Gallery success, brood production, and condition of mountain pine beetles (Coleoptera: Curculionidae) reared in whitebark and lodgepole pine from Alberta, Canada

Abstract

Breeding pairs of mountain pine beetle (Dendroctonus ponderosae Hopkins) were introduced into freshly cut bolts of whitebark pine (Pinus albicaulis Engelm.) and lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson) in the laboratory. Brood adults emerging from the bolts were collected and galleries were dissected to compare reproductive success, brood production, and adult condition between the two pines. Beetles were more likely to establish egg galleries that produced brood in lodgepole pine than in whitebark pine. Larval gallery density per centimetre of egg gallery was significantly higher in whitebark pine than in lodgepole pine; however, egg galleries also tended to be shorter in whitebark pine bolts, and consequently, brood adults emerging production per gallery did not differ between the two host species. Female body size, mass, and fat content of brood adults and survival from larva to adult did not differ between beetles reared in the two hosts. Though this no-choice assay did not simulate the sequence of events occurring during host selection, these results are consistent with other data suggesting that beetles could be less likely to attack whitebark pines in southwestern Alberta. Whitebark pines that are attacked will produce brood in similar numbers and condition as those from lodgepole pines.