Dogwood sawfly

Dogwood sawfly larvae feed on dogwood foliage in Western Washington, creating skeletonized areas where they consume leaf tissue while leaving veins intact. You will see lacy, brown-looking leaves that may eventually drop. Damage appears in early summer as larvae move through new growth. Cornus species including Cornelian cherry and kousa dogwood are affected. Infested trees look unsightly but usually recover as they push new growth.

Monitor new foliage regularly starting in late spring for the first appearance of skeletonization. Prune out lightly infested branches and remove them from the site. Bacillus thuringiensis (Bt) applied early when you see young larvae feeds on leaf tissue with minimal impact on beneficial insects. Most dogwoods tolerate leaf loss without serious harm. Allow natural parasitoid populations to establish; they provide effective control over time without intervention.