PLANT ALLELOCHEMICALS AND INSEC T PARASITOIDS Effects of Nicotine on Cotesia congregata

Abstract—Parasitoids developing within tobacco homworms or fall army-worms exhibit significant differences in development and survival dependin g on whether their hosts fed on nicotine-free or nicotine-containing diets. The effects of nicotine were more severe on the relatively less adapted parasitoid, H. annulipes than the specialist parasitoid, Cotesia congregata. Labeled al-kaloid originally placed in herbivore diet was incorporated in several para-sitoid tissues. These results suggest that interactions between plant allelo-chemicals and parasitoids should be considered in the development of theory on insect herbivory and plant defense. Key Words—Plant allelochemical, parasitoids, three trophic level interac