Stenus,

Tang, Liang, Puthz, Volker & Yue, Yan-Li, 2016, A study on the genus Stenus Latreille from Tianmushan Mountain Chain of East China (Coleoptera, Staphylinidae), Zootaxa 4171 (1), pp. 139-152: 149-150

Key to Stenus  Edit species of Tianmushan Mountain Range

1 Legs with tarsomeres IV distinctly simple.................................................................. 2

- Legs with tarsomeres IV distinctly bilobed................................................................. 10

2 Abdominal segments without paratergites.................................................................. 3

- Abdominal segments with distinct paratergites............................................................... 4

3 Forebody with setae suberect, elytra shorter than wide.............................................. S. hirtiventris  Edit

- Forebody with setae recumbent; elytra as long as wide............................................. S. pilosiventris  Edit

4 Elytra each with an orange spot.................................................................. S. tenuipes  Edit

- Elytra entirely black................................................................................... 5

5 Abdominal tergites of segments III –V without longitudinal basal carina........................................... 6

- Abdominal tergites of segments III –V with longitudinal basal carinae............................................ 7

6 Basal half of femora distinctly lighter than apical half (applicable only on the population from Tianmushan Area), male sternite VII with posteromedian portion flattened, internal sac of aedeagus broad................................... S. eurous  Edit

- Basal half of femora slightly lighter than apical half, male sternite VII with posteromedian portion distinctly impressed, inter- nal sac of aedeagus narrow.................................................................... S. pubiformis  Edit

7 Abdominal tergites of segments III –V with three longitudinal basal carinae........................................ 8

- Abdominal tergites of segments III –V with four longitudinal basal carinae.................... S. melanarius melanarius  Edit

8 Sternite IX acute apicolaterally.................................................................. S. japonicus  Edit

- Sternite IX serrate apicolaterally........................................................................ …9

9 Paratergites less broad, directed ventrad............................................................. S. distans  Edit

- Paratergites broader, directed horizontally................................................. S. lewisius pseudoater  Edit

10 Abdomen with long and suberect setae.................................................................... 11

- Abdomen with short and recumbent setae................................................................. 12

11 Apterous, elytra without orange mark................................................................ S. cirrus  Edit

- Macropterous, elytra each with longitudinal orange mark.......................................... S. guangxiensis  Edit

12 Abdominal segments III –VI with paratergites.............................................................. 13

- Abdominal segments III –VI without paratergites........................................................... 15

13 Smaller species, BL: 3.5–4.4 mm, elytra without orange mark........................................ S. rugipennis  Edit

- Larger species, BL> 5 mm, elytra each with orange mark.................................................... 14

14 Head nearly as wide as elytra, elytra distinctly shorter than wide......................................... S. gestroi  Edit

- Head distinctly narrower than elytra, elytra nearly as long as wide...................................... S. maculifer  Edit

15 Tergite X with posterior margin bicuspid, punctation of entire body extremely dense................ S. rorellus cursorius  Edit

- Tergite X with posterior margin round, punctation of entire body sparser......................................... 16

16 Macropterous, large species............................................................................ 17

- Apterous or Brachypterous, usually small species........................................................... 20

17 Tergite 8 with a posteromedian patch of dense shiny setae, PL/PW<1.2.......................................... 18

- Tergite 8 without a posteromedian patch of dense shiny setae, PL/PW>1.3.......................... S. plagiocephalus  Edit

18 Stout species, legs bicolor................................................................... S. cicindeloides  Edit

- Slender species, legs entirely yellow...................................................................... 19

19 Abdominal tergite VI smooth................................................................. S. bispinoides  Edit

- Abdominal tergite VI reticulated................................................................... S. currax  Edit

20 Pronotum distinctly lighter than head, forebody with interstices reticulated........................... S. pseudomicuba  Edit

- Pronotum as dark as head, forebody with interstices smooth................................................... 21

21 Larger species, FB: 1.7–2.4 mm, sternite IX with apicolateral projections very long................................ 22

- Smaller species, FB: 1.4–1.6 mm, sternite IX with apicolateral projections less long.......................... S. decens  Edit

22 Larger species, FB: 1.7–1.9 mm, punctation of pronotum and elytra very confluent..................... S. tianmushanus  Edit

- Smaller species, FB: 2.2–2.4 mm, punctation of pronotum and elytra less confluent.................. S. tonghanggangus  Edit