Effective paternity in natural colonies of Japanese native bumble bees

Kin selection theory predicts a high coefficient of genetic relatedness among nestmates, explaining the frequent evolution of eusociality in a social hymenopteran colony. The bumble bee is a primitively eusocial hymenoptera whose colonies are founded by a single queen. In such a monogynous colony, mating frequency of the queen is the sole factor that affects genetic relatedness among nestmates. Although the queens of most bumble bee species are known to be monandrous, there are some species that are known to be polyandrous. Here, we estimated the effective paternity in the native colonies of Japanese bumble bees, Bombus ardens, B. diversus, and B. honshuensis, using genetic polymorphic data of microsatellites. We found no evidence for polyandry in any investigated colonies, which suggests that within-colony genetic relatedness is very high for all of these colonies.