RUI: Interactions of Natural Enemy Impact and Host Plan Genotype on Herbivore Survival

植食性昆虫-植物相互作用研究中的一个中心问题是：什么因素导致植食性昆虫密度的变化和种群中同种寄主植物之间的存活率？虽然有许多可能的机制，但以往的工作强烈表明寄主植物抗性的变化和敌人的影响是重要的。理论和经验证据表明，在植物-食草动物系统中，植物抗性和植物之间可变的敌人影响之间的相互作用可能是常见的和重要的。三个层次交互作用的概念和敌人影响假说提出了植物抗性和敌人影响之间相互作用的三条主要途径。本研究的主要目的是确定寄主植物基因与天敌相互作用的这些途径在该系统中的相对重要性。这些问题的解答对于发展植物-食草动物-天敌相互作用的理论和理解影响植食性昆虫在同种植物中的种群和群落变异的过程具有重要意义。实验计划将确定：1)对三种食草动物对柳树的抗性的遗传力和相关性，2)不同植物基因型之间对天敌影响的变异及其与植物抗性的相关性，3)植物基因或其他食草动物物种直接或间接影响天敌影响的途径的相对重要性，4)草食动物之间直接和间接竞争相互作用的几种机制的相对重要性。其他实验将研究植物基因型、其他食草动物物种和天敌影响之间相互作用的具体途径的细节。

A central question in the study of insect herbivore-plant interactions is: What are the factors responsible for variation in herbivore density and surviorship among conspecific host plants in a population? Although there are many possible mechanisms, variation in host plant resistance and in enemy impact are strongly suggested as important by previous work. Theory and empirical evidence suggests that interactions between plant resistance and variable enemy impact among plants may be common and important in plant-herbivore systems. The concept of three tophic level interactions and the enemy impact hypothesis pose three main pathways of interactions between plant resistance and enemy impact. The main goal of this research is to determine the relative importance of these pathways of interaction between host plant genotype and natural enemy impact in this system. Answers to these questions are important to the development of theory of plant-herbivore-natural enemy interactions and to understanding the processes that influence population and community variation of herbivorous insects among conspecific plants. The experimental program will determine: 1) the heritability and correlation of resistances to three herbivores on willow, 2) the presence of variation in enemy impact among plant genotypes and its correlation with plant resistance, 3) the relative importance of pathways by which plant genotype or other herbivore species directly or indirectly affect enemy impact, and 4) the relative importance of several mechanisms of direct and indirect competitive interactions between herbivores. Other experiments will examine details of specific pathways of interaction between plant genotype, other herbivore species, and natural enemy impact.