A study conducted by a team led by Aaron Gassmann, an entomologist at Iowa State University in Ames, and published in the Proceedings of the National Academy of Sciences details how genetically modified corn is no longer efficient at killing the western corn rootworm (Diabrotica virgifera virgifera):
“Beginning in 2009, western corn rootworm with resistance to maize producing the Bt toxin Cry3Bb1 imposed severe injury to Cry3Bb1 maize in Iowa. We show that cross-resistance exists between Cry3Bb1 maize and mCry3A maize and is associated with severe injury to Bt maize in farmers’ fields. These results illustrate that Bt crops producing less than a high dose of toxin against target pests may select for resistance rapidly; consequently, current approaches for managing Bt resistance should be reexamined.”
The abstract concludes, “These first cases of resistance by western corn rootworm highlight the vulnerability of Bt maize to further evolution of resistance from this pest and, more broadly, point to the potential of insects to develop resistance rapidly when Bt crops do not achieve a high dose of Bt toxin.” Gassmann warns, “Unless management practices change, it’s only going to get worse…There needs to be a fundamental change in how the technology is used.”
This has occurred because of a combination of corruption and incompetence. The EPA is a joke and today’s average farmer doesn’t really know how to farm. Rather than tend the soil and rotate crops, they just keep growing GM corn and ask the chemical company to “fix” any issue.
Wired quotes two entomologists:
Entomologist Bruce Tabashnik of the University of Arizona called Bt resistance “an increasingly serious problem,” and said that refuge sizes need to be increased dramatically and immediately. He and other scientists have pushed the EPA to double current refuge requirements, but so far without success.
“Biotech companies have successfully lobbied EPA for major reductions in refuge requirements,” said Tabashnik.
Entomologist Elson Shields of Cornell University agrees. “Resistance was caused because the farmers did not plant the required refuges and the companies did not enforce the planting of refuges,” said Shields, who has written that “a widespread increase in trait failure may be just around the corner.”
Shields also lamented the difficulty he and other academic scientists long experienced when trying to study Bt corn. Until 2010, after organized objections by entomologists at major agricultural universities forced seed companies to allow outside researchers to study Bt corn, the crop was largely off-limits. Had that not been the case, said Shields, resistance could have been detected even earlier, and perhaps stalled before it threatened to become such a problem.
“Once we had legal access, resistance was documented in a year,” Shields said. “We were seeing failures earlier but were not allowed to test for resistance.”
Corruption and incompetence.
Sources for this article:
1. Field-evolved resistance by western corn rootworm to multiple Bacillus thuringiensis toxins in transgenic maize http://www.pnas.org/content/early/2014/03/12/1317179111
2. Voracious Worm Evolves to Eat Biotech Corn Engineered to Kill It http://www.wired.com/wiredscience/2014/03/rootworm-resistance-bt-corn/
Written by Alternative Free Press
Study Confirms Genetically Modified Corn Doesn’t Work by AlternativeFreePress.com is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.