WPC> 2 B V T W Courier 10 pitch c z N x x x , x @ ; HP Laserjet (25-in-one, Network) HPLASEII.PRS X t 4 P RN h 0 IS 2 4 < #| x 9306795 Bowers The ralative importance of hostplant chemistry and predation in determining foraging patterns of insect herbivores and the degree to which these factors intract are largely unknown. This project will include two series of field experiments, with the expression of hosrplant defensive chemistry (iridoid glycosides and phenylpropanoid glycosides in Plantago lanceolata ) manipulated by using cloned genotypes. the first set of experiments will assess the relative effects of chemical variation in hostplant genotypes versus insect predators on the foraging patterns, growth, defensive chemistry, fecundity and survivorship of insect herbivores, plus evaluate the consequences for the hostplant henotypes and insect predators. It uses hostplant genotypes that vary considerably in their levels of defensive chemistry, four caterpillar species that differ in their ability to handle iridoid glycosides and two different kinds of insect predators (stinkbugs and wasps). A second series of experiments will focus on the behavior, growth rate and survivorship of newly hatched specalist caterpillars determine when they induce defensive chemistry in hostplants. %%% Most work on plant herbivore relatiosnship hjas focused either on hostplant chemistry or on the role of natural enemies in isolation. The current project examines the interactions of these factors. This is inmportant because it elucidates mechamisms that control potential pests of crop or forest plants as well as processes that maintain biological diversity of these systems.
