UK Daily Mail 
December 29, 2011
One of America’s most widely planted crops – a genetically engineered corn plant that makes its own insecticide – may be losing its effectiveness because a major pest appears to be developing resistance more quickly than scientists expected.
The U.S. food supply is not in any immediate danger because the problem remains isolated. But scientists fear potentially risky farming practices could be blunting the hybrid’s sophisticated weaponry.
If rootworms do become resistant to Bt corn, it ‘could become the most economically damaging example of insect resistance to a genetically modified crop in the U.S.,’ said Bruce Tabashnik, an entomologist at the University of Arizona. ‘It’s a pest of great economic significance – a billion-dollar pest.’
When it was introduced in 2003, so-called Bt corn seemed like the answer to farmers’ dreams: It would allow growers to bring in bountiful harvests using fewer chemicals because the corn naturally produces a toxin that poisons western corn rootworms.