THE POPULATION DYNAMICS AND INTERGRATED BT TRANSGENIC MANAGEMEAT OF HELICOVERPA ARMIGERA IN THE COTTON FIELDS

Systematic investigations and field investigatins on the Helicoverpa armigera were carried out in Bt transgenic cotton field.The results showed that there is no difference between transgenic cotton and common cotton in egg amount,but the larva amount declined obvioush in transgenic cotton.The resistance tests of Bt transgenic cotton to Helicoverpa armigera showed that the resistance varies amony different tissues and organs of cotton as well as between different insect generations.The investigation results of the distribution of Helicoverpa armigera in Bt transgenic cotton and other host plant fields suggest that other host piant fields are the main source of Helicoverpa armigera. Our experimental results demonstrated that the feasible period of the chemical management of Helicoverpa armigera should he conducted 3-5 days after the hatching peek.