> But this still leaves you on the treadmill of constantly trying
> to kill varroa.  My original post asked whether any work was being
> done to identify variation in susceptibility to viruses.

A few points about viruses may need to be stressed in all
this speculation.

Viruses (for example, influenza, "the flu") are very difficult to
fight due to their moving-target nature. New strains of human flu
appear yearly, and they vary in virulence.  Regardless, influenza
kills millions every year.  There is no single shot that can protect
one from both last year's flu and this year's flu.  Every year's
influenza vaccine is an ad-hoc, custom-designed mix of multiple
"killed" viruses that mimic the viral surface antigen(s) that mediate
binding to the host cell.  (This is a whole lot like matching
crystalline structures.)

With bees, vaccines are assumed to be impractical.  It has been shown
that viruses are spread between varroa through bee larvae when the
varroa feed on the larvae.  It has also been shown that there is a
direct correlation between the number of adult varroa feeding on any
one bee larvae and the odds of the bee getting a virus.

The kicker is that if an infected varroa feeds on a bee larvae, all the
other varroa feeding on that larvae get the virus, and one has a sudden
upswing in the number of virus-carrying varroa just when varroa populations
are high enough to assure multiple varroa entering each brood cell.

If one can keep varroa populations "under control", one avoids the
overwhelming outbreaks of viruses, as the viruses are not known to
be spread by other means anywhere near as easily.

So, to summarize, if we could deal with viruses easier than we could
deal with pests, we would have done so for human viruses.  If we could
breed domestic animals that were somehow resistant to viruses, we would
have breed poultry that were resistant long before now.

We haven't because we can't.

Calling the current approach a "treadmill" does nothing to advance
understanding.  Beekeepers are just now starting to get the message
that one must monitor varroa populations, a message that the
researchers and extension people have been pushing for years.

So, in these troubled times, perhaps we all need reminding that
when we all work together and really put our minds to something,
we still can't achieve the impossible.  :)



My personal dilemma has to do with the "economic threshold" as
applied to beekeeping -

a)  Assume I have a colony that presents a very low, but
    non-zero mite count in fall.

b)  If I decide not to treat that colony, I certainly will
    have a higher initial mite population next spring, which
    will give that colony's varroa a "head start" on colonies
    that are treated, and can be assumed to start in spring
    with a zero (or very near zero) varroa population.

c)  There is a very good chance that this untreated colony
    will have to be pulled out of production in summer to
    be treated due to the "head start" I gave the varroa
    by not treating in fall.

d)  There is also a good chance that this untreated colony
    will become the source of varroa spread to the treated
    colonies via drifting bees.

To me, it seems that it is not a question of "if" one should
treat a colony, but instead, a question of "when", except in
the unique and rare case of no detectable varroa at all.
Clearly, the worst-case economic impact for a honey producer
would be to not only spend money on treatment, but also be
forced to pull a colony out of production to do so.

I have asked several card-carrying experts "...and what happens
THEN?" when they get to the point in their presentation where
they talk about making a decision about treating or not treating.

I have yet to hear a coherent response that has any good news
for next mid-summer's crop from this low-varroa-count colony.
They can think ahead as far as next SPRING's crop, but if asked
to think about the SECOND honey harvest of the season, they start
to act like small mammals cornered by a lynx.


       jim (Political skill in the absence of
            statesmanship is the first act of a tragedy)

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