Evolution of Mating Communication in Moths: Role of Male Courtship Pheromones

North Carolina State University, Raleigh NC

Investigators

Abstract

The overall goal of this project is to understand male-female communication in animals by integrating mechanistic research at the biochemical-genetic-behavioral levels with experimental and observational research in the field, and with research that addresses evolutionary questions. This project will elucidate the chemical structures of signal molecules and blends (pheromones) used in moth mating communication, quantify behaviors elicited by these chemicals, uncover mechanisms of pheromone production and reception, and identify genes that underlie all these processes. This project will lead to a better understanding of the evolution of pheromone blends in females and response profiles in males and females among populations and across closely related species. Because many moth species are important pests in agricultural crops, forests and stored grains, this research has practical significance for society through the discovery of new tools for ecologically based pest control. This project will train a postdoctoral researcher and a graduate student in a multidisciplinary environment that includes quantitative analysis of behavior, chemical ecology, neuroscience and genetics. A unique feature of this project is the collaboration with the University of Amsterdam in the Netherlands and the Max Planck Institute of Chemical Ecology in Germany, which will offer the postdoctoral researcher and graduate student unique training in evolutionary, chemical, and molecular biology in a collaborative international setting. The project will recruit and train undergraduates from underrepresented demographics from North Carolina State University and nearby Historically Black Universities. It will develop outreach programs, including hands-on interactive exercises and discussions in biodiversity, animal behavior and evolutionary biology. Finally, trainees in this project will participate in public education and engagement events, including BugFest (the largest STEM education program in the US with ~35,000 participants annually), Science Cafés, the Science of Attraction (300 participants in 2014), and other public education programs. Three major questions in animal sexual communication motivate this project: 1) What features of close-range male sexual signals affect female choice; 2) What information do components of the male's complex signal convey to the female; and 3) Is the production of male sexual signals biochemically and genetically linked to production of female signals. Answers to these questions are critical not only for understanding the roles of reciprocal signaling and mate choice in the evolution of sexual communication systems in animals, but will also lead to a better understanding of how the evolution of mating preferences can lead to reproductive isolation among populations, and ultimately to the origin of new species. Researchers have largely ignored close-range courtship behavior by male moths, including the release of close-range sex pheromones, female assessment of the male pheromone, preference, and ultimately acceptance or rejection of the male. This project is based on the recent discovery of novel compounds in the male pheromone gland, some of which share biosynthetic origins with female-produced pheromones, while others are chemically unrelated and may be sequestered from larval and adult food. This dual chemistry can provide females with a dual assessment of the male's ability to (a) de novo biosynthesize pheromone compounds similar to hers, and (b) acquire essential nutrients, and grow on a well-defended plant. This project integrates insect mate choice with insect-plant interaction strategies and investigates the new male compounds as a novel class of sexual signaling molecules in insects.