Michael Palmer wrote: > > Why? I would think that Varroa would have a hard, if not impossible > time becoming resistant to the acidity of OA. > Mike > I would never say impossible since you are dealing with a bug that reproduces quickly, so you can have many generations over a short period. So things can happen that allow resistance (tolerance) so the separation between the dose that kills the mite is closer to the dose that harms the bee.At that point, treatments would be counter-productive. (But the bee may also be more tolerant, so it could be a moving target. Who knows?) Even humans can develop a tolerance for many poisons, like arsenic. My guess is that it, if it does happen (and I tend to agree with Mike, that it will not), will take longer than the ten years for Apistan. We shall see it first in Europe, so they will let us know. Bill Truesdell Bath, Maine -- Visit www.honeybeeworld.com/bee-l for rules, FAQ and other info ---