Arborvitae: Juniper scale
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Biology
Juniper scale is a small, round, white to gray scale with a yellow dot at the center. Leaves, twigs and branches may be attacked.
Symptoms of scale feeding include loss of normal color and luster of foliage, lack of new growth, and yellowing and death of branches. Severe infestations are rare but may kill plants.
The scales excrete large amounts of honeydew, a sweet, sticky material. Honeydew may attract ants or may become covered with a growth of dark sooty mold.
Red cedars and Pfitzer, Irish, and Savin junipers are also commonly attacked.
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!
- Ladybird beetles and parasitic wasps help control scale infestations.
- Minor infestations may be wiped off by hand, when practical.
- Prune and destroy heavily infested branches to help control localized infestations.
- Provide proper culture. Healthy plants are more able to tolerate damage.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Make applications to control the immature crawlers in late spring to early summer.
- Do not apply soap products to plants stressed by drought or when tender new foliage is present.
- Do not apply soap in full sun or when temperatures exceed 90° F.
- When using Safer Brand Insect Killing Soap Conc II, test a small area for sensitivity before application.
- 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.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.