Do hygienic bees get afb, or can they remove dead larvae before spores have developed
Disease is very complex. It cannot be removed with dead larvae. Before that frames have more or less spores even if you do not know it without laboratory tests.
In NZ ABF book it is said that last year honey in super combs is the most common way to spread disease in the apiary.
That is why first thing to prevent spreading the disease is to keep own furniture and frames to each hive, and do not mix them between all hives.
But it depends on situation, do you have that disease., we can send an example to laboratory and seek an answer, that does my honey mixture has spores. It does not make sense that you do not have spores, but you nurse hives like they are going to die all the time.
Like Jesus said 2000 years ago: Only sick ones needs cure.
But the disease can hide 2 years before you see a tiny hole in brood capping. After that it spreads in a month that the whole brood space seems to rotten.
I think that British ABF policy is very good, because your hive density is big. Disease spreads quite easily by robbing. All kind of open open feeding is bad. It invents robbers from long distance.
My experince is too that sun melter is very bad, if bees have acces to melted combs. Spores need over 130C temp to die, and sun melter has only about 60C temp and carbage can have what ever diseases.
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What ever you do out there, it is not bad , if British beekeepers know the facts, and do not generate their own " I do not know but" knowledge about things, which are serious. And I do not understand those village dog's poking with ha ha ha , when when handle disease issues on forum. It is same with varroa. It is not ha ha thing.