Key to the Kalimantan species of Scaphisoma

1 Elytra conspicuously microsculptured, dull. ................................ S. apparatum sp. nov.

– Elytra glabrous, not microsculptured. ............................................................................ 2

2 Elytra with sutural striae bent along base to form basal striae. ...................................... 3

– Elytra without basal striae. ............................................................................................. 4

3 Antennomere V much longer than IV. Lateral pronotal carinae visible in dorsal view. ... ...................................................................................................... S. ruficolor (Pic, 1916)

– Antennomere V as long as IV. Lateral pronotal carinae not visible in dorsal view. ......... .............................................................................................................. S. pici Löbl, 1979

4 Elytral disc with conspicuously, oblique puncture rows. ............................................... 5

– Elytral disc with punctation irregular, not arranged in rows. ......................................... 6

5 Puncture rows not shortened on inflexed lateral parts of elytral disc and extended to, or almost to apical fifth of elytra. ........................................................ S. rouyeri Pic, 1916

– Puncture rows shortened on inflexed lateral parts of elytral disc and not extended onto apical third of elytral disc. .......................................................... S. punctatum Pic, 1915

6 Sutural striae of elytra starting posteriad to tip of scutellum. ........................................ 7

– Sutural striae of elytra starting at or anteriad to tip of scutellum. .................................. 8

7 Pronotum and elytra concolor. Median part of metaventrite lacking microsculpture. Parameres not overlapping. ................................................................ S. borneense Pic, 1916

– Pronotum lighter than elytra. Median part of metaventrite microsculptured. Parameres overlapping. ......................................................................................... S. tarsale sp. nov.

8 Apical third to half of elytron appearing impunctate, basal half of elytra coarsely punctate. ............................................................................................ S. rufescens (Pic, 1920)

– Elytral punctation distinct on entire discal surface. ....................................................... 9

9 Elytra with sutural striae conspicuously strongly converging apically, angulate in anterior section. ..................................................................................................................... 10

– Elytra with sutural striae weekly converging apically or parallel, not angulate. ......... 11

10 Punctation on adsutural areas of elytra much coarser than middle of elytral disc. Combined basal width of adsutural area 0.32 mm. Elytra with subapical and discal areas lighter than remaining surface. ..................................... S. lineatopunctatum (Pic, 1916)

– Punctation on adsusural areas similar to that on elytral disc. Combined basal width of adsutural areas about 0.25 mm. Apex of elytra lighter than remaining elytral surface. .... ............................................................................................... S. mindanaosum Pic, 1926

11 Elytral punctation conspicuously dense, puncture diameters on basal halves of elytra about twice broader than intervals. Ventrite 1 with submetacoxal areas about as long as half of intervals to apical margin. ......................................... S. punctatipenne Pic, 1916

– Elytral punctation sparse, puncture diameters narrower than puncture intervals. Ventrite 1 with submetacoxal areas shorter than half width of intervals to apical margin. ....... 12

12 Body 1.90 mm long. Pronotum and elytra light reddish brown, elytra lacking spots. Basomedian part of ventrite 1 with coarse punctures. ............. S. submaculatum Pic, 1920

– Body 1.15–1.35 mm long. Pronotum and elytra very dark, blackish-brown to black, each elytron with reddish humeral spot and lighter apical area. Entire ventrite 1 very finely punctate. ........................................................ S. obliquemaculatum Motschulsky, 1863