Canadian Forest Service Publications

Coarse-scale hazard rating of western hemlock looper in British Columbia. 2001. Borecky, N.; Otvos, I.S. Pages 6-15 in A.M. Liebhold, M.L. McManus, I.S. Otvos, and S.L.C. Fosbroke, editors. Proceedings - Integrated management and dynamics of forest defoliating insects, August 15-19, 1999, Victoria BC, Canada. USDA Forest Service, Northeastern Research Station, Newtown Square, PA, General Technical Report NE-277.

Year: 2001

Available from: Pacific Forestry Centre

Catalog ID: 18308

Language: English

Series: USDA General Technical Report

CFS Availability: Not available through the CFS (click for more information).

Abstract

The western hemlock looper (Lambdina fiscellaria lugubrosa (Hulst.)) is a serious defoliating pest in western North America. during the 1990-1995 outbreak, this pest was responsible for approximately 63 000 ha of stand mortality in British Columbia. There have been 14 distinct outbreaks, increasing in duration and severity over the past 87 years. Outbreaks tend to occur in Coastal and Interior Western Hemlock biogeoclimatic zones and generally last 2 to 5 years. A Western Hemlock Looper Hazard Rating System (WHLHRS) is being developed to aid forest managers in dealing with western hemlock looper outbreaks. Province-wide hazard rating has been accomplished at a 2-kilometre grid scale. The hazard-rating values for this grid are based upon the locations of past outbreaks, presence of host forest stands, biogeoclimatic zones, climatic variables, and elevation. This hazard rating mapping will be useful for future pheromone trap placement, in addition to aiding forest managers in identifying susceptible forests. The forecasting of defoliation events and the identification of larger scale risk areas are the goals of the WHLHRS. The WHLHRS, as a whole, is anticipated to aid forest managers in dealing with outbreaks of western hemlock looper in an effective fashion through either direct control measures or modified silviculture practices.

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