> >The second part: removing diseased brood combs is not really breeding for
resistance.  Breeding for resistance would entail not propagating any colony
that has disease, and raising queens from colonies that do not show any
symptoms of disease. In our experiments we found that even some hygienic
colonies came down with clinical symptoms of AFB after we challenged them by
putting combs with AFB scale in the colonies.  But most of these colonies
recovered on their own, without chemical treatment, or removing combs.  They
simply were able to remove the diseased brood from the combs, but it took a
few weeks to "get a handle" on it all. < <

I think this is not contrary to what anyone here has been saying.

There may be differing conclusions about what this means, though, depending
on each individual beekeeper's expertise, environment, bee stock, medication
practices, age of equipment, availability of drawn comb, appraisal of the
ambient disease levels, etc.

As for removing combs, there are several reasons that removal makes sense,
even if the beekeeper believes that the bees can clean up the remainder --
either because of having requeened with a HYG queen or other reasons, such
as having added a drug or supplementary feed.

Removal is advisable in most cases to eliminate the most obvious part of the
spore load, to enable the bees to work on clean comb -- scaly comb is hard
on small hives in marginal weather and actually repellent.

Moreover, even if HYG or partially HYG stock is in use, there are better
ways to test and maintain the trait than having breakdown in the hives and
there is always the chance that an individual queen may not carry the trait
or that a supercedure queen may open mate and break down.

allen
http://www.internode.net/honeybee/diary/