Photo by Drees. Hind wings of males are marked with orange. Carpenterworms develop over 1 or more years. Adults begin to emerge in spring.
Females lay masses of eggs on trunks and branches of host plants.
Reddish-pink caterpillars hatching from eggs and tunnel into sapwood. Before mating the greenish-white larva with a dark brown head tunnels into heartwood to pupate. Female leopard moths lay clusters of eggs in bark crevices. Caterpillars hatching from eggs crawl before tunneling into bark. Overwinters as a larva.