Viburnum: Bean aphids

• Categories: Ornamentals Shrubs Viburnum Viburnum Insects
• Last review date: 2026-08-29 08:37

Biology

Bean aphids are soft-bodied dark green to black insects commonly found on the undersides of leaves and on new growth. They often occur in dense colonies.

Heavy aphid feeding may distort shoot tips and leaves, and leaves may turn yellow, wilt, or show other signs of stress.

Bean aphids typically produce large amounts of honeydew, a sweet, sticky material. It can attract honeydew-feeding ants, which protect aphid colonies from predators. Honeydew may also become covered with a dark, unsightly growth of sooty mold.

Viburnum is a winter host for the aphids, which may be found on various vegetables in the summer, including beans, lettuce, and squash.

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!

• Viburnum davidii is not infested. The “snowball” viburnums are preferred hosts.
• Hand-wipe or prune to control small, localized infestations when practical.
• Wash aphids from foliage with a strong stream of water.
• Encourage predators such as ladybird beetles, lacewings, syrphid (hover) fly larvae, and predatory wasps. Avoid use of broad-spectrum insecticides which kill these beneficials.
• 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.

Chemical Management

• Thorough coverage of the foliage including lower leaf surfaces is important when using foliar sprays.
• Follow label instructions for products applied as a drench.
• Apply one of the following if aphid numbers begin to increase.
• Homeowners should not make foliar applications to trees over 10 ft tall.
• Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

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.

• Hi-Yield Dormant Spray
  Active ingredient: Paraffinc oil
  EPA registration number: 7401-428
• R-T-U Year-Round Spray Oil
  Active ingredient: mineral oil
  EPA registration number: 6218-78
• Safer Brand Neem Oil Concentrate
  Active ingredient: NEEM Oil, Clarified Hydrophobic Extract
  EPA registration number: 70051-2-42697
• Safer Brand Insect Killing Soap Concentrate II [Organic]
  Active ingredient: potassium salts of fatty acid
  EPA registration number: 42697-60
• Azera Gardening [Organic]
  Active ingredient: azadirachtin, pyrethrins
  EPA registration number: 1021-1872
• This list may not include all products registered for this use.