Seasonal variation of degree-day accumulation in relation to phenology of western spruce budworm, Douglas-fir tussock moth, and host trees in northeastern Oregon.

Abstract

The annual variation of degree-days and early summer phenology of Douglas-fir tussock moth, western spruce budworm, and their host trees was monitored over five to six seasons at two locations in the Blue Mountains. Accumulated degree-days and the phenology of bud burst and larval development were consistent and comparable at the two sites. Either degree-days or shoot elongation can be used to time simultaneous larval sampling of these two insects.

Citation

Wickman, Boyd E. 1988. Seasonal variation of degree-day accumulation in relation to phenology of western spruce budworm, Douglas-fir tussock moth, and host trees in northeastern Oregon. Res. Note. PNW-RN-482. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 12 p