Dissertation Research: The Ecological and Evolutionary Significance of Interaction Modification in Ant-phorid Interactions

0104946-D·费纳和爱德华·勒布鲁恩决定哪些物种生活在特定地区的因素，以及这些物种的相对丰富度，人们只了解了一部分。我们的许多知识都来自于研究相互作用的物种对。间接效应是第二类物种相互作用，其中一个物种通过与第三个物种的相互作用影响第二个物种，也可以影响群落结构。蜂群寄生工蚁改变了被蜂群攻击的蚂蚁物种与其他蚂蚁物种之间竞争性相互作用的结果。寄生的结果是，通常会输给被寄生物种的物种获胜。竞争相互作用结果的这种变化构成了一种间接影响，潜在地对竞争蚂蚁群落的结构产生强烈影响。初步调查已经揭示了与这一过程有关的其他间接影响。这项拟议的研究将在亚利桑那州东南部进行，将量化寄生蜂群对寄主蚂蚁的间接影响，并确定间接影响如何改变竞争蚂蚁之间相互作用的结果。其目标是：1)量化寄生对寄主蚂蚁与非寄生物种竞争能力的影响；2)确定竞争对手是否受益于寄生所导致的寄主失去的食物资源；3)检验预测寄生将在多大程度上改变竞争互动结果的理论的有效性。这一努力很重要，因为它将提供第一次详细调查，以了解改变物种之间相互作用的间接影响对相互竞争的物种群体的特性和丰富度的影响有多大。它将直接解决这种影响的可预测性。它将扩大我们对当地共存的蚂蚁种群--一个极其重要的生态种群--是如何组装的，以及寄生蜂类如何影响这一过程的理解。最后，它将提高我们预测利用蜂群苍蝇对入侵蚂蚁物种进行生物控制的有效性的能力。

0104946 - D. Feener and Edward LeBrunThe factors that determine which species live in a particular area and the relative abundance of those species are only partially understood. Much of our knowledge is derived from studying pairs of species interacting. Indirect effects, a second category of species interactions in which one species affects a second via its interactions with a third, can also influence community structure. Parasitism of worker ants by phorid flies changes the outcome of competitive interactions between the ant species attacked by the fly and other ant species. The result of parasitism is that the species that would normally lose to the parasitized species wins. This change in the outcome of competitive interactions constitutes an indirect effect that potentially has a strong influence on the structure of the community of competing ants. Preliminary investigation has already revealed additional indirect effects relevant to this process. The proposed research, to be conducted in Southeastern Arizona, will quantify the indirect effects that parasitism by phorid flies has on the host ant and determine how the indirect effects change the outcome of interactions between competing ants. The goals are to: 1) quantify the effect of parasitism on the ability of the host ant to compete with non-parasitized species; 2) determine whether competitors benefit from food resources lost by the host as a result of parasitism; 3) test the validity of a theory predicting how strongly the outcome of competitive interactions will be modified by parasitism. This effort is important because it will provide the first detailed investigation into how strongly indirect effects that modify interactions between species effect the identity and abundance of competing groups of species. It will directly address the predictability of this impact. It will expand our understanding of how locally co-existing groups of ant species, an extremely ecologically important group, are assembled and how phorid parasitoids impact this process. Finally, it will increase our ability to predict the efficacy of using phorid flies in efforts to biologically control invasive species of ants.