This pest prefers heavy, clay soils that are found in the cooler grape-growing regions of the state such as Napa, Sonoma, Lake, Mendocino, and Monterey counties, as well as the Sacramento Delta and the foothills. Although grape phylloxera is present in the heavier soils of the San Joaquin Valley, damage may not be as severe and it is not a pest on sandy soils. They are generally oval shaped but egg layers are pear shaped. Newly deposited eggs are yellow, oval, and about twice as long as wide.
Nymphs resemble adults except they are smaller.
Grape phylloxera overwinter as small nymphs on roots. First instar nymphs are active crawlers and may move from plant to plant in the ground, on the soil surface, or by blowing in the wind. They may also be moved between vineyards on cuttings, boots, or equipment. Once established on a root, phylloxera feed externally in groups. Occasionally, winged phylloxera are seen in V. vinifera vineyards, but they are believed to be sterile under California conditions.