Corn: Corn aphids

• Categories: Corn Corn Insects Vegetables
• Last review date: 2026-08-29 09:26

Biology

Aphids are small, soft-bodied, pear-shaped insects. They may vary in color from yellow to green to dark.

Aphids typically feed in colonies on the leaves, often preferring the newer growth. Infested leaves turn yellow and may wilt or show other signs of water stress.

Feeding aphids often produce large amounts of honeydew, a sweet, sticky material which may attract ants or become covered with a dark growth of sooty mold.

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!

• Encourage natural enemies including ladybird beetles, lacewings, syrphid (hover) fly larvae, and parasitic wasps. Avoid use of broad-spectrum insecticides which kill beneficial insects.
• Hand-wipe to control small, localized infestations when practical.
• Wash aphids from plants with a strong stream of water.
• Control honeydew-feeding ants, which may protect aphid colonies from predators.
• Provide proper nutrition. High levels of nitrogen in the foliage encourage aphid reproduction. Switch to a slow-release or low-nitrogen fertilizer when practical.

Chemical Management

• Thorough coverage of the foliage is important, including lower leaf surfaces.
• Apply in early morning or during the evening when bees are not present.
• Do not apply unless leaves are dry.
• Read the product label for timing between last application and harvest.

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.

• Safer Brand Insect Killing Soap with Seaweed Extract II [Organic]
  Active ingredient: potassium salts of fatty acid
  EPA registration number: 42697-59
• Whitney Farms Insecticidal Soap [Organic]
  Active ingredient: potassium salts of fatty acid
  EPA registration number: 67702-21-91161
• Azera Gardening [Organic]
  Active ingredient: azadirachtin, pyrethrins
  EPA registration number: 1021-1872
• This list may not include all products registered for this use.