Distribution of Varroa destructor between swarms and colonies
Jerzy Wilde, Stefan Fuchs, Janusz Bratkowski and Maciej Siuda
Bee colonies reproduce by colony division during swarming. In colonies infested by the parasitic mite, Varroa destructor, colony division will at the same time split the mite population between the swarms and the remaining parent colonies. The present investigation compares infestation of swarms with that of parent colonies. We found that an average of 25 ± 9% of mites left the colonies with natural swarms, while 75 ± 9% remained in parent colonies of which 39 ± 11% were on bees and 36 ± 10% were within sealed brood cells. The relative swarm infestation did not differ from that of the remaining parent colony in this study, but very low proportions of mites within sealed worker brood and a clear negative correlation to the proportion of mites in sealed brood strongly suggest that swarm infestation is asymmetric and lower than that of the remaining colonies.