>Does this mean that when I find papers that claim there is "no harm at
field relevant doses" what they are really saying is that there is harm,
but it is at some "acceptable level" that they don't define?  Is that the
point you are making?

I have seen blogs or promotional material that might say "no harm at field
relevant doses," but I'd criticize any peer reviewed paper that used that
exact wording.  What would likely be spoken of would the the NOAEL--the "no
observed adverse effects level."

And this is what Bill Truesdell is speaking of.  The residues of
clothianidin in canola nectar and pollen are indisputed and well
documented.  Yet colonies foraging on treated canola not only thrive, but
any adverse effects upon either colony strength or honey production are not
observed (not measurable).  Thus, "no observed adverse effects."

A scientist would not say "no harm," but rather that he/she could not
observe adverse effects.

And thank you Mark for explaining enzyme kinetics to the readership : )

Christina, none of us are doubting that as a general rule bees are better
off if not exposed to pesticides.  Of course there are exceptions--colonies
exposed to certain miticides will invariably fare better than those not
exposed, since the beneficial effects of those neurotoxins (the killing of
varroa mites) outweigh the adverse effects upon the bees.

My only complaint is the tunnel vision of those who are only looking at the
adverse effects of the neonics.  Even in one of the documents that you
cited, the Fraziers explained in layman's terms that the "hazard quotient"
from the synthetic pyrethroids appears to be greater than that from the
neonics.  And as Jim says, many of us observe the adverse effects of
fungicides.

That is not to say that neonics can't be problematic.  There are clearly
applications that result in excessively high and harmful residues in
nectar, pollen, or dust.  These should be better regulated.  But your
premise that any single class of insecticides is the main cause of the
problems that we see with colony health these days is simply not supported
by on-the-ground evidence.

Many of us are very well acquainted with all the studies that you are
listing.  And I'll enjoy the plotting exercise (Cresswell redux) that you
and Jim are engaged in.  All the lab studies and speculation are of great
interest.  But I travel all over the country and the world speaking to
beekeepers in agricultural areas.  Pesticides are often a problem.
However, I've yet to see compelling on-the-ground evidence that the neonics
are the prime problem facing bees.


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

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