CONTROL OF REPRODUCTION IN SOCIAL INSECT COLONIES - INDIVIDUAL AND COLLECTIVE RELATEDNESS PREFERENCES IN THE PAPER WASP, POLISTES ANNULARIS

Social insect colonies often have one or a few queens. How these queen s maintain their reproductive monopoly, when other colony members coul d gain by sharing in the reproduction, is not generally known. DNA mic rosatellite genotyping is used to determine reproductive interests of various classes of colony members in the paper wasp, Polistes annulari s. The relatedness estimates show that the best outcome for most indiv iduals is to be the reproductive egg-layer. For workers, this depends on the sex of offspring: they should prefer to lay their own male eggs , but are indifferent if the queen lays the female eggs. The next-best choice is usually to support the current queen. As a rule, subordinat es and workers should prefer the current queen to reproduce over other candidates (though subordinates have no strong preference for the que en over other subordinates, and workers may prefer other workers as a source of male eggs). This result supports the theory that reproductiv e monopoly stems from the collective preferences of non-reproductives, who suppress each other in favor of the queen. However, we reject the general hypothesis of collective worker control in this species becau se its predictions about who should succeed after the death of the pre sent queen are not upheld. The first successor is a subordinate foundr ess even though workers should generally prefer a worker successor. If all foundresses have died, an older worker succeeds as queen, in spit e of a collective worker preference for a young worker. The results su pport the previous suggestion that age serves as a conventional cue se rving to reduce conflict over queen succession.