Mousseau 9409004 The interactions between insects and the plants upon which they feed and lay eggs are of great interest to both population biologists and agriculture scientists. This study will investigate egg laying behavior, larval growth, and survival of the leaf-mining beetle, Brachys tessellatus (Coleoptera:Buprestidae), known to attack five species of oak trees (Quercus laevis, Q. marilandica, Q. nigra, Q. incana, and Q. margaretta) in the southeastern United States. The relative importance of the genetic and environmental influences on this beetle's preferences for a given tree species will be determined. Similarly, the genetic and environmental basis to variation in larval growth and survival on the different trees will be examined. It is postulated that where a female deposits an egg (w.r.t. tree species) may be the most important determinant of larval success. This study will also test for a correlation between a female's preference and the success of her offspring. The results of this study will provide insights concerning the factors promoting the specialization of an insect on a given plant, which will have bearing on questions relating to insect diet breadth, and host-race formation.