Pine: Eriophyid mites

categories: Conifers Ornamentals Pine Pine Insects

revision date: 2023-02-07 12:00

Yellowing needles at tip of pine branch shown against a black background.
Pine eriophyid mite damage
Photo by: R.S. Byther

Biology

Eriophyid mites are tiny, wormlike, whitish or tan mites which feed under bud scales or in the needle sheaths, often between the needle bases. Symptoms of eriophyid mite infestations include yellowing, distortion, and stunting of new needles, and development of numerous buds where a bud has been infested (rosetting). Severe infestations may kill needles and cause needle drop, leaving naked branch tips. Rosettes may develop into witches’ broom growths. Two-needle pines, particularly lodgepole or shore pine, are affected.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Prune out rosettes and severely infested branches when possible.

Chemical Management

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

  • The Sevin (carbaryl) products must be applied with superior dormant oil.
  • Apply three times at one week apart from mid-May into early June when new candles have elongated.
  • Carbaryl is particularly dangerous to honeybees since it does not immediately kill them. They return to the hive with the poison and distribute it within. Avoid carbaryl if there is any possibility of pesticide drifting onto nearby blooming plants.
  • These products are toxic to bees.
  • 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.

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