Temperature-driven range expansion of an irruptive insect heightened by weakly coevolved plant defenses.

ABSTRACT: Warming climate has increased access of native bark beetles to high-elevation pines that historically received only intermittent exposure to these tree-killing herbivores. Here we show that a dominant, relatively naïve, high-elevation species, whitebark pine, has inferior defenses against mountain pine beetle compared with its historical lower-elevation host, lodgepole pine. Lodgepole pines respond by exuding more resin and accumulating higher concentrations of toxic monoterpenes than whitebark pine, where they co-occur. Furthermore, the chemical composition of whitebark pine appears less able to inhibit the pheromonal communication beetles use to jointly overcome tree defenses. Despite whitebark pine's inferior defenses, beetles were more likely to attack their historical host in mixed st

SUBMITTER: Raffa KF 

PROVIDER: S-EPMC3568305 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature