he endogenous enzymes of protective system including superoxide dismutase(SOD), peroxidase (POD) and catalase (CAT) were found to exist in the larvae ofPieris rapae. The level of SOD activity of the larva was closely correlated with theinstars. After applying deltamethrin to the larvae, the levels of SOD, CAT and PODactivity were found to be higher than that of the control within one hour. Whendeltamethrin was applied to the slug caterpillars Parasa consocia and Thosea pasto-rnata, the SOD and CAT activities were ellhanced gradually with the degree of poiso-ning, but declined rapidly near death. However, the SOD and CAT activities in theslug caterpillars' survived from the deltamethrin treatment were higher than that ofthe control, showing that SOD and CAT activities were correlated with tolerance toinsecticide.
Acta Entomologica Sinica
Pieris rapae-slug caterpillar-superoxide dismutase──cata-Isse──perox idase