As the mountain pine beetle (MPB) has spread from British Columbia into Alberta, there is a possibility that it will invade the jack pine forests (JP) of western Canada. The probability of this invasion has increased because global climate changes are expected to promote warmer winter temperatures in northerly latitudes and at higher elevations. I use this spreading outbreak as a model system in my program to explore questions of broad relevance to invasion biology. A major difference between the historical range of MPB in cordilleran LP forests and the boreal JP forest is the presence of a serious defoliator, jack pine budworm (JPB) and the absence of outbreak species of bark beetles in the JP forest. In the endemic population phase, MPB generally infests trees that have been partially attacked by other insects; thus, interaction with these insects is an important determinant of MPB persistence at low population levels. We might expect similar interactions between MPB and JPB in the JP forest, as continuous defoliation of JP trees by JPB usually does not result in immediate tree mortality and may support opportunities for MPB attack. However it is hard to predict if and how JPB defoliation will affect JP tree susceptibility to MPB and its symbiotic fungi. The outcome of my most recent research will be presented and discussed.
doi: 10.1603/ICE.2016.47513