EFFECTS OF WORKER GENOTYPIC DIVERSITY ON HONEY-BEE COLONY DEVELOPMENTAND BEHAVIOR (APIS-MELLIFERA L)

There have been numerous reports of genetic influences on division of labor in honey bee colonies, but the effects of worker genotypic diver sity on colony behavior are unclear. We analyzed the effects of worker genotypic diversity on the phenotypes of honey bee colonies during a critical phase of colony development, the ''nest initiation'' phase. F ive groups of colonies were studied (n = 5-11 per group); four groups had relatively low genotypic diversity compared to the fifth group. Co lonies were derived from queens that were instrumentally inseminated w ith the semen of four different drones according to one of the followi ng mating schemes: group A, 4 A-source drones; group B, 4 B-source dro nes; group C, 4 C-source drones; group D, 4 D-source drones; and group E, 1 drone of each of the A-D drone sources. There were significant d ifferences between colonies in groups A-D for 8 out of 19 colony trait s. Because the queens in all of these colonies were super sisters, the observed differences between groups were primarily a consequence of d ifferences in worker genotypes. There were very few differences (2 out of 19 traits) between colonies with high worker genotypic diversity ( group E) and those with low diversity (groups A-D combined). This is b ecause colonies with greater diversity tended to have phenotypes that were average relative to colonies with low genotypic diversity. We hyp othesize that the averaging effect of genotypic variability on colony phenotypes may have selective advantages, making colonies less likely to ''fail'' because of inappropriate colony responses to changing envi ronmental conditions.