Bt genes (there are many slightly different ones) have also been used to protect cotton from cotton boll worm. The boll worm is a devastating pest (upper pictures) and frequent applications of pesticide are required to control it. Bt cotton (lower panels) is resistant to the boll worm, reducing the necessity for pesticide. The rapid adoption of Bt cotton in many countries, including India, has resulted in both greater yields (because insect damage reduces yield) and a substantial reduction in pesticide use.