The Painted Lady, Vanessa cardui, is the most widely distributed butterfly in the world (Opler and Krizek, 1984; Scott, 1986). It is found throughout Europe, Asia, Africa, North America, and Central America. It is not a permanent resident in the eastern United States, but quasi-periodically migrates there from the deserts of the southwestern U.S. and northern Mexico (Opler and Krizek, 1984). These migrations are sporadic and often enormous, and often follow rainy periods in these deserts. Scott (1986) recognizes two subspecies: V. cardui cardui is found throughout North America south to Venezuela and throughout the Bahamas and Antilles; throughout Eurasia including India and Ceylon, and Africa including Madagascar. The other, V. c. kershawi, occurs in Australia and New Zealand and strays into Fiji. Hawaiian V. cardui adults are intermediate between the two subspecies, and both forms can develop from the eggs of a single female (Scott, 1986). According to Opler and Krizek (1984), V. cardui prefers open areas, including old fields, vacant lots, and gardens. I have found that in Iowa, V. cardui prefers more open areas such as prairies and fields, whereas V. atalanta prefers forest margins and parklike areas with more trees. Painted Lady larvae feed on a wide variety of host plants of the families Compositae (especially thistles), Boraginaceae, Malvaceae (especially the hollyhock Althaea), common mallow (Malva neglecta), and a number of legumes (Opler and Krizek, 1984) including Iowa soybeans (Scott, 1986) The dorsal side of the wings is orange-patterned. On the underside of the hindwing are five small submarginal eyespots. Females are generally larger than males. Male forewing length ranges from 2.5 to 3.3 cm (mean = 3.0 cm); female forewing length ranges from 3.0 to 3.4 cm (mean = 3.2 cm) (Opler and Krizek, 1984). V. cardui, like V. atalanta, has distinct summer and winter forms. The summer form is larger and brighter and has blue pupils in the submarginal spots on the dorsal hind wing (Opler and Krizek, 1984). The winter form has entirely black wing spots. The number of broods in any one place may vary from year to year because it is not a permanent resident in most of the U.S. (Opler and Krizek, 1984).