As wisely pointed out by Aaron, using frames with drone foundation
only works well when a frame filled with sealed cells is immediately
replaced with another.  I should have mentioned that.

Drone cells are capped for 18 days (compared to 15 days for workers).
This not only means that Varroa can sometimes produce three
generations therein (compared to two fgenerations on worker larval)
but also means that the beekeeper has a great day of latitude
concerning visiting the hive to pull the frame.  I find that if I
return to the hive anywhere from 25-30 days after I was last there
that I will find a full frame of capped larvae.  Some are within 1-3
days of emerging, and some would not emerge for a week.  But all are
capped and many Varroa are destroyed.

There seems no question, in the research community, that Varroa prefer
drone brood.  But how do they find it?  Some researchers think that
Varroa can detect drone brood by phermones.  Others say that is
nonsense, and point out that drone larval are fed for a full day
longer than workers and think that more drone larval have Varroa (than
compared to worker larval) only because of the higher number of worker
visits.  Regardless, by freezing one rids the hive of THREE
generations Varroa.  Repeat that by 3-4 times, and the numbers really
add up.

I have also noticed, and this surprises me, that when the bees have
drone foundation they will produce drones right up until frost.  I run
my hives with almost-new worker foundation (none more than 5-years
old) so don't have a lot of natural drone cells around.  But before I
started using drone foundation I never noticed sealed drone cells so
late in the year.

My yards have 25-30 hives each.  If I had to make two trips, one to
pull drone foundation and another to replace it, the labor required
would not work.  As it is, when I leave in the morning I pull about 30
frames from the freezer (which holds about 60 frames), and they are
still frozen when I put them in the hives.  It astounds me that in 48
hours these frames are clean and ready for the queen; in 24 hours they
are 'mostly' clean.

Sure, one could just destroy the sealed cells and immediately return
the frame to the bees.  A simple puncture with a fork would do the
job.  But that would take perhaps a minute each frame...I am always in
a hurry when I am in a yard, and would not like to add a 1/2 hour to
my jobs.  But perhaps I am wrong about that.

--
Lloyd Spear
Owner Ross Rounds, Inc.
Manufacture of equipment for round comb honey sections,
Sundance Pollen Traps, and producer of Sundance custom labels.
Contact your dealer or www.RossRounds.com

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