>
> > They both stated unequivocally that trying to breed mite resistance in
> European bees is bound to fail. Whereas, feral bees from both these regions
> as well as the southern USA already have mite defenses, which no doubt
> could be enhanced.
Pete, the latest evidence is that European bees (A. mellifera) evolved in
Africa, and moved into Europe via Morocco. So I see no reason to suspect
that in the process they lost the genetic and epigenetic potential to
evolve resistance to varroa, as have at least some races of A mellifera in
Africa.
I've personally observed A mellifera ligustica phenotypes that exhibited
clear strong resistance to varroa. If such resistance can be seen in one
colony, why would anyone feel that it could not be bred for?
Charles, when left to their own means, bee populations have been shown to
develop an entire suite of strategies to resist varroa. I see absolutely
no reason to think that it is impossible. In general, I've seen the entire
U.S. bee population shift toward greater resistance already. For those of
us who were keeping bees when varroa first invaded, the population growth
rate of the mite in colonies was incredible, far greater that what we tend
to see today.
Lionel, of course we see flea resistant cats and dogs. One simple
behavioral change--shifting nest sites--would make them highly resistant by
preventing vertical transmission. Thicker, denser underfur makes them more
resistant.
>The actual "Bond Method" involves the deliberate introduction of
overwhelming varroa
pressure, such as moving in large amounts of drone comb, and doing nothing
to help the bees cope with the varroa. This is done in the (vain) hope that
the survivors will show useful mite-resistant traits.
With the greatest respect, I must disagree. The Bond method is to "live
and let die." It worked very well for the development of varroa resistance
in Africa in Apis mellifera. It worked in Primorski. It worked for
Kefuss. It's working in feral populations all over the place.
It won't work if there is not enough genetic and epigenetic diversity to
begin with. Santa Cruz island is a case in point.
I am not a promoter of the Bond method--to wasteful of bees, unless you
have a huge feral population (as in Africa or South America) that can allow
it to work on a large scale (the results in those areas are pretty obvious).
Re transgenerational inheritance, there are numerous examples of
multigenerational temporary inheritance. If such regulation affords
increased fitness, random (or nonrandom) mutations may eventually lock it
in genetically. But there is no reason to discount the possibility of
environmental resetting of such epigenetic inheritance each generation, so
long as such environmental trigger exists (e.g., drought, heat, parasite or
nutritional challenge).
>To most commercial beekeepers if you plan to control
varroa in your hives keeping a pure line of Russian bee is more work than
interested in.
You hit the nail on the head Bob. And so long as chemical control is cheap
and effection, there is no short-term economic pressure on the queen
producers to produce mite resistant stocks.
>And we think that bees and varroa are going to just magically co-evolve in
30 years?
Hardly magic. As Alsopp has strongly pointed out, it is humans that have
slowed the process. In South Africa, such coevolution to a stable
host-parasite relationship took less than a decade for two races of Apis
mellifera.
--
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com
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