Abstract: It was confirmed that the pupae of Helicoverpa armigera needed brain in the early development stage by the experiment of brain excision. The development of diapause pupae did not need brain in the mid or later development stage. The pupal diapause in H. armigera could be terminated with the injection of active brain, and it was suggested that the activation of brain in diapause-destined H. armigera had descended since prepupal stages. The role of brain in diapause in H. armigera was discussed based on these results.

Key words: Helicoverpa armigera, diapause, brain