Dione incarnata N. Riley, 1926

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 : 24-25

Dione incarnata N. Riley, 1926 is a species distinct from Dione vanillae (Linnaeus, 1758)

Heliconius charitonia (Linnaeus, 1767) and H. erato (Linnaeus, 1758) (Fig. 19). In contrast to their separation from Dione vanillae insularis ( Maynard, 1889) (type locality Bahamas, Fig. 19 blue), the name currently applied to Jamaican populations, the two USA subspecies: eastern Dione vanillae nigrior ( Michener, 1942) (type locality USA: Florida, Monroe Co.) and western Dione vanillae incarnata N. Riley, 1926 (type locality Mexico: Durango), cluster closely with each other (Fig. 19 red). The Fst/Gmin statistics for the two groups (red vs. blue) are 0.81/0.0002, indicating nearly absent gene exchange between these groups, the smallest of all sister species we studied in this work. Search of the BOLD database ( Ratnasingham and Hebert 2007) reveals that Jamaican specimens group closely by their COI barcodes with specimens from other Caribbean Islands ( Cuba, Dominican Republic, Puerto Rico), and in particular with specimens from the Bahamas (the type locality of D. v. insularis . Therefore, Jamaican populations may indeed be referred to as D. v. insularis . The COI barcode differences between Jamaican insularis and USA incarnata is 2.9% (19 bp). For these reasons, D. vanillae insularis is apparently a species distinct from the USA species consisting of subspecies nigrior and incarnata .

These two species ( insularis and the USA species) are distinct phenotypically with wing shapes and patterns, as described by Maynard (1889). In fact, Maynard proposed Agraulis insularis as a species, and he considered the USA species to be Agraulis vanillae , characterized by longer wings, smaller black spots, white dots in forewing black spots compared to insularis . However, both the Merian illustration (1705), which was mentioned in the original description of D. vanillae (Linnaeus, 1758) , and the lectotype specimen ( Honey and Scoble 2001) reveal the insularis phenotype (e.g. extended black band on the forewing, broader wings) that differs from the USA specimens. In his revision, Michener gave a key to the vanillae complex taxa ( Michener 1942). The first doublet separates incarnata with nigrior from all other taxa, including the nominotypical vanillae . Therefore, the USA specimens are not D. vanillae , but a species that may be referred to by the oldest name applicable to North American populations: D. incarnata , and we currently leave insularis as a subspecies of D. vanillae . Michener also raised the possibility that incarnata may be a distinct species, based on incarnata specimen from Colombia, in which case it would be sympatric with D. vanillae . However, these Colombian specimen might have been mislabeled. Due to the evidence presented here, Dione incarnata N. Riley, 1926 , new status, appears to be a distinct species, with D. incarnata nigrior ( Michener, 1942) , new combination, being its subspecies.