Lettuce: Aphids

• Categories: Lettuce Lettuce Insects Vegetables
• Last review date: 2026-07-31 11:11

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. The ants may protect aphid colonies from predators.

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 help control small, localized infestations.
• Wash aphids from plants with a strong stream of water. This may be ineffective on the low, dense foliage of lettuce.
• Control honeydew-feeding ants.
• Provide proper nutrition. High levels of nitrogen in the foliage encourage aphid reproduction. Switch to a slow-release or low-nitrogen fertilizer when practical.
• Wash lettuce before eating.

Chemical Management

• Apply when aphids first appear.

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 BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic]
  Active ingredient: azadirachtin
  EPA registration number: 70051-6-42697
• Safer Brand Insect Killing Soap with Seaweed Extract II [Organic]
  Active ingredient: potassium salts of fatty acid
  EPA registration number: 42697-59
• This list may not include all products registered for this use.