> The metabolites [fed to the bees in the Suchail trial] are
> 5-hydroxyimidacloprid, olefin,
> 4,5 dihydroxyimidacloprid,
> desnitroimidacloprid,
> 6-chloronicotinic acid,
> and a derivative that they call a "urea derivative".
> (Except that it's not urea...it's still a two-ring hydrocarbon
> like imidacloprid, and it still has the benzyl position carbon
> linking the two rings. One of the rings has a urea group
> incorporated into it.)
I have to question the validity of feeding the bees various metabolites and
even a stand-ins for a metabolitie without a rock-solid understanding how
they appear in nectar and pollen and how they are presented to the bees in
nectar and pollen. I remember someone listing the "typical percentages"
found in each of nectar and pollen, and the relative toxicity of each as
compared to the Imidacloprid itself, but that may have been a slide from one
of the "CCD working group" meetings in the 2007 timeframe in either Fla or
at USDA Beltsville. Anyone have that info?
My concern is simple - what the bees harmlessly metabolize internally may
very well be "toxic" when fed. As an example, I would not survive long on a
force-fed diet containing significant amounts of human stomach acid, as it
would eat through my esophagus. Yet that exact acid does me no harm when I
create it as a response to eating various foods.
To add some reality to the mix, the test results one gets back when one
sends Imidacloprid-killed bees down to Gastonia for analysis look like:
Chemical Detected LOD
==================== ========== =======
Imidacloprid 19.3 ppb 1.0 ppb
Imidacloprid 5-hydroxy None 5.0
Imidacloprid olefin 35.2 10.0
These were freshly-collected dead bees from hives that were hit with a
serious kill. Someone's Grandmother bought a bottle of concentrated
Imidacloprid, and apparently did a ground drench with the undiluted liquid
on her prize roses in Brooklyn last summer. Serious impact on about a dozen
hives resulted, with foragers dying over a period of two weeks as the rains
recharged the nectar supply. Everything else was done blooming by then, so
it had to be ornamentals.
But look at the numbers... The lab only bothers to test for 2 metabolites
and the unmetabolized pesticide itself. And the numbers for the other two
were very high, yet the 5-hydroxy reading was less than 5 ppb max. This
means that we don't understand actual metabolism at all until we look at a
whole bunch of readings from bees that were killed in pesticide kills, and
see what they ended up with post-mortem. Did they die so quickly that they
had no chance to break down the pesticide into 5-hydroxy? Or does massive
overdose cause a dysentery-like symptom where the bee passes all the
5-hydroxy out of their bodies before dying? In cases of less drastic
over-dose, the dead bees have detectable levels of all 3, which is why the
lab tests for all 3.
> All of the trials showed about the same mortality...a surprise.
> Mortality began after 72 hours in each trial and maximum mortality
> in all trials at 250 hours was about 60%. The controls did not have
> mortality above 15% over that time (stated but not shown).
This tends to tell the astute observer that the experimenter killed the bees
with his or her methodology, rather than with the substances under study.
For all the metabolites to start to kill bees at the same time, and end up
with similar maximum kill rates seems highly unlikely, as it is
generally-known that metabolites are far more toxic than others. We
beekeepers do not need to worry about unpronounceable chemical names, we
need to simply look for results that show a reasonable connection between
dose and effect, and a connection between relative toxicity and effect.
For baseball fans, we should mark our scorecards with a backwards "K" for
Suchail.
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