The mountain pine beetle (Dendroctonus ponderosae Hopkins) is a bark beetle that is native to pine forests of western North America and the Black Hills of South Dakota. Recent eastward range expansion into stands of jack pine (Pinus banksiana) and associated hybrids with lodgepole pine (Pinus contorta) in western Canada has created concern that the insect will continue moving eastward. In the Great Lakes region, mountain pine beetle would encounter novel species of pines and associated insect fauna; interactions with which are largely unexplored. We baited logs of jack pine with lures for mountain pine beetle and Ips grandicollis (Eichhoff) alone and in combination in a 2 × 2 factorial design in the Black Hills of South Dakota. Both insects occur in this region, but not jack pine, a common species in the Great Lakes region of North America at risk of invasion by mountain pine beetle. We measured attraction and reproduction of insects that colonized the logs. Ips grandicollis were significantly more attracted to logs of jack pine baited with their aggregation pheromone, ipsenol, than unbaited logs or those baited with pheromones of mountain pine beetle and myrcene, a host volatile. Colonization by I. grandicollis was inhibited by the presence of lures for mountain pine beetle. We also found larvae of longhorn borers, likely ­ Monochamus spp., infesting logs. These borers, which act as competitors and facultative predators of bark beetles, were significantly attracted to logs baited with ipsenol over those baited with lures for mountain pine beetle. Our results suggest that if mountain pine beetle were to invade the Great Lakes Region, common bark and wood-boring species such as I. grandicollis and longhorn borers would not compete with mountain pine beetles at tree-colonizing stages, and thus could pose little resistance to invasion.

山松甲虫 ( Dendroctonusponderosae Hopkins) 是一种树皮甲虫，原产于北美西部的松树林和南达科他州的黑山。最近向东扩展到加拿大西部的针叶松（Pinus banksiana）和与黑松（Pinus contorta）相关的杂交种，引起了人们对这种昆虫将继续向东移动的担忧。在五大湖地区，山松甲虫会遇到新的松树种和相关的昆虫动物群；与它们之间的相互作用在很大程度上是未开发的。我们用山松甲虫和Ips grandicollis (Eichhoff) 单独和组合在南达科他州黑山的 2 × 2 因子设计中。这两种昆虫都出现在该地区，但不包括北美五大湖地区常见的有山松甲虫入侵风险的杰克松。我们测量了在原木上定居的昆虫的吸引力和繁殖。与未诱饵的原木或以山松甲虫和月桂烯（一种宿主挥发性物质）的信息素为诱饵的原木相比，Ips grandicollis更容易被以聚集信息素 ipsenol 为诱饵的杰克松原木所吸引。山松甲虫诱饵的存在抑制了 I. grandicollis 的定殖。我们还发现了长角螟的幼虫，可能是Monochamusspp.，感染日志。这些螟是树皮甲虫的竞争者和兼性捕食者，与用山松甲虫诱饵诱饵的原木相比，这些蛀虫更容易被用 ipsenol 诱饵的原木所吸引。我们的研究结果表明，如果山松甲虫入侵五大湖地区，常见的树皮和蛀木物种，如I. grandicollis和长角螟在树木定殖阶段不会与山松甲虫竞争，因此几乎不会产生抵抗力到入侵。