Do Worker Honey Bees Discriminate among Unrelated and Related Larval Phenotypes?

Abstract

Experiments were designed to test the hypothesis that worker honey bees can recognize the phenotype of larvae and use this information to favor closely related individuals when rearing queens. Three experimental designs were employed. The first required colonies to rear emergency queen cells; this represents a “natural” context. Queenless bees of one sibling group were given the choice of rearing queens from larvae of the same or a different sibling group. In the second and third experiments larvae were grafted using standard commercial techniques for rearing queens. In one experiment, worker bees could choose between rearing larvae from their own or a different racial group, in the other the choice was between their own and genetically similar larvae. The results of these experiments do not support the original hypothesis; no phenotypic preference in rearing emergency replacement queens or in choosing grafted larvae was noted. We conclude from these experiments that under normal conditions information concerning the phenotype of honey bee larvae does not allow discrimination between related (half- or full-sister) and completely unrelated individuals.