YORK - May 18 - A study to be published in the May 20, 1999, Nature magazine
finds that pollen from genetically engineered corn plants is toxic to monarch
butterflies. The corn was genetically engineered to contain a toxin from the bacterium
Bacillus thuringiensis (Bt). In 1998, almost 20% of US corn acreage was planted
with Bt corn as a means to control insects, and acreage is expected to increase
"Bt corn is engineered
to contain a pesticide throughout the plant," said Dr. Rebecca Goldburg, an Environmental
Defense Fund senior scientist. "Today's Nature study clearly demonstrates
that the pesticide in Bt corn is dispersed with pollen, killing monarch butterflies."
Corn plants produce huge
quantities of pollen, which dusts the leaves of plants growing near corn fields.
The Nature study found that close to half the monarch caterpillars that
fed on milkweed leaves dusted with Bt corn pollen died. Surviving caterpillars
were about half the size of caterpillars that fed on leaves dusted with pollen
from non-engineered corn.
"For too long genetic engineering
has been presented to the public as a 'safe' alternative to traditional pesticide
spraying, but genetically engineered crops are really just being used as a new
means to disseminate chemical pesticides. Monarchs that feed on pollen covered
milkweed near Bt corn fields might as well be eating pesticide sprayed milkweeds,"
said Goldburg. "Either way the result is dead butterflies."
Monarch butterflies are
noted for their remarkable annual migration, which takes them from central Mexico
in the winter to as far north as Minnesota in the summer. In the summer months,
the Midwestern corn belt is home to about half the US population of monarch butterflies.
"It would be tragic if
genetically engineered crops decimated populations of monarch butterflies similar
to the way that DDT decimated populations of bald eagles and other birds," said
Goldburg. "The Environmental Protection Agency (EPA), which regulates pesticides,
must take action to protect monarchs from poisoning by Bt corn. We urge that the
EPA severely restrict farm acreage planted in Bt corn unless and until a plan
can be developed to protect butterflies."
The Environmental Defense
Fund, a leading national, NY-based nonprofit organization, represents 300,000
members. EDF links science, economics, and law to create innovative, equitable,
and economically viable solutions to today's environmental problems.