Response of the clerid predatorThanasimus dubius (F.) to bark beetle pheromones and tree volatiles in a wind tunnel

Tree volatiles and pheromones produced by southern bark beetles were bioassayed for response by the clerid predatorThanasimus dubius (F.). Upwind flights in a laboratory olfactometer, modified from Visser (1976), were used to determine the attractiveness of compounds. Differences in response to a solvent control and pheromone treatment were tested for statistical significance using the Wilcoxon signed ranks test. Both sexes ofT. dubius responded to frontalin, ipsdienol, and -pinene in a dose-dependent manner with different but overlapping concentration ranges. Strong differences between the sexes were observed in response totrans-verbenol, verbenone, andl--pinene. Neither sex responded to ipsenol orendo-brevicomin.Miss. Agric. and For. Exp. Sta. Publication No. 5251.