Comparisons of mountain pine beetle (Dendroctonus ponderosaeHopkins) reproduction within a novel and traditional host: effects of insect natal history, colonized host species and competitors

摘要: During host-breadth expansion, phytophagous insects incur risk from potentially deleterious novel host environments at the same time as securing a potential escape in space or competing species. Bark beetles reproduce under bark of stems and branches mature, stressed moribund trees, may suffer high mortality plant defences inter- intraspecific competition. An epidemic mountain pine beetle (Dendroctonus ponderosae Hopkins) western Canada has extended to over 18.1 million hectares lodgepole (Pinus contorta Douglas ex. Loudon) forests. In some areas, have been found within interior hybrid spruces [Picea glauca (Moench) Voss × engelmannii Parry Engelmann], normally rare occurrence. Using reared naturally-infested spruce hosts, we examined effect female natal species colonized on ability attract mates logs deployed choice assay field setting. Additionally, whether arrival reproduction competitors such engravers (Ips spp.) was associated with reduced brood production. Females exhibited similar reproductive potentials. Recruitment establishment ovipositional galleries, larval galleries pupal chambers were typical hosts. Reproduction by spruce, although successful, significantly lower than pine. This reduction occurred despite being almost entirely free secondary beetles.