> Prior to the rapid evolution of the viruses that could take advantage of
> the novel vector, we could allow varroa infestation to climb to levels that
> would be unimaginable today.  That observation alone suggests that the
> problem is mainly viruses, not varroa alone, and that without the presence
> of mite-adapted viruses, that even a substantial degree of parasitism by
> varroa can be fairly well tolerated by a colony.
>

What is interesting about this discussion is that it is a perfect
chicken-egg  question.

Before mites, KBV and bee paralysis virus were in hives but were in the
"novelty" category. They were tied to Trachel mites but supposedly not as a
vector but just that they diminished the bees immune system to allow the
virus to do the coup de grace. As Randy noted, Varroa changed the game as
the viruses took advantage of Varroa's "novel vector" (great phrase).

My guess as to varroa resistance that disappears when the bees are brought
into a new habitation is simply that they clean out the viruses in the old
location by the classic host parasite collapse and get relatively virus
free. Put them in the new location and the pressure returns.

Bill Truesdell
Bath, Maine

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html