Laboratory investigations on the effect of selected disinfectants on survival of the cockroaches Blattella germanica (L.).

It was ascertained that lysol 2% and 5% showed the most toxic effect in control of cockroaches in the contact method (23.3% and 95.5% mortality after 24 hours of exposure), and that chloramine 1%, 3% and 5% was the most effective food poison (after 19 days exposure 100% of the insects died). When injecting disinfectant into the body cavity, the cockroaches showed a ten times higher sensibility to formalin and chloramine than to lysol. The use, however, of disinfectant in the contact method (particularly lysol 2%) together with an insecticide based on propoxur, allowed to reduce its dose to a half, what gave better results than the use of an insecticide alone in a normal dose.