Grant: Discovery Grants Program - Individual

Beetles effect a staggering economic and social impact on humankind through the destruction of field crops, stored products, and forests.  Conversely, many beetles are beneficial, acting as predators of insect pests and as biological control agents for weeds.  Knowledge gained in the journey to understand coleopteran biochemistry could be exploited to control pest species, or aid in the management of beneficial species.  The biosynthetic pathways used by beetles to produce their pheromones, and the mechanisms by which these pathways are regulated, have been the targets of much interest.  However, most studies have focused on the biochemistry of aggregation pheromone production.  We propose to examine the biochemistry of sex pheromone production in a model system, the yellow mealworm beetle, Tenebrio molitor.  Early studies by other workers established that the production of the female-produced sex pheromone, 4-methylnonanol, is regulated by Juvenile Hormone (JH).  We have elucidated the biosynthetic route to the pheromone, confirmed that 4-methylnonanol production is regulated by JH, and identified one enzyme involved in the biosynthesis of 4-metnhylnonanol that is regulated by JH.  We also discovered that mating induces a temporary decrease in the level of sex pheromone in the female, due at least in part to an inhibition of sex pheromone biosynthesis.  In this proposal, we plan to determine the mechanisms by which JH and mating exert their effects on pheromone levels in female T. molitor.  This information will not only increase our basic knowledge of insect metabolism but, in the long term, an enhanced understanding of the factors that stimulate or inhibit pheromone production might be of practical value in our attempts to develop new strategies for the manipulation of pest populations.