If you haven’t already started your end-of-summer varroa treatments, then you will be thinking about it now.
Here in Southeast England the heatwave ended the nectar flow earlied than usual, so I’m going to get started on the treatments.
First, work out the size of the varroa problem
I don’t routinely treat my colonies with varroacides at this time of year. I usually prefer to first do a mite count in each colony to see if a treatment is needed.
This approach can be risky, because you need a reliable method of obtaining an accurate varroa level. If you get it wrong and underestimate the varroa population – well, you know what can happen, and how devastating it can be.
The most accurate way of measuring varroa levels is actually an alcohol wash BUT this has the drawback of killing the bees that are used for the test.
So this year I chose to use the sugar roll method which also has good accuracy and doesn’t kill the bees.
Equipment needed for a sugar roll
I was inspired to try this method when Paul (my Beehive Jive co-host) gave me a kit from the University of Minnesota, which was put together to promote the sugar roll method that they developed.
It’s a really handy kit in a plastic tub that contains everything you need to do a sugar roll: a scoop to measure the right number of bees for the test (approx. 100 bees), a plastic ‘jar’ with a wire mesh lid to roll the bees in, icing sugar, and the tub itself, to shake the icing sugar and mites into at the end.
Obviously you could assemble the kit yourself very easily.
Simple and effective
The sugar roll is so simple: shake the bees from a brood frame or two into the plastic tub, then fill the scoop with bees and put them into the jar with the lid on. Just make sure that the queen doesn’t end up in there!
Put approx. two tablespoons of icing sugar into the jar, through the mesh, using your hive tool.
Then simply roll and shake the bees in the jar until they are coated with the sugar. Leave the bees in a cool place for a couple of minutes and then . . .
THE FUN PART: shake the icing sugar out of the jar, into the plastic tub. You can literally see the mites shaking out amongst the sugar! Scary but fascinating!
THE SERIOUS PART: count the mites that have shaken out into the tub (I find it easier to do this if I first spray some water into it). If there is brood in the colony when you do the test, you must then
DOUBLE the number of mites that you have counted.
The sugar roll method is essentially telling you how many mites you have per hundred bees. If the result is more than 10-12 mites per colony, you need to take action immediately.
Once you’re done, tip the bees in the jar onto the tops of the frames. They will look slightly dizzy but will be fine!
A win-win method for the bees and the beekeeper
I love this method because it’s simple, clean and almost instant. Just what you need when making the decision about how to manage your colonies at this crucial time of year, when the winter bees will start developing.
In the past I have used the varroa drop method, where you count the mites that drop onto the tray through the open mesh floor. I never felt completely confident about this because often it was difficult to find the mites amongst other debris on the tray, and some colonies seemed to clean the tray, so I had no idea how many mites were there to begin with.
It’s worth noting that the sugar roll is not the same as when you dust the bees with icing sugar to encourage them to groom their mites off. The sugar roll is a different method and an accurate one.
So, thanks to the University of Minnesota for this simple way of getting an accurate varroa reading in just a few minutes, without harming the bees.