Gulf Fritillary Butterfly

The Gulf fritillary is a medium to large butterfly, with a wingspan of 6–9.5 cm (2.4–3.7 in). Its underwings are buff, with large silvery spots.[1] It takes its common name from its migration over the Gulf of Mexico.
The Gulf fritillary is commonly seen in parks and gardens, as well as in open country. Its range extends from Argentina north through Central America, Mexico, and the Caribbean to the southern United States, as far north as the San Francisco Bay Area on the west coast. It is occasional farther north.

http://en.wikipedia.org/wiki/Gulf_fritillary