AgBioView - http://www.agbioworld.org, http://agbioview.listbot.com
Date: Jun 06 2000 17:57:30 EDT
Subject: monarch butterflies
Not to beat a dead horse but below is the letter I wrote to NPR regarding
their recent report on Monarch Butterflies. John Cross and Ray Shillito
already covered most of the points in my letter to NPR but I thought I
would share it with the group anyway.
The report on Friday June 2nd on Monarch Butterflies featuring Lincoln
Brower was a puff piece that not only did not ask any tough questions but
treated an old story (Monarchs in the lab being killed by Bt pollen) as
new, while barely mentioning the research and important information that
has become available
since then indicating no or extremely small risk to monarchs in the real
world. For example recent studies indicate that dispersal distances for
corn pollen are very low and densities of Bt pollen on milkweed decreases
to sublethal levels at very small distances. This would have been
pertinent to add to the piece. And how about asking a couple "tough
journalistic questions" to Brower at least? For example "Do you favor use
of Bt spray by organic farmers despite its potential harm on monarchs?"
After all they both (Bt pollen and Bt spray) are ephemeral in nature.
Does he prefer insectide use (that certainly could have a
negative impact on Monarchs) for controlling pest in agriculture over GM
insect resistance? If so, then Why? At the same time the most important
threat to monarchs, deforestation of their breeding grounds, was barely
discussed. Most listeners probably got the overall impression that
monarchs are in peril and its
likely due to Bt Corn. What a load of bull.
Date: Jun 07 2000 07:49:00 EDT
Subject: Fwd: And in this bee our two genes mingled be
From: Conrad Lichtenstein
A misguided media swarm
GM food: special report
Tuesday June 6, 2000
Once again a preliminary, uncompleted and unpublished piece of
scientific research makes headlines as a new GM scare story. First it
was toxic GM potatoes that triggered the GM media frenzy in 1998.
When finally published in the Lancet the following year, original
claims were not supported.
Then it was that Monarch butterflies are killed by GM maize. The
plants express Bt - a natural insecticide of bacterial origin which
some organic farmers spray on to their crops and it is hardly
surprising that butterflies are killed when fed such GM maize pollen
in the laboratory. But in the field not having to spray chemical
insecticides has actually led to an increase in butterflies. Now the
latest scare story is that young honey bees can acquire transgenes
encoding herbicide resistance from GM pollen and transmit these to
microbes living in their gut. This comes from unpublished research of
Professor Hans-Hinrich Kaatz from the University of Jena, Germany.
What are the requirements for such gene transfer? What are the
implications if this story turns out to be true?
Bacteria can indeed take up DNA from their environment. But if
incorporated, for such DNA to remain there over many generations,
another condition, first taught to us by Charles Darwin in 1859, must
also be met. To survive natural selection and spread through a
population, a newly endowed genetic characteristic must also give an
organism that carries it an advantage that allows it to produce more
descendants than those that do not.
The importance of selection is illustrated in the excessive use of
antibiotics both to combat infectious disease in humans and as a food
additive to boost growth in livestock. Since the 60s, this has
resulted in the new appearance of bacterial pathogens with multiple
antibiotic resistance. How did this happen? Soil bacteria produce
antibiotics for waging chemical warfare upon their competitors but
also have antibiotic resistance genes, to equip them with antidotes
against their own toxins.
These resistance genes can transfer naturally between bacteria and
must have done so since time began. But they have spread among
bacterial pathogens only now following artificial selection for this
new advantage. An advantage which is new only because of the new use
of these antibiotics to combat infectious disease. So if honey bees
can transfer GM genes to microbes, then they can surely also transfer
any other plant DNA too? And indeed must have been doing so for the
last 125m years or so since bees and flowering plants first
But for such genes to have spread into bacterial populations they,
similarly, must be expressed to produce a new protein which gives a
new selective advantage to the microbe.
The GM debate is too important to be a propaganda war of soundbites
and emotive invective. Since "ordinary citizens", as members of a
jury, can evaluate evidence, including that from "expert" witnesses,
to seek justice in the law courts, they should surely be given the
same opportunity on GM and other new technologies.
Scientists and journalists must seek the truth whatever it is and use
direct experimental evidence to support their views. But, at a recent
GM debate, I was alarmed to hear an anti-GM university biologist
state that GM genes are more resistant to the natural processes by
which enzymes break down other DNA and that GM genes, as they are
designed to "invade" genomes, are also more unstable and can more
easily move around, dangerously spreading.
During question time, I asked for direct experimental evidence to
support this but was given the techno-babble which puts fear into the
hearts of the scientifically uneducated. My questions remained
I know of no experiments to support such statements, nor from my own
two dozen years of research experience on GM plants, genetic
recombination and gene jumping between species, can I conceive of any
credible biological mechanism that would permit it.
People given a public voice must not use their scientific credentials
to make public statements that they do not support with hard
experimental evidence. That is not science. And it is irresponsible.
The author is professor of molecular biology at Queen Mary and
Westfield College, University of London.
Conrad Paul Lichtenstein
Professor of Molecular Biology
School of Biological Sciences
Queen Mary & Westfield College
University of London
London E1 4NS, England
BUTTERFLY OK AFTER TEST OF BIOTECH CORN
Corn that is genetically engineered to kill an insect pest is not a
threat to at least one common type of butterfly, according to the
first of a series of field studies being conducted to determine
whether the crop is a danger to the environment.
University of Illinois scientists placed black swallowtail butterflies
near a farmer's field and found no evidence that they were harmed by
the biotech corn, according to research appearing Tuesday in the
Proceedings of the National Academy of Sciences.
The biotech corn, known as Bt corn for a bacterium gene that makes
it toxic to the European corn borer, became controversial last year
after a laboratory study at Cornell University suggested it could be
killing monarch butterflies. The finding produced a public outcry in
Europe and calls from environmental groups to curb the spread of
gene-altered crops, but biotech supporters said the lab research
didn't replicate actual field conditions.
"This is not a pest management tool that should be rejected outright
based on a single lab study," said May Berenbaum, head of the
University of Illinois entomology department and the lead scientist on
the swallowtail research.
"By the same token this is not a blanket endorsement of all
genetically manipulated plants. If anything, it argues for more
ecologically realistic testing."
The swallowtail is considered to be less sensitive to the corn toxin
than the monarch, but the swallowtail is much more likely to be
exposed to the pollen. Unlike the migratory monarch, the swallowtail
goes through several generations in the same place each summer, so it
is more likely to be near a corn field during the days when the plants
are shedding their pollen, the researchers said.
Farmers were expected to plant about 14 million acres of Bt corn this
year, 18 percent of the total corn acreage.
New York Times
June 6, 2000
Type of Biotech Corn Found to Be Safe to a Butterfly Species
By CAROL KAESUK YOON
A strain of genetically modified corn that produces its own insecticide,
known as Bt, does not appear to harm black swallowtail butterflies in the
wild, according to a report published today in The Proceedings of the
National Academy of Sciences.
In May 1999, scientists at Cornell reported in the journal Nature that
monarch butterfly caterpillars died after eating Bt corn pollen in
laboratory experiments, raising concern that these crops could be causing
unintended harm to monarchs and other insects.
The new research on the swallowtail butterfly is the first published field
study conducted since then to look for potential effects from genetically
The research team from the University of Illinois had studied the
widespread swallowtail butterfly for years. In this study, it found that
both in the wild and in the laboratory, swallowtail butterfly caterpillars
did not appear to be harmed by eating leaves dusted with pollen from a
popular strain of Bt corn known as Mon 810. The Bt toxin is aimed at
killing European corn borers, which can cause major damage to corn crops.
''The implication is that the impacts of Bt corn might not be as great as
were initially assumed,'' said Dr. May Berenbaum, ecologist at the
University of Illinois and an author of the study, which was paid for by
the University of Illinois Environmental Council.
But Dr. Berenbaum added, ''I'm not saying Bt corn is just fine.''
In fact, both those who were and were not involved with the new study
cautioned against overgeneralizing from these latest findings.
Dr. Berenbaum noted that her team also found that another strain of Bt
corn, known as 176, which has particularly high levels of toxin in its
pollen, was toxic to swallowtail butterflies in the laboratory.
The finding suggested that while Mon 810 may be safe, other strains of Bt
corn could pose a threat to swallowtails. Researchers will be studying the
effects of strain 176 on swallowtails and monarchs in the field this
Researchers also agreed that the new study and the Cornell study could not
be directly compared since they involved different butterfly species and
different strains of Bt corn. The Cornell study used another popular
strain known as Bt 11.
''This study is important because it's one more species,'' said Dr. John
Losey, the lead author on the Cornell study.
But Dr. Losey echoed researchers on the new study, adding: ''It would be
just as wrong to look at black swallowtails and say Bt corn is safe as it
was wrong when people looked at monarchs and our lab study and said
there's definitely a problem. I'm not ready yet to say either.''
He said some 100 species of butterflies and moths could potentially be
affected by Bt corn pollen.
For those looking to mitigate the potential impact of genetically modified
corn, however, the new study suggests that there may be strains of Bt corn
that have little or no impact on nonpest species, said Dr. Arthur Zangerl,
another author of the new study.
Since the study on monarchs was published a year ago, critics of
regulatory agencies have cited its findings as a sign that environmental
risks are not being adequately monitored. The monarch itself has been
brandished as a symbol by critics of genetic engineering.
But biotechnology advocates have defended the new crop, saying that it has
decreased the use of pesticides and that the risks to monarchs, if they
exist, are likely to be minimal.
St. Louis Post-Dispatch
June 6, 2000
Genetically modified corn doesn't harm butterfly species, U of I study
By Tina Hesman
The most widely planted variety of genetically engineered corn seems to
have no adverse effects on black swallowtail butterflies, University of
Illinois scientists report.
Earlier laboratory studies that were heavily publicized last year
indicated that monarch butterflies are killed by a pesticide in the pollen
of genetically modified corn. But many scientists have said they believe
that the risk to butterflies in the wild is actually small.
To find out, the Illinois researchers conducted their study of 500
swallowtail butterflies in corn fields around Urbana. "We came into this
study not knowing what we were going to find," said entomologist Arthur R.
The study was funded by the University of Illinois Environmental Council.
The results of the study, to be published today on the Web site of the
Proceedings of the National Academy of Sciences, indicate that black
swallowtail butterfly caterpillars aren't harmed by pollen from corn
altered to contain a toxin from the naturally occurring bacteria Bacillus
"Given a real-world setting we weren't able to document any impact" of the
genetically engineered corn pollen on the insects, said Zangerl.
Zangerl said that although the researchers were "quite relieved" to find
that the swallowtail butterflies weren't affected by the modified corn
pollen, it would be premature to say all butterflies are safe from the
effect of the Bt toxin.
In a May 1999 report in the journal Nature, Cornell University researchers
found that monarch butterfly caterpillars in their lab died after eating
pollen from Bt corn. The Illinois research is the first published field
study on butterflies and Bt corn.
"We can certainly say at this point that things look pretty safe for the
black swallowtail," said Iowa State University ecologist John Pleasants,
who has been doing research related to Bt corn. However, he said, "what's
safe for a black swallowtail may not be safe for a monarch."
In their own laboratory studies, Zangerl and his colleagues found that
pollen from a variety of Pioneer corn containing a Monsanto-engineered
toxin didn't kill the black swallowtail caterpillars even when the pollen
was dense enough to turn leaves yellow. But a different strain of corn
made by Novartis had enough pesticide to kill the caterpillars even when
the researchers were unable to see pollen on the leaves.
The researchers plan to study the effects of the Novartis corn on both
monarch and black swallowtail butterflies this summer.