Pear: Spider mites

Biology

Several species of spider mites may be found on pear leaves, including the twospotted and McDaniel spider mites and the European red mite. They may be various colors including yellow, greenish, brown, or red. All species feed on the leaves, causing a whitish to yellow stippling. More severe damage results in leaves taking on a bronzed appearance. Infested pear leaves often develop small to large necrotic brown spots during hot weather. This is known as transpiration burn and is a common symptom of mite feeding on pears. Severe cases of transpiration burn can result in premature leaf drop. Most spider mites spin webbing which may be found on the lower leaf surfaces and between leaves and twigs. The European red mite typically produces smaller amounts of webbing than other species.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

• 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 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.

Chemical Management

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

• Apply superior type oils in early spring just prior to bud swell to manage overwintering eggs for European red mite control.
• Apply insecticidal soap for other mites. Insecticidal soap sprays must cover all leaf surfaces to be effective.
• 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.

• Hi-Yield Dormant Spray
  Active ingredient: oil/pet distillate [EPA registration number: 7401-428]
• R-T-U Year-Round Spray Oil
  Active ingredient: oil/pet distillate [EPA registration number: 6218-78]
• Safer Brand Insect Killing Soap with Seaweed Extract II [Organic]
  Active ingredient: potassium salts of fatty acid [EPA registration number: 42697-59]
• This list may not include all products registered for this use.

Additional Images