Schrodinger's Bees

Winter is a period when beekeepers don't do a huge amount of hands on beekeeping. It's a good time to clean up kit, drink some mead, pad out your blog with book reviews and so on but as far as contact with the bees go there's not a lot. Whilst beekeepers do their best to ensure their colonies will survive the winter we do seem to end up a with a Schrodinger's Cat sort of situation. Are the bees in the boxes alive or not? There's a lot that can happen to them over the winter. They could starve if they didn't have enough food stored or warm snaps made them use up what they had too quickly, they might get damp and die, varroa load may be too high or some other pest or illness may have wiped them out.

Anyone alive in there? Knock once for yes, twice for no.

I occasionally pull out a stethoscope and have a listen to my colonies just to be sure they're still alive in there. Hopefully the bees have been living on the honey stored in the comb of the brood box, but that may be running low by now so many beekeepers will feed their colonies a nice lump of fondant icing after xmas. Actually I got an email from Fragile Planet last week advising customers to feed their bees this winter. However I'd given mine some fondant back in November just in case it was needed and as I checked recently I was able to see most of it still there, it may be a little dry but condensation inside the hive should provide water to allow the bees to use it.

Lotta sugar and 3 bees. The brown stuff is a supplement.

Another thing beekeepers do when it's cold is pour acid on their insects. Sounds a bit strange, I know, but it's for the benefit of the colony. It's intended to kill the varroa mites. Normally most of the mites will be safely tucked away in the capped brood along with the bee larvae they're feeding on, however when it's too cold to raise larvae the queen stops laying eggs so the mites hang about on the adult bees instead at which point they're more vulnerable to varroacides, specificall organic acids applied to the bees directly. The January edition of the BBKA News advised waiting for a period of cold weather with an average of 5 degrees Celsius, lasting three weeks so any capped brood will have emerged. Then as the cold snap comes to an end you trickle a 3.2% oxalic acid solution and 1:1 syrup onto the bees between the combs. The bees between the combs are called a seam, and the figure people go by is 5ml of solution per comb. I suspect that's actually based upon the population of standard National hive brood box really and it may be that in a Commercial like mine you should use a little more but I decided to go with 5ml per seam for now. I think I read somewhere that the acid damages the mouthparts of the varroa leading to their demise, many believe it also does some harm to the bees but less than the varroa would do and given the short lifespan of individual bees shouldn't be a significant problem for the colony as a whole. The figure bandied about for efficacy of dribbling oxalic acid onto the bees seems to bea reduction of about 90% in the colony's varroa population.

Do not drink me.

A very weak solution of Oxalic Acid is used for this, other organic acids can be used such as Formic or Lactic Acid, but Oxalic is currently in vogue. It's legal status seems a little confusing to me, the choice of these organic acids as varroacides seems to be based upon them not having a defined Maximum Residue Limit like regular pesticides. I gather these organic acids occur naturally to some degree within bee colonies anyway and unlike other varroacides don't leave a residue affecting the hive products. It's not difficult to make up your own solution, but if you get it a bit wrong it could be a disaster for your bees either by not killing enough mites or by damaging the bees themselves -and do you really know how accurate your kitchen scales are? I doubt it.

If you really want to know more about varroa control DEFRA have a 44 page document available called Managing Varroa that you can download and includes Oxalic Acid treatments. There's other ways to administer organic acids such as spraying or vapourising the stuff. Vapourising seems wonderfully dangerous giving beekeepers the chance to find out first hand how much damage of a lungful of vapourised acid can do to a person, whilst simultaneously being less effective on the varroa. The advantage of vapourising it is it's faster to do than dribbling, although that doesn't take into account time spent waiting for an ambulance and further time spent recuperating after burning your lungs out.

Back to my bees. I've never used oxacilic acid before but you administer it by dribbling it from a syringe. It just so happens I'm no stranger to drawing up and administering solutions in syringes, and it's easier without a needle involved.

My table needs a clean

Today the temperature below the hives was 8 1/2 degrees Celcius, the warmest it's been for a few weeks so I decided to apply the acid -it was also due to expire next month too. After lighting the smoker and popping on my smock and veil I decided to treat the bees in the nuc first. As I said above it's hard to know how the bees are doing over winter despite best efforts in the lead up to winter so it was something of a relief when I removed the nuc's crownboard to see bees in there under the fondant and more coming up from the seams to see why some fool was opening their hive in late Janury.

They're alive!

There looked to be four seams full of bees. In the photo you can see three of them, the edge seam on the left was also full of bees but they'ed propolised the top edge so you can't see them so well in the image. The two seams on the right were more or less empty of bees. Interestingly (slightly) the left side of the hive is more exposed with the right side facing Hive1 so I'm assuming they found it easier to keep warm on the left of the hive than the right. I drizzled 5ml of oxalic and syrup solution into each of the four occupied seams making 2 passes for each (2 1/2 ml per pass) rather than drowning them by trying to apply it too quickly. I had some spare brood frames with honey on that I'd stored in the summer in case it was needed in the winter. Rather than disturb the frames the bees were on I prised out the rightmost frame to assess their stores but found it still had capped honey in it, so I guess they're not short of food and that probably explains why they've shown little interest in the fondant so far. Closing up the nuc I cracked open Hive1 where I was greeted by a few bees and saw them crowded into the seams again. I drizzled 5ml of solution into each seam before moving on to Hive2.

"It's January, put the lid back on you muppet!"

In Hive2 I could still see some grey bits of Api-Life Var on the outer corners of the frame tops. This is a crumbly material holding thymol (thyme essential oil) which as it evaporates kills varroa but not bees -although it does annoy them. Normally the bees would have broken it up and thrown it out of the hive by now but with the cold weather I'd guess it's not been evaporating so I pulled them out. There were a few bees on top of the frames and investigating the fondant. Not too many though. If there'd been a lot of them then it would be an indicator that they were starving -I suspect they'ed've eaten the fondant before that was a problem though. Once again I trickled the solution over the bees and closed up. You can see in the above photo the bees are towards the far side of the hive rather than in the middle.That side of the hive whilst nearer the entrance is more sheltered from the elements as it face a garden wall whereas the other side faces the garden. Evidently they've chosen the warmer side of the hive to cluster in. Hive1 had done the same.

Oxalic acid applied and all the hives closed up again I popped to Pearson Park for a quick run. Apart from an occasional check on how much fondant they have left I'll be leaving the bees alone from now till spring.