TEMPORAL AND VERTICAL DISTRIBUTION OF BARK BEETLES (COLEOPTERA: SCOLYTIDAE) CAPTURED IN BARRIER TRAPS AT BAITED AND UNBAITED LODGEPOLE PINES THE YEAR FOLLOWING ATTACK BY THE MOUNTAIN PINE BEETLE

Abstract

AbstractBark beetles were trapped for two summers in a mature stand of lodgepole pine, Pinus contorta var. latifolia Engelmann (Pinaceae), infested by mountain pine beetle, Dendroctonus ponderosae Hopkins, near Princeton, British Columbia. Columns of flight-barrier traps were suspended next to uninfested live trees and from dead brood trees containing new adult beetles. The brood trees had been treated in the previous year with mountain pine beetle pheromone bait alone or in combination with Ips pini Say (Coleoptera: Scolytidae) pheromone bait and subsequently killed by mountain pine beetles. A total of 3376 individuals from 30 species of Scolytidae were captured in the traps. Most of the species for which lodgepole pine is a nonhost or occasional host were captured in low numbers (one or two specimens). The most abundant species (> 30 individuals) were D. ponderosae, I. pini, Hylurgops porosus LeConte, Pityogenes knechteli Swaine, and Trypodendron lineatum Olivier. The treatments affected captures of mountain pine beetles and I. pini but only in the year when trees were either unbaited or baited simultaneously for mountain pine beetle and I. pini. There were significant differences among the five most abundant species in the mean heights and mean Julian dates of capture. In addition to host condition requirements, these differences reflected partitioning of the food and habitat resource and competitive interactions among species. There was no interaction between treatment and trap height, indicating that treatment did not affect the height distribution of flying beetles.