GMO Crops Creating Herbicide Resistant Beasts
Genetically modified organisms are designed to create a strong and resistant plant that can effortlessly ward off bugs. Biotech companies have produced and mass marketed several varieties of GMO to control pests, but some evidence shows that insects are evolving too quickly.
The way a genetically modified organism like Bacillus thuringiensis (Bt) – a bacterium added to plants to repel the rootworm – works is to create an environment so toxic for the insect that it cannot adapt. Theoretically, GMO crops do not, then, harm humans, as the toxin itself is bred into the plant rather than applied in a chemical spray.
But Bt is showing some limitations in how bugs are dealing with it. The herbicide isn’t working precisely the way it was engineered to. A 2011 Bt corn crop showed that the harvest was decimated by rootworm was studied for clues.
Researchers found in 2009 and 2010 that the rootworm had adapted much more quickly than would be expected, and had developed specific resistance to a Bt toxin called Cry3Bb1. In subsequent examinations of the more recent (2011) crop, more resistance had developed to a second Bt toxin mCry3A, including cross resistance between the two toxins.
The researchers also found that pests develop rapid resistance when a high enough level of Bt wasn’t used.