I had been planning to treat them this fall after the harvest, but due to some traveling, harvesting and wine making and just plain procrastination, I hadn't done it yet. Although it was threatening to rain soon, I suited up right away and did an application of the miticide Hopguard, which I purchased at the Mann Lake shop earlier this summer when we were in that area fishing. I put two strips on each of 3 brood boxes. I check my pull-out board in the back of the bottom board each time I examine the hives and it was my general feeling that mite populations were not excessive. I see I need to be much more precise in my measurement in the future. There clearly is a problem in at least one of the hives.
I also see that the wax moths are back and active. We found worms, moths and their messy trails on the pull-out tray. I cleaned them out of the bottom of the bottom board structure and plan to check that every few days to make sure they aren't in there building again. Last spring I did see evidence of some worm damage in a frame in the bottom super (a hole chewed all the way through the top of one frame). I may have to investigate some chemical treatment though I'd prefer to just try to physically remove any that I see and add some sticky paper to catch them.
Update: (Oct. 5) We opened the hives yesterday. The sickly sweet odor that the wax moths produce was so strong that we felt, like last year, we needed to go into the hives and take a look around. The odor yesterday was not as strong as it had been the previous several days, and we found no evidence of any moth activity within the hive. We found strong hives, with larva and capped brood. The bees had been working over the strips of Hopguard. I now feel all the detritus on the bottom tray is a result of the bees chewing up the chemical strips rather than wax worms chewing through the frames. I'll keep up monitoring the bottom trays but feel much better now about the worm situation.