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

许多动物在进食时必须在寻找食物的需要与被捕食者吃掉的风险之间取得平衡。因此，食草动物的最佳食物来源或寄主植物可能会波动，因为植物的营养质量和捕食强度随时间和空间的变化而变化。这个项目的目标是评估一种常见的蝴蝶，银斑Skipper，对一系列植物的偏好和表现，这些植物目前被其毛虫用作食物植物。研究人员将在这些常见植物中建立一个实验花园，并测量不同植物中幼虫和成年虫在生存、生长和繁殖方面的差异。这些数据将用于构建一个生态模型，预测食物植物对当地跳船种群的影响。此外，还将在野外对毛虫的捕食行为进行观察，比较不同食物植物上天敌群落的活动和组成。综合起来，这些方法将提供一个独特的综合调查，以植物为基础和以敌人为基础的时间变化衡量一个常见的食草动物的成功。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策略，以尽量减少害虫造成的经济损失。由于所研究的食草动物以几种入侵植物为食，因此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。在华盛顿特区的K-5学校进行广泛的教育推广，将为学生和教师提供实践项目的机会，使他们了解生态原则、仔细观察的实践和科学方法。教师将学习在支持科学课程的课堂练习中使用当地昆虫。

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.