Lloyd Spear wrote:
 
" ... if we eliminate drone brood in an attempt to control mites, the
  effect will be to put the mites onto worker brood and the hives will
  collapse sooner rather than later."
 
I respectfully disagree.  With the drone trapping method, entire frames
of drone brood are removed along with the population of varroa infesting
the drone brood.  Timed properly, at the time in the season when there
are ample drone pupae to attract the majority of varroa mites, removing
the infested drone brood will keep the varroa population in check such
that they stay at low enough levels to keep them from infesting worker
brood.  Removing the varroa along with drone brood leaves few mites
remaining in the hive to get into worker brood.  Hives won't collapse
sooner, varroa populations will be kept in check throughout the honey
production season and when drone brood is no longer present due to
seasonal flux, the varroa population won't have reached the levels
needed to bring down a hive in the time remaining before honey supers
are pulled and chemical treatments are used.
 
Unfortunately the time to remove drone brood is also the time that
queen breeders want copious numbers of drones in their populations and
the drone trapping method is counter to that goal.  I don't see any
way to compromise these two goals.  It seems that drone trapping isn't
a productive option for queen breeders.  My suggestion would be to
segregate different classes of hives: those used for honey production
and those used for drone production.  The honey producers can employ the
drone trapping methodology; the drone producers can be treated with
chemicals, forsaking the honey produced in those hives.
 
It might even be possible to move the trapped drones from the honey
producers into the drone producing hives rather than freezing them or
feeding them to the chickens (as is recommended in the drone trapping
method).  This will allow the drones to emerge (although their varroa
infested value may be minimal) and the drone producing hive may become
one hell of a varroa haven.  Furthermore the infested drones would most
likely end up drifting back to the honey producers bringing the varroa
infestation back to the hives one has worked so hard to keep varroa
levels in check.  Perhaps this speaks for segregated yards rather than
segregated hives.  Another problem may be the effects that chemical
treatments may have on drone verility (currently under study).
 
But I don't know, perhaps the demographics of varroa populations would
work differently in the field than they do in my head.  Lots of things
work differently in the real world than they do in my head!
 
Aaron Morris - thinking better answers lie in better investigations!