Larvae resistances of Culex pipiens pallens in Jiangsu in 2009.

Objective To survey the larvae resistance of Culex pipiens pallens of Jiangsu in 2009 and provide scientific evidence for selecting control insecticide.Methods Larvae immersion preparation.Results In the 6 cities,the resistance to DDVP was the highest,and that to permethrin was the lowest.In the 7 insecticides,the resistances to deltamethrin,permethrin and temephos were all the highest in Lianyungang,the resistances to beta-cypermethrin and bio-allethrin were the highest in Nanjing and Nantong respectively.The resistances to DDVP and propoxur were the highest in Wuxi.The resistances to permethrin,bio-allethrin,DDVP,propoxur and temphos were the lowest in Nanjing.The resistances to deltamethrin and beta-cypermethrin were the lowest in Huaian and Wuxi respectively.Conclusion The insecticides with low resistances should be used instead of those with high resistances to decrease the development of resistances.