Yew: Cottony camellia scale

• Categories: Conifers Ornamentals Yew Yew Insects
• Last review date: 2025-12-03 10:06

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

See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.

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

• 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

If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.

• All Seasons Horticultural and Dormant Spray Oil Concentrate [Organic]
  Active ingredient: mineral oil
  EPA registration number: 4-80
• Hi-Yield 55% Malathion Spray
  Active ingredient: malathion
  EPA registration number: 7401-10-34911
• R-T-U Year-Round Spray Oil
  Active ingredient: mineral oil
  EPA registration number: 6218-78
• Safer Brand BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic]
  Active ingredient: azadirachtin
  EPA registration number: 70051-6-42697
• Safer Brand Insect Killing Soap Concentrate II [Organic]
  Active ingredient: potassium salts of fatty acid
  EPA registration number: 42697-60
• This list may not include all products registered for this use.