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。它是合成杀虫剂的一种可行和可持续的替代品。我的研究旨在确定在农业生态系统中发现的节肢动物群落内多物种相互作用的一些主导生态学原理和机制。从应用的角度来看，这项研究是必要的，因为天敌之间的负面相互作用可能会危及生物防治计划的有效性。本项目将解决与公会内相互作用(即具有相同资源的同一营养级别的物种之间的相互作用)和寄生蜂对寄主行为的操纵有关的基本和应用问题。利用分子生态学和行为生态学的方法，我希望确定和量化决定大豆田捕食者种类之间以及捕食者和寄生黄蜂之间捕食行为的生态和非生物因素。我的计划的第二个轴与寄生蜂利用寄主进化的策略有关，以及改变的行为可能对生物防治产生的影响。我们最近观察到，寄生黄蜂诱导其瓢虫寄主扮演保镖的角色：寄主靠近寄生蜂蛹，并表现出一系列攻击性/防御性行为，以保护寄生蜂茧免受其天敌的侵害。此外，瓢虫通常会从寄生中恢复过来。我打算回答三个关于主持人行为操纵的重要问题。首先，寄生在多大程度上损害了瓢虫的健康？其次，自然界中是否有大量的瓢虫从寄生中恢复过来？最后，从应用的角度来看，在田间条件下，寄生的瓢虫与未寄生的同种昆虫具有本质上相同的调节蚜虫种群的能力吗？

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?