<font color=DarkOrchid>Yet another biotech corn / monarch butterfly article.
September 26, 2000
Biotech Corn Isn't Serious Threat to Monarchs,
Draft U.S. Report Finds
By CAROL KAESUK YOON
In a finding that is being hailed by
the biotechnology industry and
denounced by environmentalists,
the Environmental Protection
Agency has issued a preliminary
report concluding that genetically
modified corn is unlikely to pose a
serious threat to monarch butterflies.
The report, which was made public
last week and focuses on crops
genetically modified to produce an
insecticide known as Bt, also
minimized the potential for other
environmental problems, including
the persistence of the insecticide in
the soil and the evolution of pests
that can withstand it.
"Although there may be individual
butterflies that could be adversely
affected, the overall population of
monarch butterflies is not at any
risk" from Bt corn, Brian Steinwand,
a spokesman for the environmental
agency, said. But he said the report's conclusions were tentative and that new
data were continuing to come in. Bt stands for Bacillus thuringiensis, the
scientific name of the bacterium from which the toxin and the gene
producing the toxin originate.
The report comes after more than a year of controversy following the
publication of a Cornell University study showing that Bt-containing pollen
from the genetically modified corn could kill monarch butterfly caterpillars in
the laboratory. That finding turned the monarch into a symbol of fragile
nature threatened by biotechnology. Opponents criticized the environmental
agency for approving the corn, which was planted on 20 million acres last
year.
The report is a major step in a continuing re-evaluation of the safety of Bt
crops that will culminate in a decision next fall to discontinue or reapprove
their widespread commercial use. Meanwhile, the report noted, companies
are phasing out Bt corn varieties that produce a particularly toxic pollen —
those that carry the genetically engineered DNA known as Event 176. The
change could help reduce risks to monarchs and other nonpest insects.
Dr. Val Giddings, vice president for food and agriculture at Biotechnology
Industry Organization, which represents companies that sell seed for
genetically modified crops and other biotech products, praised the report. He
called the review rigorous, and said it confirmed that biotech crops "pose no
adverse health or environmental problems."
But Dr. Jane Rissler, a senior scientist at the Union of Concerned Scientists,
which has been critical of the agency's handling of Bt crops, said: "We were
disappointed. It's clear that there are insufficient data."
Because studies showing actual effects of Bt corn pollen on monarch
butterfly populations in the wild are still in progress, the report relied instead
on indirect studies that, like the original Cornell research, simply indicate a
greater or lesser likelihood of risk to the monarchs from the pollen. Data
considered include the toxicity of different strains of Bt corn and the distance
that toxic pollen can move within and beyond a cornfield.
In addition to arguing against risks to monarchs, the report also disputed the
significance of other studies that had suggested the potential for unexpected
environmental threats from Bt crops. For example, some studies have
indicated that the Bt toxin from these plants can persist much longer than had
been thought possible in the soil. Other studies have indicated that pest
caterpillars that have eaten the Bt toxin can sicken the beneficial insect
predators that eat them.
In one of few concessions to critics, the report suggests that more can be
done to prevent the evolution of pests that are resistant to the Bt toxin. Bt
toxin has traditionally been sprayed on fields by farmers. The arrival of
genetically engineered Bt potatoes, corn and cotton that continually produce
Bt in their tissues raised the possibility that insects would be exposed more
often and for longer periods to the toxin. Such exposure could speed the
evolution of pests that are resistant to the insecticide, a development that
would render Bt useless. Produced naturally by a bacterium, Bt toxin is an
important insecticide for organic farmers and one of the few available for
their use.
Over the next year, Mr. Steinwand said the agency would continue to
reassess Bt crops. He said half the new research that the agency had
requested from scientists to assess the potential threat of Bt corn to
monarchs had not yet been submitted to the agency.
In just the last month, he said, the E.P.A. was surprised to learn from
researchers that monarch caterpillars could be found in the middle of
cornfields, the place where most of the toxic pollen from Bt corn plants ends
up landing.
"That told us, Hey wait a minute," said Mr. Steinwand. "We're still waiting
for a considerable amount of data."
Copyright 2000 The New York Times Company |
