Mosquitoes are an interesting topic due to their medical importance, as they play an active role in the transmission of many pathogens and parasites, acting as vectors for various pathologies that are deadly to humans...Mosquitoes are an interesting topic due to their medical importance, as they play an active role in the transmission of many pathogens and parasites, acting as vectors for various pathologies that are deadly to humans, such as dengue, yellow fever, chikungunya, West Nile virus, encephalitis and malaria, among many others that are less common. In terms of morbidity and mortality caused by vector-borne diseases, mosquitoes are the most dangerous animals for humanity and, although they also play a role in the ecosystem as a food source for other organisms, their importance for public health cannot be overlooked. As highly efficient vectors, they put more than three billion people at risk, mainly in tropical and subtropical regions as well as in Europe, since heat waves and flooding are becoming more frequent and severe, and summers are getting longer and warmer, accelerating mosquito development, biting rates, and the incubation of the pathogens within their bodies. Female mosquitoes bite to acquire proteins for the development of their ovaries and eggs and, in the process, acquire pathogens and/or parasites from one vertebrate host and transmit them to another, usually after a short period of replication. Three of their four life stages are lived in still freshwater, so it is crucial to understand their range of action when they reach adulthood and leave the water, in order to plan and implement local prevention measures. A set of georeferenced abundance data collected in mainland Portugal over seven years was linked to cartographed water bodies in a geographic information system to estimate the distances at which Culex pipiens s.l. had a significant presence, with criteria based on the size of the catches. The result allows for an estimate of the fly range of those mosquitoes, which can be used to focus countermeasures.展开更多
The cytoplasmic incompatibility in the field population of Culex pipiens complex from China and Japan was studied. The results of the crossing experiments between 11 different strains suggest that some Japanese strain...The cytoplasmic incompatibility in the field population of Culex pipiens complex from China and Japan was studied. The results of the crossing experiments between 11 different strains suggest that some Japanese strains might be possible to be used for control Chinese strains by using male sterile technique, and the heavy infection of wolbachiae in mosquitoes may have some relations with the cytoplasmic incompatibility in the field population of Cx. pipiens complex.展开更多
Objective:To determine the variations in morphological characters of Culex pipiens complex and identify the species complex.Methods:A study was carried out from April to October 2009 in Yazd Province,Iran.This study w...Objective:To determine the variations in morphological characters of Culex pipiens complex and identify the species complex.Methods:A study was carried out from April to October 2009 in Yazd Province,Iran.This study was performed in two randomly selected rural villages in Yazd County using different sampling methods such as larval collection,hand catch,pyrethrum space spray,light trap,and pit shelter collections.The data were analyzed using SPSS software Ver. 16.ANOVA and Tukey’s post-hoc test was used to compare the ratios of the samples.Results: The average of the DV/D ration was 0.090±0.007 and the range was 0-0.33.The average D/V ratio was 1.07±0.02,with maximum 1.6 and minimum 0.6.The costa and subcosta intersection were observed beyond the bifurcation of R2+3 in most of the specimens.The bifurcations of R2+3 and M1+3 veins were not on one direction in all samples.The range of the R-Ceh7R2+3 ratio was 2.42-7.91.The average ratio of cross wing was 2.25±0.04 with a range of 1.36-3.70.Conclusions: More populations of Culex pipiens from different areas of Iran need to be studied to gain complete information about the taxonomy and ecology of the species.展开更多
Objective:To evaluate the larvicidal activity of essential oil of Origanum mtijoruna(Lamiaceae)cultivated in Morocco against Culex pipiens(Diptera:Culicidae).Methods:The analysis and the identification of the various ...Objective:To evaluate the larvicidal activity of essential oil of Origanum mtijoruna(Lamiaceae)cultivated in Morocco against Culex pipiens(Diptera:Culicidae).Methods:The analysis and the identification of the various constituents of essential oil were carried out by gas chromatography coupled with mass spectrometry.Biological test was performed according to a standard methodology inspired by the World Health Organization protocol with slight modification.Results:This oil mainly consisted of monoterpene and sesquiterpenes.The majority compounds are 4-terpinene(28.96%),y-terpinene(18.57%),α-terpinene(12.72%) and sabinene(8.02%).The lethal concentrations(LC_(50) and LC_(90)) measured for the essential oil Origanum majorana,were respectively of the order of 258.71 mg/L and 580.49 mg/L.Conclusions:The results could be useful in search for newer,safer,and more effective natural larvicidal agents.展开更多
Objeclive:To evaluate the larvicidal activity of the tuber extracts isolated from two species of Cyclamen（Cyxltimen mimbile Hildebr.and Cyclamen alpinum Dammann ex.Sprcnger） against Culex pipiens L.（Diptera:Culici...Objeclive:To evaluate the larvicidal activity of the tuber extracts isolated from two species of Cyclamen（Cyxltimen mimbile Hildebr.and Cyclamen alpinum Dammann ex.Sprcnger） against Culex pipiens L.（Diptera:Culicidae）.Methods:Twenty young（first-second） or older（third- fourth） instars of tile Culex pipiens were exposed to various concentrations（100 to I 000 ppm） of the extracts.Mortality was recorded after 12-,24-,48-.72- and 96-h of exposure.Results:We determined that the young larval stages were more susceptible to the extracts in comparison with the older larval stages.A comparison of LC<sub>90</sub> and LC<sub>90</sub> values has shown that Cyclamen mimbile was more active than Cyclamen alpinum.Conclusions:This study is the first to report on the larvicidal activity of the extracts of Cyclamen species against Culex pipiens.More studies are needed to isolate and identify the active components involved,their mode of action,and effects on other mosquito and pest species.展开更多
Using a geographic information system (GIS), the relations between a georeferenced data set of Culex pipiens s.l. collected in Portugal mainland during seven years (2006-2012) and meteorological and physiographic para...Using a geographic information system (GIS), the relations between a georeferenced data set of Culex pipiens s.l. collected in Portugal mainland during seven years (2006-2012) and meteorological and physiographic parameters are evaluated. This work is one of the results of a long-term surveillance program of pernicious insects that act as vectors of various diseases;its focus is on the possibility of prevention that can be achieved with abundance data. The focus on Culex pipiens is justified by its abundance and its competence as a vector for numerous health issues. The cumulative distribution of monthly captures by each meteorological parameter allows to compute thresholds corresponding to mosquito massive presence related to 90% of the captures. Using the weather parameters measured in the network of weather stations across the country, a monthly average of each parameter of interest (temperature, humidity, etc.) is computed and an interpolation of the results is made to produce raster maps corresponding to each month. The previously obtained thresholds are applied to each map, producing spatial masks with the relevant zones for each parameter. The intersection of the various masks for each month shows the most densely populated area of Culex, and the ensemble allows us to observe the evolution of mosquito presence through the critical season, which is from May to October at these latitudes. In parallel, mosquito abundance data are related to physiographic parameters. The relative distribution of female mosquitoes across land cover types in each month allows identifying which classes and seasons are most relevant. Orthometric altitude related to the presence of 90% of the catches shows the limits reached by mosquitoes in each month. The results are applied to the previously obtained climate envelopes, delimiting critical areas where the level of risk of transmission of the pathogens for which Culex pipiens is a competent vector is high and countermeasures should be concentrated, allowing its planning, and targeting on a monthly basis. The described procedure can be used with other relevant vectors in any region of the world, whenever abundance data is available.展开更多
In the cities of Algeria, Culex pipiens L. (Diptera: Culicidae) is the mosquito which presents most interest because of its wide geographical distribution and of its abundance which engender a strong nuisance. Besides...In the cities of Algeria, Culex pipiens L. (Diptera: Culicidae) is the mosquito which presents most interest because of its wide geographical distribution and of its abundance which engender a strong nuisance. Besides, its role of vector of the virus West Nile arouses a particular interest in the Mediterranean Basin. These insects are generally controlled by conventional insecticides for the greater part, chemicals which cause in the long term side effects (effects on the not aimed bodies and the resistance of the aimed species). A research for the effect of the bioinsecticide Bacillus thuringiensis (granulated commercial shape in 200 IUT1/mg) was realized on préimaginales populations of the artificial deposits sites (taken directly of them natural the deposits sites) and cleansed populations (stemming from a breeding) having never been handled previously, taking into account local weather and physico-chemical conditions. Analyses of variance, allowed to determine the combined effect of the factor measure and of the factor time which by increasing, increase the efficiency of the product. The results of the rates of mortalities registered after treatment allowed to loosen the DL50 and the DL90 for every embryonic stage. From the results, we estimated the degree of sensibility of the larva populations of Culex pipiens which have proved heterogeneous in partial tolerance in Bacillus thuringiensis for the populations of the sensitive artificial and homogeneous the deposits sites for those stemming from the breeding.展开更多
文摘Mosquitoes are an interesting topic due to their medical importance, as they play an active role in the transmission of many pathogens and parasites, acting as vectors for various pathologies that are deadly to humans, such as dengue, yellow fever, chikungunya, West Nile virus, encephalitis and malaria, among many others that are less common. In terms of morbidity and mortality caused by vector-borne diseases, mosquitoes are the most dangerous animals for humanity and, although they also play a role in the ecosystem as a food source for other organisms, their importance for public health cannot be overlooked. As highly efficient vectors, they put more than three billion people at risk, mainly in tropical and subtropical regions as well as in Europe, since heat waves and flooding are becoming more frequent and severe, and summers are getting longer and warmer, accelerating mosquito development, biting rates, and the incubation of the pathogens within their bodies. Female mosquitoes bite to acquire proteins for the development of their ovaries and eggs and, in the process, acquire pathogens and/or parasites from one vertebrate host and transmit them to another, usually after a short period of replication. Three of their four life stages are lived in still freshwater, so it is crucial to understand their range of action when they reach adulthood and leave the water, in order to plan and implement local prevention measures. A set of georeferenced abundance data collected in mainland Portugal over seven years was linked to cartographed water bodies in a geographic information system to estimate the distances at which Culex pipiens s.l. had a significant presence, with criteria based on the size of the catches. The result allows for an estimate of the fly range of those mosquitoes, which can be used to focus countermeasures.
基金This study was supported by the research grant from Chinese Academy of Sciences and Japan Society for the Promotion of Science in 1981.
文摘The cytoplasmic incompatibility in the field population of Culex pipiens complex from China and Japan was studied. The results of the crossing experiments between 11 different strains suggest that some Japanese strains might be possible to be used for control Chinese strains by using male sterile technique, and the heavy infection of wolbachiae in mosquitoes may have some relations with the cytoplasmic incompatibility in the field population of Cx. pipiens complex.
文摘Objective:To determine the variations in morphological characters of Culex pipiens complex and identify the species complex.Methods:A study was carried out from April to October 2009 in Yazd Province,Iran.This study was performed in two randomly selected rural villages in Yazd County using different sampling methods such as larval collection,hand catch,pyrethrum space spray,light trap,and pit shelter collections.The data were analyzed using SPSS software Ver. 16.ANOVA and Tukey’s post-hoc test was used to compare the ratios of the samples.Results: The average of the DV/D ration was 0.090±0.007 and the range was 0-0.33.The average D/V ratio was 1.07±0.02,with maximum 1.6 and minimum 0.6.The costa and subcosta intersection were observed beyond the bifurcation of R2+3 in most of the specimens.The bifurcations of R2+3 and M1+3 veins were not on one direction in all samples.The range of the R-Ceh7R2+3 ratio was 2.42-7.91.The average ratio of cross wing was 2.25±0.04 with a range of 1.36-3.70.Conclusions: More populations of Culex pipiens from different areas of Iran need to be studied to gain complete information about the taxonomy and ecology of the species.
文摘Objective:To evaluate the larvicidal activity of essential oil of Origanum mtijoruna(Lamiaceae)cultivated in Morocco against Culex pipiens(Diptera:Culicidae).Methods:The analysis and the identification of the various constituents of essential oil were carried out by gas chromatography coupled with mass spectrometry.Biological test was performed according to a standard methodology inspired by the World Health Organization protocol with slight modification.Results:This oil mainly consisted of monoterpene and sesquiterpenes.The majority compounds are 4-terpinene(28.96%),y-terpinene(18.57%),α-terpinene(12.72%) and sabinene(8.02%).The lethal concentrations(LC_(50) and LC_(90)) measured for the essential oil Origanum majorana,were respectively of the order of 258.71 mg/L and 580.49 mg/L.Conclusions:The results could be useful in search for newer,safer,and more effective natural larvicidal agents.
基金the Scientific Projects Administration Unit of Akdeniz University.Turkey for providing financial support
文摘Objeclive:To evaluate the larvicidal activity of the tuber extracts isolated from two species of Cyclamen（Cyxltimen mimbile Hildebr.and Cyclamen alpinum Dammann ex.Sprcnger） against Culex pipiens L.（Diptera:Culicidae）.Methods:Twenty young（first-second） or older（third- fourth） instars of tile Culex pipiens were exposed to various concentrations（100 to I 000 ppm） of the extracts.Mortality was recorded after 12-,24-,48-.72- and 96-h of exposure.Results:We determined that the young larval stages were more susceptible to the extracts in comparison with the older larval stages.A comparison of LC<sub>90</sub> and LC<sub>90</sub> values has shown that Cyclamen mimbile was more active than Cyclamen alpinum.Conclusions:This study is the first to report on the larvicidal activity of the extracts of Cyclamen species against Culex pipiens.More studies are needed to isolate and identify the active components involved,their mode of action,and effects on other mosquito and pest species.
文摘Using a geographic information system (GIS), the relations between a georeferenced data set of Culex pipiens s.l. collected in Portugal mainland during seven years (2006-2012) and meteorological and physiographic parameters are evaluated. This work is one of the results of a long-term surveillance program of pernicious insects that act as vectors of various diseases;its focus is on the possibility of prevention that can be achieved with abundance data. The focus on Culex pipiens is justified by its abundance and its competence as a vector for numerous health issues. The cumulative distribution of monthly captures by each meteorological parameter allows to compute thresholds corresponding to mosquito massive presence related to 90% of the captures. Using the weather parameters measured in the network of weather stations across the country, a monthly average of each parameter of interest (temperature, humidity, etc.) is computed and an interpolation of the results is made to produce raster maps corresponding to each month. The previously obtained thresholds are applied to each map, producing spatial masks with the relevant zones for each parameter. The intersection of the various masks for each month shows the most densely populated area of Culex, and the ensemble allows us to observe the evolution of mosquito presence through the critical season, which is from May to October at these latitudes. In parallel, mosquito abundance data are related to physiographic parameters. The relative distribution of female mosquitoes across land cover types in each month allows identifying which classes and seasons are most relevant. Orthometric altitude related to the presence of 90% of the catches shows the limits reached by mosquitoes in each month. The results are applied to the previously obtained climate envelopes, delimiting critical areas where the level of risk of transmission of the pathogens for which Culex pipiens is a competent vector is high and countermeasures should be concentrated, allowing its planning, and targeting on a monthly basis. The described procedure can be used with other relevant vectors in any region of the world, whenever abundance data is available.
文摘In the cities of Algeria, Culex pipiens L. (Diptera: Culicidae) is the mosquito which presents most interest because of its wide geographical distribution and of its abundance which engender a strong nuisance. Besides, its role of vector of the virus West Nile arouses a particular interest in the Mediterranean Basin. These insects are generally controlled by conventional insecticides for the greater part, chemicals which cause in the long term side effects (effects on the not aimed bodies and the resistance of the aimed species). A research for the effect of the bioinsecticide Bacillus thuringiensis (granulated commercial shape in 200 IUT1/mg) was realized on préimaginales populations of the artificial deposits sites (taken directly of them natural the deposits sites) and cleansed populations (stemming from a breeding) having never been handled previously, taking into account local weather and physico-chemical conditions. Analyses of variance, allowed to determine the combined effect of the factor measure and of the factor time which by increasing, increase the efficiency of the product. The results of the rates of mortalities registered after treatment allowed to loosen the DL50 and the DL90 for every embryonic stage. From the results, we estimated the degree of sensibility of the larva populations of Culex pipiens which have proved heterogeneous in partial tolerance in Bacillus thuringiensis for the populations of the sensitive artificial and homogeneous the deposits sites for those stemming from the breeding.
