In the spring, the adults become active about the time the leaf buds open. The female lays her eggs on the underside of the developing leaves. Egg hatch occurs in 7 to 10 days and the young nymphs begin to feed immediately. The leaf reacts to the feeding by producing a pouch or gall that entirely encloses the nymph. Nymphs pupate in the fall and adults emerge in September.
Control is very difficult.
Adults that invade homes can be collected by using a vacuum sweeper but the bag should be discarded or the adults will escape. Since these insects do not seriously affect the vitality of the hackberry tree, control is usually not recommended. Life Histories of Common Insects, Mites and Nematodes Infesting Ornamental Plants in Missouri, Missouri Department of Agriculture, Plant Industries Division, pg J-7 2.