Hello Dave Fischer. & All,

I am thrilled that a Bayer rep and a commercial beekeeper can discuss the 
issues in a beekeeping forum.
BEE=L is considered the forum the worlds English speaking beekeepers read 
( and post) and of late posts are in the archives in many languages.


Dave Fischer said:
But what about the “Italian study” which showed bees didn’t return to the
hive when feeding on syrup containing imidacloprid?  I assume Bob means the
study of Bortolotti et al. (Bull. of Insectology 56(1):63-67, 2003).

I can hardly believe you would offer this study as proof of imidacloprid not 
having effects on bees. This study was actually done in Florida privately 
with controls to confirm the Italian results. Although the study in Florida 
was primative and done by beekeepers many of the bees fed the 100 PPB syrup 
did not return to the hive.

Dave said:
  With this
perspective, the finding by Bortolotti et al. that bees don’t return to the
hive when exposed to 500 and 1000 ppb is hardly a surprise.  Nor does it
support a conclusion that use of neonics will cause a problem.

First let me say we are talking parts per billion and NOT parts per million. 
Big difference!

This study is so simple a cave man could do it! ( saying taken from the 
geico TV add).

A chemistry teacher made the solutions and foragers were marked at the 
entrance.

Bortolotti study:
 Bortolotti  simply added three amounts of imidacloprid to sucrose. Not 
rocket science. he could have added imidacloprid to nectar and still would 
be the same.

Bees fed the 500-1000 parts per billion of imidacloprid in sucrose solution 
DISAPPEARED ALL TOGETHER.  failed to return. Adult bees gone. Dave Fischer 
does not dispute the Bortolotti findings as to a 500-1000 PPB solution..

  No bees at the hive with shakes as Jim F. has suggested before as a true 
neonicotinoid kill.

The bees fed the 100 ppb did not show shakes either in Florida when they 
returned to the hive 24 hours later *if* they returned at all.


Adult bees gone.with both the 500 and 1000 Parts per billion amounts .

Then we get to the lowest amount of imidacloprid fed by Bortolotti in 
sucrose solution. 100 parts per billion . Bees fed the 100 parts per billion 
did return to the hive but only after 24 hours. Researchers I have spoke 
with (other than Bayer) seem to think 100 parts be billion is a very light 
dose of the neonicotinoid.

Several were actually surprised about such pronounced and repeatable effects 
with parts per billion amounts. They would expect those type of results from 
parts per million.

I am only a beekeeper and not on the level of expertise as Dr. Dave Fischer 
but one has to wonder .

To sum up in my opinion:

imidacloprid safe at parts per trillion.

imidacloprid has some effects to LD50 at parts per billion levels

Imidacloprid is a killer of bees at parts per million.

Again with looking at the above figures maybe you can see why we worry about 
the systemic effect of imidacloprid on seeds being applied year after year 
in the same field. In Bayer's defense I doubt when imidacloprid was 
registered as a systemic that their researchers would have believed that 
corn and soy bean prices would go off the charts to record highs and farmers 
would discontinue their long time practice of crop rotation and instead sow 
corn after corn and beans after beans. Farmers realize that certain fields 
grow beans better than corn and other fields produce higher yields of corn.

Beekeepers in California see little corn & beans like we do in the Midwest. 
Same for Florida. We had some flooding in Missouri this year and 3 million 
acres of corn and beans went under water along the Mississippi River. 
However only a drop in the bucket compared to the amount of acreage planted 
in those crops.

Sincerely,
Bob Harrison

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