Tetrabothrus species

Assing, Volker, 2015, On the Tetrabothrus fauna of China (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Linzer biologische Beiträge 47 (1), pp. 127-143 : 129

Key to the Tetrabothrus species of China

C o m m e n t: For a key to the Tetrabothrus species of Taiwan see PACE (2010). Tetrabothrus bicolor CAMERON, 1939 from Burma is readily distinguished from all the species keyed below by its coloration alone (forebody black; abdomen red; legs blackish- brown; antennae black).

1. Elytra conspicuously short, approximately 0.55 times as long as pronotum ( Fig. 16 ). Hind wings and palisade fringe at the posterior margin of the abdominal tergite VII reduced ( Fig. 20 ). Antenna 1.7 mm long ( Fig. 19 ). Abdomen broader than elytra. Median lobe of aedeagus as in Figs 21-22 . Paramere with long and slender apical lobe ( Fig. 23 ). Yunnan ( Map 1 ) ...................................................................... brevalatus nov.sp.

- Elytra longer, at least approximately 0.85 times as long as pronotum. Hind wings and palisade fringe at the posterior margin of the abdominal tergite VII fully developed. Antenna shorter. Abdomen narrower than elytra. Sexual characters different...................2

2. Forebody distinctly bicoloured: pronotum pale-reddish, strongly contrasting with the blackish posterior portion of the head and the blackish elytra. Head strongly transverse,> 1.3 times as broad as long. Eyes much longer than distance from posterior margin of eye to posterior constriction of head ( Fig. 24 ). Abdomen broader, with more transverse segments ( Fig. 26 ). Tergite VIII and sternite VIII strongly transverse ( Figs 27-28 ). Northern Sichuan ( Map 1 )....................................................................... rubricollis nov.sp.

- Forebody not distinctly bicoloured, more or less uniformly reddish to dark-brown. Head less transverse, <1.3 times as broad as long. Eyes shorter than distance from posterior margin of eye to posterior constriction of head. Abdomen more slender and with less transverse segments. Tergite VIII and sternite VIII less transverse.....................3

3. Legs pale-yellowish, mostly with the apices of the femora weakly to distinctly infuscate..............................................................................................................................4

- Legs reddish-brown to brown, with the bases of the femora paler at most.........................5

4. Apices of the femora very narrowly and indistinctly infuscate at most. Anterior angles of pronotum visible in dorsal view. Median lobe of aedeagus smaller, 0.45 mm long at most, and with short, strongly angled ventral process ( Figs 15-16 ). Paramere smaller and with shorter apical lobe ( Fig. 17 ). Western Yunnan ( Map 1 ) ............... inflexus nov.sp.

- Apices of the femora broadly and distinctly infuscate. Anterior angles of pronotum not visible in dorsal view. Median lobe of aedeagus larger, 0.5 mm long, and with smoothly curved ventral process. Paramere larger and with longer apical lobe ( Fig. 6 ). Yunnan, North Sichuan ( Map 1 ) ..................................................................... cavus nov.sp.

5. Basal half to two-thirds of femora yellowish. Head with obtusely marked posterior angles ( Fig. 30 ). Pronotum less convex and more transverse, 1.13 times as broad as long ( Fig. 29 ). Apical portion of abdomen moderately tapering ( Fig. 32 ). Median lobe of aedeagus larger, 0.57 mm long and shaped as in PACE (2012: figures 21-22). Paramere> 0.6 mm long. Border region between Shaanxi, Chongqing, and Hubei ( Map 1 ). ....................................................................................................... chinensis PACE

- Femoral bases only narrowly and indistincly paler than remainder of femora and tibiae. Posterior angles of head obsolete. Pronotum more convex in cross section and less transverse. Apical portion of abdomen strongly tapering ( ASSING 2009: figures 16, 32). Median lobe of aedeagus 0.5 mm long and shaped as in ASSING (2009: figures 19-20). Paramere 0.5 mm long. Northwestern Yunnan ( Map 1 )................................. puetzi ASSING

Figures

Map 1: Distributions of Tetrabothrus species in China: T. puetzi (open triangle); T. inflexus (open circles); T. brevalatus (open star); T. cavus (filled circles); T. rubricollis (open diamond); T. chinensis (filled triangle).

Figs 12-17: Tetrabothrus inflexus nov.sp.: forebody (12); antenna (13); abdomen (14); median lobe of aedeagus in lateral and in ventral view (15-16); paramere (17). Scale bars: 12, 14: 1.0 mm; 13: 0.5 mm; 15-17: 0.2 mm.

Figs 18-23: Tetrabothrus brevalatus nov.sp.: forebody (18); antenna (19); abdomen (20); median lobe of aedeagus in lateral and in ventral view (21-22); paramere (23). Scale bars: 18, 20: 1.0 mm; 19: 0.5 mm; 21-23: 0.2 mm.

Figs 24-28: Tetrabothrus rubricollis nov.sp.: forebody (24); antenna (25); abdomen (26); female tergite VIII (27); female sternite VIII (28). Scale bars: 24, 26: 1.0 mm; 25, 27-28: 0.5 mm.

Figs 1-8: Tetrabothrus cavus nov.sp. from Yunnan (1-7) and Shaanxi (8): forebody (1); antenna (2); abdomen (3); male tergite VIII (4); male sternite VIII (5); paramere (6); female sternite VIII (7- 8). Scale bars: 1, 3: 1.0 mm; 2, 4-5, 7-8: 0.5 mm; 6: 0.2 mm.

Figs 29-32: Tetrabothrus chinensis PACE (holotype): forebody (29); head (30); antenna (31); abdomen (32). Scale bars: 29-30, 32: 1.0 mm; 31: 0.5 mm.