Ornamental Cherry: Apple-and-thorn skeletonizer
Photo by: A.L. Antonelli
Biology
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
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
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: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- 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
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.