It was good to see all the discussion generated from the post.  I am of the
same opinion as Tom Barrett and Robert Brenchley; if varroa were introduced
to a population of European honey bees the two species would evolve towards
a more benign relationship.  Strong support for this argument is that the
closest relative of A. mellifera, A. cerana, has had a much longer
relationship with varroa (V. destructor) and the relationship is far less
damaging to the host than it is in A. mellifera.

Dr. Ewald's ideas are interesting in understanding how diseases and  hosts
have evolved in nature.  Applying Dr. Ewald's ideas to managing pest in
honey bees, however, would take considerable thought and, in agreeing with
Peter Borst, would not be the most fruitful immediate area of practical
study.  I am convinced of Robert's wisdom in stating we first and foremost
need a new acaricide, and very quickly behind it, research into how to limit
acaricide use, such as a good breeding program.  Nonetheless, it is
interesting to note, Dr. Ewald's theories are proving fairly robust in
predicting how cholera evolves virulence:

Ewald on cholera:
'Theory holds that water in which microbes can thrive serves as a vector
that lets dangerous virulence continue or worsen.  On the other hand,
treated water would kill cholera strains relying on diarrehea for transport;
only mild strains would survive because their hosts would be healthy enough
to transmit the pathogen to other people. 'Essentially this is what happened
in 1991,' Ewald says, referring to a cholera outbreak in Peru that spread
through Latin America.... [He and his students found] that over the 1990s
Chlie's cholera [whose water was trustworthy] did indeed become less
virulent, wheras highly toxic strains persisted in other counries [Peru and
Guatemala, whose water is unsafe].

So, perhaps the idea should not be poo pooed (pun intended) all together,
and may yet serve honey bee pest management.  As Peter pointed out, the area
obviously needs more study and thought before it has applications to bees,
as I imagine Dr. Fries and Camazine, the authors of the Apodolgie article on
the same topic, would heartly acknowledge.  All ideas, after all, need a
place to start.  At the very least Dr. Ewald's theory gives us a new way to
think about why certain bee parasites or diseases are virulent and why
others are benign, which, in my opinion, is a good days work.

PS I liked Dick Allen's question about what the theory means on varroa
vectored viruses.

Regards,
Adony


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.306 / Virus Database: 166 - Release Date: 12/4/01