Painted Lady (Vanessa cardui)...
...on Common Milkweed (Asclepias syriaca).
The Painted Lady along with the Cabbage White is one of the most widespread of all butterflies, found on every continent except Antarctica. In Australia it has a limited range, however, its close relative, the Australian Painted Lady (Vanessa kershawi, sometimes considered a subspecies) ranges over half the continent. Other closely related species in North America are the American Painted Lady (Vanessa virginiensis), and the West Coast Lady (Vanessa annabella).
In North America the Painted Lady ranges from the deserts of northern Mexico, where it migrates and temporarily colonizes the United States and Canada south of the Arctic. Occasionally, population explosions in Mexico will cause massive northward migrations, which hasn't been the case the past three years. Quite the opposite.
Adult butterflies prefer nectar from composites 3-6 feet (1-2 meters) high, especially thistles; also aster, cosmos, blazing star, ironweed, and joe-pye weed. Flowers from other families that are visited include red clover, buttonbush, privet, and milkweeds as seen in these photos.
Caterpillar host plants include more than 100; favorites include thistles (Asteraceae), hollyhock and mallow (Malvaceae), and various legumes (Fabaceae).
Habitat is almost everywhere, especially in open or disturbed areas including gardens, old fields, dunes, etc.
ISO400, aperture f/11, exposure .003 seconds (1/350) focal length 300mm