Carpenterworm

Carpenterworm larvae bore large tunnels through the heartwood of hardwood trees, leaving round exit holes up to a quarter inch wide and accumulations of coarse frass at the base of the trunk. You will notice sap oozing from entry points and sawdust-like debris on bark and around the root flare. Damage develops over several years as larvae tunnel through the wood of oaks, maples, willows, and other broadleaf trees across Western Washington.

Maintain tree vigor through proper irrigation and soil care to enable natural defenses. Probe accessible tunnels with a flexible wire to kill larvae. Inject beneficial nematodes into fresh bore holes and seal the openings. Avoid wounding trees during the adult moth flight season in late spring and summer. Remove severely compromised trees that pose structural hazards.