Field Response of Dendroctonus valens (Coleoptera: Scolytidae) and a Major Predator, Temnochila chlorodia (Coleoptera: Trogositidae), to Host Kairomones and a Dendroctonus spp. Pheromone Component1

Abstract

The red turpentine beetle, Dendroctonus valens (LeConte) (Coleoptera: Scolytidae), is a common bark beetle species found throughout much of North America. Aggregation pheromones have yet to be isolated and identified for D. valens. In this study, we examined the response of D. valens and a bark beetle predator, Temnochila chlorodia (Mannerheim) (Coleoptera: Trogositidae), to host produced kairomones and to the Dendroctonus spp. pheromone component exo-brevicomin. A total of 11,604 D. valens and 586 T. chlorodia were captured in multiple-funnel traps over a 14-wk period from 27 March to 5 July 2002. There was no significant difference in trap catch related to gender. The ratio of males to females was 1.01 for D. valens and 0.97 for T. chlorodia. Dendroctonus valens showed significant attraction to (+)-α-pinene, (−)-β-pinene, and (+)-3-carene, but the addition of ethanol did not significantly increase trap catch. Racemic exo-brevicomin was not attractive to D. valens and significantly reduced its attraction to the monoterpene and ethanol blend. This observation, in combination with results from other authors, suggests that D. valens is not responding to the western pine beetle, D. brevicomis LeConte, pheromone or any of the individual components. Potential explanations for why D. valens is attracted to D. brevicomis infested trees are provided. There were no significant differences in the trap catch of T. chlorodia among unbaited traps or traps baited with (+)-α-pinene, (−)-β-pinene, and (+)-3-carene or (+)-α-pinene, (−)-(β-pinene, and (+)-3-carene, and ethanol. The addition of exo-brevicomin significantly increased attraction. During the course of this study, a single peak in flight activity was observed during late May through early June for both species.

The effects of mechanical fuel reduction treatments on the activity of bark beetles (Coleoptera: Scolytidae) infesting ponderosa pine

“…In general, flight periodicity agreed with descriptions provided by other authors for similar locations (Fettig et al, 2004(Fettig et al, , 2005Gaylord et al, 2006). There was a consistent trend among sites and species with more individuals collected in latespring/early-summer than in late-summer/fall (Fig.…”

“…Hobson et al (1993) also reported significant increases in D. valens trap catch attributable to 3-carene and (+)-a-pinene. Combinations of these three monoterpenes are a highly effective bait in multiple-funnel traps (Fettig et al, 2004). In our study, initial quantities of a-pinene, b-pinene, 3-carene and myrcene eluting from chips were 16.9, 27.9, 23.7 and 23.9 times greater, respectively, than lopped-and-piled slash (Fig.…”

“…Overall, significantly more D. valens were collected in attractant-baited traps than chip-baited traps (19.6 AE 5.3 versus 12.6 AE 8.1; P = 0.004), perhaps because the chips desiccated rapidly and were attractive for a shorter period of time. For example, no significant difference was observed between trap catches when analyses were limited to the initial four sampling periods in May and June (21.3 AE 5.3 versus 32.7 AE 13.1; P = 0.14), which corresponds with peak flight activity for D. valens in California (Fettig et al, 2004). Few D. valens were collected in traps baited for Ips species.…”

Pine monoterpenes and pine bark beetles: a marriage of convenience for defense and chemical communication

“…Responses by antennae to (R)-(+)-and (S)-())-a-pinene suggest different receptors for each enantiomer . (+)-a-Pinene, ())-b-pinene, and 3-carene are attractive in flight assays of North American populations Fettig et al 2004), but 3-carene is the best attractant in introduced populations in China (Sun et al 2004).…”

Delayed conifer mortality after fuel reduction treatments: interactive effects of fuel, fire intensity, and bark beetles

“…They also attack trees that are under attack by other bark beetles, such as western pine beetle (Fettig et al 2004). Attacks typically do not lead to tree mortality.…”