Key to species of Ontholestes fauna of China

1. Body large, longer than 15 mm, sometimes nearly reaching 20 mm; temple almost as long as diameter of eye viewed from above............................................................................ O. tessellatus (Geoffroy)

- Body small, less than 15 mm long, temple shorter than diameter of eye viewed from above........................... 2

2. Vertex with small smooth longitudinal space basally.......................................................... 3

- Vertex without small smooth longitudinal space basally....................................................... 4

3. Clypeus light yellow and smooth, without longitudinal grooves.............................. O. proximus Kirshenblat

- Clypeus pitchy black with fine but distinct longitudinal grooves............................... O. orientalis Bernhauer

4. Deflexed sides of elytra yellowish red.................................................. O. simulator Kirshenblat

- Deflexed sides of elytra black............................................................................ 5

5. Maxillary palps brown, distal half of their last segment black.................................... O. oculatus (Sharp)

- Maxillary palps entirely black............................................................................ 6

6. Antennae with 4–5th segments long, 4th at least twice as long as wide, 5th distinctly longer than wide.................... 7

- Antennae with 4–5th segments short, 4th at most 1.5 times as long as wide, 5th only slightly longer than wide.............. 8

7. Posterior margin of abdominal sternite VIII with rounded emargination medially; aedeagus with apex of paramere triangular....................................................................... O. xinqiaoensis Yang & Zhou sp. nov.

- Posterior margin of abdominal sternite VIII with triangular emargination medially, aedeagus with apex of paramere rounded................................................................................... O. tenuicornis (Kraatz)

8. Head wider than the pronoum............................................................................ 9

- Head narrower than pronodum.......................................................................... 10

9. Temples very short, eyes large and occupying nearly entire lateral length of head................ O. aurosparsus (Fauvel)

- Temples only slightly shorter than diameter of eyes viewed from above............................ O. murinus (Linné)

10. Temples extremely short, eyes very large and occupying almost entire lateral length of head................................................................................................... O. napoensis Yang & Zhou sp. nov.

- Temples almost half as long as diameter of eye viewed from above............................ O. callistus (Hochhuth)