A 2020 genomic study by Jing Zhang, Qian Cong, Jinhui Shen, Paul A. Opler, and Nick V. Grishin sequenced the genomes of the holotype and paratypes and found pronounced genetic differentiation from P. catullus, with statistics indicating very limited gene exchange and reproductive isolation between the two. On this basis they elevated crestar to species rank, reversing its earlier synonymization with P. catullus in Jonathan P. Pelham's catalogue. The same study found that one original paratype, from Mono County, was genetically P. catullus rather than P. crestar.
Etymology
The name crestar refers to the "starry" row of small white dots on the hindwing, resembling stars in a crescent across the dark wing surface.
Description
Pholisora crestar closely resembles P. catullus but nearly all individuals show a submarginal row of tiny white spots on the dorsal hindwing, usually with smaller spots on the forewing as well; these are reduced or absent below. In P. catullus generally, only about a third or fewer of individuals show any trace of this spotting.
Distribution
The species is centered on the southern Sierra Nevada of Kern and Tulare counties, California. Populations east of the Sierra crest, in the Owens Valley and adjacent Mono County, show weaker or absent spotting and intergrade with P. catullus; genomic data confirmed at least one Mono County specimen to be P. catullus. Similarly spotted individuals have also been noted from southern California, though not yet confirmed as P. crestar.
123456789Scott, James A.; Davenport, Ken E. (2017). "Weeds can also be stars: A new subspecies of Pholisora catullus (Hesperiidae)". Papilio. New Series (26): 2–4.
12345Zhang, Jing; Cong, Qian; Shen, Jinhui; Opler, Paul A.; Grishin, Nick V. (2020). "Genomic evidence suggests further changes of butterfly names". The Taxonomic Report of the International Lepidoptera Survey. 8 (7): 1–40.
