[Changes in the activity of enzyme systems of xenobiotic metabolism at different stages of insect development].

The cytochrome P-450 content, activity of microsomal monooxygenases, nonspecific esterases and glutathione S-transferases were studied at different stages of development of the Colorado beetle, cotton bollworm, cabbage butterfly, wax moth from the laboratory and natural populations. The data obtained demonstrate significant species, sexual and age differences in the activity of enzyme systems of insecticide detoxication. The toxic efficiency of insecticides at certain developmental stages depends on the level of activity of the enzyme systems involved in their metabolism. These data are discussed with respect to the problem of insects' sensitivity to insecticides at different developmental stages.