Karin Gastreich, Ph.D.
H, O'Rielly Hall
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My primary interests are behavioral biology and tropical ecology. I received my B.A. in biology at Rice University and my Ph.D. in Zoology at the University of Texas at Austin. Most of my studies have focused on the behavioral ecology of arthropods, primarily the Hymenoptera (ants, bees and wasps) and spiders. My current study sites are in Costa Rica, but I have also worked in Venezuela and Texas. I started teaching at Avila University in 2007. Before that, I worked for Duke University and the Organization for Tropical Studies, running a field tropical ecology program in Central America.
At Avila, I teach Introductory Biology, Anatomy and Physiology Lab, Women in Science (with Sherry Schirmer) and Plant Form and Function. I also supervise student research on plant and insect ecology. My students have worked in the Kansas City area as well as at field sites in Costa Rica.
I have a variety hobbies and interests. For example, I have studied many areas of dance, including ballet, modern, jazz, popular Latin dance and flamenco. In addition I write speculative fiction, mostly fantasy. And of course as a biologist, I can’t get enough of outdoor activities like camping, hiking and bicycling.
A Closer Look at My Research
Behavioral biology is a broad field that asks how and why animals make the decisions they make, both from an evolutionary and an ecological perspective. To date, I have conducted research on several topics within this field, including the origin and maintenance of cooperative behavior, mate selection and territoriality, predator-prey interactions and foraging behavior. My study organisms have included social wasps, red wing blackbirds, plant bugs, ants and spiders. Currently most of my work focuses on plant-arthropod interactions.
One of my favorite systems includes the arthropods associated with Piper plants (family Piperaceae) in the tropics. Piper is a very diverse group with more than 8000 species known worldwide. We interact with Piper every day in our kitchens because the plant that produces black pepper belongs to this group.
I work with three wild species of Piper found in the tropical wet forests of Central America. These Piper species are unique from most others because they participate in a mutualism with the small red ant Pheidole bicornis. The Piper ant-plants provide shelter for Pheidole bicornis in the form of hollow petioles and food in the form of tiny lipid bodies. In return the ants remove herbivores, such as caterpillars and small beetles, from the plant.
This system includes a spider, Dipoena schmidti (family Theridiidae), that preys on the ants. Dipoena is in the black widow family. It makes its web at the base of leaves and attacks ants as they try to approach the leaf. In my studies, I’ve found that ants can often detect the spider’s presence before they come into the range of attack. Ants that detect spiders will avoid leaves inhabited by spiders, leaving the plant more vulnerable to herbivores.
There are many questions left to be answered in this system. For example, does the affect of D. schmidti on its ant prey vary between species of Piper? How can three species of plants with such a similar ecological niche coexist in the same forest? Is D. schmidti an ant specialist or will it prey on other arthropods? How might forest fragmentation or other human interventions affect the dynamics of this complex interaction?
Hodson, Amanda, and Karin Rita Gastreich. 2006. Evidence for a novel mutualism in the tropical understory shrub Piper urostachym. Biotropica. 38(1):127-131.
Gastreich, Karin R. and Grant Gentry. 2004. Faunal studies in model Piper systems, with a focus on indirect interactions and novel insect-Piper mutualisms. In Lee Dyer, ed. Piper: A model genus for studies of chemistry, ecology, and evolution. Kluwer Academic/Plenum Publishers. New York.
Gastreich, Karin Rita. 2002. Student perceptions of culture and environment in an international context: A case study of educational camps in Costa Rica. Canadian Journal of Environmental Education 7(1):167-182.
Gastreich, Karin Rita. 2002. Si el norte fuera el sur: A case of squirrel monkey identities. National Center for Case Study Teaching in Science, State University of New York at Buffalo. http://ublib.buffalo.edu/libraries/projects
Gastreich, K.R. 1999. Trait-mediated indirect effects of a Theridiid spider on an ant-plant mutualism. Ecology 80(3):1066-1070.