Re: Varroa mites! Now what?
If you want to stay treatment free then here is a way... Oh shoot, I just noticed where you are at. Winter is close by for you. OK, here's my idea. Shake all the bees into a new box of foundation and keep a syrup feeder on them so they get it drawn and full of stores for winter. Be quick about it if you're going to do this way. It will remove all infecteced combs, break the brood cycle also, but will cause you to try over wintering in a single deep box nuc. Good luck on whatever you choose to do.
20+ years, raise my own queens, feed when needed. I treat, but have not perfected varroa management yet.