Yew: Cottony camellia scale

categories: Conifers Ornamentals Yew Yew Insects

revision date: 2023-04-04 12:00

Yew needles with white cottony scale.
Cottony camellia scale on yew
Photo by: A.L. Antonelli

Biology

The adult cottony camellia scale is a flat, oval, brownish insect. It is also found on holly and camellia. The scales overwinter on twigs or needles. In the spring, adult females lay cottony egg masses on the underside of needles. The yellowish crawlers (immature scales) feed on the needles. Feeding cottony camellia scales produce large amounts of honeydew, a sweet, sticky material which often develops a growth of dark sooty mold. Honeydew may also attract ants. Foliage with scale infestations may turn yellowish or pale. The cottony camellia scale is also commonly found on holly and camellia.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Prune out and destroy heavily infested twigs, when practical.
  • Encourage natural enemies of scales, including ladybird beetles and parasitic wasps. Avoid use of broad-spectrum insecticides which kill these beneficial insects.
  • Control honeydew-feeding ants, which may protect scales from predators.

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.