Bees have been dealing with one problem after another for thousands of years and they are still here. When man interferes by adding chemicals and antibiotics, the bees do not develope the genetics to over come the problem and the problems (pick one, wax moth, SHB, Varroa, AFB, EFB) develop immunity from the things we throw at them. A lot of beeks say you have to treat for varroa or you will loose your hives over the winter. Back in the 1900', the wax moth was wiping out most of the hives. Today nobody treats for wax moths other than protecting stored drawn frames. Why is that? The bees have the genetics to protect the hives from the wax moth and they have learned to constantly remove them. I have read numerous times that you have to treat for varroa by very experienced beeks. This year I collected bees from feral stocks and with no treatment they have all survived the winter and are building up beautifully. 4 years ago, I could not find a bee on my farm if either I or the commercial beeks did not have the hives there. This past year when I did not have bees there nor any commercial bees, I would regularly see them collecting grass pollen in the mornings. Given a chance, the survivor bees figure it out and learn how to handle every thing we throw at them.