New study shows that transgenic plants don't hurt beneficial bugs
According to a new study published by entomologists at Cornell University, genetically modified (GM) plants that use Bt (Bacillus thuringiensis) to kill pests won't harm the pests' natural enemies. The study claims the Bt insecticidal proteins are not toxic to a parasite that lives inside the caterpillar of the diamondback moth, a devastating worldwide vegetable pest. Read more about this study below.
C.S. Prakash
New study shows that transgenic plants don't hurt beneficial bugs
Physorg.com
June 3, 2008
Genetically modified (GM) plants that use Bt (Bacillus thuringiensis), a common soil bacterium, to kill pests won't harm the pests' natural enemies, according to new research by Cornell entomologists.
That is welcome news for ecologists and farmers in the debate over GM plants. Much of the debate surrounding the use of GM crops focuses on their effect on organisms that aren't pests.
The research showed that GM plants expressing Bt insecticidal proteins are not toxic to a parasite that lives inside the caterpillar of the diamondback moth, a devastating worldwide vegetable pest. It was published in the May 27 issue of the online scientific journal PLoS One.
"The conservation of parasites is important for enhancing natural biocontrol that will help suppress pest populations as well as reduce the potential for the pest insects to develop resistance to the Bt," explained Anthony Shelton, Cornell professor of entomology at the New York State Agricultural Experiment Station in Geneva, N.Y., who conducted the study with postdoctoral associate Mao Chen. "Our studies make it clear that Bt plants are a win-win situation to control pest insects and to enhance biocontrol and biodiversity."
The Bt bacterium, which is not harmful to humans, has been used for decades as a leaf spray and since 1996, in GM plants, a method that has proven much more effective and is now more widely used. Both uses are approved by the U.S. Environmental Protection Agency. In 2007, Bt corn and cotton plants were grown in 22 countries on 104 million acres, according to Shelton.
"Few studies have examined the effect of Bt plants on parasites of caterpillars, but some of them have reported negative impacts," said Chen, noting that the new research suggests that those negative findings were likely due to testing methods.
