>Randy, can you give us a cliff notes version abstract?

OK, short version:

The 600 hives belonged to 12 beekeepers from several states, but all going
to almonds.  I don't know whether the findings apply to others.

   1. Fall cluster size of 11 frames appears to be a defining tip point.
    Larger colonies lost strength November through Feb 1; smaller colonies
   gained strength (if they survived).
   2. All colonies trended toward 9-10 frame strength at the end of
   January, no matter what the starting strength in fall.  This could be
   partially due to beekeeper management during winter (feeding was allowed
   for individual colonies).
   3. Winter mortality increased linearly as fall strength decreased from
   12 frames to 5 frames (didn't analyze many colonies less than 7 frames in
   fall, none under 5 frames).
   4. There was little winter mortality of the colonies above 11 frames in
   fall.
   5. In my California group, treatment with dsRNA product targeted at IAPV
   (and secondarily ABPV and KBV) greatly reduced winter mortality.
   6. It appears to me that colonies smaller than 11 frames in fall already
   had issues.  The smaller the colony, the more likely that those issues
   would cause winter dwindling or mortality.  The positive effect of
   treatment suggests that acute viruses had strong negative effects on weak
   colonies over winter.


--
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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