I did some mite testing a week and a half ago and the count just skyrocketed over previous weeks. I recognized that this was not a good situation to go into fall and winter with so I did treat, very reluctantly, with Apiguard, a Thymol-based miticide. I hate being put on the pesticide treadmill and the bees did not like it as well. There is not really much written about the bees initial reaction to thymol use, but, between the 90 degree temperature and the Apiguard, both hives got an extreme case of bearding that scared me a bit.
The temperatures plummetted this week, so the bees are much less active right now. I am observing them closely.