Mountain pine beetle (<i>Dendroctonus ponderosae</i>) can produce its aggregation pheromone and complete brood development in naïve red pine (<i>Pinus resinosa</i>) under laboratory conditions

Abstract

Mountain pine beetle (Dendroctonus ponderosae Hopkins; Coleoptera: Curculionidae, Scolytinae) has killed millions of hectares of lodgepole pine (Pinus contorta Douglas ex Loudon) forest in western Canada, where it has recently established in the novel host jack pine (Pinus banksiana Lamb.) and threatens naïve red pine (Pinus resinosa Aiton) forests as the current outbreak expands eastward. It is therefore crucial to understand whether red pine is a suitable host for D. ponderosae. Host suitability was assessed by comparing the ability of beetles to produce pheromones and complete their development in red pine bolts inoculated with mating beetle pairs. We detected two of four primary pheromones, including trans-verbenol and verbenone, but not exo-brevicomin or frontalin. Beetle brood successfully developed in bolts, with reproductive parameters (e.g., female and larval galleries, pupal chamber, and number of broods emerged per mated pair of adults) that were similar to those reported from the beetle’s historical host lodgepole pine and the novel host jack pine. These results provide initial evidence that red pine is a suitable host for D. ponderosae. However, it is unclear how either low concentrations or an absence of exo-brevicomin, frontalin, and the synergistic monoterpene myrcene could affect host colonization and establishment of beetles.