They excrete honeydew, Severe infestations may stunt plant development and cause premature leaf drop and small flowers. Sooty molds may also develop on the honeydew. May. These hatch and crawlers move to the leaves where they feed until late summer. The nymphs molt into the second instar which moves back to the twigs to spend the winter. They hibernate under a thin, waxy shield.
Males usually pupate and emerge in early spring.
Some lecanium scales can lay fertile eggs without mating. As adult females mature, they become rounded and hardened. As the eggs are laid, the body of the scale shrinks against the outer skin to form a protective shield over the eggs. These scales are not easily eradicated. Evidently, the scales on the twigs are protected from pesticides by the thin waxy covering or the adult scales are not susceptible to pesticides.