||elm leaf beetle
||It appears in midsummer and feeds gregariously. Groups of them defoliate one branch at a time eating all but the mid-vein of each oak leaf.
||European pine sawfly
||Colonies can cause serious defoliation on red, Scotch, and mugo pine.
||The adult locust leafminer is a small yellow and black beetle.
||Yellow or brown tips on arborvitae indicate the presence.
||The large flimsy nests of the fall webworm are a familiar sight along road sides in later summer. The nests grow larger and larger until entire branches are covered.
||eastern tent caterpillar
||Eggs are laid in distinctive shiny masses which encircle small twigs. The caterpillars hatch just as leaves begin unfolding in the spring.
||A coat of long, soft, white hairs identifies this member of the summer defoliator group. Clusters of them feed on the leaves of walnut, butternut, hickory, and pecan.