Five related projects are proposed for a leaf mine-oak tree system in which we will attempt to determine whether leaf-to- leaf, tree-to-tree, and tree-species-to-tree species preferences of leaf miners results from differential egg hatching, differential larval performance, differential pupal mortality, or differences in movement of adult moths between trees. Previous research has shown that leaf miners show a distinct preference for different species of tree, different individual trees within a species and different types of leaf within a tree. Such preferences are maintained year after year. Investigations into such factors as leaf abscission, predation, parasitism, and host quality of leaves as measured by amino acid content do not explain preferences of leaf miners for certain leaves or trees. The propose to move miner eggs between leaves, between individual trees, and between tree species. They also plan to move pupae between trees and to mark pupae with heavy metals to determine movement rates of adult moths that we will catch with sticky traps. Such research will greatly increase of knowledge of forest dynamics.