Due to the extended egg-laying period, nymphs and adults are present throughout summer. Feeding continues until frost kills nymphs and forces adults into hibernation. There are 3-4 generations each year. The first instar is green with rose-colored legs, antennae, and head. These appendages darken in a few hours.
Subsequent instars are grayish-white with dark heads, legs, and antennae.
The last two instars have noticeable wing pads. The adult bug is dark brown, mottled with light gray on its back side and mottled yellow on its underside. About 16 mm long, it is flat across its back and gives off a disagreeable odor when crushed. Home Garden Insect Control .