Sequoia pitch moth

Clear-winged moths resembling yellow jacket wasps lay eggs on pines in Western Washington, with yellowish larvae bearing reddish-brown heads tunneling into the cambial layer. Distinctive masses of pitch and frass develop at feeding sites, soft and whitish-pink when fresh, hardening and darkening with age; resin masses can reach 1-2 inches in diameter.

Healthy trees are rarely attacked; infestations follow pruning wounds or mechanical damage. Avoid spring and summer pruning when moths are flying. Keep trees vigorous through irrigation and avoid stress. Remove pitch masses to prevent larval development. Prune severely infested branches.