> And what does it matter to bees if a corn plant contains neonics--the only
part that they eat is the pollen.  

So, Randy, and who will eat that pollen? Right, for most the larvae! Do you
know that the recognition procedures for neonics by Bayer - certainly in
Europe - didn't even foreseen in tests on larvae? 

> A definitive survey recently conducted across the Corn Belt and Canada
demonstrates that bees are exposed to only very low levels of clothianidin
in either corn pollen, or canola pollen and nectar.

And yet! Please read this extract from the very recent EFSA analyze:

2.2.6. Conclusion on the risk via systemic translocation in plants -
residues in nectar and pollen (including sublethal effects)
A low risk was concluded for a number of crops, which are not foraged for
pollen or nectar by bees (see a list of these crops in Table 8, above).
However, imidacloprid is authorised for use on seven bee attractive crops.
Essential information (levels of residues in nectar and pollen) was missing
for risk
assessments, therefore a data gap was identified for further assessments to
address the risk (i.e. the acute risk and the long-term risk to colony
survival and development, including the risk to bee brood, and the risk
following exposure to sublethal doses) for asparagus, pumpkin and linseed.
For maize, oilseed rape, sunflower and cotton, first-tier risk assessments
for the EU authorised uses were conducted. The ETR values for acute exposure
of adult bees were between 0.37 and 1.93 for oilseed rape, sunflower and
cotton. This means that the calculated intake is close to or above the oral
LD50 value (an ETR of 1 would show that they are equal), therefore a data
gap was identified for these three crops. In case of maize the ETR values
were between 0.01 and 0.05, indicating a margin of safety.
Therefore these calculations indicated a potential acute risk, at least for
oilseed rape, sunflower and cotton (for information: the acute NOEC based on
mortality is about 3 times lower than the LD50). It must be borne in mind
that the residue intake estimations represent worst case scenarios. Further
higher tier refinements might be performed. For example, data on metabolism
in bees, dilution factors, or specific sugar content for the crops could be
considered, but no agreed approaches are currently available. It should also
be noted that the highest available residue levels were used for the intake
estimations. This was clearly worst case for sunflower nectar.
Chronic risk assessments, where the calculated residue levels in the feed of
the bees were compared with the NOEC value of an available dietary test,
were also conducted for the same crops. This indicated a margin of safety
between 2.9 - 10.6 for these four crops. However, it is noted that these
assessments were only conducted for illustrative purposes and should not be
considered as a definitive risk assessment.
Similar assessments were conducted with a slightly lower sublethal chronic
endpoint, where effects on foraging were observed, but there was no impact
on colony development. The margin of safety ranged between 2.4 - 8.8 for
these four attractive crops.
Again, these calculations were based on worst case approaches and the
toxicity endpoints are also uncertain since currently no harmonised or
internationally recognised test guidelines are available for chronic
toxicity (either for lethal or sublethal effects).
Since no reliable endpoint was available for brood, a data gap for risk
assessments for bee brood was identified for the attractive crops (see Table
8).
Higher tier (semi-field and field) studies were available for oilseed rape
and sunflower (likely the most attractive field crops to bees). All of these
studies had drawbacks (see section 2.2.5, above), and therefore they were
not sufficient to demonstrate that the risk to bees was low for the use of
imidacloprid as a seed treatment in oilseed rape or sunflower.


Kind regards,

Ghislain De Roeck,
Belgium. 2.2.6. Conclusion on the risk via systemic translocation in plants
- residues in nectar and pollen (including sublethal effects)
A low risk was concluded for a number of crops, which are not foraged for
pollen or nectar by bees (see a list of these crops in Table 8, above).
However, imidacloprid is authorised for use on seven bee attractive crops.
Essential information (levels of residues in nectar and pollen) was missing
for risk

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