Metrodorinae Bolívar, 1887

Lu, Xiang-Yi & Deng, Wei-An, 2021, New genus and new species of the subfamilyMetrodorinae from China (Orthoptera Tetrigidae), Zootaxa 4964 (2), pp. 345-362 : 346

Key to the Chinese genera of Metrodorinae Bolívar, 1887

Modified from Deng (2016), based on generic diagnosis of Pseudoxistrella Liang, 1991 , Pseudoxistrella spp. share the following characteristics: antennae filiform, fascial carina of the frontal costa diverge a little or runs parallel, posterior angles of lateral lobes turned downwards, apex of posterior angles rounded. The genus Pseudoxistrella should be transferred to subfamily Tetriginae . Therefore, this genus is omitted from the identification key. Thus, the subfamily Metrodorinae currently includes 16 genera (including the new genus Concavetettix Deng , gen. nov.) in China.

1. Fastigium of the vertex distinctly projecting before anterior margin of compound eyes............................... 2

- Fastigium of the vertex not or slightly projecting before anterior margin of compound eyes........................... 4

2. Fastigium of the vertex calyptriform protruding before anterior margin of compound eyes......... Calyptraeus Wang, 2001

- Fastigium of the vertex angular projecting or square projecting................................................. 3

3. Fastigium of the vertex angular projecting; antennal grooves inserted between inferior margin of compound eyes...................................................................................... Rhopalotettix Hancock, 1910

- Fastigium of the vertex square projecting; antennal grooves inserted lowest third of compound eye height...................................................................................... Miriatroides Zheng & Jiang, 2002a

4. With a distinct obtuse projecting under each lateral carina of prozona; pronotum platy, in dorsal view, dorsum of pronotum with irregular concavities........................................................... Concavetettix Deng , gen. nov.

- Without obtuse projecting under each lateral carina of prozona; pronotum tectiform................................. 5

5. Vertex narrow, still narrower towards front, eyes draw to each other in front and elevated....... Systolederus Bolívar, 1887

- Vertex not the same as above............................................................................ 6

6. Posterior margins of each lateral lobes of pronotum only with ventral sinus..................................................................................................... Macromotettixoides Zheng, Wei & Jiang, 2005

- Posterior margins of each lateral lobe of pronotum with ventral sinus and tegminal (upper) sinus...................... 7

7. Humeral apex ridge and lower margin of pronotum connected in the middle or behind middle of lower margin of pronotum.. ................................................................................................... 8

- Humeral apex ridge and lower margin of pronotum connected before middle of lower margin of pronotum.............. 9

8. Tegmina and hind wings present................................................. Macromotettix Günther, 1939

- Tegmina absent and with vestigial hind wings........................... Pseudomacromotettix Zheng, Li & Lin, 2012

9. Tegmina present and hind wings absent............................................. Paramphinotus Zheng, 2004

- Tegmina and hind wings present........................................................................ 10

10. Ventral margins of fore femora and middle femora with two big teeth..................... Orthotettixoides Zheng, 1998

- Ventral margins of fore femora and middle femora without big tooth............................................ 11

11. Head and eyes not exserted above pronotal surface.......................................................... 12

- Head and eyes distinctly exserted above pronotal surface..................................................... 13

12. Anterior part of pronotum strongly widened, arched and uplifted............................. Hyboella Hancock, 1915

- Anterior part of pronotum normal and strongly widened................................. Bolivaritettix Günther, 1939

13. Antennal grooves inserted far below inferior margin of compound eyes......................................... 14

- Antennal grooves inserted inserted lowest third of compound eye height or between inferior margin of compound eyes... 15

14. The vertex horn is distinctly raised above the dorsal margin of eyes and the vertex is deeply depressed between eyes in frontal view; pronotum between the shoulders is not elevated to an obtuse gibbosity...................... Xistra Bolívar, 1887

- In frontal view, the vertex horn slightly raised above the dorsal margin of eyes or not and the vertex slightly depressed or not depressed between eyes; pronotum between the shoulders generally strongly elevated to an obtuse gibbosity............................................................................................... Xistrella Bolívar, 1909

15. Antennal grooves inserted inserted lowest third of compound eye height; median carina of pronotum with a series projections......................................................................... Cotysoides Zheng & Jiang, 2000

- Antennal grooves inserted inserted between inferior margin of compound eyes; median carina of pronotum generally straight or undulated..................................................................... Mazarredia Bolívar, 1887