To develop safe and effective methods to protect whitebark pines, Pinus albicaulis Engelmann, and limber pines, Pinus flexilis James, from attack by mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), we compared verbenone and verbenone plus green leaf volatiles (GLVs) for prevention of beetle attack. We used two strategies: area-wide protection where semiochemical-releasing flakes are dispersed over the forest floor, and individual tree tests where flakes are applied to tree trunks. The area-wide bioassays were conducted by applying verbenone- and GLV-releasing flakes without stickers to the forest floor on 0.81-ha plots dominated by whitebark pines in the State of Washington with four replicates. We conducted individual tree bioassays by applying the same formulations with stickers to whitebark and limber pines in Montana and Colorado, respectively. In all three situations, both verbenone-alone and verbenone plus GLVs significantly increased the proportion of trees escaping mass attack by beetles, but the two formulations were not significantly different from one another. Despite a lack of significance at a Bonferroni-adjusted α = 0.05, adding GLVs gave slightly greater absolute levels of tree protection in most cases. Monitoring traps placed in the area-wide treatments in Washington showed similar outcomes for numbers of beetles trapped: both treatments had significantly fewer beetles than controls, and they were not significantly different from one another. At peak flight, however, plots with GLVs combined with verbenone had roughly 40% fewer beetles than plots with verbenone alone. GLVs are considerably cheaper than verbenone, so tests of higher application rates may be warranted to achieve enhanced tree protection at reasonable cost.
How to translate text using browser tools
1 August 2014
Efficacy of Verbenone and Green Leaf Volatiles for Protecting Whitebark and Limber Pines From Attack by Mountain Pine Beetle (Coleoptera: Curculionidae: Scolytinae)
Nancy E. Gillette,
Sandra J. Kegley,
Sheryl L. Costello,
Sylvia R. Mori,
Jeffrey N. Webster,
Constance J. Mehmel,
David L. Wood
ACCESS THE FULL ARTICLE
It is not available for individual sale.
This article is only available to subscribers.
It is not available for individual sale.
It is not available for individual sale.
Environmental Entomology
Vol. 43 • No. 4
August 2014
Vol. 43 • No. 4
August 2014
green leaf volatile (GLV)
pheromone flake
Pinus albicaulis
Pinus flexilis
semio-chemical