A primary insight into the molecular phylogeny of Colias FABRICIUS, 1807 (Pieridae, Coliadinae) complex of South America

TL;DR

This study uses mitochondrial DNA barcoding to analyze the molecular phylogeny of South American Colias butterflies, revealing their monophyly, species distinctions, and evolutionary relationships within the genus.

Contribution

It provides the first comprehensive molecular phylogeny of South American Colias, clarifies species boundaries, and proposes a subgeneric classification within Colias.

Findings

South American Colias form a monophyletic clade.

Identified three well-established species and a complex of emerging species.

Found that South American Colias are largely divergent subcomplexes of the genus.

Abstract

The data on molecular phylogeny of the Colias complex of South America (SA), obtained via barcoding a mitochondrial part of genome, are reported. Barcoding was trialed employing the Barcoding of Life Database platform and comprised 93 specimens of SA Colias sp. plus 2 outgroup specimens (C. philodice guatemalena from North America). It is established that Colias sp. from SA form a single monophyletic clade, characterized by notable interspecific mutational divergences (3.5-4.5%) and moderate intraspecific ones (0.3-0.9%). It also reveals the occurrence of 3 well-established (notably diverged genetically) species (C. dimera, C. vauthierii, and C. alticola, the latter re-raised to sp. level), plus a complex of 3 'emerging' species (C. lesbia, C. euxanthe, and C. flaveola) which are weakly differentiated genetically. Furthermore, it disregards the sp. status of taxa weberbaueri, mossi, nigerrima, erika, blameyi, and mendozina, as certain evidences are being brought to consider them ssp. of a clinal type of super-sp. C. flaveola s. lat. Importantly, the clade formed by SA Colias is found to be sister to the one comprising Colias sp. occurring outside the region (in Eurasia, North America, and Africa). A direct comparison of the results obtained for SA Colias with those for worldwide Colias (GenBank data) leads to the conclusion that these are largely divergent autochtonous subcomplexes, being in fact subgenera s. lat. of genus Colias. The first subgenus comprising all SA Colias sp. and named Aucolias (Austral Colias, or of southern hemisphere stem) is sister to the second one (comprising all Colias sp. from the Old and New Worlds), for which the name Colias (Colias) s. str. is preserved.