In that same link in post 19 there is this:
"Right away I contacted Zachary to ask him if anything is known about how this works and whether it is wise for beekeepers to continue lowering hive humidity in the winter. I was really worried about this because hive moisture is my favorite “bad guy.”
He responded that 1) nothing is known about how high humidity affects Varroa reproduction and 2) it is still good to control hive humidity in winter for other reasons. And since there isn’t much brood being raised at that time, the effect on mite reproduction is probably minimal."
If this is true, then Zachary appears to not support this concept. I'm confused......
Oh, and just for the record, the relative AM humidity in Norfolk, VA for May through Nov is:
78, 79, 82, 84, 84, 83, 79