title: Chemical similarity between historical and novel host plants promotes range and host expansion of the mountain pine beetle in a naïve host ecosystem.
abstract: Host plant secondary chemistry can have cascading impacts on host and range expansion of herbivorous insect populations. We investigated the role of host secondary compounds on pheromone production by the mountain pine beetle (Dendroctonus ponderosae) (MPB) and beetle attraction in response to a historical (lodgepole pine, Pinus contorta var. latifolia) and a novel (jack pine, Pinus banksiana) hosts, as pheromones regulate the host colonization process. Beetles emit the same pheromones from both hosts, but more trans-verbenol, the primary aggregation pheromone, was emitted by female beetles on the novel host. The phloem of the novel host contains more α-pinene, a secondary compound that is the precursor for trans-verbenol production in beetle, than the historical host. Beetle-induced emission of 3-carene, another secondary compound found in both hosts, was also higher from the novel host. Field tests showed that the addition of 3-carene to the pheromone mixture mimicking the aggregation pheromones produced from the two host species increased beetle capture. We conclude that chemical similarity between historical and novel hosts has facilitated host expansion of MPB in jack pine forests through the exploitation of common host secondary compounds for pheromone production and aggregation on the hosts. Furthermore, broods emerging from the novel host were larger in terms of body size.
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada.
authors.forename: Nadir
authors.initials: N
authors.lastname: Erbilgin
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada.
authors.forename: Cary
authors.initials: C
authors.lastname: Ma
authors.affiliation: Environment and Sustainable Resources Development, Forest Management Branch, Peace River, AB, T8S 1T4, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Whitehouse
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada.
authors.forename: Bin
authors.initials: B
authors.lastname: Shan
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Najar
authors.affiliation: Department of Biological Sciences, University of Alberta, 214A Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada.
authors.forename: Maya
authors.initials: M
authors.lastname: Evenden
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D017753:Ecosystem; D005426:Flight, Animal; D005843:Geography; D058507:Host Specificity / Q000502:physiology*; D039821:Monoterpenes / Q000032:analysis; D009656:North America; D010675:Pheromones / Q000032:analysis; D028223:Pinus / Q000737:chemistry* / Q000469:parasitology*
chemical_list: D039821:Monoterpenes; D010675:Pheromones
keywords: Dendroctonus ponderosae; Pinus banksiana; boreal forest; invasion biology; jack pine