Kin recognition and inbreeding reluctance in bumblebees

Inbreeding frequently has a costly impact on fitness, thus selection has favoured the evolution of kin recognition and inbreeding avoidance behaviour in many species. As haplodiploid Hymenoptera, bumblebees are susceptible to additional costs of inbreeding due to their single-locus complementary sex determination (sl-CSD) system, which means that incest can result in the production of costly diploid males. Here we test whether Bombus terrestris reproductives are able to discriminate between kin and non-kin and whether their willingness to mate is adjusted accordingly. We found that B. terrestris reproductives took significantly longer to mate with siblings compared to non-relatives. This indicates that this species exhibits kin recognition and uses this information to determine mating behaviour. © INRA/DIB-AGIB/ EDP Sciences, 2009.