Word: pollens
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Dates: during 1990-1999
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...study published in Nature, Cornell entomologist John Losey and his colleagues reported that pollen from corn made pest-resistant by the addition of bacterial genes could spell trouble for monarchs. In his experiments, Losey scattered pollen from the genetically modified corn onto milkweed--the butterfly's only food during its larval or caterpillar stage--and watched what happened with alarm. Most of the caterpillars that ate these leaves either died or were stunted...
With hundreds of millions of dollars at stake, agritech companies aren't eager to draw sweeping conclusions from the Cornell experiments. "Obviously the work is preliminary and inconclusive," says Monsanto spokesman Randy Krotz, minimizing the possibility that corn pollen could ever be blown far enough to affect monarch habitats. But it was just such a discovery--of pollen-dusted milkweed 200 ft. from the edge of cornfields--that prompted Losey's study in the first place. Says he: "We asked ourselves, 'What would happen if the milkweed would be dusted with Bt [corn pollen]?'" His experiments quickly gave an answer...
Losey is eager to take the experiments into the field, to measure pollen density at various distances from its source so as to determine risk to monarch larvae at each site. Says Losey: "We have to weigh the costs and benefits [of Bt corn], then decide as a society what we want." But that decision may already have been made. The Bt gene is now regularly spliced into potatoes (as protection against the Colorado potato beetle) and cotton (against the boll weevil...
...corn was thought to be very good, since it produced a natural toxin that killed corn borers, and allowed farmers to forgo the use of insecticides. On Thursday, however, a Cornell University laboratory study published in the journal Nature announced some bad news: The corn produces a wind-borne pollen that can kill monarch butterflies if they ingest it. As for the future of genetically engineered crops, the finding has raised concern, but scientists are not yet ready to sound the alarm bell full blast...
...There will always be problems of unintended consequences," says TIME senior science reporter David Bjerklie. The issue now is to find out through field research how significant those consequences are. For instance, how far can the pollen travel from a cornfield? Can it travel far enough to nearby fields of milkweed, the monarch?s food source, in significantly harmful quantities? Some other questions: Does the pollen travel during the same period that the monarchs feed on the milkweed? How much milkweed is near cornfields as opposed to other areas? And can Bt corn be modified further? Clearly the Cornell study...