Adult beetles have characteristic cream and black stripes across the back. Females deposit eggs in clusters on the underside of leaves. The eggs are orange and each mass will contain between 20-45 eggs. CPB larvae are crimson in the early instars with black legs and two rows of black spots on the sides of their body.
Large larvae are orange and appear bloated and humpbacked.
Pupae are located in the soil. The beetle has 2 reproductive generations per growing season in Pennsylvania. The 1st comes from overwintering adults, and the second from in-field reproduction. Overwintering adults emerge in early May, locate a host and begin to feed and mate. As with most insects, all forms of activity and development from one life stage to the next is temperature dependent.