Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2022
Publication Date: 10/28/2022
Citation: Allan, S.A., Geden, C.J., Sobel, J.L. 2022. Laboratory evaluation of pupal parasitoids for control of the cornsilk fly species, Chaetopsis massyla and Euxesta eluta. Insects. 13(11): 990. https://doi.org/10.3390/insects13110990.
DOI: https://doi.org/10.3390/insects13110990

Interpretive Summary: Cornsilk flies are serious pests of sweet corn through damage caused to cobs by larval feeding and the establishment of secondary fungal infections. Control through use of pesticides is challenging due to difficulty in timing of application and delivery to immatures within the cob or underground. Recent evidence of pesticide resistance further complicates control efforts. In this study, scientists at the USDA-ARS in Gainesville, Florida and a collaborator at the University of Florida examined the potential for parasitoid wasps for biological control of cornsilk fly immatures.Two species of gregarious parasitoids and three species of solitary parasitoids were evaluated against two species of cornsilk flies and house flies as controls. All species of parasitoids were effective against the cornsilk flies and these commercially available biological control agents have potential for use in an integrated management program against cornsilk flies.

Technical Abstract: Cornsilk flies are serious pests of sweet corn through production of damage to cobs and secondary fungal establishment. As pupae are generally outside the infested cob on the ground, there is potential for use of pupal parasitoids for control. Two species of gregarious parasitoids, Muscidifurax raptorellus and Nasonia vitripennis, and three species of solitary parasitoids, Spalangia endius, Spalangia cameroni and Muscidifurax raptor, were selected for evaluation against pupae of the two cornsilk fly species, Euxesta eluta and Chaetopsis massyla. House fly pupae, the most common host for most of the parasitoids, were included for comparison. All of the parasitoids killed and successfully parasitized pupae of the two cornsilk fly species at rates that were similar to house fly pupae. Adult parasitoids that emerged from cornsilk fly hosts were somewhat smaller than parasitoids reared from house flies and had proportionally fewer females. These parasitoids, which are widely and commercially available for filth fly control, warrant further consideration for their potential against cornsilk flies in the field.