Tierney et al. (2008) describe the first four nests collected of Xenochlora nigrofemorata, from Madre de Dios, Peru.
Xenochlora bees have metallic green and/or coppery heads and thoraces, light brown abdomens, and black setae on their hind legs. They are distributed throughout the Guyana Shield to the Amazonian basin. They form a monophyletic group with Megalotpa. Like Megalopta, they construct tunnel nests in dry, rotting wood suspended above the ground (as opposed to soil nests, like most sweat bees). However, unlike Megalopta, which is nocturnal, Xenochlora is diurnal.
Nests of X. nigrofemorata were similar to those of Megalopta. A tunnel was excavated into the end of a relatively soft, dry stick, liana, or vine suspended above the ground. Cells were constructed in excavated cavities such that the cell entrances were flush with the tunnel wall, and a entrance collar made of chewed wood particles was constructed to constrict the nest entrance to the width of the bee’s head.
Nests contained from 2 – 6 females, and from 0 – 11 brood cells. New nests of X. nigrofemorata are probably initiated by a solitary foundress. If the queen remains after the brood emerge, and the brood function as workers, then these colonies would be eusocial. If the queen dies but the brood form queen and worker castes, then the colonies would be semi-social. If all females reproduce, they would be communal. The authors present evidence that X. nigrofemorata have semisocial or eusocial colonial organization, but cannot rule out communality based on ovarian dissections that show multiple females can have developed ovaries in the same nest. Like Megalopta, Xenochlora may exhibit a range of social organization.
