Sycamore: Aphids

categories: Ornamental trees Ornamentals Sycamore Sycamore Insects

revision date: 2023-04-04 12:00

Aphid colony on leaf.
Aphid colony on leaf
Photo by: A.L. Antonelli

Biology

Aphids are soft-bodied insects that typically feed on leaves and succulent stems. They may vary in color from pale green or reddish to dark or black. Aphids are usually less than 1/8″ in length. Aphid feeding is often accompanied by production of honeydew, a sweet, sticky substance. Honeydew can develop a dark growth of black sooty mold and may attract ants. White cast skins shed by aphids are often found on leaves, as well.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Hand-wipe or prune to control small, localized infestations when practical.
  • Wash aphids from foliage with a strong stream of water.
  • Encourage natural predators including ladybird beetles, lacewings, syrphid (hover) fly larvae, and predatory wasps. Avoid use of broad-spectrum insecticides which kill these beneficial insects.
  • Control honeydew-feeding ants, which may protect aphid colonies from predators.
  • 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 is important, including lower leaf surfaces.
  • Apply one of the following if aphid build-up is noticed.
  • 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.

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