Resistance of Blattella germanica to common used insecticides in Yancheng city

Objective To determine resistance of Blattella germanica to deltamethrin,dichlorvos,propoxur,acephate,high effect cypermethrin in Yancheng city,and develop scientifical and reasonable work of killing cockroaches.Methods Using the method of medicine membrane-touching in 500 ml flask to find out the KT50 of Blattella germanica.Results The resistance index of field collected strains of Blattella germanica to above mentioned insecticides were 0.16,5.43.0.0013,1.13 and 11.03.Blattella germanica in Yancheng city showed high resistance to high effect cypermethrin,middle resistance to dichlorvos,low resistance to acephate and sensitive to deltamethrin and propoxur.Conclusion It is necessary to select appropriate insecticides according to the situation of resistance so as to improve cockroach control effect.