Effects of host quality parameters on fitness of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae).

The mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), is a destructive forest pest endemic to western North America. It breeds in the phloem of Pinus species, and during epidemic population levels, healthy trees are killed. The objective of this study was to determine how the quality of brood trees affects the fitness of mountain pine beetle offspring. The lipid content of offspring was measured relative to brood tree quality. Maternal effects were tested by rearing beetles of different sizes in hosts of constant quality and measuring brood characteristics. The population characteristics of beetles responding to aggregation pheromones were compared to that of beetles emerging from infested trees. The largest offspring were found to emerge first, but did not have the highest lipid contents. Large and small beetles were found to have similar absolute fat contents. Females were not affected by their mother's condition, but males were marginally affected.