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Date:

June 22, 2000

Subject:

angela ryan contact

 

AgBioView - http://www.agbioworld.org, http://agbioview.listbot.com

Dear Prakash

Angela Ryan has recontacted me again and has sent me two
articles she is circulating on her network and would like these
circulated on yours if you are agreeable.

Can I suggest that comments be sent directly to her at
angeal ryan

Kind regards

Tony

PS at some stage scientists from both sides are going to have to
sit down and straighten things out if possible. i don't know how or
when. Sorry to overload people again particularly Bob Goldberg. I
am not getting over consumed Bob it is just busy at present. I wish it
wasn't but I aim to get back to research in about one hour from now.

Here are two articles in upcoming ISIS News #5
Please Circulate.
Angela Ryan
ISIS


Swallowing the Tale of the Swallowtails
No "Absence of toxicity" of Bt Pollen

The paper which claims "absence of toxicity" of Bt-pollen under field
conditions is faulty in experimental design and actually demonstrates
toxicity of Bt-pollen in the laboratory.
A study in Cornell University last year (1) prompted widespread concern
that
pollen from Bt-corn may be harmful to the Monarch butterfly. Researchers
from the University of Illinois now claims that a field study on the
black
swallowtail, Papilio polyxenes, shows that Bt-pollen is not toxic to
this
species (2).
The black swallowtail feeds on host plants found in narrow strips
between
roads and crop fields in midwestern USA. A day after the start of
Bt-pollen
release, researchers set up five rows of five potted host-plant beside a
field of Bt-corn (Pioneer variety 34R07 expressing the CrylAB gene in
its
pollen), at various distances from the edge of the field. Pollen traps
consisting of a microscope slide coated with vaseline was placed with
each
plant to measure total pollen deposited. A second set of potted plants
were
placed behind the first set three days later. Ten first instar larvae
were
put on each plant, and the number of live larvae on each plant recorded
daily for 7 days.
However, no control experiments were set up. A proper control experiment
would have consisted of a replicate set of potted host plants and larvae
placed next to a non-GM corn field.
It rained during the 5th and 7th day of the first experiment, and during
the
2nd, 4th and 5th day of the second experiment. Would that not have
washed
away the pollen from the surface of the leaves. If so, what relevance
would
the pollen counts - on greasy pollen traps - have on actual pollen
ingested
by the larvae?
Pollen counts decreased sharply with distance from the field as
expected;
but there was no correlation between pollen counts and mortality. Even
though the larvae were counted everyday for seven days, the detailed
counts
were not given. Instead, the aggregate percentage mortality was
presented.
Not only were the mortalities high, they were also highly variable. The
means ranged from 45 to 82%, and in many cases, the standard deviation
in
each direction was almost as large as the mean. It was obviously
impossible
to draw any conclusion from such an experiment. But they stated, "No
significant relationships between larval survivorship or mass were
detected
either as a function of distance from the edge of the field or as a
function
of pollen deposition." That was true, but the main reason may be that it
was
a bad experiment. They suggested that the high mortalities might be due
to
predation. If so, would mortality not be correlated with "larval mass"?
Yet
no such correlation was reported.
Back in the laboratory, they deposited different amounts of Bt and non
Bt
pollen on leaf-discs and fed each in a single dose to a first instar
larva
which was observed over the next three days. They found no effect with
the
Bt-pollen collected from the field, even at the highest dosage. But
exactly
how much Bt toxin did each larva consume? From the figures presented, it
can
be calculated that at the highest dose used - 10 000 pollen grains - the
larva would have consumed only 1 picogram of Bt protein, ie, 1/1 000
000
000 000 or one trillionth of a gram, over the three days.
With another Bt-corn pollen - Novartis Max 454 - which expresses 40 times
as
much Bt protein, ie, 40 picograms, a highly significant increase in
mortality was found on the third day: 80% compared with about 10% for
the
rest.
As the laboratory experiments involved feeding a single dose over three
days, it gave no information as to the effects on mortality of
cumulative
doses over the entire life-cycle of the butterfly, such as it may
experience
in the field.
The claim of "absence of toxicity" in the title of this paper is thus
misleading to say the
least. It will be an abuse of science if this report were to be accepted
as
evidence that Bt-pollen is safe for black swallowtails.
References and Notes
1. Losey, J.E., Rayor, L.S. and Carter, M.E. (1999). Transgenic pollen
harms monarch larvae. Nature 399, 214.
2. Wraight, C.L., Zangeri, A.R., Carroll, M.H. and Berenbaum, M.R.
(2000). Absence of toxicity of Bacillus thuringiensis pollen to black
swallowtails under field conditions. PNAS early Ed.
Mae-Wan Ho

To Bt or Not to Bt
The Sound Science that brought down Bt Crops

Since the publication of Losey's study in the journal Nature showing
that
Bt-corn pollen harms monarch butterflies, things have gone into a
downward
spiral for Bt-crops. Bt-corn is now banned in Austria, France and
Germany,
and Monsanto's Bt-potato division has been closed down by its new parent
company, Pharmacia.
'Bt' is short for Bacillus thuringiensis, the soil bacterium providing
the
genes for making toxins that kill insects; different forms of which are
incorporated into GM crops. The adverse environmental impacts of Bt
crops
are now well documented in the scientific literature, ranging from harm
to
non target organisms to the evolution of resistance in insect pests,
making
it necessary to plant a high proportion of non-Bt crop for 'resistance
management'. Aberrant gene expression in the field results in low-dose
varieties which are ineffective
in pest control and foster resistance. Cross pollination with non GM
varieties creates Bt-weeds, and the Bt-plants themselves cause major
problems as volunteers. Active Bt toxin leaks from plant roots into
the
soil where it is not biodegradable and accumulates over time. This
will
have major impacts on soil health, with knock-on effects on all other
trophic levels of the ecosystem. The recent report that a GM gene has
transferred from GM pollen to microbes in the gut of bee larvae
underlines
the fact that Bt toxin genes, like all other GM genes, will spread out
of
control. The case for withdrawing all Bt-crops is now compelling.
The way the case has been built is exemplary of the power of good
independent science, which is indispensable for sound policy decisions.
No less than eighteen Bt crops were approved for field testing by the US
Dept. of Agriculture between 1987 and 1997 (1). Bt cotton was the first
to
be approved for commercial use (USA 1995), followed by corn, potato and
tomato.
The first specific concerns on the safety of Bt crops were raised from
within the scientific community in 1997 when Angelicka Hilbeck and
colleagues (2) showed that lacewings fed on pests that have eaten
Bt-maize
took longer to develop and were two to three times more likely to die.
Organic farmers also started to voice their fears - they have been using
the
spores of Bacillus thuringiensis as an occasional insecticide spray.
Their
fear was founded in the rapid development of resistance to Bt toxin in
pest
populations continuously exposed throughout the GM plant's growing
season,
with the potential loss of their only organic insecticide. They were
also
worried about GM contamination via cross-pollination - now admitted as
unavoidable by our regulators.
Then came Losey's famous Monarch butterfly study (3), which was
confirmed
by
another from the University of Iowa (4), showing that milkweed in and
at
varying distances from Bt crops in the field does cause an increase in
mortality to Monarch butterflies. Milkweed samples were taken from
within
and at the edge of the Bt corn field and were used to assess mortality
of
first instar monarch, D. plexippus exposed to Bt and non-Bt corn pollen.
Within 48 hours, there was 19% mortality in the Bt corn pollen
treatment,
compared to 0% on non Bt-corn pollen exposed plants and 3% in the no
pollen
controls. This second study counters all the spurious arguments that
the
Losey's study was a 'worse case scenario' that bears no relevance to
field
conditions. Besides which, when Losey conducted his experiments he did
not
spatula Bt pollen on to the leaves of milkweed, as was reported by
industry,
he dusted the leaves in accordance with levels observed in the field.
In a desperate recent attempt to counter this evidence, the pro-biotech
lobby has just released a story claiming that pollen from Bt corn does
not
harm the black swallowtail. This story has been thoroughly deconstructed
(see "Tale of the Swallowtail", this issue).
The biotech industry is fully prepared to misreport research results in
order to confuse and mislead the public. On Nov 2nd 1999, a scientific
meeting took place in Rosemount, Illinois, to discuss Bt corn and
monarchs.
That same morning, all the major news desks round the US received a fax
carrying a News article about the meeting - which had only just begun at
that point - headlining 'Researchers conclude Bt corn poses little risk
to
Monarchs'.
Luckily, Carol Yoon of the NY Times was at the meeting and received word
from her editor in New York. She asked the participants if they agreed
with
what was obviously a press release from industry. The answer from the
floor
was a resounding "No" - her report was the only accurate account of the
meeting, but unfortunately, the majority of US citizens got the
industries'
take on it (5).
After months of heated debate on the effects of Bt on non-target
insects,
the US Environmental Protection Agency (EPA) convened a Scientific
Advisory
Panel (SAP) meeting in Dec 1999 and asked the panel to review EPA's
non-target organism testing requirement, applicable to Bt crops. The
panel
found EPA requirements inadequate and urged the agency to substantially
expand the scope and quality of the studies that it relies upon (6).
Plans for managing the development of Bt-resistance in insect pests have
been actively debated in the scientific literature, and earlier this
year,
the EPA revised their original mandate and ruled for larger refuges of
non
GM crop planted with the GM crop. This was hailed as a step in the right
direction and now refuges have to be at least 20%. But major
controversies
remain as to whether or not the refuges should be sprayed by
conventional
insecticides (7). A study in the University of Arizona (8) showed that
boll worm larva fed on GM and non GM develop at different rates and it
is
highly unlikely that they will interbreed, dashing any hopes of diluting
out
or slowing down the evolution of resistance. These moths mate within
three
days of hatching and the males only live for a week. Also, dilution only
works if the Bt-resistance is recessive, ie, requiring two copies of the
resistance gene to be expressed, and the EPA's resistance management
program
relies on the trait being recessive. Unfortunately, studies on the
inheritance of Bt resistance showed that it is a dominant trait (9) as
insects with only one copy of the resistance gene survive
exposure to Bt. Low levels of Bt expression in Bt crops has also been
documented and also serves to foster resistance.
Other scientists (10) have designed elaborate choice experiments that
seek
to understand insect behavior in terms of 'pollen avoidance', which will
affect the evolution of Bt-resistance. However, by their own admission,
these data can not be used to arrive at any conclusions about the effects
of
Bt toxin-containing pollen. This work does however highlight the need to
consider complex behavioural as well as toxicological aspects.
In June1999, Monsanto applied for the first Experimental Use Permit on
CRY3Bb transgenic corn, another Bt corn line aimed at corn rootworm.
The
application has been thoroughly assessed by an alliance of four
independent
non profit organizations (11), who report the most astonishing findings.
The
technical study submitted by Monsanto in July 1999 contained no
molecular
data, nor data on the breeding regime, for three different Bt lines.
Data
on the levels of protein expression in different tissues was included.
But
300 corn plants were produced for only two of the transformation
experiments, and some of the critical measurements of expression levels
were
done on only two plants. Despite this, the data clearly indicate that
different transformations led to significantly different levels and
patterns
of protein expression. Such differences are of crucial important in
assessing efficacy, resistance management and non-target impacts, as well
as
changes in the microflora of the digestive systems of livestock and
humans
using the crop for food.
Monsanto then submitted its application in full in August 1999, moving
from
greenhouse-scale research to unrestricted field use in one year. In the
covering letter they wrote; "Please note that approval of this
registration
by May 2000 would reduce the need for additional submissions and reviews
for
year 2000 field trials". This statement makes it blatantly obvious
that
Monsanto has no intention of investigating their findings any further
with
respect to health and environmental impacts. To date their application
in
full is still pending in the US but has been granted commercial
approved
in Puerto Rico and Hawaii for this growing season.
In Dec 1999, Gunther Stotsky and colleagues (12) reported that Bt toxin
is
released into the rhizosphere - around the plant roots in the soil - in
exudates from the roots of Bt corn, where the toxin is protected from
biodegradation and accumulates. This raised, for the first time, the
question of what is happening underground? A total of 15 million acres
of
Bt corn were planted in the US in 1998, 20% of the total acreage. The
leaked
toxin enters the soil in an activated form - Bt transgenes are truncated
to
produce active toxin, unlike the precursor-form produced in the
bacterium,
which has to be cleaved in the gut of susceptible insect pests.
Moreover,
the toxin is expressed continuously, and hence exuded for extended
periods
of time.
In organic farming the toxin is sprayed sporadically in an inactive
precursor form, only becoming active in the gut of the target insects
once
ingested. Furthermore, it is sprayed onto the surface of plants where it
is
readily biodegraded. Stotsky suggests that the widespread planting of
Bt
crops is equivalent to added large doses of active toxin to the soil,
not
only from the plant root but also from the plant residues after
ploughing
in, as well as from pollen. There is at present no clear indication as
to
how soil communities might be affected by Bt toxin from root exudates.
It
may promote selection of toxin resistant target insects. But receptors
for
Bt toxins are present in both target and non-target insects, therefore
both
will be affected. Bt toxins are active against insects in the Order of
Coleoptera (bettles, weevils and styloplids) which contains some 28,600
species, far more than any other Order (13). The widespread use of Bt
genes in crops and the build up of active toxin in the soil will have
long
term ecologically risks to non-target species and organisms in higher
trophic levels, such as birds.
Simultaneously, it was reported that Novartis had filed a patent for
another
insecticide to be used in conjunction with Bt crops (14). It turns out
that
the pest-control spectrum of Bt toxins is limited, and other pesticides
have
to be used, that have been shown to be very damaging to health. This
completely discredits the industry's claim that Bt is essential for
reducing
harmful pesticide use.
This April brought further reports on pockets of Bt-resistance among
pests
in GM fields, and of GM cotton plants turning up as weeds in other crops
(15). The cotton boll weevil may make a come back if such volunteers
are
ignored. An entomologist at Clemson Univ. said, "I could look across
soybean
fields and see hundreds of these Bt cotton plants". A return of this
pest
to parts of the American Cotton Belt would be a disaster, considering it
cost $1.3 million to eradicate them by 1995.
The ecological interaction between organisms is complex and
scientifically
challenging. The behaviour of insects with regard to choice' of food can
have important impacts. This aspect has been overlooked completely in
environmental risk assessments of GM crops. Researchers at Rothamstead
in
the UK (16) have pointed out that killing non-target species is a risk
not
unique to GM technology, as conventional regimes actually kill insects in
an
indiscriminate manner that is equally unsustainable. They highlight the
need to find alternatives to conventional practices and suggest that
management and good husbandry of bio-control agents should act in an
integrated manner to eliminate caterpillars.
The health assessment of Bt crops relies totally on past experiences with
Bt
sprays in organic farming. It is wrong to assume that Bt toxin in GM
crops
is the equivalent to what has been used for over thirty years on organic
produce with no effects. As with all GM crops, comprehensive feeding
trials
have yet to be conducted and therefore there is no data supporting the
safety of eating Bt crops. Furthermore, there is a general lack of
scientific transparency with all GMOs and Bt-crops are no exception.
Crucial
data are withheld from the public domain under various confidentiality
statements made by the biotech companies in their applications for
license.
Leading US Agronomist, Charles Benbrook has just completed a
comprehensive
review on EPA's management of Bt-corn (17). It provides important
insights
into the structural and legal shortcomings in the approval process, the
major among which was the failure to adhere to the precautionary
principle.
The summary of findings reported by independent scientists investigating
or
evaluating environmental risks are sufficiently compelling to warrant
the
immediate withdrawal of all Bt crops from use.
Notes and references
1. ISB Environmental Releases Database for USDA APHIS website :
www.aphis.usda.gov/bbep/bp/index.html
2. Hilbeck, A., Baumgartner, M., Fried, P.M. abd Bigler, F. (1997).
Effects
of transgenic Bacillus thuringiensis-corn-fed prey on mortality and
development time of immature Chrysoperla carnew (Neuroptera:
Chrysopidae)
Enivronmental Entomology 27, 480-487
3. Losey. J., Raynor. L., & Carter. M. E., (1999) Nature 399,214
4. See: http://www.ent.iastate.edu/entsoc/ncb99/prog/abs/D81.html
[Non-target effects of Bt corn pollen on the Monarch butterfly
(Lepidoptera:Danaidae) *L. Hansen, Iowa State University, Ames , IA
50011
and J. Obrycki, Iowa State University, Ames, IA 50011. Contact e-mail:
lrahnsen@iastate.edu ]
5. First Hand Account ^ Industry manipulation of Bt research, by Beck
Goldburg, Environmental Defense Fund. Forwarded to Biotech Activists
11/05/99
6. The final report of the SAP panel is accessible at
<http://www.epa.gov/scipoly/sap/1999/december/report.pdf>
7. Shelton, A.M., Tang, J., Roush, R.T., and E. Earle. (2000) "Field
tests on managing resistance to Bt- engineered plants, Nature
Biotechnology,
Vol 18;399-342
8. Liu, Y-B., Tabashnik, B.E., Dennehy, T.J.,Patin, A.J., & Bartlett,
A.C.
(1999) Nature 400:519
9. Huang, F., et al. (1999) Science 284, 965-967
10. Tanja H. Schuler, Roel P.J. Potting, Ian Denholm, Guy M. Poppy
(1999)
Parasitoid behaviour and Bt plants. Nature Vol 400 pp 825
11. Comments Submitted to Docket No OPP-30487a: Registration
application
for
CRY3BB transgenic corn modified to control the corn rootworm March 20
2000.
On behalf of Environmental Defense, the Institute of Agriculture and
Trade
Policy, the Science and Environmental Health Network, the Center for
Food
Safety, and the Consumer Policy Institute/Consumer Union.
12. Deepak Saxena, Saul Flores, G. Stotzky (1999) Insecticidal toxin
in
root exudates from Bt corn. Nature Vol 402 pp 480
13. Arnett, R.H., and R.L. Jacques. Guide to Insects, Simon and
Schuster.
1981.
14. Genetically modified plants may still need pesticides, By Andy
Coghlan
and Barry Fox, New Scientist, 18.12.99
15. Pockets of resistance : A pest might make a comeback thanks to
engineered weeds. New Scientist, By Andy Coghlan April 15 2000.
16. Poppy, G. (2000) GM crops:environmental risks and non-target
effects,
Trends in Plant
Scienc 5 , 4-6.
17.Charles Benbrook and Steve Suppan June 2000. Applying the
Precautionary
Principle in Assessing Transgenic Corn Technologies in the US. See
<http://www.biotech-info.net/case_studies.html>
Angela Ryan



----------
>From: "Tony Trewavas"
>To: "Angela Ryan"
>Subject: debate
>Date: Fri, Jun 23, 2000, 9:43 am

Anthony Trewavas FRS
Institute of Cell and Molecular Biology
Mayfield Road
University of Edinburgh
Edinburgh EH9 3JH
Scotland
Phone 44 (0)1316505328
Fax 44 (0)1316505392
email Trewavas@ed.ac.uk
web site http://www.ed.ac.uk/~gidi/main.html
To view the web site simply click on the address