Corn silk flies (Ulidiidae: Tephritoidea) are important economic pests of sweet corn due to their direct damage caused by larvae to developing ears of corn. Insecticidal control is limited due to insecticide resistance, withdrawal requirements before harvest and protection of developing larvae under corn husks. Pupation occurs either on the ground or within the husk. Several species of broad host range pupal parasitoids are effective and commercially available for control of muscoid flies. In this laboratory study three solitary parasitoid species (Muscidifurax raptor, Spalangia cameroni, Spalangia endius) and two gregarious species (Nasonia vitripennis, Muscidifurax raptorellus) were evaluated against pupae of Euxesta eluta and Chaetopsis massyla with Musca domestica as controls. All parasitoid species developed in pupae of both corn silk fly species despite these species being significantly smaller than those of M. domestica. Muscidifurax raptor and M. raptorellus produced over 85% mortality for all species, with all other species providing moderate mortality. Size of parasitoid was affected by host species for all parasitoids except for S. cameroni with E. eluta consistently producing the small parasitoids. Pupal parasitoids appear to have potential as a possible management tool for these pest species.
