> >Randy am I interpreting you correctly in that after a while DWV will not
> be a problem?
>

Sorry, no.  The most virulent strains of the other viruses will be weeded
out, then leaving DWV as the main player--if varroa levels are allowed to
climb in your colonies.  If varroa levels are kept very low all year long,
then virus dynamics go back to something similar as before varroa.

>
> >Our position is that we hope that when varroa arrives it does not carry
> DWV.
>

Good luck with that : )  Make sure that Biosecurity only allows a mite
without DWV to be the first one allowed into your country.

>
> > Note that in South Africa, despite varroa having been there for nearly
> 20 years, DWV is apparently not an issue.  Very strange!
> Could this be because they are either capensis or scutellata and not the
> bees we keep?
>

I'm not clear on this.  I haven't seen research comparing the innate viral
resistance of those subspecies to the European subspecies.

A big question to me is why our bees haven't developed full immunity to
some of these viruses.  Is it because the viruses are continually evolving
new strains, as does influenza virus in humans, or is it something else?
We still have much to learn...

-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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