Crabapple: Apple-and-thorn skeletonizer

categories: Crabapple Crabapple Insects Ornamental trees Ornamentals

revision date: 2023-12-02 09:17

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 adult of the apple-and-thorn skeletonizer is a small dark-brown moth. It overwinters as a pupa or an adult, with the females laying eggs in the spring. The caterpillars are yellow-green in color, have black spots and brown heads, and feed on the leaves of several plants including crabapple, apple, pear, cherry, and hawthorn. Characteristic damage includes skeletonized leaves, or leaves that are rolled into a cone and tied with webbing. Damaged leaves turn brown and drop prematurely.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Hand-pick and destroy caterpillars.
  • Pinch caterpillars inside rolled leaves or prune and destroy infested twigs.

Chemical Management

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

  • Pesticide recommendations are for flowering (non-edible) crabapples.
  • Apply soon after petal fall, late May, June, July and August.
  • One or two applications however are usually enough.
  • Bacillus thuringiensis (Bt) will provide control of 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.