Isoperla eximia ZAPEKINA-DULKEIT, 1975

Zwick, P & Surenkhorloo, P, 2005, The Mongolian Species Of Isoperlinae (Plecoptera: Perlodidae), Acta Zoologica Academiae Scientiarum Hungaricae 51 (3), pp. 253-276 : 263-264

Isoperla eximia ZAPEKINA-DULKEIT, 1975

( Figs 6b, c )

Isoperla eximia ZAPEKINA-DULKEIT, 1975: 211 , figs 14–19.

Material studied. MONGOLIA, Selenge aimak, Mandal sum, Khonin nuga: Bar-Chuluut River (48°58’N, 106°59’E), tributary of Eroo River , 1 f, 21.VIII.2001 ; 13 mm, 1 f, 04.VIII.2003; [49°02’N, 106°58’E] 2 mm, 05/ 06.VIII.2003; Uram River, tributary of Khongi River , 1 m, 22.VII.2001 ; Ataa River, tributary of Sharlan River , 9 mm, 1 f, 30.VII.2003 (all leg. P. SURENKHORLOO).

A sibling of I. altaica with which it occurs sympatrically. Our specimens were identified by comparison with an illustration of the genitalia of the male holotype (from Bargusinskyi Reserve, Birikan River, 4.08.1972, leg. V. A. BELYAEVA; in ZIAS) kindly provided by Dr V. TESLENKO .

I. eximia is macropterous. It differs from I. altaica by the central field of the pterothoracic scuta distinctly paler than the lateral parts. The head has a small pale mark on the occiput and a dark shade in front of the pale frontoclypeal mark, but lacks tranverse marks connecting the eyes.

Size. Fore wing length, mm 10.0– 10.2 mm, ff slightly larger.

The penial sclerite is of the same general form as in I. altaica , but the base is not strikingly wider than the apex and not distinctly crested.

Egg. Similar to eggs of Mongolian I. altaica .

Figures

Fig. 6. Isoperla altaica ŠÁMAL (a) and I. eximia ZAPEKINA-DULKEIT (b, c). Penis sclerites (a, b; to same scale) and fore body (c; not to scale)