[Enzymatic systems of insecticide detoxication in a population of Colorado beetles resistant to permethrin].

The activity of enzymes providing for permetrin detoxication in the imago resistant natural population of the Colorado potato beetle Leptinotarsa decemlineata was studied with the view of elucidating the biochemical mechanisms of resistance to the insecticide. It was demonstrated that the activity of the main enzymes of insect detoxication, i.e., microsomal monooxygenases, nonspecific esterases and glutathione-S-transferases in the permetrin-resistant population of L-decemlineata is enhanced as compared with the permetrin-sensitive population. It was demonstrated that the inhibitors of microsomal monooxygenases, piperonyl butoxide, and of nonspecific esterases, butifos, significantly increase the sensitivity of the resistant population to permetrin. The experimental results suggest that the activity of microsomal monooxygenases and nonspecific esterases is the main factor which determines the resistance of the Colorado potato beetle to permetrin.