Precise assessment of the number of patrilines and of genetic relatedness in honeybee colonies

Abstract

Sociobiologists have long sought to estimate precisely the relatedness among members of social insect colonies because of the central significance of kinship in evolutionary and behavioural studies. By using microsatellites, we directly identified the 7-20 subfamilies (patrilines) present in five honeybee colonies belonging to three different subspecies (Apis mellifera mellifera, A. m. carnica and A. m. ligustica). By focusing further investigations on one A. m. mellifera colony, we showed that the genetic structure remained largely unchanged over time as long as the colony is headed by the same queen. The genetic diversity within the colony also provided a good estimate of the genetic diversity of the local honeybee population. The distribution of patrilines was significantly different in swarming workers compared with contemporaneous pupae of the original colony, probably due to unequal propensities for swarming among patrilines. Conversely, no bias in the relative proportions between worker and queen brood could be detected.