Do Melipona bicolor (Apidae, Meliponinae) workers distinguish relatedness among different physogastric queens?

The prediction that the polygynous stingless bee Melipona bicolor workers should distinguish physogastric queens to whom they have different degrees of relatedness was tested. One colony with two physogastric queens was monitored for 5 consecutive days for the occurrence of the provision and oviposition processes (POP) of individually marked workers. We recorded cell provisioning, egg laying, and cell sealing. The presence of one or both of the queens during each POP was recorded. After that, one of the queens from the colony used in the first experiment was removed from the colony and substituted by two other non-related physogastric queens, from other colonies. In both cases preferences by workers towards their mother or aunt or to the unrelated queens were not detected. In a third experiment we demonstrated that guard bees at entrance of a colony do not reject a physogastric foreign queen. Evolutionary and husbandry implications are discussed. © Inra/DIB/AGIB/Elsevier, Pari