D3543: First record of a parasitoid wasp using adult flies as hosts (Diptera: Drosophilidae and Hymenoptera: Braconidae, Euphorinae)

Parasitism of adult insects is an unusual lifestyle among parasitoid wasps, but it is common within the braconid subfamily Euphorinae. The hosts of euphorines belong to eight insect orders, including the large orders Coleoptera, Hymenoptera, Lepidoptera, and Hemiptera, but no euphorines or other wasps are known to use adult dipterans as hosts. From backyard collections in Mississippi, we report and describe a wasp in the euphorine tribe Syntretini that parasitizes adult flies in the genus Drosophila. Molecular and morphological data support a new species in the genus Syntretus, previously known only to parasitize adult bees and wasps. We characterize the life history of Syntretus perlmani sp. nov., explore its geographic distribution and host range, and outline methods to rear Syntretus wasps in the laboratory. Our results provide a remarkable example of undiscovered parasitoid biology in one of the most deeply studied laboratory insects and open new avenues of research into the ecology and infection biology of adult parasitism by euphorine wasps.