Younger larvae are brick-brown with yellow stripes along the body. Older larvae are black with yellow stripes and up to two inches long. Late season defoliation does not significantly harm tree health, but can be unsightly. After spending the winter as pupae, adults emerge in June and July and lay egg masses on leaf undersides. These eggs hatch in late July into caterpillars that feed in groups through August.
Large caterpillars pupate in the soil where they spend the winter.
Look for young caterpillars in July and treat before caterpillars become large and cause major damage. Though late season defoliation is unsightly, it does minimal harm to tree health because it occurs close to the time of normal leaf drop. Cicada killer wasps are large, yellow and black wasps that evoke a good deal of fear among people. They may fly about people, hover in front of their heads, or even appear to dive-bomb at them, but this is all in show. In fact, most of the wasps seen are males patrolling a nesting area.