Trophic and guild interactions in biological control

生物防治是利用天敌（病原体，捕食者，寄生虫）来抑制害虫种群。它是合成农药的可行和可持续的替代品。我的研究旨在确定农业生态系统中节肢动物群落内多物种相互作用的一些主导生态学原则和机制。从应用的角度来看，这项研究是必不可少的，因为天敌之间的负面相互作用可能会损害生物控制计划的有效性。本项目将解决有关的intragguild相互作用（即物种之间的相互作用在同一营养级，共享相同的资源）和主机行为操纵寄生蜂的基本和应用问题。利用分子生态学和行为生态学的方法，我希望确定和量化的生态和非生物因素，确定蚜虫捕食者之间的物种，以及捕食者和寄生蜂在大豆田捕食的发生率。我的计划的第二个轴涉及寄生蜂进化的策略，以利用他们的主机，以及改变行为可能对生物控制的影响。我们最近观察到，一个寄生蜂诱导其coccinellid主机的行为作为一个“保镖”：主机仍然接近寄生蛹，并显示一系列的攻击/防御行为，保护寄生茧对天敌。此外，瓢虫经常从寄生中恢复。我计划回答关于宿主行为操纵的三个重要问题。首先，寄生在多大程度上损害了瓢虫的健康？第二，自然界中有大量从寄生中恢复的瓢虫吗？最后，从应用的角度来看，寄生瓢虫有本质上相同的能力来调节蚜虫种群作为unparasitized同种在田间条件下？

Biological control is the use of natural enemies (pathogens, predators, parasites) to suppress a pest population. It is a viable and sustainable alternative to synthetic pesticides. My research is aimed at identifying some of the governing ecological principles and mechanisms of multispecies interactions within arthropod communities found in agroecosystems. From an applied perspective, this research is essential because negative interactions between natural enemies may compromise the effectiveness of biological control programs. The present project will address fundamental and applied questions related to intraguild interactions (i.e. interactions between species at the same trophic level that share the same resource) and host behavior manipulation by parasitic wasps. Using approaches in molecular ecology and behavioral ecology, I wish to identify and quantify ecological and abiotic factors that determine the incidence of predation among species of aphid predators, as well as between predators and parasitic wasps in soybean fields. A second axis of my program relates to strategies evolved by parasitic wasps to exploit their host, and the impact of altered behaviors may have on biological control. We have recently observed that a parasitic wasp induces its coccinellid host to behave as a "bodyguard": the host remains close to the parasitoid pupae and displays a range of aggressive/defensive behaviors that protect parasitoid cocoon against its natural enemies. Furthermore, the coccinellids often recover from parasitism. I plan to answer three important questions on the host behavior manipulation. First, to what extent does parasitism impair coccinellid fitness? Second, are coccinellids recovering from parasitism abundant in nature? Finally, from an applied perspective, do parasitized coccinellids have intrinsically the same capacity to regulate aphid populations as unparasitized conspecifics under field conditions?