The genus Colias Fabricius, 1807 is a taxonomically challenging group of butterflies.
Many Colias taxa display a high level of intraspecific variation in wing pattern and are weakly
differentiated with respect to genitalia structure; therefore, a conclusion on their status as a distinct
species, subspecies or local form can be controversial. In such cases, it is crucial to conduct a
comprehensive analysis based on various phylogenetic and biogeographical approaches and a largescale
sampling dataset in order to resolve existing taxonomic and nomenclatural problems. In the
present study, we focused on two enigmatic Colias taxa of unclear taxonomic status, Colias mongola
Alphéraky, 1897 and Colias tamerlana Staudinger, 1897, restricted in distribution to western Mongolia,
northwestern China and the south Siberian part of Russia. Here, we conducted a DNA barcode-based
analysis that revealed complicate genetic pattern with several differentiated haplotypes clustered in
four distinct haplogroups. In addition, we found a strong correlation between a specific mitochondrial
haplogroup and Wolbachia infection, suggesting that Wolbachia endosymbionts may have played an
essential role in the biology and diversification of the taxa in question and the genus Colias as a whole.