Additionally, I hear a lot of people talk about not treating for Varroa mites after using this or that stock for an extended period. That's fine as long as the decision not to treat is based on solid sampling regimes and an IPM approach to the problem. Currently, no stock or line of bees is completely resistant to Varroa -- so relying on any resistance mechanism without proper sampling is folly. I hear it all of the time. I don't treat because I use resistant stock -- three years later the beekeeper could suffer huge losses. All treatment decisions, with or without a resistant stock, should be based on sampling for threshold pest levels. I hope this is the case for your situation.