> Not that I'm not suspicious about neonics.  The evidence for effects on
> bumble bees at low levels seems to be more compelling.  Or am I wrong there?
>

No you are not. That caused me concern when I first read about Imid and its
use in green houses. From all I see, the difference is in seed treatment
compared to drench, soil injected or spray which are more likely for
bumblebees (and honeybees on crops other than corn and canola) to
encounter. Drench is used in greenhouses so pollinators (bumblebees) in
green houses are subject to much greater concentrations in nectar and
pollen than honeybees on canola..

Also classic is tree treatments where drenching is the preferred method.
There are records of dead bumblebees around such treated trees.

But it is not just the neonics that cause such problems, as shown in France
and fipronil, which is much more toxic to bees. Most insecticides applied
by drench act like systemics, even though the manufacturer says they are
not (see fipronil).

I had an interesting time reading about drench application compared to seed
treatments. The obvious result is, that because there is more pesticide
used in drench, there is a greater kill than seed treatments. So one other
reason for bees doing well on canola is there just is not that much
pesticide getting to the pests as well as the bee. There is enough to
control the pest, but not over-kill it, compared to drench or soil
injected.

My bet is, that if the neonics were drench applied, there would be a
problem in Canola. Stan's experience mirrors that- he had problems with
Imid until the local farmers shifted to seed treatments.That is backed up
in US studies that looked at drench and squash, where much greater amounts
of pesticides were found in pollen and nectar than seed treatments.

Fipronil did a great job on the bees in France- and it now on the EU list
of "let's ban another one", but in this case, they are right. It does kill
bees. Will be interesting to see if it makes it, since it is used on golf
courses, which have a much stronger lobbing group than farmers. However,
the stuff waiting in the wings will not improve the situation.

Bill Truesdell
Bath, Maine

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