Filbert: Filbertworm
Photo by: K. Grey
Biology
The filbertworm is the larval stage of a gray to reddish moth. The adult moth has copper- to gold-colored bands across the forewings and a wingspread of approximately 1⁄2″. The female moth lays eggs on or near the developing nut.
Emerging caterpillars bore into the nut through the base of the husk. The caterpillars feed inside the nut, blackening and destroying the kernel. Mature caterpillars are pinkish to white and 1⁄2″ to 3⁄4″ long. They feed for three or four weeks before dropping to the ground to pupate.
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!
- Harvest nuts as early as possible. Dry nuts immediately after harvest to minimize damage.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Apply in early July and again three weeks later.
- NOTE: Esfenvalerate is toxic to bees.
- Do not apply products containing esfenvalerate on or near blooming plants.
- To minimize risk to bees, apply in the evening after bees have stopped foraging for the day.
- 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.
Additional Images
Photo by: K. Grey
Photo by: K. Grey
Photo by: K. Grey
Photo by: K. Grey
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Evidence of noncompliance may be reported through your local Extension office.