Harry wrote

> With regard to varroa and heat.  I understood that varroa mites die if
> exposed to a temperature of 45 deg. C.  (The temperature might be wrong I
> would have to look it up to confirm this)  A few years ago now there was a
> lot of discussion about heating hives and numerous experiments were carried
> out in Germany.  It was claimed at the time that exposing the varroa to heat
> not only killed the mites on the bees but also those in the cells. Perhaps
> new research has proved this wrong but I have not been made aware of it.

I had a visit a few years ago from a lady beekeeper from Germany who, while at University, had been involved in the experiments to see if they could heat a hive to kill varroa.  She told me that it was possible to do this but that the temperature was very critical if you wanted to kill the varroa and not kill the brood in the hive.

The conclusions were that it was possible in a laboratory to do this but that when it came to a field situation, it was not possible to keep the temperature at the critical point where the varroa was killed and the brood was not.  The equipment was not available to do this.

Trevor Weatherhead
AUSTRALIA