Crabapple: Spider mites

Biology

Spider mites on crabapple vary in color. They may be yellow, green, red or brown. They have eight legs and are very small, appearing as moving dots when viewed through a hand lens. Spider mites often feed on the underside of leaves, causing yellowish to bronze stippling or speckling. Fine webbing may be present on leaves or in branch crotches. Hot, dry, dusty conditions are especially favorable for development of severe infestations.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Wash spider mites from plants with a strong stream of water.
• Provide adequate irrigation and proper plant nutrition. High levels of nitrogen in the foliage encourage mite reproduction. Switch to a slow-release or low-nitrogen fertilizer.
• Natural predators such as ladybird beetles and predacious mites help control spider mite populations. Avoid use of broad-spectrum insecticides which kill beneficials.
• Plant ground covers to help prevent dusty conditions.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• Pesticide recommendations are for flowering (non-edible) crabapples.
• Apply in late spring if mites are present and moving.
• Horticultural oils are most effective against the egg stage (delayed dormant period) of the mite life cycle and only on European Red mites not on 2-spotted mite.
• 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.

• All Seasons Horticultural and Dormant Spray Oil Concentrate [Organic]
  Active ingredient: mineral oil/pet distillate [EPA registration number: 4-80]
• Hi-Yield Dormant Spray
  Active ingredient: oil/pet distillate [EPA registration number: 7401-428]
• Safer Brand Insect Killing Soap Concentrate II [Organic]
  Active ingredient: potassium salts of fatty acid [EPA registration number: 42697-60]
• This list may not include all products registered for this use.

Additional Images