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Oxalic acid in a sugar solution is dribbled between the frames over the bees as a varroa miticide when the brood is at its least, i.e. after a long cold spell. Whilst it can kill the mites on the bees or in open brood cells it can’t touch those behind a brood cell capping. A writer in BBKA News claimed that brood frames could be removed even in mid-winter, any cappings perforated and then the frames replaced prior to the oxalic acid treatment.

We hadn’t had a long cold spell but it’s a matter of compromise so I chose a day to suit me best. It was a lovely day; 9°C and the sun was shining. Thank goodness I was in full armour. Whilst it was too cold for the bees to be flying naturally, they really went for it, and me; when I took the decision to break the cluster out of their hands and made the decision for them. Having started however, I decided to press on and found three small patches of brood on two frames which I duly perforated with my uncapping fork before re-assembling the hive.

Lesson learned, the other seven hives were just given a quick 5ml of oxalic acid between the frames and the crown-boards replaced.

Unbeknown to me however, my back and hat had collected a huge number of hangers-on; the disadvantage of being a solo beekeeper. Having completed the work, as I disrobed and pulled my jacket over my head the bees on the back decided that my now bare face was a good target for revenge. Oh well, I suppose it helps to build up sting resistance early in the season.

One job leads to another they say.

I’ve discovered that my smoker needs some serious reconditioning as the hinge is worn and badly distorted and the interior is really caked up; a workshop job for a wet day.

No netting has been needed so far this year as there’s been no permafrost..

Stuart Roweth, inventor of note (and the Beegym) has sent me the mite-drop statistics for some of his hives through 1918. Some hives had two and even three Beegyms both above and below the frames and the results were really impressive. Rather than having just one gym on the floor of several hives I’ll try putting several in a few hives, above and below the brood and see what the figures are like.

The winter honeysuckle has flowered extremely well this year and the bees have been making good use of it on the many flying days.

Once the feeding is all done and the feeders removed, beekeeping becomes a more relaxed pastime. In effect, there is little to be done apart from the oxalic acid varroa treatment and repairs to equipment.

Oxalic acid will achieve an approximate 95% knock down of varroa. Not a complete cure but sufficient to seriously deplete their numbers before the brood rearing starts in earnest.

I mix a 50:50 solution of sugar water and add 18.75g of oxalic acid dihydrate to the mix. This is then dribbled 5ml into each between-frame seam of bees. Having the crown board up on matchsticks makes its removal almost vibration free.

The acid will only kill the mites which are outside the brood cells and cannot touch any beneath a wax capping. It is best therefore to do the treatment after a seriously cold spell which will have reduced the queen’s laying to almost nil. i.e. less sealed brood and hidden varroa.

Charging needle-less hypodermic

Trickling oxalic acid between the frames

 

 

 

 

Each colony can be done in less than a minute and the hive quickly closed up again before the cluster suffers heat loss.

The varroa trays go underneath just to give me an indication of efficacy.

This treatment can only be done once a year as the acid burns the carapace (the dorsal exoskeleton) of the bee and must also burn the bee’s mandibles.

In the workshop I have reinforced the bellows on the stainless-steel smoker, repainted the numbers on the hive roofs and made a new aluminium cover for roof 8.