Dozens of species attack shade trees, shrubs, and herbaceous plants. Most other common species on trees and shrubs overwinter as tiny round eggs on leaves or bark. These eggs hatch in March or April. Both larvae and nymphs resemble the adults. Development time from egg to adult varies from five to 21 days depending on the species of mite and the weather.
Many generations occur each year.
Under optimal conditions, populations can build up very rapidly. Spider mites on conifers and broadleaved evergreens are cool weather pests. They feed heavily and reproduce quickly in spring and fall. Activity is low during the hot part of summer, although damage is often at a maximum and becomes easier to see when other plants are green and growing normally. Spider mites on honeylocust, linden, elm, willow, and oak are destructive in the summer.