If you want them "mite resistant" you must "stop treating for mites" in order to allow bees to develope such resistance.
There is much to swallow from all the comments.
What does "stop treatments" mean? What about "Doing nothing"? Not treating with chemicals...what is that? Is it as one person suggested "letting the weak just die"?
I do not treat when someone is talking about mite chemical treatments. But that only goes as far as "not treating" when it comes to applying chemicals. But do I "treat"? Yes. I manage and influence the health of my bees in many ways. And they all would be considered a "treatment".
I influence where they sit (sun versus shade)
I influence what equipment they use (Screened bottom board)
I influence how often they get a new queen (Feral colonies requeen almost EVERY year)
I influence genetics by keeping more bees in some areas that what they would in nature.
I expand, contract, and change the brood chamber to benefit me, effecting the brood cycle and mite production.
I keep bees in weak r-value hives that may need additional management to optimize survival chances.
I effect the bees in how they draw comb.
I keep bees in areas they may not otherwise survive, thrive, select, or prosper.
I do not like when people suggest "No treatments" is little more doing nothing and letting the weak die. I never plan on letting any hives die. I manage my hives and part of my IPM is actively culling out the weak myself, by requeening, combining, etc. Yes, it is easy to manage mite IPM. And much harder to manage viral and other IPM areas.
While I allow mother nature to cull out the weakest in winter, it does mean doing nothing. It means that there are bee issues that I could not control even if I wanted. I think we can select for traits beneficial for regional acclimation, and a hands off approach for these traits is one best taken.
But allowing bees to just die out due to mite issues is for what purpose? I would rather promote the raising of better queens, requeening those hives failing to handle mites, and taking an active role in what continues, what is eliminated, etc.
It's not about just standing back and allowing hives to die.
Do I put chemicals in my hives that do nothing but help perpetuate weak genetics? No. But do I "treat" my bees and take an active approach in IPM to achieve certain goals and allow the bees to survive? You bet.