COLLABORATIVE RESEARCH: Tritrophic interactions and the temporal stability of host-use by an oligophagous herbivore

许多动物在觅食时必须在寻找食物的需要和被捕食者自己吃掉的风险之间进行权衡。因此，对于食草动物来说，最好的食物来源或宿主植物可能会波动，因为植物的营养质量和捕食强度都会在时间和空间上变化。这个项目的目标是评估一种常见的蝴蝶--银斑蝶--对一系列植物物种的偏好和表现，这些植物目前被它的毛虫用作食物植物。研究人员将为这些常见的植物建造一个实验园，并测量随着时间的推移，幼年和成鱼在植物之间的存活、生长和繁殖方面的差异。这些数据将被用来构建一个生态模型，预测食用植物对当地弹涂鱼种群的影响。此外，还将对田间毛虫的捕食行为进行观察，以比较不同粮食作物上发现的天敌群落的活动和组成。结合起来，这些方法将提供一种独特的全面的研究，以植物为基础和敌人为基础的衡量一种常见食草动物成功与否的措施的时间变化。更好地了解决定植食性昆虫食性的因素，将有助于设计有效的生物防治战略，将害虫造成的经济损失降至最低。由于研究中的食草动物以几种入侵植物为食，这项研究的结果将对负责保护自然群落完整性的土地管理者有用。对华盛顿特区K-5学校的广泛教育推广将使学生和教师都有机会接触到实践项目，使他们接触到生态学原理、仔细观察的实践和科学方法。教师们将学会在支持科学课程的课堂练习中使用当地的昆虫。

Many animals must balance the need to find food against the risks of being eaten themselves, by predators, when feeding. As a result, the best food source, or host plant, for an herbivore may fluctuate, because both plant nutritional quality and the intensity of predation change in time and space. The goal of this project is to assess the preference and performance of a common butterfly, the Silver-spotted Skipper, on an array of plant species that are currently used by its caterpillars as food plants. The researchers will construct an experimental garden of these common plants and measure differences in survival, growth, and reproduction of juvenile and adult skippers among plants over time. These data will be used to construct an ecological model predicting food plant effects on local populations of skippers. In addition, behavioral observations of predation on caterpillars in the field will be made to compare the activity and composition of the natural enemy communities found on different food plants. In combination, these approaches will provide a uniquely comprehensive investigation of temporal variation in plant-based and enemy-based measures of success in a common herbivore. A better understanding of the factors determining the diets of plant-feeding insects will contribute significantly to the design of effective biological control strategies to minimize economic damage caused by insect pests. Because the herbivore under study feeds on several invasive plants, the results of this research will be useful to land managers charged with protecting the integrity of natural communities. Extensive educational outreach to K-5 schools in the Washington, DC, area will provide both students and teachers access to hands-on projects exposing them to ecological principles, the practice of careful observation, and the scientific method. Teachers will learn to use local insects in classroom exercises that support science curricula.