Scale

Scale are typically immobile pests that suck plant juices, taking vital sugars away from the plant. They are sometimes hard to identify and often mistaken for natural deformities on plants like galls. Scale have waxy coverings that protect them from most insecticides, so it is ideal to treat them while they are in the larvae, or crawler stage.

Scale insects can be serious pests on trees, shrubs, and other perennials. Most people don't recognize them as an insect because most immatures (nymphs) are immobile, wingless, and lack a separate head or other recognizable body parts.

Scale insects can be broken into two general categories: soft and armored (hard). Soft scales secrete a soft, waxy layer over them that cannot be detached from their body. They often move between branches and leaves during their lifetime, and secrete honeydew. Armored scale form hard, shell-like covers that can be removed from their body. They typically do not move to leaves, and do not produce honeydew. The scales in this stage are all immobile females.

Immature scale are soft bodied, mobile, and called crawlers. They search for a suitable feeding site, and then secrete a protective shell. They are active in the crawler stage.