The physiological effect of insect allatostatin double C (ASTCC) was characterized in Lepidoptera for the first time. ASTC and ASTCC may stimulate JH biosynthesis in larvae while inhibit JH biosynthesis in female adults. In female heads, ASTC and ASTCC may function dependently but not in tandem. Simultaneous suppression of ASTC and ASTCC increased the mortalities of larvae and pupae.