Parameletus minor Bengtsson 1909

Parameletus minor (Bengtsson 1909)

(Figs. 24–30)

Remipalpus minor Bengtsson 1908:242, nomen nudum. Potameis minor Bengtsson 1909:15.

Parameletus minor: Bengtsson: 1930:15.

Material examined. RUSSIA. Southern Yakutia: Ungra River Basin, Yuhktinka stream, mouth, light tributary of Yuhkta River, 28.VII – 1.VIII 2006, T. Tiunova, 1 male imago, 2 male and 1 female subimago. Khabarovskiy Kray: Priochot’e, Ul’ya River Basin, Khetana River, 7 km upper mouth, 13.VIII 1985, V Zherikhin, 1 male imago; same place, 23.VIII 1985, V Zherikhin, 1 male imago; Nikolaevskiy Region, Bolshaya Iski River, about 4 km upper mouth, 28.VI – 3.VII 2005, T Tiunova, 5 male imagines, 1 female imago (reared from larvae); Amur River Basin, Mutii River, near motor-car bridge, line Khabarovsk-Nikolaevsk-on-Amur Town, 30.VI 2005, T Tiunova, 9 male imago, 3 female imagines; same place, stream, right tributary of Mutii River, 30.VI 2005, T Tiunova, 1 male imago, 2 larvae; Tumnin River Basin, Stream Asecta, 100 m upper mouth, light tributary of Tumnin River, 29.VI 1997, T Tiunova, 1 male imago; Chor River Basin, stream near Srednechorskiy Village, 50 m upper mouth, right tributary Chor River, 13.VI 1995, T Tiunova, 4 male imagines.

Male imago. Dimensions: length (mm): body 8.0–10.6; fore wings 8.0–10.1; cerci 11.3–16.7. Total color of living imago dark brown. Head: upper portion of eyes light gray. Thorax: medioscutum and submedioscutum brown; sublateroscutum and posterior scutal protuberance dark brown (Fig. 30); mesosternum from dark brown to black. Fore legs brown, middle and hind legs light brown. Length (mm) of foreleg segments: femora 1.8–2.2; tibiae 1.5–2.0; tarsal segments 0.9–1.0, 1.0–1.3, 1.0–1.3, 0.8–1.0, 0.5–0.7. The relation of length to the maximal width makes for fore wing – 2.53, hind wing – 1.58. Abdomen: terga dark brown; terga 2–6 partial translucent with dark band on posterior margins; terga 7–9 opaque, tinged with whitish and with pair of elongated dark brown spots in middle part; lateral part in of posterior margins darkening. Sterna 2–6 brown, translucent; sterna 7–9 dark brown, opaque. Gonostyli pedestal, first and basal part second gonostylus segments and styliger dark brown; other gonostylus segments some lighter; posterior margin of styliger with a broad rectangular projection in middle part (Fig. 29). Penis dark brown, tinged darkish; external lobes at base thinner than at middle part, with apices pointed and curved inside; inner lobes wide and strong, with furcated top (Figs. 24–25). Ventral processes dark brown, short, pointed, reach ¼ of length of external lobes (Fig. 24– 25). Cerci brown.

Distribution. Parameletus minor is Palaearctic species, distributed from Fennoscandia to Far East of Russia (Fig. 8) (Saaristo & Savolainen 1980; Silfverberg 1984; Söderström & Nilson 1986; Tiunova 2007). Larvae of this species are found in small rivers or streams with cool water only.