Dominance interactions regulate worker mating in the polygynous ponerine ant Gnamptogenys menadensis

In queenless ants, workers compete aggressively to be reproductives instead of sterile helpers. To limit the number of reproductives, either mating or egg-laying by mated workers can be regulated. In Gnamptogenys menadensis, all mated workers reproduce, and field data presented here indicate that ma ting is not random. We removed gamergates experimentally (n = 16 groups) to induce mating and gamergate replacement. Virgin workers engaged in agonist ic interactions, allowing us to classify them into two groups: dominants pe rformed antennal boxing and biting, while subordinates did not. However, a few subordinates cooperated to immobilize individual dominant workers. This effectively reduced the number of dominants because immobilized dominants became subordinates. Six to 12 wks after the removal of reproductives, betw een one and eight dominants per colony started to perform 'sexual calling' outside the nest entrance. Sixteen tout of 33) dominants mated with foreign males introduced in five experimental groups. None of the subordinate work ers mated. The probability of mating is thus regulated by dominance interac tions among workers and immobilizations initiated by infertile workers in t his polygynous queenless ant.