Euonymus: Euonymus scale

categories: Euonymus Euonymus Insects Ornamentals Shrubs

revision date: 2022-12-01 12:00

Euonymus scale on leaf.
Euonymus scale
Photo by: Unknown

Biology

Euonymus scale females are dark, 1/16″ long, and mussel-shaped. The males are narrow, elongate, and white. Euonymus scales are found on both leaves and stems. Infested leaves develop yellow to white spots from scale feeding. Crawlers are orange and first emerge in the spring (there are 2-3 generations/year) from beneath the shells of overwintering mature females. Euonymus scale is also reported to infest bittersweet (Celastrus spp.) and pachysandra.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Plant resistant species. Euonymus alata (especially ‘Compacta’) and E. fortunei ‘Acutus’ are seldom infested. Several other species will tolerate scale feeding.
  • Do not plant E. japonica (evergreen euonymus), as it is extremely susceptible to scale infestations.
  • Prune and destroy twigs with isolated heavy infestations.
  • Hand-wipe to help control small infestations, when practical.
  • Natural predators may help control infestations, but may not prevent damage.

Chemical Management

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

  • Apply to control the immature crawler stage in May and again in June or July if needed.
  • 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.