Stenus

Liang, Tang, Zhao, Yun-Long & Puthz, Volker, 2008, Six new Stenus species of the cirrus group (Coleoptera, Staphylinidae) from China with a key to species of the group, Zootaxa 1745, pp. 1-18 : 14-16

Key to Stenus species of the cirrus group

1 Paraglossae oval ( cirrus -complex) ............................................................................................................. 2

- Paraglossae coniform ( flammeus -complex) ( Hypostenus ).......................................................................28

2 Third abdominal tergite without paratergites ( Hypostenus )........................................................................3

- Third abdominal tergite with paratergites....................................................................................................5

3 Elytra unicolorous; front narrower (FW: HW = 0.42). Spermatheca as in Fig. 13 (in Puthz 2003). Male unknown. BL: 3.0– 4.2 mm. China: Hainan ........................................................... S. fellowesi Puthz, 2003

- Elytra bicolorous; front broader (FW: HW>0.44).................................................................................... 4

4 Forebody with interstices reticulately sculptured; pronotum and elytra slightly glossy with punctation very dense; abdominal punctation moderately coarse. Spermatheca as in Fig. 14 (in Puthz 2003). Male unknown. Bl: 3.0– 4.2 mm. China: Hainan ....................................................... S. hainanensis Puthz, 2003

- Forebody with interstices smooth; pronotum and elytra glossy with punctation less dense; abdominal punctation fine to very fine. Aedeagus as in Fig. 6 (in Puthz 1981). BL: 4.0–5.0 mm. Vietnam............... .......................................................................................................................... S. echiniventris Puthz, 1981

5 Only 3rd abdominal tergite with complete paratergites. Elytra with or without spots ( Hypostenus ) ........ 6

- Abdominal tergites 4–6 with narrow to very narrow linear margination ( Hemistenus ). Elytra unicolorous, without elytral spots.................................................................................................................................. 25

6 Elytra unicolorous, without elytral spots.....................................................................................................7

- Elytra bicolorous, with elytral spots..........................................................................................................12

7 Elytral punctures distinctly delimited, moderately deep; punctation of frons coarse and moderately dense 8

- Elytral punctures indistinctly delimited, shallow; punctation of frons less coarse, sparse. Aedeagus as in Fig. 1 , E (in Naomi 1988); spermatheca as in Fig. 1 , F (in Naomi 1988). BL: 3.0– 3.8 mm. Japan: Amami- Oshima Is. ........................................................................................................ S. amamiensis Naomi, 1988

8 Male: aedeagus as in Fig. 1 , D (in Naomi 1998), apical portion of median lobe triangular, longer than broad. BL: 3.0– 3.8 mm. Japan: Nansen Isls.: Toku Is............................................ S. tokunis Naomi, 1998

- Male: aedeagus as in Fig. C (in Naomi 1988), apical portion of median lobe spade-like, broader than long. BL: 3.2–4.1 mm. Japan: Okinawa-Hontô Is. ........................................................ S. punctifer Naomi, 1988

9 Smaller species; elytra broader than long.................................................................................................10

- Larger species, elytra at least as long as wide. Aedeagus as in Fig. 12 (in Puthz 1998a), spermatheca as in Fig. 5 (in Puthz 1998a). BL: 3.2–4.2 mm. Vietnam.......................................... S. deliculus Ryvkin, 1992

10 Punctation of forebody moderately dense, interstices strongly glossy, punctures distinctly delimited. Aedeagus as in Fig. 26 (in Puthz 2003). BL: 2.5–3.5 mm. China: Jiangsu .......... S. falsus L. Benick, 1940

- Punctation of forebody very dense, interstices slightly or not glossy, punctures less distinctly delimited .. 11

11 Interstices of pronotal punctation distinctly reticulate. Aedeagus as in Fig. 22 , spermatheca as in Fig. 24 . BL: 2.3–2.8 mm. China: Zhejiang ......................................................................... S. shenshanjiai sp. nov.

- Interstices of pronotal punctation indistinctly reticulate. Aedeagus as in Fig. 10 (in Tang et al. 2005), spermatheca as in Fig. 11 (in Tang et al. 2005). BL: 2.3–3.2 mm. China: Shaanxi ............................................ .......................................................................................................................... S. nigritus Tang et al., 2005

12 Head distinctly wider than elytra...............................................................................................................13

- Head narrower than elytra or nearly as wide as elytra..............................................................................21

13 Frons with punctation sparse and different in size. Aedeagus as in Fig. 12 (in Puthz 2003). BL: 3.0–4.0 mm. China: Guangdong ..................................................................................... S. cactiventris Puthz, 2003

- Frons with punctation dense and almost same in size...............................................................................14

14 Punctation of pronotum and elytra very dense, crowded, that of the pronotum irregular. Species best identified by their sexual characters ................................................................................................................ 15

- Punctation of pronotum and elytra dense but not crowded.......................................................................19

15 Punctation of elytra very densely crowded. Male: apical emargination 8th abdominal sternite very broad and shallow ( Fig. 7 )...................................................................................................................................16

- Punctation of elytra less dense, less crowded. Male: apical emargination of 8th abdominal sternite narrower, rounded ( Figs. 12, 14 ) (exceptions: S. cooterianus , S. ovalis )......................................................17

16 Elytral spot shorter, not extending towards shoulder. Aedeagus as in Fig. 9 , spermatheca as in Fig. 11 . BL: 3.7–5.0 mm. China: Zhejiang ...................................................................................... S. zhulilongi sp. nov

- Elytral spot longer, extending towards shoulder. Aedeagus as in Fig. 20 (in Puthz 2003), spermatheca as in Fig. 19 (in Puthz 2003). BL: 3.5–4.7 mm. China: Fujian............................. S. lacrimulus L. Benick, 1942

17 Elytral spot shorter than half elytron length. Punctation of pronotum homogenous, very coarse. Aedeagus as in Fig. 18 . BL: 3.7–5.0 mm. China: Zhejiang ................................................. S. jiulongshanus sp. nov.

- Elytral spot longer than half elytron length .............................................................................................. 18

18 Body smaller, punctation of pronotum inhomogenous, with moderately coarse and very coarse punctures. Aedoeagus as in Fig. 18 (in Puthz 2003). BL: 3.6–4.3 mm. China: Fujian ........... S. wuyiensis Puthz, 2003

- Body larger, punctation of pronotum homogenous, very coarse. Aedeagus as in Fig. 14 . BL: 3.8–5.0 mm.

China: Jiangxi, Zhejiang ................................................................................................ S. lijinweni sp. nov. 19 Punctation on elytral spot very sparse, some interstices larger than diameter of punctures. Aedeagus as in Fig. 9 (in Puthz 2003). BL: 3.2–4.2 mm. China: Fujian.................................... S. cooterianus Puthz, 2003

- Punctation on elytral spot dense, interstices slightly larger than half diameter of punctures....................20

20 Body larger: 3.8–4.5 mm (forebody: 1.9–2.1 mm). Elytral spot longer than half elytron, extending towards shoulder. Aedeagus as in Fig. 14 (in Tang et al. 2005), spermatheca as in Fig. 15 (in Tang et al. 2005). BL: 4.1–4.7 mm. China: Zhejiang ........................................................................... S. ovalis Tang et al., 2005

- Body smaller: 3.2–4.1 mm (forebody: 1.6–1.7 mm). Elytral spot shorter than half elytron length, not extending towards shoulder. Aedeagus as in Fig. 6 (in Tang et al. 2005), spermatheca as in Fig. 7 (in Tang et al. 2005). BL: 3.6–4.3 mm. China: Hubei ..................................................... S. andoi Tang et al., 2005

21 Head scarcely wider than elytra; elytra broader than long; elytral spot indistinctly delimited. Aedeagus as in Fig. 1 (in Puthz, 1983). BL: 3.0– 3.5 mm. China: Guangxi .......................... S. splendidulus Puthz, 1983

- Head distinctly narrower than elytra; elytra longer than broad. Four very similar species with larger body...................................................................................................................................................................22

22 Elytral spot very large, extending towards shoulder ( Fig. 1 in Hromádka 2001)......................................23

- Elytral spot smaller, not extending towards shoulder. Aedeagus as in Fig. 2 (in Puthz 1998b). BL: 3.8–4.8 mm. Vietnam.................................................................................................... S. aeneofulgens Puthz, 1998

23 Punctation of elytra very dense, crowded. Abdominal punctation denser, interstices on 7th tergite at most twice as wide as punctures. Aedeagus as in Fig. 2 (in Hromádka 2001), spermatheca as in Fig. 4 (in Hromádka 2001). BL: 3.7–4.7 mm. India: Uttar Pradesh ............................. S. panthera Hromádka, 2001

- Punctation of elytra less dense, not crowded. Abdominal punctation sparser, interstices on 7th tergite three times as wide as punctures........................................................................................................................24

24 Male: aedeagus as in Fig. 3 (in Puthz 1998b). BL: 3.5–4.7 mm. China: Guangxi, Zhejiang........................ ................................................................................................................ S. guangxiensis Rougemont, 1984

- Male: aedeagus as in Fig. 4 (in Puthz 1998b). BL: 3.3–4,7 mm. China: Sichuan......................................... ........................................................................................................................... S. aeneonitens Puthz, 1998

25 Body smaller: 2.6–3.6 mm ........................................................................................................................26

- Body larger: longer than 3.4 mm ................................................................................................................... .... Seven Japanese species: S. cirriformis Naomi, 1988 ; S. domburi Hromádka, 1979 ; S. kanzeon Naomi, 2004 ; S. longisetosus Puthz, 1993 ; S. nachiensis Puthz, 2001 ; S. nyorin Naomi, 2004 ; S. sakaii Naomi & Puthz, 1996 ; S. sawadaianus Hromádka, 1979 ; S. sugiei Naomi, 1997 .

26 Elytra strongly glossy with punctation irregular, slightly confluent, interstices smooth. Aedeagus as in Fig. 16 (in Puthz 2003), spermatheca as in Fig. 15 (in Puthz 2003). BL: 2.6–3.4 mm. China: Jiangxi ....... ................................................................................................................ S. huangganmontium Puthz, 2003

- Elytra slightly glossy with punctation regular and deep, scarcely confluent.............................................27

27 Frons nearly dull with punctation very dense. Aedeagus as in Fig. 37 , spermatheca as in Fig. 39 . BL: 2.6– 3.6 mm. China: Zhejiang .................................................................................... S. cirrus L. Benick, 1940

- Frons glossy with punctation sparse. Aedeagus as in Fig. 1 , D (in Naomi 1988), spermatheca as in Fig. 1 , E (in Naomi 1988). BL: 2.6–3.2 mm. Japan.............................................. S. yashiro Naomi & Puthz, 1994

28 Body broader and larger. Punctation of 6th and 7th abdominal tergites denser, interstices at most as large as punctures. Aedeagus as in Fig. 27 , spermatheca as in Fig. 29 . BL: 3.7–5.7 mm. China: Sichuan ........... ...................................................................................................................................... S. flammeus sp. nov.

- Body narrower and slightly smaller. Punctation of 6th and 7th abdominal tergites less dense, interstices up to twice as large as punctures. Aedeagus as in Fig. 32 , spermatheca as in Fig. 34 .BL: 4.0– 4.5 mm. China: Sichuan ....................................................................................................................... S. bostrychus sp. nov.

Figures

FIGURES 12 – 15. Details of Stenus lijinweni sp. nov. 12 — male 8 th sternite; 13 — male 9 th sternite; 14 — aedeagus in ventral view; 15 — expulsion clasp of aedeagus. Scale bars 0.25 mm.

FIGURES 1 – 6. Stenus cirrus group, habitus. 1 — S. zhulilongi sp. nov., female; 2 — S. lijinweni sp. nov., male; 3 — S. jiulongshanus sp. nov., male; 4 — S. shenshanjiai sp. nov., male; 5, S. — flammeus sp. nov., male; 6 — S. bostrychus sp. nov., male. Scale bars 1 mm.

FIGURES 25 – 29. Details of Stenus flammeus sp. nov. 25 — male 6 th – 8 th sternites; 26 — male 9 th sternite; 27 — aedeagus in ventral view; 28 — expulsion clasp of aedeagus; 29 — spermatheca. Scale bars 0.25 mm.

FIGURES 20 – 24. Details of Stenus shenshanjiai sp. nov. 20 — male 8 th sternite; 21 — male 9 th sternite; 22 — aedeagus in ventral view; 23 — expulsion clasp of aedeagus; 24 — spermatheca. Scale bars 0.25 mm.

FIGURES 7 – 11. Details of Stenus zhulilongi sp. nov. 7 — male 8 th sternite; 8 — male 9 th sternite; 9 — aedeagus in ventral view; 10 — expulsion clasp of aedeagus; 11 — spermatheca. Scale bars 0.25 mm.

FIGURES 16 – 19. Details of Stenus jiulongshanus sp. nov. 16 — male 6 th – 8 th sternites; 17 — male 9 th sternite; 18 — aedeagus in ventral view; 19 — expulsion clasp of aedeagus. Scale bars 0.25 mm.

FIGURES 35 – 39. Details of Stenus cirrus L. Benick. 35 — male 8 th sternite; 36 — male 9 th sternite; 37 — aedeagus in ventral view; 38 — expulsion clasp of aedeagus; 39 — spermatheca. Scale bars 0.25 mm.

FIGURES 30 – 34. Details of Stenus bostrychus sp. nov. 30 — male 7 th – 8 th sternites; 31 — male 9 th sternite; 32 — aedeagus in ventral view; 33 — expulsion clasp of aedeagus; 34 — spermatheca. Scale bars 0.25 mm.