Comparative activities of several phenyl carbamate insecticides against the German cockroach, Blattella germanica (L.)

Comparative effects of nine substituted phenyl N-methylcarbamates on German cockroach, Blattella germanica, were studied in laboratory conditions. The topical (LD)_<50> values were determined using female cockroaches, and propoxur was found to be the most toxic. In rapidity of knockdown of the cockroaches tested by the plywood contact method, propoxur was excellent. The (KT)_<50> after the limited time contact with the residues on plywoods was the shortest in Meobal, and propoxur was the next. The residual effect of propoxur estimated from the (KT)_<50> values at 28℃ in 1 week and 3 weeks after treatment was also excellent. Summarizing the data obtained here, propoxur has proved to be a very promising insecticide to control German cockroach, and the other carbamates were far inferior to propoxur.