The species of this family are very small, aphid-like, often wingless and without caudal siphons. Phylloxeridae are related to the Aphididae and Adelgidae and belong to the superfamily of Phylloxeroidea.
Nymphs and adults feed by sucking fluid from the phloem of plants. Many form leaf galls and feed inside the galls. The most important pest species is the grape phylloxera (Daktulosphaira vitifoliae). It also forms leaf galls, but causes most of the damage when it attacks grapevine roots as part of its life cycle.
The following genera and species are currently entered under Phylloxeridae: