辽宁朝阳市为中国北方特早熟棉区,棉花生育期只有140d左右,有时还少。常年棉花现蕾期为6月30日左右,7月20日前的棉蕾开花结铃后能在霜前吐絮,形成产量。此时如受棉铃虫为害而落蕾,会造成大幅度减产。常年第二代棉铃虫幼虫发生期在6月中旬至7月中旬,幼虫为害早蕾,对棉花产量影响 Chaoyang City, Liaoning Province, China is extremely precocious cotton area in northern China, cotton growth period of only about 140d, sometimes less. Perennial cotton budding period is about June 30, July 20 cotton boll flowering boll before the frost in order to form the production. At this point, if the cotton bollworm harm and fall buds, will result in a substantial cut. Perennial second-generation cotton bollworm larvae occur in mid-June to mid-July, larvae affect the early bud, the impact on cotton production