> On observing the almost total loss of healthy colonies in this area, this
> fall, (SW Virginia, USA) (untreated) I wonder what Varroa does normally
> with it's host: since a dead hive means the end of that Varroa population
> as well.
 
Our honeybee is not the normal host for varroa, and negotiations for
symbiosis have not yet been completed.  In its normal host, there is
a balance and both seem to prosper.
 
> Might we see selection for Varroa that over-winter in temperate
> climates independently from their host, as well as for
> honey bees that tolerate Varroa infestation?
 
Although the former is *perhaps* possible, the latter is far more
likely.  Accompanying this (latter) adjustment by honeybees, we
would expect to see an adaptation on the part of the varroa, where
strains are fairly quickly selected that are not lethal, and in fact
allow adapted strains of honeybee to prosper.
 
Varroa's destruction of the competition in the form of non adapted
honeybee strains, could be regarded as a benefit to the surviving
bee strains.  However, this adaptation to mites might well come at
the expense of some characteristics that we consider desirable in
bees.
 
One factor that affects and perhaps prevents the adaption process is
the interference by mankind by means of mite management techniques.
 
These attempts skew the process and may well slow the process by
destroying the less harmful strains of varroa and encouraging the
hardiest varroa to survive.while at the same time encouraging
continuation of susceptible (weak) strains of honeybees.  This is
exactly the opposite of the process nature uses to accomplish
adjustment between the species.
 
Of course, non of us are likely to sit by and watch our thousands of
hives dwindle to the tiny number (which could be zero) that can
resist the current varroa, so that we can rebuilt from that tiny
remnant of adapted colonies.
 
Unfortunately any attempts by feral bees to adapt, are likely to be
swamped by the large numbers of domesticated drones in most areas
that will support bees - drones from pampered and protected stock.
 
FWIW, It is entirely possible that - rather than prohibiting imports
- we should be importing varroa mites and bees from areas where
honeybees have been exposed to varroa for some long time with minimal
interference by man in hopes of finding and introducing a less lethal
strain of mite and a more resistant type of bee.
 
Unthinkable?
 
Season's Greeting to all.
 
 
Regards
 
Allen
 
W. Allen Dick, Beekeeper                                         VE6CFK
RR#1, Swalwell, Alberta  Canada T0M 1Y0  Internet:[log in to unmask]
Honey. Bees, Art, & Futures <http://www.cuug.ab.ca:8001/~dicka>