Viburnum: Bean aphids

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

Use Integrated Pest Management (IPM) for successful plant problem management.

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

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• 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

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

• Hi-Yield Dormant Spray
  Active ingredient: oil/pet distillate [EPA registration number: 7401-428]
• R-T-U Year-Round Spray Oil
  Active ingredient: oil/pet distillate [EPA registration number: 6218-78]
• Safer Brand BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic]
  Active ingredient: azadirachtin [EPA registration number: 70051-6-42697]
• Safer Brand Garden Defense Multi-Purpose Spray Concentrate [Organic]
  Active ingredient: clarified hydrophobic extract of neem oil [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]
• This list may not include all products registered for this use.