I applied oxalic acid to both hives today.
Oxalic acid helps in the fight against varroa, and after my high mite-counts I am keen to do everything I can. It's a short-lived treatment that only kills mites that are living on the bees and does not kill mites that are in the brood. That's why it's done at this time of year when the colony is broodless. If brood were present, around 85% of the varroa would be in with the brood. Oxalic acid is thought to have a kill efficiency of over 90% on those darn mites. It's cheap to buy, and comes as a liquid in a small bottle with one of those 5ml measuring devices attached. (Hhhhmmm - I've just been watching a video online where some guy was not drizzling a solution over the bees to give the oxalic acid treatment, but instead vapourising crystals into the hive - clearly there's more than one way to skin a cat.)
On removing the crown boards, the stuporous bees were initially too sluggish to even acknowledge my presence. However, when I drizzled 5ml of oxalic acid along between each pair of frames a few took notice and started checking me out. Although it was about 8degrees celcius I was anxious not to encourage too many out in case they did not make it back, so I worked as quickly as I could and each hive was done in a minute.
So that really is goodbye from me to the bees for the winter. I'm not sure what happens now - I suppose I'll check them out again on some warm day in March. Best that I read a book I think - I've got the Ted Hooper one to enjoy over Christmas when I'm in New Zealand for a monster 4 week holiday. I leave later today....I can't wait!