I did a sugar shake today and the mite count in the three colonies was, 1,0,0, respectively.
I had the State of Wisconsin apiary inspector tell me to do this before doing a full blown Apiguard treatment:
Take a piece of butcher paper and cut it to the size of the inside of the bottom board and rub it with vegetable oil and place it the hive (the mites will stick to it but the bees can still walk on it). Then take a tin of Apiguard and leave it in it's normal place and wait 24 hours. If I see more than 15 mites, then I can justify doing a full treatment.
This sounds sensible to me. Has anyone ever tried this? I think Thymol is the lesser of two or more evils in killing the mites. The apiairist said that they did not certify Coumaphos (CheckMite) in Wisconsin because is simply doesn't work very well anymore, at least around here.