Although Northern Crescent (Phyciodes cocyta) and Pearl Crescent (Phyciodes tharos) have been known as separate species since their respective descriptions at the time of American independence from Britain, it has only been in the last three decades that the taxonomy of the cocyta-tharos crescents has come into focus. Until relatively recently, it was assumed that crescents in Maryland were uniformly Pearl Crescents. Distinguishing tharos from cocyta is a very difficult proposition in the field or from photos, requiring close examination of the scaleless underside of the male antennal club tip which in cocyta is bright orange. Proper viewing of this diagnostic characteristic is almost impossible from photographs and requires the specimen to be examined in hand; females are identified by association and habitat. The subspecies in Maryland is Phyciodes cocyta selenis, a (probably) biivoltine large crescent that flies from mid-May to mid-June and again in late summer (flight times have not yet been established conclusively in MD), effectively between broods of the more common Pearl Crescent. Pearl Crescent is a butterfly of fields and weedy areas, much drier habitat than the favored habitat for Northern, which is wet meadows, streamsides, and damp, grassy woods margins. In Maryland it has been reported from Frederick (Harry Pavulaan, pers. comm.) and Allegany Counties. Northern Crescent is likely more widespread in the damp habitats it favors, but suffers from confusion with Pearl Crescent. The female averages a third again larger than female tharos, approaching in some cases the size of Harris's Checkerspot. There are likely to be other crescent species and subspecies to be teased out of the Maryland cocyta-group crescent complex.
Compare with more common and widespread Pearl Crescent.
Uses various asters as larval hosts.
There are 4 records in the project database.
GA | AL | WA | FR | CL | MO | HO | BA | BC | HA | CE | PG | AA | CV | CH | SM | KE | QA | CN | TA | DO | WI | SO | WO |