Not everyone is treating! I'm sure you'll get more posts like this. Most take the method of survival of their fittest stock and grow from that stock.
The producers of many of these strains and races of bees will tell you that their genetics improve their bees tolerance but that they will still succumb to the parasite's pressure and/or the vectored diseases.VSH bees and the Russian bees and the Survival bee stocks .....why do you have to still treat for varroa?
I believe that members of the Russian queen breeders assn agree not to treat. Having said that, I still think they say you should monitor and treat your bees as needed.However, not all breeders breed survivors, and they themselves treat.