The rôle of the calyx and poison gland of Cardiochiles nigriceps in the host-parasitoid relationship

Parasitism of Heliothis virescens by Cardiochiles nigriceps reduced the growth of the host. Both the poison gland and the calyx of the female parasitoid were important in reducing the growth of the parasitized host. Injections of poison gland contents (0·04 gl/larva) or calyx fluid (0·04 gl/larva) into H. virescens larvae did not affect their growth. However, a mixture of the two glands (1:1) at this low dosage significantly reduced the weight gained by Heliothis larvae.