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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #377568
Research Project: Productive Cropping Systems Based on Ecological Principles of Pest Management

Location: Integrated Cropping Systems Research

Title: New records document Cystiphora sonchi (Vallot) (Diptera: Cecidomyiidae) and associated parasitoids (Hymenoptera) in the continental United States

Author
item Hesler, Louis
item Gates, Michael
item Beckendorf, Eric

Submitted to: Insecta Mundi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/7/2020
Publication Date: 11/27/2020
Citation: Hesler, L.S., Gates, M.W., Beckendorf, E.A. 2020. New records document Cystiphora sonchi (Vallot) (Diptera: Cecidomyiidae) and associated parasitoids (Hymenoptera) in the continental United States. Insecta Mundi. 0815:1-8. https://journals.flvc.org/mundi/article/view/127291.

Interpretive Summary: A gall midge of sowthistles is reported for the first time in the continental United States from the states of Minnesota, North Dakota, and South Dakota. The gall midge mainly infests perennial sowthistle, a weed that was the impetus for earlier releases of the gall midge as a biological control in Canada. Patches of sowthistle in the three states were commonly infested with the gall midge, and often leaves were densely galled. Dissections of galled leaves led to the novel finding of multiple gall midge larvae in some individual galls. In addition, various parasitic wasps in the genera Aprostocetus, Lyrcus, and Ceraphron emerged from galls sampled in South Dakota. Further research is warranted to determine the geographic extent of the gall midge and its parasites in the USA and to determine the impact of the gall midge on its weedy hosts there.

Technical Abstract: A gall midge, Cystiphora sonchi (Vallot, 1827), is reported for the first time in the continental United States of America from the states of Minnesota, North Dakota, and South Dakota. The gall midge is an obligate parasite of perennial sowthistle, Sonchus arvensis L., a weed that was the impetus for earlier releases of C. sonchi as a biological control in Canada. Patches of S. arvensis were commonly infested with C. sonchi, and often leaves were densely galled. Dissections of galled leaves led to the novel finding of multiple C. sonchi larvae in some individual galls. In addition, two parasitoids emerged from galls sampled in South Dakota: Aprostocetus cf. atticus Graham Lyrcus poss. n. sp., and Ceraphron sp. Further research is warranted to determine the geographic extent of C. sonchi and its parasitoids in the USA, and to determine the impact of C. sonchi on its weedy hosts.