Blane White wrote:

>The drone brood trapping methods have been researched and have been shown to be >effective.  They are labor and time intensive but do actually work.  The letter in ABJ >pointed this out but raised the issue of if this is a type of selection of the varroa >population that we want to do.  Another concern is the lack of mature drones from these >colonies for mating with queens.  If you destroy all your selected drones to control >varroa, don't expect to be able to make very much progress breeding for those traits in >your own bees.

The key to the selection hypothesis is "if you destroy all of the drone
cells" and also seems to assume that the mite level is still high after
drone removal which would force selection for worker cells.

The drone trapping method relies on a frame or more of drone foundation
to trap varroa.  Any inspection of the other frames in a hive will show
many drone cells in each frame, so it is nearly impossible to destroy
all the drones. What is happening is a reduction of the mite level when
the frame(s) of drone brood is removed. So you have a reduced mite
level, but still plenty of drone cells for that reduced mite level,
hence, there is little or no selection for worker cells. The hotel
always has enough of the right size rooms.

The drone trapping method has not shown a shortage of drones for queen
mating. In essence, you are running an eight or nine frame hive instead
of a ten frame hive, which some beekeepers do as a matter of practice.

One other problem with the assumption. A "normal" hive has no drone
trapping frames. With "limited" drone cells, you would think that we
already would select for worker cells, based on the numbers of varroa
found in a hive compared to the number of drone cells. It does not
appear that this is happening, but it should, if the assumption that you
can select for worker cells by removing drone brood is correct.

Bill Truesdell
Bath, ME