Lloyd Spear wrote:
"As to how effective it is in controlling Varroa, do the math.  Assume 80%
of
foundress mites (females reproducing) choose drone brood and those that do
produce 3 daughters.  Assume the other 20% are in worker brood and produce
1.5 daughters.  Work out the numbers (separately) over 120 days."

This is a very interesting calculation that i have been thinking about doing
but never gotten around to it. At least one parameter is missing, though.
How often is one new generation of mites born? You also need to estimate how
many percent of the total drone brood that one removed frame is. I'm sure
this calculation has been done before. I just haven't seen it anywhere. Does
anyone have it?

I remove drone brood too, but in a slightly different way: When the first
flow starts, a frame with a vertical divider in the middle (no foundation)
is inserted in the outer part of the cluster. Ten days later, the bees will
have build drone comb in the frames. I cut out one half. Another ten days
later, i return and the bees will again have build drone comb in the part i
cut out earlier. The half i saved will now be filled with capped drone
brood. I cut this out and bring the wax home to freeze it. I continue this
in ten day cycles for as long as the bees will build drone comb.

Good things about this method:
-the drone frame becomes a good status indication of the colony:
1. if the colony has swarm cells, a few of them will usually be found on the
drone frame
2. building comb reduces swarm tendencies (this could be a myth)
3. if they don't build any comb, the colony is weak

Not so good things about this method:
1. You have to cut out the drone brood on time, if you slip a few days and
the drones start hatching, you get the opposite effect. You're a mite
breeder
2. You end up with lots of drone brood! Don't even think about melting it in
a solar wax melter. Some suggest burning it and i tried that, but it wasn't
quite as flammable as one would want.

/Mats Andersson, Stockholm Sweden