Influence of coumarin on the enzymatic activity in nymphs of Lipaphis erysimi (Kalt.)

Analysis of 13 enzymes in the second instar nymphs of Lipaphis erysimi, after feeding on coumarin treated plants for 13h, 25h and 37h showed an increase in the activity of glutathione S-transferases, glutathione reductase, O-demethylase, esterases and alkaline phosphatase. On the other hand, the treatment suppressed the activity of NADH oxidase and glutathione peroxidase. The remaining enzymes viz., catalase, superoxide dismutase, succinate dehydrogenase and NADH dehydrogenase after showing an initial induction at 13h was suppressed with prolonged treatment. The acid phosphatase activity was not influenced by coumarin treatment.