I have been reading the study done in Quebec on SBB and varroa drop. In it they stated that when the screened bottom boards were left open, ie they removed the catch tray, the rates of infestation actually went up over the season.
They explained this as due to a temperature drop within the hive and that the lower temp was more condusive to mite breeding and the so growth in numbers.
I question this finding because
1) the mites reproduce in the brood area exclusively
2) the brood area is amazingly stable in tempurate, regulated by the bees themselves.
So either the bees can't regulate the temperature and the fall in temperature would slow hatching in the brood area.
... or the mites are reproducing outside the brood area which is cooler
... or ???
Does anyone else have an idea what was really going on, or other input ??
"hobby farm" is an oxymoron