Massive outbreak of mountain pine beetle in Canadian pine forests

This paper presents a summary on mountain pine beetle (Dendroctonus ponderosae Hopkins (Coleoptera: Scolytinae)) biology and current outbreak in lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forests of western Canada. The outbreak is unprecedented in scale and has a large ecological and economic impact. A trend towards warmer, drier summers and fewer cold spells in the winter in combination with the abundance of mature pine (due to an effective wildfire suppression program) are the main causes of the outbreak. Spreading at a high rate, by 2005 the epidemic affected 8.7 million hectares of pine forests in British Columbia (BC). The Chilcotin plateau the in southern interior of BC is heavily infested, and even young stands are killed although they are unsuitable for beetle reproduction. In 2006, a mass dispersal of beetles caused widespread attacks into new habitats in eastern BC and Alberta. There is a potential risk of expansion of the beetle into jack pine (Pinus banksiana Lamb.) forests in Alberta and Saskatchewan.