I dust my hives with powdered sugar twice a year (when I remember) and all newly hived swarms before they cap brood. Each hive is lifted off it's base, moved two feet forward and placed on a temporary stand before dusting. I leave it there for 48 hours or so before moving it back onto it's cleaned, and torched, base. My theory is that there will be no significant mite drop after that time.
My question is this: How long can a varroa mite live after it has been groomed off it's host? How far can it travel in this time? Is there any way it could make it back into a hive two feet away? ( Sorry that's three questions) Anybody out there got experience with sugar dusting, combined with drone culling, as "chemical free" varroa management?
May you live long and prosper.