Female is larger than the male.
Male abdomen is black with the rear half red, female abdomen is black.
Upperside of forewing of both sexes is black with a band of white spots and a white streak along the costa near the base. Male hindwing is usually solid black and the female hindwing normally has some white spots, although these characteristics are variable. May. Young caterpillars feed in groups on buds and flowers in the mornings, usually resting among branches during the afternoons. Development is rapid, and caterpillars spin cocoons in leaf litter in May or June. Most of these will emerge as adults in the fall, but some may delay emergence for up to 4 years.