TY - JOUR

T1 - The steppe bumblebees of the subgenus Sibiricobombus revised world-wide from species’ gene coalescents and morphology despite numts (Hymenoptera, Apidae, genus Bombus)

AU - Williams, Paul H.

AU - An, Jiandong

AU - Byvaltsev, Alexandr

AU - Ghisbain, Guillaume

AU - DE JONGHE, Roland

AU - Huang, Jiaxing

AU - Mei, Maurizio

AU - Monfared, Alireza

AU - Orr, Michael C.

AU - Raina, Rifat

AU - Streinzer, Martin

N1 - Williams, P. H., An, J., Byvaltsev, A., Ghisbain, G., De Jonghe, R., Huang, J., Mei, M., Monfared, A., Orr, M. C., Raina, R., & Streinzer, M. (2026). The steppe bumblebees of the subgenus Sibiricobombus revised world-wide from species’ gene coalescents and morphology despite numts (Hymenoptera, Apidae, genus Bombus). European Journal of Taxonomy, 1041(1), 1–59. https://doi.org/10.5852/ejt.2026.1041.3199 We thank all of those who have collected specimens (listed for each species), and those who have maintained museum collections, especially J. Monks (NHMUK), F. Bakker and W. van Bohemen (Naturalis), and J. Yao (IZCAS). Thanks to the Canadian Centre for DNA Barcoding at Guelph, Canada, for barcode sequencing and to S. Brace (NHMUK) for the ancient DNA sequencing for B. oberti. Thanks to L. Berridge (NHMUK) for taking the genitalia images. Thanks to the Chinese SAFEA High-End Foreign Experts Recruitment Program (GDJ20140326002, GDJ20150325001, GDJ2016032602) for funding PW’s research in China. Thanks to I. Beavis for advice on the form and meaning of the name tescorum. Thanks to L. Bailey for discussion and to the referees for constructive comments.

PY - 2026/2/19

Y1 - 2026/2/19

N2 - Bumblebees of the subgenus Sibiricobombus Vogt, 1911 of the genus Bombus Latreille, 1802 are associated with dry grasslands in the montane regions of Mongolia, Central Asia, the Qinghai-Tibetan Plateau and surrounding mountains, to as far west as Greece. Many of the taxa in this group were described initially from their colour patterns and have at different times been regarded as separate species or have been put into different combinations that were variously regarded as species. We examine integrated evidence for species as evolutionarily independent lineages, comparing evidence from species’ gene coalescents, based on fast-evolving barcode-like DNA sequences, and from discontinuous variation in skeletal morphology and in colour patterns. Many sequences of Sibiricobombus taxa appear from their AT bias at the third codon position to be recent low-divergence numts. Higher frequencies of these numts may be associated with more substitutions within the barcode-primer-binding regions of the mitogenome since the divergence of bumblebees from the lepidopteran source of the primers. Nonetheless, in this particular case, all but one of the 12 species’ gene coalescents support candidate species that are corroborated by morphological diagnoses. For the 11 corroborated species, the status of three species is revised and one new replacement name is proposed: Bombus sibiricus (Fabricius, 1781), B. semenovi Morawitz, 1887 stat. rev., B. oberti Morawitz, 1883, B. morawitzi Radoszkowski, 1876, B. sulfureus Friese, 1905, B. niveatus Kriechbaumer, 1870, B. obtusus Richards, 1951, B. tescorum Williams nom. nov. et stat. rev., B. longiceps Smith, 1878 stat. rev., B. falsificus Richards, 1930 stat. rev., and B. asiaticus Morawitz, 1875. Nine new synonyms are recognised. Estimates are provided for (1) an evolutionary tree for species and (2) for the ancestral species’ distributions.

AB - Bumblebees of the subgenus Sibiricobombus Vogt, 1911 of the genus Bombus Latreille, 1802 are associated with dry grasslands in the montane regions of Mongolia, Central Asia, the Qinghai-Tibetan Plateau and surrounding mountains, to as far west as Greece. Many of the taxa in this group were described initially from their colour patterns and have at different times been regarded as separate species or have been put into different combinations that were variously regarded as species. We examine integrated evidence for species as evolutionarily independent lineages, comparing evidence from species’ gene coalescents, based on fast-evolving barcode-like DNA sequences, and from discontinuous variation in skeletal morphology and in colour patterns. Many sequences of Sibiricobombus taxa appear from their AT bias at the third codon position to be recent low-divergence numts. Higher frequencies of these numts may be associated with more substitutions within the barcode-primer-binding regions of the mitogenome since the divergence of bumblebees from the lepidopteran source of the primers. Nonetheless, in this particular case, all but one of the 12 species’ gene coalescents support candidate species that are corroborated by morphological diagnoses. For the 11 corroborated species, the status of three species is revised and one new replacement name is proposed: Bombus sibiricus (Fabricius, 1781), B. semenovi Morawitz, 1887 stat. rev., B. oberti Morawitz, 1883, B. morawitzi Radoszkowski, 1876, B. sulfureus Friese, 1905, B. niveatus Kriechbaumer, 1870, B. obtusus Richards, 1951, B. tescorum Williams nom. nov. et stat. rev., B. longiceps Smith, 1878 stat. rev., B. falsificus Richards, 1930 stat. rev., and B. asiaticus Morawitz, 1875. Nine new synonyms are recognised. Estimates are provided for (1) an evolutionary tree for species and (2) for the ancestral species’ distributions.

KW - Barcode

KW - coalescent

KW - distribution

KW - integrative

KW - species

UR - https://www.scopus.com/pages/publications/105030945684

UR - https://www.mendeley.com/catalogue/65cb3bd2-877e-35a2-ae2a-c71090a2e668/

U2 - 10.5852/ejt.2026.1041.3199

DO - 10.5852/ejt.2026.1041.3199

M3 - Article

VL - 1041

SP - 1

EP - 59

JO - European Journal of Taxonomy

JF - European Journal of Taxonomy

SN - 2118-9773

ER -