棉田与玉米田棉铃虫(Helicoverpa armigera Hübner)种群动态特征的比较

Comparison of population dynamics of Helicoverpa armigera (Hübner) in cotton and corn fields

1998年在江苏丰县系统调查了棉田和玉米田中第三、四代棉铃虫的种群动态 ,用生命表方法比较了两种寄主田内棉铃虫种群的发育速率和存活率。结果表明 ,棉铃虫卵峰期至 4龄幼虫高峰期的历期在玉米田要比棉田快 4 d,并以产卵于玉米抽雄扬花期的发育最快。两类寄主田内平均存活率无显著差异 ,但产卵于玉米抽雄扬花期时 ,其卵至 6龄幼虫的存活率比产在其它阶段玉米上的存活率高。在江苏棉区目前的作物布局和耕作制度下 ,玉米田第三代棉铃虫是棉田第四代棉铃虫的重要虫源。

The population dynamics of the 3rd and 4th generations of Helicoverpa armigera in both cotton and corn fields were surveyed systematically at Fengxian County, Jiangsu Province, in 1998. And their survival and development rates were compared by means of life table method. It was indicated that the life span from egg to the 4th instar of the 3rd generation was 4d shorter in corn fields than in cotton fields and most rapidly development occurred when their eggs were laid during the male heading stage of corn, and that there was no significant difference of their mean larvae survival between the two kinds of host plant fields. But more larvae would survive when they were feeding on the male heading stage corn. So the population of the 3rd generation in corn fields would be an important resource of the 4th generation in cotton fields under the current cropping system in Jiangsu Province.