In addition to causing discomfort, female mosquitoes introduce disease-carrying viruses and bacteria into the bloodstream of their victims. There are numerous publications describing the uses of sugary mosquito baits ...In addition to causing discomfort, female mosquitoes introduce disease-carrying viruses and bacteria into the bloodstream of their victims. There are numerous publications describing the uses of sugary mosquito baits with promising results. Without temperature control measures however, these methods are mainly useful for only nectar-feeding insects, including male mosquitoes, because the warmth of the blood is a condition for the females to locate their meals. The efforts required to keep the baits fresh against the natural spoiling process make them less attractive or impractical to implement. These experiments address these issues by using warm baits of water, sugar, boric acid, and antibiotics. Overnight, the general areas became clear of blood-sucking female mosquitoes while in numbers, the harmless males concentrated into the immediate vicinities. Control vs. experiment protocol established no other logical explanation for this phenomenon other than that females were attracted and killed by the bait. As expected, there was no female mosquito’s activity in these areas. There weren’t many left to do the work.展开更多
In the context of mosquito control, a plethora of devices have been put on the market. The effectiveness of these devices is not always proven, but some have interesting principles that have the potential to be a good...In the context of mosquito control, a plethora of devices have been put on the market. The effectiveness of these devices is not always proven, but some have interesting principles that have the potential to be a good means of mosquito control. Among these interesting devices are the photonic traps. We have carried out nightly captures of mosquitoes on human baits in the presence and absence of the device. These captures were made during the rainy season in the localities of Zogbadjè and Mènontin. The captures were made under the same atmospheric conditions at the same locations at 5-day intervals. These captures were made twice per house, indoors and outdoors, with one blank capture without the device and one capture with the device. The captured mosquitoes were identified and classified by genus and their aggressiveness determined by calculating the biting rate. A total of 845 mosquitoes were captured during these captures with 296 mosquitoes captured indoors without the device and 132 mosquitoes with the device present. This represents a decrease of 55.40% in culicidae density. Furthermore, a significant decrease was observed in aggressiveness, from 49 to 22 bites per man per night (b/m/n) with the use of the device. This decrease is even more important for nocturnal species such as Anopheles spp. whose aggressiveness decreased by 90%. The present study confirms the effectiveness of the “Electron go out mosquito small lamp” in reducing Culicidae density and mosquito aggression even in the presence of chemotactic interference. However, this study was limited in time and focused only on the ability of the device to reduce mosquito numbers and did not assess its epidemiological efficacy. It is therefore important to extend the work to examine the influence of the use of this device on population health and the occurrence of mosquito-borne diseases, particularly malaria.展开更多
Here, we have synthesized the silver nanoparticles (AgNPs) by using the soil fungus Aspergillus niger 2587. The results recorded from UV-vis spectrophotometer and transmission electron microscopy (TEM) support the bio...Here, we have synthesized the silver nanoparticles (AgNPs) by using the soil fungus Aspergillus niger 2587. The results recorded from UV-vis spectrophotometer and transmission electron microscopy (TEM) support the biosynthesis and characterization of AgNPs. The synthesized silver nanoparticles have also been tested against the larvae and pupae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The efficacy test was performed at different concentrations for a period of different hours by the probit analysis. The larvae of Cx. quinquefasciatus have shown the 100% mortality to the synthesized AgNPs after 1 h of exposure, while the larvae of An. stephensi and Ae. aegypti were found less susceptible to the synthesized AgNPs. The pupa of Ae. aegypti has shown the efficacy LC50 4, LC90 12 and LC99 19 ppm after 2 h of exposure of the synthesized AgNPs, while, the pupae of Cx. quinquefasciatus and An. stephensi were found less susceptible to the synthesized AgNPs. By this approach, it is suggestive that this rapid synthesis of nanoparticles would be proper for developing a biological process for mosquito control.展开更多
Reduction of mosquito populations will, at least, reduce substantially the transmission of malaria disease. One potential method of achieving this reduction is the environmentally-friendly population control method kn...Reduction of mosquito populations will, at least, reduce substantially the transmission of malaria disease. One potential method of achieving this reduction is the environmentally-friendly population control method known as the Sterile Insect Control (SIT) method. The SIT method has so far not been widely used against insect disease vectors, such as mosquitoes, because of various practical difficulties in rearing, sterilization and distribution of the parasite population. For mosquitoes, male-only release is considered essential since sterile females will bite and so may transmit disease, whereas male mosquitoes do not bite. This work concerns the mathematical modelling of the effectiveness of Sterile Insect Technique for Aedes aegypti mosquitoes, when the female sexual preference is incorporated. We found that for a released value of the sterile male mosquito below 40,000, the wild mosquito population decreases over time while the sterile male mosquito population increases. Therefore, the transmission of malaria and dengue infection declines because the sterile male mosquitoes dominated the environment. We also found that for a released value of the sterile male mosquito above 40,000, the wild mosquito population decreases and the sterile male mosquito population decreases as well. Therefore, if the injection of sterile male mosquitoes is large enough, the environment will be rid of mosquitoes over time. The result also shows that if sexual selection is incorporated into a reaction diffusion system, modelling the spread of Aedes aegypti mosquitoes, the Sterile Insect Technique (SIT) will still be a successful control measure.展开更多
The periodic outbreak of mosquito-borne diseases like dengue fever,zika fever,and yellow fever all over the world highlights the need for effective mosquito control methods targeting the biological system.Due to the l...The periodic outbreak of mosquito-borne diseases like dengue fever,zika fever,and yellow fever all over the world highlights the need for effective mosquito control methods targeting the biological system.Due to the lack of therapeutic measures,preventive treatments or vaccines against pathogens,insecticide resistance eventually lead the research focus towards novel technological applications in mosquito management.Nanomaterials with ovicidal,larvicidal,adulticidal,and repellent properties for controlling mosquito vectors are under research.A literature search was carried out for advancements in nanomaterials,insecticides,and mosquito control in PubMed/MEDLINE,Scopus,Google Scholar,ScienceDirect,and Web of Science.This paper aims to provide insights into various nanomaterials relevant to mosquito-borne diseases,in vivo and in vitro toxicity evaluation against mosquito species,mode of action,effect on non-target organisms,and ecological risks.Organic and inorganic materials that provide controlled release,target delivery,less dosage,prolonged efficacy,a reduction in the use of organic solvents and emulsifiers,and minimum pollution to the environment have already been explored.Indeed,further research on the ecological risk and economic feasibility of nanomaterials in mosquitocidal applications should be done prior to commercialization.展开更多
Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainsta...Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainstay of effective control.But,indiscriminate and rampant use of the chemical insecticides in controlling mosquito vectors,in order to prevent diseases vectored by them,has resulted problems related to the adverse environmental effects for their(insecticides)potential toxicity,high operational cost,community acceptance,and the development of insecticide resistance among the vectors.The factors mentioned above prompted the search for new means of control strategies.Currently,the botanicals(viz.,plant extracts,essential oils and phytochemicals)with mosquitocidal potential展开更多
Objective:To evaluate the entomological impact of chlorpyrifos-methyl,Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.Methods:A Latin square design with 4 replicates wa...Objective:To evaluate the entomological impact of chlorpyrifos-methyl,Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.Methods:A Latin square design with 4 replicates was performed in order to evaluate the efficacy of chlorpyrifosmethyl, Bacillus thuringiensis,and Gambusia affinis on larva.The larvicide was applied at the dosage of 100 mg a.h/ha,Bacillus thuringiensis at the recommended dosage and 10 fishes per m^2 were applied at 1×1 m^2 artificial breeding sites.The larval densities for both anopheline and culicine were counted according to larvae /10 dippers prior and 24 h after application.Results: All three control agents are effective for mosquito density reduction,and the difference between the three agents and the control is significant(P【0.05).There is also significant difference among chlorpyrifos-methyl,Bacillus thuringiensis and Gambusia affinis.Bacillus thuringiensis exhibited more reduction on mosquito larval density than fish and larvicide(P【0.05).Conclusions: Bacillus thuringiensis in comparison with two other agents is the appropriate method for larviciding in the breeding places.Although long term assessing for biological activities as well as monitoring and mapping of resistance is required.展开更多
Dear Editor The mosquitoes Aedes aegypli(I,) and Aedes albopictus (Skuse)(Diptera:Culicidae) are important vectors of dengue fever in tropical and subtropical parts of the world. Chemical control has been considered a...Dear Editor The mosquitoes Aedes aegypli(I,) and Aedes albopictus (Skuse)(Diptera:Culicidae) are important vectors of dengue fever in tropical and subtropical parts of the world. Chemical control has been considered as an effective tool for their management in different areas of the world.However, injudicious use of the chemicals result in environmental pollution,ill effects to humans and other animals,and the development of insecticide resistance,which ultimately limits the efficacy of many insecticides!’].Essential oils can be used for mosquito control with no harmful effects to the ecosystem and non-target organisms.Essentials oils from different plants have been found very展开更多
Objective:Rice fields are dynamic mosquito larval habitats with assemblage of different predator taxa,including the larva of the mosquitoes Lutzia.Entomological surveillance in the ricefields is essential to evaluate ...Objective:Rice fields are dynamic mosquito larval habitats with assemblage of different predator taxa,including the larva of the mosquitoes Lutzia.Entomological surveillance in the ricefields is essential to evaluate the potential of these predators as biological resource to regulate vector mosquito population.In view of this,a survey of ricefields for immatures of different mosquito species including Lutzia was conducted.Methods:Survey of selected ricefields was carried out to evaluate the species composition of mosquitoes.Laboratory evaluation of the immatures of Lutzia mosquitoes was carried out to assess its predation potential using mosquitoes and chironomid as preys.Results:The survey revealed the presence of five mosquito species belonging to the genera Anopheles and Culex and the predatory immatures of the mosquito Lutzia Juscana(Wiedemann,1820).The ratio of prey and predatory larva ranged between 1.46 and 4.78 during the study period,with a significant correlation on the relative abundance of the larval stages of Lt.Juscana and Anopheles and Culex larvae.Under laboratory conditions,a single IV instar larvae of Lt.fuscana was found to consume on an average 5 to 15 equivalent instars of Anopheles sp.and Culex sp.larvae per day depending on its age.The prey consumption reduced with the larval stage approaching pupation.When provided with equal numbers of chironomid and Anopheles or Culex larvae,larva of Lt.fuscana consumed mosquito larvae significantly more compared to chironomids.Conclusion: The survey results and the preliminary study on predation are suggestive of the role of Lt.Juscana in the regulation of vector mosquito populations naturally in the ricefields.Since Lt.Juscana is common in many Asian countries,further studies on bioecology will be helpful to justify their use in mosquito control programme.展开更多
Objective:To determine larvicidal activity of the essential oil,hydrolat and botanical extracts derived from leaves ol Pseudocalymma alliaceum an mosquito larvae of Culex quinquefasciatus.Methods:Groups of twenty lana...Objective:To determine larvicidal activity of the essential oil,hydrolat and botanical extracts derived from leaves ol Pseudocalymma alliaceum an mosquito larvae of Culex quinquefasciatus.Methods:Groups of twenty lanae were used in the larvicidal assays.The mortality,relative growth rate,the larval and pupal duration and viability was estimated.The essential oil was analyzed by solid phase microextraction using gas chromatography coupled to mass spectrometry.Results:Essential oil at 800 ppm showed larvicidal activity at 24 h with lethal values of LC_(50) and LC_(90) of 267.33 and 493.63 ppm.The hvdrolat at 20% and 10% on 2nd stage larvae showed 100%effectiveness after 24 h.The aqueous extract at 10% had a relative growth index of 0.58.while the ethanolic and methanolic extract obtained values of 0.76 and 0.70 and control reached 0.99.Larvae treated with 10% of methanol,ethanol and aqueous extract showed a reduction in larval duration of 5.00,2.20 and 4.35 days;ethanol extract at 1% provoke decrease of 2.40 days in the development and exhibited an increment of 3.30 days when treated with 0.01%.Aqueous,ethanol and methanol extracts at 10%reduced in 6.15,3.42 and 5.57 days pupal development.The main compounds were diallyl disulfide(50.05%),diallyl sulfide(11.77%) and disulfide di-2-propenyl(10.37%).Conclusions:The study demonstrated for the first time,the larvicidal activity of the essential oil and hydrolat of Pseudocalymma alliaceum:aqueous,ethanol and methanol extracts inhibited the normal growth and development of mosquito larvae,prolonging and delaying larval and pupal duration.展开更多
Objective:To determine resistance status of Culex species to different class of insecticides and assess the major anti-mosquito strategies employed by urban households and their possible effects on malaria acquisition...Objective:To determine resistance status of Culex species to different class of insecticides and assess the major anti-mosquito strategies employed by urban households and their possible effects on malaria acquisition.Methods:Structured questionnaires were randomly administered to obtain information on demographic characteristics,measures that people use to prevent mosquito bites and their perception of where mosquitoes breed in their communities.Adult susceptibility assays were also carried out using WHO discriminating dosages of four insecticides from different chemical classes against Culex species.Results:Majority of respondents(54.75%) preferred the use of domestic insecticides in the form of aerosols and coils.Among households that used domestic insecticides,the use of coil was most frequent(62.9%) with a mean(95%CI) of 9.18(8.99,9.37) coils per week.Strong level of pyrethroid-resistance and multiple insecticide resistance in Culex species were also detected in some of the study sites.Conclusions:The excessive use of domestic insecticides and high level of resistance in Culex species observed in the study area has implications for the ITN component of the nation's malaria control program in more subtle ways.People will lose interest in the use of ITN when it fails to protect users from bites of resistant Culex species.Excessive use of domestic insecticides may also select resistance in both malaria vectors and Culex species.On this account we recommend that nuisance mosquitoes must be controlled as part of malaria control programs to improve acceptance and utilization of ITN.展开更多
More than 2 billion people are at risk of malaria,which primarily affects poor populations in tropical and subtropical areas,including Southern Asia.As malaria incidence has been reduced strongly in some parts of ende...More than 2 billion people are at risk of malaria,which primarily affects poor populations in tropical and subtropical areas,including Southern Asia.As malaria incidence has been reduced strongly in some parts of endemic regions by combinations of interventions,including artemisinin-based therapies and insecticide-treated bed nets,a new goal has been established recently by charity foundations which support research on malaria:the worldwide eradication of the pathology.Doing away with control approaches which have been applied for the last 50 years and more focus on elimination objectives will deeply change priorities in the area of malaria treatment,chemoprevention,vector control,vaccine research and health system assessment.In this review,actual knowledge on pathogenesis and pharmacology is discussed,and new drugs, vaccines and insecticides are described.展开更多
文摘In addition to causing discomfort, female mosquitoes introduce disease-carrying viruses and bacteria into the bloodstream of their victims. There are numerous publications describing the uses of sugary mosquito baits with promising results. Without temperature control measures however, these methods are mainly useful for only nectar-feeding insects, including male mosquitoes, because the warmth of the blood is a condition for the females to locate their meals. The efforts required to keep the baits fresh against the natural spoiling process make them less attractive or impractical to implement. These experiments address these issues by using warm baits of water, sugar, boric acid, and antibiotics. Overnight, the general areas became clear of blood-sucking female mosquitoes while in numbers, the harmless males concentrated into the immediate vicinities. Control vs. experiment protocol established no other logical explanation for this phenomenon other than that females were attracted and killed by the bait. As expected, there was no female mosquito’s activity in these areas. There weren’t many left to do the work.
文摘In the context of mosquito control, a plethora of devices have been put on the market. The effectiveness of these devices is not always proven, but some have interesting principles that have the potential to be a good means of mosquito control. Among these interesting devices are the photonic traps. We have carried out nightly captures of mosquitoes on human baits in the presence and absence of the device. These captures were made during the rainy season in the localities of Zogbadjè and Mènontin. The captures were made under the same atmospheric conditions at the same locations at 5-day intervals. These captures were made twice per house, indoors and outdoors, with one blank capture without the device and one capture with the device. The captured mosquitoes were identified and classified by genus and their aggressiveness determined by calculating the biting rate. A total of 845 mosquitoes were captured during these captures with 296 mosquitoes captured indoors without the device and 132 mosquitoes with the device present. This represents a decrease of 55.40% in culicidae density. Furthermore, a significant decrease was observed in aggressiveness, from 49 to 22 bites per man per night (b/m/n) with the use of the device. This decrease is even more important for nocturnal species such as Anopheles spp. whose aggressiveness decreased by 90%. The present study confirms the effectiveness of the “Electron go out mosquito small lamp” in reducing Culicidae density and mosquito aggression even in the presence of chemotactic interference. However, this study was limited in time and focused only on the ability of the device to reduce mosquito numbers and did not assess its epidemiological efficacy. It is therefore important to extend the work to examine the influence of the use of this device on population health and the occurrence of mosquito-borne diseases, particularly malaria.
文摘Here, we have synthesized the silver nanoparticles (AgNPs) by using the soil fungus Aspergillus niger 2587. The results recorded from UV-vis spectrophotometer and transmission electron microscopy (TEM) support the biosynthesis and characterization of AgNPs. The synthesized silver nanoparticles have also been tested against the larvae and pupae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The efficacy test was performed at different concentrations for a period of different hours by the probit analysis. The larvae of Cx. quinquefasciatus have shown the 100% mortality to the synthesized AgNPs after 1 h of exposure, while the larvae of An. stephensi and Ae. aegypti were found less susceptible to the synthesized AgNPs. The pupa of Ae. aegypti has shown the efficacy LC50 4, LC90 12 and LC99 19 ppm after 2 h of exposure of the synthesized AgNPs, while, the pupae of Cx. quinquefasciatus and An. stephensi were found less susceptible to the synthesized AgNPs. By this approach, it is suggestive that this rapid synthesis of nanoparticles would be proper for developing a biological process for mosquito control.
文摘Reduction of mosquito populations will, at least, reduce substantially the transmission of malaria disease. One potential method of achieving this reduction is the environmentally-friendly population control method known as the Sterile Insect Control (SIT) method. The SIT method has so far not been widely used against insect disease vectors, such as mosquitoes, because of various practical difficulties in rearing, sterilization and distribution of the parasite population. For mosquitoes, male-only release is considered essential since sterile females will bite and so may transmit disease, whereas male mosquitoes do not bite. This work concerns the mathematical modelling of the effectiveness of Sterile Insect Technique for Aedes aegypti mosquitoes, when the female sexual preference is incorporated. We found that for a released value of the sterile male mosquito below 40,000, the wild mosquito population decreases over time while the sterile male mosquito population increases. Therefore, the transmission of malaria and dengue infection declines because the sterile male mosquitoes dominated the environment. We also found that for a released value of the sterile male mosquito above 40,000, the wild mosquito population decreases and the sterile male mosquito population decreases as well. Therefore, if the injection of sterile male mosquitoes is large enough, the environment will be rid of mosquitoes over time. The result also shows that if sexual selection is incorporated into a reaction diffusion system, modelling the spread of Aedes aegypti mosquitoes, the Sterile Insect Technique (SIT) will still be a successful control measure.
文摘The periodic outbreak of mosquito-borne diseases like dengue fever,zika fever,and yellow fever all over the world highlights the need for effective mosquito control methods targeting the biological system.Due to the lack of therapeutic measures,preventive treatments or vaccines against pathogens,insecticide resistance eventually lead the research focus towards novel technological applications in mosquito management.Nanomaterials with ovicidal,larvicidal,adulticidal,and repellent properties for controlling mosquito vectors are under research.A literature search was carried out for advancements in nanomaterials,insecticides,and mosquito control in PubMed/MEDLINE,Scopus,Google Scholar,ScienceDirect,and Web of Science.This paper aims to provide insights into various nanomaterials relevant to mosquito-borne diseases,in vivo and in vitro toxicity evaluation against mosquito species,mode of action,effect on non-target organisms,and ecological risks.Organic and inorganic materials that provide controlled release,target delivery,less dosage,prolonged efficacy,a reduction in the use of organic solvents and emulsifiers,and minimum pollution to the environment have already been explored.Indeed,further research on the ecological risk and economic feasibility of nanomaterials in mosquitocidal applications should be done prior to commercialization.
文摘Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainstay of effective control.But,indiscriminate and rampant use of the chemical insecticides in controlling mosquito vectors,in order to prevent diseases vectored by them,has resulted problems related to the adverse environmental effects for their(insecticides)potential toxicity,high operational cost,community acceptance,and the development of insecticide resistance among the vectors.The factors mentioned above prompted the search for new means of control strategies.Currently,the botanicals(viz.,plant extracts,essential oils and phytochemicals)with mosquitocidal potential
文摘Objective:To evaluate the entomological impact of chlorpyrifos-methyl,Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.Methods:A Latin square design with 4 replicates was performed in order to evaluate the efficacy of chlorpyrifosmethyl, Bacillus thuringiensis,and Gambusia affinis on larva.The larvicide was applied at the dosage of 100 mg a.h/ha,Bacillus thuringiensis at the recommended dosage and 10 fishes per m^2 were applied at 1×1 m^2 artificial breeding sites.The larval densities for both anopheline and culicine were counted according to larvae /10 dippers prior and 24 h after application.Results: All three control agents are effective for mosquito density reduction,and the difference between the three agents and the control is significant(P【0.05).There is also significant difference among chlorpyrifos-methyl,Bacillus thuringiensis and Gambusia affinis.Bacillus thuringiensis exhibited more reduction on mosquito larval density than fish and larvicide(P【0.05).Conclusions: Bacillus thuringiensis in comparison with two other agents is the appropriate method for larviciding in the breeding places.Although long term assessing for biological activities as well as monitoring and mapping of resistance is required.
文摘Dear Editor The mosquitoes Aedes aegypli(I,) and Aedes albopictus (Skuse)(Diptera:Culicidae) are important vectors of dengue fever in tropical and subtropical parts of the world. Chemical control has been considered as an effective tool for their management in different areas of the world.However, injudicious use of the chemicals result in environmental pollution,ill effects to humans and other animals,and the development of insecticide resistance,which ultimately limits the efficacy of many insecticides!’].Essential oils can be used for mosquito control with no harmful effects to the ecosystem and non-target organisms.Essentials oils from different plants have been found very
文摘Objective:Rice fields are dynamic mosquito larval habitats with assemblage of different predator taxa,including the larva of the mosquitoes Lutzia.Entomological surveillance in the ricefields is essential to evaluate the potential of these predators as biological resource to regulate vector mosquito population.In view of this,a survey of ricefields for immatures of different mosquito species including Lutzia was conducted.Methods:Survey of selected ricefields was carried out to evaluate the species composition of mosquitoes.Laboratory evaluation of the immatures of Lutzia mosquitoes was carried out to assess its predation potential using mosquitoes and chironomid as preys.Results:The survey revealed the presence of five mosquito species belonging to the genera Anopheles and Culex and the predatory immatures of the mosquito Lutzia Juscana(Wiedemann,1820).The ratio of prey and predatory larva ranged between 1.46 and 4.78 during the study period,with a significant correlation on the relative abundance of the larval stages of Lt.Juscana and Anopheles and Culex larvae.Under laboratory conditions,a single IV instar larvae of Lt.fuscana was found to consume on an average 5 to 15 equivalent instars of Anopheles sp.and Culex sp.larvae per day depending on its age.The prey consumption reduced with the larval stage approaching pupation.When provided with equal numbers of chironomid and Anopheles or Culex larvae,larva of Lt.fuscana consumed mosquito larvae significantly more compared to chironomids.Conclusion: The survey results and the preliminary study on predation are suggestive of the role of Lt.Juscana in the regulation of vector mosquito populations naturally in the ricefields.Since Lt.Juscana is common in many Asian countries,further studies on bioecology will be helpful to justify their use in mosquito control programme.
基金financial support provided by National Polithecnic InstituteNational Council of Science and Technology(CONACYT),Mexico
文摘Objective:To determine larvicidal activity of the essential oil,hydrolat and botanical extracts derived from leaves ol Pseudocalymma alliaceum an mosquito larvae of Culex quinquefasciatus.Methods:Groups of twenty lanae were used in the larvicidal assays.The mortality,relative growth rate,the larval and pupal duration and viability was estimated.The essential oil was analyzed by solid phase microextraction using gas chromatography coupled to mass spectrometry.Results:Essential oil at 800 ppm showed larvicidal activity at 24 h with lethal values of LC_(50) and LC_(90) of 267.33 and 493.63 ppm.The hvdrolat at 20% and 10% on 2nd stage larvae showed 100%effectiveness after 24 h.The aqueous extract at 10% had a relative growth index of 0.58.while the ethanolic and methanolic extract obtained values of 0.76 and 0.70 and control reached 0.99.Larvae treated with 10% of methanol,ethanol and aqueous extract showed a reduction in larval duration of 5.00,2.20 and 4.35 days;ethanol extract at 1% provoke decrease of 2.40 days in the development and exhibited an increment of 3.30 days when treated with 0.01%.Aqueous,ethanol and methanol extracts at 10%reduced in 6.15,3.42 and 5.57 days pupal development.The main compounds were diallyl disulfide(50.05%),diallyl sulfide(11.77%) and disulfide di-2-propenyl(10.37%).Conclusions:The study demonstrated for the first time,the larvicidal activity of the essential oil and hydrolat of Pseudocalymma alliaceum:aqueous,ethanol and methanol extracts inhibited the normal growth and development of mosquito larvae,prolonging and delaying larval and pupal duration.
文摘Objective:To determine resistance status of Culex species to different class of insecticides and assess the major anti-mosquito strategies employed by urban households and their possible effects on malaria acquisition.Methods:Structured questionnaires were randomly administered to obtain information on demographic characteristics,measures that people use to prevent mosquito bites and their perception of where mosquitoes breed in their communities.Adult susceptibility assays were also carried out using WHO discriminating dosages of four insecticides from different chemical classes against Culex species.Results:Majority of respondents(54.75%) preferred the use of domestic insecticides in the form of aerosols and coils.Among households that used domestic insecticides,the use of coil was most frequent(62.9%) with a mean(95%CI) of 9.18(8.99,9.37) coils per week.Strong level of pyrethroid-resistance and multiple insecticide resistance in Culex species were also detected in some of the study sites.Conclusions:The excessive use of domestic insecticides and high level of resistance in Culex species observed in the study area has implications for the ITN component of the nation's malaria control program in more subtle ways.People will lose interest in the use of ITN when it fails to protect users from bites of resistant Culex species.Excessive use of domestic insecticides may also select resistance in both malaria vectors and Culex species.On this account we recommend that nuisance mosquitoes must be controlled as part of malaria control programs to improve acceptance and utilization of ITN.
基金supported by the Compagnia di San Paolo-IMI grants to MP in the context of the Italian Malaria Network
文摘More than 2 billion people are at risk of malaria,which primarily affects poor populations in tropical and subtropical areas,including Southern Asia.As malaria incidence has been reduced strongly in some parts of endemic regions by combinations of interventions,including artemisinin-based therapies and insecticide-treated bed nets,a new goal has been established recently by charity foundations which support research on malaria:the worldwide eradication of the pathology.Doing away with control approaches which have been applied for the last 50 years and more focus on elimination objectives will deeply change priorities in the area of malaria treatment,chemoprevention,vector control,vaccine research and health system assessment.In this review,actual knowledge on pathogenesis and pharmacology is discussed,and new drugs, vaccines and insecticides are described.
