Population and community ecology of the brown spruce longhorn beetle

随着全球贸易的增加，外来入侵森林昆虫已成为北美森林生态和经济的严重干扰因素。祖母绿灰螟（原产于远东）和褐云杉长角甲虫（原产于东欧）是最近在加拿大东部出现的两种杀树昆虫。这些昆虫在其原生范围内不是害虫，但由于缺乏监管控制和允许种群爆炸的新型生态相互作用，导致加拿大树木死亡。我的研究调查了杀死树木的昆虫、它们的宿主树木和天敌的生态和行为，目的是了解地方病种群为何以及如何转变为流行病。我预测，在昆虫的新活动范围内，相互作用的群落的组成将决定外来昆虫物种成为入侵的程度。以褐云杉长角甲虫作为我的研究系统，我将运用理论（数学模型）和经验（实验室和实地实验）的方法来比较加拿大的群落相互作用的性质（即与宿主树、竞争对手和天敌的关系）与甲虫在欧洲本土范围内发生的相互作用。群落结构和功能的研究及其与种群动态的关系将作为预测外来昆虫何时和是否会发生种群爆发的工具。预测外来物种的入侵对于理解问题并找到解决方案至关重要。识别“高影响”入侵者将有助于开发决策支持工具，以减轻加拿大森林中外来害虫的影响。这项研究的结果将引起入侵生态学家、进化生物学家和森林管理者的兴趣。

With increasing global trade, invasive alien forest insects have become agents of severe ecological and economic disturbance in North American forests. The emerald ash borer (native to the Far East) and the brown spruce longhorn beetle (native to Eastern Europe) are two examples of tree-killing insects that have recently established in Eastern Canada. These insects are not pests in their native range but cause tree mortality in Canada as a result of novel ecological interactions that lack regulatory controls and permit population explosions. My research investigates the ecology and behaviour of tree-killing insects, their host trees and natural enemies with the goal of understanding why and how endemic populations transition into epidemics. I predict that the composition of the interacting community in an insect's new range would determine the extent to which an alien insect species becomes invasive. Using the brown spruce longhorn beetle as my study system, I will apply theoretical (mathematical models) and empirical (laboratory and field experiments) approaches to compare the nature of community interactions (i.e. relationship with host trees, competitors and natural enemies) in Canada to interactions that occur in the beetle's native European range. The study of community structure and function and their correlation with population dynamics will serve as predictive tools to determine when and whether an alien insect will undergo a population outbreak. Predicting the invasiveness of alien species is crucial to understanding the problem and finding solutions. Identification of "high impact" invaders will be helpful when developing decision support tools to mitigate the effects of alien pests in Canada's forests. Results from this research will be of interest to invasion ecologists, evolutionary biologists, and forest managers.