SOCIAL-ORGANIZATION IN EXPERIMENTALLY ASSEMBLED COLONIES OF ROPALIDIA-MARGINATA - COMPARISON OF INTRODUCED AND NATAL WASPS

In the primitively eusocial wasp, Ropalidia marginata worker behaviour cannot be explained satisfactorily by the haplodiploidy hypothesis du e to the existence of polyandry, serial polygyny and movement of wasps between nests, which reduce intra-colony genetic relatedness to level s lower than the value expected between a solitary foundress and her o ffspring. We introduced wasps eclosing from one set of colonies into o ther colonies separated by a distance of 10 km or more, to examine the possibility of kin recognition and task specialization under conditio ns of low intracolony relatedness. Introduced wasps were readily accep ted into unrelated foster colonies, where they performed most of the b ehaviours and tasks shown by the natal wasps. We found no evidence of kin recognition or task specialization among natal and introduced wasp s. Introduced wasps sometimes became replacement queens in spite of th e presence of natal wasps. Taken together with previous observations, these results lend support to the idea that factors other than genetic relatedness must play a prominent role in the evolution of worker beh aviour in Ropalidia marginata.