It has been shown that plant genotype can strongly affect not only individual herbivore performance, but also community composition and ecosystem function. Few studies, however, have addressed how plant genotype affects herbivore population dynamics. In this talk I will introduce a coupled patch model of herbivore dynamics and explore
how the genetic composition of a forest influences herbivore population cycles in particular pest outbreak dynamics.

Specifically, I will show how plant genotype, the relative size of genotypic patches, and the rate of herbivore dispersal between them, affect the frequency, amplitude, and duration of outbreaks. We found that coupling two different genotypes does not necessarily result in an averaging of herbivore dynamics. Instead, depending on the ratio of patch sizes, when dispersal rates are moderate, outbreaks in the two- genotype case may be more or less severe than in forests of either genotype alone.