Role of plant secondary compounds in invasion biology of an insect herbivore in novel habitats

短叶松是加拿大北方森林的主要树种，为许多植物和动物物种提供基本服务。然而，它的存在受到了入侵的山松甲虫的威胁，因为它已经杀死了数百万公顷的历史宿主树木，主要是北美西部的黑松，最近入侵了北方阿尔伯塔（加拿大）的杰克松森林的西部。在其历史范围内，山松甲虫与黑松有着悠久的共同进化历史，并已适应利用其次生化合物。然而，目前尚不清楚短叶松和黑松对甲虫的易感性是否不同，因为这两个物种在可能影响宿主树木-甲虫相互作用的次级化合物的组成方面有所不同。在我的申请中，我提出了测试两套目标，针对两个不同方面的山松甲虫入侵动力学在短叶松森林。研究1将整合杰克松抗寄生植物病原体，矮槲寄生，和山松甲虫及其共生真菌病原体的生化和生理机制的知识，部分，它们在不同的时间和空间尺度上的资源可用性的关系。研究2将重点关注多代山松甲虫在短叶松上产生的化学通讯信号（信息素）的变化，因为植物次生化合物是树皮甲虫在宿主树上产生和聚集信息素所必需的。从这些研究中得到的信息将是重要的山松甲虫入侵动态和成功的加拿大短叶松森林的基本和应用的理解。研究1将推进植物防御理论，同时增加对调节病原体-草食动物关系和昆虫爆发的因素的理解。该项目也有重要的应用影响：实现更好地了解的生理和生化过程，影响树主机病原体昆虫相互作用的结果可能会指导战略，以提高树的性能在最佳和次优环境中，通过造林处方和遗传选择。* 研究2的结果将确定雄性和雌性山松甲虫是否可以在新的宿主系统中保持化学通讯。同样，树皮甲虫攻击是否同步成功地殖民和杀死短叶松树可能是重要的，以确定在新的生态系统中的山松甲虫的爆发动力学。从实践的角度来看，这些结果将有助于开发有吸引力的诱饵（诱饵），以监测甚至控制新的短叶松森林中的山松甲虫种群。

Jack pine is a dominant tree species in the Canadian boreal forest, providing essential services for a number of plant and animal species. However, its existence has been threatened by the invasive mountain pine beetle as it has killed millions of hectares of historical host trees, mainly lodgepole pine in Western North America during the last outbreak and recently invaded the western extend of jack pine forests in northern Alberta (Canada). Within its historical range, mountain pine beetle shares a long co-evolutionary history with lodgepole pine and has adapted to utilize its secondary compounds. However, it is unknown whether jack pine and lodgepole pine differ in their susceptibility to beetles as both species vary with respect to the composition of secondary compounds which could affect host tree-beetle interactions.***In my application, I proposed to test two sets of objectives targeting two different aspects of mountain pine beetle invasion dynamics in the jack pine forests. Study 1 will integrate knowledge of biochemical and physiological mechanisms of jack pine resistance to a parasitic plant pathogen, dwarf mistletoe, and the mountain pine beetle and its symbiotic fungal pathogen and, in part, their relationship to the resource availability over different temporal and spatial scales. Study 2 will focus on the variation in chemical communication signals (pheromones) produced by the mountain pine beetle on jack pine across multiple generations as plant secondary compounds are required for pheromone production and aggregation by the bark beetles on the host trees.***Information resulting from these studies will be important for both basic and applied understanding of mountain pine beetle invasion dynamics-and success-in the Canadian jack pine forests. Study 1 will advance plant defense theories while increasing understanding of factor regulating pathogen-herbivore relationships and insect outbreaks. This project also has important applied implications: Achieving a better understanding of the physiological and biochemical processes that influence the outcome of tree host-pathogen-insect interactions may guide strategies to improve tree performance in optimal and suboptimal environments through silvicultural prescription and genetic selection. ***Results of the study 2 will determine whether male and female mountain pine beetles can maintain chemical communication in the novel host system. Likewise, whether bark beetle attacks are synchronized to successfully colonize and kill jack pine trees could be important to determine the outbreak dynamics of the mountain pine beetle in the novel ecosystem. From a practical perspective, these results would be useful for the development of attractive baits (lures) to monitor and even control mountain pine beetle populations in the novel jack pine forests.**