December 7, 2016/January 3, 20176.4°C and 3.6°C

To treat or not to treat. There's no question. (In my mind, anyway.)

People often assume that organic means treatment-free. In fact, the Canadian organic standards allows varroa treatment with formic acid, oxalic acid, and essential oils such as thymol, all of which are considered organic. To treat or not to treat is a subject of some controversy in beekeeping and beekeepers tend to feel strongly one way or the other. Personally, I think the treatment-free advocates raise important and compelling questions. Are we simply promoting a more treatment-resistant varroa? Are the treatments – organic or not – adding to the chemical overload in the hive? Are the outcomes any better with treated hives than those that aren’t treated? The answers could very well be yes, yes and no, but I have to admit that I am not prepared to go there at this point. And the main reason is I can’t stand the thought of my bees walking around with dinner plate-sized parasites eating holes in their bodies. Or losing whole colonies while they build up resistance. As well, there is increasing evidence that the viruses that accompany varroa can be transmitted to wild bees, and organic beekeeping is all about respect for the environment, not just our own bees. And so I treat.

Having said that, I am committed to using the least invasive method and frequency of treatment, which I believe is oxalic acid vapor applied twice in the winter. There are some good reasons for this, starting with current research, which shows high efficacy and low impact on bees, my two main criteria. I also appreciate that I don’t have to open the hive, because by the time the brood has hatched it’s early winter in my area and my hives are wrapped for the season. I like a calm and happy beeyard and the bees don’t seem to mind OA. I’ve seen bees fly in an out of the hive through the vapour without concern, unlike formic, which seems piss them off for days.  Plus, although occasionally a bee will get caught in the heating tray, there is little to no direct mortality as a result of this treatment.

So here’s what I do:

1.  I get everything ready on my trusty Lee Valley wagon before I close up for the season and leave it in the honey house so when I come back to do the treatments, I’m not hunting around for what I need:

a.  The vaporizer, a device specifically designed for OA (see photo), which I got from Propolis-etc.... The vaporizer connects to the 12-volt car battery.

b.  Container of oxalic acid and a little 1-gram scoop.

c.  Nitrile gloves, a mask with a N95 particulate rating and safety glasses. I can’t stress enough the importance of safety. OA vapour can be harmful to your eyes, nose and lungs, so you want to use safety equipment and be sure you are upwind from any vapour that escapes.

d.  A bucket for water (I bring the water when I come). The water is to cool the vaporizer tray after each use.

e.  Foam strips to close the hive entrance. You can use cloths, but I find the foam easier to manage. I bought a big piece of aquarium foam from Amazon and cut it into strips the width of my hive opening.

f.  A 12-volt battery. I had to replace the one in the photo since it was too small to treat my 25 hives in this temperature. A fully charged regular car battery works fine. I use this smaller one for a spare now. This is one item I don’t leave in the fall, I bring it with me to ensure it’s fully charged.

2.  I wheel my wagon to the beeyard so I don’t have to carry the battery and other equipment.

3.  I put a heaping scoop of OA into the vaporizer tray. My hives are 8-frame mediums, generally 3 supers high, so 1.5 g is enough. A general rule of thumb for 10-frame hives, though, is 1 g per super.

4.  After I remove the mouse guard, I position the tray into the hive opening so it’s about in the middle of the screened bottom board and then I put the foam in place. (see photo)

5.  I start my timer (I use an iPhone app) and then connect the clips to the battery. After 2.5 minutes I unclip from the battery and leave the vaporizer in place for another 2 minutes.

6.  I remove the vaporizer from the hive and drop it in the bucket of water to cool. (You don’t want to put the next batch of OA into a hot pan), leaving the foam in place for at least another 10 minutes (I don’t wait around for that, though, I move on to the next hive).

7.  Remove the foam to use on other hives. Replace mouse guard.

8.  I do this for each hive. I find it takes about 10 minutes per hive.

I do this twice a season when I am sure all the brood has hatched.  It doesn’t really matter how close the treatments are. This year they were a month apart, once in December and once in January, but they could be as close as a week apart.  The main issue for me is to get them done before snow accumulation makes it difficult to roll my wagon or reach my hives.

Provisions: Our house is closed up for the season, so I bring a snack I pick up on my way to the beeyard from my favourite local general store/bakery/luncheonette we all call ‘Jen’s’: This time: A thermos full of steaming hot coffee with fresh cream and honey and a big piece of lemon pound cake just out of Jen’s oven. I’ll have a late lunch at Miss Lily’s in Picton on my way home. A big bowl of soup, I think, with a warm buttered biscuit, and the local paper to catch me up.


Everything I need is on my trusty wagon.

Everything I need is on my trusty wagon.

The foam strips keep the the vapour inside (for the most part).

The foam strips keep the the vapour inside (for the most part).