Behavioral and Ecological Constraints Imposed by Plants on Insect Parasitoids: Implications for Biological Control

Interactions involving parasitoids, their herbivore hosts, and the plants on which their hosts are encountered are complex and dynamic. For example, parasitoids use plant stimuli for locating their hosts, but their survival may be adversely affected by plant allelochemicals ingested by their hosts. Generalizing from our investigations involving Cotesia congregata ( Say) ( Hymenoptera: Braconidae), we suggest that under some conditions, populations of insect parasitoids may adapt to specific plants or to the allelochemicals produced by these plants. Adaptations to plants in insect parasitoids can include increased survivorship and fixation of some components of foraging behavior and may be facilitated by postemergence learning. Variation in the ability to tolerate plant allelochemicals among parasitoid populations may be exploited to enhance biological control efforts. (C) 1991 Academic Press, Inc.