We investigated how the evolution of host resistance could affect the infesting population of Varroa mites. We screened a Varroa-resistant honey bee population near Toulouse, France, for a Varroa resistance trait: the inhibition of Varroa's reproduction in drone pupae. We then genotyped Varroa which had co-infested a cell using microsatellites. Across all resistant honey bee colonies, Varroa's reproductive success was significantly higher in co-infested cells but the distribution of Varroa between singly and multiply infested cells was not different from random. While there was a trend for increased reproductive success when Varroa of differing haplotypes co-infested a cell, this was not significant. This dataset may be useful to anybody interested in the evolution of host-resistance on the parasitic mite Varroa destructor. There were no legal or ethical considerations associated with this study.