Key to the species Apterolarnaca

1 Internal spines of male hind femora obviously larger than external ones (Bian & Shi, 2015: Fig. 5; Bian et al., 2016: Figs. 1D, 2E; Ingrisch, 2018: Fig. 39A; Bian et al., 2021b: Fig. 1H)......................... Apterolarnaca (Apterolarnaca) ... 2

- Internal spines of male hind femora slightly larger than external ones (Figs. 5E, 6E, 9J–K)................................................................................................... Apterolarnaca (Bianigryllacris) ... 8

2 Middle tibiae without apical spine on dorsal surface.......................................................... 3

- Middle tibiae with apical spine on dorsal surface............................................................ 7

3 Face black and occiput black (Bian et al., 2016: Figs. 1A), posterior margin of male subgenital plate with 1 U shaped concavity..................................................................... A. (A.) nigrifrontis Bian & Shi, 2016

- Face yellowish brown with black marks (Gorochov, 2004: Fig. 99; Bian et al., 2016: 2 A; Bian et al., 2021b: Fig. 1A)...... 4

4 Face with large black mark in middle area (Bian et al., 2021b: Fig. 1A), posterior concavity of male subgenital plate with narrower at base (Bian et al., 2021b: Fig. 1F, G)................................ A. (A.) huanglianensis Bian & Lu, 2021

- Face with small black spots (Gorochov, 2004: Fig. 99; Bian et al., 2016: 2 A)...................................... 5

5 Face with 3 black spots (Gorochov, 2004: Fig. 99), male subgenital plate with lateral lobes slightly bifurcate apically (Gorochov, 2004: Figs. 101–102); posterior margin of female subgenital plate slightly projected in the middle (Gorochov, 2004: Fig. 104).......................................................................... A. (A.) ulla Gorochov, 2004

- Face with 4 black spots (Bian et al., 2016: 2 A), male subgenital plate with lateral lobes obviously bifurcate apically (Bian et al., 2016: 2 F)........................................................ A. (A.) quadrimaculata Bian & Shi, 2016

6 Dorsal surface of body with 1 longitudinal black band along the midline (Ingrisch, 2018: 39 B); posterior margin of male ninth abdominal tergite with 1 pair of spines (Ingrisch, 2018: 39 E); posterior concavity of male subgenital plate not projected at middle area; female subgenital plate longer than broad (Gorochov, 2004: Fig. 98); basal area of ovipositor with 1 pair of digitate lobes, projecting backward (Gorochov, 2004: Fig. 98).................................. A. (A.) apta Gorochov, 2004

- Body yellowish brown with black marks (Figs. 1–4); lateral margins of male ninth abdominal tergite terminating into a pair of narrowly lobate processes, its apices prolonged into a small spine at internal margin (Fig. 2F); posterior concavity of male subgenital plate obviously projected at the basal area in the middle (Fig. 2G); female subgenital plate wider than long (Figs. 1F, 3G)................................................................... A. (A.) truncatoloba (Li & Liu, 2015)

7 Frons with broad transverse sulcus (Bian et al., 2014: Fig. 5A, C).................. A. (B.) parvospinus (Liu & Yin, 2002)

- Frons smooth, without broad transverse sulcus.............................................................. 8

8 Body almost unicolor without black band on dorsal surface (Fig. 12)...................... A. (B.) xinganensis sp. nov.

- Dorsal surface of body with black band along the midline..................................................... 9

9 Apices of fore and middle femora without black stripes...................................................... 10

- Apices of fore and middle femora with black ring-like stripes.................................................. 12

10 Ovipositor with well-developed digitate lateral lobes at base of lower sheaths..................................... 11

- Ovipositor without digitate lateral lobes at base of lower sheaths (Bian et al., 2014: Fig. 2K).................................................................................................... A. (B.) digitatus (Liu & Bi, 2008)

11 Posterior concavity of male subgenital plate with 1 bilobed process at basal area (Bian et al., 2014: Fig. 1G), posterior margin of female subgenital plate rounded (Bian et al., 2014: Fig. 1L)...................... A. (B.) bilobus (Guo & Shi, 2012)

- Posterior concavity of male subgenital plate not projected in the middle (Li et al., 2015: Fig. 28), female subgenital plate truncate (Li et al., 2015: Fig. 29)........................................... A. (B.) transversa (Liu, Bi & Zhang, 2010)

12 The black band of dorsal surface of body only reaching the posterior margin of metanotum (Guo & Shi, 2012: Fig. 15; Li et al., 2015: Fig. 7), posterior margin of female subgenital plate nearly straight, emarginate (Li et al., 2015: Fig. 9).................................................................................. .. A. (B.) parvospinus (Liu & Yin, 2002)

- The black band of dorsal surface of body reaching the apex of abdomen......................................... 13

13 Face with 1 longitudinal black stripe in the middle (Figs. 5A, 6A, 7A)........................................... 14

- Face without black stripe in middle (Bian et al., 2015: Fig. 4A, H); posterior margin of female subgenital plate nearly truncate (Bian et al., 2015: Fig. 4L)............................................. A. (B.) nigrigeniculatus (Liu & Yin, 2002)

14 Face with 1 longitudinal black stripe in the middle, which connecting the transverse stripe at fastigium verticis, fronto-clypeal suture with 1 pair of black spots (Figs. 6A, 7A); posterior margin of female subgenital plate almost straight (Fig. 7G)................................................................................... A. (B.) tenuispinacia sp. nov.

- The longitudinal black stripe of face not connecting with the transverse stripe at fastigium verticis (Bian et al., 2014: Figs. 3A, H, 6A, H), fronto-clypeal suture without black spots......................................................... 15

15 Face with 1 longitudinal black stripe in middle (Bian et al., 2014: Fig. 6A, H); pronotum and abdominal tergites with 1 black stripe in middle; the apical processes of lateral lobes of male subgenital plate digitate, subapical area of the processes obviously contracted (Bian et al., 2014: Fig. 6F, G)........................................ A. (B.) trilobus (Bian & Shi, 2014)

- Frons with 1 longitudinal brown stripe in middle (Fig. 5A); pronotum and abdominal tergites with 1 black brown stripe in middle; the apical processes of lateral lobes of male subgenital plate stout, subapical area of the processes not contracted (Bian et al., 2014: Fig. 3D, F); female subgenital plate length equal to wide, posterior margin slightly projected in the middle (Fig. 5G)........................................................................ .. A. (B.) fallax (Liu & Bi, 2008)