The ecological interaction of the mountain pine beetle and jack pine budworm in the boreal forest

Abstract

As climate change facilitates the range and host expansion of insect species into new ecosystems, the development of newstrategies for managing and preventing biological invasion is receiving considerable interest. In recent years, the range ofthe mountain pine beetle (Dendroctonus ponderosae Hopkins) has expanded from lodgepole pine-dominated forests eastof the Rocky Mountains into lodgepole x jack pine hybrid forest of western Alberta, and may soon invade jack pine forestsof the boreal. Our understanding of factors contributing colonization of jack pine by mountain pine beetle is far fromcomplete and several factors may limit its spread in these forests, including tree resistance and competitors. Among these,the jack pine budworm (Choristoneura pinus pinus Freeman) is one of the most important insect enemies of jack pine andan outbreak defoliator that potentially weakens jack pine trees, which may make them more susceptible to MPB attacks.To develop effective management strategies in the face of the short-run impacts of climate change, we need an in-depthunderstanding of factors influencing establishment and survival of the beetle in jack pine forests.Key words: Choristoneura pinus pinus, Dendroctonus ponderosae, jack pine, range expansion, invasion biology, climatechange in the boreal forest, conifer-mediated interactions, tree induced defences, tripartite interactions