Since 1993, Xinjiang has become the largest cotton producer among provincial administrative units in China. In the same time, the cotton bollworm, Helicoverpa armigera (Hubner), increased very rapidly and caused a serious loss in 1996. Then the autonomous government initiated a community-wide control program. Suppressing pupae, trapping moths and spraying small larvae and eggs, which were called " three Battles," were conducted in a vast area and resulted a sound control. The bollworm density was decreased to a low level and the cotton production was increased by 30% in 1997-1998.