Apple-and-thorn skeletonizer

In mid-summer you will spot groups of small yellowish-green larvae skeletonizing leaves on serviceberry, hawthorn, birch, and other plants, leaving vein structure intact. Damaged foliage looks lacy and translucent. These sawfly larvae feed in clusters on upper surfaces, with affected branches appearing scorched in sunny, warm microclimates of Puget Sound region.

Hand-pick leaf clusters with visible larvae and destroy them; works well on smaller ornamental plants. Prune infested branch tips if damage is severe. Encourage parasitic wasps and predatory beetles by avoiding broad-spectrum insecticides. Apply insecticidal soap directly to larvae in early July before they pupate. Cosmetic pest; plants recover completely after defoliation.