One point that has not been made is that the honeybee as host for varroa is an evolving relationship. If it we not for us humans re-introducing the honeybee, the habitat for the varroa would have been decimated and the mite would not persist. This of course at the expense of the honeybee and the beekeepers. At this point varroa is too efficient to its own good! I would expect that the population dynamics of varroa in various regions will fluctuate wildly from year to year due to the fact that varroa ends up killing the host hive, thus destoying its habitat. Not a highly evolve dynamic. ?Does anyone know what the mite population dynamics have been in Europe from year to year within regions? From an avolutionary point of view, varroa in conjunction with the honeybee would eventually evolve a relationship that would permit both to survive or not. In the surviving relationship the host would not be killed. As beekeepers we are getting into the mix. Time will tell if we can contribute effectively to the process from the honeybee's perspective. At this point we started and magnified the problem! Jim Moore