Sorry Olda, but there may be some confusion here. Please see my comments
below:
 
In message <[log in to unmask]>, Olda Vancata
<[log in to unmask]> writes
>> Gabon tapes contain acrinathrin which is very closely related to
>> tau- fluvalinate, the active ingredient in Apistan/Mavrik/Klartan
>> and to flumethrin, the active ingredient in Bayvarol and Bayticol.
>> It is proven that there is a cross-resistance in varroa to all three
>> substances. This means that if there are pyrethoid resistant mites,
>> Gabon will be no more effective than Apistan or Bayvarol.
>
>Varroa will probably develope resistance to all pyrethroids. It's
>probably  matter of time. But as I know, the tests  - so far -
>showed that varroa resistant to Apistan was not resistant to Gabon.
>Not yet.
 
Professor Norberto Milani of the University of Udine, Italy proved
conclusively in 1996 that there is a cross-resistance (in varroa)
between tau-fluvalinate, flumethrin and acrinathrin. This is published.
 
If you are getting control with acrinathrin then chances are you do not
have a large proportion of pyrethroid-resistant mites in your colonies.
It's not to do with "non-acrinathrin resistance" vs "other pyrethroid-
resistance". Just "not-many-resistant-mites-here" phenomenon!
 
>
>Talking about relationship of pyrethroids (your statement
>'acrinathrin which is very closely related to tau- fluvalinate' can
>be discussed...) is simillar to talking about relationship between
>antibiotics. It does exist bacterias which are resistant to some
>antibiotics and so far not to others. So far we can't say if some
>bacteria is resistant to one antibiotic, it's resistant to all of
>them. So far.
>
I agree about the antibiotic scenario, but I wasn't talking generally;
there is direct evidence of this pyrethroid cross-resistance with
varroa.
 
>When talking pyrethroids relationsship you must think that Gabon is
>- let say  - a 'second generation' of pyrethroids.
>
As is tau-fluvalinate.
 
>Take for example a look at the dosage for one beehive (mentioned
>before):
>Apistan: around 1000 mg (different in different countries )
>Gabon: 0,1 mg
>
Two Apistan strips should be used per hive treatment, each containing
800mg tau-fluvalinate. However, the actual treatment is not 1600 mg tau-
fluvalinate. The strip is heavily loaded so that a constant release of
active ingredient at a very low level is effected from the strips. The
actual amount of tau-fluvalinate that reaches the bees/varroa is
miniscule but the high loading is necessary to give the release pattern
from the reservoir within the strip.
 
I don't have information on the Gabon formulation.
 
>I even mentioned before - toxicity for bee/varroa
>fluvalinate: 2x
>acrinathrine: 200x
 
I'm not sure what you are saying but let me clarify that the safety
margin for tau-fluvalinate between killing varroa and killing bees is
20,000 x. This means it is "safe" for bees but toxic to varroa mites.
 
Can you clarify what the situation is for acrinathrin.
>
>Lot of people are concerned about residues (when talking pyrethroids -
>in wax which can be present in honey ).
>
>LD50/man
>fluvalinate (Apistan ): 250 g
 
LD50 tau-fluvalinate = >3000 mg/kg
 
>acrinathrine (Gabon ): 280 g
>(compare with salt (NaCl) - 200g )
>
Acrinathrin LD50?
 
>ADI/man (Acceptable Dayly Intake ):
>fluvalinate: 7 mg
No
The ADI for tau-fluvalinate for a 70 kg man is 0.7 mg per day
 
>acrinathrine: 1,4 mg
>
?
>NOEL /man (NO Effect Level ):
 
>fluvalinate: 70 mg
NOEL for tau-fluvalinate is 1 mg/kg/day
 
>acrinathrine: 210 mg
>
?
>\vov
 
--
Dr Max Watkins
Director, Vita (Europe) Limited
Basingstoke, Hampshire RG21 7RD, UK
 
Tel 44 (0) 1256 473 177
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