Scientists Confirm Pests Can Develop Resistance to Bt Crops...
Posted Feb 03 2010 12:00am
Scientists Confirm Pests Can Develop Resistance to Bt Crops
Scientists who have reviewed resistance monitoring data in 41 studies from five continents have found that after more than a decade since initial commercialization of Bt crops, while most target pest populations remain susceptible, field-evolved resistance to the Bt toxin has been documented in some populations of moth species in Puerto Rico, South Africa and the southeastern US.
This confirms earlier predictions that resistance can develop among the target pests that Bt crops aim to kill, and questions the touted benefits of such crops ie. that they allow farmers to save money and lessen environmental impacts by reducing insecticide sprays.
It was also highlighted that growing non-Bt crops near the Bt crops (the refuge strategy) can slow the evolution of insect resistance by increasing the chances of resistant insects mating with non-resistant ones, resulting in non-resistant offspring.
Monsanto, the company which dominates Bt crop production, conceded that the South African and Puerto Rican incidents were evidence of field-developed resistance but disputed that such a problem exists in the Southeast United States.
The findings by the scientists are published in the December 2009 issue of the Journal of Economic Entomology. The full article is available at http://www.entsoc.org/btcrops.pdf
Scientists who have reviewed resistance monitoring data in 41 studies from five continents have found that after more than a decade since initial commercialization of Bt crops, while most target pest populations remain susceptible, field-evolved resistance to the Bt toxin has been documented in some populations of moth species in Puerto Rico, South Africa and the southeastern US.
This confirms earlier predictions that resistance can develop among the target pests that Bt crops aim to kill, and questions the touted benefits of such crops ie. that they allow farmers to save money and lessen environmental impacts by reducing insecticide sprays.
It was also highlighted that growing non-Bt crops near the Bt crops (the refuge strategy) can slow the evolution of insect resistance by increasing the chances of resistant insects mating with non-resistant ones, resulting in non-resistant offspring.
Monsanto, the company which dominates Bt crop production, conceded that the South African and Puerto Rican incidents were evidence of field-developed resistance but disputed that such a problem exists in the Southeast United States.
The findings by the scientists are published in the December 2009 issue of the Journal of Economic Entomology. The full article is available at http://www.entsoc.org/btcrops.pdf