Sex pheromone production in the housefly has been found to be associated with ovarian development, and further studies have demonstrated that a product from the ovary is essential for stimulating the biosynthesis of sex pheromones. Dr. Blomquist has shown that ecdysteroids from the ovary of the housefly regulate the biosynthesis of the pheromone, and he now wants to examine the regulation of the biosynthetic reactions by the ecdysteroids in more detail. These studies will increase our understanding of the biosynthesis and endocrine regulation of insect sex pheromones, and will provide essential basic information for designing specific techniques for insect control.