DISSERTATION RESEARCH: Chemical Mediation of Multi-trophic Interactions: A Test of the Tri-trophic Interactions Hypothesis

昆虫可以带来巨大的益处，也可以带来巨大的危害，对维持重要的生态系统服务至关重要，对农作物的成功至关重要。本项目将通过研究资源、竞争对手和敌人对昆虫动力学的同时影响，加强对昆虫动力学的基本理解。研究结果的应用将同样改善农业和生物多样性的管理。自然种群受一系列复杂因素的控制，包括可获得食物的数量和质量，与其他个体对这些资源的竞争，以及存在的天敌的数量和种类。然而，大多数关于昆虫种群动态的研究，例如，只涉及这些复杂相互作用的成对。本项目基于一个新提出的假说，即三营养相互作用假说，来测试食物质量、饮食宽度和天敌对食草昆虫调节和共存的同时影响。两组实验将利用以植物和人工饲料为食的毛虫来研究植物化学防御如何介导草食-捕食者相互作用和草食动物对寄生虫威胁的免疫反应。通过实验室和实地实验，该项目研究了植物次生代谢物如何调节食草动物在不同寄主植物上的表现，以及这些化合物如何进一步影响食草动物与更高营养水平的相互作用。该项目将通过检查昆虫生活的整个食物网来推进基础生态学和应用生态学。它将改进正在进行的论文研究，从而加强对有才华的、早期职业生涯的女性研究人员的培训和专业知识。野花和蝴蝶的魅力将该项目的教育影响扩展到本科生以及K-12教师和学生。本科生将有机会从事独立的项目，获得研究的实际经验，正在开发的为小学设计的昆虫教育计划将吸引学生的兴趣，并提供刺激的教育材料。

Insects can be tremendously beneficial, enormously harmful, critical to sustain important ecosystem services, and key to the success of agricultural crops. This project will strengthen the fundamental understanding of insect dynamics by examining the simultaneous effects of resources, competitors, and enemies on insect dynamics. Application of the results will similarly improve agriculture and management of biodiversity. Natural populations are controlled by a complex of factors that include the amount and quality of food available, competition with other individuals for these resources, and the number and kinds of natural enemies present. However, most studies of the dynamics of insect populations, for example, address only pairs of these complex interactions. This project relies on a newly developed hypothesis, the Tri-Trophic Interactions Hypothesis, to test the simultaneous effects of food quality, diet breadth, and natural enemies on the regulation and coexistence of insect herbivores. Two sets of experiments will use caterpillars fed on plants and artificial diet to investigate how plant chemical defenses mediate herbivore-predator interactions and herbivore immune response to parasitoid threat. Using both laboratory and field experiments, the project examines how plant secondary metabolites mediate herbivore performance on different host plants and how those compounds further influence herbivore interactions with higher trophic levels. The project will advance both basic and applied ecology by examining the entire food web within which insects live. It will improve an ongoing dissertation research, thereby enhancing the training and expertise of a talented, early career, female researcher. The charismatic appeal of wildflowers and butterflies extends the educational impacts of the project to undergraduate students as well as to K-12 teachers and students. Undergraduate students will have the opportunity to work on independent projects, gaining hands-on experience with research, and an insect education program designed for elementary schools that is under development will capture students' interest and provide stimulating educational materials.