Disruption of red turpentine beetle attraction to baited traps by the addition of California fivespined ips pheromone components

Abstract

AbstractThe red turpentine beetle,Dendroctonus valensLeConte (Coleoptera: Scolytidae), is a common bark beetle species found throughout much of North America. In California,D.valensand the California fivespined ips,Ips paraconfususLanier (Coleoptera: Scolytidae), are sympatric and often colonize the same tree. In an unrelated study, we observed thatI.paraconfususattack densities in logging debris were inversely related toD.valensattacks on freshly cut stumps. In this study, we test the hypothesis that allomonal inhibition occurs between these two species. Components of the aggregation pheromone ofI.paraconfusus(racemic ipsenol, (+)-ipsdienol, and (–)-cis-verbenol) inhibited the response ofD.valensto attractant-baited traps. Substitution of racemic ipsdienol for (+)-ipsdienol did not alter this effect. Doubling the release rate did not enhance inhibition. Racemic ipsdienol was not attractive toI.paraconfusus.Temnochila chlorodia(Mannerheim, 1843) (Coleoptera: Trogositidae), a common bark beetle predator, was attracted to theI.paraconfususaggregation pheromone. These results could have important implications for the development of an effective semiochemical-based management tool forD.valens.