SPATIAL ATTACK DYNAMICS AND IMPACT OF PISSODES TERMlNAUS IN THREE BlOGEOCLlMATlC ZONES IN SOUTHERN B.C

itself by the third growing season following attack. Therefore, it is critical to evaluate trees for past attacks when manipulating stand density and remove tre s with defects in the process. Weevil attack causes reduced height increment for two growing seasons, reducing potential height growth by approximately one third and one fifth in the year of attack and the year following attack, respectively. The selection of hosts by P. ferminalis appears to be mediated by a number of factors: relative tree size (height, dbh); growing space (APA); and genetic factors. The spatial pattern of host pines influences the attack pattern. The attack pattern of P. ferminalis is highly aggregated when host trees are highly aggregated. When the pattern of the host becomes more regular, because of juvenile spacing or planting, the attack pattern of P. ferminalis also tends to be more regular or random in pattern. ' zones. The stem defect formed as a result of P. ferminalis attack usually expresses