Scale Insects are a wide variety of insects that don’t move as adults, have some kind of covering for their bodies, and feed on the sap of plants. There are two main categories of scales, soft and armored (or hard) scales.
Soft scales form a waxy coating that is attached to their bodies. They also produce honeydew, their sugary pee that can lead to sooty mold. Armored scales produce a more shell-like scale that is not attached to their bodies. They usually have one or two generations a year, where the female lays eggs under her scales. “Crawlers” then emerge, which are capable of crawling around before attaching to a new site on the plant. Some common scales include Euonymus scale, oak lecanium scale, and pine needle scale.
Small numbers of scales are often present on trees and shrubs and do not need to be controlled. If the populations grow to damaging numbers, controls should be used. Bonide’s “For All Seasons” can be used when crawlers are present, so the scale species will have to be identified to find the spraying window. Imidacloprid can be used to control most soft scales systemically but not armored scales such as Euonymus scale.