A METHOD OF ESTIMATION OF THE TOTAL DENSITY OF INFESTATION OF SCOTS PINE STEMS BY THE LESSER PINE SHOOT BEETLE (TOMICUS MINOR)

摘要

Results of studies on colonization of Pinus sylvestris trap trees by Tomicus minor are presented. The scheme of spatial distribution of density of this bark beetle nests agrees with spatial distribution of colonization frequency in individual sections of the bole. Beetles most frequently colonized the middle parts of the bole, occurring most frequently (59.5%) and reaching the greatest density of nests (14.8%) in the eighth one-meter section of the trap tree bole. The linear relationships between nest numbers in distinguished one-meter sections of the bole and the total density of the bole colonization are determined. In the case of the eighth section, counting from the butt, the correlation was strongest (R~(2) = 0.5877, P < 0.0001), and the mean relative error of estimation was smallest (49.46%).