> >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/