The way in which nutritional resources are allocated to egg production and survival has important consequences for the predictions of many models of parasitoid behaviour and population dynamics, as well as for the outcome of biological control efforts. Using radioactively labelled amino acids, we quantified the incorporation of nutritional resources into the eggs of the host feeding parasitoid Dinarmus basalis. Our experiments show that although 40% of the nutrients acquired from a single adult meal are invested into egg production within 4 days, the rest are stored and used gradually throughout the life of the parasitoid. We also present information, obtained using a double marking technique, about the way in which parasitoids invest the resources accumulated during their larval development. We show conclusively that larval reserves constitute a significant nutritional resource for egg production in parasitoids, which is managed separately from the nutrients obtained from the adult. We discuss the relative importance of larval vs adult food sources in the light of differences in life history parameters.

Index terms: Dinarmus basalis, synovigenic parasitoids, egg production, radioactive labelling, larval reserves

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