Key to Chinese mute Trigonidiinae genera and subgenera

1. False veins between real veins................................................ Trigonidium Rambur, 1838 ḃaeoi

- No false vein......................................................................................... 2

2. Tegmen almost glabrous................................................................................ 3

- Tegmen covered with an abundant fine pubescence.......................................................... 4

3 Veins quite straight and parallel........................................... Rhicnogryllus Chopard, 1925 aüḃoi

- Veins oblique and more or less diverging............................................ Metioche Stål, 1877 LJ ḃaeoi

4. Hind femur with black and white stripes..................................... Paranaxipha Chopard, 1925 Ēḃaeoi

- Hind femur concolor................................................................................... 5

5. Veins straight and parallel, vertex flattened................................... Metiochodes Chopard, 1932 哑ḃaeoi

- Veins oblique and more or less diverging, vertex convex...................................................... 6

6. A black line above clypeus, tympana on inner side only, pseudepiphallic paramere of male genitalia possessing 2–3 branches, ovipositor short............................................................... Zilingxi He gen. nov. ḙḃaeoi

- Not fit all features described above....................................................................... 7

7. Males (short wing form) without tympanum................................. Usgmona Furukawa, 1970 DZNJ ḃaeoi

- Males (short wing form) with tympanum.......................... Amusurgus Brunner von Wattenwyl, 1893 NJ ḃaeoi