Orphaning does not affect the colony productivity of the primitive eusocial wasp Polistes snelleni

Abstract

In colonies of primitively eusocial wasps, some dominant workers become successive queens and inherit queenship after the death of the foundress queens. Although workers in many species do not mate, workers of Polistes snelleni are capable of mating and female production. In this study, we removed foundress queens from colonies of P. snelleni to evaluate the effects of queen loss on the dominant–subordinate relationships among the remaining workers and the productivity of colonies in the species. The foundress queens were the sole egg layers in almost all of the queenright colonies. The frequency of dominance behaviour among the wasps in the queenright colonies was significantly less than in the orphan colonies. The frequency of dominance behaviour in the successive queens after queen removal was significantly more than in the foundress queens. Multiple workers had developed ovaries, including the successive queens in 66.7 % (10/15) of the orphan colonies after queen removal. The orphan colonies produced significantly more cells and eggs than the queenright colonies. Our results suggest that the reproductive potential of the successive queens in the orphan colonies is not lower than that of the foundress queens, and that the productivity of the orphan colonies is maintained rather than causing potential conflict over direct reproduction among workers.