Dogwood: Lecanium scale

categories: Dogwood Dogwood Insects Ornamental trees Ornamentals

revision date: 2024-06-05 02:04

Yellow pencil pointing to Lecanium cales on twig shown on a black background.
Lecanium scales on twig
Photo by: R.S. Byther


Lecanium scales are rounded brown (or mottled) insects. Adults are from 1/8″ to 1/4″ in diameter. Lecanium scales produce large amounts of sticky honeydew, which may have sooty mold growing on it. They overwinter on the bark, but the crawlers feed on the underside of leaves from May to August (approximately). Scales may be spread from infested plants by people, other insects, wind, and birds.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Natural predators such as ladybird beetles and green lacewings may greatly reduce the number of crawlers.
  • If the infestation is minor, scales may be wiped from the bark or leaves.
  • Prune and destroy heavily infested branches.

Chemical Management

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

  • Scout for crawlers.
  • Insecticide applications can be effective when applied to control the immature crawlers stage, usually in late spring to early summer.
  • Oils are effective in the delayed dormant period.
  • Use superior type oil sprays only on overwintering nymphs.
  • 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.