Phylogenetic Relationships of the Bumblebee Subgenus Pyrobombus (Hymenoptera: Apidae) Inferred from Mitochondrial Cytochrome B and Cytochrome Oxidase I Sequences

Abstract

Traditionally, the genus Bombus (Apidae: Apinae: Bombini) is divided into several subgenera. This study derives an approximation of the relationships between 10 species of the subgenus Pyrobombus (from both Europe and North America), B. lapidarius L. and B. sichelii Radoszkowski from the subgenus Melanobombus, and B. terrestris L. from the subgenus Bombus s. str., by comparing the mitochondrial cytochrome b and cytochrome oxidase I (COI) genes. Although bootstrap values for deep branches are mostly low, the sequences show significant phylogenetic signal, low homoplasy, and all trees share some patterns that are consistent with those from other phylogenetic studies on bumblebees. These results show that the subgeneric names Pyrobombus and Melanobombus do not accurately reflect phylogeny, and therefore it would seem wise to revise the existing system into monophyletic species-groups or even ignore the subgeneric names altogether.