Purdue University Life history Scales spend most of their lives immobile, with their tubular mouthparts anchored to the plant tissue on which they feed. Eggs hatch beneath females into young mobile scales called crawlers. As it continues to grow, it remains beneath its waxy armor. At each of the three successive molts, it produces a new shell that expands beneath the old armor. This waxy covering is difficult to penetrate with insecticides.
Winged males crawl out from beneath their cover and mate with covered females who produce eggs.
Females can produce about 100 eggs each. Soft scales are not covered by a waxy shell and excrete large amounts of liquid excrement called honeydew. Crawlers hatch from eggs in mid-summer. In most species, crawlers go directly to leaves where spend most of the summer. They return to the twigs and bark where they spend the winter as settled second stage scales.