Erynnides Burns, 1964

Zhang, Jing, Cong, Qian, Shen, Jinhui, Opler, Paul A. & Grishin, Nick V., 2019, Changes to North American butterfly names, The Taxonomic Report of the International Lepidoptera Survey 8 (2), pp. 1-12 : 6

Erynnides Burns, 1964 is a subgenus of Gesta Evans, 1953 and not of Erynnis Schrank, 1801 , new placement

Gesta Evans, 1953 (type species Thanaos gesta Herrich-Schäffer, 1863 ) is a sister to subgenus Erynnides Burns, 1964 (type species Nisoniades propertius Scudder & Burgess, 1870 ), with the exclusion of subgenus Erynnis Schrank, 1801 (type species Papilio tages Linnaeus , 1758, represented by Erynnis brizo (Boisduval & Le Conte, [1837]) and Erynnis icelus (Scudder & Burgess, 1870) in the US), thus rendering Erynnis paraphyletic ( Fig. 8 ). There are three possible solutions. First (splitting), treat all three ( Erynnis , Gesta , and Erynnides ) as valid genera. However, genetic divergence between Gesta , and Erynnides is moderate (about 8% in the COI barcode), and no prominent tree branches separate the two taxa. Their genitalia are also quite similar. Therefore, these two taxa are best viewed as subgenera. Second (lumping), treat all three as subgenera of Erynnis , thus eliminating genus-species combinations involving Gesta . However, genetic divergence between Erynnis (sensu stricto) and Gesta + Erynnides is prominent ( Fig. 8 ), comparable to that between other Erynnini Brues & F. Carpenter, 1932 genera. While the lumping solution is more compatible with how these taxa were viewed historically, it is not consistent with how other members of Erynnini are partitioned into genera. Third (middle ground), is a two-genus solution, i.e., to transfer Erynnides from Erynnis to Gesta . Phylogenetic trees show the two prominent clades corresponding to these two genera, and the clade leading to their common ancestor is shorter and thus less prominent ( Fig. 8 ). Genetic divergence between these two genera is the same magnitude as between other sister genera of Erynnini. This divergence is equally profound in nuclear (autosomes and Z chromosome) and mitochondrial genomes. Therefore, we prefer this two-genus solution. As a result, all species formerly placed in the subgenus Erynnides of Erynnis would change their genus name to Gesta . This action results in many name changes, but highlights deep genetic divergence between mostly Old Worth Erynnis and exclusively New World Gesta and thus seems to be more biologically meaningful. Although the switch of names is bothersome in short run, it may be beneficial long term.

Figures

Fig. 8. Erynnis and Gesta.