The response of Dendroctonus valens (Coleoptera: Scolytidae) and Temnochila chlorodia (Coleoptera: Trogossitidae) to Ips paraconfusus (Coleoptera: Scolytidae) pheromone components and verbenone
The red turpentine beetle, Dendroctonus valens LeConte, 1860 (Coleoptera: Curculionidae, Scolytinae), is a common bark beetle species found throughout much of North America and China. In 2004, we observed that California fivespined ips, Ips paraconfusus Lanier, 1970 (Coleoptera: Curculionidae, Scolytinae), attack densities in logging debris were inversely related to D. valens attacks on freshly-cut stumps, which led to the demonstration that components of the aggregation pheromone of I. paraconfusus inhibited the response of D. valens to attractant-baited traps (Fettig et al. 2005). In this study, we test the response of D. valens and Temnochila chlorodia (Mannerheim, 1843) (Coleoptera: Trogositidae), a common bark beetle predator, to racemic ipsenol, racemic ipsdienol, and (-)-cis-verbenol (IPSR) in the presence and absence of two release rates of (-)-verbenone. The addition of a relatively low release rate of (-)-verbenone (4 mg / 24 h) to attractant-baited traps did not affect catch, and had no significant effect on the response of D. valens to IPSR. IPSR significantly reduced D. valens attraction to baited traps. The addition of high release rates of (-)-verbenone (50 mg / 24 h) to IPSR significantly increased inhibition to levels above that observed for IPSR; however, the effect was not significantly different from (-)-verbenone (50 mg / 24 h). Temnochila chlorodia was attracted to traps baited with (-)-alpha-pinene, (+)-3-carene and (+)-alpha-pinene. The addition of (-)-verbenone (50 mg / 24 h) significantly increased attraction. Traps baited with IPSR caught significantly more T. chlorodia than those baited with (-)-verbenone. Few other beetles were collected. We are hopeful that these results will help facilitate the development of an effective tool for protecting Pinus spp. from D. valens infestations.
Fettig, C.J.; McKelvey, S.R.; Dabney, C.P.; Borys, R.R. 2007. The response of Dendroctonus valens (Coleoptera: Scolytidae) and Temnochila chlorodia (Coleoptera: Trogossitidae) to Ips paraconfusus (Coleoptera: Scolytidae) pheromone components and verbenone. The Canadian Entomologist. 139: 141-145.