Killer Corn.Scientists thought they had a winner when they developed pest-killing corn. Transgenic, or genetically altered, corn was approved four years ago by the U.S. Department of Agriculture to kill the European corn pest, a moth that ravages rav·age v. rav·aged, rav·ag·ing, rav·ages v.tr. 1. To bring heavy destruction on; devastate: A tornado ravaged the town. 2. the growing crop. But it turns out the designer corn, called Bt corn, may be fatal to millions of monarch butterflies as well. Bt corn carries a gene from the bacterium Bacillus bacillus (bəsĭl`əs), any rod-shaped bacterium or, more particularly, a rod-shaped bacterium of the genus Bacillus. Some bacterium in the genus cause disease, for example B. thuringiensis (ba-SIL-us thur-in-JEAN-sis). The microbe's gene causes plant cells to manufacture Bt toxin, which is fatal to the ravenous moth that destroys nearly 40 million tons of corn each year in the U.S. Scientists at Cornell University Cornell University, mainly at Ithaca, N.Y.; with land-grant, state, and private support; coeducational; chartered 1865, opened 1868. It was named for Ezra Cornell, who donated $500,000 and a tract of land. With the help of state senator Andrew D. in Ithaca, New York
For other places or objects named Ithaca, see Ithaca (disambiguation). , recently fed monarch caterpillars milkweed milkweed, common name for members of the Asclepiadaceae, a family of mostly perennial herbs and shrubs characterized by milky sap, a tuft of silky hairs attached to the seed (for wind distribution), and (usually) a climbing habit. plant leaves dusted with Bt-corn pollen, yellow powder that contains the plant's reproductive cells. Since corn is pollinated by wind, its pollen often lands on milkweed growing right by cornfields. Milkweed is the only food monarch caterpillars eat to survive. Half the monarch caterpillars that consumed Bt-corn pollen died, while all the caterpillars who ate milkweed sprinkled with normal corn pollen lived. Though not an endangered species endangered species, any plant or animal species whose ability to survive and reproduce has been jeopardized by human activities. In 1999 the U.S. government, in accordance with the U.S. , beautiful orange-and-black monarch butterflies may be dangerously threatened by Bt corn. Much of the U.S. corn belt Corn Belt, major agricultural region of the U.S. Midwest where corn acreage once exceeded that of any other crop. It is now commonly called the Feed Grains and Livestock Belt. lies in the Midwest, the heart of monarchs, breeding range. Haft of all monarch caterpillars batch here--exactly when corn plants shed their pollen. Since other butterflies and moths feed near cornfields, they too may be in danger of Bt-corn poisoning. Studies have shown that Bt corn is safe for humans to eat and harmless to honeybees, ladybugs, and other beneficial insects. The crop is currently planted on nearly 20 million acres out of a total 80 million acres of U.S. cornfields. How much actual danger does this killer corn pose to monarchs and other insects? "We won't know until we do more research," says John Losey, a Cornell entomologist (bug scientist) who headed the study. "Then we need to weigh the risks against the benefits of this new technology." Meanwhile, monarchs better fly away from designer corn. |
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