Widespread adoption of Bt cotton and insecticide decrease promotes biocontrol services.
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. 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 services. However, this hypothesis has not been tested in terms of long-term landscape-level impacts. 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 crops by demonstrating that such crops can promote biocontrol services in agricultural landscapes.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193 China.
Yanhui
Y
Lu
Kongming
K
Wu
Yuying
Y
Jiang
Yuyuan
Y
Guo
Nicolas
N
Desneux
D000383:Agriculture / Q000639:trends; D000818:Animals; D001042:Aphids / Q000502:physiology; D001181:Arthropods / Q000502:physiology; D001413:Bacillus thuringiensis / Q000235:genetics; D002681:China; D020387:Food Chain; D003368:Gossypium / Q000235:genetics / Q000469:parasitology; D007306:Insecticides; D010572:Pest Control, Biological / Q000639:trends*; D030821:Plants, Genetically Modified; D011156:Population Density; D013997:Time Factors
D007306:Insecticides