Fecundity and development of the ectoparasitic wasp Nasonia vitripennis are dependent on host quality

Abstract

AbstractThe gregarious, ectoparasitoid Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae) was offered pupae representing seven fly species, but only members of two families (Sarcophagidae and Muscidae) were parasitized. Host acceptance as an oviposition site did not imply host suitability for parasitoid growth: N. vitripennis produced fewer progeny, a higher proportion of males, required a longer development time, and produced smaller adult wasps on Musca domestica L. (Diptera: Muscidae) than on the three sarcophagid species tested [Sarcophaga bullata Parker, S. crassipalpis Macquart, and Peckia abnormis (Enderlein) (Diptera: Sarcophagidae)]. The physiological and nutritional status of a preferred host, S. bullata, influenced oviposition behavior and development of N. vitripennis. Progeny allocation and sex ratio, which were regulated by the female parasitoid during oviposition, differed on living and dead nondiapausing hosts and on diapausing pupae. Differences in the host's nutritional condition was reflected in changes of the wasp's development time and adult body size. Envenomation was essential for successful development of the parasitoid on nondiapausing hosts, but venom injection by N. vitripennis did not increase the suitability of diapausing or dead pupae. The results suggest that wasp development is enhanced by changes induced in the host by parasitism.