James Fischer wrote:
>Well, what IS present in the raw material?
>
>Plants break down Imadocloprid when they metabolize it,
Actually, imidacloprid is fairly stable in plants. That is why
it is good as a systemic pesticide. It persists through the season
and offers long term insect toxicity. When testing is done of crops
to make sure they are below the maximum residue level, they do not
bother to test the metabolites. What is of more significance in plants
is not metabolism or breakdown, but the transport of imidacloprid to
various plant parts. I am not aware of what has been done in corn, but
in sunflowers the chemical is found in fairly high concentration in the
leaves, but also is found in the flower parts, and then in even higher
amounts in the seed. If corn is the same then one would expect that
the seed (which is the part used for the syrup I presume) would have
a high concentration.
1.2 (Ref. 5: BAYER AG, Doc. SXR/ Am 006, Sept. 1999: Residue levels of
Imidacloprid and Imidacloprid Metabolites in Nectar, Blossoms and Pollen of
Sunflowers Cultivated in Soils with Differing Imidacloprid Residue Levels
and Effects of These Residues on Foraging Honeybees - Farmland "Hofchen" -
41 pages.)
>bees seem to take those metabolites (as found in netar and pollen)
>and further break them down.
There are two metabolites which are of concern because they are also highly
toxic to bees, those are olefin and di-hydroxy-imidacloprid. But they are
unlikely to be present at higher levels than the parent molecule, so a
simple test for the parent molecule would be sufficient. Since bees are
not being tested, metabolism in the bee is not of concern.
At present, there is a need to
>track down the specific chemical process is both in the plant
>and in the bee, so we know what to look for when doing things
>like "testing HFCS".
I do not see why we need to know the mechanics of the process in the plant
to test the level in the corn raw material. That is why a maximum residue
level has been set for corn. And the bee is immaterial.
>The post-harvest processing of corn into HFCS is clearly a
>special case, so the chemical processes there are also
>complex enough to require a bio-chemist or three to deterimine
>what the end products and byproducts would be.
Yes, I agree that the chemical processes, expecially the ion exchange,
may hopefully eliminate the chemical. I certainly hope so, because I
fed over 50 tonne last year. But I don't need three bio-chemists to
theorize about the end products. I would be happy just to have a test
for the parent molecule (and perhaps those two known toxic metabolites).
1.5. (Ref.8 : Dr. J.M. Bonmatin and Dr.I. Moineau -CNRS Orléans / Dr. M.
Colin - INRA Avignon / Dr. C. Fléché - AFSSA Nice: Rapport No. 3 of June
2000 " Effets des produits phytosanitaires sur les abeilles - Progr. 1999 -
2000"
Regarding sunflowers treated with GAUCHO:
* Imidacloprid is present in all parts of the sunflower plant.
* The concentration of the Imidacloprid in the apical part increases
significantly during the formation of the flower bud, to attain an average
of 5 - 6 ppb. at the beginning of the flowering stage (stage 65).
Regarding maize plants that have been treated with GAUCHO:
* Maize treated with GAUCHO contains Imidacloprid in all parts of the plant,
notably in the panicule visited by the bee, levels up to 10 ppb. (average =
3.8 ppb.)
* The high concentrations in the flowering parts (up to 20 ppb., average =
10.7 ppb.) suggests similarity to the phenomena observed in sunflowers (
M.F. Laurent - see 1.4.)
* (Work done in 1999 by J.M. Cantin, under the direction of Dr. M. Colin -
INRA Avignon)
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