Parameletus minor ( Bengtsson 1909 )

Tiunova, Tatiana M., 2008, Two new species of Parameletus Bengtsson, 1908 (Ephemeroptera: Siphlonuridae), and notes on other species from the Far East of Russia, Zootaxa 1725, pp. 17-26 : 23-25

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.

Figures

FIGURE 8. Study area. The thick line indicates the border between administration regions. 1 – Primorskiy Kray, 2 – Khabarovskiy Kray, 3 – Sakhalinskaya Oblast’, 4 – Magadanskaya Oblast’, 5 – Kamchatskaya Oblast’, 6 – Chukotka, 7 – Evreiskaya Autonomous Oblast’, 8 – Amurskaya Oblast’, 9 – Chitinskaya Oblast’, 10 – Republic Sakha Yakutia.

FIGURES 24 – 30. Parameletus minor: 24. Penis, ventral. 25. Penis, dorsal. 26. Penis, lateral. 27. Fore wing. 28. Hind wing. 29. Styliger and gonostyli. 30. Mesonotum, dorsal. Scale (mm): 24 – 26 = 0.02; 27 – 28 = 0.1; 29 = 0.05; 30 = 0.5.