When I was keeping all local survivor bees, developed by walk-away splits from an original cut-out colony, they behaved as if they were likely AHB's. I never treated them (over a period of at least eight years) and never lost a colony, though sometimes one part of a walk-away split would simply abscond to parts unknown. They had many other undesirable behaviors, but were very durable and productive.
Now I've taken to importing Cordovan Italian queens, then breeding additional queens from the best of them. They are open mated, so these daughter queens can sometimes build colonies with a few undesirable traits, I screen these out by growing many nucs of these daughter queens and quickly replacing any queens that don't perform as desired.
I have continued to restrain myself from using any typical treatments for mites. The treatments I do use; I spritz a little Certan on combs in storage to reduce damage from wax moth larva, and I also add a little supplemental copper to the syrup I feed nucs while getting them established. Those are the only two treatments I have come to use - otherwise my colonies are without treatments, I have recently had colony losses (the first in all my years of beekeeping), one out of each ten colonies these past two years. In October/November of 2008 I lost most of about a dozen nucs, when they were suddenly usurped by likely AHB queens, then soon afterwards they perished in mysterious circumstances.
I know those queens were usurped because they were all newly mated and laying golden Cordovan Italian queens, then I did a check about two weeks later and I couldn't find a single golden queen in any of these nucs, they were all very dark queens.
