Date of Defense



Biological Sciences

First Advisor

David N. Karowe

Second Advisor

Steve Kohler

Third Advisor

David Cowan


Phytoestrogens are compounds, found in over 300 plant species, that have moderate estrogenic or anti-estrogenic activity toward mammals. Phytoestrogens such as genistein and daidzein have been the subject of literally thousands of studies addressing their benefit to human health. However, few studies have addressed the reason(s) for the existence of phyoestrogens in plants. In this study, the author tested the hypothesis that plants contain phytoestrogens because they protect plants by decreasing survivorship, growth, and/or fecundity of insect herbivores. The author compared egg-to-pupa and 4th instar performance of gypsy moth caterpillars on artificial diets containing no phytoestrogen, genistein, daidzein, or a combination of genistein and daidzein. Results suggest that phytoestrogens do not decrease survivorship, growth, or fecundity of insect herbivores. Therefore, the author suggests that phytoestrogens exist in plans for other reasons, including as a defense against small mammaliam herbivores and/or pathogens.

Access Setting

Honors Thesis-Campus Only