Eggs overwinter. Self-fertile females hatch in late spring and produce live young. Immatures reach the reproductive stage in 6 to 11 days, giving birth to live young until temperatures cool in the fall, although reproduction continues in warmer areas. Under crowded conditions from late spring through fall, winged females disperse to start new colonies. Adults and nymphs congregate on common St. Johnswort stems, root collars, leaf axils, flowers, and leaves. The onset of cool, short days in northern regions initiates the production of males and egg-producing females. Each female produces four eggs on average, depositing them onto basal winter foliage. There are multiple overlapping generations per year.