Ornamental Cherry: Apple-and-thorn skeletonizer

categories: Ornamental Cherry Ornamental Cherry Insects Ornamental trees Ornamentals

revision date: 2024-06-05 10:25

Apple-and-thorn skeletonizer caterpillar feeding on leaf with brown damage area.
Apple-and-thorn skeletonizer caterpillar feeding on leaf
Photo by: A.L. Antonelli


The apple-and-thorn skeletonizer is a yellow-green caterpillar with small black spots. As a young caterpillar it feeds on the underside of leaves. More mature caterpillars move to the upper surface of the leaf, use silk to tie the edges of the leaf together near the base, and feed inside the tent-like structure. Leaves are skeletonized, with all tissues eaten away except veins and the lower leaf surface. Skeletonized leaves turn brown and drop. The feeding caterpillars produce large quantities of webbing and frass (excrement). The adult apple-and-thorn skeletonizer is a small dark-brown moth. Apple, birch, hawthorn, mountain ash, and willow may also be attacked.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Remove caterpillars by hand. Pinch tied leaves to kill caterpillars.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Bacillus thuringiensis (Bt) will provide control to young feeding caterpillars.
  • Use a spreader-sticker with liquid Bt formulations.
  • Homeowners should not make foliar applications to trees over 10 ft tall.
  • Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.