PROC. ENTOMOL. SOC. WASH. 109(1), 2007, pp. 9-16 HIGHER DIPTERA ASSOCIATED WITH THE MARSH SPIKE-RUSH, ELEOCHARIS PALUSTRIS (CYPERACEAE), IN NORTHEASTERN OHIO B. A. FooTE Department of Biological Sciences, Kent State University, Kent, Ohio 44242 (e-mail: [email protected]) Abstract. — Information is given on 28 of the 50 species of higher Diptera that were found in stands of the marsh spike-rush, Eleocharis palustris (L.) Roemer & Schultes, in northeastern Ohio. Seasonal distributions, abundances, and larval feeding habits of selected species are presented. Key Words: Eleocharis, Diptera, freshwater marshes, Ohio This is the ninth paper in a series that focuses on the species of higher Diptera (Schizophora) that occur in freshwater marshes in northeastern Ohio (Todd and Foote 1987a, b; Rogers et al. 1991; Wearsch and Foote 1994; Larson and Foote 1997; Keiper et al. 1998; Foote 2004a, b). The present study gives survey data obtained during one field season of collecting higher Diptera from a near-monoculture stand of the marsh spike-rush, Eleocharis palustris (L.) Roemer & Schultes, growing in a roadside drainage ditch near Kent in northeastern Ohio. Information is given on seasonal occur-rence and larval feeding habits of 28 of the 50 associated species. Materials and Methods Eleocharis palustris is a widespread, narrow-leaved, emergent, perennial spe-cies of Cyperaceae having horizontal, mat-forming rhizomes (Ball et al. 2002). The study stand was located in a shallow drainage ditch bordering Hodgeman Lane, a small road leading to the Kent Water Treatment Plant on the east side of the city in Portage County (41° 08' 33"N X 81° 19' 19"W). The stand was long and narrow (100 X 5 m) and consisted of a near monoculture of E. palustris, although a few individuals of rice cut grass, Leersia oryzoides (L.) Swartz, were scattered throughout the stand. The stand was bordered on either side by an undetermined species of grass and by narrow-leaved cattail (Typha angustifolia L.) at its northern end. The study site was mowed periodically by county maintenance crews throughout the summer months. Water, at a depth of some 10 cm, was present during the spring months. Water depths receded steadily as summer advanced, although summer rains caused temporary fluctua-tions. By late August, no standing water was present. Specimens of Diptera were obtained by sweep samples consisting of 15 back and forth movements of a 15 inch diameter standard aerial insect net through the stand. Sampling took place weekly for 22 weeks between 6 May and 30 Septem-ber, 2004. Nearby stands of rice cutgrass and other undetermined grass species were swept for comparative purposes. Rearings were initiated from larvae or adults collected from the host plant.