Isoperlinae

Zwick, P & Surenkhorloo, P, 2005, The Mongolian Species Of Isoperlinae (Plecoptera: Perlodidae), Acta Zoologica Academiae Scientiarum Hungaricae 51 (3), pp. 253-276 : 254-255

Key to adult Mongolian Isoperlinae

1 Femora short, bristly. Each cercus segment with an apical whirl of long setae. No ventral lobe on male sternite 8. Female subgenital plate short, shallowly bilobed. Egg with 6 longitudinal ribs ( Fig. 8 ) Isoperla potanini

1’ Femora slender, not bristly. Cercus segments caudally with a single ventral seta very much longer than the others. Genital characters variable. Egg not ribbed 2

2 Head pale with a compact isolated central dark mark 3

2’ The dark mark in the middle of head includes some variably extended pale area; the dark pattern reaching the eyes, the occiput, or the front edge of head 4

3 Dark mark on head posteriorly excised. Male: vesicle dark, narrow, a little widened caudally, distally truncate. Distal edge of male subgenital plate truncate, wider than front of segment 9, penis with single large symmetrical sclerite. Female subgenital plate distinctly brace-like, strongly pigmented ( Figs 1 , 2 ) I. lunigera

3’ Mark on head squarish. Male: vesicle on sternite 9 parallel-sided. Subgenital plate caudally rounded, of normal width; penis without major sclerites. Female subgenital plate little extended and pigmented I. maculata

4 Males 5

4’ Females 11

5 Abdominal segments 3 and 4 with a pointed lateral process Kaszabia spinulosa

5’ Abdominal segments simple, without lateral process 6

6 Sternite 8 with a distinct racket-shaped ventral lobe 7

Figures

Fig. 8. Isoperla potanini (KLAPÁLEK): a = head and prothorax, b = hind leg, c, d = middle portion of cercus, e = male abdominal tip, ventral view, f = the same, dorsal view; g = cleared penis membrane, details of armatures all at the same magnification but not to scale, h = female abdominal tip, ventral

Fig. 1. Isoperla lunigera (KLAPÁLEK). a = head and pronotum, b = female sternite 8, c = dissected sternites 8 and 9 in dorsal view, showing genital pouch, receptacle, andaccessory glands; d = detail of genital pouch and receptacle, e = egg, f = detail of collar indicating chorion thickness and inner parts

Fig. 2. Isoperla lunigera (KLAPÁLEK). a–c = penis sclerite in lateral, oblique lateral, and caudal views, respectively (from ZWICK et al. 1971)