Most larvae crawl back to the tent at night, but forage out to feed during the day, defoliating increasingly larger portions of the branches and tree. The young larvae hatch at or before bud growth in March or April and gather in a fork of the limbs to spin their large webby nests. The larvae leave during the day to feed, but return to the nest at night, or during rainy weather. One generation per year. Overwinter in egg masses on small twigs.
Early control is important.
However, it is difficult because larvae begin feeding on leaves unfolding from the bud before there is adequate leaf surface to be sprayed. Insecticides with residual effectiveness are desirable. Most will kill larvae hit by the spray, however, larvae in webs are protected from sprays. Treat foliage and twigs during the day. Webs can be flash-flamed at night with care not to get bark scorch or burning.