I was watching tv yeaterday and saw something interesting. It dealt with a midge resistant grain. When seeding they also allowed 10% non resistant seed into the mix. The reasoning was that it would allow these midges to eat on that 10% and make it harder for the midges to find a mate that picked up an immunity to the seed.
Would it be of any benefit to allow say 10% of hives to go untreated so that you can keep a gene pool of mites not resistant to miticides? This could be done with the lower production hives (sacrificial lambs).