A Model for Species Interactions: Costs and Benefits of Linked Herbivory/pollination in Datura Wrightii and Manduca Sexta

University Of Arizona, Tucson AZ

Investigators

Abstract

A model for species interactions: Costs and benefits of Linked herbivory/pollination in Datura wrightii and Manduca sexta Bronstein, Judith L. University of Arizona Mutualisms (reciprocally beneficial interactions between species) are critical components of biological systems, yet have received little experimental study. This project will take a physiologically-based field and laboratory approach to studying the costs, benefits, and reciprocal net effects of interactions between the common hawkmoth (Manduca sexta) and the plant upon which it primarily depends in Arizona (Datura wrightii). Like certain other generalist Lepidoptera, M. sexta acts as both a primary pollinator and a damaging herbivore of the same plant species. This study will identify and quantify costs and benefits of the interaction to both partners, via observational and experimental studies. These data will allow exploration of the link between the benefit of pollination and the cost of herbivory experienced by the plant, and the cross-link between the cost of herbivory to the plant and the benefit of consumption to the insect. In establishing the energetic and fitness relationships between Datura and Manduca, this study will both suggest and facilitate future quantitative investigations into mutualisms, the most poorly understood species interaction. Furthermore, these studies will shed light on the general problem of how pollination and herbivory interact to regulate plant fitness, as well as on the physiological ecology of desert plants and animals. This project represents a collaboration among three researchers with distinct backgrounds and areas of expertise, and will foster novel interdisciplinary approaches cutting across plant and animal biology. Manduca sexta is a major agricultural pest, so the results of this project should have significant applied value as well. Undergraduates employed in this project will be recruited from a program at the University of Arizona that actively encourages research opportunities for under-represented groups.