Larval development and adult oviposition of the Oriental tobacco budworm, Heliothis assulta were examined with tobacco leaves sprayed with aqueous or ethanolic extracts from ten selected wild plant species. High larval mortality was observed with extracts from Rhamnus davurice. Persicaria hydroPiPer, Forsythia koreana, Trifolium repens, Styrax japonica, Ginkgo bi/oba, and vilis amurensis. Most of larval mortality occurred during first and second instar, apparently due to antifeeding effects of plant extracts. These extracts also prolonged developmental period of survived larvae and increased the number of larval molts. Oviposition was not affected as much as the larval mortality, but Rhamnus davurice and Styrax jaPonica extracts reduced the number of eggs laid by more than fifty percent.