BRC-BIO: Plant-Herbivore Interactions in Novel Communities and Environments

The goal of this research is to explore how insects that eat plants respond when the climate gets hotter and drier, and when their usual food plants become scarce. Earth is going through a rapid transformation, causing plants and animals to move to different places due to changes in temperature and humidity. Sometimes, these organisms are also unintentionally moved around by humans. An important result of these changes is that insects encounter new plant species they are not used to eating, and these plants also face new insect species that can harm them. Insects are a varied group of animals, including crop pests, pollinators, and species that become meals for birds and mammals. So, understanding how insects respond to environmental changes is crucial for creating effective plans to control pests and conserve wildlife and beneficial species of insects. This project will study the Baltimore Checkerspot butterfly, a species that has recently started to feed on a common non-native plant. The project will determine how these insects include new plants in their diet and if feeding on new plants affects their ability to deal with dryer and hotter conditions. Additionally, the project will educate college students and the general public through outdoor displays of living butterflies to promote insect conservation. The proposed work will focus on a butterfly of conservation concern, the Baltimore Checkerspot (Euphydryas phaeton, Drury, Nymphalidae), to investigate whether host shifts 1) affect herbivore exposure to thermal stress and drought, 2) are driven by phenological synchrony between herbivores and host plants, and 3) influence herbivore thermal sensitivity and their ability to respond to environmental stress. This project will integrate information from field surveys, laboratory, and field experiments to determine whether E. phaeton populations inhabiting areas dominated by the native vs. the novel host differ in both their exposure and tolerance to thermal stress and drought. Understanding the ecological trade-offs involved in herbivore host range expansion, and more specifically, the extent to which thermal environment restricts host use is critical as we seek to understand organismal responses to climate change and the dynamics of novel communities. This research will contribute to the understanding of the environmental factors restricting herbivore host shifts and the role of host shifts in the ability of species to respond to climate change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.