It is useful to distinguish immediate from subsequent causes, and ask about 
 multiple causes, causal hierarchies, and causal trains.
 
The actual cause of death may be overwhelming viral infection,  but mites 
acting as vectors and damaging the bee fabric are  clearly joint causal 
factors.
 
Again the resistance or tolerance offered by different races, strains  and 
individual bloodlines clearly makes a difference.  So this too is  a causal 
factor, in that cause of failure may ultimately be identified as lack  of 
resistance.  
 
Inasmuch as treatments disturb the acquisition of resistance, they too are  
causal factors.
 
None of this is to say there is no connection between varroa and CCD; just  
that indentifying that as a sole or even main cause is problematic.
 
Mike Bispham
 
 


             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Access BEE-L directly at:
http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A0=BEE-L