Dissertation Research: Intraspecific Competition for Mutualists: Conditional Interactions in a Membracid-Ant Association

虽然互利主义者的竞争概念 在过去的世纪里， 研究提供了直接的实验证据， 其发生。 这种缺失在以下方面尤为明显： 同翅目蚂蚁协会 该研究旨在 来实验性地评估 同翅目聚集体在种内竞争 蚂蚁互助会的服务 操纵性实验 以前证明，膜Publilia modesta （同翅目）受益于蚂蚁蚂蚁照顾 在大多数年份。 一系列实验将评估 假设：（1）蚂蚁是一种有限的资源， （2）蚂蚁的数量倾向于membracids，而不是 仅仅是蚂蚁的存在，就对膜有着重大的影响， 适合度;（3）寄主植物种内和种间变异 品质影响膜蜜露的化学成分 因此，膜竞争蚂蚁的能力， (4)照料蚂蚁通过减少 捕食性蜘蛛（Pellenes sp.）。 这些实验研究将 提供必要的洞察力， 空间可变环境中的相互作用。

While the concept of competition for mutualists has attracted considerable attention during the past century, few studies have provided direct experimental evidence documenting its occurrence. This absence is particularly evident for homopteran-ant associations. The proposed research is designed to experimentally evaluate the hypothesis that neighboring homopteran aggregations intraspecifically compete for the services of an ant mutualist. Manipulative experiments have previously demonstrated that the membracid Publilia modesta (Homoptera) benefits from being tended by the ant Formica occulta in most years. A series of experiments will evaluate the following hypotheses: (1) ants are a limited resource for membracids, (2) the number of ants tending membracids, and not just the presence of ants, has a significant impact on membracid fitness, (3) intra- and interspecific variation in host-plant quality influences the chemical composition of membracid honeydew and therefore the ability of membracids to compete for ants, and (4) tending ants benefit membracids by reducing the impact of predatory spiders (Pellenes sp.). Such experimental studies will provide needed insight into the dynamics of mutualistic interaction in spatially-variable environments.