Bay checkerspot butterfly

Bay checkerspot Euphydryas editha bayensis
Conservation status
Threatened (ESA)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Nymphalidae
Genus:	Euphydryas
Species:	E. editha
Subspecies:	E. e. bayensis
Trinomial name
Euphydryas editha bayensis (Sternitsky, 1937)

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. This particular subspecies had been the subject of extensive study by researchers at Stanford University since the 1960s. Thus its vulnerability, particularly in light of rapid land development taking place in the San Francisco Bay Area, was recognized by this group of researchers. Consequently, in 1980 they petitioned the U.S. government to list this checkerspot subspecies as endangered. This led to a prolonged and contentious review by the U.S. Fish and Wildlife Service involving scientists representing arguments for and others against listing and numerous public hearings. The service finally conferred federally threatened status designation in 1987.^[1]

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;^[2] however, this has not been accepted by the scientific community.