Pearl Crescent

Phyciodes tharos — the pearl crescent — is one of about 40 species in genus Phyciodes (the crescent butterflies — a North American-endemic genus) and one of the most familiar small brushfoot butterflies in eastern North America. The species is widespread across all of eastern and central North America from southern Canada south through the eastern US to Mexico. Adults are 3-4 cm wingspan with bright orange-and-black wings (uppersides) marked by intricate dark borders and a pattern of small black spots and bars across the wings; the underside of the hindwing has the species' diagnostic PALE 'PEARL CRESCENT' MARKING — a small crescent-or-comma-shaped pale spot near the wing margin that is the most reliable field-ID feature for distinguishing pearl crescents from closely-related Phyciodes species (northern crescent Phyciodes cocyta, tawny crescent Phyciodes batesii, etc.). The pearl crescent is one of the most-encountered backyard butterflies in eastern NA gardens — common at flowerbeds, woodland edges, and meadows from spring through autumn (the species is multivoltine, with 2-3 generations per year in the southern US and 1-2 generations in northern NA). Adults are nectar feeders on a wide range of flowers but are particularly attracted to ASTERS (Asteraceae composites — the pearl crescent's larval host plant family). Larvae feed exclusively on plants in family Asteraceae — primarily on asters (Symphyotrichum spp.) and related composite wildflowers. Larvae are gregarious in early instars (clustering together on host plants in groups of dozens of caterpillars) and become solitary in later instars before pupating. Pupae overwinter in the leaf litter and the next generation of adults emerges in spring. The species' identifying biology — small size, orange-and-black wing pattern, asters as host plant, pearl-crescent underside marking — is featured in essentially every NA butterfly identification guide. The species is harmless to humans and a major beneficial pollinator of NA wildflowers. The genus Phyciodes is one of the most-studied NA butterfly genera in modern phylogeographic research because the closely-related crescent species often hybridize and have complex geographic-and-altitudinal speciation patterns.