The cosmopolitan bee genus Ceratina, often referred to as small carpenter bees,Small Carpenter Bee – Ceratina sp. Red Planet Inc. is the sole lineage of the tribe Ceratinini, and is not closely related to the more familiar carpenter bees. The genus presently contains over 300 species in 23 subgenera.DiscoverLife Ceratina They make nests in dead wood, stems, or pith, and while many are solitary, a number are subsocial, with mothers caring for their larvae, and in a few cases where multiple females are found in a single nest, daughters or sisters may form very small, weakly eusocial colonies (where one bee forages and the other remains in the nest and lays eggs). One species is unique for having both social and asocial populations, Ceratina australensis, which exhibits all of the pre-adaptations for successful group living. This species is socially polymorphic with both solitary and social nests collected in sympatry. Social colonies in that species consist of two foundresses, one contributing both foraging and reproductive effort and the second which remains at the nest as a passive guard. Cooperative nesting provides no overt reproductive benefits over solitary nesting in this population, although brood survival tends to be greater in social colonies. Maternal longevity, subsociality and bivoltine nesting phenology in this species favour colony formation, while dispersal habits and offspring longevity may inhibit more frequent social nesting in this and other ceratinines.Rehan, S., Richards, M., & Schwarz, M. (2010). Social polymorphism in the Australian small carpenter bee, Ceratina (Neoceratina) australensis. Insectes Sociaux, 4(57), 403-412.
