Sunday, 12 January 2020

Oxalic Acid Demonstration at the District Apiary

On Saturday 11/01/20 following a talk at the monthly meeting about the varroa mite we offered members to join us at the District Apiary to see a demonstration on the application of Oxalic Acid.

The Oxalic acid is readily available at Thornes and can either be 'trickled' into the hive using a solution of crystals in water (always check your labels for mixing instructions and doses) and sugar syrup or can be administered using a vaporizer (again, check instructions on how to use the vaporizer and what quantity to use.

It was a very blustery Saturday morning when we met but the air was dry and a little chilly (though colder would have been better) so we headed over to start the demonstration. We had quite a good turn out for the demonstration and although you can find info and videos on the internet about the procedure I personally like to see things first hand and be able to ask questions whist things are going on and this is the opportunity we wanted to give our members.

We demonstrated both the trickle and vaporiser method and talked through how each can be carried out...necessity of timings, health and safety procedure which should be followed, protective clothes (i.e. mask/goggles/full face masks) and which type of mask to purchase.
We then discussed  the importance of following instructions for mixing and weighing and the reasons why you may want to treat your hives.
Stewart Talking bout timings of burning
the oxalic acid crystals before starting
the procedure

  1. Add 2 grams per brood box, no matter the brood box size, of Oxalic Acid crystals to the head (pan) of your Oxalic Acid Vaporizer. You can use a ½ of a teaspoon (which is the equivalent of 2 grams) as a measuring tool.  For a nuc box, you would use 1 gram.
  2. Insert the vaporizer about ½ to ¾ of the way into hive from the front entrance.
  3. Seal any openings with cloths or foam.
  4. Don your respirator.
  5. Connect your vaporizer to the power source (12 volts) for two and a half minutes (Maximum three minutes – depends on battery capacity.)
  6. Disconnect power source.
  7. Wait 2-3 minutes and remove the vaporizer to prepare for the next hive.
Mask goes on...and timer started as
battery is attached!!

There are 4 hives at the district apiary and we treated two with vapour. One wooden hive and one Polystyrene hive. It is always important to wear suitable protective clothing when carrying out any procedure as there is generally a little seepage of vapour. It was very interesting though that during the treatment of the polystyrene hive there was zero percent of vapour leakage which did then spark up a discussion as to whether or not the poly hive fitted together better due to its materials not shrinking/swelling with weather conditions.

Opening up the top of the first hive to
demonstrate the 'trickle' method.
 As you can see the bees are quite lively...honestly I was relieved to see them so lively after the long wet spells we have had but this wasn't the best for trickling the oxalic acid...none the less....explanations were given and the demonstration went ahead. The temperature was about 7 degrees...ideally you would want to do this procedure at about 4 degrees so that the bees are still in a tight cluster and don't start flying.

The oxalic acid crystals for the trickle technique come
with a handy bottle which measure exactly the right
amount for each 'seam' of bees.
How do you prepare oxalic acid dribble?
Prepare solution
  1. Measure 600 ml of hot water into a non-reactive container.
  2. Add 35 grams of oxalic dihydrate crystals (wood bleach) into the hot water. Stir but do not shake.
  3. When the crystals are dissolved, add the 600 grams of sugar. Stir until dissolved.
  4. When cool use the included bottle to treat your hives so that you get the quantities correct.

Administering the oxalic acid. 

The last seam to be 'trickled' In all
the procedure takes about 30
to 40 seconds.

Oxalic acid is toxic!

  • The lethal dose for humans is reported to be between 15 and 30 g. It causes kidney failure due to precipitation of solid calcium oxalate.
  • Clean up spills of powder or solution immediately.
  • Take care not to inhale the powder.
  • Store in a clearly labelled container out of reach of children.
  • Wear gloves.
  • Do not use containers or utensils you use for food preparation. A carefully rinsed plastic milk bottle, very clearly labelled, is a good way to store the solution prior to use.
If anyone wants to treat their hives by either of these methods and needs any further help, advise or pointers then feel free to contact us.


Unknown said...

Excellent, thank you for sharing your treatments. I use eye protectors (goggles not glasses) as well as a respirator when vaporising. Maybe a thought to consider too?

Tanya. said...

A good point and one that we did cover as we went over health and safety procedure before carrying out the demonstration..however we found that with this type of facemask goggles didn't 'fit' tight to protect the eyes and Stewart chose to go with the mask as opposed to goggles.
We did cover the fact that full face masks can be purchased.

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keep it clean...keep it relevant...I look forward to reading your comments!!