Dissertation Research: Control of Insect Populations by Generalist Predators: Impact of Intraguild Predation

9701180建议的研究将探讨多面手地面捕食者--狼蛛(狼蛛科)和地面甲虫(步甲科)--对蔬菜害虫的捕食动态。步行动物和狼蛛消耗着广泛的食草动物物种，它们也相互捕食--这种行为被定义为行内捕食(IGP)。将讨论四个具体问题：(1)狼蛛和步行动物的捕食是否会抑制草食性昆虫的密度？(2)狼蛛和步行动物是否会对其他捕食者的种群产生负面影响？(3)IGP是否限制步行动物和藤壶的种群数量？(4)地面捕食者协会的大小结构是否影响其对草食性昆虫种群的影响？操纵性田间试验将通过控制Lycosids和Carabid迁入围栏菜园，并观察对害虫密度、其他捕食者密度和植物生产力的影响来解决上述问题。野外试验将与实验室喂养试验相辅相成。这项研究将阐明IGP在多大程度上限制了多面手捕食者对食草动物密度的影响。由于这项研究将在农业系统中进行，研究结果将提高对土著多面手捕食者作为生物防治剂的局限性和优势的了解，这将有助于更有效地利用它们进行病虫害综合管理。

9701180 Wise The proposed research will investigate the dynamics of predation by generalist ground predators - wolf spiders (Lycosidae) and ground beetles (Carabidae) - on insect pests of vegetables. Carabids and lycosids, which consume a wide spectrum of herbivore species, also prey on each other - behavior defined as intraguild predation (IGP). Four specific questions will be addressed: (1) Does predation by lycosids and carabids suppress densities of herbivorous insects? (2) Do lycosids and carabids negatively impact populations of other predators? (3) Does IGP limit carabid and lycosid populations? (4) Does the size structure of the ground-predator guild influence its impact on herbivore populations? Manipulative field experiments will address the above questions by controlling immigration of lycosids and carabids into fenced vegetable gardens, and observing effects on pest densities, densities of other predators, and plant productivity. The field experiments will be complemented with laboratory feeding trials. The research will elucidate the extent to which IGP limits the impact of generalist predators on herbivore densities. Since the study will be conducted in an agricultural system, results will improve understanding of the limitations and strengths of indigenous generalist predators as biological control agents, which will contribute to their more effective use in integrated pest management.