What do beek's use in Finland to keep mites under control.
It "mite" be interesting to try powdered sugar on just one of your hives to see if even better control might be possible. It cant hurt anything. And, if you are like beek' in the USA ...we seem to be a very experimental bunch......we seem to like to think out of the box, "box" pun intended.
If you do try it on jusy one of your hives, I would like to hear how many mites you find.