Trickling Acid

Most of a hive's Varroa mite population, well 85% of them, usually live within the developing brood leaving only 15% of the population on the adult bees. When there's no brood all the mites should be on the adult bee population and this makes them vulnerable to treatments applied directly to the bees. The treatment I'll be using is a solution of Oxalic acid and sugar syrup.

For the past six weeks or so the night time temperature over here has mainly been below 5 degree Celsius with a some nights of temperatures below freezing. This should mean that by now the queens have stopped laying eggs and the last of the brood should have hatched by now. With hopefully no brood in the comb the mites should all be rather vulnerable. Obviously if there are brood in the hive then the mites will be safely ensconced in the comb and the acid won't affect them.

Off to work we go

Today was a balmy 9 degrees C, armed with a smoker, hive tool a couple of syringes and a bowl of oxalic acid solution I'd warmed in a water bath I went to meet the bees. They were making the most of the slightly warmer weather and whilst I had expected them to be making cleansing flights but I also noticed they were  bringing in pollen from somewhere too.

Are you ready for your treatment?

Including the space between the end frames and the follower boards there's 12 seams per hive. Hive3 with it's caught swarm had about 4 seams worth of bees and was unsurprisingly the weakest colony. They were also the most edgy with a lot of bees flying out to meet me and inspecting the syringe. Hive1 had eight seams and Hive2 was packed with 12 seams of bees. The guidelines are based on a National brood box and suggest 5ml of solution is dribbled down each seam of bees. As I use a commercial which is a little bigger I did a little guesswork and used about 6-7ml per seam. It's a simple enough procedure, you just open the hive and run a syringe along each seam gently squeezing out the solution as you go. Once completed the hives are closed up and you're done.

Seams of bees