Resistance of Culex pipiens pallens larva to insecticides in Nantong city

Objective To investigate the resistance of Culex pipiens pallens larva in Nantong city to four kinds of insecticides and provide scientific evidence for application of the insecticides. Methods Distinguishing dosage method was used to test the resistance of Culex pipiens pallens larva to four kinds of insecticides.Results Culex pipiens pallens larva from Nantong city had developed resistance in different level to the insecticides: strong resistance to DDVP,medium resistance to Deltamethrin and weak resistance to Cypermethrin and Permethrin. Conclusion The resistances of Culex pipiens pallens larva had been developed for the long time usage of insecticides.It was necessary to apply insecticides scientifically according to the surveillance results.