Pine: Pine aphid

categories: Conifers Pine Pine Insects

revision date: 2023-04-04 12:00

Pine needles covered in white deposits in frosty look.
Woolly pine aphid
Photo by: R. Portman

Biology

Pine aphids are long-legged dark green or brown aphids covered with a white, woolly material. They are found in colonies on the needles. The aphids produce large amounts of honeydew (a sweet, sticky material) which is often covered by a black growth of sooty mold. Heavy aphid infestations may cause trees to turn yellowish, but otherwise cause only minor damage.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Avoid use of broad-spectrum insecticides which kill predators and parasites, including ladybird beetles, green lacewings, and parasitic wasps.
  • Reduce levels of nitrogen in foliage to decrease aphid reproduction. Switch to a slow-release or low-nitrogen fertilizer.
  • Prune and destroy heavily infested branches.
  • Hose aphids from trees with a strong stream of water, when practical.

Chemical Management

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

  • Thorough coverage of the foliage is important, including thorough penetration of needle clusters.
  • Apply one of the following if aphids begin to build up.
  • 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.