Pine: Spider mites
Photo by: L.K. Tanigoshi
Biology
Spruce spider mites feed on older needles, causing yellowish to gray stippling (tiny spots) and needle chlorosis or yellowing.
Fine webbing is usually present on infested needles and twigs. The mites are tiny and greenish or yellowish in color.
They overwinter as eggs on the host and can hatch as early as April or May.
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!
- Wash mites off trees with a strong stream of water where possible.
- Reduce levels of nitrogen in foliage to decrease spider mite reproduction. Switch to a slow-release or low-nitrogen formula.
- Avoid use of broad-spectrum insecticides which kill parasites and predatory mites.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Apply oils in early spring to smother over-wintering eggs.
- Begin monitoring for spider mites in the late spring or especially during hot weather.
- Apply one of the following for nymph or adult mites. 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 Image
Photo by: Unknown
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.