Trouble on the Horizon for GM Crops?
uanews.org
Caterpillars of the cotton bollworm, Helicoverpa armigera, feed on many different plants and pose a serious threat to cotton farming. (Photo by Gyorgy Csoka)
Pests are adapting to genetically modified crops in unexpected ways, researchers have discovered. The findings underscore the importance of closely monitoring and countering pest resistance to biotech crops.
Resistance of cotton bollworm to insect-killing cotton plants involves more diverse genetic changes than expected, an international research team reports in the journal Proceedings of the National Academy of Sciences.
To decrease sprays of broad-spectrum insecticides, which can harm animals other than the target pests, cotton and corn have been genetically engineered to produce toxins derived from the bacterium Bacillus thuringiensis, or Bt.
Bt toxins kill certain insect pests but are harmless to most other creatures including people. These environmentally friendly toxins have been used for decades in sprays by organic growers and since 1996 in engineered Bt crops by mainstream farmers.
Over time, scientists have learned, initially rare genetic mutations that confer resistance to Bt toxins are becoming more common as a growing number of pest populations adapt to Bt crops.