Area‐wide application of verbenone‐releasing flakes reduces mortality of whitebark pine Pinus albicaulis caused by the mountain pine beetle Dendroctonus ponderosae |
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Authors: | Nancy E. Gillette E. Matthew Hansen Constance J. Mehmel Sylvia R. Mori Jeffrey N. Webster Nadir Erbilgin David L. Wood |
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Affiliation: | 1. USDA Forest Service, PSW Research Station, Albany, CA 94710, U.S.A.;2. USDA Forest Service, Rocky Mountain Research Station, Logan, UT 84321, U.S.A.;3. USDA Forest Service, Forest Health Protection, Wenatchee, WA 98801, U.S.A.;4. Webster Forestry Consulting, Redding, CA 96002, U.S.A.;5. Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2E3, Canada;6. Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, U.S.A. |
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Abstract: | - 1 DISRUPT Micro‐Flake Verbenone Bark Beetle Anti‐Aggregant flakes (Hercon Environmental, Inc., Emigsville, Pennsylvania) were applied in two large‐scale tests to assess their efficacy for protecting whitebark pine Pinus albicaulis Engelm. from attack by mountain pine beetle Dendroctonus ponderosae Hopkins (Coleoptera: Scolytinae) (MPB). At two locations, five plots of equivalent size and stand structure served as untreated controls. All plots had early‐ to mid‐outbreak beetle populations (i.e. 7.1–29.2 attacked trees/ha). Verbenone was applied at 370 g/ha in both studies. Intercept traps baited with MPB aggregation pheromone were placed near the corners of each plot after the treatment in order to monitor beetle flight within the plots. Trap catches were collected at 7‐ to 14‐day intervals, and assessments were made at the end of the season of stand structure, stand composition and MPB attack rate for the current and previous years.
- 2 Applications of verbenone flakes significantly reduced the numbers of beetles trapped in treated plots compared with controls at both sites by approximately 50% at the first collection date.
- 3 The applications also significantly reduced the proportion of trees attacked in both Wyoming and Washington using the proportion of trees attacked the previous year as a covariate in the model for analysis of current year attack rates; in both sites, the reduction was ≥ 50%.
- 4 The flake formulation of verbenone appears to have promise for area‐wide treatment by aerial application when aiming to control the mountain pine beetle in whitebark pine forests.
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Keywords: | Aerial application anti‐aggregation pheromones bark beetles behavioural chemicals Coleoptera pheromones Scolytinae semiochemicals |
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