Antennal olfactory responses of black turpentine beetle, Dendroctonus terebrans (Olivier), to bark beetle pheromones and host terpenes

Electroantennograms (EAGs) were recorded from male and female black turpentine beetles, Dendroctonus terebrans (Olivier), exposed to bark beetle pheromones and host terpenes. The dose-response curves indicated similarities in the receptor mechanisms for both sexes for each compound. Antennal sensitivity was greatest to endo-brevicomin, which correlates with the importance of the compound in the behavior of the beetles. At above-threshold concentrations, EAGs were greatest to endo-brevicomin and frontalin, suggesting a large population of antennal receptors for these compounds. A large population of receptors would be expected for compounds that play such a significant role in this beetle's behavior. Beetles were also shown to have receptors that respond to the Is pheromones, ipsenol, and ipsdienol