Re: queens and broodless periods - tell me about this please!
Both bees, and mites, can extend their life quite a bit during a winter broodless period. Where I live, there is brood all year, but where I used to work in a colder part of my country there was a winter broodless period of at least couple months. As to how that effects mites, a mites life span seems more determined by how many reproductive cycles it has had, possibly connected to the amount of sperm it gets in it's only mating at the beginning of it's life.
So in a broodless period, the mites just keep living until there is brood again. In my own experiments with this using bees with little / no varroa resistance, mite numbers after a 6 week broodless period were almost identical to numbers at the start of the broodless period. However anecdotal evidence on Beesource is that if the bees have a degree of mite resistance in the form of grooming or attacking adult mites, a broodless period will reduce mite numbers because the mites are not hidden in the brood they are out among the bees and vulnerable to attack.
So it would seem likely that the success of a broodless period as it will affect mite numbers depends on your bees.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).