WSU Extension

Hortsense

Caption: Cottony camellia scale on holly
Photo by: A.L. Antonelli
  
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Camellia : Cottony camellia scale
(revision date: 2/14/2019)


Biology
The cottony camellia scale is a flat brownish or yellowish insect. The scales overwinter on twigs or evergreen leaves. In the spring, adult females lay cottony egg masses on the underside of leaves. Crawlers (young scales) feed on the underside of leaves. Cottony camellia scales produce large amounts of honeydew, a sweet sticky material which is often covered with a growth of black sooty mold. Foliage with scale infestations may turn yellowish or pale in color. The cottony camellia scale is also found on yew and holly.
Management Options

Non-Chemical Management
  • Remove any egg masses found on leaves.
  • Hand-pick scales when practical to control minor infections.
  • Where practical, prune out and destroy heavily infested leaves and branches.
  • Encourage natural predators of scales such as ladybird beetles and their larvae, and parasitic wasps. Avoid use of broad-spectrum insecticides which kill these insects.
Select non-chemical management options as your first choice!

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 oil sprays only on overwintering nymphs. Test for sensitivity on camellia before applying insecticidal soaps.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • All Seasons Horticultural & Dormant Spray Oil Conc [Organic]
    Active ingredient: oil/pet distillate  |  EPA reg no: 4-80
  • Bonide Systemic Insect Control
    Active ingredient: acephate  |  EPA reg no: 239-2461-4
  • Hi-Yield Dormant Spray
    Active ingredient: oil/pet distillate  |  EPA reg no: 7401-428
  • R-T-U Year-Round Spray Oil
    Active ingredient: oil/pet distillate  |  EPA reg no: 6218-78
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • Safer Brand Insect Killing Soap Conc II [Organic]
    Active ingredient: potassium laurate  |  EPA reg no: 42697-60
  • This list may not include all products registered for this use.
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Caption: Cottony camellia scale on holly
Photo by: A.L. Antonelli