Pest adapts to GM crops

FEBRUARY 9, 2008óBollworms in cotton fields in Mississippi and Arkansas have genetically mutated to resist a toxin biotechnologists inserted into cotton crops, researchers at the University of Arizona found.

In a study of six pests in genetically modified cotton and corn in Australia, China, Spain and the United States, researchers discovered genetic adaptation in only the bollworms in a dozen fields in the United States.

The toxin inserted into the cotton plant is a common bacterium called Bacillus thuringiensis or Bt. The bollworms have become resistant to the Bt toxin strain Cry1Ac.

“What we’re seeing is evolution in action,” lead researcher Bruce Tabashnik told Terra Daily. “This is the first documented case of field-evolved resistance to a Bt crop.”

Published in the British journal Nature Biotechnology, the study found that the other five pests studied continue to be susceptible to Bt.

“The resistance occurred in one particular pest in one part of the U.S.,” Tabashnik told Terra Daily. “The other major pests attacking Bt crops have not evolved resistance. And even most bollworm populations have not evolved resistance.”

Bollworm evolution happened more rapidly in fields where there were few or no non-genetically modified plants nearby. Without non-resistant bollworms in the area, the opportunities for a resistant bollworms to mate with a non-resistant bollworms to create hybrid, non-resistant bollworms were diminished, thus speeding adaptation to the toxin among bollworms. In most pests, both parents must be resistant to the toxin in order for the offspring to inherit resistance.

By Care2 editorial staff


Melissah Chadwick
Past Member 5 years ago


Neil A.
Neil A5 years ago

Do not fight nature work with it in a natural way, also stop the chemical warfare, nature will bite back sooner or later.

Sue Matheson
Sue Matheson5 years ago


Lydia Price

It's really amazing how quickly nature adapts. I saw a documentary where they said the same thing happened with potato crop pests. It doesn't take very long. People think they can conquer nature but they can't. We need to coexist with it.

Lynn C.
Lynn C6 years ago

No surprise with this one.

K s Goh
KS Goh6 years ago

Thanks for the article.

Brenda Towers
Brenda Towers6 years ago

Nature will fight back against our interference!

Ian Donelson
Ian Donelson6 years ago

Well people are still hungry and cold, in fact rising and now nature the ultimate bio-engineer has gotten around our own ignorant tampering. Guess this idea was a failure. Time to stop Genetically Altering things and better start nurturing. It was a good run though.

Bon L.
Bon L6 years ago

Thanks for the info.

Robert O.
Robert O7 years ago

Uh-oh. Thanks.