The goal of the proposed research is to test the role of microorganisms in mediating interactions among phytophagous insects, their host plants and their natural enemies. Specifically, the proposed research will determine how endophytic fungi (fungi that produce asymptomatic infections within plant tissues) affect colonization, dispersion, and population dynamics of leafmining and leafchewing insects that feed on a common host plant, Emory oak. Although endophytic fungi are thought to be plant mutualists by deterring other herbivores, accumulating evidence suggests that their effects on phytophagous insects are highly variable. The proposed research will test the direction and magnitude of these effects through a series of field and laboratory experiments and observations. Ecologists have recently recognized that the pervasive effects of microorganisms such as endophytic fungi may alter conventional theories of phytophagous insect - host plant - natural enemy interactions. By rigorously examining the effects of endophytic fungi, the proposed research will test and modify these conventional theories.
