WSU Extension


Spinach or beet leafminer 

print version| pdf version| email url    
Caption: Aphid colony
Photo by: A.L. Antonelli
Spinach : Aphids
(revision date: 3/22/2021)

Aphids are small, soft-bodied, pear-shaped insects. They vary in color from yellow to light or dark green. 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 honeydew-feeding ants may protect aphid colonies from predators.
Management Options

Non-Chemical Management
  • 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 or pick leaves to help control small, localized infestations, if practical.
  • Wash aphids from plants with a strong stream of water. This may be ineffective on the low foliage of spinach.
  • 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 leaves before eating.
Select non-chemical management options as your first choice!

Chemical Management

Thorough coverage of foliage is important, including lower leaf surfaces. Do not apply unless leaves are dry. Read the product label for timing between last application and harvest. Insecticidal soaps may require more than one application. Apply when aphids begin to build up.

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
  • Safer Brand Insect Killing Soap Conc II [Organic]
    Active ingredient: potassium salts of fatty acid  |  EPA reg no: 42697-60
  • Safer Brand Insect Killing Soap with Seaweed Extract II [Organic]
    Active ingredient: potassium salts of fatty acid  |  EPA reg no: 42697-59
  • 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.

+ Show larger images

Caption: Aphid colony
Photo by: A.L. Antonelli
Caption: Aphid cast skins
Photo by: R.S. Byther