Ecological Factors Promoting Polyphagy in Insect Herbviores

由于大多数毛虫以其环境中的一小部分植物物种为食，因此具有广泛饮食（通才）的物种的存在是神秘的。在这个项目中，一组通才的森林毛虫将被用来测试两个替代假设，他们的广泛的饮食是如何保持：“生态权衡假说”和“风险传播假说”。为了验证这些假设，将在三年内在两个地点的八种无关宿主植物上检查四种毛虫的生存，生长和繁殖。将在多个生命阶段的宿主植物之间比较天敌（捕食者和寄生虫）攻击的风险。此外，还将通过在每个地点对毛虫进行实地普查来量化寄主植物偏好的背景模式，以确定昆虫的偏好是否具有适应性。 这项研究的结果将阐明未解决的争论的重要性，天敌昆虫的饮食宽度的演变。由于大量的经济害虫是通才，发展我们对寄主植物协会如何发展和维持的理解可以帮助长期的生物控制工作。该项目的一个重要方面是编制和实施关于昆虫进化生态学的基础教育单元。此外，该项目还将培养一批生态研究本科生。

Because most caterpillars feed on a very small subset of the plant species in their environment, the existence of species with broad diets (generalists) is enigmatic. In this project, a set of generalist forest caterpillars will be used to test two alternative hypotheses for how their broad diets are maintained: the 'ecological tradeoffs hypothesis' and the 'risk-spreading hypothesis.' To test these hypotheses, the survival, growth, and reproduction of four caterpillar species will be examined on eight unrelated host plant at two sites over three years. The risk of attack from natural enemies (predators and parasites) will be compared among host plants at multiple life stages. In addition, the background pattern of host plant preference will be quantified through field censuses of caterpillars at each site to determine if insect preferences are adaptive. The results of this study will illuminate the unresolved debate over the importance of natural enemies in the evolution of insect diet breadth. Because a large number of economic pests are generalists, developing our understanding of how host plant associations develop and are maintained can aid long-term biological control efforts. An important facet of this project is the development and implementation of an elementary education module on insect evolutionary ecology. In addition, the project will train a team of undergraduates in ecological research.