Bob Harrison wrote

> Another point to consider the varroa mite comes from the tropics(lots of
> heat and humidity). What happens when you change their environment by
> removing some of that heat and humidity? I do have the varroa(small
> amount)in my hives and don't treat at all,and my bees survive the winters
> and are very strong hives.

With the recent review of the varroa mite by Dr. Denis Anderson it is now
the case that the original Varroa jacobsoni did come from the tropics.
However, the varroa mite that is in hives of Apis mellifera around the world
is actually a newly described species Varroa destructor.  The one of the
main haplotype in this group comes from Korea which is certainly not
tropical.

Whilst I am not in a position to be able to comment on what happens when you
change the environment i.e. heat and humidity, I thought I should correct
the bit about coming from the tropics so this can be factored into the
equation when people are considering their responses.

Trevor Weatherhead