In article <[log in to unmask]>, Adrian Wenner
<[log in to unmask]> writes
>   For instance, in our immediate metropolitan area (Santa Barbara, CA) we
>have had an impressive resurgence of feral colonies, despite the fact that
>we know of no beekeepers within this area.  Somehow, these feral colonies
>have survived the varroa mite onslaught --- as witnessed today, when I
>found that a new swarm had moved into a cavity in the base of an olive tree
>(downtown Santa Barbara, corner of Olive and Haley Streets) within the past
>week, a cavity repeatedly occupied these past few years.
>
>   To repeat:  We apparently have no beekeepers in this rather vast area
>(from the ocean to the top of the mountain range), beekeepers that keep
>their colonies alive with Apistan strips.  Yet, we now have a great many
>really viable feral colonies in this area, colonies (collectively) that
>cast out swarms regularly.
 
I think I would need more substantial evidence of resistance than this
before comitting to the strategy of securing matings only with similar
feral colonies. (As no doubt does Adrian, with his scientific
background)
 
Reason as follows.
 
Swarms issuing forth during the peak breeding season tend to be
relatively clear of mites, as the vast majority are in the brood at this
time. Thus a fresh, relatively clean swarm can run for anything up to
four years before it collapses.
 
During its lifespan it may issue quite a number of further swarms and
castes itself, each again leaving much of the mite load behind at the by
now parent colony. This parent colony then collapses, and much (except
those moved on by absconding bees) of the mite load dies with it.
 
This will mean that strains disposed towards swarming will be very
strongly selected towards, as the non-swarming colonies collapse having
issued relatively few progeny, to be replaced by the numerous swarms
from those colonies of a swarmy nature.
 
It will only take a very few seasons for this strain to become dominant
over the less vigourously swarming types generally produced from managed
colonies.
 
It does not mean that the bees are necessarily any more resistant to
varroa, just that they go through this regular cleansing and renewal
process in the form of swarming. The parent colonies collapse as normal,
but are soon replace by further swarms occupying the same space.
 
Although the reasons for the olive tree site falling vacant, and then
regularly being re-filled, are not given in your posting, one possible
reason is this process, which will also produce the noted rebound in
swarm numbers some time after 'first wave'.
 
Such a scenario may, of course be part of a way forward in the absence
of treatments (such as in organic regimes), taking advantage of the
swarming behaviour rather than trying to suppress it, especially if true
resistance fails to materialise.
 
On the other hand, deliberately seeking out swarmy bees will undo many
years of diligant queen breeding for easily managed colonies. As high
swarming becomes normal management will of necessity become more
intensive.
 
Several other posters have touched on this feral survivor situation
before, and it may well be there that the first resistant colony is
found, but it will really need to be a colony which exists untreated
continuously in one location for several years. It must be properly
demonstrable that this is not the result of unobserved re-occupations of
the same spot. Then we may have some genetic material there worth
researching into.
 
Kind regards
 
Murray
--
Murray McGregor
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