SPATIAL DYNAMICS AND IMPACTS OF PISSODES TERMINALIS (COLEOPTERA, CURCULIONIDAE) IN REGENERATING STANDS OF LODGEPOLE PINE

The spatial distribution of lodgepole pines attacked by Pissodes termi nalis Hopping was analysed in spaced and unspaced plots located in the Interior Douglas-fir biogeoclimatic zone in south central British Col umbia. The mean area potentially available (APA) described by Voronoi polygons around all attacked trees (7.2 +/- 0.2 m(2)) was significantl y greater than the mean APA of unattacked trees (5.5 +/- 0.2 m(2)) in the spaced plot. The mean nearest neighbor distance of attacked trees also was significantly greater than that of unattacked trees in the sp aced plot. In the unspaced plot, all trees in the plot (attacked and u nattacked), and just attacked trees, approached a clumped distribution . In the spaced plot the attack pattern in any given year was clumped, but cumulatively, the trees attacked by P. terminalis approached a ra ndom distribution. The largest trees were most likely to be attacked a nd the most noticeable defect was a crook. Height loss due to weevil a ttack was 31.4% of the annual potential height increment in the year o f attack, and 17% in the year following attack. Trees with ample growi ng areas are more likely to sustain severe damage due to weevil attack s. Delaying spacing until trees are > 15 years old is recommended to r educe the impact of weevil attack.