WSU Extension


Caption: Aphid colony
Photo by: A.L. Antonelli
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Asparagus : Asparagus aphid
(revision date: 3/10/2017)

Asparagus aphids are small (1/16"), powdery gray to gray-green insects. They may be winged or wingless. They feed in colonies on the ferns of asparagus and are typically found at the base of leaves. Aphid feeding causes severe stunting of the foliage and gives fronds a tufted, blue-gray appearance. Shoots of mature plants are severely stunted. Seedling plants may be killed. Asparagus aphids produce honeydew, a sweet, sticky material which may attract ants or become covered with a growth of dark sooty mold. The aphids overwinter as eggs, which are laid on the ferns in the fall as the ferns begin to yellow. The eggs drop to the ground during the winter.
Management Options

Non-Chemical Management
  • Provide proper culture to help plants tolerate some damage.
  • Cut down and destroy fronds as soon as they begin to yellow to reduce numbers of overwintering eggs.
  • Prune out and destroy severely infested ferns when noticed.
  • Encourage natural enemies including ladybird beetles, lacewings, syrphid (hover) fly larvae, and parasitic wasps. Avoid use of broad-spectrum insecticides which kill beneficial insects.
  • Wash aphids from foliage with a strong stream of water.
Select non-chemical management options as your first choice!

Chemical Management

Apply when aphids are present. Insecticidal soaps may require more than one application. Read the product label for instructions.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • Surround At Home Crop Protectant
    Active ingredient: kaolin clay  |  EPA reg no: 61842-18-56872
  • This list may not include all products registered for this use.
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Caption: Aphid colony
Photo by: A.L. Antonelli
Caption: Aphid cast skins
Photo by: R.S. Byther