At last we have had a few really cold days, but they’re over now. I hope that queens may have stopped laying for a while so as to make an application of oxalic acid syrup solution more effective as it doesn’t act against Varroa in sealed cells.
I ran out of syrup last year. I find that, if kept in the fridge, there is no sign of the brown discolouration indicating the presence of undesirable HMF. It was time to make some more. First find the recipe on Dave Cushman’s web site: 1 part by weight of oxalic acid dihydrate crystals to 10 parts by weight of sugar and 10 of water.
Next work out how much to make. I have 12 hives of my own to treat but friends and apprentices may wish me to treat theirs also so I reckoned on 25 to be on the safe side. I guesstimate an average of 5 seams of bees per hive requiring 5cc of the solution dribbled on them. That makes 625cc. As a follower of the New Zealand KISS (Keep It Simple, Stupid) system I simplified the sums by working on 50 grammes of oxalic crystals and 500 grammes each of sugar and water.
Then to make it. About a decade ago Ben Harden gave me a couple of coffee jars of oxalic crystals at Gormanston and I have already opened the second jar. I found it in a rarely opened cupboard. I found a quart plastic milk bottle, flushed it clean and removed the label, then used a funnel and the kitchen scales to pour in the sugar, followed by the water. I used rain water as having less impurities than the chemically treated hard water coming from the tap. Then I zeroed the scale and added 50 grammes of oxalic, amounting to several teaspoons. A good shake got all dissolved.
Then I found a red marker pen and labelled the bottle POISON! Oxalic acid 3.2% I hope this will prevent accidents as it will sit in the fridge until needed.