9408009 Whitham Recent studies have shown that the genetic and phenotypic variation expressed by in plant hybrid zones has important effects on the distribution of herbivorous insects, fungi, and birds. Hybrid zones can be centers of insect species richness and abundance. This project continues a novel study of the ecological genetics of cottonwoods hybrid zones in Arizona. The investigators are documenting the insect community correlates of plant genotype and making genetic maps of plant resistance and susceptibility traits. They are using synthetic populations and common garden experiments to determine why herbivores accumulate on some hybrids but not others. Finally, they are establishing whether these interactions have affects on other members of the riparian community. This research program is changing our view of the ecological importance of hybrid plants in natural communities. The results of this research have applicability in conservation biology, design of natural reserves, and, potentially, forest and crop pest control.
