Willow: Satin moth
categories: Ornamental trees Ornamentals Willow Willow Insects
revision date: 2023-04-12 12:00
Photo by: A.L. Antonelli
Biology
The caterpillars of the satin moth feed on leaves of willows and poplars. They may also occasionally attack oak and aspen. The adult moth is satiny and pure white, with a wingspan of 1 1/2″ to 2″. The caterpillars are voracious feeders, sometimes causing severe defoliation of trees. Mature caterpillars are approximately 2″ long. They are black, with red and white patches and tufts of hairs along the sides.
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 caterpillars when practical. Wear gloves, as hairs may irritate the skin.
- Natural enemies, including a fly and several parasites, help control satin moth populations. Avoid use of broad-spectrum insecticides which may kill beneficial insects.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- Applications should only be made if defoliation begins to approach 25% of the canopy.
- If Bt is chosen, be sure to apply when insect is feeding.
- Best time is when caterpillars are young. 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.