Wing span: 2 1/8 - 3 inches (5.4 - 7.6 cm).
Identification: Upperside forewings of both sexes have yellow "dog's head" surrounded by black. "Eye" does not touch black border. Female similar, with duller, more diffuse black areas and 2 seasonal forms: underside hindwing of wet season "summer" form is yellow; that of dry season "winter" form is mottled with black and pink.
Life history: Males patrol open areas for females. Eggs are laid on the undersides of terminal leaves of host plants. Adults overwinter in reproductive arrest.
Flight: Three flights in the southern states from May-June, July-August, and September-April. Northern colonists have one generation per year, or do not reproduce at all.
Caterpillar hosts: Small-leaved plants in the pea family (Fabaceae) including alfalfa (Medicago sativa); prairie clovers (Pentalostemon), indigo (Dalea), and clover (Trifolium) species.
Adult food: Nectar from flowers including alfalfa, coreopsis, houstonia, and verbena.
Habitat: Dry, open areas such as short-grass prairie hills, scrub oak groves, open woodland, washes, road edges.
Range: Resident in South America north to southern Texas and peninsular Florida. Stray or temporary resident from central California northeast through the Great Lakes area and all the eastern states.