A lot of intriguing comments and observations, but a great synthesis  
still seems elusive.  There seem to be too many variables for a clear  
picture.  A high rate of mite growth in individual colonies is still  
necessary to propel the problem.  Theoretically (yes, theoretically)  
the problem would not exist if the majority of colonies kept mite  
numbers low or decreased them through active resistance mechanisms  
that can take care of invasions as they happen.

Randy, I do not know of anyone measuring drift between colonies when  
evaluating for mite growth in standardized tests.  The specific test  
that I alluded to with queens from "survivor" colonies was actually  
the first use of an apiary inside a more or less abandoned forestry  
experimental plot with mid-sized pecan trees with brush and  
undergrowth.  Lanes were mowed along rows of trees and staggered and  
irregular inlets were cut into the brush from those lanes.  Colonies  
were placed singly inside those bays to "minimize drift".

Emphasizing prior anecdotal observations that suggest that the effects  
of drift are small compared to growth of mite populations within  
colonies: colonies with highly resistant queens can keep mite levels  
low or undetectable while in yards with large highly susceptible  
colonies in the mix.  Concurrent with these observations are  
quantifications that show that the first remove high proportions of  
infested brood, while the latter barely touch infested cells. 
       

             ***********************************************
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