Azalea Bark Scale: Appearance, Territory, Damage, and Life Cycle

Latin Name: Eriococcus Azaleae

Appearance: Azaleas are Rhododendron family landscape favorites with beautiful flowers in the spring and summer, as well as vibrant fall foliage. Although many Azaleas are native to the United States and are generally healthy landscape plants, they are vulnerable to Azalea Bark Scale, a pest that has evolved to feed on these flowering shrubs.

Eriococcus azaleae, adult female azalea bark scales, are dark red with short legs and antennae and long, thread-like mouthparts. The egg sac or ovisac, a white coating of felted or matted waxy threads, usually conceals the insect. The sac measures are approximately 1/8 inch long and 1/16 inch thick. Within the egg sac, reddish-purple eggs are laid, filling the hole left by the female’s diminishing body.

Hosts Plants: Examples include azaleas, rhododendrons, huckleberries, andromeda, hawthorn, poplar, and willow. Scales are like stressed trees for food. Even the best-cared-for trees can succumb to a scale infestation, therefore maintaining the health and wellbeing of your trees can help protect them from scale infestations.

Territory: It is native to the Pacific northwest.

Damage Insect Cause: A soft scale known as the azalea bark scale feeds by piercing its mouth and sucking sap from nearby trees and plants. Soft scale is distinguished by a thick waxy coating as opposed to armored scale, which has a thin hard coating.

The most effective weapons in your inventory for combating azalea illnesses’ black branches are horticultural oil or dormant oil and insecticidal soap. Remove any dead or seriously damaged azalea blackened branches and wipe away as much soot as you can with gloved hands. Thoroughly spray the plant, including the undersides of the leaves. Continue spraying regularly until September, then restart in early spring.

Life History and Habits: The length of a female bug is about 0.125 inches. The spring is when eggs are laid, and the summer is when they hatch. Being the most mobile stage of the scale insect’s life cycle, the larvae that emerge from the eggs are known as “crawlers.” Crawlers cling to the bark and eat in branch forks and cracks. The long, needle-like mouthparts of scale insects are used to drain plant juices from inside the plant. Scales that are (1/16-1/8) inches long are immature when they overwinter on the stem and grow swiftly by late May the following spring. In late June to early July, females produce masses of waxy, white eggs. Every year, there is one generation.