In article , zxcvbob wrote:

I went to the state fair today, and while looking at the exibits in the
Horticulture Building, I asked a bee exhibitor how the bees were holding
up against the varroa mites. He said the mites are becoming resistant
to miticides, and they are mainly using "essential oils" now, along with
new and improved miticides, so they probably have about 3 more years
that they can treat the mites before all treatments become ineffective.
Now here's the good part. They found some honeybees that have adapted.

The worker bees search for infected brood cells and destroy them.
Using artificial insemination, they are breeding bees for this trait.
It will take a couple of years to build up sufficient stock of the new
mite-resistant bees, but that's probably about how long we have anyway
with the existing treatments.

All this is based on a conversation I had with one exhibitor at the MN
State Fair, and I don't know what his credentials are, so do your own
research before taking this as gospel. But it's encouraging.

Best regards,
Bob

Varroa resistant queens were obtained from Russia by the USDA in 1997. The
Russian bees had been exposed to the mite for a century so had that long
to learn to deal with the parasite. But they're by no means 100%
resistant; varroa can still take down a hive. Strains that have been
crossed with the Russians are improved for verroa resistance but never
immune. The resistance is caused by these bees' "clean up" behavior rather
than by any actual immunity; in addition to these bees recognizing &
discarding infested larvae very quickly, they also have mutual grooming
habits that remove the mites. Plus they have shortened time for brood
development, getting ahead of the curve of infestation damage.

Here's an article about the Russian bees:
http://www.ars.usda.gov/is/AR/archiv...9/bees0899.htm

Here's the team that has been working with these resistant bees:
http://msa.ars.usda.gov/la/btn/hbb/staff.htm
They are now being bred at a half-dozen University experimental stations
plus an increasing number of commercial beekeepers. For anyone new who
wants to join the bandwagon, the going rates are $500 per breeding queen,
$250 per queen tested for breeding & probably ready to have at it, or $75
per queen not tested for breeding capacity, available through this
company:
http://members.aol.com/queenb95/catalog.html

Use of miticides has always been part of the problem. Given time and an
ABSENCE OF MITICIDES, American bees would have developed amunities similar
to the Russian bees. But because of the use of miticides, the bees were
never able to adapt, while it has instead been the mites that are
adapting. As usual, chemicals are not the best answer. Wild bees in
Arizona & Texas parklands have made small but measurable come-backs after
the initial mass die-offs, because proving bees not treated with miticides
are been able to adapt to new threats, but the wild honeybee population
also had to adapt to the presence of aggressive Africanized bees by
changing their behavior; for instance, they will estivate great lengths of
time if during droughty conditions there aren't enough flowers for both
kinds of bees, & other behaviors to help them avoid conflict with the
aggressive bees & fit into a narrower environmental niche.

The resistant southwest feral strains were not generally the preferred
bees for breeding programs because of the weight of behavior traits not
conducive to captive requirements. Because they learned not to gather such
reserves of honey that they would fall into conflict with Africanized
bees, they'd be poor captive honey producers compared to the Russian bees.
Plus there are hybridized southwest bees very resistant to the mites but
insufficiently gentle for captive purposes. Though the older honeybees
will never return to the Southwest in the numbers seen pre-varroa &
pre-Africanized bees, it is the aggressive competitors rather than the
mites that will keep their numbers less. But the amazing factor is how a
combination of verroa & other parasites, drought, & aggressive
competitors, could not keep the southwest honeybees from surviving,
adapting in the same decade that northern bees exposed to miticides merely
became increasingly reliant on miticides that become decreasingly
effective as super-varroa mites adapt to the poisons.

Adaptation of Southwest bees also happened in untreated tame colonies, &
varroa-resistant strains were being bred there even before the Russian
bees arrived through the USDA. By 1998, with breeding programs only four
years old, already zero damage was being reported for some hives never
treated with miticides. As with the Russian strain, it is hygienic
behavior that helps them servive the mites, & speeded up maturing process
for larvae. Here's an article on the varroa-resistant bees identified in
Arizona even before the arrival of Africanized bees:
http://gears.tucson.ars.ag.gov/rf/abj/varroa.html

It's not yet wholly in the bag, but it does look like the days when it was
possible to maintain hives for years without special treatment for
parasites will eventually again be a reality.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
Visit the Garden of Paghat the Ratgirl: http://www.paghat.com