As I understand, the proper use of powdered sugar is to dust the bees, not
"POUR It ON EACH SEAM?? of bees.  I have carefully dusted each frame and
had much larger mite fall than was reported and it along with open screen
boards, drone brood freezing and the use of wintergreen patties has
produced colonies that have survived over two winters without toxic
chemical treatment.  Small sample, non scientific research but my colonies
are alive and well coming out of a terrible dry summer and fall with some
winter stores.
Paul LeRoy    South Carolina, USA