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 pests and reduce the need for insecticide sprays. Today, a report in Nature shows that planting of BT crops is also associated with an increase of ladybirds, lacewings and spiders, which are natural enemies of certain pests that harm the crop.
On the basis of data collected from 1990 to 2010 at 36 sites in six provinces of northern China, the authors show a marked increase in abundance in these three arthropods and fewer aphid pests. They also found benefits not only in cotton fields but also in neighbouring maize, peanut and soybean crops. This work extends the knowledge of the beneficial ecological effects of Bt crops on farm ecosystems.. These findings indicate that transgenic crops can promote biological control, and enhance sustainable management of pest populations.