Image Credit: Frank D. Lospalluto
Identification: Upper side is bright reddish orange with narrow dark markings. Lacks the prominent black inner marginal spot of Phyciodes pallidus. Underside is yellow-orange with somewhat blurry rusty orange markings.
Wing Span: 1 1/8 - 1 1/2 inches (3 - 3.8 cm).
Caterpillar Hosts: Native thistles (Cirsium), milk thistle (Silybum marianum), and European thistles (Carduus).
Adult Food: Flower nectar.
Habitat: From sea level to 8000 feet in mountains, fields, meadows, roads, vacant lots, parks, and fencerows.
http://www.butterfliesandmoths.org/species/Phyciodes-mylitta