Eric,
 
    Having your bees down to two supers for winter prep, I would not
    recommend 4 strips of Apistan in the top super.  I think 4 strips would
    not give you anymore varroa control than just two.  You could get away
    very well with placing two strips in the top super (appropriately spaced
    in the cluster). Why?
 
    Although the colony will be very crowded during this fall application, a
    fair number of bees will vacate the hive over the course of the 45 day
    treatment.  The temperature regime in Alberta at this time still ensures
    considerable bee activity inside the hive, ensuring good dispersal and
    distribution of the fluvalinate during the application period.  At the
    same time, brood will dwindle rapidly and by the time you are ready to
    pull the strips out (I trust you are one of those conscientious
    operators that does NOT leave the strips in all winter!), the little bit
    of brood that is still there if any, is in the top super anyhow.
 
    Paul van Westendorp                         [log in to unmask]
    Provincial Apiarist
    British Columbia