Re: How to diagnose for ailments that affect bees (early stages)
Micha, if I may. I would suggest that a through understanding of the Pests and Diseases of Honeybees is a good place to start. There is such a book available which I think every beekeeper should have on their book shelf, as a reference. Maybe at their bedside as a sleep aid. Chuckle, chuckle.
Knowledge is our best weapon against the diseases and pests that effect our bees.
Keeping healthy bees is a good preventitive method. I do not treat propholactycally (sp?) for diseases and pests. I don't dust for AFB, I burn what I identify as AFB. I do take measures to knock down mite loads, in reaction to their presence. I have never treated for Nosema, perhaps to my detriment. But, unless one treats for Nosema because it might be there, operative words being "might be", how does one know except after finding it.
So, I guess what I am saying is, that my advice on how to handle potential pests and diseases of honeybes, is that one learn all one can absorb, keep healthy hives by managing the problems one comes across (treatments/medications/control methods/integrated pest management are all managment tools), react to what one finds, not what may come down the pike and then you will be alright.
That's how I see it. Any advice you may take from the above is worth what you paid for it.
Mark Berninghausen "To float, upheld, as salt water would hold you, once you dared." Denise Levertov, poet