Stenus guttalis FAUVEL 1895

Puthz, V, 2011, On the Stenus LATREILLE 1797 from Taiwan with spotted elytra including remarks on the S. gestroi-group (Coleoptera, Staphylinidae) (316 Contribution to the Knowledge of Steninae), Linzer biologische Beiträge 43 (1), pp. 565-596 : 592-594

Stenus guttalis FAUVEL 1895 ( Fig. 10 )

Stenus guttalis FAUVEL 1895: 212 ; PUTHZ 1969: 21 f. figs.

M a t e r i a l s t u d i e d from Taiwan: Taichung Hsien: 1, 2: Wufeng , 100-120 m, 14.IV.1990, A. Smetana (T 1) (cS, cP) ; Taitung Hsien: 1: Peiyuan , 7.VI.1968, Y. Watanabe (cP) .

This species was described from Burma and is known to me from Laos, Thailand, China (Yunnan), Japan (Okinawa Pref.), Malaysia, Sabah, Sumatra and Bali. It resembles strongly S. gestroi but has the abdomen immargined.

Key to the Tawanese Stenus species with spotted elytra (A = aedeagus; EC = expulsion clasp; S= spermatheca)

1 Abdomen margined.............................................................................................................2

- Abdomen unmargined.......................................................................................................25

2 Abdominal segments 4-7 very narrow, thread-like margined, without paratergites............3

- Abdominal segments 4-7 with distinct paratergites.............................................................9

3 Abdominal pubescence long and erect................................................................................4

- Abdominal pubescence short and recumbent......................................................................5

4 Larger: 4.0-5.0 mm (FB: 2.0 mm). Elytral spot distinct, longer, extending from shoulder to posterior margin.: Unknown.: S (fig. 25, PUTHZ 2009).............................. ........................................................................................................... S. cirrativestis PUTHZ

- Smaller: 3.0-4.0 mm (F: 1.8 mm). Elytral spot less distinct, smaller, in posterior half of elytra.: A(fig. 114).: Unknown .................................................... S. cirricinctus PUTHZ

5 Elytra distinctly broader than long; eyes very large, frons strongly concave.: A (figs 46-54, 56).: S (fig. 8). 4.8-6.5 mm (FB: 2.3-2.7 mm) .......................... S. gestroi FAUVEL

- Elytra longer than broad, eyes less large, frons shallowly concave, median portion distinctly elevated...............................................................................................................6

6 Elytra longer (EW: EL<0.92 [0.88-0.94]), elytral spot distinctly extending into anterior half of elytra........................................................................................................................7

- Elytra shorter (EW: EL>0.92 [0.93-0.98]).........................................................................8

7 Abdominal punctuation coarser and denser (fig. 44).: A (fig. 107).: S (fig.21). 5.0- 6.0 mm (FB: 2.6-2.8 mm) ................................................................... S. miwai BERNHAUER

- Abdominal punctuation less coarse, sparser (fig. 27).: A (fig. 108).: S (fig. 20). 5.0-6.0 mm (FB: 2.4-2.7 mm) ............................................................ S. mithracifer nov.sp.

8 Elytral spot smaller, not extending to the posterior margin of elytra, abdominal punctuation less coarse.: A (fig. 116).: S (e. g. fig. 16). 5,5- 6.5 mm. (FB: 2.4-2.7 mm) ............................................................................................. S. electrigemmeus nov.sp.

- Elytral spot larger, extending to the posterior margin of elytra, abdominal punctuation coarser.: A (fig. 19).: Unknown. 6.5 mm (FB: 2.6 mm) ..... S. electrigemmatus nov.sp.

9 Tarsal segment 4 simple.: A (figs 1-2, PUTHZ 2008).: no sclerotized S. 4.0- 5.0 mm (FB: 2.3-2.5 mm) .......................................................................... S. alienus SHARP Japan, China, Russia (Siberia, Primorje), Korea

- Tarsal segment 4 bilobed...................................................................................................10

10 Paraglossae oval (fig. 1, 2)................................................................................................11

- Paraglossae coniform (fig. 3, 4)........................................................................................18

11 Sternum 9 pointed apicolaterally (figs 86-88, 120, 121)...................................................12

- Sternum 9 serrate apically (fig. 85)...................................................................................15

12 Elytral spot larger, oval, in lateral half of elytra (fig. 31); punctures on tergite 7 as large as eye facets near dorsal eye margin. Three very close species which should be identified by dissecting the males.....................................................................................13

- Elytral spot smaller, round, in actual middle of elytra (fig. 35); punctures on tergite 7 smaller than eye facets near dorsal eye margins.: A (fig. 110).: S (fig. 112). 4.3- 5.0 mm (FB: 2.1-2.2 mm) ................................................................ S. shibataianus nov.sp.

13: A (fig. 117).: S (fig. 113). 4.0- 5.4 mm (FB 2.0- 2.2 mm)........ S. electristigma nov.sp.

-: A otherwise..................................................................................................................14

14: A (fig. 109).: S as in fig. 112). 5.0-6.0 mm (FB: 2.4-2.7 mm) ...... S. shibatai nov.sp.

-: A (fig. 111).: unknown. 4.6 mm (FB: 2.3 mm) ...................... S. shibataiellus nov.sp.

15 Abdominal punctuation extremely dense, interstices smaller than half diameter of punctures.: A (fig. 62, PUTHZ 1969).: S (fig. 22). 3.5-5.0 mm (FB: 1.9-2.4 mm). Known from Hainan. Records from Taiwan? .................................... S. virgula FAUVEL (?) - Abdominal punctuation less dense, interstices much larger than half diameter of punctures...........................................................................................................................16

16 Larger, punctuation on tergite 7 less coarse, punctures smaller than one eye facet near dorsal eye margin ..............................................................................................................17

- Smaller (FB: 2.1-2.4 mm), punctation on tergite 7 coarser, punctures larger than eye facets near dorsal eye margins.: A (fig. 97).: S (fig. 115). 3.8-5.3 mm ......................... ........................................................................................................... S. arisanus CAMERON

17 Elytra longer than broad, abdominal punctuation coarser and less dense.: A (fig. 118).: S (fig. 24). 5.5-7.2 mm (FB: 2.8-3.2 mm) .............................. S. stigmosus nov.sp.

- Elytra as long as broad, abdominal punctuation less coarse, denser.: A (fig. 119).: S (fig. 25.). 5.0- 6.5 mm (FB: 2.4-2.8 mm) ............................................. S. stigmifer nov.sp.

18 Punctation of tergite 7 coarser and very dense, interstices smaller than diameter of punctures, punctures at least as large as eye facets near dorsal eye margin......................19

- Abdominal punctuation denser, interstices on lateral half of tergite 4 on the average smaller than half diameter of punctures............................................................................22

19 Elytral spot longer, two thirds as long as one elytron or longer (fig. 41).: A (figs 66, 67), EC (fig 81, 82).: S (fig. 103). 5.2-7.9 mm (FB: 3.0- 3.4 mm).......... S. bilunatior nov.sp.

- Elytral spot shorter, one third as long as one elytron or shorter (0.26-0.45, ø 0.34).........20

20 Elytral spot mostly shorter (SpL: EL = 0.29-0.45, ø 0.33), not elevated from rest of elytral surface.: Trochanter simple, metatibiae straight.................................................21

- Elytral spot elevated from rest of elytral surface, longer (SpL: EL = 0.38).: Trochanter with a prominent tooth (fig. 96), metatibae curved, A (fig. 65), EC (fig. 79, 91).. 4 mm)......................................................................................... S. bigemmatus nov.sp.

21: Anterior portion of median lobe as strongly sclerotized anteriorly as posteriorly, less rounded, A (figs 58-63, 106), EC (figs 75-78).: S (fig. 105). 5.8-7.5 mm (FB: 2.9-3.3 mm)............................................................................................. S. bilunatus PUTHZ

-: Anterior portion of median lobe weakly sclerotized anteriorly, more rounded, A (fig. 64), EC (fig. 80, 90).: S (about as in fig. 105). 6.5-7.0 mm (FB: 3.1-3.4 mm)........... .......................................................................................................... S. bigemmosus nov.sp.

22 Punctation of pronotum preponderately distinctly delimited.: A (fig. 10, PUTHZ 1968). S (fig. 23). 4.0-5.0 mm (FB: 2.2-2.4)............................................. S. bicolon SHARP

- Punctation of pronotum preponderately confluent............................................................23

23 Abdominal punctuation denser, interstices on lateral half of tergite 4 on the average smaller than half diameter of punctures............................................................................24

- Abdominal punctuation less dense, interstices on lateral half of tergite 4 distinctly larger than half diameter of punctures, may become as large as punctures. A (fig. 69), EC (fig. 84, 93).: about as in fig. 105). 6.3-7.3 mm (FB: 3.2 mm)....... S. bistigmosus nov.sp.

24: EC (fig. 92).: S (fig. 104). 5.3-7.0 mm (FB: 2.9-3.1 mm) ........ S. bilunatoides nov.sp.

-: EC (fig. 83, 94).: S (as in fig.105). 5.8-6.8 mm (FB: 2.8-3.1 mm)........ S. biluminatus nov.sp.

25 Elytra as long as or longer than broad.: Sternite 9 triangularly pointed.: no sclerotized S. 4.0- 4.5 mm (FB: 2.2-2.3 mm) ............................................... S. changi PUTHZ (note: in some specimens the reddish spot can be obsolete)

- Elytra shorter than long.: Sternite 9 apicolaterally acute, A (fig. 69, PUTHZ 1969).: S (fig. 10). 4.8-6.0 mm (FB: 2.3-2.5 mm) ............................................... S. guttalis FAUVEL

Figures

Figs 1-10: Paraglossae (1-4), head (5-7) and spermatheca (8-10) of Stenus gestroi FAUVEL (1, 2, 5, Wulu; 8, Alishan Rd. 129), S. bilunatus PUTHZ (3, 4, near Litao), S. habropus PUTHZ (6), S. bilunatoides nov.sp. (7, PT), S. cephalo PUTHZ (9, Java, Tretes), S. guttalis FAUVEL (10, Tioman).