Key to Chinese species of subgenus Hysterobolus Viereck

1 Vein M+CU of hind wing distinctly shorter than vein 1-M; penultimate flagellomere quadrate, about as long as wide (Fig. 6C); length of malar space 3.0 × to basal width of mandible; first metasomal tergite about 2.1 × longer than its apical width (Fig. 6F)......................................................................... B. (H.) laculaticornis sp. nov.

- Vein M+CU of hind wing about subequal to vein 1-M; penultimate flagellomere distinctly longer than wide (Fig. 8D); length of malar space at most 2.8 × basal width of mandible; first tergite usually 1.5–1.8 × longer than wide apically (Figs 2H, 4H, 8E, 10J, 12F, 16F, 18E), except in B. variegatus (Fig.14E)........................................................ 2

2 Length of vein r of fore wing almost equal to width of pterostigma; antennomeres 20; length of hind basitarsus 10.0 × its width; head yellow....................................................................... B. (H.) flaviceps sp. nov.

- Length of vein r of fore wing 1.1–1.5 × width of pterostigma; antennomeres less than 20; length of hind basitarsus 7.1–8.8 × its width; colour of head variable........................................................................... 3

3 Malar suture present................................................................................... 4

- Malar suture absent.................................................................................... 5

4 Vein 2-CU1 of fore wing 1.2 × longer than vein 1-CU1 (Fig. 18F); face largely smooth; precoxal sulcus narrow, striae very short (Fig. 18G)..................................................................... B. (H.) yunnanensis sp. nov.

- vein 2-CU1 of fore wing 2.2 × longer than vein 1-CU1(Fig. 20I); face transversely rugose; precoxal sulcus wide, striae long (Fig. 20F)............................................................ B. (H.) chabarovi Belokobylskij, 1995

5 Hind tibia yellow or reddish-brown....................................................................... 6

- Hind tibia dark brown or blackish-brown.................................................................. 8

6 First metasomal tergite 1.5 × longer than its apical width (Fig. 8E); length of pterostigma 3.5 × its maximum width; length of terminal flagellomere 3.0 × its width; body generally black............................. B. (H.) longiapicalis sp. nov.

- First tergite 1.7–2.1 × longer than its apical width; length of pterostigma 5.0 × its maximum width; length of terminal flagellomere 2.8 × its width; body generally reddish-brown............................................................... 7

7 Length of first flagellomere 1.7 × second flagellomere; scutellum smooth medially; antennomeres 18; occiput slightly concave (Fig. 14A); hind tibia reddish-brown; 2–3 apical flagellomeres dark brown; first metasomal tergite about 2.1 × longer than its apical width (Fig. 14E)............................................................ B. (H.) variegatus sp. nov.

- Length of first flagellomere 1.4 × second flagellomere; scutellum rugose medially; antennomeres 19; occiput distinctly concave (Fig. 10A); hind tibia yellow; 5–6 apical flagellomeres dark brown; first tergite 1.7–1.8 × longer than its apical width (Fig. 10J)........................................................................ B. (H.) melanoapicalis sp. nov.

8 Fore claw of ♀ with blackish bristles (Fig. 12I); face weakly rugose (Fig. 12B); striae of precoxal sulcus medium-sized; vein 2-1A of hind wing absent (Fig. 12H)...................................................... B. (H.) niger sp. nov.

- Fore claw of ♀ with brownish bristles (Figs 2J, 16I); face coarsely rugose (Figs 2B, 16B); striae of precoxal sulcus long; vein 2-1A of hind wing present (Figs 2M, 18F).................................................................. 9

9 Terminal flagellomere 2.7–2.9 × longer than wide; first discal cell of fore wing acute (Fig. 16H); setose part of ovipositor sheath slightly longer, 0.21 × length of fore wing; mesoscutum largely dark brown to black; hind femur dark brown to blackish-brown............................................................................... B. (H.) xui sp. nov.

- Terminal flagellomere about 2.2 × longer than wide; first discal cell of fore wing truncate (Fig. 2L); setose part of ovipositor sheath slightly shorter, 0.18 × length of fore wing; mesoscutum yellowish-brown; hind femur yellow............................................................................................. B. (H.) baishanzuensis sp. nov.