>Just wondering if the product Apivar with the active ingredient amitraz
been assessed by the EPA and California state for health hazards  and in
spite of potential health hazards  they still registered it for use.

> Am I missing something here?
>

I wasn't trying to be alarmist.  The acrylamide in roasted coffee and
french fried potatoes also makes California's Prop 65 list.  The regulators
(whom I trust) currently rate the risk of legal application of amitraz to
be acceptable.

>
> >The question then is: how many generations will take varroa to develop
> resistance using label doses vs home made recipes?
>

As best I can tell, resistance is not solely a function of generations.  It
is a function of random mutation and selective pressure.  There must first
be a mutation (which is random, but may be favored by epigenetic effects),
so unpredictable.  There are likely some resistant mites already out
there.

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.  If all beekeepers in an area use the same product
generation after generation, and if the efficacy of kill is very high, the
frequency of resistant mites will increase rapidly.  Under less selective
pressure, will increase more slowly if at all.


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

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