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 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

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

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

- 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

- 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

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

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

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

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

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

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

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

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

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

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

- 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

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

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

- 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

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

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

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

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

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

- 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

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

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