Scale are tiny parasitic insects that adhere to plants and live off the plant’s sap. They look like bumps and are often mistaken for a disease. There are some 7,000 species of scale insects, varying greatly in color, shape and size, usually ranging from 1/16 – 1/8 inch.

Scale are usually divided into 2 groups: soft scale and armored scale. Soft scale are covered with a protective waxy substance and are somewhat easier to kill than armored scale, which secrete a hard shell over their bodies for cover. Mealybugs are also part of the scale family.

Scale eggs are laid under the female’s body. They are called crawlers when they first hatch, because the nymphs have legs at this point and crawl off to find their own spot to attach and feed. Control measures are most effective during the crawler stage.

Different species favor different plants. Plants frequently infested with scale include: Euonymous magnolia and fruit trees and shrubs
Control of Scale

Outdoor Plants:

Treat with dormant oil in late spring, just before the leaves unfurl. Scale can overwinter as nymphs or eggs tucked away in tree bark.
If you catch the problem early, pruning infected branches is often the easiest and surest solution.
Scale are preyed on by beneficial insects like soldier beetles, lady beetles and parasitic wasps.