>I'm confused here... haven't we already seen an Amitraz-resistant mite

> population arise, and didn't it arise pretty quickly?
>

Yes and yes!  The first reported resistance was way back when Miticur was
introduced; some beekeepers also were using Taktic or Ovasyn at that time
(and some have continued to use).  But amitraz largely fell out of favor,
and commercial guys used fluvalinate, then coumaphos.  When those failed,
they shifted to other chemicals, including back to Taktic.

And yes, upping the dose by the late 2000's.

>In contrast, despite the fairly widespread use of Mavrik (liquid
> Fluvalinate
> [Apistan], much cheaper than the Apistan strips) by the same demographic of
> stressed-out mid-size migratory guys, resistance to Fluvalinate did not
> appear for nearly a decade, and seemed to only appear as a result of the
> alternating with Check-Mite strips, creating the multiply-resistant mites?
>

Fluvalinate was nearly completely failing by the late 1990's in many
areas.  Beekeepers compensated by massively upping the doses, likely to the
detriment of the bees.  The last beekeeper that I know of to give Mavrik up
had used it for 17 years.

>
> >Regardless, the physiological attack of the organic acids is not likely to
> become less effective through a mutation/selection process, now is it?


That's a good question.  The modes of action of the organic acids are more
complex, so harder to develop resistance.  But there is no inherent reason
to exclude the possibility of resistance, especially if one considers
partial resistance.  Note that since the margin of safety between the toxic
dose for mites, and the safe dose for bees is so narrow, even partial
resistance by the mites could be a serious problem.



>   > I wish there were more focus on physiology, and less focus on nerve
> agents, as
> nerve agents always "create" a resistant population.
>

And I wish that there were more focus on behavioral disruption of the
mite.  Good targets would be mite olfaction, mating disruption, messing
with the ovulation signal, etc.

>>Once alleles for resistance are present in the population, then it is
simple math to determine the number of generations for that allele to
increase in frequency.
>This sort of statement usually comes from someone who is not familiar with
the topics of genetics, pesticide resistance etc.

It can also come from someone who is : )
The founding principle of evolutionary selection is always simple math.  In
practicality, the math becomes more complicated due to numerous variables,
but the principle remains the same.


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

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