Finnish beekeepers routinely treat their bees with oxalic acid as a part of their varroa mite management protocol. Most commonly they use the dribble method of inserting oxalic acid  sugar syrup between the frames. That's what I also did a year ago with my Farrar frame hives. Even though it seems  a little strange to open the hives in the middle of the winter and pour syrup right on them they didn't seem to be too bothered about it. The bees will lick the syrup off each other. The reason the treatment is done in the winter is that it is not effective to varroa mites that are in the brood -...