. Therefore, there is presently no direct threat to vector control. However increased use of pyrethroids in agriculture may cause problems for future vector control. PMID:16438202

Overgaard, Hans J; Sandve, Simen R; Suwonkerd, Wannapa

2005-01-01

297

Toxicological assays for testing effects of an epigenetic drug on development, fecundity and survivorship of malaria mosquitoes.  

Science.gov (United States)

Insecticidal resistance poses a major problem for malaria control programs. Mosquitoes adapt to a wide range of changes in the environment quickly, making malaria control an omnipresent problem in tropical countries. The emergence of insecticide resistant populations warrants the exploration of novel drug target pathways and compounds for vector mosquito control. Epigenetic drugs are well established in cancer research, however not much is known about their effects on insects. This study provides a simple protocol for examining the toxicological effects of 3-Deazaneplanocin A (DZNep), an experimental epigenetic drug for cancer therapy, on the malaria vector, Anopheles gambiae. A concentration-dependent increase in mortality and decrease in size was observed in immature mosquitoes exposed to DZNep, whereas the compound reduced the fecundity of adult mosquitoes relative to control treatments. In addition, there was a drug-dependent decrease in S-adenosylhomocysteine (SAH) hydrolase activity in mosquitoes following exposure to DZNep relative to control treatments. These protocols provide the researcher with a simple, step-by-step procedure to assess multiple toxicological endpoints for an experimental drug and, in turn, demonstrate a unique multi-prong approach for exploring the toxicological effects of water-soluble epigenetic drugs or compounds of interest against vector mosquitoes and other insects. PMID:25650701

Sharma, Atashi; Anderson, Troy D; Sharakhov, Igor V

2015-01-01

298

A new larval tray and rack system for improved mosquito mass rearing.  

Science.gov (United States)

The requirement for efficient mosquito mass rearing technology has been one of the major obstacles preventing the large scale application of the Sterile Insect Technique against mosquitoes. At the Food and Agriculture Organization/International Atomic Energy Agency (FAO/ IAEA) Insect Pest Control Laboratories we developed a larval rearing unit based on the use of a stainless steel rack that operates 50 thermoformed ABS plastic trays and is expected to be able to successfully rear 140,000-175,000 Anopheles arabiensis (Patton) adult mosquitoes per rack. The mechanized rearing unit is simple to handle, maintains minimal water temperature variation and negligible water evaporation and allows normal larval development. The mosquito mass-rearing tray was designed to provide a large surface area of shallow water that would closely mimic natural breeding sites. The trays stack into a dedicated rack structure and filling and draining were easily performed. The close stacking of the trays in the rack and the possibility to tightly line up several racks makes this rearing unit a valid solution for maximal use of the space thus reducing construction, heating, and cooling costs. The low amount of labor required to operate the system also reduces labor costs that represent one of the main expenditures in any mass rearing facility operation. Preliminary experiments performed on Aedes albopictus (Skuse) also confirm the possibility of successfully extending the use of this technology to other mosquito species. Our larval rearing unit could enhance any mosquito control strategy in which large-scale releases of mosquitoes are needed to suppress or replace natural populations. PMID:22679867

Balestrino, F; Benedict, M Q; Gilles, J R L

2012-05-01

299

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

Science.gov (United States)

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

Arbaoui, A A; Chua, T H

2014-03-01

300

Specific detection of the floodwater mosquitoes Aedes sticticus and Aedes vexans DNA in predatory diving beetles.  

Science.gov (United States)

Floodwater mosquitoes (Diptera: Culicidae) are associated with periodically flooded wet meadows, marshes, and swamps in floodplains of major rivers worldwide, and their larvae are abundant in the shallow parts of flooded areas. The nuisance caused by the blood-seeking adult female mosquitoes motivates mosquito control. Larviciding with Bacillus thuringiensis israelensis is considered the most environmentally safe method. However, some concern has been raised whether aquatic predatory insects could be indirectly affected by this reduction in a potential vital prey. Top predators in the temporary wetlands in the River Dalälven floodplains are diving beetles (Coleoptera: Dytiscidae), and Aedes sticticus and Ae. vexans are the target species for mosquito control. For detailed studies on this aquatic predator-prey system, we developed a polymerase chain reaction (PCR) assay for detection of mosquito DNA in the guts of medium-sized diving beetles. Primers were designed for amplifying short mitochondrial DNA fragments of the cytochrome C oxidase subunit I (COI) gene in Ae. sticticus and Ae. vexans, respectively. Primer specificity was confirmed and half-life detectability of Ae. sticticus DNA in diving beetle guts was derived from a feeding and digestion experiment. The Ae. sticticus DNA within diving beetle guts was detected up to 12 h postfeeding, and half-life detectability was estimated to 5.6 h. In addition, field caught diving beetles were screened for Ae. sticticus and Ae. vexans DNA and in 14% of the diving beetles one or both mosquito species were detected, showing that these mosquito species are utilized as food by the diving beetles. PMID:24895318

Vinnersten, Thomas Z Persson; Halvarsson, Peter; Lundström, Jan O

2014-06-01

301

Using a New Odour-Baited Device to Explore Options for Luring and Killing Outdoor-Biting Malaria Vectors: A Report on Design and Field Evaluation of the Mosquito Landing Box.  

OpenAIRE

Mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. Outdoor tools may therefore complement current indoor measures and improve control. We developed and evaluated a prototype mosquito control device, the 'Mosquito Landing Box' (MLB), which is baited with human odours and treated with mosquitocidal agents. The findings are used to explore technical options and challe...

Matowo, Nancy S.; Moore, Jason; Mapua, Salum; Madumla, Edith P.; Moshi, Irene R.; Kaindoa, Emanuel W.; Mwangungulu, Stephen P.; Kavishe, Deogratius R.; Sumaye, Robert D.; Lwetoijera, Dickson W.; Okumu, Fredros O.

2013-01-01

302

Mosquito larvicidal activity of active constituent derived from Chamaecyparis obtusa leaves against 3 mosquito species.  

Science.gov (United States)

Mosqutio larvicidal activity of Chamaecyparis obtusa leaf-derived materials against the 4th-stage larvae of Aedes aegypti (L.), Ochlerotatus togoi (Theobald), and Culex pipiens pallens (Coquillett) was examined in the laboratory. A crude methanol extract of C. obtusa leaves was found to be active (percent mortality rough) against the 3 species larvae; the hexane fraction of the methanol extract showed a strong larvicidal activity (100% mortality) at 100 ppm. The bioactive component in the C. obtusa leaf extract was characterized as beta-thujaplicin by spectroscopic analyses. The LC50 value of beta-thujaplicin was 2.91, 2.60, and 1.33 ppm against Ae. aegypti, Oc. togoi, and Cx. pipiens pallens larvae. This naturally occurring C. obtusa leaves-derived compound merits further study as a potential mosquito larval control agent or lead compound. PMID:16506565

Jang, Young-Su; Jeon, Ju-Hyun; Lee, Hoi-Seon

2005-12-01

303

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

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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.

Malcolm Colin A

2009-06-01

304

Slow Death by Many Mosquito Bites  

CERN Document Server

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.

Redner, S

2014-01-01

305

Population dynamics of indoor sampled mosquitoes and their implication in disease transmission in Abeokuta, south-western Nigeria  

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Full Text Available Background & objectives: A longitudinal study was carried out to investigate the speciescomposition, seasonal abundance, parity and feeding preference of indoor sampled mosquitoes inAbeokuta, south-western Nigeria.Methods: The mosquitoes were sampled weekly from five stratified locations using Center forDisease Control (CDC light-traps between August 2005 and July 2006. The mosquitoes wereexamined for abdominal condition and dissected for age composition. Microscopic and precipitintechniques were also employed for the determination of host blood source.Results: A total of 2969 mosquitoes which belong to 10 species of mosquitoes were collectedduring the study period. Mansonia africana (35.65% constituted the most abundant species followedby Culex quinquefasciatus (32.23% and Anopheles gambiae complex (13.52%. Other species indecreasing order of abundance were Coquilletidia maculipennis (8.2%, Aedes albopictus (5.9%,Ae. aegypti (1.93%, M. uniformis (1.81%, Cx. duttoni (0.25%, Cx. tigripes (0.25% and An.funestus (0.25%. Seasonal abundance revealed a significant difference (p <0.05 in the populationof mosquito vectors collected during the wet season as compared to the dry season and theirabundance was positively correlated with rainfall. The results showed that the majority of thevector species collected were unfed and nulliparous. Moreover, the blood meal test was positive forhuman blood.Conclusion: The preponderance of mosquitoes observed in the study is of public health concernsince they serve as vectors of most tropical diseases including malaria

M.A. Adeleke, C.F. Mafiana, A.B. Idowu, S.O. Sam-Wobo & O.A. Idowu

2010-03-01

306

Oviposition strategies of temporary pool mosquitoes in relation to weather, tidal regime and land use in a temperate wetland.  

Science.gov (United States)

Wetlands have traditionally been associated with harbouring mosquitoes, a well-known nuisance and vectors of diseases. Within mosquito life cycle, oviposition is a determinant event by shaping their individual fitness and vectorial capacity. The study was conducted in one of the main temperate wetlands in South America. We used Generalized Linear Models to study the relation between temperature, precipitation, tidal regime, land use, microenvironment, and the occurrence of floodwater (Ochlerotatus and Psorophora spp.) and raft-laying (Culex and Uranotaenia spp.) mosquitoes using temporary pools as larval habitats. Pool occurrence was negatively associated with temperature, and positively related to precipitation and high tides. As regards the land use, it was lowest in domestic areas and plantations, intermediate in secondary forests, and highest in marshes. Each oviposition strategy was best modelled as a function of different environmental factors. The occurrence of floodwater mosquitoes was positively associated with high cumulative precipitation and low tide records. Raft-laying mosquitoes were related to low temperature records, while the effect of flooding varied with the land use. In view of these results, physical (water inputs and movement), chemical, and biological (egg and larval flushing, and predatory interactions) considerations are given to provide insight in the oviposition patterns of mosquitoes occurring in this complex wetland. We finally propose the generation of a tidal flow as a control measure against floodwater mosquitoes, which are the most anthropophilic in the study area. PMID:22647341

Cardo, M V; Vezzani, D; Carbajo, A E

2012-12-01

307

Mosquito immune defenses against Plasmodium infection  

OpenAIRE

The causative agent of malaria, Plasmodium, has to undergo complex developmental transitions and survive attacks from the mosquito's innate immune system to achieve transmission from one host to another through the vector. Here we discuss recent findings on the role of the mosquito's innate immune signaling pathways in preventing infection by the Plasmodium parasite, the identification and mechanistic description of novel anti-parasite molecules, the role that natural bacteria harbored in the...

Cirimotich, Chris M.; Dong, Yuemei; Garver, Lindsey S.; Sim, Shuzhen; Dimopoulos, George

2010-01-01

308

Potential of the bush mint, Hyptis suaveolens essential oil for personal protection against mosquito biting.  

Science.gov (United States)

We studied the potential of the essential oil extract from the bush mint, Hyptis suaveolens, for use against mosquito biting under both laboratory and field conditions. In the laboratory, the repellency of various concentrations (1-6%) of the essential oil was assessed against Anopheles gambiae, based on a 15-min landing and biting on treated forearms of volunteers. In the laboratory, the percentage of mosquitoes landing on the forearm was 42, 33, 23, 23, 9, and 2 for 1%, 2%, 3%, 4%, 5%, and 6% essential oil concentration, respectively; and 92 and 91 for the solvent (isopropanol) and untreated control, respectively. The percentage of mosquitoes taking a blood meal was 22, 12, 13, 12, 5, and 3 for 1%, 2%, 3%, 4%, 5%, and 6% essential oil, respectively; and 52 and 51 for the solvent and control, respectively. In the field, the 6% essential oil repelled all mosquitoes immediately postapplication; this activity declined to 75% after 5 h. The repellent action of the 8% essential oil concentration was higher, 97% after 5 h. Based on these data, the essential oil of H. suaveolens appears to be a good candidate for use in the integrated management of mosquito vectors of disease. PMID:22533079

Abagli, Ayaba Z; Alavo, Thiery B C; Avlessi, Félicien; Moudachirou, Mansourou

2012-03-01

309

Mosquito biting behavior: statistical power and sources of variation in toxicity and repellent bioassays.  

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Compounds thought to be effective against mosquitoes as either 'insecticides' or 'repellents' have recently been shown to contain properties of both, or possess other behavior-modifying actions. Prompted in part by these reports, we conducted posterior analyses of our data to examine some interrelated statistical issues inherent in our bioassay system. Using a modified K&D module, the responses of over 25,000 adult Aedes aegypti (L.) females exposed to either alphacypermethrin or DEET were compared with the responses of mosquitoes exposed to untreated controls for toxicity and biting (alphacypermethrin) or biting alone (DEET). Our analyses indicated that; (1) our bioassay system has more statistical power to determine a compound's toxicity than its repellent qualities, (2) day-to-day variability is large and needs to be accommodated in analyses; there are other, potentially even larger sources of variability (e.g., mosquito heterogeneity) which invalidate statistical tests that are based on the assumption of binomially or multinomially distributed data (e.g., chi2 tests), and (3) unlike biting mosquitoes exposed to DEET, the proportions of biting mosquitoes exposed to alphacypermethrin are unrelated to the proportions of concurrently tested biting controls, even after adjusting for daily variation in toxicity. Thus, there is a clear behavioral indicator in this bioassay system that the 'repellency' of DEET (a presumed repellent) differs in a fundamental way from that of alphacypermethrin (a presumed toxicant), which may allow the differentiation between classes of compounds based on biting behavior alone. PMID:20380300

Kramer, Matthew; Feldlaufer, Mark F; Chauhan, Kamlesh R

2010-03-01

310

Repelentes electrónicos contra mosquitos: propaganda y realidad  

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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.

Frank Coro

1998-08-01

311

Repelentes electrónicos contra mosquitos: propaganda y realidad  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish 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. Abstract in english 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.

Frank, Coro; Silvia, Suárez.

1998-08-01

312

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

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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.

R. Weterings

2014-12-01

313

Mosquito Repellent Activity and Phytochemical Characterization of Essential Oils From Striga hermonthica, Hyptis spicigera and Ocimum basilicum Leaf Extracts  

OpenAIRE

The main aim of this study is to screen the phytochemicals and compare the mosquito repellent activities of essential oils from Hyptis spicigera, Striga hermonthica and Ocimum basilicum (Basil) against Anopheles gambiae and Culex quinquefasciatus under laboratory conditions. The global threat of malaria to human race and the need to control its advances is on the focus. Mosquito is the target being the primary host in the spread of malaria. Alkaloids, saponnins, steroids, tannins and terpenoi...

Gabi Baba; Lawal, A. O.; Sharif, Hauwa B.

2012-01-01

314

Protection from UV-B damage of mosquito larvicidal toxins from Bacillus thuringiensis subsp. israelensis expressed in Anabaena PCC 7120.  

Science.gov (United States)

A transgenic strain of the nitrogen-fixing filamentous cyanobacterium Anabaena PCC 7120 protected expressed delta-endotoxin proteins of Bacillus thuringiensis subsp. israelensis from damage inflicted by UV-B, a sunlight component that penetrates Earth's ozone layer. This organism, which serves as a food source to mosquito larvae and could multiply in their breeding sites, may solve the environment-imposed limitations of B. thuringiensis subsp. israelensis as a mosquito biological control agent. PMID:12177745

Manasherob, Robert; Ben-Dov, Eitan; Xiaoqiang, Wu; Boussiba, Sammy; Zaritsky, Arieh

2002-09-01

315

Larval Habitat Characteristics of the Genus Anopheles (Diptera: Culicidae) and a Checklist of Mosquitoes in Guilan Province, Northern Iran  

OpenAIRE

Background: Ecological data are important in the vector control management of mosquitoes. There is scattered pub­lished information about the larval habitat characteristics and ecology of the genus Anopheles (Diptera: Culicidae) in Iran and most of available data is in relation to malaria vectors in southern Iran.Methods: This cross sectional investigation was carried out to study the mosquito fauna and ecology in Guilan Province, northern Iran, during April–December 2000. Larvae were coll...

Azari-hamidian, S.

2011-01-01

316

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

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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.

Yang Guojun

2012-06-01

317

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

Science.gov (United States)

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

Das, P K; Sivagnaname, N; Amalraj, D Dominic

2006-06-01

318

Preliminary evaluation of mosquito larvicidal efficacy of plant extracts  

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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

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

2007-06-01

319

Mosquito larvicidal and antimicrobial activity of protein of Solanum villosum leaves  

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Full Text Available Abstract Background Mosquitoes are associated with the transmission of malaria, dengue, Japanese encephalitis, filariasis and other viral diseases throughout the globe, apart from being a nuisance pest. Biological control alone or as a part of integrated vector management stands to be a better alternative to the chemical controls aimed against pest mosquitoes. At the same time it is necessary to control bacteria by synthetic or natural means (plant products. Hence the present study was designed to screen the effect of mosquito larvicidal and antimicrobial activitiy of protein isolated from matured leaves of Solanum villosum against mosquito immatures and some pathogenic bacteria. Methods Aqueous solvent extract of fresh mature leaves of S. villosum was tested against 3rd instar larvae of Anopheles stephensi, Culex quinquefasciatus and Stegomyia aegypti mosquitoes and against four pathogenic bacteria. The protein fraction was isolated and tested for mosquitocidal and antibacterial activities. Amino acid analysis was performed on isolated protein using PICO.TAG amino acid system. SDS-PAGE was also done to detect the bands of amino acid on the basis of their molecular weights. Results Proteins isolated from mature leaves of S. villosum were found to have larvicidal and antimicrobial properties. Analysis of the isolated protein identified fifteen amino acids of which eight were essential amino acids. SDS-PAGE detected seven bands corresponding to different molecular weights in the range of 69–109 KDa. Conclusion Proteins of mature leaves of S. villosum exhibited moderate larvicidal and antimicrobial activities. The study provides considerable scope in exploiting local indigenous resources for isolation of antimicrobial and mosquito larvicidal proteins.

Chandra Goutam

2008-12-01

320

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

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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.

Hati A K

1995-01-01

321

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

Science.gov (United States)

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

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

2012-11-01

322

Structure-activity relationship studies on the mosquito toxicity and biting deterrency of callicarpenal derivatives.  

Science.gov (United States)

Callicarpenal (=13,14,15,16-tetranorclerod-3-en-12-al=[(1S,2R,4aR,8aR)-1,2,3,4,4a,7,8,8a-octahydro-1,2,4a,5-tetramethylnaphthalen-1-yl]acetaldehyde; 1) has previously demonstrated significant mosquito bite-deterring activity against Aedes aegypti and Anopheles stephensi in addition to repellent activity against host-seeking nymphs of the blacklegged tick, Ixodes scapularis. In the present study, structural modifications were performed on callicarpenal (1) in an effort to understand the functional groups necessary for maintaining and/or increasing its activity and to possibly lead to more effective insect control agents. All modifications in this study targeted the C(12) aldehyde or the C(3) alkene functionalities or combinations thereof. Mosquito biting deterrency appeared to be influenced most by C(3) alkene modification as evidenced by catalytic hydrogenation that resulted in a compound having significantly less effectiveness than 1 at a test amount of 25 nmol/cm2. Oxidation and/or reduction of the C(12) aldehyde did not diminish mosquito biting deterrency, but, at the same time, none of the modifications were more effective than 1 in deterring mosquito biting. Toxicities of synthesized compounds towards Ae. aegypti ranged from an LD50 value of 2.36 to 40.11 microg per mosquito. Similarly, LD95 values ranged from a low of 5.59 to a high of 104.9 microg. PMID:19353538

Cantrell, Charles L; Klun, Jerome A; Pridgeon, Julia; Becnel, James; Green, Solomon; Fronczek, Frank R

2009-04-01

323

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

Science.gov (United States)

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.

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

2012-05-01

324

Mosquito larvae change their feeding behavior in response to kairomones from some predators.  

Science.gov (United States)

The efficacy of using predators for the biological control of mosquito disease vectors will be reduced if mosquito larvae respond to predator presence. The larvae of two mosquito species were investigated to study whether they responded to predator kairomones by increasing surface filter-feeding, which is a less active and thus less risky feeding strategy than bottom feeding. Culex quinquefasciatus Say is normally found in highly polluted water, where it will have little contact with predators. Except for some third instars, its larvae showed no response to four different types of predators. Culiseta longiareolata Macquart, living in rain-filled rock pools, is frequently attacked by a range of predators. All instars tested (second, third, and fourth instars) strongly responded to chemicals from dragonfly nymphs (Crocothemis erythraea Brullé), damselfly nymphs (Ischnura evansi Morton), and the fish Aphanius dispar Ruppel. However, they did not respond to final-instar water scorpions (Nepa cinerea L.), which would not feed on the mosquito larvae. Second- and third-instar Cs. longiareolata produced the same response to chopped up mosquito larvae as they did to dragonfly nymphs, but fourth instars produced a significantly stronger response to dragonfly nymphs-both those unfed and those fed in situ. Thus, Cs. longiareolata not only identified different predators and responded accordingly, but also responded to conspecific alarm pheromones. Cx quinquefasciatus showed little response to predators or to alarm pheromones from damaged conspecific larvae. PMID:24724285

Roberts, Derek

2014-03-01

325

Discovery of an alternate metabolic pathway for urea synthesis in adult Aedes aegypti mosquitoes.  

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We demonstrate the presence of an alternate metabolic pathway for urea synthesis in Aedes aegypti mosquitoes that converts uric acid to urea via an amphibian-like uricolytic pathway. For these studies, female mosquitoes were fed a sucrose solution containing (15)NH4Cl, [5-(15)N]-glutamine, [(15)N]-proline, allantoin, or allantoic acid. At 24 h after feeding, the feces were collected and analyzed in a mass spectrometer. Specific enzyme inhibitors confirmed that mosquitoes incorporate (15)N from (15)NH4Cl into [5-(15)N]-glutamine and use the (15)N of the amide group of glutamine to produce labeled uric acid. More importantly, we found that [(15)N2]-uric acid can be metabolized to [(15)N]-urea and be excreted as nitrogenous waste through an uricolytic pathway. Ae. aegypti express all three genes in this pathway, namely, urate oxidase, allantoinase, and allantoicase. The functional relevance of these genes in mosquitoes was shown by feeding allantoin or allantoic acid, which significantly increased unlabeled urea levels in the feces. Moreover, knockdown of urate oxidase expression by RNA interference demonstrated that this pathway is active in females fed blood or (15)NH4Cl based on a significant increase in uric acid levels in whole-body extracts and a reduction in [(15)N]-urea excretion, respectively. These unexpected findings could lead to the development of metabolism-based strategies for mosquito control. PMID:18182492

Scaraffia, Patricia Y; Tan, Guanhong; Isoe, Jun; Wysocki, Vicki H; Wells, Michael A; Miesfeld, Roger L

2008-01-15

326

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

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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.

Sandipan Gupta and Samir Banerjee

2013-01-01

327

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

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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.

Olson Kenneth E

2010-01-01

328

Do herbicide treatments reduce the sensitivity of mosquito larvae to insecticides?  

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Invasive mosquitoes are economic and sanitary concerns especially in Europe and America. Most work has emphasized the role of resistance [Berrada, S., Fournier, D., Cuany, A., Nguyen, T.X., 1994. Identification of resistance mechanisms in a selected laboratory strain of Cacopsylla pyri (Homoptera: Psyllidae): altered acetylcholinesterases and detoxifying oxidases. Pesticide Biochemistry and Physiology 48, 41-47; Hemingway, J., Hawkes, N.J., McCarroll, L., Ranson, H., 2004. The molecular basis of insecticide resistance in mosquitoes. Insect Biochemistry and Molecular Biology 34, 653-665] to insecticides. Compounds acting on larval sensitivity to insecticides are not well studied and their action remains poorly understood. Among several residual chemicals in ecosystems, particularly in wetlands, we identified a possible interaction of an herbicide on larval resistance to an insecticide. Our work contributes to the global control of mosquito populations by identifying possible pathways of resistance to insecticides of these vectors. Resistance or tolerance to insecticide treatments might contribute to successful invasion by mosquitoes. Here we report an ecotoxicological approach to test the hypothesis of an indirect effect of atrazine on mortality of an invasive vector. A brief contact (48h) between Aedes aegypti mosquito larvae and atrazine led to a modification of larval sensitivity to an insecticide: using atrazine as an inducer led to a decrease in the mortality of larvae treated with Bacillus thuringiensis var. israelensis (Bti). PMID:16574189

Boyer, Sébastien; Sérandour, Julien; Lempérière, Guy; Raveton, Muriel; Ravanel, Patrick

2006-10-01

329

Evidence of carbamate resistance in urban populations of Anopheles gambiae s.s. mosquitoes resistant to DDT and deltamethrin insecticides in Lagos, South-Western Nigeria  

OpenAIRE

Abstract Background Resistance monitoring is essential in ensuring the success of insecticide based vector control programmes. This study was carried out to assess the susceptibility status of urban populations of Anopheles gambiae to carbamate insecticide being considered for vector control in mosquito populations previously reported to be resistant to DDT and permethrin. Methods Two – three day old adult female Anopheles mosquitoes reared f...

Oduola Adedayo O; Idowu Emmanuel T; Oyebola Muyiwa K; Adeogun Adedapo O; Olojede Judith B; Otubanjo Olubunmi A; Awolola Taiwo S

2012-01-01

330

A field bioassay to evaluate potential spatial repellents against natural mosquito populations.  

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A field bioassay evaluating candidate chemicals as aerial repellents was developed and evaluated against natural mosquito populations in Beltsville, MD. The bioassay consisted of an attractive source surrounded by a grid of 16 septa containing a volatile candidate aerial repellent, compared with an attractive source without such a grid. The attractive source was a Centers for Disease Control and Prevention light trap supplemented with carbon dioxide. Significant sources of variation included weather, position, and the differential response of mosquito species. Despite these sources of variation, significant repellent responses were obtained for catnip oil, E,Z-dihydronepetalactone, and DEET. PMID:23393752

Chauhan, K R; Aldrich, J R; McCardle, P W; White, G B; Webb, R E

2012-12-01

331

Mosquitoes (Diptera: Culicidae) in relation to the risk of disease transmission in El Ismailia Governorate, Egypt.  

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Mosquito were surveyed (Nov. 2009 - March 2010) in El Ismailia Governorate. Nine species were reported: Culex pipiens, Cx. perexiguus, Cx. antennatus, Anopheles tenebrosus, An. pharoensis, An. multicolor, Ochlerotatus detritus, Oc. caspius and Culiseta longiareolata. Culex pipiens was the predominant species (ca. 87% larvae and 57% adults). For the 3 common species, Cx. pipiens, Cx. perexiguus, and Cx. antennatus the following were examined: (1) the type and characteristics (temperature and pH) of the breeding habitats and their relation to the larval density and (2) the relation of adult indoor density to the indoor and outdoor temperature and RH. The abundance of mosquito vectors in El Ismailia with its old history of vector transmitted diseases contributes to the risk of mosquito borne disease transmission in this area. This would assist in the control activities. PMID:21980773

Abdel-Hamid, Yousrya M; Soliman, Mohamed I; Kenawy, Mohamed A

2011-08-01

332

Isonicotinic acid hydrazide: an anti-tuberculosis drug inhibits malarial transmission in the mosquito gut.  

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We studied the transmission-blocking effect of isonicotinic acid hydrazide (INH), a widely used anti-tuberculosis drug, against Plasmodium gallinaceum and Plasmodium berghei. INH-treatment of infected animals did not inhibit parasite development in the blood of the vertebrate host, but did inhibit exflagellation, ookinete formation, and oocyst development in the mosquito. Oocyst development was inhibited in a dose-dependent manner. The ED(50) in the P. gallinaceum/chicken/Aedes aegypti model and P. berghei/mouse/Anopheles stephensi model was 72 and 109 mg/kg, respectively. In marked contrast, in vitro exflagellation and ookinete development were not directly affected by physiological concentrations of INH. We suggest that INH exerts its inhibitory effects on the mosquito stages of the malaria parasite by an indirect, and at present undefined mechanism. Further elucidation of the mechanism how INH inhibits parasite development specifically on mosquito stages may allow us to identify new targets for malaria control strategy. PMID:15013786

Arai, Meiji; Alavi, Yasmene I H; Mendoza, Jacqueline; Billker, Oliver; Sinden, Robert E

2004-01-01

333

Field evaluation of four spatial repellent devices against Arkansas rice-land mosquitoes.  

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Four commercially available spatial repellent devices were tested in a rice-land habitat near Stuttgart, AR, after semi-field level assessments had been made at the Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, US Department of Agriculture in Gainesville, FL. OFF! Clip-On(metofluthrin), Mosquito Cognito (linalool), No-Pest Strip (dichlorvos), and ThermaCELL (d-cisltrans allethrin) were selected for this study from >20 candidate products. The units based on metofluthrin, linalool, or d-cisltrans allethrin significantly reduced captures of 1 or more of the mosquito species at surrogate human sites (unlit Centers for Disease Control and Prevention traps with CO2 and octenol). Among the mosquito species analyzed statistically (Anopheles quadrimaculatus, Culex erraticus, and Psorophora columbiae), there were significantly different responses (up to 84% reduction) to individual products, suggesting that combinations of certain spatial repellents might provide significantly greater protection. PMID:24772674

Dame, David A; Meisch, Max V; Lewis, Carolyn N; Kline, Daniel L; Clark, Gary G

2014-03-01

334

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

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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.

Mnyone Ladslaus L

2010-08-01

335

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

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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.

Flahault Antoine

2005-05-01

336

Mosquito (Diptera: Culicidae) Fauna of Qom Province, Iran  

OpenAIRE

Background: There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province.Methods: To study the mosquito (Diptera: Culicidae) fauna, larval collections were carried out from different habitats on 19 occasions usi...

Saghafipour, A.; MR Abai; Farzinnia, B.; Nafar, R.; Ladonni, H.; Azari-hamidian, S.

2012-01-01

337

Fabrication of an olfactometer for mosquito behavioural studies  

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Full Text Available Background & objectives: Olfaction is the major sensory modality involved in the resource searchingbehaviour of insects including vector mosquitoes (Diptera: Culicidae. To date, our current countrywideknowledge on the host-seeking behaviour of Iranian mosquitoes is mainly confined to hostpreference which has exclusively come from field studies. Olfactometer is a scientific tool bywhich more naive aspects of man-vector contact can be clarified under controlled and less biasedconditions.Methods: The wind tunnel and stimulus delivery system was constructed from acrylic materialsbased on previously introduced models with some modifications. Air supply and required lightwere ensured by a powerful compressor and incandescent bulbs, respectively. Desired level oftemperature was maintained by controllable heating radiators. For humidity production a uniquein-built piezo system was devised in the course of the air flow. Fine regulators facilitated thecontinuous generatation of the humidity at a preset level.Results: Titanium tetrachloride smoke plus monitoring of the wind speed revealed that the flow ofair was proper and invariable. A desired level of humidity and temperature could be set up in just10 and 15–45 min, respectively. These physical parameters varied only ±2% (humidity and±0.15ºC (temperature in a typical 20 min duration.Conclusion: The first sophisticated olfactometer in the field of medical entomology in Iran isreported here. Fast set up and stability of physical parameters are its salient features. It is expectedthat with the aid of this olfactometer further information on the physiological principles of thehost-seeking behaviour of mosquitoes become available soon.

Seyed-Mohammad Omrani,Hassan Vatandoost,Mohammad Ali Oshaghi,Mohammad Reza Yaghoobi Ershadi,Yavar Rassi, Siavash Tirgari

2010-03-01

338

The effect of oral anthelmintics on the survivorship and re-feeding frequency of anthropophilic mosquito disease vectors.  

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In the Tropics, there is substantial temporal and spatial overlap of diseases propagated by anthropophilic mosquito vectors (such as malaria and dengue) and human helminth diseases (such as onchocerciasis and lymphatic filariasis) that are treated though mass drug administrations (MDA). This overlap will result in mosquito vectors imbibing significant quantities of these drugs when they blood feed on humans. Since many anthelmintic drugs have broad anti-invertebrate effects, the possibility of combined helminth control and mosquito-borne disease control through MDA is apparent. It has been previously shown that ivermectin can reduce mosquito survivorship when administered in a blood meal, but more detailed examinations are needed if MDA is to ever be developed into a tool for malaria or dengue control. We examined concentrations of drugs that follow human pharmacokinetics after MDA and that matched with mosquito feeding times, for effects against the anthropophilic mosquito vectors Anopheles gambiae s.s. and Aedes aegypti. Ivermectin was the only human-approved MDA drug we tested that affected mosquito survivorship, and only An. gambiae s.s. were affected at concentrations respecting human pharmacokinetics at indicated doses. Ivermectin also delayed An. gambiae s.s. re-feeding frequency and defecation rates, and two successive ivermectin-spiked blood meals following human pharmacokinetic concentrations compounded mortality effects compared to controls. These findings suggest that ivermectin MDA in Africa may be used to decrease malaria transmission if MDAs were administered more frequently. Such a strategy would broaden the current scope of polyparasitism control already afforded by MDAs, and which is needed in many African villages simultaneously burdened by many parasitic diseases. PMID:20540931

Kobylinski, Kevin C; Deus, Kelsey M; Butters, Matthew P; Hongyu, Tan; Gray, Meg; da Silva, Ines Marques; Sylla, Massamba; Foy, Brian D

2010-11-01

339

Esbiothrin-impregnated ropes as mosquito repellent.  

Science.gov (United States)

Esbiothrin [(+/-)-3-allyl-2-methyl-4-oxocylopent-2-enyl-(+)-trans- chrysanthemate] is an improved isomeric composition of allethrin series and consists essentially of esters of chrysanthemic acid and allethrolone. Jute rope was impregnated with esbiothrin and the smoke from smouldering ropes was evaluated as mosquito repellent in human dwellings and cattlesheds with open doors and windows at different dosages. Esbiothrin-impregranted (500 ppm) ropes prevented the entry of more than 95% An. culicifacles and other anophelines, 90.9-88.8% Culex quinquefasciatus and 96-95.1% total mosquitoes in open rooms of houses and cattlesheds respectively. The impact of ropes was more pronounced on the biting rate of mosquitoes. Indoors and outdoors human baits seated at a distance of about 3 m from smouldering esbiothrin ropes experienced no bite at all from An. culicifacies. An iron mesh around the rope prevents fire hazards. PMID:1291341

Ansari, M A; Sharma, V P; Razdan, R K

1992-12-01

340

Evaluation of botanicals as repellents against mosquitoes.  

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Repellent properties of three plant extracts--essential oil (steam distillate) of Zanthoxylum limonella (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 the repellents were evaluated. Repellents in mustard oil afforded longer protection time against the bites 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 in coconut oil exhibited 223.5-245 min protection time at the same concentration. Oil of Z. limonella gave the highest protection time against the bites of Aedes (S.) albopictus mosquitoes at all the concentrations than other herbal repellents tested both in mustard and coconut oil. PMID:15119071

Das, N G; Baruah, I; Talukdar, P K; Das, S C

2003-01-01

341

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

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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. PMID:20846414

Reichard, Martin; Watters, Brian R; Wildekamp, Rudolf H; Sonnenberg, Rainer; Nagy, Béla; Polacik, Matej; Valdesalici, Stefano; Cellerino, Alessandro; Cooper, Barry J; Hengstler, Holger; Rosenstock, John; Sainthouse, Ian

2010-01-01

342

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

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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.

Reichard Martin

2010-09-01

343

Efficacy, fate, and potential effects on salmonids of mosquito larvicides in catch basins in Seattle, Washington.  

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We investigated the efficacy, fate, and potential for direct effects on salmonids of 4 common mosquito larvicides (Mosquito Dunks and Bits (AI: Bacillis thuringiensis var. israelensis, [Bti]), VectoLex WSP (AI: Bacillus sphaericus [Bs], VectoLex CG [AI: Bs], and Altosid Briquets [AI: s-methoprene]) in Seattle, WA, during 3 summers. During efficacy trials in 2006, all treatments resulted in a rapid reduction in number of mosquito pupae (Mosquito Dunks and Bits and VectoLex WSP) or emergence success (Altosid Briquets). VectoLex CG was chosen for city-wide application in 2007 and 2008. The average counts of pupae within round-top basins remained significantly below the control average for 11 wk in 2007, whereas efficacy in grated-top basins was short-lived. In 2008 the average counts of pupae within grated-top basins remained significantly below the control average for 10 wk. Altosid XR was also effective in reducing adult emergence within grated basins in 2008. In 2007 and 2008, frequent precipitation events made the evaluation of efficacy difficult due to reductions in pupae across control and treated basins. Four separate analyses of VectoLex products revealed that the product was a combination of Bs and Bti. Both Bs and Bti were detected in 3 urban creeks connected to treated basins in 2007 and 2008. Laboratory toxicity test results suggest that concentrations of Bs and Bti detected in each of the watersheds pose little direct hazard to juvenile salmonids. PMID:23833901

Sternberg, Morgan; Grue, Christian; Conquest, Loveday; Grassley, James; King, Kerensa

2012-09-01

344

Defects in coatomer protein I (COPI) transport cause blood feeding-induced mortality in Yellow Fever mosquitoes.  

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Blood feeding by vector mosquitoes provides the entry point for disease pathogens and presents an acute metabolic challenge that must be overcome to complete the gonotrophic cycle. Based on recent data showing that coatomer protein I (COPI) vesicle transport is involved in cellular processes beyond Golgi-endoplasmic reticulum retrograde protein trafficking, we disrupted COPI functions in the Yellow Fever mosquito Aedes aegypti to interfere with blood meal digestion. Surprisingly, we found that decreased expression of the ?COPI coatomer protein led to 89% mortality in blood-fed mosquitoes by 72 h postfeeding compared with 0% mortality in control dsRNA-injected blood-fed mosquitoes and 3% mortality in ?COPI dsRNA-injected sugar-fed mosquitoes. Similar results were obtained using dsRNA directed against five other COPI coatomer subunits (?, ?, ?', ?, and ?). We also examined midgut tissues by EM, quantitated heme in fecal samples, and characterized feeding-induced protein expression in midgut, fat body, and ovary tissues of COPI-deficient mosquitoes. We found that COPI defects disrupt epithelial cell membrane integrity, stimulate premature blood meal excretion, and block induced expression of several midgut protease genes. To study the role of COPI transport in ovarian development, we injected ?COPI dsRNA after blood feeding and found that, although blood digestion was normal, follicles in these mosquitoes were significantly smaller by 48 h postinjection and lacked eggshell proteins. Together, these data show that COPI functions are critical to mosquito blood digestion and egg maturation, a finding that could also apply to other blood-feeding arthropod vectors. PMID:21628559

Isoe, Jun; Collins, Jennifer; Badgandi, Hemant; Day, W Anthony; Miesfeld, Roger L

2011-06-14

345

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

Science.gov (United States)

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

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

346

Role of the yellow fever virus structural protein genes in viral dissemination from the Aedes aegypti mosquito midgut.  

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Live-attenuated virus vaccines are key components in controlling arboviral diseases, but they must not disseminate in or be transmitted by mosquito vectors. Although the cycles in which many mosquito-borne viruses are transmitted are well understood, the role of viral genetics in these processes has not been fully elucidated. Yellow fever virus (YFV) is an important arbovirus and the prototype member of the family Flaviviridae. Here, YFV was used in Aedes aegypti mosquitoes as a model to investigate the genetic basis of infection and dissemination in mosquitoes. Viruses derived from infectious clones and chimeric viruses with defined sequential manipulations were used to investigate the influence of specific sequences within the membrane and envelope structural protein genes on dissemination of virus from the mosquito midgut. Substitution of domain III of the envelope protein from a midgut-restricted YFV into a wild-type YFV resulted in a marked decrease in virus dissemination, suggesting an important role for domain III in this process. However, synergism between elements within the flavivirus structural and non-structural protein genes may be necessary for efficient virus escape from the mosquito midgut. PMID:16963758

McElroy, Kate L; Tsetsarkin, Konstantin A; Vanlandingham, Dana L; Higgs, Stephen

2006-10-01

347

Modelling releases of sterile mosquitoes with different strategies.  

Science.gov (United States)

To prevent the transmissions of malaria, dengue fever, or other mosquito-borne diseases, one effective weapon is the sterile insect technique in which sterile mosquitoes are released to reduce or eradicate the wild mosquito population. To study the impact of the sterile insect technique on disease transmission, we formulate discrete-time mathematical models, based on difference equations, for the interactive dynamics of the wild and sterile mosquitoes, incorporating different strategies in releasing sterile mosquitoes. We investigate the model dynamics and compare the impact of the different release strategies. Numerical examples are given to demonstrate rich dynamical features of the models. PMID:25377433

Li, Jia; Yuan, Zhiling

2015-01-01

348

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

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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.

Thomas Matthew B

2011-07-01

349

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

OpenAIRE

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 seri...

Reichard Martin; Watters Brian R; Wildekamp Rudolf H; Sonnenberg Rainer; Nagy Béla; Pola?ik Matej; Valdesalici Stefano; Cellerino Alessandro; Cooper Barry J; Hengstler Holger; Rosenstock John; Sainthouse Ian

2010-01-01

350

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

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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.

Kamareddine Layla

2013-01-01

351

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

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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.

Analía Francia

2011-12-01

352

Biological assay methods for mosquito repellents.  

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Three biological assay procedures for repellents are currently documented in the literature: 1) ASTM E951-94, Laboratory testing of non-commercial repellent formulations on the skin. 2) ASTM E939-94, Field testing topical applications of compounds as repellents for medically important and pest arthropods. 1. Mosquitoes. 3) WHO/CTD/WHOPES/IC/96.1, Report of WHOPES informal consultation on the evaluation and testing of insecticides. One public draft set of repellent-testing guidelines is available on the internet: 4) USEPA OPPTS 810.3700, Product performance test guidelines. Insect repellents for human skin and outdoor premises. In practice, the outcome of a repellent bioassay using any of these procedures is affected by the absorption, penetration, and chemical modification of repellent on skin and by evaporation, abrasion, and perspiration. Other abiotic factors that influence mosquito responses to repellent stimuli are light, temperature, humidity, repellent dose, exposure time, and test-cage shape and size. Biotic variables in repellent bioassays are larval nutrition, carbohydrate availability for adult mosquitoes, age and parity of females, and differences in the innate attraction/ repellency of test subjects. Geographic location and seasonal and diel activity cycles in mosquitoes determine when and where repellents can be tested in the field. Critical knowledge of these sources of variation can be converted to improved precision and accuracy in repellent bioassays and the resulting information used to efficiently select new repellent compounds for toxicological evaluation and field testing. PMID:16921678

Barnard, Donald R

2005-12-01

353

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

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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

2010-01-01

354

Mosquito survey during West Nile virus outbreak 2012 in northeast Croatia.  

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During the August and September 2012, seven human cases of the West Nile neuro-invasive disease were reported in Croatia. Medical entomology research on a potential vectors during the outbreak was supported by the Ministry of Health. A mosquito survey has been done in 64 sites in three eastern Croatian counties (Osijek-Baranja County, Vukovar-Srijem county and in Brod-Posavina county). Dry ice baited CDC traps were used for mosquito sampling in a period from the 10th to 25th September 2012. A total of 1785 mosquitoes were collected and 5 species were determined. The most numerous species were Aedes vexans with 1634 specimens, a Culex pipiens c., the potential vector of WNV, was present with 6.39%, in 114 specimens. That species was present in 43 out of 64 investigated sites. Vector control included both the control of mosquito larvae and the adults. Treatments have been done on 184 small breeding sites and on 2900 ha of an urban area. PMID:25144969

Merdi?, Enrih; Vignjevi?, Goran; Turi?, Natasa; Bogojevi?, Mirta Sudari?; Milas, Josip; Vru?ina, Ivana; Zahirovi?, Zeljko

2014-06-01

355

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

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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

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

2014-05-01

356

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  

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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.

IDALYD FONSECA

2005-12-01

357

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

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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.

MAYDA CASTEX

1997-08-01

358

Semliki Forest virus infection of mosquito cells : novel insights into host responses and antiviral immunity  

OpenAIRE

Arboviruses are transmitted between vertebrate hosts by arthropod vectors, such as mosquitoes or ticks. In vertebrates arboviruses cause cytopathic effects and disease, however, arbovirus infection of arthropods usually results in persistence. Control of arboviral infection is mediated by the arthropod’s immune system. Pathways such as RNAi, JAK/STAT, Toll and IMD have previously been implicated in controlling arbovirus infections. In contrast, the antiviral role of other pat...

Rodriguez, Julio

2013-01-01

359

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

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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

Lantova, Lucie; Volf, Petr

2014-12-01

360

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

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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.

Byarugaba Wilson

2009-07-01

361

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

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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.

David A. Adebote

2008-02-01

362

Toxicological Effects of Inhaled Mosquito Coil Smoke on the Rat Spleen: A Haematological and Histological Study  

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Full Text Available The effect of inhaling mosquito coil smoke on the haematology and histology of the rats spleen was studied. A total of 30 albino rats of the Wister strain were used in this study, they were divided into six groups of five rats each. Rats in Group I served as control (no exposure to mosquito coil smoke. While Groups II-VI were exposed to mosquito coil smoke for 12 h, 7, 14, 21 and 28 days, respectively. At the end of each experimental period, blood was collected from each rat for the analysis of Red Blood Cell (RBC count, White Blood Cell (WBC count, Haemoglobin (Hb concentration, Packed Cell Volume (PCV and the percentages of Neutrophils, Monocytes, Eosinophils, Basophils and Lymphocytes. The rats were then sacrificed and the spleen obtained, was processed for routine histological analysis. Haematological analysis of the blood obtained revealed a significant (p<0.01, 0.05 increase in WBC count in all exposure periods, while analysis of differential leucocyte count revealed a significant (p<0.05 increase in basophil and lymphocyte percentages. Histological analysis of the spleen tissue revealed severe congestion of venous sinusoids, hyperplasia and regression of both the red and white pulps. Results from this study demonstrates that mosquito coil smoke inhalation challenges the immune system in experimental rats, however, the precise mechanisms remain to be clarified in more detailed studies.

S.H. Garba

2007-01-01

363

Behavioral and electroantennographic responses of the tea mosquito, Helopeltis theivora, to female sex pheromones.  

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Responses of the tea mosquito, Helopeltis theivora (Waterhouse) (Hemiptera: Miridae), a major pest of tea, to female sex pheromone compounds were measured using wind tunnel and electroantennogram (EAG) bioassays. In the wind tunnel, male tea mosquitoes were found to be most attracted to a dichloromethane extract of the female thorax. Gas chromatography-mass spectrometry (GC-MS) analysis of female thoracic extracts and dynamic head space samples of virgin females showed the presence of five compounds: (Z)-3 hexenyl acetate, (Z)-3 hexenyl butanoate, (E)-2 hexenyl pentanoate, 2,4 dimethyl pentanal, and (E)-2-hexenol. Male tea mosquitoes were attracted to blends of (Z)-3 hexenyl acetate and (E)-2-hexenol in the wind tunnel with a 1:5 ratio eliciting the greatest response. EAG recordings of male antenna confirmed the ability of this blend to evoke antennal responses in male insects. Similarly active EAG responses were recorded toward female thoracic extract and a blend of (Z)-3 hexenyl acetate and (E)-2-hexenol. Behavioral responses of adult males are mediated by a blend of volatile female sex pheromone compounds, (Z)-3 hexenyl acetate and (E)-2-hexenol, at a ratio of 1:5. This female sex pheromone blend may be useful for tea mosquito control and management programs. PMID:19161684

Sachin, James P; Selvasundaram, R; Babu, A; Muraleedharan, N

2008-12-01

364

Hydrology and Mosquito Population Dynamics around a Hydropower Reservoir in Africa  

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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.

Endo, N.; Eltahir, E. A.

2013-12-01

365

Ecology of anopheline mosquitoes (Diptera: Culicidae) in the Central Atlantic Forest Biodiversity Corridor, southeastern Brazil.  

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Knowledge of the fauna composition of anopheline mosquitoes, their ecological aspects and behavior, and influence of climatic variables on their population dynamics can help in understanding the transmission of Plasmodium parasites and thus develop more efficient strategies for the control of malaria. In the Central Atlantic Forest Biodiversity Corridor, southeastern Brazil, foci of introduced malaria have been reported among people returning from the Amazon region, north Brazil. Our objective was to evaluate and compare the anopheline fauna from a preserved environment and an adjacent peridomiciliary modified environment at the Central Atlantic Forest Biodiversity Corridor. We collected anopheline mosquitoes on a monthly basis from June 2004 to May 2006 from both these environments to understand the ecological aspects and their association with the occurrence of malaria. We captured 5,491 anopheline mosquitoes belonging to two subgenera and 11 species and studied the correlations between anopheline mosquito species and climatic variables. We considered Anopheles darlingi (Root) as the principal malaria vector and Anopheles albitarsis s. l. (Arribalzaga) as the secondary vector. PMID:23427648

Da Silva, Kleber S; Pinto, Israel De S; Leite, Gustavo R; Das Virgens, Thieres M; Dos Santos, Claudiney B; Falqueto, Aloísio

2013-01-01

366

microRNA miR-275 is indispensable for blood digestion and egg development in the mosquito Aedes aegypti.  

Science.gov (United States)

The mosquito Aedes aegypti is the major vector of arboviral diseases, particularly of Dengue fever, of which there are more than 100 million cases annually. Mosquitoes, such as A. aegypti, serve as vectors for disease pathogens because they require vertebrate blood for their egg production. Pathogen transmission is tightly linked to repeated cycles of obligatory blood feeding and egg maturation. Thus, the understanding of mechanisms governing egg production is necessary to develop approaches that limit the spread of mosquito-borne diseases. Previous studies have identified critical roles of hormonal- and nutrition-based target of rapamycin (TOR) pathways in controlling blood-meal-mediated egg maturation in mosquitoes. In this work, we uncovered another essential regulator of blood-meal-activated processes, the microRNA miR-275. The depletion of this microRNA in A. aegypti females after injection of its specific antagomir resulted in severe defects in blood digestion, fluid excretion, and egg development, clearly demonstrating that miR-275 is indispensable for these physiological processes. miR-275 exhibits an expression profile that suggests its regulation by a steroid hormone, 20-hydroxyecdysone (20E). In vitro organ culture experiments demonstrated that miR-275 is induced by this hormone in the presence of amino acids, indicative of a dual regulation by 20E and TOR. This report has uncovered the critical importance of microRNAs in controlling blood-meal-activated physiological events required for completion of egg development in mosquito disease vectors. PMID:21115818

Bryant, Bart; Macdonald, Warren; Raikhel, Alexander S

2010-12-28

367

MicroRNA-8 targets the Wingless signaling pathway in the female mosquito fat body to regulate reproductive processes.  

Science.gov (United States)

Female mosquitoes require a blood meal for reproduction, and this blood meal provides the underlying mechanism for the spread of many important vector-borne diseases in humans. A deeper understanding of the molecular mechanisms linked to mosquito blood meal processes and reproductive events is of particular importance for devising innovative vector control strategies. We found that the conserved microRNA miR-8 is an essential regulator of mosquito reproductive events. Two strategies to inhibit miR-8 function in vivo were used for functional characterization: systemic antagomir depletion and spatiotemporal inhibition using the miRNA sponge transgenic method in combination with the yeast transcriptional activator gal4 protein/upstream activating sequence system. Depletion of miR-8 in the female mosquito results in defects related to egg development and deposition. We used a multialgorithm approach for miRNA target prediction in mosquito 3' UTRs and experimentally verified secreted wingless-interacting molecule (swim) as an authentic target of miR-8. Our findings demonstrate that miR-8 controls the activity of the long-range Wingless (Wg) signaling by regulating Swim expression in the female fat body. We discovered that the miR-8/Wg axis is critical for the proper secretion of lipophorin and vitellogenin by the fat body and subsequent accumulation of these yolk protein precursors by developing oocytes. PMID:25605933

Lucas, Keira J; Roy, Sourav; Ha, Jisu; Gervaise, Amanda L; Kokoza, Vladimir A; Raikhel, Alexander S

2015-02-01

368

Reduction in incidence and prevalence of Plasmodium falciparum in under-5-year-old children by permethrin impregnation of mosquito nets*  

OpenAIRE

The malaria incidence and prevalence rates among children who slept under permethrin-impregnated mosquito nets in four villages near Madang, Papua New Guinea, were compared with the rates among children who slept under unimpregnated nets in four paired control villages. Immediately following a parasitological survey in the eight villages, malaria parasites were cleared from the children with chemotherapy, and the mosquito nets in the four experimental villages were impregnated with permethrin...

Graves, P. M.; Brabin, B. J.; Charlwood, J. D.; Burkot, T. R.; Cattani, J. A.; Ginny, M.; Paino, J.; Gibson, F. D.; Alpers, M. P.

1987-01-01

369

A 3D Analysis of Flight Behavior of Anopheles gambiae sensu stricto Malaria Mosquitoes in Response to Human Odor and Heat  

OpenAIRE

Female mosquitoes use odor and heat as cues to navigate to a suitable landing site on their blood host. The way these cues affect flight behavior and modulate anemotactic responses, however, is poorly understood. We studied in-flight behavioral responses of females of the nocturnal malaria mosquito Anopheles gambiae sensu stricto to human odor and heat. Flight-path characteristics in a wind tunnel (flow 20 cm/s) were quantified in three dimensions. With wind as the only stimulus (control), sh...

Spitzen, J.; Spoor, C. W.; Grieco, F.; Braak, C. J. F.; Beeuwkes, J.; Brugge, S. P.; Kranenbarg, S.; Noldus, L.; Leeuwen, J. L.; Takken, W.

2013-01-01

370

Population dynamics and spatial structure of human-biting mosquitoes, inside and outside of houses, in the Chockwe irrigation scheme, southern Mozambique.  

Science.gov (United States)

Focal control of malaria vectors, a potentially cost-effective alternative to conventional control, requires a spatio-temporal understanding of the mosquitoes. Trapping of African malaria vectors has generally been limited to inside houses making distribution estimates dependent on the location of dwellings. The development of tent-traps to sample outdoor biting mosquitoes has enabled more independent estimates. Here we describe both temporal and spatial variation in mosquito movements in an irrigation project village in southern Mozambique. Six hundred and ninety-three tent-trap collections (525 of which were paired with light-trap collections), 552 exit collections and 391 collections of mosquitoes resting inside houses were undertaken from March 2005 to April 2006. Fifteen species of mosquito were collected (five exclusively as larvae). Mansonia africana was the most common finding, numbers being greatest away from the village. Only Anopheles funestus, An. tenebrosus and Culex quinquefasciatus were collected in greater numbers in light-traps compared to tent-traps. Among the common mosquitoes, correlations in numbers of mosquito collected in paired tent and in light-traps were significant for all but An. tenebrosus. Inverse distance weighting was used to produce raster density maps of the most common mosquitoes. All species, with minor variations, in both hot and cool seasons, were collected in greatest numbers close to the edges of the village where water suitable for larval development was available. All exophilic anophelines species tested negative for sporozoites. It is suggested that focal control of larvae, applied by the villagers themselves, could be a suitable alternative to conventional control in this and similar villages. PMID:23733293

Charlwood, J Derek; Macia, Gracieta A; Manhaca, Maria; Sousa, Bruno; Cuamba, Nelson; Bragança, Mauro

2013-05-01

371

Ord River arboviruses--isolations from mosquitoes.  

Science.gov (United States)

One hundred and thirty presumptive viruses have been isolated from 485 pools made from 23,872 mosquitoes collected in the Ord River area of North-West Australia. One hundred and eleven of the virus isolates isolates came from pools of Culex annulirostis, the dominant mosquito species caught in the vicinity of Kununurra. Forty-five of the viruses pathogenic for newborn mice have been further characterized-19 as Flaviviruses, 1 Alphavirus, 9 Koongol, 1 Mapputta and 15 non-haemagglutinating viruses of which 6 are Corripata. Thirty-seven isolates were from Culex annulirostis, 7 from Aedomyia catasticta and 1 from aedes tremulus. All Corriparta isolates were from Aedomyia catasticta. The Flaviviruses comprised 13 Kunjin and 6 MVE isolates. PMID:14613

Liehne, C G; Leivers, S; Stanley, N F; Alpers, M P; Paul, S; Liehne, P F; Chan, K H

1976-10-01

372

Novel Flaviviruses Detected in Different Species of Mosquitoes in Spain  

OpenAIRE

We report the characterization of three novel flaviviruses isolated in Spain. Marisma Mosquito virus, a novel mosquito borne virus, was isolated from Ochlerotatus caspius mosquitoes; Spanish Ochlerotatus flavivirus and Spanish Culex flavivirus, two novel insect flaviviruses, were isolated from Oc. caspius and Culex pipiens, re- spectively. During this investigation, we designed a sensitive RT-nested polymerase chain reaction method that amplifies a 1019bp fragmen...

Va?zquez, Ana; Sa?nchez-seco, Mari?a-paz; Palacios, Gustavo; Molero, Francisca; Reyes, Noelia; Ruiz, Santiago; Aranda, Carles; Marque?s, Eduard; Escosa, Raul; Moreno, Juana; Figuerola, Jordi; Tenorio, Antonio

2012-01-01

373

Cues of mosquito host finding and oviposition site selection  

OpenAIRE

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

Afify, Ali

2014-01-01

374

Vector Competence of New Zealand Mosquitoes for Selected Arboviruses  

OpenAIRE

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...

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

2011-01-01

375

A role for endosomal proteins in alphavirus dissemination in mosquitoes  

OpenAIRE

Little is known about endosomal pathway proteins involved in arthropod-borne virus (arbovirus) assembly and cell-to-cell spread in vector mosquitoes. UNC93A and Synaptic vesicle-2 (SV2) proteins are involved in intracellular transport in mammals. They show amino acid sequence conservation from mosquitoes to humans, and their transcripts are highly-enriched in Aedes aegypti during arbovirus infection. Transient gene silencing of SV2 or UNC93A in mosquitoes infected with the recombinant alphavi...

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

2011-01-01

376

Advances in methods for colour marking of mosquitoes  

OpenAIRE

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...

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

2013-01-01

377