Mutualism and Antagonism in Multispecies Interactions: Effects of Fungal Associates on Mountain Pine Beetle Fitness

许多树皮甲虫与真菌关系密切。 虽然真菌获得运输到一个新的和其他难以接近的宿主树，相互作用的甲虫的好处一直存在争议。 一种范式认为真菌帮助甲虫杀死树木;然而，许多真菌是非致病性的，许多种类的树皮甲虫是非攻击性的，只攻击死树，但仍然可能与真菌有关。 这个项目的目标是确定小蠹是否从它们的真菌伙伴中获得营养。 利用实验室和实地研究，将确定山松甲虫的两种主要丝状真菌联营体对甲虫适合度的影响。 两种真菌联营公司之间的差异，可以解释的变化，赋予甲虫的好处也将进行调查。 山地松甲虫的周期性爆发在北美西部森林造成重大经济损失。 如果真菌伴生物影响甲虫适合度，这可能会影响昆虫的种群动态。 因此，这项研究不仅有助于了解驱动多物种相互作用和塑造生态群落的因素，而且还将导致更好地了解可能影响主要森林害虫种群动态的因素。 结果将作为实地考察的一部分分发给初中和高中学生，并在树皮甲虫讲习班期间分发给公众。 该项目将支持博士生的论文研究。

Many bark beetles are closely associated with fungi. While the fungi gain transport to a new and otherwise inaccessible host tree, the benefit of the interaction to the beetle has been debated. One paradigm holds that the fungi help the beetle kill the tree; however, many of the fungi are nonpathogenic and many species of bark beetles are nonaggressive and attack only dead trees, yet may still be associated with fungi. The goal of this project is to determine if bark beetles benefit nutritionally from their fungal associates. Using laboratory and field studies, the effects of the two main filamentous fungal associates of mountain pine beetle on beetle fitness will be determined. Differences between the two fungal associates that may explain variation in benefits conferred to the beetle will also be investigated. Periodic outbreaks of mountain pine beetle cause significant economic losses in western North American forests. If fungal associates affect beetle fitness, this could affect the population dynamics of the insect. Thus, this research will not only contribute to the understanding of factors driving multispecies interactions and shaping ecological communities, but will also lead to a greater understanding of factors that may influence the population dynamics of a major forest pest. Results will be disseminated to middle and high school students as part of field trips and to the public during bark beetle workshops. This project will support the dissertation research of a doctoral student.