Food, Inc. by Peter Pringle

Author:Peter Pringle
Language: eng
Format: epub, pdf
Publisher: Simon & Schuster
Published: 2003-08-20T16:00:00+00:00

7 ANATOMY OF A POISONED BUTTERFLY

It’s not an exaggeration to say more monarchs succumb to high-velocity collisions with car windshields than ever encounter corn pollen.

—VAL GIDDINGS, BIOTECHNOLOGY INDUSTRY ORGANIZATION, 1999

We worked very hard to make this a high-profile issue…. The question still remains, would this science have been done if the monarch wasn’t such a beautiful butterfly?

—MARGARET MELLON, UNION OF CONCERNED SCIENTISTS, 2001

On the question of endangered species, most people cannot get worked up about the snail darter, the dwarf wedgemussel, or the oval pigtoe. Mention the possibility that the hairy rattleweed or the mat-forming quillwort is stressed out and a hiking club somewhere might be moved to protest. But suggest that the life of the common and beloved monarch butterfly might be at risk from human hands and a whole nation starts making posters.

The brilliance of an American summer would indeed be dimmed without the gaudy orange-and-black creatures dipping and diving in the meadows. The richness of an American fall would certainly be dulled without the monarch’s wondrous southern migration, an incredible journey during which tens of millions of creatures fly eighty miles a day to spend the winter in a Mexican forest roost. So the news that big agriculture might be killing off the royalty of American insects had all the makings of a biodisaster.

In the spring of 1999, as the monarchs embarked on their return flight north, a young Cornell University entomologist named John Losey reported in the journal Nature that the monarch’s future appeared to be endangered, not from urban sprawl or toxic waste but from eating the pollen of genetically modified corn. At the time twenty million acres of American farmland, representing a quarter of the U.S. corn crop, had been planted with seeds that included a toxin-producing gene from the common soil bacterium, Bacillus thuringiensis or Bt. The insect-poisoning power of Bt had been known for over a century; the first commercial spray was developed in Europe during World War II. Half a century later there were 182 Bt products registered by the EPA.1

Two other big crops—cotton and potatoes—had also been fitted out with the Bt gene. In corn the Bt toxin was designed primarily to kill the European corn borer, a caterpillar that destroys more than $1 billion worth of the crop each year. The toxin punctures the delicate membranes of the corn borer’s digestive tract, causing it to wither and die.

Most of the monarchs born in the Midwest corn belt start life on a milkweed leaf in or around the edges of a farmer’s land.2 When the corn sheds its pollen during July and August, pollen grains containing the Bt toxin are blown by the wind onto milkweed leaves. From earlier studies, Losey knew that Bt toxin could harm butterflies and moths, and he wondered if the monarch larvae might also suffer.

In a no-frills experiment, he fed monarch larvae with Bt pollen in his laboratory at Cornell. If they showed signs of harm, he intended to do more research in the field.

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