Dissertation Research: Effects of Habitat Complexity and Host Dominance on Ant-Parasitoid Interactions

生境复杂性和寄主优势对拟寄生蜂相互作用的影响项目摘要被捕食或被寄生的物种必须在逃离捕食者/寄主的需求和争夺有限资源之间取得平衡。栖息地的物理属性可能会影响物种平衡这些需求的能力，但这种可能性仍未被探索。该项目的目标是研究栖息地结构复杂性如何改变寄主蚂蚁逃离其专业寄生蜂的能力，同时仍然有效地竞争资源。通过使用在蚂蚁群落中具有不同竞争能力的宿主，我们还将探讨宿主-寄生性相互作用的栖息地复杂性的后果是否取决于宿主的优势水平。实验将在野外的蚁群中实施，使用便携式觅食箱来控制栖息地复杂性（落叶），竞争和寄生水平。栖息地的复杂性为猎物提供了避难所，这样做可以让猎物逃离捕食者/寄生虫，但仍然有效地竞争。然而，在美国西南部常见的火灾和放牧等干扰事件改变了栖息地的复杂性。因此，这种干扰事件有可能通过改变物种相互作用来影响自然群落的组成。这个项目不仅是在保护美墨边境奇瓦瓦沙漠土地的倡议背景下进行的，它还将为美国和墨西哥机构的生物学学生提供宝贵的培训。

EFFECTS OF HABITAT COMPLEXITY AND HOST DOMINANCE ON ANT-PARASITOID INTERACTIONSPROJECT ABSTRACTSpecies that are subject to predation or parasitism must balance the conflicting demands of escaping from their predators/parasites while still competing for limited resources. Physical attributes of habitats may affect the ability of species to balance these demands, but this possibility remains unexplored. The goal of this project is to examine how habitat structural complexity modifies the ability of host ants to escape from their specialist parasitoids while still competing effectively for resources. By using hosts that differ in their competitive ability within the ant community, we will also explore whether consequences of habitat complexity for host-parasitoid interactions depend on host dominance level. Experiments will be implemented on ant colonies in the field using portable foraging bins to manipulate levels of habitat complexity (leaf litter), competition and parasitism. Habitat complexity provides refuge for prey, and in doing so, may allow prey to escape from predators/parasites but still compete effectively. However, disturbance events such as fire and grazing that are common in the Southwestern United States alter habitat complexity. Such disturbance events therefore have the potential to affect the composition of natural communities by modifying species interactions. Not only will this project be conducted in the context of an initiative to preserve Chihuahuan desert lands along the U.S.-Mexican border, it will also provide valuable training for biology students from both U.S. and Mexican institutions.