Carterocephalus skada (W. H. Edwards, 1870)

Zhang, 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), pp. 1-41 : 30-31

Carterocephalus skada (W. H. Edwards, 1870) are species-level taxa and not subspecies of Carterocephalus palaemon (Pallas, 1771)

First, barcode difference of palaemon vs. mandan is the same as palaemon vs. skada : 1.5% (10 bp). Second, mandan barcodes are not much different from skada (0.3%, 2 bp), which can be explained by introgression, but the mandan neotype and magnus holotype exhibit larger difference of 0.76% (5 bp) between them. Third, for comparison, two widely sympatric Old World species C. palaemon and Carterocephalus silvicola (Meigen, 1829) exhibit Fst/Gmin of 0.72/0.0006 (indicating very strong isolation), but barcode difference between them is only 0.6% (4 bp). A number of similar instances of distinct butterfly species not strongly different in their barcodes have been documented ( Burns et al. 2008; Cong et al. 2017), thus barcode differences and similarities cannot be considered separately from all other evidence. In summary, we suggest to reinstate Carterocephalus mandan (W. H. Edwards, 1863) and Carterocephalus skada (W. H. Edwards, 1870) as species, and additionally propose the following revised combinations: Carterocephalus mandan mesapano (Scudder, 1868) and Carterocephalus skada magnus Mattoon & Tilden, 1998 .