Both sexes move about for longer periods of time than the armored scales. Some move out onto the leaves as crawlers and in the fall move back onto the twigs before leaf fall. Eventually, they settle down to feed, mate, and lay eggs. The sooty mold fungus grows upon this honeydew, blackening the foliage, twigs, and bark. Soft scales generally have one generation per year.
Soft scales infest many deciduous woody plants and some conifers.
Elms, maples, and fruit trees are commonly infested. The crawler stage may be dispersed by wind and water as well as migrating birds, small mammals, larger insects, etc. Scale insects have piercing and sucking mouthparts. They reduce the vigor of their hosts by sucking plant juices. Bark and sapwood tissues injured by scale feeding gradually turn brown and die.