Spruce: Pine needle scale

categories: Conifers Ornamentals Spruce Spruce Insects

revision date: 2023-02-07 12:00

On a black background, close-up of three pine needles, two with white scale compared to one without.
Photo by: A.L. Antonelli close-up.
Photo by: R.S. Byther

Biology

Pine needle scale occurs on the needles of spruce, pine, and true fir. The elongate, flattened scales are white and about 1⁄16″ long. Infested needles are mottled yellow at first, then turn completely yellow and finally brown. Light infestations cause little damage. In heavy infestations the tree may appear “flocked” or “frosted”. Severe attacks by pine needle scale may kill branches or the whole tree.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • On small, lightly infested trees, hand-picking may help remove scales.
  • Where practical, prune and destroy heavily infested branches.

Chemical Management

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

  • Controls are effective only if applied during the early mobile crawler stage of insect development in early spring.
  • Horticultural oils, soap-based products and some other products may cause discoloration of spruce needles, particularly on Colorado blue spruce.
  • DO NOT APPLY Safer Brand Insect Killing Soap Concentrate II to Colorado blue spruce.
  • Read labels carefully and test on a small area before application.
  • 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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