Stenus Puthz 2013
Creators: name: Puthz, V.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Stenus

description: Key to the groups of the Oriental species of the genus Stenus
1 Abdominal segments 4-6 margined (margin can be thread-like).........................................2
- Abdominal segments 4-6 immargined.................................................................................3
2 Tarsi simple (segment 4 not bilobed) .......................................................................... key A
- Tarsi bilobed (segment 4 bilobed)............................................................................... key B
3 Tarsi simple....................................................................................... S. perplexus -group pp.
- Tarsi bilobed ............................................................................................................... key C
A. Key to the Oriental species of the genus Stenus LATREILLE with distinct paratergites and simple (not bilobed) tarsi exclusively brachypterous/apterous montane Chinese species
1 Base of abdominal tergites without short carinae................................................................2
- Base of abdominal tergites with short carinae...................................................................45
2 Sternum 9 with an acute and prominent apicolateral tooth (figs 18-20)..............................3
- Sternum 9 serrate apicolaterally (this character may be difficult to find), posterior margin of the sternite finely serrate (figs 21-26). Median lobe with (S. pusillus -group) or without expulsion claps or expulsion hooks (figs 85, 86) (S. seminiger -group, S. comma-group)...................................................................................................................33
3 Abdomen with conspicuously long and erect setae (figs 6, 7).: Aedeagus (fig. 14, PUTHZ 2009c). China (Taiwan). (S. cirrus- group p.p.)....................... S. cirrivarians PUTHZ
- Abdomen not with conspicuously long and erect setae.......................................................4
4 Smaller species: FB <2.6 mm. Posterior margin of the sternite ± smooth. Median lobe with expulsion clasp or expulsion hooks.............................................................................5 - Larger species (FB>2.5mm). Posterior margin of the sternite distinctly or very finely serrate (figs 22, 23, 25, 26). Median lobe without expulsion clasps or expulsion hooks (S. seminiger -group p.p.....................................................................................................26
5 Small metallic species.: Apical portion of median lobe setaceous.: Spermatheca sclerotized (S. viridescens -group).......................................................................................6
- Blackish species of various length.: Apical portion of median lobe not setaceous.: Spermatheca sclerotized or not sclerotized....................................................................7
6 Larger: 3.0-3.5mm.: Aedeagus (fig. 70). N India ....................... S. viridescens CAMERON
- Smaller: 2.3-2.8mm.: Aedeagus (fig. 71).: Spermatheca (fig. 77). (N India) ............... ....................................................................................................... S. almorensis CAMERON
7 Brachypterous species, FB 1.6mm.: Spermatheca sclerotized........................................ .......................................................................... S. alpicola -group and S. brahmanus -group S. dodabettamontis PUTHZ.: Unknown.: Valvifer (Abb. 27). S India; S. morosus CAMERON.: Aedeagus resembling fig. 72). India, Pakistan; sikh PUTHZ.: Aedeagus (figs 4, 5, PUTHZ 1985b). India, Pakistan; S. brahmanus -group (see below)
- Macropterous species ..........................................................................................................8
8 Species with long conspicuous recumbent pubescence, especially distinct on abdomen.: Aedeagus without a long flagellum or a long median tube.: Spermatheca not sclerotized. (mendicus -group =) ................................................................ S. incanus -group S. eurous PUTHZ (fig. 18, l. c.).: Aedeagus (figs 33-35, l. c.). China, Vietnam, Laos; S. fukiensis L. BENICK.: Aedeagus (fig. 31, l. c.). China; S. insulindicola PUTHZ.: Aedeagus (fig. 82, l. c.). Indonesia: Sumatra; S. insulindicus ROUGEMONT.: Aedeagus (fig. 83, l. c.). Indonesia: Bali; S. koreanus PUTHZ.: Aedeagus (fig. 19, l. c). Korea; S. lanicutis PUTHZ.: Aedeagus (figs. 22, 32, 36, l.c.). China; S. lanosivestis PUTHZ.: Aedoeagus (fig. 7, PUTHZ 2012c). Myanmar; S. lanosus PUTHZ.: Aedeagus (figs. 78-81, l. c.). China; S. puberulus SHARP.: Aedeagus (figs 23-28, PUTHZ 2012a). Japan; S. pubiformis PUTHZ.: Aedeagus (figs. 20, 29, 30, l.c.). China, Korea, Russia.
- Species without conspicuous pubescence.: Spermatheca sclerotized..............................9
9: Aedeagus with a long flagellum or a long median tube.: Spermathecal duct slender (fig. 83).................................................................................................................10
-: Aedoeagus without a long flagellum (figs 72, 82).: Spermatheca sclerotized, spermathecal duct stout. 3.8-4.4mm (FB 2.0-2.4mm). Pakistan, Indien, Nepal, Bhutan ....... .......................................................................................................... S. musicola CAMERON
10 Smaller species: FB <1.8mm.: Median lobe simple posteriorly S. javanus -group........11
- Larger species: FB>1.9mm.: Median lobe with the internal tube/flagellum projecting posteriorly (figs 79-81) S. flagellifer -group.....................................................21
11 Larger: FB 1.6mm...........................................................................................................12
- Smaller: FB <1.6mm.........................................................................................................13
12 Punctation of elytra and pronotum less coarse, mostly distinctly delimited. Abdominal punctation denser, interstices on posterior portion of tergites at most as large as punctures.: Apical portion of median lobe acute, much longer than the parameres (fig. 78). 3.3-4.2mm (FB 1.8mm). Myanmar .......................................... S. collium FAUVEL
- Punctation of elytra and pronotum coarser, slightly rugose. Abdomen less densely punctate, interstices on posterior portion of tergites larger than punctures.: Aedeagus (fig. 2, PUTHZ 1969), median lobe much shorter than parameres. 3.3-4.2mm (FB 1.8mm). Myanmar, Thailand, Laos ........................................................... S. comes FAUVEL
13 Elytra with a reddish yellow spot......................................................................................14
- Elytra blackish. Several very similar species which should be identified by their sexual characters..........................................................................................................................15 14 Elytral spots larger, about as long as antennal segments 3-5.: Aedeagus (fig. 1, ROUGEMONT 1987), apical portion of median lobe about half as long as in S. pederseni, with narrow ventral carinae. 2.7-3.3mm (FB 1.5mm). Thailand ........................................... ................................................................................................... S. kamhaengi ROUGEMONT
- Elytral spots smaller, about as long as antennal segment 3. Head broader (HW: EW 1.00).: Aedeagus (fig. 73).: Spermatheca (fig. 83). 2.7-3.3mm (FB 1.5-1.6mm). Laos ....................................................................................................... S. pederseni nov.sp.
15 Smaller: 2.0-2.7mm (FB 1.3-1.4mm).: Aedeagus (figs 12, 15, PUTHZ 2012a), apical portion.: Spermatheca (fig. 16, l. c.). China (Taiwan), Japan (Ryukyu Islands), Malaysia (Sabah), Laos ........................................................................ S. riukiuensis PUTHZ
- Larger: 2.4-3.4mm. Aedeagus different............................................................................16
16 Head broader (HW: EW  1.0).........................................................................................17
- Head less broad (HW: EW>0.95).....................................................................................20
17 Punctation of elytra coarser, diameter of punctures larger than diameter of antennal segment 1.: Median lobe closely resembling that of S. riukiuensis, but the apical portion shorter, parameres about as in S. sannio (PUTHZ 2012a, fig. 15). 2.4-3.0mm (FB 1.4-1.5mm). Malaysia (Pahang, Sabah). .................................. S. spongifera CAMERON
- Punctation of elytra less coarse, diameter of punctures less large than diameter of antennal segment 1............................................................................................................18
18. Aedeagus (fig. 73a). 2.3-3.0mm (FB 1.4-1.6mm). Indonesia (Java)................................ ......................................................................................................... S. javanus BERNHAUER
-: Aedeagus otherwise.....................................................................................................19
19: Aedeagus (fig. 74). 3.0mm (FB 1.5mm). N India .............................. S. lescheni nov.sp.
-: Aedoeagus (fig. 75). 2.4-3.1mm (FB 1.4-1.6mm). Indonesia (Lombok, Java)................ ................................................................................................................. S. sannifer PUTHZ
20 Abdominal punctation denser, interstices on tergite 7 at most as large as half diameter of punctures.: Median lobe (fig. 6, PUTHZ 1991) closely resembling that of S. javanus.: Spermatheca (fig. 7 l. c.). 3.4mm (FB 1.5-1.6mm). N India, Nepal ................... ................................................................................................................ S. sannator PUTHZ
- Abdominal punctation slightly less dense, interstices on tergite 7 occasionally as large as half diameter of punctures or slightly larger.: Aedeagus (fig. 6, PUTHZ 1980a). 2.7- 3,3mm (FB 1.5-1.6mm). N India, Nepal, China (Yunnan) ................... S. sannio PUTHZ
21 Legs dark...........................................................................................................................22
- Legs reddish yellow or reddish brown..............................................................................23
22 Head narrower (HW: EW<0.95). Elytra shorter (EW: EL 1.00).: Anterior portion of median lobe triangular (fig. 1, PUTHZ 1976a). Indonesia (Java) ........ S. flagellifer PUTHZ
- Head slightly broader (HW: EW>0.95). Elytra longer (EW: EL <0.95).: Aedeagus (fig. 89), median lobe with a long, strongly sclerotized tube. 4.2mm (FB 2.2mm). Indonesia (Sulawesi) ........................................................................ S. sulawesicola nov.sp.
23 Abdominal punctation dense or moderately dense............................................................24
- Abdominal punctation very sparse.: Aedeagus (fig. 2, PUTHZ 1980b). 4.0-4.5mm (FB 2.2mm). Philippines (Luzon, Negros, Imugan). .......................... S. aeratus L. BENICK
24 Abdominal tergites 3-6 with faint groundsculpture. Elytra about as long as broad. On average smaller.................................................................................................................25 Abdominal tergites 3-6 brilliant, without groundsculpture. Elytra longer than broad.: Aedeagus (fig. 88). 3.8-4.6mm (FB 2.5-2.6mm). Indonesia (Sulawesi, Maluku) .................. ............................................................................................................ S. quaesitus nov.sp.
25: Aedeagus (figs 80, 81). 3.7-4.3mm (FB 1.9-2.0mm). Malaysia (Pahang), Indonesia Sumatra) ........................................................................................... S. pastoralis CAMERON
-: Aedeagus (fig. 79). 3.3-4.1mm (FB 2.0-2.2mm). Malaysia (Sabah, Sarawak) ................ ..................................................................................................................... S. heissi PUTHZ
26 Elytral sculpture strongly vorticose...................................................................................27 - Elytra sculpture not vorticose, punctures mostly distinctly delimited...............................29
27 Abdominal punctation coarser, punctures in tergite 7 as large as basal cross section of antennal segment 3.: Aedoeagus (fig. 5, PUTHZ 1975). 4.8-6.7mm (FB 2.7-3.3mm). N India, Nepal, Bhutan ................................................................... S. sikkimensis CAMERON
- Abdominal punctation less coarse, punctures on tergite 7 distinctly smaller than basal cross section of antennal segment 3..................................................................................28
28 Elytra subquadrate, broader (HW: EW <0.85).: Aedoeagus (fig. 85). 4.5-6.5mm (FB 2.7-3.2mm). N India, Nepal, China (Yunnan)................................... S. tortuosus CAMERON
- Elytra subtrapezoid, less broad (HW: EW>0,90).: Aedoeagus (fig. 86). 5.0-6.0mm (FB 2.5-2.8mm). Nepal ................................................................... S. sulcatipennis nov.sp.
29 Punctation of frons less dense, interstices distinctly larger than half diameter of punctures. Aedoeagus (fig. 7, PUTHZ 1980b). 4.3-6.5mm (FB 2.6-2.8mm). Philippines (Luzon)............................................................................................. S. concavus L. BENICK
- Punctation of frons very dense, interstices smaller than half diameter of punctures.........30
30 Paratergites less broad, those of tergite 4 about as broad as antennal segment 1..............31
- Paratergites broader, those of tergite 4 distinctly broader than antennal segment 1..........32
31 Smaller.: Aedoeagus (fig. 38, PUTHZ 2008b). 4.2-5.5mm (FB 2.5-2.6mm). China (Yunnan, Sichuan, Hunan) ................................................................... S. fraterculus PUTHZ
- Larger.: Aedoeagus (fig. 39, PUTHZ 2008b). 4.8-6.2mm (FB 2.8-3.0mm). China (Taiwan) ................................................................................................ S. yanoianus PUTHZ
32 Elytra broader.: Aedoeagus (fig. 44, PUTHZ 2008b). 4.8-6.2mm (FB 2.7-2.8mm). China (Sichuan)...................................................................................... S. atrovestis PUTHZ
- Elytra less broad.: Aedoeagus (fig. 30, TANG & LI 2013). 67mm (FB 3.3mm). China (Ningxia) ...................................................................................... S. biwenxuani TANG & LI
33 Larger species: FB>2.5mm..............................................................................................34
- Smaller species: FB <2.5mm............................................................................................36
34 Segment 1 of metatarsi shorter than the 3 following segments combined.........................35
- Segment 1 of metatarsi longer than the 3 following segments combined.........................37
35 Legs reddish brown. Abdomen finely punctate, punctures smaller than basal cross section of antennal segment 3.: Aedeagus (fig. 4A, ROUGEMONT 1983b). 4.8-5.5mm (FB 2.7-3.0mm). Thailand, Nepal, N India ................... .............. S. lomholdti ROUGEMONT
- Legs blackish. Abdomen coarsely punctate, punctures on tergite 7 as large as basal cross section of antennal segment 3.: Aedeagus (fig. 36, PUTHZ 2008b). 5.0-5.5mm (FB 2.5-2.7mm). China (Yunnan) ..................................................... S. tenebricosus PUTHZ
36 Larger, with dark-blue metallic tint. Abdominal punctation very coarse, punctures on tergite 7 about as large as basal cross section of antennal segment 3.: Aedeagus (fig. 32, PUTHZ 1980b). 5.0-6.0mm (FB 3.0-3.2mm). China (Taiwan) ......................................... ................................................................................................... S. sauterianus BERNHAUER
- Smaller, without blue metallic tint: Abdominal punctation finer, punctures on tergite 7 distinctly smaller than basal cross section of antennal segment 3.: Aedeagus (fig. 33, PUTHZ 2008b). 4.5-5.5mm (FB 2.4-2.7mm). Japan ............................ S. kobensis CAMERON
37 Smaller species: FB 1.8mm.............................................................................................38
- Larger species: FB>2.0mm. Aedeagus without an expulsion clasp.................................39
38 Smaller species: FB 1.5mm. Aedeagus with an expulsion clasp (S. pusillus -group: palaearctic) S. escensus PUTHZ.: Aedeagus (fig. 9, PUTHZ 1970b). N India, Nepal; S. kishimotoianus PUTHZ.: Unknown. China (Sichuan); S. pernanus PUTHZ.: Aedeagus (fig. 6, PUTHZ 2006). China (Shaanxi); S. pusillulus PUTHZ.: Aedeagus (fig. 1, PUTHZ 1986b). Pakistan; S. simlaensis CAMERON.: Aedeagus (fig. 6, PUTHZ 1970b). N India; S. subescensus PUTHZ.: Aedeagus (fig. 14, PUTHZ 1976b). Nepal;
S. tumidicollis PUTHZ. Nepal; S. turgidicollis PUTHZ.: Aedeagus (fig. 3, PUTHZ 1986b). Pakistan.
- Larger species: FB>1.5mm. Aedeagus expulsion hooks (fig. 7, PUTHZ 2002b). 2.6- 3.3mm (FB 1.6-1.7mm). Vietnam ................ S. gibbicollis -group: palaearctic) S. lac PUTHZ
39 Elytra each with a reddish-yellow spot.............................................................................40
- Elytra without reddish spots..............................................................................................44
40 First segment of metatarsi distinctly longer than the three following segments combined...........................................................................................................................41
- First segment of metatarsi shorter or nearly as long the three following segments combined...........................................................................................................................42
41 Elytral spot very large, broader than half the breadth of elytron.: Aedeagus (fig. 34, PUTHZ 2008b). 4.5-6.0mm (FB 2.5-2.9mm). China (also Hainan) ........................................ .................................................................................................. S. huabeiensis ROUGEMONT
- Elytral spot smaller than half the breadth of elytron.: Aedeagus (fig. 35, l. c.). 4.0- 5.0mm (FB 2.4-2.5mm). China (Sichuan)............................................ S. falsiloquax PUTHZ
42 Lateral portions of frons sparsely punctate, interstices at least as wide as diameter of punctures...................................(S. comma -group)...........................................................43
- Lateral portions of frons densely punctate, interstices smaller than diameter of punctures.: Aedeagus (fig. 12, Puthz 2008b). China (Yunnan, Sichuan).......................... .................................. ............................................................................ S. bioculatus PUTHZ
43 Larger: 4.3-5.5mm. Elytral punctation very dense, punctures distinctly delimited, interstices shining.: Aedeagus (fig. 11, l. c.), apical setae of parameres very long 4.0-5.0mm. China (Fujian, Yunnan, Jiangsu, Guizhou, Jilin), Japan ....... S. tenuipes SHARP
- Smaller: 3.4-4.2mm. Elytral punctation extremely dense, rough, punctures less distinctly delimited, interstices totally dull (general impression: structure like charcoal).: Aedeagus (fig. 13, l. c.), apical setae of parameers short. China (Yunnan, Sichuan) ................................................................................................................................. ............................................................................................................. S. scabratus PUTHZ
44 Abdomen nearly cylindrical, paratergites of tergite 4 narrower than antennal segment 2, directed ventrad.: Aedeagus (fig. 37, l. c.). 4.2-5.1mm (FB 2.4mm). China (Taiwan) ................................................................................................................................. ............................................................................................................. S. insulanus PUTHZ
- Abdomen broadly-elliptical, paratergites broader, paratergites 4 as broad or broader thanantennal segment 2, directed dorsad or horizontally ...................................................... ................................(S. seminiger -group, S. comma -group p. p.: see PUTHZ 1980b, 2008b) S. confluens CAMERON.: Aedeagus (fig. 11, PUTHZ 1980b). N India; S. erythrocnemus EPPELSHEIM.: Aedeagus (Abb. 2, PUTHZ 1970d), Aserbeidschan, Armenia, Turkey, Iran, Tadzhikistan, Afghanistan, Pakistan; S. hirthei PUTHZ.: Aedeagus (fig. 2, PUTHZ 2003b). Nepal; S. holzschuhi PUTHZ.: Aedeagus (fig. 1, PUTHZ 1988b). Nepal; S. imitatus PUTHZ.: Aedeagus (fig. 10, PUTHZ 1980b). N India; S. insignatus PUTHZ.: Aedeagus (figs 16, 17, PUTHZ 20008). Vietnam, China (Hainan); S. insulanus PUTHZ.: Aedeagus (fig. 1, PUTHZ 1971c). China (Taiwan); S. jaegeri PUTHZ.: Aedeagus (fig. 3b, PUTHZ 2003b). Nepal; S. kurilensis PUTHZ.: Unknown. Kuriles; S. nitidiceps PUTHZ.: Aedeagus (fig. 15, PUTHZ 1980b). N India, Pakistan, Nepal; S. plumbativestis PUTHZ.: Aedeagus (figs 22, 23, PUTHZ 2010). China (Yunnan); S. plumbatus PUTHZ.: Aedeagus (fig. 14, PUTHZ 1980b). N India; S. plumbarius PUTHZ.: Aedeagus (fig. 42, PUTHZ 2008b). China (Yunnan); S. plumbeus CAMERON.: Aedeagus (fig. 1, PUTHZ 1968b; figs 12, 13, PUTHZ 1980b). Afghanistan, Pakistan, India, Nepal, Bhutan, China (Sichuan, Yunnan); S. plumbivestis PUTHZ.: Aedeagus (fig. 41, PUTHZ 2008b). China (Taiwan); S. seminiger CHAMPION.: Aedeagus (about as in fig. 10, PUTHZ 1980b). N India, Nepal, Bhutan.
45 Base of anterior tergites with 3 carinae.............................................................................46
- Base of anterior tergites with 4 carinae. 2.4-3.5mm (FB 1.4-1.7mm). India, Nepal, Myanmar, Thailand, Laos, Vietnam, China (Yunnan), Indonesia (Timor), Philippines ....... .......................................................................................... S. melanarius annamita FAUVEL
46 Tergite 10 with a spot of dense and shiny pubescence. Mostly smaller species (S. circularis- group [= S. rugicollis -group]), key see PUTHZ 2003b S. adebratti nov.sp..: Aedeagus (fig. 92). Malaysia (Sabah); S. adjunctus PUTHZ.: Aedeagus (figs 9, 10, PUTHZ 1991). Nepal; S. baliensis ROUGEMONT.: Aedeagus (fig. 1, ROUGEMONT 1984). Indonesia (Bali); S. beesoni CAMERON.: Aedeagus (figs 14, 15, PUTHZ 1968b). N India, Myanmar, Thailand; S. boholensis nov.sp..: Aedeagus (fig. 94). Philippines (Bohol); S. brookeianus ROUGEMONT.: Unknown. Brunei; S. calcarifer PUTHZ.: Aedeagus (figs 12, 13, PUTHZ 1991). N India; S. carinatus CAMERON.: Aedeagus (fig. 1, PUTHZ 1971a). Sri Lanka; S. chatterjeei CAMERON.: Aedeagus (fig. 2, l. c.). N India; S. concavifrons PUTHZ.: Aedeagus (figs 9, 10, PUTHZ 2003b). Indonesia (Java); S. diffidens CAMERON.: Aedeagus (figs 9, 10, PUTHZ 1968b). N India, Nepal, Myanmar, Thailand, Laos; S. duplopunctatus BERNHAUER. Philippines (Luzon, Mindanao), Indonesia (Sumatra, Java), Malaysia (Sabah); S. falsidicus PUTHZ.: Aedeagus (fig. 11, PUTHZ 1991). N India; S. floresicus PUTHZ.: Aedeagus (fig. 12, PUTHZ 2003b). Indonesia (Flores); S. geiseri nov.sp..: Aedeagus (fig. 95). Laos; S. helleri L. BENICK.: Aedeagus (fig. 13, PUTHZ 1968b). Indonesia (Sulawesi); S. helvitarsis PUTHZ.: Unknown. Philippines (Mindoro) S. indicus PUTHZ.: Aedeagus (figs 19, 20, PUTHZ 1968b). Bangladesh ("Bengala"),? China (Yunnan); S. indignandus PUTHZ.: Aedeagus (fig. 7, PUTHZ 2003b). Indonesia (Sumatra); S. infaustus nov.sp.: Aedeagus (fig. 96). Laos; S. jaechi PUTHZ.: Aedeagus (fig. 8, l. c.). Malaysia (Sarawak); S. louwerensi CAMERON.: Aedeagus (figs 16, 17, PUTHZ 1968b). Indonesia (Java, Sulawesi),? Philippines (Luzon), Thailand, Laos, Vietnam; S. megacephalus CAMERON.: Aedeagus (fig. 7A, ROUGEMONT 1981b). Malaysia, Indonesia (Sumatra, Java), Myanmar, Thailand, Laos, Vietnam, China (Yunnan); S. molestus PUTHZ.: Aedeagus (figs 4, 5, PUTHZ 2003b). Nepal; S. mon ROUGEMONT.: Aedeagus (fig. 10, ROUGEMONT 1981b). Thailand, Myanmar, Laos; S. notabilifrons nov.sp.. Malaysia; S. rugicollis KRAATZ.: Aedeagus (fig. 93). India, Myanmar, Thailand, Laos, Vietnam; S. skalei nov.sp..: Aedeagus (figs 90, 91). Indonesia (Sulawesi); S. sumbaensis SCHEERPELTZ.: Aedeagus (fig. 1, SCHEERPELTZ 1957). Indonesia (Sumba); S. timoricus PUTHZ.: Aedeagus (fig. 3, PUTHZ 1966). Indonesia (Timor).
- Tergite 10 without a shiny spot of dense and shiny pubescence.......................................47
47 Sternum 9 apically serrate, smaller species..............................................(S. humilis -group) No Oriental species, but several species in China and Japan
- Sternum 9 acute apicolaterally, larger species (S. clavicornis -group)...............................48 The following species of China, Korea and Japan, which belong to the palaearctic fauna are not included here: S. calliceps BERNHAUER (China, Japan), S. clavicornis (SCOPOLI) (Holarctis, Japan), S. disterminus PUTHZ (Japan), S. indagator EPPELSHEIM (Russia, China, Japan), S. kamtschaticus MOTSCHULSKY (China, Russia, Mongolia), S. lewisius SHARP (Japan), S. lewisius pseudoater BERNHAUER (China, Korea), S. mongolicus EPPELSHEIM (China (Sichuan, Xizang, Qinghai, Gansu, Xinjiang), Kazakhstan, Turkmenistan, Tadzhikistan, Uzbekistan, Kyrgyzstan, Iran, Afghanistan, Pakistan, Ladakh, Kashmir, SE Russia), S. nishikawai NAOMI (Japan), S. paradoxus Bernhauer (China, Russia), S. sauteri BERNHAUER (Japan, Korea, Russia), S. secretus BERNHAUER (Russia, China, Mongolia), S. ussuriensis RYVKIN (Russia, China), S. yamato NAOMI (Japan) (see PUTHZ 2013b)
48 Elytra each with a reddish yellow spot..............................................................................49
- Elytra without a reddish yellow spot.................................................................................50
49 Median portion of frons distinctly elevate, longitudinal furrows deep.: Apical portion of median lobe not broadened...............................................................................51
- Median portion of frons indistinctly elevated, longitudinal furrows shallow.: Apical portion of median lobe broadened (fig. 1, HROMÁDKA 1980). 4.5-5.3mm (FB 2.5- 2.6mm). N India, Pakistan, Afghanistan ............................................ S. bengle HROMÁDKA
50 Elytral spot in about middle of elytra (fig. 27, PUTHZ 2010).: Metafemora simple. Aedeagus (fig. 25, l. c.). 4.5-5.5mm (FB 2.3-2.5mm). N India, Pakistan, Nepal, China (Yunnan) ........................................................................................... S. kraatzi BERNHAUER
- Elytral spot in posterior half of elytra (fig. 28, l. c.).: inner side of metafemora densely furnished with long setae. Aedeagus (fig. 24, l. c.). 4.8-6.0mm (FB 2.4- 2.6mm). China (Shaanxi, Sichuan) ................................................. S. lanuginosipes PUTHZ
51 Paratergites broader, directed horizontally, paratergite 4 broader than antennal segment 1........................................................................................................................................52
- Paratergites less broad, directed ventrad, paratergite 4 at most as broad as antennal segment 1..........................................................................................................................53
52 Elytra with a small rosette of curved sulci medially.: Metafemur with a spine basally (fig. 29, l. c.). Aedeagus (fig. 26, l. c.). 3.8-4.5mm (FB 2.0mm). China (Sichuan, Yunnan)................................................................................................. S. spinulipes PUTHZ
- Elytra without a rosette medially.: Metafemur simple. 3.5-4.2mm (FB 2.2mm). Aedeagus (fig. 2, PUTHZ 2006). Indonesia (Java)..................................... S. desertor PUTHZ
53 Elytral sculpture strongly rugose/vorticose.......................................................................54
- Elytra very densely punctate, occasionally slightly rugose...............................................55
54 Head broader than elytra, paratergites indistinctly delimited, evanescent.: Aedeagus (fig.1, PUTHZ 2006). 4.0-5.2mm (FB 2.2mm). China (Taiwan) ............ S. pseudolus PUTHZ
- Head narrower than elytra, paratergites narrow but distinctly delimited.: Aedeagus (fig. 84). 4.0-5.5mm (FB 2.7mm). China (Taiwan, Hongkong, Fujian, Chongqing, Jiangsu), Vietnam, Japan ............................................................... S. formosanus L. BENICK
55 Abdominal punctation denser, tergite 7 matt, interstices much smaller than half diameter of punctures.: Median lobe slightly longer than parameres. 4.5-6.0mm (FB 2.1-2.6mm). Indien, Myanmar, Thailand, Vietnam ................................. S. venator FAUVEL
- Abdominal punctation less dense, tergite 7 shiny, interstices larger than half diameter of punctures.: Median lobe distinctly shorter than parameres. 4.0-5.0mm (FB 2.5mm). Japan, Korea, Russia, China (Fujian, Hainan, Hubei, Sichuan, Shaanxi, Beijing) ...................................................................................................... S. distans SHARP
B. Key to the groups of Oriental species of the genus Stenus with margined abdomen and bilobed tarsi
1 Head with very large eyes, average breadth of frons at most half the width of head (figs 1, 2). Large species, FB> 2.0mm (habitus see also fig. 81, PUTHZ 1969). Paraglossae oval......................................................................................................................................2
- Head with smaller eyes (e. g. fig. 3), average distance between eyes broader than half the width of head. Species of various sizes. Paraglossae oval, coniform or sileniform.......4
2 Sternum 9 apicolaterally acute (figs 54, 55), frons deeply concace, median portion not or only slightly elevated......................................................................................................3 - Sternum 9 apicolaterally serrate (fig. 69), frons deeply concave, median portion strongly elevated .............................................................................................. S. feae group
3: Legs simple, E: median lobe with a small triangular expulsion hook (e. g. figs 256- 260), parameres setaceous along whole internal side.: S (about as in figs 261, 262, 263, 273....................................................................................................... S. gestroi -group
-: Legs with preapical/apical spurs, E: median lobe with a large expulsion clasp (e. g. figs 268-270, 275), parameres setaceous at apex.: S (about as in fig. 274)....................... ............................................................................................................. S. guttalis -group pp.
4 Sternum 9 apicolaterally ± serrate (figs 35-38, 60, 64, 67, 68)...........................................5 (note: this characters sometimes is barely noticable: e. g. fig. 31)
- Sternum 9 apicolaterally acute (figs 29, 66)........................................................................7 [In some species with strongly vorticose elytral sculpture (S. scopulus -group) this character may be dubious: see below]
5 Paraglossae oval (fig. 15). Paratergites mostly less broad than antennal segment 2. Species of various lengths...................................................................................................6
- Paraglossae coniform (fig. 14). Paratergites distinctly broader than antennal segment, 2. Large species, FB>2.6mm............................................................... S. stigmaticus -group
6: Median lobe without expulsion hooks or expulsion clasp (e. g. figs 307, 310, 311, 315); some setae of parameres often with a rough surface (figs 313, 314).: Spermatheca weakly sclerotized, very small, indistinct (fig. 308). Abdominal margination narrow, paratergites less broad than antennal segment 2, nearly impunctate, or absent (margination reduced to a simple line)............................... S. tenuimarginalis -group
-: Median lobe with expulsion hooks and/or expulsion clasp (can be very small, e. g. in S. dapitananus BERNHAUER, S. gardneri CAMERON (fig. 301) and in S. montivagans CAMERON); surface of parameral setae smooth. Abdominal margination mostly as broad as antennal segment 2, mostly punctate ............................................ S. virgula -group
7 Paraglossae coniform (fig. 14) ............................................................ S. abdominalis -group (note: species of the S. stigmaticus- group also have coniform paraglossae)
- Paraglossae otherwise (mostly oval)...................................................................................8
8 Species with spotted elytra (1 exception: S. solstitialis ZHENG). Species of different phylogenetic groups ............................................................................................................9
- Species with non-spotted elytra.........................................................................................10
9: S proximately with a rattlesnake’s tail-like duct (fig. 403)............. S. tenuimargo -group
-: S proximately with a swollen chamber (fig. 309)............................... S. indubius -group
10 Paratergites in horizontal position.....................................................................................11
- Paratergites declining ventrad or only line-like.................................................................14
11 Greenish metallic, paratergites in horizontal position, broader than antennal segment 2, tarsi shorter (length of metatarsi: length of metatibiae  0,85) ............... S. viridanus -group
- Blackish or with a bronze tint...........................................................................................12
12 Posterior margin of frons straight or slightly concave (figs 4, 5)......................................13
- Posterior margin of frons strongly concave (fig. 407 ....................... S. perplexus- group p.p.
13 Blackish, elytra strongly vorticose.: Spermathecal duct shorter, (mostly) bag-like swollen before collum (fig. 408) .............................................................. S. scopulus -group
- Metallic with bronze tint.: Spermathecal duct longer, thin and multiply coiled, not swollen before collum (figs 278, 406).................................................... S. impressus -group
14 Larger species, FB 2.8mm. Elytral sculpture strongly vorticose...... S. rugosipennis -group
- Smaller species, FB 2.5mm. Elytral sculpture not strongly vorticose.............................15
15 Apicolateral tooth of sternum 9 not claw-shaped and not directed ventrad. Paraglossae oval......16
- Apicolateral tooth of sternum 9 claw-shaped, directed ventrad (fig. 400). Paraglossae silaniform (figs 16, 17, 376).................................................................... S. pilicornis -group
16 One species from Thailand.: Aedoeagus (Abb. 412). 3.0-4.0mm (FB 2.1mm).................. ............................................................................................................. S. falcipenis PUTHZ
- Species from other countries.............................................................................................17
17 Species from Taiwan ...................................................................... S. cephalotes -group p.p.
- Species from S-India or Sri Lanka ..................................................... S. brachypterus group
C. Key to the Oriental species of the genus Stenus with unmargined abdomen and bilobed tarsi
(note: unmargined abdomen = no paratergites and no separation line on segments 4-6)
1 Tergite 10 with special characters (bicuspid, bifurcate, anchoriform: figs 167-191) [exceptions: S. aericeps BERNHAUER (fig. 187), S. pernix L. BENICK (fig. 168), S. scitulus L. BENICK (fig. 169), with a very broad frons: HW: gDE <1.80].: Legs without any special sexual characters. FB 1.3- 2,2mm ............................... S. rorellus -group (revision of the group see below)
- Tergite 10 otherwise............................................................................................................2
2 Tergite 10 apicolaterally roundly projecting, concave apicomedially (figs 48, 49). Frons comparatively narrow, pronotum slightly longer than broad. FB 1.9-2.1mm ............. ............................................................................................................... S. wasmanni -group
- Tergite 10 rounded apically................................................................................................3
3 Tergite 8 with a posteromedian patch of dense shiny setae (figs 9, 12, 13)........................4
- Tergite 8 without a posteromedian patch of dense shiny setae...........................................8
4 Sternum 9 with a very long apicolateral tooth (figs 28, 57) ...................... S. bispinus -group
- Sternum 9 otherwise............................................................................................................5
5 Sternum 9 of (fig. 61) [of serrate]....................... (S. pulcher -group). S. changi PUTHZ
- Sternum 9 of otherwise...................................................................................................6
6 Sternum 9 with a moderately long apicolateral tooth (fig. 53).......... S. cicindeloides -group
- Sternum 9 serrate apicolaterally or with a very short apicolateral projection (fig. 56).......7
7 Antennae very slender, when reflexed extending beyond the posterior margin of pronotum, penultimate segments much longer than broad. Antennae and legs yellowish .... ............................................................................................................. S. coelogaster -group
- Antennae short, when reflexed extending to about middle of pronotum, penultimate segments broader than long. Antennae and legs predominantly dark ................................... .......................................................................................................... S. periscelidifer- group
8 Sternum 9 serrate apically (figs 63, 65, 225).......................................................................9
- Sternum 9 acute apicolaterally (figs 33, 34, 227)..............................................................11
9 Sternum 9 with an apicolateral brush about half as long as the sternum (fig. 225). Pronotum comparatively short (PL: PW <1.3). Smaller species: FB 1.8-2.3mm.................. .................................................................................................................. S. leptopus -group
- Sternum 9 not or only with a short apicolateral brush. Pronotum short or longer. On average larger species.......................................................................................................10
10 Pronotum much longer than broad (PL: PW>1.3).: Legs simple. E: Median lobe in most cases without a flagellum ......................................................... S. cylindricollis -group
- Pronotum shorter (PL: PW <1.25).: Legs often with special sexual characters. E: Median lobe often with a flagellum ..................................................... S. pulcher -group pp.
11 Abdomen with conspicuously long and erect setae (figs 6, 7) ................ S. cirrus- group pp.
- Abdomen not with conspicuously long and erect setae.....................................................12
12 Sternum 9 with a very long apicolateral tooth (fig. 30).....................................................13
- Sternum 9 with a shorter apicolateral tooth (figs 33, 34)..................................................14
13 Larger species: FB>2.5mm. Frons concave, without distinct shiny plaques......................... ..... S. azurescens -group (probably a mixed group of different phylogenetic relationships)
- Smaller species: FB 2.2mm. Frons convex, with distinct shiny plaques. S. piliferus -group
14 Larger species, FB 1.9mm..............................................................................................15
- Smaller species: FB <1.9mm ................................................................ S. cephalotes- group (mixed group, probably phylogenetically belonging to species groups with margined abdomen)
15 Sternum 9 apicolaterally acutely ± prominent (figs 52, 54)..............................................16
- Sternum 9 apicolaterally less and roundly prominent (fig. 51) ................. S. lampros- group
16 Smaller species, FB <2.2mm.: No sclerotized spermatheca ............ S. pulcher- group pp.
- Larger species, FB>2.6mm.: With a sclerotized spermatheca (figs 263, 274)................. ................................................................................................................... S. guttalis- group
description: Published as part of Puthz, V., 2013, Übersicht über die orientalischen Arten der Gattung Stenus LATREILLE 1797 (Coleoptera, Staphylinidae) 330. Beitrag zur Kenntnis der Steninen, pp. 1279-1470 in Linzer biologische Beiträge 45 (2) on pages 1284-1293, DOI: 10.5281/zenodo.5300922