Resistance of Culex pipiens pallens to four insecticides in Nanyang city

Objective To investigate the resistance of Culex pipiens pallens to four insecticides in Nanyang and provide scientific evidence for its control.Methods The dipping method recommended by WHO was used to assay the media lethal concentration(LC50) of the forth-instar larvae.Results The resistance rates of Culex pipiens pallens to temephos,fenobucard were 1.65,1.33 respectively.The resistance rate to deltamethrin was 25.79 reaching the high level.The resiatance rate to beta-cypermethrin was in medium level of 10.00.Conclusion The result shows that the resistance level of Culex pipiens pallens to deltamethrin and beta-cypermethrin is higher and these insecticides should be used scientifically.