WSU Extension

Hortsense

Cherry : Spider mites
(revision date: 2/14/2019)


Biology
Several species of spider mites can be found on cherry. They range in color from pale yellowish or green to red or brown. Spider mites feed on the leaves (typically on the underside), causing a whitish, yellow, or brown stippling. More severe damage results in leaves taking on a bronzed appearance. Heavy infestations may cause leaf drop. Spider mite feeding is usually accompanied by webbing on leaves and between leaves and twigs, although the European red mite produces smaller amounts of webbing than other species. Spider mite infestations are worse in hot, dry, dusty conditions.
Management Options

Non-Chemical Management
  • Provide proper culture for trees. Healthy plants are more tolerant of damage, while drought-stressed plants are more susceptible.
  • Predatory mites and insects such as ladybird beetles and green lacewings aid in control of spider mite populations. Avoid use of broad-spectrum insecticides which kill beneficials.
  • Hose mites from plants with a strong stream of water.
  • High levels of nitrogen in the foliage encourage spider mite reproduction. Switch to a slow-release or low-nitrogen fertilizer.
Select non-chemical management options as your first choice!

Chemical Management

Apply oils only during dormant or delayed dormant period. Other products should be applied when mites are present. Several applications may be necessary. 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.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Safer Brand Garden Defense Multi-Purpose Spray Conc [Organic]
    Active ingredient: clarified hydrophobic extract of neem oil  |  EPA reg no: 70051-2-42697
  • Safer Brand Insect Killing Soap with Seaweed Extract II [Organic]
    Active ingredient: potassium laurate  |  EPA reg no: 42697-59
  • This list may not include all products registered for this use.
Images
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Caption: Spider mites under microscope
Photo by: L.K. Tanigoshi
Caption: Spider mite damage on leaf
Photo by: A.L. Antonelli
Caption: Spider mite webbing
Photo by: A.L. Antonelli