Photo courtesy of Leroy Simon. Above, a female Callosamia securifera moth courtesy of Leroy Simon. Both sexes are active during the day, and mating takes place between 1 pm and 3 pm. Male moths are much darker than females, and the summer brood is darker than the spring brood. In the extreme south, females of the spring brood are often yellowish orange.
Females lay eggs at dusk, in short rows on the host plant leaves.
Eggs hatch in about a week, and the young caterpillars are gregarious feeders. Third instar larvae are depicted to the right, courtesy of Leroy Simon. Older caterpillars are solitary feeders, and do not eat the main vein of the leaf. Instead, they cut the leaf petiole at the base and it falls to the ground, perhaps a defensive measure eliminating visual or olfactory signs of feeding. Photo courtesy of Leroy Simon.