Dissertation Research: Ecological Significance of Omnivory: The Role of Phytophagy in the Persistence of Omnivorous Predator-Prey Interactions

小行星9423543 捕食者种群的持久性主要取决于给定环境中捕食者可利用的资源。当资源减少时，捕食者会挨饿或迁移，捕食者的种群不会持续下去。杂食性捕食者，但是，可以逃避饥饿或阻止移民的植物和持久的环境中捕食密度低。当猎物稀少时，随着每一个额外的猎物被吃掉，杂食性捕食者消耗越来越大比例的猎物种群，进一步抑制猎物种群，最终导致猎物的局部灭绝。杂食性捕食者-被捕食者的相互作用已经得到了相当大的理论关注，有许多例子杂食性昆虫分布在不同的类群，但是，没有研究试图确定的重要性，植食性的持久性的杂食性和猎物种群。本论文的研究将探讨植食性在杂食性捕食者大眼瓢虫及其猎物大豆蚜虫种群持续性中的作用。一系列的实验室和田间实验将确定这种虫子是否能通过食用不同质量的植物材料和生命周期的不同阶段在食物供应不足的时期生存下来。 这项研究将解决重要的问题，在捕食者-猎物动态，包括在维持捕食者种群的重要作用，杂食性猎物项目时，稀缺的时期。此外，这项研究将直接应用于生物防治大豆上的蚜虫害虫，以及控制剂而不是蚜虫对大豆造成的潜在损害。

9423543 Denno The persistence of predator populations is primarily determined by the resources available to the predator in a given environment. When resources decline, predators starve or emigrate and predator populations do not persist. Omnivorous predators, however, can escape starvation or preclude emigration by feeding on plants and persist in environments with low prey densities. When prey are scarce, with each additional prey item eaten, the omnivorous predator consumes an increasingly larger proportion of the prey population, further suppressing the prey population and ultimately resulting in the local extinction of the prey. Omnivorous predator-prey interactions have received considerable theoretical attention and there are numerous examples of omnivorous insects distributed among diverse taxa, however, no study has attempted to determine the importance of phytophagy in the persistence of both omnivore and prey populations. This dissertation research will examine the role of phytophagy in the population persistence of the omnivorous predator, the big-eyed bug, and its aphid prey, a significant pest on soybeans. A series of laboratory and field experiments will determine if the bug can survive periods of low food availability by eating different quality of plant material and different stages in the life cycle. This research will address important issues in predator-prey dynamics including the vital role of omnivory in maintaining predator populations during periods when prey items are scarce. In addition, this research will have direct applications related to biological control of aphid pests on soybeans, and the potential damage to soy beans caused by the control agent, rather than the aphid.