The current mountain pine beetle (MPB) epidemic in British Columbia is the largest bark beetle outbreak in recorded history. Despite the epidemic dimensions of the current MPB outbreak, very little is known about the molecular mechanisms and the population genomics of the interacting bark beetles, fungi, and trees. The proposed project will deliver advanced knowledge of the interacting biological systems and the population dynamics of the MPB epidemic. This information will be used for improved ecological risk modelling in support of improved forest management practices and in support of strategies for controlling or coping with such massive epidemics. The project will benefit Canadian society through the economic, environmental, and social benefits that result from effective long-term protection of Canada’s forest resources from insect pests and insect-associated fungal pathogens.