Hi Michael and All:
>I've requeened lots of chalky colonies.
>Sometimes it works, but not very often.
That is my experience as well. I think that if you wait until the situation
is quite severe that the break in brood rearing is not matched by the worker
population which is also decreasing. I think it may be better just to unite
the colony with a better one. I have also begun to think that broodcombs
with a lot of chalkbrood (especially with the black spore laden mummies) are
best destroyed or taken back to the rib and disinfected if they are plastic.
This year I went from 200 to 400 colonies. I had the least chalkbrood I
have had in years due to a combination of putting honey combs in new brood
supers and one of the warmest springs I can recall. The combination of
rapid spring buildup and cold nights seems to trigger it.
But I agree that breeding hygienic bees is the answer.
Regards, Stan