evaluation of five local formulated insecticides against german cockroach (blattella germanica l.) in southern iran

background: the german cockroach, blattella germanica l . , is a serious household and public health pest worldwide. con­trol of this species has been very difficult to achieve. toxicity of cypermethrin ec10%, deltamethrin ec5%, diazi­non ec0.5%, lambda-cyhalothrin ec5% and negon® (permethrin+propoxur oil liquid1%) commercial for­mula­tions were investigated against adult males of german cockroaches collected from four hospitals of bandar abbas city, southern iran, during 2006. these insecticides have been used for cockroach con­trol in this city. methods: the tests were carried out only on males by the glass jar contact method recommended by the who. results: maximum mortality rates of 20, 35, 90, and 100% were obtained after one hour contact to label-recom­mended doses of cypermethrin, deltamethrin, lambad-cyhalothrin, diazinon and permethrin+propoxur insecti­cides, respectively. kt 50 results were different from 5.68 min for permethrin+propoxur mixture to 240.37 min for cyper­methrin. german cockroach showed < 80 per cent mortality using three pyrethroid insecticides. conclusion: it seems that the label-recommended concentrations of these insecticides were wrong and lower than who advised for cockroach control. for monitoring of resistance it is recommended to do more tests using the pure ac­tive ingredient of these insecticides.