Contributions to a revision of the Hylaeus brevicornis group (Hymenoptera, Anthophila, Colletidae)

The Hylaeus brevicornis group of the subgenus Dentigera is defined and revised. A total of 22 species are included in the group, their circumscription and identification using morphological characters is described and discussed, and their distribution is studied. Three species from Lebanon and Nepal are described as new to science. The hitherto unknown females of Hylaeus (Dentigera) alievi Dathe & Proshchalykin, 2021 and Hylaeus (Dentigera) biarmicus (Warncke, 1992) are described for the first time. An integrative revision of the group involving gene sequencing is being prepared.