Scale is a word used to describe nearly 8,000 different species of insects. While they vary greatly in appearance, many Scales are significant pests. Female Scales develop a protective covering, and become immobile (sessile), attached to the plant they are feeding on. Juvenile scales are very small, have legs and are called crawlers.
Scales are divided into two types: armored and soft. Armored Scales are less than 1/8 inch wide and have a hard, waxy covering that is separate from the insects body. Soft Scales, such as Cottony Cushion Scale, are usually less than 1/2- inch in diameter and have a soft, waxy, sometimes cottony layer over the insect’s body.
Damage From Scales
Scales suck the juices from plants causing reduced vigor, yellowing foliage and premature leaf drop. Scales can also exude honeydew, a sweet, sticky substance that attracts Wasps, Ants and Bees and can serve as a medium on which Sooty Mold can grow.
Insecticidal sprays used to control Scales are most effective during the immature crawler stage, which usually occurs from late winter to early summer. Contact your local cooperative extension for precise spray timing recommendations.
Where Scales are Found Geographically
Various types of Scales can be found throughout the United States.
Related or Similar Pests
- Prune to keep plants open in the center so sprays and beneficial insects can easily reach inside the plant where scales can hide in crotches and crevices.