Thank you Juanse for the studies.
Very interesting the differences in the results--perhaps due to the sandy
soil in the East???
Or was it the type of application?

I feel that Stan's points are important.  IMHO, the highest and best use of
neonics are as seed treatment, since only a low level of the insecticide is
used per acre.  I am uneasy about drenches, chemigation, foliar sprays, etc.

Re uptake and concentration, I also find what data I've seen to be
conflicting.  Sunflowers appear to concentrate the insecticide.

What are needed are studies that collect pollen and nectar from the variety
of weeds and native plants that invade or grow adjacent to treated fields.
 Krupke's recent data suggest that bees may find patches of flowers with
high levels.  There will soon be extensive data released, but don't know
how much it will be broken down by pollen species.

I'd be most concerned with levels in pollen, since foragers appear to be
able to detect high concentrations in nectar, and find them repellent.
 Luckily, pollen may be "diluted" in the hive.  When I've taken cores of
beebread from my own hives, it is layered with different colors.  This
trait may work to reduce the overall concentration of the residues.  Oddly,
in the case of clothianidin, it appears to be virtually nontoxic to bee
larvae!  So any toxicity would likely be more of an issue for the nurse
bees, who are the major pollen consumers.

As an aside, I'm surprised by the low number of responses that I've gotten
off list from Midwestern beekeepers when I asked about their experiences
with colony health in corn, soy, and canola.  So far, all that I've heard
were from beekeepers who say that they are surrounded by these treated
crops, yet had zero or close to zero mortality this winter.  Others?


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

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