Shothole borer

Adult Scolytus rugulosus create shot-like holes in bark and wood of cherry and plum twigs and branches in Western Washington, with holes occurring in clusters; these are entrance or exit holes from brood chambers. Larval feeding between bark and wood girdles limbs and trunks, eventually killing affected growth. Most damage occurs on injured, stressed, or neglected trees rather than vigorous plants.

Keep trees healthy with proper pruning, irrigation, and balanced fertilization to enable sap and resin plugging of bore holes. Remove dead wood and prune infested branches. Dormant oil spray in early spring coats emerging beetles. Avoid late spring and summer pruning when beetles are active.