Bt cotton is a genetically modified pest-resistant cotton variety that produces an insecticide to combat bollworm. It has been genetically modified by the insertion of one or more genes from a common soil bacterium, Bacillus thuringiensis. The strains of this bacterium produce over 200 different proteins, some of which are toxic to certain insects. The main selling points of Bt cotton are the reductions in pesticides to be sprayed on a crop and the ecological benefits which stem from that. Bt cotton was first planted in China in 1997 in response to an outbreak of cotton bollworm, Helicoverpa armigera, that farmers were struggling to control with conventional pesticides. Similarly, in India and the US, Bt cotton initially alleviated the issues with pests while increasing yields and delivering higher profits for farmers. However, in India, Bt cotton has been enveloped in controversies due to its supposed failure to reduce the need for pesticides and increase yield. The link between the introduction of Bt cotton to India and a surge in farmer suicides has been refuted by other studies, with decreased farmer suicides since Bt cotton.