Influence of Sesquiterpene Lactones of Vernonia (Compositae) on Oviposition Preferences of Lepidoptera

Abstract

Oviposition preference tests were conducted with 5 spp. of Lepidoptera on 3 spp. of Vernonia (Compositae). Cabbage looper [Trichoplusia ni (Hubner)] exhibited a decided preference for V. gigantea (Walt.) Trel. and V. glauca (L.) Willd., which contain the sesquiterpene lactone glaucolide-A, over V. flaccidifolia Small which lacks this bitter compound. The fall armyworm [Spodoptera frugiperda (J.E. Smith)], southern armyworm [S. eridania (Cramer)] and yellow-striped armyworm [S. ornithogalli Guenee] all laid a significantly greater number of eggs on V. flaccidifolia. Additional oviposition tests, using V. flaccidifolia with glaucolide-A added, demonstrated that this substance influences oviposition preference only in the fall armyworm.