Natural Selection on Continuous Reaction Norms: Thermal Sensitivity of Feeding in Pieris Catepillars

对于大多数生物体来说，一个人完成重要任务的能力--进食、生长、移动等--随着个人的体温而变化。 PI将性能和体温之间的关系称为热性能曲线。 性能曲线如何演变？ 自然选择是如何影响野外种群的表现曲线的？ 对于性能曲线上的自然选择来说，不经常暴露在极低或极高的温度下比经常暴露在“良好”的温度下更重要吗？ 拟议的研究解决了这些问题，通过研究热性能曲线的增长和喂养率的卷心菜白色，一种常见的和广泛的蝴蝶物种，饲料的各种本地和农业十字花科植物（包括卷心菜，羽衣甘蓝和相关蔬菜）的毛虫。 PI将在实验室中测量热性能曲线的遗传变异模式，并确定性能曲线的变化如何影响实验羽衣甘蓝花园的生存、世代时间和繁殖力。 通过同时表征田间毛虫体温，PI可以评估温度变化模式如何与生长和摄食的热性能曲线的选择相关。 然后，PI可以通过操纵花园中的温度变化（使用部分遮阳布）并测量热性能曲线上的选择变化来直接测试这种关系。 这些研究将提供在该领域的热性能曲线的选择的第一个研究。 由于白菜白是一种具有异常大的地理范围的农业害虫（例如，它们发生在北美，欧洲，日本和澳大利亚的大部分地区），这些研究也将增加我们对这种广泛分布的害虫物种的温度适应的理解：它如何能够耐受和适应这些不同地理区域的温度范围？

For most organisms, how well an individual performs vital tasks- eating, growing, moving, etc-varies with that individual's body temperature. The PIs' call the relationship between performance and body temperature a thermal performance curve. How do performance curves evolve? How does natural selection act on performance curves for populations in the field? Is infrequent exposure to extreme low or high temperatures more important than frequent exposure to 'good' temperatures for natural selection on performance curves? The proposed research addresses these questions, by studying thermal performance curves for growth and feeding rates of caterpillars of the Cabbage White, a common and widespread butterfly species that feeds on a variety of native and agricultural crucifers (including cabbage, collards and related vegetables). The PIs' will measure patterns of genetic variation in thermal performance curves in the lab, and determine how variation in performance curves affects survival, generation time and fecundity in experimental collard gardens. By simultaneously characterizing caterpillar body temperatures in the field, the PIs can assess how patterns of temperature variation relate to selection on thermal performance curves for growth and feeding. The PIs can then directly test this relationship by manipulating temperature variation (using partial shade cloths) in the garden and measuring the changes in selection on thermal performance curves. These studies will provide the first studies of selection on thermal performance curves in the field. Because Cabbage Whites are an agricultural pest with unusually large geographic range (e.g. they occur throughout most of North America, Europe, Japan and Australia), these studies will also add to our understanding of temperature adaptation in this widespread pest species: How is it able to tolerate and adapt to the wide range of temperatures experienced in these different geographical areas?