In some previously reported cases, transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce Bt toxins. Here we used 16 years of field data to determine if Bt cotton caused this “halo effect” against pink bollworm (Pectinophora gossypiella) in six provinces of the Yangtze River Valley of China. In this region, the percentage of cotton hectares planted with Bt cotton increased from 9% in 2000 to 94% in 2009 and 2010. We found that Bt cotton significantly decreased the population density of pink bollworm on non-Bt cotton, with net decreases of 91% for eggs and 95% for larvae on non-Bt cotton after 11 years of Bt cotton use. Insecticide sprays targeting pink bollworm and cotton bollworm (Helicoverpa armigera) decreased by 69%. Previously reported evidence of the early stages of evolution of pink bollworm resistance to Bt cotton in China has raised concerns that if unchecked, such resistance could eventually diminish or eliminate the benefits of Bt cotton. The results reported here suggest that it might be possible to find a percentage of Bt cotton lower than the current level that causes sufficient regional pest suppression and reduces the risk of resistance.
Pink bollworm abundance on non-Bt cotton before and after adoption of Bt cotton.
Volledige artikel in Plos One.
Over the past 16 years, vast plantings of transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) have helped to control several major insect pests1, 2, 3, 4, 5 and reduce the need for insecticide sprays1, 5, 6. Because broad-spectrum insecticides kill arthropod natural enemies that provide biological control of pests, the decrease in use of insecticide sprays associated with Bt crops could enhance biocontrol services7, 8, 9, 10, 11, 12. However, this hypothesis has not been tested in terms of long-term landscape-level impacts10. On the basis of data from 1990 to 2010 at 36 sites in six provinces of northern China, we show here a marked increase in abundance of three types of generalist arthropod predators (ladybirds, lacewings and spiders) and a decreased abundance of aphid pests associated with widespread adoption of Bt cotton and reduced insecticide sprays in this crop. We also found evidence that the predators might provide additional biocontrol services spilling over from Bt cotton fields onto neighbouring crops (maize, peanut and soybean). Our work extends results from general studies evaluating ecological effects of Bt crops1, 2, 3, 4, 6, 12, 13 by demonstrating that such crops can promote biocontrol services in agricultural landscapes.
Officiële website van ministerie van landbouw in China:
“Research, selling, importing and exporting of transgenic grain seeds should comply with state regulations. Any institution or individual must not apply transgenic technologies to principle grain cultivars without approval, said the draft of a law referring to transgenics, the practice of inserting into an organism DNA that is not normally present.”
“It will be impossible for transgenic corn and rice to appear on the market if their commercial production is not approved by relevant departments, Chen Xiwen, director of the Office of Central Rural Work Leading Group, said at a press briefing earlier this month.”
Greenpeace maakt daarvan:
“We’re ecstatic to announce a new legal initiative in China that’s set to keep GM away from the country’s staple food.”
“The State Council has released the draft proposal of a grain law that establishes legislation restricting research, field trials, production, sale, import and export of genetically modified grain seeds. The draft stipulates that no organization or person can employ GM technology in any major food product in China.”