EFFECTS OF FIVE NEW COMPOUNDS ON THE LARVAL GROWTH AND DIGESTIVE PHYSIOLOGY OF THE ASIATIC CORN BORER, OSTRINIA FURNACALIS LARVAE

Abstract Five new compounds were tested on the growth and antifeeding activity compared with toosendanin against fifth instar larvae Ostrinia furnacalis. The activities of two proteases, a weak alkaline trypsine‐like enzyme and a chymotrypsin‐like enzyme, in the midgut of Ostrinia furnacalis larvae were also measured. Experimental results suggest that when incorporated into an artificial diet at the concentration of 500mg/kg, the antifeeding activities of toosendanin, C19, C23, C24, C26, C28 were 51.16%, 57.61%, 4.28%, 51.08%, 36.73% and 51.67%, respectively, C19, C24, C28 had no significant difference with toosendanin. At 20mg/kg, the larval growth were remarkably suppressed by C19, C26, C28, the inhibition of C28 was close to toosendanin in 48 h. The two proteases were activated by toosendanin and C28 while they were inhibited in 48 h but activated in 24 h by C19, C24 and C26. In this paper, the related functions and mechanisms were discussed.