Resistance of {\sl Blattella germanica} to seven insecticides in Guiyang

Objective To investigate the susceptibility of three field-collected populations of Blattella germanica to seven insecticides,and provide evidence for insecticide application. Methods The method of contact with chemical pesticides in jar was used.Results The average resistance ratio of three field B.germanica strains Guiyang city to seven insecticides,deltamethrin,beta-cypermethrin,γ-cypermethrin,β-cyfluthrin,permethrin,propoxue and DDVP,were(4.20),(6.31),(3.22),(2.31),(18.42),(1.03) and(5.11) folds respectively.All of them had developed high resistance to permethrin with resistance index(13.63)-(22.11).Resistance ratios to deltamethrin,beta-cypermethrin,cypermethrin,cyfluthrin and DDVP were(1.52)-(8.28),but there are very susceptive to propoxue with resistance ratio(0.92)-(1.13).Conclusion Three field-collected population of B.germanica from Guiyang had developed resistance to six insecticides but very susceptive to propoxue.Selecting the suitable insecticides should be paid attention to B.germanica control.