Corynoneura lobata Edwards

Fu, Yue & Saether, Ole A., 2012, 3536, Zootaxa 3536, pp. 1-61 : 35-38

Corynoneura lobata Edwards

( Figs 17 A–E)

Corynoneura lobata Edwards, 1924: 186 ; Tokunaga 1936: 42; Schlee 1968: 43; Cranston & Oliver 1988: 430; Sasa 1988: 56; Sasa & Suzuki 1998: 17; Sasa & Suzuki 1999: 106; Epler 2001: 7.48; Bolton 2007: 27; Fu et al. 2009: 23 .

Corynoneura oxfordana Boesel et Winner, 1980: 505 , syn. n.

? Corynoneura sp. C Epler, 2001 : 7.46

? Corynoneura sp. G Epler, 2001 : 7.47

Material examined. USA: Minnesota, Miller Creek, 1 mile west of Lake City , 3 males, 1.x.1972 and 25.iii.1973, P.L. Hudson ; Ohio, Oxford, 1 male, holotype of C. oxfordana (NO. YPM ENTO 500000 ), 8.xi.1978, R.W. Winner ; 1 female, allotype (NO. YPM ENTO 500001 ) and paratypes (8 males and 7 females) of C. oxfordana , as holotype except for 7.xi.1978 and 3.xi.1978 ; Ohio, Highland County, Rocky Fork , 1 male, 1 pupal and 1 larval exuviae, 30.ix.1986, M.J. Bolton ; Ohio, Delaware County, Olentangy River upstream of Hyatts Rd. , 2 females, 2 pupal and 2 larval exuviae, 31.vii.1986, M.J. Bolton ; Ohio, Summit County, Sand Run Park , spring-stream, 2 males, 1 female, 3 pupal and 3 larval exuviae, 12.iv.1987, M.J. Bolton . CANADA: Alberta, Bigoray River , 2 males, 21.v.1973, H. Boerger ; Manitoba, Lake Winnipeg: Victoria Beach , light trap, 1 male, 9.vii.1969, P.S.S. Chang; Grand Rapids Government Wharf, light trap, 1 male, 28.vii.1969, P.S.S. Chang; McBeth Harbour, light trap, 1 male, 7.ix.1969, P.S.S. Chang; Beaver Point, light trap, 1 male, 25.vi.1971, E. Johnson & S. Flam; Calder's Dock, light trap, 2 males, 28.vii. & 31.viii.1971, Freshwater Institute L. Winnipeg project; Calder's Dock, rearing samples, 12 males, 4 females, 30.vi.–17.viii.1971, Freshwater Institute L. Winnipeg project ( ZMBN, MJB, JHE) .

Diagnostic characters. The males from Lake Winnipeg fit well the redescription by Schlee (1968: 43). The female has WL of 0.64–0.72 mm, only 4–6 dorsocentrals, 48–55 µm long anapleural suture, 1 seta on gonocoxite IX, 4 on tergite IX and coxosternapodeme with 7–8 lateral lamellae. The pupa is 1.6–1.8 mm long, has no taeniate L-setae on tergite I and only one on II, and 31–36 taeniae in fringe of anal lobe. The larvae are separable by AR 1.0–1.1, mentum with three median tooth, with the central tooth shorter than the lateral median one; the first lateral teeth smaller than the adjacent teeth; head capsule sculptured by reticulate pattern. The holotype of C. oxfordana has an antenna with 10 flagellomeres while the original description mentions 11 flagellomeres. The males fit well the redescription by Schlee (1968: 43).

Female (n = 2–3)

Total length 0.95–1.17 mm. Wing length 0.64–0.72 mm. Total length/wing length 1.47–1.63. Wing length/ profemur length 3.62.

Head. AR 0.32–0.36. Flagellomeres length (in µm): 33–36, 28–32, 26–32, 24–36, 37–45. Temporals absent. Clypeus with 8 setae. Tentorium 56–74 µm long. Stipes 40–64 µm long. Palp lengths (in µm): 10, 13–14, 18–22, 24–28, 44–51.

Thorax. Antepronotum with 1 seta. Dorsocentrals 4–6, prealars 2. Scutellum with 2 setae. Anapleural suture 48–55 µm long.

Wing. VR 2.50–2.83, C 282–337 µm long, C/wing length 0.44–0.47, Cu/wing length 0.57–0.59. Brachiolum with 1 seta.

Legs. Fore trochanter with distinct dorsal keel. Spur of fore tibia 12–14 µm, spurs of mid tibia 14 and 6–9 µm, of hind tibia 28–35 and 7–10 µm. Width at apex of fore tibia 18 µm, of mid tibia 16–20 µm, of hind tibia (a) 29–38 µm. Width of hind tibia 1 / 3 from apex (d) 19–20 µm, elongation length (b) 33–40 µm, length of maximum thickening (c 1) 52–60 µm, total length of thickening (c 2) 73–86 µm, a/d 1.53–1.90, b/d 1.65–2.11, c 1 /d 2.70–3.16, c 2 /d 3.80–4.53. Hind tibia expanded, with comb of 14–15 setae, shortest seta 14–18 µm, longest seta 20–24 µm. Sensilla chaetica absent. Lengths of leg segments and their proportions as in Table 16.

Genitalia ( Fig. 17 A). Cercus 22–36 µm long. Gonocoxite IX with 1 seta. Tergite IX with 4 setae. Notum 44– 60 µm long. Coxosternapodeme with 7–8 lateral lamellae. Seminal capsule 42–50 µm long, 33–40 µm wide. Pupa (n = 3–4)

Total length 1.64–1.79, 1.72 mm (4). Exuviae pale, transparent with pale greyish yellow thorax.

Cephalothorax. Third precorneal seta (PcS 3) 28–34 µm (3) long. PcS 1–3 in a line; PcS 1 4–6, 5 µm (4) from PcS 2; PcS 2 3–6, 4 µm (4) from PcS 3. Frontal setae taeniate, 36–48 µm (3) long. Po 2, taeniate, 52–80, 66 µm (4) long. Second dorsocentral (Dc 2) 10–24 µm (2) long, Dc 3 50–52 µm (2) long, Dc 4 26–30 µm (3) long. Dc l located 8–10 µm (3) from Dc 2, Dc 2 located 56–98 µm (3) from Dc 3, Dc 3 located 14 (1) µm from Dc 4.

Abdomen ( Fig. 17 B). Shagreen and chaetotaxy as illustrated. No taeniate L-setae on I, only 1 on II. PSA and PSB absent. Anal lobe with 31–36, 33 (4) setae in fringe; all taeniate, not hooked apically, about 200 µm long. Median setae taeniate 80–140, 97 µm (4) long. Larva (n = 3–6)

Coloration. Head yellowish. Antenna with basal segment almost transparent, other segments yellowish. Abdomen yellowish.

Head. Capsule length 256–260, 259 µm, width 172–184, 179 µm; sculptured by reticulate pattern. Postmentum 220–228, 223 µm long. SII large, SI and SIII not visible. Premandible 28–32, 30 µm long, brush of premandible not observed. Mentum as in Fig. 17 E. Mandibles 48–55, 52 µm long. Antenna as in Fig. 17 D, AR 1.0–1.1. Lengths of flagellomeres I–IV (in µm): 156–178, 165; 50–55, 52; 104–110, 106; 3–6, 4. Basal segment width 14–17 µm; length of blade at apex of basal segment 35–38, 36 µm; ring organ at 76–90, 82 µm from the base of antenna.

Abdomen. Length of anal setae 131–140, 135 µm. Procercus 10–13, 12 µm long, 7–8 µm wide. Subbasal seta of posterior parapods split as in Fig. 17 C.

Distribution and ecology. The species is known from rivers, streams and springs in the Holarctic Region including North Africa and the Far East, and also from the Near East ( Oliver et al. 1990: 22, Saether & Spies 2011). The species has early spring and fall emergence periods, however, with some scattered individuals occurring throughout the summer months ( Schlee 1968: 47).