Hi Al and Everyone,

******************************************
Blane White
MN Dept of Agriculture
[log in to unmask]

>>> [log in to unmask] 01/02/01 09:13AM >>> wrote in part:
>
> Providing there is a lage enough selection pressure and the benefits
> outweigh the costs, organisms mutate through natural selection. FACT.
> Any and all treatments to control "pest" populations
> represent a type of
> selection pressure. FACT.
> Because of its many benefits of bee safety, low residue
> profile, proven low
> mammalian toxicity profile etc etc  Apistan (or illegally
> Klartan/Mavrik)
> was and indeed still is the most popular hive treatment for varroa
> worldwide. Incredible selection pressure. FACT.

[cut]

> It is noone's fault that resistant varroa emerged, it is a
> natural process
> of evolution. The uncontrolled dosing did however greatly speed up the
> process.

"I get a little confused on these evolution things. I always thought that
"mutation"
was a random event. Pressure then caused selection on the population. If the
mutation gave a
reproductive advantage then those that had the gene may survive and
reproduce better than
the ones without the gene."

No wonder you are confused the term "evolution" used in this context is just plain wrong and confusing.  The correct term is adaption.  Resistance is always present in the population at very low levels and the selection pressure of the treatment brings it to the fore.  No mutation needed just selection.  The result is a resistant population.
Now Max, from what it appears to me here in the USA, anywhere in the world where fluvalinate in any formulation has been used for about 10 years for varroa control resistance has developed.  Since we are selecting for the same traits in the population, I would expect the curves to be very similar or the same where ever the selection has occurred - this is the evidence that mutation is not involved just selection of pre-existing resistance.  Apistan resistance occurred here in MN and was documented first in one of the beekeeping outfits who had varroa first and was therefore using apistan longest ( and yes I am very confident they were not using other (illegal) treatments.  Apistan selected for the resistance at about the same rate as other formulations of fluvalinate in other parts of the world.  Don't get me completely wrong there are many very good reasons to use Apistan instead of those other formulations such as contamination of honey and wax etc. but in terms of selection for resistance I really see not difference.

FWIW

blane