Comparison of Naturally and Synthetically Baited Spruce Beetle Trapping Systems in the Central Rocky Mountains

Abstract

We compared naturally baited trapping systems to synthetically baited funnel traps and fallen trap trees for suppressing preoutbreak spruce beetle, Dendroctonus rufipennis Kirby, populations. Lures for the traps were fresh spruce (Picea spp.) bolts or bark sections, augmented by adding female spruce beetles to create secondary attraction. In 2003, we compared a naturally baited system ("bolt trap") with fallen trap trees and with synthetically baited funnel traps. Trap performance was evaluated by comparing total beetle captures and spillover of attacks into nearby host trees. Overall, the trap systems did not significantly differ in spruce beetle captures, although bolt traps caught 6 to 7 times more beetles than funnel traps during the first 4 wk of testing. Funnel traps with synthetic lures had significantly more spillover than either trap trees or bolt traps. The study was repeated in 2004 with modifications including an enhanced blend synthetic lure. Again, trap captures were generally similar among naturally and synthetically baited traps, but naturally baited traps had significantly less spillover. Although relatively labor-intensive, the bolt trap could be used to suppress preoutbreak beetle populations, especially when spillover is undesirable. Our work provides additional avenues for management of spruce beetles and suggests that currently used synthetic lures can be improved.

Spruce Beetle Biology, Ecology and Management in the Rocky Mountains: An Addendum to Spruce Beetle in the Rockies

“…Studies completed by Knight [156] determined the mean number of attacking beetles required to kill a standing tree with a specific breast height diameter. Hansen et al [157] developed a method using baited funnel traps to estimate tree mortality and associated population phase of spruce beetle. Model predictions associated with trap results suggest that funnel trap captures can be reliably used to estimate relative levels of tree mortality, expressed as population phase.…”

“…Hansen et al [157] compared naturally baited trapping systems to synthetically baited funnel and fallen trap trees for suppressing pre-outbreak spruce beetle populations. Lures for the traps were fresh Engelmann spruce bolts or bark sections augmented by adding female spruce beetles to create secondary attraction.…”

“…Lures for the traps were fresh Engelmann spruce bolts or bark sections augmented by adding female spruce beetles to create secondary attraction. Previously, Hansen et al [157] compared a naturally baited system (-bolt trap‖) with fallen trap trees and with synthetically baited funnel traps. Trap performance was evaluated by comparing total beetle captures and spillover of attacks into nearby host trees.…”

“…Funnel traps with synthetic lures had significantly more spillover than either trap trees or bolt traps. They repeated the study with modifications that included an enhanced blend synthetic lure [157]. Trap captures were generally similar among naturally and synthetically baited traps, but naturally baited traps had significantly less spillover.…”

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

“…In western North America, specifically Alaska, northwestern Alberta, southeastern British Columbia, Colorado, Wyoming, and Utah, a three-component lure of a-pinene, frontalin, and MCOL was typically reported as most attractive to D. rufipennis (Borden et al 1996;Ross et al 2005;Hansen et al 2006), although with some inconsistencies in attraction to (1)-, (2)-, and (7)-MCOL among locations (Borden et al 1996). These studies used three ratios of a-pinene: 89%:11% (7), racemic, and 95%:5% (7), respectively.…”