David Eyre wrote:
 
>This is my big concern. We 'don't got' Varroa either. :-}}
      >  I am hoping that before it arrives I will have arrived at an
acceptable
>control method. As a Queen breeder, I am totally confused. On one hand I
>desperately need to breed drones to mate with the queens I raise, but on
>the other hand I will be raising Varroa. Honey is not a major concern, but
we do get some, which precludes the frequent use of Apistan. Also there are
>now concerns that Apistan will weaken the hive.
      >  Formic Acid is accepted here in Canada but that stuff will take
your skin
>off!  Essential oil might be the silver bullet, but here again there are
>legal concerns.
 
If concerns about  residues in honey prevent the use of Apistan whilst
supers on the hive this should surely also apply to use of essential oils
and formic acid at this time, quite apart from the concerns about efficacy
and safety of these substances when used as varroa treatments.
 
Of course, I don't know the details or scale of your queen rearing
programme, but it seems to me that a solution would be to maintain one or
more drone colonies per apiary specifically for drone production. These
would be strong colonies headed with good queens kept in several brood
chambers with an abundance of drone combs but without supers.
 
You could treat these (e.g with Apistan) during the honey flow, if their
level of varroa infestation was getting out of hand due to the abundance of
drone brood, without breaking any regulations.
 
Towards the end of the season they might be useful in the apiary as a
source of combs of brood and honey for nucs etc.
 
James Morton
CSL National Bee Unit, UK