DISSERTATION RESEARCH: Nutrient-mediated Manipulation of Host Feeding Behavior by a Parasitoid

Wesleyan University, Middletown CT

Investigators

Abstract

This project investigates how an animal's nutrient intake affects its interaction with its parasites. Using an experimentally tractable model system of a caterpillar and its parasitic wasp, Dr. Singer and Ms. Bernardo will conduct experiments designed to reveal how the parasitic wasp benefits by manipulating its host caterpillar's highly regulated nutrient intake. The basic scientific value of this research stems from integrating the perspectives of animal nutrition, immunology, and behavioral ecology, while also contributing to scientific knowledge used in pest control in agriculture and forestry. Public outreach impacts will happen through Elementary Schools in Middlesex County, CT, and Ms. Bernardo's position as vice-president of the Connecticut Entomological Society. The school program will highlight the natural history of insects kept in the lab, while the CT Entomological Society program will organize outreach activities for Connecticut residents of all ages and provide opportunities for other students to share their research with the community at an annual Student Symposium. Parasitoids must battle host defenses and alter the behavior and physiology of their hosts to their own benefit. Parasitoid manipulation of host nutrient intake might be a fundamental component of such interactions, yet it has received limited study in the broader field of host-parasite interactions. This research will test alternative functional hypotheses that could explain manipulation of caterpillar host feeding behavior by a parasitoid wasp. Preliminary evidence from this host-parasitoid interaction suggests that host caterpillars exhibit altered nutrient intake when parasitized by the parasitoid wasp, and this change in host feeding behavior benefits the parasitoid. Hypothetically, altering dietary nutrients of the host can have large effects on parasitoid growth performance and host immune function. Consequently, parasitoids could manipulate host nutrient intake so as to maximize the nutrient supply to host tissues eaten by the parasitoid, or to limit nutrients required for maximal host immune function. The researchers propose to manipulate macronutrient ratios in host diets and use techniques employed in the field of ecoimmunology and insect physiology to evaluate these hypothetical mechanisms of nutrient-mediated host manipulation, and their possible interaction. Data from this project will be stored at Wesleyan University and made accessible as published.