Scaphisoma Leach, 1815

Löbl, Ivan, 2023, On the Scaphidiinae (Coleoptera: Staphylinidae) of Java, Indonesia, Acta Musei Moraviae, Scientiae biologicae 108 (1 - 2), pp. 1-34 : 7-9

Scaphisoma Leach, 1815

Members of the genus may be easily distinguished from other Asian Scaphisomati by the short third antennomere, reduced elytral vestiture, and distinct submetacoxal lines. Scaphisoma is with over 800 species the species­richest genus of the subfamily. Its distribution is nearly world­wide ( LÖBL, 2018). The genus appears to be species­richer in Asia than in other areas, possibly due to the lack of adequate knowledge of its Afrotropical and Neotropical members.

Key to Javanese species of Scaphisoma

1 Elytron with shortened sutural stria, fine, irregular punctation, obliquely truncate apical margin and light apical fourth. Small species, body length below 1.5 mm. .......................................................................... S. grouvellei Achard

Elytral characters different. Body often longer. ............ 2

2 Pronotum uniformly ochraceous or yellowish. ......... .. 3

Pronotum ochraceous with dark basal pattern, or dark brown to blackish. ...... 5

3 Body length about 1.60 1.90 mm. Aedeagus with basal bulb expanded apically and overlapping apical process, parameres symmetrical. ........................... .. 4

Body length 2.05 2.10 mm. Aedeagus with basal bulb not expanded apically, parameres asymmetrical. ........... S. chujoi Löbl

4 Elytron with sutural stria parallel to suture between strongly diverging anterior section and apical half of sutural length. Male ventrite I lacking sexual characters. Apices of parameres expanded proximally in dorsal view. ...... .................................................................. S. binhanum (Pic)

Elytron with sutural stria converging from base to apex. Male ventrite I with two minute denticles. Apices of parameres not or hardly expanded proximally in dorsal view. ...................................................................... S. dohertyi Pic

5 Pronotum ochraceous with dark basomedian pattern. .......... 6

Pronotum unicolor, dark. .......... .. 8

6 Elytron on prevailing surface darker than pronotum, sutural stria of elytron strongly converging to suture from base to apex.. 7

Elytron on prevailing surface as light as pronotum, sutural stria of elytron weakly converging to suture.. S. bryanti sp. nov.

7 Dark pronotal patch well delimited, limited onto basal third of pronotal mid­length and notched. ........ S. testacemaculatum testacemaculatum (Pic) , male

Dark pronotal patch poorly delimited, extending over most of mesal part of pronotum, not notched. .. S. aspectum Löbl , male

8 Elytron with sutural stria extending laterad to form basal stria. ......... 9

Elytron with sutural stria starting near pronotal lobe, basal stria absent. 11

9 Pronotal punctation much finer than elytral punctation. Antennomere IV elongate, 3 to nearly 5 times as long as wide. ......... 10

Pronotal and elytral punctation similar. Antennomere IV very short, wider than long. S. neglectoides sp. nov.

10 Ventrite I with submetacoxal areas 0.03 mm long, about as long as tenth of shortest interval to apical margin of ventrite, submesocoxal lines parallel. ........ ............................................................................. S. planatoides sp. nov.

Ventrite I with submetacoxal areas 0.06 0.08 mm long, about as long as third of shortest interval to apical margin of ventrite; submesocoxal lines strongly convex. ............................................................................. S. drescheri sp. nov.

11 Elytra with discal punctation conspicuously coarse and forming oblique rows. Hypomeron with strigulate microsculpture... 12

Elytral punctation not in rows. Hypomeron lacking microsculpture.. .. 13

12 Punctation on centre of pronotum much finer than that near lateral margins. Internal sac of aedeagus lacking bunches of elongates spines. .............. ............................................................................. .. S. rouyeri Pic, 1916

Punctation on centre and along lateral margins of pronotum similar. Internal sac of aedeagus with bunches of elongate spines. S. multispinosum sp. nov.

13 Elytra with sutural striae strongly converging from base to apex. 14

Elytra with sutural striae entirely or to large part parallel. 17

14 Elytral disc with punctation inconspicuous, finer than that on adsutural area or on pronotum. Body about 1.25 1.35 mm long. .. S. jacobsoni Löbl

Elytral disc with punctation distinct, similar to, or coarser than that on adsutural area and on pronotum. ................. .. 15

15 Body about 1.25 1.35 mm long. Elytron with large light subbasal spot extending to elytral mid­length, and yellowish at apex. ....................................... ...... ........................................ S. oblongomaculatum Motschulsky

Body about 1.80 2.20 mm long. Elytron with small light subbasal spot not extending up to elytral mid­length, apex of elytron darkened. ........................ 16

16 Elytron with anterior margin of subapical spot emarginate. ................................ .............................. S. testaceomaculatum testaceomaculatum (Pic) , female

Elytron with anterior margin of subapical spot not emarginate. .......................... ............................................................................... S. aspectum Löbl , female

17 Elytron unicolor, or with indistinctly lightened apical area. .. 18

Elytron with distinct bicolorous patter. .................... .. 20

18 Metaventrite with apicomesal impression, strigulate microsculpture and antecoxal puncture rows. Aedeagus lacking flagellum. .. 19

Metaventrite with two apicomesal striae, lacking apicomesal impression, strigulate microsculpture, and antecoxal puncture rows. Aedeagus with flagellum extruded in repos. ...................................... .. S. caudatum Löbl

19 Body 1.40 1.85 mm long, dark brown to blackish. Aedeagus with parameres expanded apically, each bearing large lobe prominent apically. .......................... ............................................................ S. malaccanum (Pic)

Body 1.10 1.20 mm long, light reddish brown. Aedeagus with parameres narrowed apically, each bearing small lobe prominent basoventrally. ................ .......................................................................... S. javanum Löbl

20 Elytron dark brown to blackish with light subbasal spot and yellowish apical third. Aedeagus with parameres not expanded apically. ..................................... .................................................................... S. luteomaculatum Pic

Elytron dark reddish­brown with yellowish apical third. .......... 21

21 Punctation on elytral disc coarser than pronotal punctation. Antennomere IV more than twice as long as III, antennomere V about 1.3 times as long as antennomere IV and hardly longer than antennomere VI. Aedeagus with parameres expanded apicad. ..................... S. posticum sp. nov.

Punctation on elytral disc finer than pronotal punctation. Antennomere IV about 1.5 times as long as III, antennomere V nearly twice as long as antennomere IV and much shorter than antennomere VI. S. flavapex Achard