| Abstract: | This study was concerned with the role of the accessory reproductive organs of female hymenopteran parasitoids in the host-parasitoid association. These glands were found to be important in host discrimination and in the regulation of host development. The parasitoids used in this study were Cardiochiles nigriceps Viereck, Microplitis croceipes (Cresson) (Braconidae) and Campoletis sonorensis (Cameron) (Ichneumonidae). Host Discrimination The parasitoid, M. croceipes, detected parasitized Heliothis virescens (F.) larvae only after they were parasitized several times (super-parasitized). Detection of a material deposited on the host during oviposition enabled this parasitoid to discriminate against super-parasitized larvae, Dufour's gland was shown to be the source of this external ovipositonal deterrent for this parasitoid and for C. nigriceps and C. sonorensis. An additional material, isolated from the lateral oviducts of C. sonorensis, also resulted in discrimination by this parasitoid. This material was injected into the host during oviposition and discrimination during subsequent ovipositional attacks occurred only after the ovipositor was inserted into the host. ... |
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