Once mature, the female begins to lay eggs within a gall. Nymphs hatching from these eggs crawl to new leaves at shoot tips, settle on the leaves, and form new galls. In the case of the root form of grape phylloxera, the insects overwinter as immature forms on the roots. These forms mature in the spring and produce eggs that hatch into nymphs. The nymphs then start new galls on the roots.
Winged forms develop in the spring, summer or fall and emerge from the soil to lay eggs on stems.
These eggs hatch and produce the true sexual forms that produce the overwintering eggs laid under the bark. Several generations of each form of phylloxera may occur each season. Although the two forms behave differently, both belong to the same species of phylloxera that occurs on the leaves and roots of grapes. The insect forms galls on the leaves and roots of grapevines. The vine will die if its roots become heavily infested with phylloxera.