Metabolic Budget Analysis of Mountain Pine Beetle Following Dispersal in Western Montana

Mountain pine beetle is an irruptive forest insect and disturbance agent in pine forests of western North America, infesting almost all western pine species. Past outbreaks have killed tens of millions of acres of mature pines across the western United States. In spite of abundant work on the insect’s ecology and tree killing capability, little is known about dispersal dynamics that are important to understand given potential threats of range expansion to pine forests of eastern North America. We identified areas in western Montana with active mountain pine beetle populations and investigated how many fewer beetles would be captured at distances farther away from active infestations. In the summer of 2020, we placed twenty baited Lindgren funnel traps along a 180-mile transect through western Montana from areas with established populations of mountain pine beetle to areas with no visible active infestations. Weekly collections were made during the peak of mountain pine beetle activity, from 4 August to 26 August. High numbers were captured at sites with no apparent proximate active infestations. While source populations cannot be confirmed, capture patterns away from pine forests provide can some insight into dispersal pressure given aerial survey data. Analysis of metabolic budgets of individual insects continues, but is not included in today’s presentation.