Interesting point Finman. Swarms often replace dead colonies without anyone knowing the difference. The small cell proponents claim that feral bees, because of the natural small cell comb they build, reach equilibrium with the mites. Study reveals that in nature, bees build lots of different sized comb, so I'm not sure small cell is truly the answer. Maybe a combination of natural sized comb, hygenic, mixed with defensive behaviour. Maybe it's all natural selection, and what's left in nature is truly resistant stock?
I was recently invited to remove a wild colony that had been in place for at least 4 years. A racoon ripped the top off and destroyed the colony before I had a chance to get them. Very dissappointing. The bees that I found appeared very dark, and very small. hmmmmm. I wonder what that indicated?