Emergency queens inTetragonula carbonaria(Smith, 1854) (Hymenoptera: Apidae: Meliponini)

Abstract

There is increasing interest in the management of stingless bees for crop pollination, honey production and recreational beekeeping. Colony propagation is based on the division of one colony into two smaller colonies. The process generates a queenless colony and requires that the new colony is successful in the production of a new queen. Three different mechanisms by which female larvae develop as queens have been described for stingless bees: (1) genetic determinism with no differentiation in the cells used for rearing queens and workers; (2) queen development is determined by large queen cells; and (3) queen cells are formed by the fusion of two worker-sized brood cells. Colonies of species that utilise specially constructed queen cells cannot be divided artificially unless there are queen cells present at the time of splitting. Here, we show that queenless colonies of the Australian stingless bee Tetragonula carbonaria (Smith, 1854) can construct queen cells by the fusion of two worker-sized cells. This phenomenon is unknown from any other stingless bee species with a spiral brood comb. It has the practical benefit that beekeepers can divide hives even when there are no queen cells present. Finally, it is shown that T. carbonaria workers remain completely sterile in queenless colonies.