WSU Extension


Peach : Aphids
(revision date: 3/22/2021)

The green peach aphid is a soft-bodied, green aphid up to 1/8" in length. It is typically found on peach leaves in the spring, where it feeds on sap sucked from the plant tissues. Heavy infestations can result in curled leaves and death of forming flowers and fruit. Nectarine fruits in particular may be severely damaged by aphid feeding. Aphids produce honeydew, a sweet, sticky material which may attract ants or become covered with a growth of dark sooty mold. The green peach aphid moves to and feeds on vegetable crops and weeds during the summer. It is an important vector (carrier) of several virus diseases, including the Leafroll Virus of potato.
Management Options

Non-Chemical Management
  • Control weeds.
  • Encourage natural predators including ladybird beetles, lacewings, syrphid (hover) fly larvae, and parasitic wasps. Avoid use of broad-spectrum insecticides which kill beneficial insects.
  • Hand-wipe or prune to control small, localized infestations when practical.
  • Wash aphids from trees with a strong stream of water.
  • Control honeydew-feeding ants, which may protect aphid colonies from predators.
  • Provide proper nutrition. High levels of nitrogen encourage aphid reproduction. Switch to a slow-release or low-nitrogen fertilizer.
Select non-chemical management options as your first choice!

Chemical Management

Oils should only be applied during dormant or delayed dormant period. Other products can be used during the growing season following the label instructions. Soaps may require several applications. See label for minimum time from last application to harvest. 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.
  • Bayer Advanced Natria Neem Oil Conc [Organic]
    Active ingredient: clarified hydrophobic extract of neem oil  |  EPA reg no: 70051-2-72155
  • Bug Buster-O [Organic]
    Active ingredient: pyrethrins  |  EPA reg no: 1021-1771-54705
  • NIMBIOSYS Neem Oil [Organic]
    Active ingredient: neem oil, cold pressed  |  EPA reg no: 84181-2
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • Safer Brand Insect Killing Soap with Seaweed Extract II [Organic]
    Active ingredient: potassium salts of fatty acid  |  EPA reg no: 42697-59
  • Year-Round Spray Oil Kills Garden Insects-OMRI-[Organic]
    Active ingredient: mineral oil  |  EPA reg no: 6218-71
  • This list may not include all products registered for this use.
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Caption: Green peach aphid
Photo by: Unknown
Caption: Aphid colony
Photo by: Unknown
Caption: Aphid cast skins
Photo by: R.S. Byther