Sunday, 10 August 2008

Chemical Varroa Treatment

Sunday 10th August

A sunny day but very gusty. Not ideal conditions for opening the hive but we have an important job to do today - the chemical treatment against the Varroa mites. The weather seemed to be affecting the bees' mood - they were definitely not happy today. They don't normally sting unless they have to - instead they fly hard at your head or buzz angrily in front of your face. If it weren't for the necessary treatment today we probably wouldn't have bothered carrying on - it's not much fun inspecting a colony that actually would prefer you to just go away!
Anyway, it just so happened that there were a number of unusual things to see today so it all took a while. There are two new things to see on this frame:
The first thing is easy to spot - a queen cup - in the top right:
I hope this isn't anything to be concerned about. The bees make this super-sized cell to grow a new queen. This means that either they want to swarm (the current queen leaves with half the bees and half the honey, leaving the remaining bees to grow a new queen) or they're not pleased with their current queen and want to raise a new one to kill the old one. The queen doesn't lay a special queen egg - the worker bees will just take a regular egg from another cell and grow it into a queen by feeding it nothing but royal jelly. This super high-protein diet means the difference between growing up to be a regular female bee with a six-week lifespan and being a queen bee, living for over four years! Anyway, whatever their motives are, it's too late in the season to allow this to happen so I cut off both the queen cups I saw today.
The second thing isn't so easy to spot from a distance - a fully-grown drone bee:
This guy is huge! He dwarfs all the female bees, even the queen would look a bit weedy next to him! He has these vast oversized eyes and huge wings because he has only one job in life - to spot a virgin queen bee about 50 feet up in the air, catch her, mate with her, then fall back to earth dead!
Anyway, on to the treatment. Early August is the time beekeepers normally do their chemical treatment against the Varroa mites. The reason for this is that the treatment does taint any honey in the hive and by now the honey harvest should be all over for the beekeeper - any honey stored from now on is strictly for the bees!Of course it's not possible to use anything too toxic or insecticide-like for fear of damaging the bees - what we use is Thymol. I'm not much of a scientist but I believe it's similar to the stuff you find in decongestant lozenges. What happens is that the container of Thymol gel is put in the hive and the hive is then sealed up (as much as is possible - you have to leave a small hole for the bees to get in and out!) for two weeks.
Inside the hive the fumes knock out all the mites and it doesn't harm the bees (though it does affect their productivity as they rely on scent to communicate).
Unfortunately this treatment can only affect the exposed Varroa mites - any inside the sealed cells still are completely unharmed. This is why the treatment has to be on for a number of weeks, so that all the mites still unhatched have time to emerge and then be killed by the fumes. I put the pack on then closed up the hive, reducing the entrance hole to its smallest setting. After a fortnight we'll repeat the whole process and then (in theory, at least) every single Varroa mite will have hatched out and been done in by the Thymol before it has a chance to lay any more eggs.