Azalea: Azalea bark scale

categories: Azalea Azalea Insects Ornamentals Shrubs

revision date: 2022-11-30 12:00

Azalea bark scale and sooty mold.
Azalea bark scale and sooty mold
Photo by: A.L. Antonelli

Biology

The azalea bark scale is a soft scale resembling mealybugs. Red females cover themselves and their eggs with a white, waxy, protective coating. Cottony masses of the scales are often located on twigs and in the forks of the branches. Sticky honeydew is excreted by the pests, and may have black sooty mold growing on it.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Provide proper culture, including fertilization and irrigation. Healthy plants are more able to tolerate scale damage.
  • Several species of ladybird beetles and parasitic wasps help control scale populations. Avoid use of broad-spectrum insecticides which can kill these predators.
  • Where the infestation is limited, it may be possible to hand-wipe or prune and destroy stems that are severely affected.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Apply treatment to control young crawlers usually in early July, but may also be controlled through September.
  • Treatment can also be made in March and early April.
  • Monitor populations so that applications can coincide with egg hatch.
  • Test for sensitivity on azalea before applying insecticidal soaps.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.