Hello Jim & All,
Jim I do not have all the answers to our problems. Wish I did but will 
provide what I have learned.

> I tested hives for varroa and nosema in Aug of last year.  Tests were 
> clean, low mite counts of 2-3 mites, low tm counts and no nosema.

No nosema?

 The problem in larger operations in my opinion is random testing.

The recommendations from Spain shows  that if you find nosema ceranae spores 
then you should treat. Regardless of spore counts. I don't want to step into 
an area my friend Randy Oliver is working on in his tests but what I was 
told.

> Lost most of those hives, which when tested as deadouts had in excess of 
> 16 million nosema spores per bee...

My opinion is you missed the fact you had nosema in the fall. Research done 
in Spain has shown that even nosema ceranae takes a period of time to kill 
the hive. However only symptoms can be beekeeper detected in the last two 
months (other than by microscope spore count).

Faster crashes occur in my opinion when heavy nosema spore contamination is 
on comb.

recommendation:
I would treat the dead out comb with acetic acid before reinstalling bees.

Sincerely,
Bob Harrison 

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