Nest Architecture, Nest Site Preferences and Distribution of Plebeia wittmanni (Moure & Camargo, 1989) in Rio Grande do Sul, Brazil (Apidae: Meliponinae)

The new species of stingless bees, Plebeia wittmanni, was found during a four years survey of the bees of Rio Grande do Sul, Southern Brazil. Bees of this species construct their nests in cavities of rocks. As the brood nest is not surrounded by an involucrum, the nest architecture can easily be disintegrated and parts of the nest can be built wherever space is available in a crack. Apparently cracks and crevices in granite rocks provide preferable nesting sites. The distribution of P. wittmanni in Rio Grande do Sul suggests that its dispersal is closely related to the occurrence of appropriate rocks, especially granite. In other areas this species was observed as culture follower, nesting in cracks in walls.