Overwintering 6-frame Nucs
Bees do not smell - they have chemical receptors for specific compounds. They don't have noses as we do, so it's unlikely that other smells can mask the important ones.What if bees use their sence of smell to locate mites and groom each other? Most functions in a hive are controlled by smell. Anyone seeing queen supersedes when they are not needed? Maybe they just can't smell their queen like they should.
So if we assume for a minute, that in the gene poll we have hives that are mite resistant and die because the smell function is disabled, and hives that are not mite resistant, but are able to smell(due to less exposure to a man made chemical) the mites and remove some and live. Over time, you will loose your good genes because the loss of smell from a human chemical is masking the mite issue.