Terpene composition of lodgepole and jack pine and its relationship to the success of the mountain pine beetle.

Climate change and range expansion of an aggressive bark beetle: evidence of higher beetle reproduction in naïve host tree populations

“…Defence is costly, however, and in populations where selection pressures are low, it is likely that plants would minimize the allocation of resources to defence, which would come at the expense of growth (Herms & Mattson 1992). Clark (2008) showed that lodgepole pine from regions not previously exposed to mountain pine beetle differed significantly in terms of their defensive monoterpenes when compared to those in areas exposed to periodic beetle outbreaks, lending support to our findings. Similarly, populations of ponderosa pine that have suffered from heavy bark beetle‐caused mortality have a greater frequency of trees containing higher concentrations of the toxic monoterpene limonene (Sturgeon 1979).…”

“…(Hemingway, McGraw & Barras 1977), that reduce the digestibility of the available nutrients. This was not tested in this study, but Clark (2008) found a weaker secondary resinosis response by trees from outside the mountain pine beetle’s historic range than in trees from within its normal distribution.…”

“…Where eruptive populations have not been present, or at least not frequent, it is conceivable that defence capabilities at the population level would be relatively low (Herms & Mattson 1992), resulting in ‘defence‐free space’ (Ghandi & Herms 2010; Raupp, Shrewsbury & Herms 2010). Specifically, lodgepole pine was shown to differ with respect to their defensive monoterpenes in areas with and without historic mountain pine beetle presence (Clark 2008); however, the effects on insect reproduction have never been studied.…”

Potential for range expansion of mountain pine beetle into the boreal forest of North America

“…Furniss and Schenk (1969) reported mountain pine beetles attacking jack pine planted in Idaho, well outside the beetle's native range; Cerezke (1995) demonstrated that the beetles can naturally attack cut bolts of jack pine placed in infested lodgepole pine stands. Levels of a-pinene tend to be high in both the constitutive and induced resins of jack pine (Raffa and Smalley 1995;Wallin and Raffa 1999), and Clark (2008) showed that a-pinene concentrations induced by simulated mountain pine beetle attacks are several times greater in jack pine than in lodgepole pine. Thus, once pioneer beetles have initiated attacks on jack pine, high levels of apinene may facilitate production of aggregation pheromones and increase the probability of successful mass attack.…”