Date of listing: January, 1997
Federal Status: Endangered
The Quino checkerspot is the second subspecies of the widespread butterfly Euphydryas edita to be listed under the Endangered Species Act (The Bay Checkerspot, E. e. bayensis, being the other). This subspecies has undergone a relatively rapid decline. In previous years it has been considered an abundant and fairly widespread subspecies occurring widely in coastal sage scrub habitat in southern California and northern Baja California. However, its range is now limited to a few populations in Riverside and San Diego Counties.
The Quino Checkerspot is a medium sized butterfly with a wingspread of about 3 cm. The wings are a patchwork of brown, red and yellow spots. The Quino checkerspot tends to be darker and redder than other subspecies. Its biology is similar to that of the Bay checkerspot. Adults emerge in the early to mid-spring, mate and lay eggs. The eggs hatch about a week and a half later and the larvae begin feeding. The larvae may use either Plantago erecta or Castilleja exserta, both of which may be common in meadows and upland sage scrub/chapparal habitat. These plants are annuals which die back in the summer and the larvae thus have a period of summer diapause (physiological inactivity) during which they do not feed. In the late winter and early spring as the plants appear again, the larvae commence feeding again and then enter a short pupal (chrysalis) phase.
The main factor responsible for the butterfly's disappearance is clearly development. Much of the historic sage-scrub habitat has been built over. In areas where the habitat persists there are severe threats posed by grazing and the invasion of exotic plants. There are presently approximately 8 populations of the Quino Checkerspot known, at least one of which occurs in Baja California. All but three are extremely small and are thus at risk of extinction due to natural fluctuations. Of these three, two occur in areas already scheduled for housing development. There are presently plans in place for the management of only a single population, in Riverside County, where its distribution overlaps with that of the endangered Stephen's Kangaroo Rat. However, whether one population can ensure the persistence of the Quino checkerspot is highly debatable.
