On Thu, Apr 25, 2013 at 10:51 PM, Peter L Borst <[log in to unmask]>wrote:

> Regarding treatment of citrus: My friend Jody Johnson studied IMI
> (imidacloprid) treated maple trees
>

That is an interesting study.  How was the treatment applied?  Do you know
at what rate?


> >Of the 108 water samples collected, 9 samples ranged from 7-131ppb
> (LD50=280ppb), and 14 samples were at the limit of detection by ELISA
> assay.


Who did the ELISA assay?  I recently asked on this list and got only one
suggestion and when I contacted that lab they did not do ELISA testing for
pesticides.  They suggested two other labs, but both of those were also
dead end leads.


> The red maple study revealed ranges of IMI in plant tissue of 0-53,300 ppb
> in leaves, 0-5440 ppb flowers, 0-32 ppb pollen, and 0 ppb in nectar,
> supporting evidence of predominantly xylem transport.
>

The leaf numbers above don't seem to relate to the number below


> > The results we found suggest that IMI is not a risk to honey bees
> through the pollen of red maples but the high concentration of IMI in red
> maple leaves may raise a different issue to honey bees. The concentrations
> of IMI at levels on the order of 103 ppb in leaves could be an exposure
> risk to honey bees if the concentrations were released from the leaves. One
> scenario for exposure is through the decomposition of leaves in pooled
> water that is visited by honey bees.
>

??The highest rate is way over the 103 ppb in leaves.  Was 103 the average?
Similarly, 32 ppb in pollen is a lot, wonder what the average was.  In
sunflowers in France it was rarely over 8 ppb.  In canola it is usually
below 6 I think.


> Josephine Johnson. (2012)  The role of pesticides on honey bee health and
> hive maintenance with an emphasis on the neonicotinoid, imidacloprid. PhD
> Dissertation
>

Was this ever published as part of a paper, or is it only available from
Ms. Johnson?

Stan

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