West Coast lady it lacks obvious ventral eyespots on the hindwings; there are two large ones on "V. virginiensis" and four small ones on "V. cardui". Like the latter, it also lacks a white dot in the pinkish-orange subapical field of the ventral and dorsal forewings. Its upperwing coloration has the purest orange of the three; the American painted lady is usually quite reddish. A less reliable indicator is the row of black eyespots on the dorsal submarginal hindwing. These are usually of roughly equal size in "V. cardui" and lack blue centers, though the summer morph may have a few tiny ones.
Urophora cardui Urophora cardui Urophora cardui or the Canada thistle gall fly is a fruit fly which, contrary to its common name, is indigenous to Central Europe from the United Kingdom east to near the Crimea, and from Sweden south to the Mediterranean. The Canada thistle gall fly has been introduced to North America from Europe to control the population of its host plant, Canada, or creeping thistle, which is an invasive, introduced weed in North America. The fly starts life as an egg, about one to thirty of them, laid on the stems of its host plant, the Canada thistle, "Cirsium