WSU Extension

Hortsense

Viburnum
 
Disease
Bacterial blight (Leaf spot) 
Leaf spot 
Powdery mildew 
Ramorum leaf and shoot blight (Sudden oak death) 
Shoot blight (Gray mold) 
Insect
Bean aphids 
Root weevils 
Viburnum leaf beetle 



print version| pdf version| email url    
Caption: Bean aphid
Photo by: K. Grey
  
Viburnum : Bean aphids
(revision date: 4/11/2018)


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


Non-Chemical Management
  • 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.
Select non-chemical management options as your first choice!

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.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bonide Systemic Insect Control
    Active ingredient: acephate  |  EPA reg no: 239-2461-4
  • Hi-Yield Dormant Spray
    Active ingredient: oil/pet distillate  |  EPA reg no: 7401-428
  • R-T-U Year-Round Spray Oil
    Active ingredient: oil/pet distillate  |  EPA reg no: 6218-78
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • Safer Brand Garden Defense Multi-Purpose Spray Conc [Organic]
    Active ingredient: clarified hydrophobic extract of neem oil  |  EPA reg no: 70051-2-42697
  • Safer Brand Insect Killing Soap Conc II [Organic]
    Active ingredient: potassium laurate  |  EPA reg no: 42697-60
  • This list may not include all products registered for this use.
Images

+ Show larger images

 
Caption: Bean aphid
Photo by: K. Grey