ENVIRONMENTALISTS might one day run barefooted through insect-rich fields of genetically modified crops. At least, they might if the conclusions of a two-decade study in China hold up.
Kongming Wu of the Chinese Academy of Agricultural Sciences in Beijing and colleagues looked at the impact on surrounding farms of Bt cotton, a GM crop that protects itself against bollworm larvae by making its own pesticide. Without pesticide sprays, beneficial predator insects such as ladybirds, spiders and lacewings could thrive and spill over onto neighbouring farms, where they ate aphids. This reduced the amount of pesticides neighbouring farmers used (Nature, ).
鈥淔armers of the GM cotton no longer needed to use pesticides, so beneficial predator insects thrived鈥�
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鈥淭ransgenic Bt crops with less insecticide use can promote population increases of predators in the whole agricultural landscape,鈥� says Wu.
Protesters in the UK recently threatened to disrupt a trial at Rothamsted Research in Harpenden of a GM wheat that gives off a scent repelling aphids. Rothamsted鈥檚 John Pickett said the Chinese research is exciting because it shows that certain GM crops can spread beneficial insects to neighbouring farms.
But the Soil Association, which represents organic farmers in the UK, says data from the same Bt cotton study shows that new insect pests may emerge (Science, ).