>From:          Adony Melathopoulos <[log in to unmask]>
>
>It would be nice to have some continental European beekeepers comment on
>this.  I think the year the study was done when most German beekeepers were
>either using coumaphos (Perizin - a systemic added to syrup),
>bromopropylate (the Folbex smoking strip treatment), or formic acid.
 
I have forwarded this to Ingemar Fries, and is his answer follows below.
 
--
Regards
 
P-O Gustafsson, Sweden
[log in to unmask]    http://www.kuai.se/~beeman/
___________________________________________________________________________
 
 
The results presented on longterm effect on Varroa mortality from combs
where bees have been previously been treated with pyrethroids need to be
repeated to be confirmed.
 
Experiments with contaminated wax demonstrate that the effect of
pyrethroid
residues at levels you may find under field conditions has no measurable
effect on mother mites invading cells. With coumaphos it is another
story,
where even low levels may cause increased mother mite mortality (Fries,
Wallner & Rosenkranz, 1997, in manuscript).
 
About pyrtethroid tolerance in mites, all exposure will increase the
probability of tolerance development. The idea to contaminate the wax
with
acaricides is old and will not work. One reason is the barrier to
acaricide
diffusion caused by the bee larva cocoon. Another reason not to
contaminate
the wax with pyrethroids is that we at present know no methods to
"clean"
the wax. You may dilute contaminated wax, but the residues put in there
will not degrade.
 
Keep your wax clean,
 
Ingemar Fries
 
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Sweden
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