The bionomics of the mountain pine beetle in lodgepole pine forests: Establishing a context

Due to the significant impacts of mountain pine beetle (Dendroctonus ponderosae Hopk.) epidemics on the pine forests of western North America, there exists an extensive body of literature devoted to its bionomics. This paper reviews the critical aspects of mountain pine beetle biology and ecology that enable its eruptive population fluctuations in lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forests: dispersal and colonization; insect-host interactions; cold tolerance; and synchrony and phenology. The potential for mountain pine beetle populations to establish, persist and ultimately increase to outbreak levels is a function of the beetle's capacity to locate, colonize and reproduce within highly resistant host trees situated in thermal environments conducive to overwintering survival and with sufficient heat accumulation to maintain a synchronous univoltine life cycle. Management strategies and tactics intended to mitigate the impact of outbreaks must be based on an understanding of the effects these constraints have on populations and the subsequent adaptations that the mountain pine beetle has evolved to overcome them.