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2-Plants: Canadian responses on Monarch butterfly study

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TITLE:  Canadian responses on Monarch butterfly study
SOURCE: National Post, Canada, edited by AGNET
DATE:   May 20, 1999

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This story begins by saying that genetically engineered corn,
which the Canadian government approved for widespread use saying
it is has no serious environmental impacts, is so loaded with
"natural pesticides" that its pollen can kill the larvae of the
celebrated monarch butterfly.

Michelle Swenarchuk of the Canadian Environmental Law
Association, which is pushing for much tougher evaluation and
regulation of genetically engineered crops, was quoted as saying,
"There should be long-term environment impact studies done before
these crops are allowed on the market. You'd think that would be
pretty basic, but not for our government, which has decreed these
things are safe without ever doing such studies."

Simon Nadeau, Environment Canada's advisor on species at risk,
was cited as saying he is concerned about the U.S. findings,
which he describes as "scary."

Morven McLean, chief of the Canadian Food Inspection Agency land
biotechnology office, was cited as saying it is "not a surprise"
that the Bt corn can be deadly to monarch larvae since it has
always been known that moth and butterfly larvae are susceptible
to the toxin in Bt corn. But she says it was not known that the
toxin level in the pollen was high enough to kill monarch larvae.
McLean added that the Cornell study is "very preliminary" and
much more research needs to be done to answer the many questions
raised by the experiments. McLean, according to this story, said
her office has no plans to finance the studies that could answer
those questions, as well as determine if rules governing the use
of Bt corn in Canada need to be revised. She expects that work
will be done by others, but could not say whom. She said her
office will be in touch with Environment Canada and other
interested scientists to discuss the issues raised by the study.

The story says that Canadian regulators, who approved the first
of several varieties of Bt corn in 1996, have long dismissed the
idea that Bt corn could seriously impact monarchs and other non
target moths and butterflies. McLean was cited as saying in the
past the impact is probably minimal, since monarchs eat milkweed,
not corn. She and her colleagues also suggest the new crops have
a positive environmental impact because they reduce the need to
spray pesticides. Critics counter that Bt crops could be worse
since the toxins are present not for a few days after spraying,
but throughout the entire growing seaso n, and shed pollen which
can waft out of fields into woodlots, ditches, and empty fields.
Monarchs, which are officially listed as a "vulnerable" species
by Environment Canada, make a legendary migration to wintering
grounds in Mexico in the fall and return in the spring to breed
in Canada and the United States. The estimated 100 million
butterflies are increasingly threatened by forest destruction on
their wintering grounds and it appears, based on the Cornell
study, by biotechnology on their summering grounds.

Nadeau, the Environment Canada advisor, is surprised by the
study's "scary" findings since he had assumed the pollen from the
corn did not contain the Bt toxin. He suggests that CFIA
assessors might want to take a more thorough look at
environmental impacts before approving GM crops, adding, there
appear to be "gaps" in the existing assessment procedures. Nadeau
stressed that the destruction of forests on Mexican mountaintops
is a much more serious threat to the monarchs than Bt corn at
this stage. But he says the study certainly suggests Bt corn "is
an additional threat to a vulnerable species." How big a threat,
he says, can only be determined by assessing the impacts and
movement of Bt corn pollen in the field and gauging its toxicity.

David Gibo, a monarch specialist at the University of Toronto,
was cited as saying he was not about to jump on the anti-Bt-corn
bandwagon because of the new study, and that he suspects both the
Cornell scientists and Nature are being "political" by publishing
the study, which used questionable methods. Particularly
troubling, he says, is the way the U.S. researchers dusted
milkweed leaves with pollen to "visually match densities" on
milkweed leaves collected from corn fields. Gibo was quoted as
saying, "It doesn't sound very scientific at all," adding that he
feels the scientists should have measured exactly how much pollen
was on the milkweed leaves.

Several varieties of Bt corn are approved for use in Canada, but
McLean could not say how many farmers are using the varieties
since her agency does not track how widely the crops are used.
(The story says that there are also several varieties of
herbicide tolerant GM corn approved for use.) While there are no
plans for studies of the impact of the crops on monarchs at this
stage, Dr. McLean and her colleagues have approved several field
trials, to be conducted by private and public-sector scientists
this summer, involving several new varieties of corn and potatoes
that have been given Bt genes. The Bt gene in potatoes targets
only beetles, McLean said.


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