Paul Cherubini wrote:

> Robert Mann wrote:
>
> > The Cornell experiments by Losey et al. showed monarch
> > butterfly larvae severely poisoned by Bt corn pollen.
>
> The Cornell study was not representative of actual field conditions.
> Subsequent field studies to date has found Bt corn pollen does
> not harm non-target butterfly larvae in real world field situations.
>
> This is what the biotech industry expected since the concentration
> of the crystalline endotoxin in Bt corn pollen is extremely low and
> incapable of controlling even the target lepidopterans (e.g.the european corn
> borer moth) For example, in Monsanto's Bt corn, (called MON 810)
> 1994 field data demonstrated expression levels of
>
> 0.18-0.39 ug/g in the kernal
> 7.93 -10.34 ug/g in the leaf
> 3.65-4.65 ug/g in the whole plant
> 0.09 ug/g in the pollen
>
> These figures show the amount of toxin in the pollen is around 36-103
> times less than what is present in the whole Bt corn plant and leaf tissues
> (what the lep larvae must actually eat to be killed)

The assumption here is that all Bt corn is the same.

>
> > Genetic modification (GM), also called genetic engineering (GE), is
> > a topic to concern beekeepers.  If bees feed their larvae pollen containing
> > -  to no good purpose  -  a modified version of a Bt toxin, then plant-GM
> > might harm bees.  There are many other possible scenarios of harm to bees
> > from GE plants.
>
> It must be remembered Bt is nothing new - foliar sprays of Bt have
> been used on row crops for decades. They have proven to be non-toxic
> to non-lepidopteran insects such as honey bees (both larvae and adults).
>

The difference here is that the spray is not on/in the plant 24 hrs a day seven
days a week. Many toxins have acute or chronic exposure effects. Also, the Toxin
produced from live bacteria is generated inside the gut -- if conditions don't
favour growth of the bacteria then tha toxin is not produced.

>
> The US Environmental Protection Agency has published a Fact Sheet
> on Monsanto's Bt corn variety (event) which is called MON 810.

You can be 100% sure that the so-called fact sheet is based 100% on Monsanto's
own [biased] research.

> Below
> is what the fact sheet reports in regard to the toxicity of Bt protein
> to honey bee larvae and adults (and other non-target insects):
>
> "4. Impacts on Non-Target Organisms
>
> a. Impacts on Non-Target Insect - Honey Bee (Larvae) B.t.k. HD-1
> protein at 20 ppm is practically non-toxic to larval honey bees.

Note the use of the term, "Practically." Either it is or it isn't.

> An
> LC50 was not possible to calculate since this was a single dose test.
>

A single dose test gives a great deal of confidence I'm sure.

> Therefore, the NOEL is greater than 20 ppm."
>

If this said 'less than' it would be much more reassuring.

>
> b. Impacts on Non-Target Insect - Honey Bee (Adult)
>
> There were no statistically significant differences among the various
> treatment and control groups due to the sizable mortality that occurred
> in all treatments.

Why was there a 'sizable mortality' in all treatments? The fact that the test
appears to have been undertaken once is hardly reassuring -- especially when the
results were meaningless due to other factors.

> B.t.k. HD-1 protein at 20 ppm resulted in a mean
> mortality of 16.2%. Because mortality was observed at the single dose
> tested, a NOEL could not be determined from this study, but it was
> less than 20 ppm.

Previously the results for larvae were 'greater than' 20 ppm.

> 20 ppm was determined to be significantly higher
> than exposure conditions in the environment.
>

How was it determined to be so?

>
> c. Impacts on Non-Target Insect - Parasitic Hymenopteran
>
> B.t.k. HD-1 protein at 20 ppm is practically non-toxic to
> Brachymeria intermedia. Since this is a single dose study,
>  an LC50 cannot be calculated. The NOEL is greater than 20ppm.
>

Again, NO[A]EL is greater than 20ppm.

>
> d. Impacts on Non-target Insect - Green Lacewing Larvae
>
> B.t.k. HD-1 protein at 16.7 ppm is practically non-toxic
>  to green lacewing larvae after 7 days.
> The NOEL is greater than 16.7 ppm.
>

This is the third time we've seen the words 'practically non-toxic.' This means
that it is! It also shows how positive tests have not been confirmed. Why not?

>
> e. Impacts on Nontarget Insect - Lady Beetles
>
> B.t.k. HD-1 protein at 20 ppm is practically non-toxic
> to lady beetles such as Hippodamia
> convergens. The NOEL is greater than 20 ppm.
>

The fourth 'practically non-toxic.' This is hardly unequivical stuff -- It's
hardly reassuring. If this comes from a fact sheet then the only fact established
is that Bt corn is toxic (practically non-toxic is a bit like pleading that one
is only a little bit pregnant) and that single tests undertaken failed to detect
significant differences in one case due to high mortality rates in all test
groups.

This is hardly reassuring science.

Regards
Ron Law