These pests hatch from eggs in early spring through mid-May. They move to the leaves of trees for feeding at night, but in heavy infestations, they may feed during the day as well. These caterpillars grow by molting, and their appetite increases after every molt. They feed until the pupal stage occurs in mid-June or early July, and when they emerge as moths, reproduction takes place from July through September. If you see tan or buff-colored hairs on tree trunks, sides of buildings or outdoor furniture, you may have a problem with gypsy moths, but we can help.