Another request for information:
 
Does anyone out in Bee-L world have information on the effects of
Varroa or trachael mites on the availability of pollination services,
numbers of hives available for pollination, effects on crop yields,
and so on.
 
Even non-published, anecdotal  information would be helpful, or
even impressions.
 
Thanks, Peter Kevan, U of Guelph, Ontario, Canada