Organisms have finite amounts of energy to use for growth, maintenance, survival and reproduction. Allocation of energy to any one of these functions reduces the amount available for any of the other functions. Such tradeoffs in energy allocation lie at the foundation of any organism's ecological and evolutionary success as it directly affects an organism's ability to produce offspring. Tradeoffs are fluid, constantly changing with the ecological conditions encountered. Knowledge of the physiological priorities that govern these allocation decisions within an individual is essential for achieving a deeper understanding of constraints or limits on tradeoffs. An individual-level understanding of energy allocation strategies is remarkably rare. This study will examine the functional physiology that prioritizes the energy allocation tradeoff between flight and fecundity, two traits with high-energy demand, in the hawkmoth Manduca sexta (Sphingidae). An innovative approach that combines state of the art respirometry and laser carbon stable isotope analyzer systems will, for the first time, address the functional physiology of this significant tradeoff at the level of the individual in a way that has not previously been possible. This project will combine experiments in nutrient acquisition and allocation, metabolism and stable isotopes into one integrative study in ecological physiology, all in a realistic ecological context. The conceptual breadth of this study will generate integrative research training for a postdoc, and graduate and undergraduate students. In addition, this project will support and enhance Insect Discovery, an existing outreach program that reaches over 2000 elementary school children annually with hands-on, inquiry-based, STEM outreach that meets Arizona State Science Standards.
