Parameletus chelifer Bengtsson 1908

Parameletus chelifer Bengtsson 1908

(Figs. 16–23)

Eatonia borealis Bengtsson, 1904:131, nomen nudum. Parameletus chelifer Bengtsson, 1908:242. Sparrea norvegica Esben-Petersen, 1909:554. Potameis elegans Bengtsson, 1909:15.

Palmenia fennica Aro, 1910:31.

Material examined. RUSSIA. Southern Yakutia: Ungra River Basin, Yuhktinka stream, mouth, light tributary of Yuhkta River, 30.VII 2006, T. Tiunova, 14 male imagines, 3 female imagines. Amurskaya Oblast’: Zeya Reservoir’s Basin, Artemii River, 50 m lower motor-car bridge, line Zeya-Verhknezeisk Town, 21.VI 2004, T Tiunova, 17 larvae; Zeya Reservoir’s Basin, Giluy River, near river crossing, 19.VI 2004, T Tiunova, 1 male imago (reared from nymph); Amur River Basin, upper part of Talali River, 25.VIII 2004, T Tiunova, 20 male imagines, 13 female imagines. Khabarovskiy Kray: Priochot’e, Ul’ya River Basin, Khetana River, 7 km upper mouth, 22.VII 1985, V Zherikhin, 1 male imago; same place, 11–17.VIII 1985. V Zherikhin, 5 male imagines, 6 female imagines; Ayano-Majskiy Region, Ujka River Basin, stream, 300 m upper mouth, left tributary of Uika River, near airport, 23.VII 1989, T Tiunova, 6 male imagines (reared from nymph). Primorskiy Kray: Ussuri River Basin, Otkosnaya River, left tributary of Ussuri River, lower motor-car bridge, 16.VI 1998, T Tiunova, 1 male imago.

Male imago. Dimensions: length (mm): body 12.8–15.0; fore wings 12.0–13.1; cerci 17.2–22.4. Total color of living imago dark brown. Head: upper portion of eyes light brown or light gray. Thorax: medioscutum and submedioscutum brown; sublateroscutum and posterior scutal protuberance dark brown (Fig. 23); mesosternum from dark brown to dark. Fore legs brown, middle and hind legs from light brown to yellowish. Length (mm) of foreleg segments: femora 2.7–3.1; tibia 2.4–2.7; tarsal segments 1.4–1.7, 1.5–1.9, 1.6–1.9, 1.3–1.6, 0.8–1.0. The ratio of length to the maximal width for fore wing—2.40 (Fig. 20), hind wing—1.47 (Fig. 21). Abdomen: terga 2–9 opaque with pair of elongated dark brown spots in middle part; lateral part of posterior margins darkened. Sterna brown, sterna 7–9 dark brown, opaque. Forceps brown, styliger plate dark brown. Middle part of posterior margin of styliger protuberant, wavy (Fig. 22). Penis lobes from dark brown up to black. External penis lobes wide with rounded apices; inner lobes straight, narrowed toward apex, with furcated top (Figs. 16–17). Ventral processes dark brown, pointed, reach ½ of length of external lobes (Figs. 17, 19). Cerci brown, with base darker.

Distribution. Parameletus chelifer has Holarctic distribution, occupying North America (McCafferty 1996), Europe (Söderström & Nilson 1986; Tshernova et al. 1986), Siberia, and Russian Far East (Tshernova et al. 1986; Kluge 1997; Tiunova 2007) (Fig. 8). Larvae of P. chelifer are found in small streams with cool water.