>
> > The commercially-managed population is genetically bottlenecked, as are
> other livestock animals
> >We heard statements like this when people were first casting about for
> causes of large scale losses. I thought the notion was pretty much put to
> rest by this work:


Not to rest at all!  Dr. Steve Sheppard and others continues to follow
this.  Out of the entire US bee population of perhaps 4 million hives, the
vast majority of queens are produced each season from a relative handful of
breeder queens, by only a few producers.  This results, BY DEFINITION, in
genetic bottlenecking.

Do not confuse this with surveys taken across the U.S. that indicate
overall allelic diversity of the entire managed and unmanaged population,
compared to inbred local populations in Europe.  There is of course greater
overall allelic diversity in the U.S. due to our mixing of many of the
European races, plus the Africans.

But that overall diversity does not exist in the highly-bottlenecked
commercial populations, which are largely produced in only a few areas of
the country.

The above said, there is of course always some degree of genetic diversity
and recombination at any time.  Without such relatively rare alleles, our
bees would never have recovered from the invasion of tracheal mite (which
wiped out 70% of Calif bees), or *Nosema cerana *(which appeared to
correlate with losses in the early 2000's).  And look at my recent test of
seeing what proportion of my own stock appeared to exhibit resistance to
varroa--over 90% failed the test, but about 2% appear to demonstrate strong
resistance).  I'm counting on those rare alleles to save us from the mite!
So I'm going to continue to bottleneck my population so that those
currently rare alleles perhaps come to proportionally dominate.

-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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