INSECTICIDAL ACTIVITY OF AGLAIA-ODORATA EXTRACT AND THE ACTIVE PRINCIPLE, ROCAGLAMIDE, TO THE EUROPEAN CORN-BORER, OSTRINIA-NUBILALIS HUBN (LEP, PYRALIDAE)

A standardized twig extract of the Asian shrub, Aglaia odorata Lour. ( Meliaceae), and rocaglamide, a purified active principle of the extrac t, were evaluated for potential to control the European corn borer (Os trinia nubilalis Hubn.), via incorporation into meridic diet fed to la rvae. Life cycle bioassays using the extract revealed that it inhibite d larval growth at all concentrations tested (12.5-100 p.p.m./fresh wt .) and delayed mean time to pupation from 24.1 days (control) to 83.8 days (50 ppm). Other effects include reduced pupal and adult weights a nd an increase in the frequency of deformed pupae. Investigation of co nsumption rates and dietary utilization in larvae feeding on diet cont aining the extract suggested that it acts via a combination of antifee dant and postingestive (toxic) actions. Life cycle bioassays using roc aglamide demonstrated that this compound is an extremely potent inhibi tor of larval growth, with concentration dependent activity observed a t dietary concentrations from 0.05-0.02 ppm. Effects at these levels i nclude severe reductions in growth and pupal weight, and increases in larval mortality and time to pupation. Rocaglamide appears to be as, o r even more active, than the very effective botanical pesticide azadra chtin from the neem tree.