|California dogface butterfly
Colias eurydice Boisduval, 1855
First state insect 
The California dogface butterfly has been the state insect of the U.S. state of California since 1972. Its endemic range is limited to the state. California was the first state to choose a state insect — and thus, to choose a butterfly — though most of the other states have now followed, and many even have both a state insect and state butterfly.
The 'dogface' name comes from a wing pattern resembling a dog's face (some think it looks like a poodle) which is found on the male of the species. Its wings are an iridescent bluish-black, orange and sulfur-yellow in color. The female has a small black dot on each of its yellow forewings. The typical forewing length is between 22 to 31 mm. See picture (main page) — unfortunately lacking the dog-pattern.
Food and habitat 
Larvae feed on Amorpha californica, false indigo.
Adults feed on flower nectar. They are said to be especially fond of purple flowers.
In the California chaparral and woodlands habitats of the Santa Ana Mountains in Southern California, the adult California Dogface butterflies can often be seen nectaring at roadside thistles: such as the native Cirsium hydrophilum and Cirsium occidentale, and introduced invasive species Cirsium arvense.
They are hard to get close to, are hard to catch unless nectaring at flowers, and are hard to get a photograph of with their wings open because they fly very fast.
See also 
- List of Lepidoptera that feed on Cirsium - thistles