NSF Grant Expands Study of Self-Medicating Caterpillars

Michael Singer, assistant professor of biology, is the recipient of a NSF grant which will enable him to hire a postdoc and undergraduate student to collaboratively research behavior of the woolly bear caterpillar.
Posted 12/07/07
When a woolly bear caterpillar becomes infected with a parasite, it can’t go to a pharmacy for medicine, so it does the next best thing: It eats the leaves of medicinal plants.

This behavior and recognition for the need to self-medicate when ill is at the heart of a new grant from the National Science Foundation (NSF) for a proposal by Michael Singer, assistant professor of biology, titled “Self-medication: function and mechanism in a woolly bear caterpillar.”

The two-year, $314,267 grant will permit Singer to study in more detail this prescient behavior by the woolly bear caterpillars, also known as Grammia geneura.

“All animals have immunological defenses, subject to modification by diet,” Singer says. “Herbivorous animals may be especially prone to self-medicate by ingesting pharmacologically active chemicals found in the plants they eat. This project will allow me to investigate the means of self-medication by the woolly bear caterpillar, and ultimately help us all better understand the links in the behavior and ecology of wild animals to animal health.”

The grant allows Singer to continue a study he initiated a few years ago, the results of which were published in the July 27, 2005 issue of the esteemed scientific journal Nature.

Singer’s study will include distinct segments. It will begin with behavioral experiments that will characterize the dietary choices of experimentally parasitized caterpillars in relation to caterpillars without parasites. Then experimentally parasitized caterpillars will be given different diets to evaluate the role of specific diets in resistance against parasites. Physiological experiments will evaluate the effects of these diets on the caterpillar’s immune response to parasites.

In addition, to analyze the direct effects of caterpillar diet without the immune system, the parasites will be grown in artificial diets that reflect different caterpillar diets. Theory predicts that caterpillars employ two distinct mechanisms of self-medication that vary in their severity of negative side effects.

“We hope to generate some definitive findings by the end of the study, Singer says.

The grant comes at a time when grant funding by the NSF has become extremely competitive and difficult to obtain.

“That Mike has been successful in obtaining NSF funding indicates the very high regard that Mike’s colleagues across the country have for his research and scholarship,” says Janice Naegele, professor and chair of biology. “This recognition in the area of ecology and integrative organismal biology comes early in his career and will have a positive impact on his upcoming case for tenure and promotion at Wesleyan.”

Along with funding Singer’s research, the grant will also pay for a post-doctoral research fellow. In addition, there is funding to hire an undergraduate research assistant during each summer.

“This will allow a student to gain a high quality research experience along with peers in the Hughes and Mellon summer research programs at Wesleyan,” says Singer. “A postdoc will also enhance training of undergraduate and graduate students working in my lab by spending more hands-on time with students in the lab than I can provide as well as by offering a different intellectual perspective than my own.”

By David Pesci, director of Media Relations