WSU Extension

Hortsense

Caption: Brown soft scales
Photo by: A.L. Antonelli
  
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Holly : Brown soft scale
(revision date: 2/14/2019)


Biology
Brown soft scales are yellowish to dark brown insects (adults are usually darker) up to approximately 1/8" in diameter. They are found mainly on the underside of leaves or on green twigs. Soft scales produce large amounts of honeydew, a sweet, sticky material which may attract ants or become covered with a growth of dark sooty mold. Heavy scale infestations can cause branches or whole plants to become wilted or yellowish or show other signs of stress. Brown soft scales are also common on camellia, dogwood, and daphne, as well as being serious pests of houseplants and greenhouse ornamentals.
Management Options

Non-Chemical Management
  • Prune and destroy heavily infested branches, when practical.
  • Minor infestations may be wiped off by hand when practical.
  • Ladybird beetles, parasitic wasps, and other natural enemies help control scale populations outdoors. Avoid use of broad-spectrum insecticides which kill these beneficial 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 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.

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
  • 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: Brown soft scales
Photo by: A.L. Antonelli