Asparagus: Asparagus aphid

Aphid colony on leaf.
Aphid colony on leaf
Photo by: A.L. Antonelli

Biology

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

See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.

Non-chemical Management

Select non-chemical management options as your first choice!

  • 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.

Chemical Management

IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :

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

Approved Pesticides

If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.

Additional Image


cougar head logo

WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.