Invasion ecology of non-native forest insects

我的研究调查了入侵的生态基础，以了解为什么一些非本地物种生长并扩展到高密度和破坏性密度，而其他物种则在低密度下持续存在。欧洲和北美之间昆虫入侵者的成功交换是由于它们的森林和动物群组成相似。然而，北美收到更多的成功入侵者比相反。使用三个森林昆虫系统，我将测试在何种程度上非本地物种成为入侵可以解释他们的生活史特征和与新的社会，包括主机树，同源物，生态位共享，和天敌的相互作用。1)为了评估相互入侵的潜力，我们将比较社区的相互作用云杉树皮甲虫，欧洲Ips typographus和北美红翅大小蠹，在各自的本地和入侵范围。我们将测试是否：一）繁殖成功率较高的幼稚宿主物种，二）入侵成功的新范围是青睐的生态位共享同源物和减轻其天敌，和三）有障碍的基因流之间的人口，导致信息素种族，不同的入侵潜力。2)为了评估与当地人的交配相互作用是否可以减缓入侵，我们将测试在非本地棕色云杉长角甲虫（Tetraphus fuscum）和其本地同源物（T。桂翅蕨我们将构建每个物种特有的分子标记库，使我们能够筛选单个的拟步甲。杂交基因型的标本。T.将来自不同欧洲群体的fuscum与加拿大群体进行比较，以确定自入侵以来是否发生了分歧和/或渐渗。3)为了确定营养相互作用是否会影响欧洲和加拿大的入侵潜力，我们将测试i）昆虫-宿主树，ii）昆虫-真菌和iii）真菌-宿主树之间的相互作用是否会影响非本地豚草甲虫，Xylosandrus germanus和Xylosandrus crassiusculus的入侵潜力。这些研究的结果将有助于建立一个社区生态框架，以评估已被截获并可能在加拿大建立的潜在非本地物种的入侵性。

My research investigates the ecological basis of invasiveness to understand why some non-native species grow and expand to high and damaging densities, while others persist at low densities. Successful interchange of insect invaders between Europe and North America occurs due to similarities in their forest and faunal composition. However, North America receives more successful invaders than the reverse. Using three forest insect systems, I will test whether the extent to which non-native species become invasive can be explained by their life history traits and interactions with the novel community, including host trees, congeners, niche-sharers, and natural enemies. 1) To evaluate reciprocal invasion potential, we will compare community interactions of spruce bark beetles, the European Ips typographus and North American Dendroctonus rufipennis, in their respective native and invaded ranges. We will test whether: i) reproductive success is higher on nave host species, ii) invasion success in the new range is favoured by niche-sharing congeners and mitigated by their natural enemies, and iii) there are barriers to gene flow among populations that result in pheromone races that differ in invasion potential. 2) To evaluate whether mating interactions with natives can slow down an invasion, we will test whether interspecific matings occur between the non-native brown spruce longhorn beetle, Tetropium fuscum, and its native congener, T. cinnamopterum. We will construct a library of molecular markers unique to each species that will allow us to screen individual Tetropium spp. specimens for hybrid genotypes in the field. Sequences of T. fuscum from different European populations will be compared to Canadian populations to determine whether divergence and/or introgression have occurred since the invasion. 3) To determine whether trophic interactions influence invasion potential in Europe and Canada, we will test whether interactions between i) insect-host tree, ii) insect-fungus and iii) fungus-host tree affect colonization potential of non-native ambrosia beetles, Xylosandrus germanus and Xylosandrus crassiusculus that differ in their invasiveness. Results from these studies will help build a community ecology framework to evaluate invasiveness of potential non-native species that have been intercepted and may establish in Canada.