The bumblebees of the subgenus Subterraneobombus: integrating evidence from morphology and DNA barcodes (Hymenoptera, Apidae, Bombus)

Abstract

Although bumblebees have received a lot of attention, some taxonomic problems have persisted for many years. One particularly obdurate case has been the species of the subgenus Subterraneobombus. We revise the bees of this subgenus by integrating evidence from both morphology and, for a 5% subsample, from DNA (cytochrome c oxidase subunit 1, CO1) barcodes from pinned museum specimens. We apply a reciprocal illumination procedure: (1) taxa recognized previously from morphology are used to stratify samples for DNA subsampling; (2) DNA barcodes from these subsamples are used to recognize groups of phylogenetically related specimens; and (3) for these groups, we re-examine morphological characters in order to recognize and diagnose species. A total of 3854 specimens from 1535 samples from across the geographic range of the subgenus throughout the Holarctic and northern Oriental regions are identified to 11 species. This includes one species newly recognized from Mongolia, Bombus mongolensis Williams sp. nov. Taxon concepts are modified substantially for four species, seven lectotypes are designated, and four new synonyms are recognized. The prevailing usage of Bombus distinguendus is maintained as valid by designating Bombus elegans as a nomen oblitum and designating B. distinguendus as a nomen protectum. Identification keys and colour-pattern diagrams are provided, and geographic distributions, elevational ranges, and phenological activity periods are described to characterize the species. An estimate of the biogeographic history is reconstructed with dispersal-vicariance analysis. In this study, DNA barcode data have been a cost-effective source of additional characters for diagnosing groups of specimens. The barcode data contributed directly to recognizing the one new species, of which females remain difficult to identify from morphology alone.

Bombus cullumanus—an extinct European bumblebee species?

“…Such a strong distinction (corresponding to the much criticised 'barcoding gap') is not universal among bumblebees (e.g. Williams et al 2011) but is nonetheless apparent in this case. Nonetheless, it would be desirable to compare our COI results for these bees with results from a highly variable nuclear gene.…”

“…Those most likely to confound our analysis are that patterns of evolution for mitochondrial genes do not always correspond precisely with those of their owner species. However, these problems have not yet been detected in studies of bumblebees (Bertsch 2010;Williams et al 2011).…”

Climatic Risk and Distribution Atlas of European Bumblebees

“…However several regional keys or keys specific to some subgenera are available (Pittioni, 1938;Løken, 1973Løken, , 1984Alford, 1975;Rasmont & Adamski, 1995;Amiet, 1996;Ornosa & Ortiz-Sánchez, 2004;Edwards & Jenner, 2009;Intoppa et al, 2009;Williams et al, 2011Prys-Jones & Corbet, 2011). Bombus alpinus (L., 1758)…”

Subspecific differentiation in male reproductive traits and virgin queen preferences, in Bombus terrestris

“…Moreover, bumblebee species have been affected by biogeographic events (Williams et al 2011;Duennes et al 2012;Lecocq et al 2013a;2013b). These features of bumblebees could lead to intraspecific spatial genetic differentiation (Avise 2000) as well as to spatially varying selection regimes within species (Wright 1951) and, consequently, to evolutionary divergences (Williams 1991;Estoup et al 1996).…”