Comparison of population dynamics of Helicoverpa armigera(Hübner) in cotton and corn fields
棉田与玉米田棉铃虫(Helicoverpa armigera Hübner)种群动态特征的比较

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.