James,
May I state that I am in full support with the points put forward by Bob relating to the probable source of V.d. in the
British Isles - they came from a population that most probably had been in contact with pyrethoid agents for several years
already.
Having arrived and "settled" the advised treatment was sensible - but no one should be surprised about the relatively rapid
appearance of resistance, as mentioned, their antecedents had already been doused - possibly with legal and illegal treatment
methods.

So, what to do now - follow official lines based on the same chemical family?
It will work until it stops working - fine! - if that is to be accepted
But if beekeepers realise that this is a for a relatively limited period of time and they will possibly loose their colonies
many will resort to homemade techniques - just like in the rest of the world.

This will be made even more likely if there is no alternative alternating treatment put in place NOW!

British beekeepers must take the chance, get a second unrelated treatment method officially recognised as soon as possible to
limit the spread of cardboard dipped in Amitraz etc.

The pathway is already written as found in the reports filed in other countries.

At the same time: really push for a genuine and extensive program of trying to create naturally resistant bees - there is a
fair choice to investigate and more importantly to add to.

Get that project well known in the beekeeping world, and get the beekeepers involved.
Let others know what is happening - success or failure - just ensure that knowledge is passed on and not kept in the shelves
of research establishments. We beekeepers and researchers need each other!

Peter

P.S. Thanks Medwin for your comments!