HI Everyone,
Interesting post explaining what you did and why Tim.  I do have one issue which has already been raised by Rich.  Your brood disease problem may not have been foulbrood ( American foulbrood,  AFB ) but due to the high levels of varroa and associated virus infections.  I have seen this several times where at first look it appears to be AFB but closer inspection indicates that it is not.  Not sure what exactly is going on but once the mite population is reduced the condition clears up with or without antibiotic treatment.  You observed 1/3 rd of the brood effected and this is well within my observations of brood damage due to high varroa populations.  A shortage of pollen and nectar or honey stores also contributes to this condition at times but again if the varroa problem is dealt with the colonies usually turn around nicely.  If they are starving of course you also need to feed them.  As Tim observed heavy mite pressure on the bees causes stress and other factors that wouldn't usually cause visible problems shows up.  Now if the brood condition you saw was due to the varroa/virus problem there is no AFB scale for the colonies to deal with or to cause later breakdown.

FWIW

blane



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Blane White
MN Dept of Agriculture
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