Ethyl acetate extracts of Momordica charantia leaves had significant antifeedant, inhibitive development activity and toxicity on many insect pests In order to explore its insecticidal mechanism on insect, the effect of ethyl acetate extracts of Mcharantia leaves on activities of trehalas, alkaline phosphatase, acid phosphatase, carboxyl esterases and GSH-S-transferase in larvae of the Asian corn borer, Ostrinia furnacalis were determined The results showed that the activities of trehalas, alkaline phosphatase and acid phosphatase in tested larvae by ethyl acetate extracts of Mcharantia leaves were inhibited obviously, the average relative activity of trehalas and alkaline phosphatase were decreased in treatment of 02%, decreased by 323% and 341% from 24 h to 72 h, compared to the controls, respectively; the relative activity of acid phosphatase were decreased by 568 % and 380 % in 48 h and 72 h, compared to the controls; With the concentration 005%-02% of ethyl acetate extracts of Mcharantia leaves, the activity of acid phosphatase was also inhibited significantly The activity of carboxyl esterases was inhibited firstly, then was activited Extract can obviously induce the activity of glutathione-S-transferase The result showed that inhibition of ethyl acetate extracts of Mcharantia leaves to the activities of trehalas,alkaline phosphatase and acid phosphatase of OFurnacalis may be one of its major mechanism of inhibition to insect on growth and development. |