Rimantus Zujus wrote:

"Does it mean that the mite resistance to Apiguard will develop about 7
times
sooner than to Apistan, having a much higher efficiency? Your opinion,
please."

I suspect it will take a lot longer for varroa to develop resistance to
thymol because a) the selection pressure on the mites is lower [than for
pyrethroids, for example] as thymol is not so widely or often used -  and b)
thymol has a more devastating and general action as opposed to affecting a
specific neurological site. I believe it would be more difficult for mites
to overcome breakdown of cell walls and proteins, as thymol is purported to
do, rather than modify one nerve site or develop a detoxification process of
a particular agent.

If thymol were over-used resistance might be more likely to develop,
eventually. IPM is the answer.

This is my opinion only; maybe in a few years we'll have a clearer answer. A
programme of varroa resistance monitoring in Europe, especially the
potential for resistance to thymol is being undertaken by Vita (Europe)
Limited. I'll report our findings in due course.


Max




Dr Max Watkins
Vita (Europe) Limited
21/23 Wote Street
Basingstoke
Hampshire RG21 7NE
UK

Tel.: +44 (0) 1256 473177
Fax: +44 (0) 1256 473179

e-mail: [log in to unmask]

web: http://www.vita-europe.com

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