Containment and concentration of infestations of the western balsam bark beetle, Dryocoetes confusus (Coleoptera: Scolytidae), using the aggregation pheromone exo-brevicomin
| Autor: | John H. Borden, T.L. Pratt, Arthur J. Stock |
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| Rok vydání: | 1994 |
| Předmět: | |
| Zdroj: | Canadian Journal of Forest Research. 24:483-492 |
| ISSN: | 1208-6037 0045-5067 |
| DOI: | 10.1139/x94-065 |
| Popis: | Containment and concentration of infestations of the western balsam bark beetle, Dryocoetes confusus Swaine, was demonstrated when (±)-exo-brevicomin released at 0.4 mg/24 h was applied to single subalpine firs, Abieslasiocarpa (Hook.) Nutt., on a 50-m grid over 9-ha blocks, or released at 0.8 mg (24 h/tree)−1 applied to two trees at 50-m centres over the central 4 ha of 16-ha blocks. Nearest-neighbour distance between red trees and newly mass-attacked trees was 24 m in the central 4 ha of baited 16-ha blocks, compared with 13.8 m in control blocks, suggesting a movement of beetles away from "normal" attack centres. Treatments with exo-brevicomin at two trees per spot concentrated 89% of newly mass-attacked trees within 10 m of baited trees, clearly indicating the potential for semiochemical-based management of D. confusus. Within-stand distribution of attacked trees was highly aggregated (Clark–Evans test), in both treated and control blocks. The highly aggregated pattern of attack in control blocks could have been a product of stand structure, and it is hypothesized that D. confusus plays a role in the regeneration of its host by initiating small gaps that favour subalpine fir reproduction. If so, there is potential for using semiochemicals to manipulate D. confusus populations within a patch or selection logging system to maintain cover in climax subalpine forests. |
| Databáze: | OpenAIRE |
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