Bay Checkerspot

The Bay Checkerspot, Euphydryas editha bayensis, is a butterfly endemic to the San Francisco Bay region of the U.S. state of California. It is a federally threatened species, as a subspecies of Euphydryas editha.

Since the 1980s the population of checkerspots, the Euphydryas species and subspecies, has been in serious decline. Because this particular subspecies is so well studied, the decline was quickly recognized, which led relatively quickly to its federally threatened status designation in 1987.
Recently, two authors have advocated a reclassification for this subspecies of the checkerspot common to western North America, Euphydryas editha. The classification, to Euphydryas editha editha, is for reasons of historical precedence; however, this has not been accepted by the scientific community.