Degradation of Insecticides by Esterases of the American Cockroach1

Abstract

At least 14 different bands hydrolyzing alpha-naphthyl acetate were recognized in the homogenate of the American cockroach, periplaneta americana (L.), by using an agar gel electrophoresis technique. Each band was isolated from the agar plate and tested against various substrate esters, including insecticidal organophosphates and a carbamate to characterize its ability to degrade the insecticides and their analogs. At least 3 distinctly different A-type and 2 B-type esterases were active in hydrolyzing toxic phosphates and carbamates in the American cockroach. In all cases each insecticidal ester was hydrolyzed by more than 2 different esterases.