Cephalic secretions of the bumblebee subgenus Sibiricobombus Vogt suggest Bombus niveatus Kriechbaumer and Bombus vorticosus Gerstaecker are conspecific (Hymenoptera, Apidae, Bombus)

Three taxa of the subgenus Sibiricobombus live in the Near-East mountain steppes: Bombus niveatus, B. sulfureus and B. vorticosus. The latter is also present in the Balkan. B. niveatus and B. vorticosus can only be distinguished based on color pattern. B. sulfureus differs in coat color and in genitalia. We identified 40 compounds in the secretions of the labial glands of these taxa, among which 7 were detected for the first time in labial cephalic gland secretions of bumblebee males. Whereas the secretions of the male cephalic labial glands of B. sulfureus are very different from those of B. niveatus and B. vorticosus, we found no significant difference between the latter. We conclude that B. sulfureus is a valid species, whereas B. vorticosus is a mere subspecies of B. niveatus: Bombus niveatus ssp. vorticosus Gerstaecker nov. status.