9514559 Thompson Insects exemplify the diversity of animal behavior in the world around us. Some insects are large enough that we can discover how the individual cells in their nervous systems act to orchestrate their behavior. In this project, the central nervous systems of large male and female grasshoppers will be compared to understqand how females but not males manage to produce a female-only sexual behavior, oviposition. Preliminary work has shown that males have most of the same nerve cells that the female uses in her oviposition behavior. However, for one class of cells the male has many fewer. In this study the structure and function of the "oviposition- like" cells of the male will be investigated, and the cells for which the male is deficient will also be compasred. The significance of this work lies in its contribution to the development of a model system where we can investigate adaptations of the nervous sustem that support specialization of behavior.