In many moth species communication between adult males and females is conducted in a language of airborne chemical signals (pheromones). Males are not only exquisitely sensitive to the complex odor mixture released by females of their own species but must also discriminate amongst similar signals released by other species. Because precise communication relies upon a close correspondence between the emitted signal and the sensitivity/specificity of the receiver, it is unclear how novel chemical signals might evolve. New female pheromone blends might arise through mutations in the biosynthetic pathway but little is known about how the male olfactory system evolves in response to such changes. This project seeks to understand this phenomenon by examining the genetic underpinnings of male behavioral preferences and olfactory neurobiology. Males created by interbreeding two closely related species of heliothine moth will be flown in a wind tunnel to determine their preference for specific odor blends. By recording from individual neurons on the antenna and in the brains of these males, behavioral preferences will be related to underlying olfactory neurobiology. Finally, in collaboration with another group at North Carolina State University, DNA analysis of individual males will be performed to determine the genetic basis for these characters, ultimately leading to identification of the genes involved. The results from these studies will provide insights into both the evolution of chemical communication and, because widely divergent animals are thought to process olfactory information in similar ways, the neural mechanisms employed by the brain to code and discriminate different smells. In addition, one of the moth species to be used in the proposed research is a notorious agricultural pest and some findings might lead to novel strategies for pest control. The integrative nature of the proposed research will enhance the intellectual horizons of the personnel involved and will provide excellent opportunities for undergraduate, graduate and postdoctoral trainees to be involved in a broad-based, collaborative research project
