Subalpine fir (Abies lasiocarpa (Pinaceae)) forests in British Columbia (B.C.) are increasingly climate-stressed and vulnerable to pest damage. Following a drought in southern B.C., the balsam bark weevil, Pissodes striatulus (Coleoptera: Curculionidae), was observed attacking and killing mature subalpine fir trees. This study documents P. striatulus as a tree-killing insect, often associated with western balsam bark beetle (Coleoptera: Curculionidae), which is considered the most destructive insect pest of subalpine fir. In B.C., this weevil displays a one-year life history, overwintering as late-instar larvae in the bark and as newly emerged or older adults in the duff at the base of attacked trees. Attacked trees are difficult to identify until the tree becomes chlorotic and dies. Larvae may excavate diagnostic chip cocoons in the sapwood before pupating, but most complete their development in the phloem where their galleries quickly become obscured by woodborer activity and other insects. Pissodes striatulus was found at 71% of sites surveyed, and 19% of trees sampled were killed by the weevil acting as the primary invader. The weevil uses downed trees, slash, and susceptible live trees, is long lived, and can switch from primary to secondary attacker, demonstrating its capacity to adapt to available and changing conditions
