LARVICIDAL AND ANTIFEEDING ACTIVITIES OF ORIENTAL MEDICINAL PLANT-EXTRACTS AGAINST 4 SPECIES OF FOREST INSECT PESTS

Methanol extracts from 77 oriental medicinal plant species in 42 famil ies were tested for their larvicidal and antifeeding activities agains t larvae of Lymantria dispar L., Acantholyda posticalis MATSUMURA, Hyp hantria cunea DRURY and Dendrolimus spectabilis BUTLER, using leaf-dip ping method. Insecticidal and antifeeding activities varied with both plant and insect species. The extracts of Leonurus sibiricus leaves, C ynanchum wilfordii roots and Astragalus membranaceus roots revealed bo th potent larvicidal and antifeeding activities against L. dispar. Esp ecially, A. membranaceus extract was highly toxic to A. posticalis lar vae. Strong antifeeding activity against both L. dispar and H. cunea w as obtained from the extract of Jeffersonia dubia roots. As naturally occurring insecticides, these plant-derived materials could be useful as an alternative for synthetic insecticides for managing field popula tions of these forest insect pests.