(Figs 21 A–C)

Corynoneura scutellata Winnertz, 1846: 13; Boesel &Winner 1980: 502; Hirvenoja & Hirvenoja 1988: 217; Schlee 1968: 40.

Material examined. CANADA, Manitoba, Lake Winnipeg: Victoria Beach, light trap, 17 males, 2 females, 9.vii. & 25.vii.1969, P.S.S. Chang; Pine Dock, light trap, 1 male, 10.vii.1969, P.S.S. Chang; 20 Mile Creek, light trap, 4 males, 26.viii.1971, N. Hooper. USA, Ohio: Knox County, Ballfield Marsh, 1 mile south of Bladensburg, 1 larval exuviae, 18.v.2001, M. Micacchion; Summit County, Steels Corners Wetland, 3 larval exuviae, 22.v.2001, M. Micacchion (ZMBN, MJB).

Larva (n = 3–4)

Coloration. Head yellowish. Antenna with basal and second segments yellowish, other segments light brown. Abdomen yellowish.

Head. Capsule length 256–272, 263 µm, width 164–172, 167 µm; strongly sculptured. Postmentum 220– 228, 223 µm long. SII obvious, rising from small tubercle, SI and SIII not visible. Premandible 18–28, 22 µm long. Mentum as in Fig. 21 B. Mandible 55–69, 61 µm long. Antenna (Fig. 21 A), AR 0.91–1.1, 1.03. Lengths of flagellomeres I–IV (in µm): 204–236, 227; 101–105, 103; 105–117, 112; 4–6, 5. Basal segment width 15–18, 17 µm; length of blade at apex of basal segment 28–35, 30 µm. Length of antenna/length of head 1.71–1.74, 1.73.

Abdomen. Length of anal setae 224–280, 245 µm. Procercus 10–12, 11 µm long, 10–12, 11 µm wide. Subbasal seta of posterior parapods split as in Fig. 21 C; 55–63, 59 µm long.

Remarks. The male is described by Schlee (1968: 40). The Lake Winnipeg specimens are slightly smaller than mentioned by Schlee, with wing length of 0.83–1.00, 0.90 (6) and wing length/length of profemur of 3.32–3.58, 3.43. Two females which may belong to this species differ from C. porrecta sp. n. by having an AR of 0.51–0.52, slightly larger size, and having about 6 lateral lamellae on the coxosternapodeme.

Distribution and ecology. The species is known in all regions except the Afrotropical region and North Africa (Oliver et al. 1990: 23; Saether & Spies 2011). Many records, however, need reexamination and Schlee (1968: 43) could only confirm findings from Finland, Germany and Austria. The reconfirmed findings are restricted to oligotrophic or, at most, mesotrophic waters. The species is characteristic for the littoral vegetation (Schlee 1968: 42).