Damaged foliage may be wrinkled or purplish, curled or cupped, and stunted. The immature mites are glassy white, or transparent pale green. All stages are slow moving. The hind legs in the female are threadlike, and those of the male are pincerlike. The larva is similar with six legs.
Delphinium is injured from early spring to early summer and again in late summer.
Injury is seldom caused in the high heat of mid- to late summer. Each female deposits about 90 eggs over several weeks, five or six per day. Eighty percent or so are females. The eggs hatch in a week and the larva is active for a week, then molts to the eight-legged nymph. The nymphal stage is a quiescent one of about 3 days before molting to the adult.