Host-age effects and the efficiency of the pupal parasitoid Dirhinus giffardii (Silvestri, 1913) (Hymenoptera: Chalcididae) against the melon fly Bactrocera cucurbitae (Coquillett, 1849) (Diptera: Tephritidae)

Abstract Dirhinus giffardii is an efficient and aggressive pupal parasitoid of tephritid flies, including Bactrocera cucurbitae. Here we report on the various biological aspects of Dirhinus giffardii, mainly host-age preference, potential as well as the survival of this parasitoid from the pupae of different ages and its in vivo release against Bactrocera cucurbitae. The emergence rate of parasitoids was higher in old pupae than in fresh pupae. Similarly, the lifespan and potential of parasitoids emerged from older pupae were higher than those emerged from younger ones. The parasitoids reared on older pupae significantly controlled melon fly infestation in vivo. These findings suggest that parasitoids reared on older pupae of B. cucurbitae have a greater potential regarding fecundity, parasitism performance and survival, as these parasitoids effectively suppressed populations of B. cucurbitae under greenhouse conditions.