Wings are white with black markings including a black crescent-shaped cell spot on each wing. Females lay eggs in rings around twigs of host plants. Eggs overwinter and hatch from April-June.
Young caterpillars feed together while older ones feed alone.
Fully-grown caterpillars overwinter in loose cocoons in the leaf litter or in burrows in soft soil. Adults emerge from July-September, but at high elevations and northern latitudes, the cocoons overwinter and adults emerge in the spring. Great Basin sagebrush communities, pinyon-juniper woodland, and subalpine sagebrush meadows. Subspecies marcata is in southern Oregon and northern California, while subspecies magnifica occurs in northeastern Arizona, northern New Mexico, and southern Colorado. G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.