The genus <i>Speyeria</i> and the <i>Speyeria atlantis</i>/<i>Speyeria hesperis</i> complex: Species and subspecies accounts, systematics, and biogeography (Lepidoptera: Nymphalidae)
Speyeria Scudder (1872) (Nymphalidae: Heliconiinae: Argynnini) are medium to large butterflies that represent conspicuous members of North American Lepidoptera. Speyeria is presently comprised of 16 species, and according to some authors, over 100 subspecies. Long included in the Old World genus Argynnis, they differ from their Eurasian relatives primarily in genitalic structure and were considered generically distinct from Argynnis in 1945. Varying degrees of isolation via geographical and glacial histories, dispersal and occasional contact of disjunct populations likely provide developmental processes that produce gradients, thresholds, and wing pattern changes in Speyeria . The Speyeria atlantis and Speyeria hesperis species complexes are represented by several widely distributed, geographically variable subspecies. These subspecific taxa have distributions that range from the eastern United States and Canada, west to California, as far north as Alaska, and south to Arizona and New Mexico. Each subspecies occurs more or less sympatrically, either by latitude or elevation, with other members of the group, thus providing useful models for evolutionary studies.
Detailed species and subspecies diagnoses for 16 Speyeria species and 25 Speyeria atlantis-hesperis subspecies are compiled. Each diagnosis includes a synonymy, type specimen data and image, taxonomic information and morphological descriptions, distributions, and life history information. Distributional data is gleaned from museum and private collection locality records and databased in order to understand the degree of sympatry of Speyeria atlantis and S. hesperis forms. Several errors in the nomenclature, type specimen data, and morphological descriptions for Speyeria are also identified.
Phylogenetic analyses are also conducted on the 16 currently recognized species of Speyeria. Investigation of useful external and internal morphological characters was made, including a survey of the genitalia of Speyeria with emphasis on the Speyeria atlantis-hesperis complex. Phylogenetic analyses are based on combined morphological, life history, and genetic data. The genus apparently represents a relatively recent radiation of species, with the only clear divergence being those members of the Semnopsyche ‘clade.’ Based on combined morphological and molecular analyses, Speyeria represent a monophyletic grouping. This work provides relevant insight into the inter- and intraspecific relationships and evolutionary history of Speyeria, and provides information pertinent to conservation strategies and priorities for this taxon.