Body is black with a red collar and red on the rear of the thorax. Wings are black with conspicuous white postmedian lines, which are wider in females. Triangular white spots on the wings range from large to almost absent. Females lay eggs beginning at dusk on the same day. Eggs are deposited in clumps on both surfaces of host plant leaves.
Young caterpillars feed gregariously and older caterpillars are solitary feeders.
The cocoon is attached to a twig by a short silken loop and is usually spun near the ground and often in shade. Thorn scrub, foothills and canyons of desert mountain ranges, and dry desert. G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery. A field guide to the moths of eastern North America. Ferguson, D. C. in Dominick, R. B. et al. 1972.