Oxalic Sublimation by Tamsin Harris
by Tamsin Harris
There's not many years when we have low temperatures corresponding with the short days of late December and early January down here in Cornwall.
Unfortunately for the varroa mite, this winter has given the ideal conditions for oxalic acid treatment, with the aim of reducing phoretic mites (those living on the adult bees). Ideally the hive should be in a broodless period in order for the treatment to kill as many of the phoretic mites as possible, but inevitably temperatures are in double figures at this time of year in Cornwall, and queens haven't stopped laying. The mites that are reproducing under the brood cappings won't be killed by the oxalic acid so it's best to choose a time when there is little or no sealed brood.
This year it's different and I'm preparing the kit needed to sublimate Apibioxal.
My protection is essential so I will be wearing a gas, vapour and particle filter mask (makes a change from a COVID face mask) and stout latex rubber gloves with gauntlets.
I'll be using a Varroa Clean sublimator that will need a 12v power supply so my spare car battery has to be charged up, although I don't relish the ideal of lugging that around my out apiaries - maybe I'll use a battery power pack.
This is all planned for this coming weekend to allow as much brood to emerge as possible. The cold weather ideally needs to last for three weeks for all the brood to emerge after the queen has stopped laying due to the low temperatures.
Read next weeks' blog and view the photos to see how I've been getting on fumigating my hives!