Investigation on resistance of Blattella germanica against seven kinds of insecticides in different entironment in Wuhan

Objective To evaluate the resistance of Blattella germanica against seven kinds of commonly used insecticides,providing scientific basis for appropriate application of insecticides.Methods The residual contact method was used to determine the resistance.Results The average resistance of seven wild B.germanica strains in Wuhan against beta-cypermethrin,deltamethrin,propoxur,chlorpyrifos,DDVP,cypermethrin,and permethrin was 2.6-7.7,3.3-10.7,1.1-2.0,2.9-3.8,2.5-11.2,3.5-5.3,and 4.0-6.4 times that of susceptible strain,respectively.Conclusion Seven wild B.germanica strains have developed different degrees of resistance to five kinds of insecticides,yet susceptible to propoxur.Domestic strains have developed strong resistance against deltamethrin,and those collected from fair trade markets have been highly resistant to DDVP.