Canadian Forest Service Publications

Survival of the Douglas-Fir Beetle in Peeled and UnPeeled Logs and in Stumps. 2005. Shore, T.L.; Riel, W.G.; Safranyik, L.; Castonguay, J. Forest Science 20(3): 149-153.

Year: 2005

Issued by: Pacific Forestry Centre

Catalog ID: 25516

Language: English

Availability: Order paper copy (free)

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Abstract

The Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) can cause significant morality to mature Douglas-fir trees (Pseudotsuga meniesii (Mirb.) Franco) during epidemics. Treatment methods are required to reduce local beetle populations to less-damaging levels. We conducted a study to compare the effect on beetle survival of peeling bark from infested logs at two times of years. By Aug., all beetles in bark from logs peeled in July were dead compared with 155.2 beetles/m2 of bark in unpeeled logs. In bark from logs peeled at the end of Aug. and left over winter, there were 3.4 beetles/m2 of bark surface compared with 62.3/m2 in unpeeled logs. It was concluded that peeling logs reduces beetle populations, particularly if done early in the summer. We also examined beetle survival in stumps over winter and found that a mean 70.4 beetles/stump, or 125.6/m2 of stump surface survived winter. It is estimated that it would take beetles emerging from 24 stumps to kill a tree.