The letter to the ABJ was fairly non-specific, but what I understand him to
be referring to is the phenomenon of continually selecting for survivor
mites from worker brood. Assumming all drone brood mites are killed, Then
each generation of mites would, presumably, be better able to reproduce in
worker brood, as all survivors have the traits that enable this behavior.
Since not all mites can reproduce in worker brood, there is a strong chance
that the traits needed to do so are recessive (otherwise, the majority of
mites could do so). Keeping a large number of drone-produced mites on hand
would presumably suppress the traits needed to reproduce in small cells.

If you somehow managed to breed a mite that easily reproduced in worker
cells, then this mite would, presumably, be better able to adapt to breeding
in 4.9 foundation.  That assumption of perfect kill of drone produced mites
is quite a large one, however.

You could end up with a small population of weak mites (stunted due to
forced reproduction in worker cells), although not likely. This might let
you drop chemical treatment. However, you would have to keep removing the
drone brood on a regular basis, including any drone brood laid on non-bait
comb.

It is equally possible that you could completely eliminate varroa from your
hives after a faily short time period, if you had 100% SMR bees -- forcing
all reproduction to be done in drone cells, which you are removing.  If you
could remain isolated after that (note, there is NO chance of that in this
part of the US), you could then cease treating, so long as you never
imported any new bees and swarms never reached your area.

Personally, it seems that the use of drone comb continously in the brood
area is just asking for trouble. You are increasing the percentage of drone
brood in the hive, which dramatically increases the number of mites able to
reproduce at any one time. Only if you pull that comb every few days, never
missing due to weather, illness, work schedule or a vacation will you kill
those mites -- which might not otherwise have even been in the hive at all.
You still get mite reproduction in drone cells mixed in with other frames of
brood. Occasional use, as a means of diagnosing infection rates, is another
matter entirely.

K. Oland

-----Original Message-----
From: Bob & Liz

the theory of creating a mite which only prefers worker brood to be small as
all research points to varroa loves drone brood and worker brood is a second
choice.