Stenus indubius, Sharp, 1889

Puthz, Volker, 2017, Neue und alte Arten der Stenus indubius-Gruppe aus China (Coleoptera, Staphylinidae) 354. Beitrag zur Kenntnis der Steninen, Linzer biologische Beiträge 49 (2), pp. 1353-1398 : 1355-1358

Key to the Chinese species of the Stenus indubius -group sensu lato (FB = forebody; S= sternum; Sp = spermatheca; T= tergum)

1 Abdominal segment 6 without a lateral suture or paratergites.............................................2

- Abdominal segment 6 with a lateral suture or with paratergites........................................11

2 Elytra with orange spots ......................................................................................................3

- Elytra uniformely blackish ..................................................................................................4

3 Elytral spot larger, extending to the posterior margin of elytra (fig 7, TANG & LI 2012). 3: E (figs 44-46, l. c.). ♀: Sp (fig. 50, l. c.). 4.0-4.7mm (FB 2.0-2.3mm). Guizhou (Gongtonggou) ..................................................................................... yinziweii TANG & LI

- Elytral spot smaller, not extending to the posterior margin of elytra (fig. 9, l.c.). E (figs 55-57, l. c.). ♀: Sp (fig. 61, l. c.). 4.3-5.0mm (FB 1.9-2.3mm). Guizhou (Baishagou)......... ......................................................................................................... zhaiyanbini TANG & LI

4 Segment 3 with narrow paratergites. 3: E (fig. 139). ♀: Sp (fig. 153). 3.8-5.0mm (FB 1.9-2.1mm). Shaanxi (Micang Shan)............................................... micangmontium nov.sp.

- Segment 3 without paratergites or a lateral separation line .................................................5

5 Smaller, FB <1.8mm ...........................................................................................................6

- Larger, FB>1.8mm.............................................................................................................7

6 Median portion of frons slightly elevated, not extending beyond the level of medial eye margins; elytra slightly uneven, punctation less dense, interstices about half as broad as diameter of punctures or larger. 3: E (figs. 7D-G, TANG & al 2012). ♀: Sp (figs 7J, K, l. c.). 2.6-3.3mm (FB 1.4-1.7mm). Anhui (Mt. Tianzhu) ................. paradecens TANG & al.

- Median portion of frons distinctly elevated, extending beyond the level of medial eye margins; elytra with irregular deep impressions, punctation denser, interstices less broad than half diameter of punctures. 3: Unknown. ♀: Sp (fig. 151). 3.1-3.6mm (F 1.6mm). Sichuan (Mt. Luoji).................................................................. luojimontis nov.sp.

7 Punctation of T7 denser, interstices less broad than diameter of punctures; elytra matt, punctation very dense, rugose, interstices less broad than diameter of punctures ...............8

- Punctation of T7 less dense, interstices as broad or broader than diameter of punctures; elytra as above OR shiny, punctation less dense, interstices often larger than diameter of punctures.........................................................................................................................9

8 3: E (fig. 133). ♀ Ô Sp (fig. 145). 3.8-4.2mm (FB 1.9mm). Shaanxi (Daba Shan) ............. ............................................................................................................... detestabilis nov.sp.

- 3: E (fig. 127). ♀: Sp (fig. 146). 3.8-4.2mm (FB 1.9mm). Shaanxi (Daba Shan) ................ ................................................................................................................. detestatus nov.sp.

9 Pronotum and elytra with deep impressions (figs 33, 43). 3: E (fig. 137). ♀: Sp (fig. 165). 4.0-4.7mm (FB 2.1mm). Sichuan (Emei Shan)......................... impressicollis nov.sp.

- Pronotum and elytra without deep impressions (figs 2, 4, TANG & al. 2012) ....................10

10 Elytra shorter (EL: EW 0.86-0.93). Habitus (fig. 4, l. c.). 3: E (figs 8D-E, l. c.). ♀: Sp. (figs 8J, K, l.c.). 4.3-4.8mm (FB 2.0-2.3mm). Anhui (Guniujiang Reserve)......................... .................................................................................................. guniujiangensis TANG & al.

- Elytra longer (EL: EW 0.95-0.96). Habitus (fig. 2, l. c.). 3: E (figs 6E-G, l. c.). ♀: Sp. (figs 6K, l. c.). 4.0-4.3mm (FB 2.0-2.2mm). Zhejiang (Qingliangfeng N. R.) ...................... ....................................................................................................... zhujianqingi TANG & al.

11 T3-6 with distinct paratergites...........................................................................................12

- T3-6 only with lateral suture .............................................................................................17

12 Elytra with an orange spot (e. g. figs 54-59) .....................................................................13

- Elytra black .......................................................................................................................16

13 Head broader (HW: EW>1.18), elytral spot larger, longer than one third of the elytral length, abdomen distinctly reticulated...............................................................................14

- Head less broad (HW: EW 1.05, elytral spot at most one third as long as the elytra, abdomen at most with faint reticulation. 3 E (fig. 110, PUTHZ 2011). ♀: Sp (fig. 167; fig. 112, l c.). 4.3-4.8mm (FB 2.1-2.3mm). Vietnam. China (Hainan (Limushan), Taiwan) ................................................................................................. vietnamensis PUTHZ

14 Elytra (fig. 31, PUTHZ, l.c.). 3: E (fig. 117, l. c.). ♀: Sp (fig. 113, l. c.). 4.0-5.4mm (FB 2.0-2.2mm). China (Taiwan) ................................................................. electristigma PUTHZ

- Elytra and E otherwise ......................................................................................................15

15 Elytra (fig. 33, PUTHZ, l.c.). 3: E (fig. 109, l. c.). ♀: Sp (about as in fig. 112, l. c.). 5.0- 6.0mm (FB 2.4-2.7mm). China (Taiwan) ...................................................... shibatai PUTHZ

- Elytra (fig. 34, PUTHZ, l.c.). 3: E (fig. 111, l. c.). ♀: Sp unknown. 4.6mm (FB 2.3mm). China (Taiwan) ...................................................................................... shibataiellus PUTHZ

16 Larger; FB 2.5mm. 3: E (fig. 140). ♀:Sp (fig. 154). 4.8-5.5mm. Shaanxi (Daba Shan).... ........................................................................................................... scabripunctus nov.sp.

- Smaller, FB 1.8mm. 3: E (fig. 125). ♀ unknown. 3.5-4.0mm. Shaanxi (Daba Shan)........ ................................................................................................................... dabacola nov.sp.

17 Elytra with  (often slightly) distinct reddish markings.. ..................................................18 (consider also S. xueshanus nov.sp. below)

- Elytra entirely blackish......................................................................................................24

18 Elytra very uneven, with a conspicuous central bump (figs 56, 59) ..................................19

- Elytra not or only less uneven ...........................................................................................21

19 Punctation of T7 finely and moderately dense, interstices much broader than diameter of punctures (fig. 79). 3: E (fig. 141). ♀: Sp (fig. 155). 3.8-4.2 (FB 1.8-2.1mm). Yunnan (Gaoligong Shan)................................................................... tumoripennis nov.sp.

- Punctation of T7 moderately coarse and much denser, interstices at most as broad as diameter of punctures (figs 82, 84)...................................................................................20

20 Elytra broader (EW: EL>1.15). Elytral punctation less dense. 3: E (fig. 135). ♀: Sp (figs. 156, 157). 3.5-4.0 (FB 1.7-2.0mm). Yunnan (Diancang Shan) .................................... .......................................................................................................... tumidulipennis nov.sp.

- Elytra less broad (EW: EL <1.15). Elytral punctation denser. 3: E (fig. 129). ♀: Sp (fig. 149). 3.7-4.2 (FB 1.8-2.0mm). Sichuan (Erlang Shan)................... erlanganus nov.sp.

21 Punctation of T7 less dense, interstices broader than diameter of punctures.....................22

- Punctation of T7 denser, interstices at most as broad as diameter of punctures. 3: E (figs 37-39, TANG & LI 2012). ♀: Sp?. 3.8mm (FB 1.8mm). Guangdong (Taiyangshan)............................................................................... taiyangshanus TANG & LI

22 Larger. Elytral spot distinct. 3: E (figs 5D-G, TANG & al. 2012). ♀: Sp (fig. 5K, l. c.)4.1-4.9mm. (FB 2.1-2.3mm). Guangxi (Anjiangping) .............. huapingensis TANG & al.

- Smaller. Elytra with smaller, slightly distinct markings....................................................23

23 Lateral portions of frons very densely punctate, interstices much less broad than half diameter of puncture. 3: Unknown. ♀: Sp (fig. 148). 3.4-4.2 (FB 1.8-1.9mm). Yunnan (Haba Shan)........................................................................................... habashanus nov.sp.

- Larger. Lateral portions of frons less densely punctate, interstices broader than half diameter of punctures. 3: E (fig. 138). ♀: Sp (fig. 152). 4.0-4.7 (FB 1.9-2.1mm). Sichuan (Mt. Luoji) ................................................................................... luojiensis nov.sp.

24 Punctation of T3 denser, interstices predominantly less broad than half diameter of punctures ...........................................................................................................................25

- Punctation of T3 less dense, interstices predominantly broader than half diameter of punctures ...........................................................................................................................29

25 Median portion of frons extending beyond the level of median eye margins ....................26

- Median portion of frons not extending the level of medial eye margins. 3: E (fig. 124). ♀ Unknown. 3.8-4.7 (FB 1.9-2.0mm). Yunnan (mountains S Jianshui) ............................... .......................................................................................................... aequabilifrons nov.sp.

26 Elytra with very deep longitudinal impressions, very uneven ...........................................27

- Elytra less uneven, without conspicuous long impressions ...............................................28

27 Abdominal punctation denser, interstices on T3-T7 distinctly less broad than half diameter of punctures; posterior margin of S7 of male without emargination. ♂: E (figs 11, 12, Tang & Zhao 2008. ♀: Sp (fig. 13, l.c.). 3.6-4.1mm (FB 1.8-2.2mm). Sichuan (Hailuoguo) ........................................................................... pectorifossatus TANG & ZHAO

- Abdominal punctation less dense, interstices on T3-T7 distinctly broader than half diameter of punctures; posterior margin of S7 of male with a slight median emargination. 3: E (fig. 130; figs 16, 17, TANG & ZHAO 2008). ♀: Sp (fig. 150; 18, l.c.). 3.4-4.0 (FB 1.8-2.2mm). Sichuan (Erlang Shan, Gongga Shan) ... erlangshanus TANG

28 Head broader (HW: EW>1.08). Elytra with a deep/strong humeral impression. 3: E (fig. 2a, TANG & PUTHZ 2009). ♀: Sp (fig. 2c, l. c.). 3.8-4.7 (FB 2.0-2.1mm). Shaanxi (Taibashan, Qinling Shan)....................................................................... hui TANG & PUTHZ

- Head less broad (HW: EW 1.05). 3: E (fig. 126). ♀: Sp (fig. 144). 4.0-4.5 (FB 1.9- 2.1mm). Shaanxi (Daba Shan).................................................................. dabaensis nov.sp.

29 Elytra conspicuously uneven, with a deep parasutural impression ....................................30

- Elytra less uneven, impressions missing or slight .............................................................34

30 Median portion of frons stronger elevated, extending beyond the level of median eye margins. 3: E (figs 6, 7, TANG & ZHAO 2008). ♀: Sp (fig. 8, l. c.). 3.0-3.6mm (FB 1.6- 1.9mm). Sichuan (Hailuoguo, Gongga Shan)............................... zhuxiaoyui TANG & ZHAO

- Median portion of frons less elevated, not extending beyond the level of median eye margins..............................................................................................................................31

31 Smaller, FB 1.6mm .........................................................................................................32

- Larger, FB 1.6mm...........................................................................................................33

32 Punctation of T7 denser, interstices at most as broad as half diameter of punctures. Elytra broader. 3: E (fig. 131). ♀: Sp (fig. 164). 2.8-3.4mm (FB 1.5-1.6mm). Sichuan (Niba Shan) ............................................................................................. nibamontis nov.sp.

- Punctation of T7 less dense, interstices often broader than diameter of punctures. Elytra less broad. 3: E (fig. 132). ♀: Sp (fig. 163). 3.0-3.6 (FB 1.6mm). Sichuan (Xiling Shan) .................................................................................................... xilingshanus nov.sp.

33 Punctation of lateral portions of frons denser, interstices distinctly less broad than half diameter of punctures. 3: E (figs 6, 7, TANG & ZHAO 2008). ♀: Sp (fig. 8, l. c.). 3.0- 3.6mm (FB 1.6-1.9mm). Sichuan (Hailuoguo, Gongga Shan).......... zhuxiaoyui TANG & ZHAO

- Punctation of lateral portions of frons less dense, interstices often broader than half diameter of punctures. 3: E (figs 26-28, TANG & LI 2012). ♀: Sp (fig. 32, l. c.). 3.0- 3.8mm (FB 1.6-1.9mm). Sichuan (Emei Shan) ................................... hewenjiae TANG & LI

34 Median portion extending beyond the level of medial eye margins ..................................35

- Median portion of frons not extending beyond the level of medial eye margin ................38

35 Punctation of T7 denser, interstices not or slightly broader than diameter of punctures ...36

- Punctation of T7 less dense, interstices distinctly broader than diameter of punctures .....37

36 3: Unknown. ♀: Sp (fig. 147). Larger. 4.0-4.5mm (FB 2.0mm). Yunnan (Jizu Shan) ........ ........................................................................................................................ hajeki nov.sp.

- 3: E (fig. 136). ♀: Sp (figs 160-162). Smaller. 3.7-4.3mm (FB 1.8-1.9mm). Yunnan (Zhemo Shan)...................................................................................... zhemoshanus nov.sp.

37 3: E (fig. 143). ♀: Sp (fig. 166). 3.9-4.2mm (FB 1.7-2.0mm). Yunnan (Zhongdian Co.)......................................................................................................... hongdianus nov.sp.

- 3: E (fig. 128). ♀: Unknown. 3.7-4.1mm (FB 1.8mm). Yunnan (Zhongdian Co.) .............. ............................................................................................................... insperabilis nov.sp.

38 Punctation of T7 denser, interstices not or slightly broader than punctures ......................39

- Punctation of T7 less dense, interstices distinctly broader than diameter of punctures .....40

39 3: E (figs 15-17, TANG & LI 2012). ♀: Sp (fig. 21, l. c.). 3.8-4.7mm (FB 1.9-2.2mm). Yunnan (Cangshan, Diancang Shan)................................................ cangshanus TANG & LI

- 3: E (fig. 134). ♀: Unknown. 3.3-3.8mm (FB 1.8mm). Yunnan (Zhemo Shan).................. ............................................................................................................... doryphorus nov.sp.

40 Head broader (HW: EW>1.10).........................................................................................41

- Head less broad (HW: EW 1.06).....................................................................................42 3: Unknown. ♀: Sp (fig. 147). Larger. 4.0-4.5mm (FB 2.0mm). Yunnan (Jizu Shan) ........ ........................................................................................................................ hajeki nov.sp.

41 Punctation of T3 denser, interstices less broad than diameter of punctures. 3: E (figs 12, 13, TANG & al. 2016). ♀: Sp (fig. 11,l. c.). 3.2-4.2mm (FB 1.7-1.9mm). Zhejiang (Tianmushan) ........................................................................... tonghanggangus TANG & al.

- Punctation of T3 less dense, interstices may become as broad as diameter of punctures. 3: E (fig. 142). ♀: Sp (figs 158,159). 3.5-4.1mm (FB 1.8-2.0mm). Yunnan (Xue Shan) .... ................................................................................................................. xueshanus nov.sp.

42 Punctation of abdomen denser, interstices on T7 at most as broad as punctures. 3 unknown. ♀: Sp (fig. y). Larger. 4.0-4.5mm (FB 2.0mm). Yunnan (Jizu Shan; E Weishan) ......................................................................................................... hajeki nov.sp.

- Punctation of abdomen less dense, interstices on T7 twice as broad as punctures. 3: E (fig. 138). ♀: Sp (fig. 152). 4.0-4.7 (FB 1.9-2.1mm). Sichuan (Mt. Luoji)........................... .................................................................................................................. luojiensis nov.sp.