Elucidating pheromone and host volatile components attractive to the spruce beetle, Dendroctonus rufipennis (Coleoptera: Curculionidae), in eastern Canada

Abstract

AbstractFrontalin, seudenol, and a spruce terpene blend are key components of a lure for monitoring spruce beetle, Dendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae: Scolytinae) in eastern Canada, catching the highest number of beetles in several field trials. The standard two-component commercial lure for this species, developed from populations in western North America and composed of 95%:5% (±)-α-pinene and frontalin, failed to elicit attraction to traps in Atlantic Canada; thus a series of trapping experiments were conducted to identify an improved combination of pheromone and host volatiles for this region. Analysis of volatiles from D. rufipennis collected from Newfoundland and Nova Scotia, Canada detected seudenol as an additional female-produced component. Laboratory analysis of the eastern host (Picea glauca (Moench) Voss; Pinaceae) detected the presence of 75%:25% (±)-α-pinene; however, a two-component lure comprised of 75%:25% (±)-α-pinene and frontalin caught no more beetles than an unbaited control. Frontalin and seudenol alone or spruce terpene blend and ethanol alone typically had among the lowest trap catches, but when combined they caught the highest numbers of D. rufipennis, supporting the hypothesis that host volatiles synergise attraction to pheromones. Our results highlight the importance of geographic variation in the response to pheromones and kairomones in this bark beetle.