Canadian Forest Service Publications

Sampling the larval stages of the two-year cycle spruce budworm near Babine Lake, BC. 1964. Harris, J.W.E. The Forestry Chronicle 40(2): 195-201.

Year: 1964

Issued by: Pacific Forestry Centre

Catalog ID: 23976

Language: English

Availability: PDF (download)

Mark record


Methods of sampling the immature stages of the two-year-cycle spruce bud-worm, Choristoneura fumiferana (Clem.), were studied at Babine Lake in west-central British Columbia; this paper deals with the larval stages. No significant differences in the numbers of overwintering larvae per square foot of foliage were found between host species or size of sample branch. Significant differences existed between sample trees but a difference between crown levels was found only in the first-year population. No differences were found in the number of feeding larvae between host species, study areas, or crown sides. A difference between sample branch size was found only in the first-year population. Significant differences existed between crown levels, between overstory trees, and between the understory and overstory. An acceptable estimate of larval numbers at least for year-to-year comparison might be obtained by sampling one 18-inch branch tip from the mid-crown portion of as many trees as time permits.