Exoneura

Exoneura is a genus of small, native Australian bees belonging to the family Apidae, subfamily Xylocopinae, and tribe Allodapini. These bees are typically black or dark brown in color and are known for their subsocial nesting habits.

Exoneura bees are unique among bees due to their progressive provisioning behavior, where the mother bee continues to feed her developing larvae after they hatch. This contrasts with most other bee species that provision a cell with all the food a larva needs before sealing it off. In Exoneura, the mother bee remains with her offspring, providing them with pollen and nectar until they reach adulthood.

They build their nests in pithy stems, twigs, or branches of various plants, hollowing out a chamber in the stem to create a linear series of cells. The mother bee lays her eggs in these cells and tends to her young, regulating temperature and humidity, and protecting them from predators.

Exoneura bees are important pollinators of native Australian flora. Their relatively small size allows them to access flowers with smaller openings than larger bee species.

The social structure within Exoneura nests can vary, and in some species, cooperative breeding occurs, where adult daughters assist their mother in raising subsequent broods. This level of social complexity makes Exoneura a valuable model for studying the evolution of social behavior in bees.

Species within the Exoneura genus are distributed across a wide range of habitats in Australia. Their survival is impacted by habitat loss and fragmentation, as well as the introduction of non-native species.