Abstract
Sex ratios in slave-making ants have been posed as important test cases for the hypothesis that eusociality evolved via kin selection in insects. Trivers and Hare proposed that sex ratios in slave-makers should reflect the queen's interests whereas sex ratios in free-living host ants should reflect the workers' interests. We analyse patterns of allocation to males versus females, as well as allocation to growth versus reproduction for slave-making ants in the tribe Formicoxenini. We find little support for the hypothesis of exclusive queen control; instead, our results implicate queen–worker conflict in slave-making ants, both over male allocation ratios and over allocation to growth versus reproduction.