WSU Extension


Caption: Pine eriophyid mite damage
Photo by: R.S. Byther
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Pine : Eriophyid mites
(revision date: 3/10/2017)

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

Non-Chemical Management
  • Prune out rosettes and severely infested branches when possible.
Select non-chemical management options as your first choice!

Chemical Management

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.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • GardenTech Sevin Conc Bug Killer
    Active ingredient: carbaryl  |  EPA reg no: 264-334-71004
  • This list may not include all products registered for this use.
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Caption: Pine eriophyid mite damage
Photo by: R.S. Byther
Caption: Pine eriophyid mite rosetting damage
Photo by: R.S. Byther