GM crops do not harm beneficial beetles

Genetically modified plants using Bt (Bacillus thuringiensis), a common soil bacterium, to kill pests will not harm the natural enemies of pests, according to a new study by Cornell entomologist.

This is good news for ecologists and farmers in the debate about genetically modified plants. Much of the debate surrounding the use of genetically modified crops focuses on their impact on organisms that are not pests.

Research shows that genetically modified plants expressing Bt insecticidal proteins are not toxic to parasites that live inside the caterpillars of diamondback moths, a devastating vegetable in the world. This study was published in PLoS One online science magazine on July 27

Diamondback moth larvae, a devastating plant pest.Puzzle: bee parasitic Diadegma insulare, killing diamondback moth, but not hurt by Bt or Bt crops, proving that Bt does not harm beneficial organisms.(Photo: Joe Ogrodnick)

Bt bacteria, not harmful to humans, has been used for decades as a leaf spray and since 1996, used in genetically modified plants, a method proved to be more effective. Many and currently more widely used. Both uses are approved by the US Environmental Protection Agency. In 2007, Bt corn and Bt cotton plants were planted in 22 countries over 104 million acres.

To separate the effects of pesticides and Bt proteins on caterpillars and parasites, Cornell researchers isolated and raised caterpillars that were resistant to Bt or traditional or organic pesticides. Later, the caterpillars were kept parasitic with the wasps, which killed moths in nature.

This resistant caterpillar is then fed or genetically modified plants expressing Bt protein or non-GMO plants sprayed with Bt, traditional or organic pesticides.

The caterpillars are parasitic that eat traditional or organic pesticide plants that are resistant to it, live a fever and grow into moths because parasites have been killed. by insecticides that caterpillars digest. However, when caterpillars are fed with Bt or Bt plants, the parasite is unaffected and kills its host caterpillar as it grows into an adult wasps, proving that Bt objects are non-toxic to parasitic animals / plants.