Scuticeratina: A new subgenus of small carpenter bees (Hymenoptera, Apidae, Xylocopinae) from Indomalaya

Small carpenter bees (Ceratina) are a morphologically diverse group of bees with a cosmopolitan distribution. The ~ 370 species of this group have been further classified in 25 different recognized subgenera. Here, a distinct new subgenus from Indomalaya, Scuticeratina subgen. nov., with two new species, Ceratina ferruginea sp. nov. and Ceratina phukhaensis sp. nov., are described.

Two described species of previously uncertain subgeneric status, C. muscatella Nurse, 1902 stat. rev. and C. splendida Shiokawa, 2008 stat. rev. are also included within Scuticeratina. The monophyly of this group is supported by both morphological characters and molecular data, including phylogenetic analyses based on targeted genes and ultraconserved elements. Additionally, a third new species is tentatively placed in the nominate subgenus Ceratina Latreille, 1802, C. sirikitae sp. nov., distinct from other known species of this subgenus with unusual red abdominal coloration.

Finally, an updated key to the Ceratina subgenera of the eastern hemisphere incorporating the new subgenus is provided.