Mosquito population density and seasonality based on surveillance analysis in Yancheng,Jiangsu Province,China,2016-2023
Objective To investigate the species composition,density,and seasonal fluctuation of mosquitoes in Yancheng,Jiangsu Province,China,so as to provide a scientific basis for developing effective mosquito control measures and forecasting and early warning of mosquito-borne diseases.Methods Mosquito density was monitored by using the lamp trapping method in five types of habitats(urban residential areas,parks,hospitals,farmers'houses,and livestock sheds)in Yancheng.The species composition,population density,and seasonal fluctuation of mosquitoes were analyzed.With SPSS 20.0 software,the Chi-square test was performed on the mosquito species composition ratios of different years and different habitats,analysis of variance was performed for different years,different species,and different habitats of mosquito densities,and trend analysis was performed for different years and different species of mosquito densities.Results From 2016 to 2023,a total of 132 432 female mosquitoes were caught in Yancheng,with an average density of 13.59 mosquitoes/light·night.Culex pipiens pallens/quinquefasciatus,Anopheles sinensis,and Cx.tritaeniorhynchus were the top three mosquito species,accounting for 68.62%,13.95%,and 12.09%of the total catches,respectively.There was a significant difference in the composition of mosquito species between different years(χ2=9 026.399,P<0.001).Mosquito density and trend changes differed significantly in different mosquito species(both P<0.001).By habitat,the highest mosquito density was in livestock sheds(28.37 mosquitoes/light·night),while the lowest mosquito density was in hospitals(7.84 mosquitoes/light·night),with significant differences in the species composition ratio and density of mosquitoes between habitats(both P<0.001).Seasonal fluctuations in mosquito density showed unimodal distributions for all habitats and for all species,peaking during June and September.Conclusions Cx.pipiens pallens/quinquefasciatus,An.sinensis,and Cx.tritaeniorhynchus are the dominant species in Yancheng.Livestock sheds and farmers'houses are the key places and June to September is the key time for mosquito control.Specific mosquito control measures should be taken based on the population distribution,density change,and seasonal fluctuation of mosquitoes.