Stenus guttalis FAUVEL 1895

Stenus guttalis FAUVEL 1895 View in CoL ( Fig. 10 View Figs 1-10 )

Stenus guttalis FAUVEL 1895: 212 View in CoL ; 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 View in CoL

- 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 View in CoL

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 View in CoL

- 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 View in CoL

- 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 View in CoL 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 View in CoL 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 View in CoL 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 View in CoL 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 View in CoL nov.sp.

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

-: A (fig. 111).: unknown. 4.6 mm (FB: 2.3 mm) ...................... S. shibataiellus View in CoL 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 View in CoL (?) - 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 View in CoL

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 View in CoL 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 View in CoL 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 View in CoL 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 View in CoL 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 View in CoL

-: 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 View in CoL 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 View in CoL

- 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 View in CoL nov.sp.

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

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