LOWER PERFORMANCE IN HONEYBEE COLONIES OF UNIFORM PATERNITY

During mating flights honeybee queens copulate with about 10-20 drones. A possible explanation why polyandry has evolved in honey bees is that colonies from single-mated queens are inferior to those from polyandrous queens. It was investigated whether the performance of full and small test colonies would be lower if workers were from queens artificially inseminated with semen from one drone opposed to equal amounts of mixed semen from several drones. Six colonies with queens inseminated with 1 mul semen of a single drone, each of a different father colony, were compared with six colonies where queens had been inseminated with mixed semen of six drones from the same colonies. Colonies with single paternity showed at times lower drone brood production, lower pollen and honey storage, and fewer queen cells, while deviations in the opposite direction were small and not significant. Bee numbers and amount of sealed worker brood were not affected. Three short-time tests were performed involving a total of 75 small bee colonies kept in Kirchhainer mating boxes. Comb building, storage of honey and pollen, and brood rearing were lower in the colonies containing workers of only one patriline. The results support that a group advantage exists in performance of honeybee workers with mixed paternity, which might have promoted the evolution of polyandry in honeybee queens.