Malcolm’s Topical Tips – 2019 May 19

“Bee viruses and the damage they can do to our colonies” - by Malcolm Wilkie

Above is a dead queen cell larva removed from one of my hives today. This was the only queen cell I had left in the colony so I will now have to find a queen cell or a virgin queen to bring this colony back from the brink.

This virus is black queen cell virus and only affects queen cells. Worker and drone larvae are not affected.

On the positive side at least I am on the ball and so with this colony I had gone in to check the cell and as it was still sealed (and that was a week after my calculations that it should have hatched), I opened it up and found this dead larva.

I know we tell beginners to leave everything well alone when a virgin is emerging (there is always a danger of squashing ‘her’ if one is unlucky). However, I only gently go into the hive and then go straight to the frame I marked with the drawing pin. Of course, if I have heard a virgin piping (yes, I always do listen) I don’t disturb. So, the positive is I know I need to do something.

We teach beginners about DWV (deformed wing virus). Varroasis (having let varroa get out of control) is a sad sight to behold with dead pupae half emerged from their cells with their tongues hanging out. Varroasis would be the consequence of ignoring DWV.

The worst to behold is chronic bee paralysis virus. This is even more upsetting as the bees all quiver and shake. Usually destruction is recommended although Helen Hadley and Peter Coxon have managed to successfully turn around a colony. But what you have to do is brutal.

There are also many other viruses and they are prevalent because varroa transfers viruses between bees, and so something that would naturally only ever be a background problem can suddenly get out of hand.

We all need to be aware of problems that occur and strive to keep healthy bees. Changing comb, treating against varroa if necessary, shook swarming, giving feed if suddenly there is a dearth of nectar in the environment, making sure in August that the bees emerging are in tip top shape to carry the colony through the winter and of course feeding properly in September.

There are also products which promote bee health such as Hive Alive and these also can be used and, in my experience, seem to boost the number of bees you get in a colony.

Malcolm Wilkie 19th May 2019

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