Physiological stress is frequently implicated as a cause of forest tree susceptibility to herbivores, and has been hypothesized as a casual factor in outbreaks of the gypsy moth. Despite much speculation, there have been few comprehensive studies seeking to identify a casual relationship. This research program is designed to do so, using the gypsy moth, two important hostplants, and a baculovirus. Oak leaf traits influence gypsy moth growth, reproduction, and resistance to a virus. This project will determine the influence of drought and nutrient stresses on these leaf traits in controlled experiments, and the consequences for aspects of gypsy moth performance likely to influence its population dynamics. This project integrates research by a specialist in oak physiology with that of chemical ecologist already working on this system. This 3-trophic-level study offers promise of understanding causes of pest irruptions, insight into the basis of plant-herbivore interactions, and improved pest control via developing more effective microbial insecticides, population trend predictions, and stand manipulation.
