Resistance Of Culex Pipiens Pallens Larva To Insecticides In Zhangjiagang City In 2016

Objective Culex Pipiens Pallens are the major main species of domestic mosquitoes in China,and also the important medium of filariasis and encephalitis.Nowadays,chemical insecticide is still one of the significant measures for the prevention and control of mosquitoes.The widespread application of insecticides in pyrethroid,organophosphorus and fluoroformate has led to the occurrence and development of the resistance of Culex pipiens pallens and Culex mosquitoes.Lots of reports indicate that the Culex pipiens pallens and Culex pipiens in different areas has developed different drgrees of resistance to various insecticides.So there is an urgent need to study on the occurrence and development of insecticide resistance.This study objects to field collection of Cx.pipiens pallens and Cx.pipiens quinquefasciatus populations.And detects the resistance of Culex pipiens pallens to five commonly used insecticides,including:deltamethrin,beta-cypermethrin,permethrin,biothion and fenobucarb.The aim is to provide new measures for mosquito control.Methods From 2011 to 2015,10 monitoring sites were selected in the urban area of zhangjiagang city,and the density monitoring of adult mosquitoes was carried out every year from April to November with the method of mosquito inducing lamp.In June 2016,we collected the Culex Pipiens Pallens from east,west,south,north and middle areas of Zhangjiagang suburb.And took back to the laboratory for breeding,tested with WHO standard bioassay.Then calculated the drug resistance of Culex pipiens pallens larvae(LC50)and 95%confidence limit and other statistical indicators.Results From 2011 to 2015,a total of 7,740 mosquitoes of all kinds were caught at each monitoring site in zhangjiagang city.Among them,4,775 culex pipiens pallens,accounting for 61.69%of the total catch.?Culex pipiens pallens developed 6.54,6.17,2.13,65.15 and 8.25 folds resistance respectively to deltamethrin,beta-cypermethrin,permethrin,biothion and fenobucarb.It turns out Culex Pipiens Pallens in Zhangjiagang has developed high resistance to Biothion,but very low to Deltamethrin,beta-cypermethrin,permethrin,and BPMC.Conclusion In conclusion,insecticides should be used wisely according to different resistance levels.We should focus on eliminating the breeding places for mosquitoes to control Culex Pipiens Pallens.We should adhere to the principle of comprehensive management,give priority to the use of physical,biological and environmental prevention methods and reduce the use of chemical methods.Moreover,it' s also necessary to strengthen the resistance surveillance of culex pipiens pallens,and prevent or delay the development of resistance.