Date of Award

5-2011

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Timothy Nuttle, Ph.D.

Second Advisor

Jeffrey Larkin, Ph.D.

Third Advisor

Ellen Yerger, Ph.D.

Abstract

White-tailed deer, Odocoileus virginianus, have induced direct and indirect changes in hardwood forest ecosystems by over-browsing. From 1979 to 1990, deer density was manipulated in regions of Allegheny hardwood forests and ultimately resulted in significant changes in understory composition. Roughly thirty years after the initial research, indirect effects of deer browsing were studied, in particular caterpillar composition, abundance, and diversity on the dominant tree species. I hypothesized that caterpillar abundance on different tree species would reflect deer browsing preferences. Five hundred forty-seven caterpillar specimens were collected; these individuals are representative of 69 Lepidoptera and 10 Hymenoptera species. Caterpillar abundance was standardized to number/kg leaf mass and scaled to caterpillars/hectare. Caterpillar abundance, species richness, and composition were significantly different among the tree species sampled. In comparison to deer, caterpillar species have preferences for different hosts which are dependent upon their degree of specialization and mechanisms for coping with plant defenses.

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