Lobrathium MULSANT & REY, 1878

Assing, Volker, 2010, On the Lathrobiina of Taiwan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 60 (2), pp. 301-361 : 323-324

Genus Lobrathium MULSANT & REY ,, 1878

Lobrathium is represented in Taiwan by two species groups, one with seven species of the subgenus Lobrathium and one of uncertain subgeneric affiliations comprising at least approximately twenty endemic micropterous species. The latter is established below.

Only one of the seven species of the subgenus Lobrathium , L. sibynium , was described previously (from Sichuan); the remainder is described below. Six of the seven species have a more or less distinct reddish spot near the posterior margin of the elytra, a male sternite VII without peg-setae, a more or less strongly bilobed or undivided ventral process of the aedeagus, one, L. nigripenne , has uniformly blackish elytra, a male sternite VII with peg-setae, and an undivided, not conspicuously slender ventral process of the aedeagus, suggesting that these species may not represent a monophylum. Five species have long elytra and long hind wings and are probably capable of flight. One species, L. bilobatum , is wing di- or polymorphic and one, L. pedes , is micropterous.

The second complex of species with uncertain subgeneric affiliations, hereafter referred to as the L. stimulans group, includes only one previously described species ( L. taiwanense )). Twelve species are newly described; seven additional species are represented by females only and consequently not named. Remarkably, ten species (six named and four unnamed) lack the submarginal line of the elytra, one of the key characters for the identification of the genus distinguishing from lathrobiine genera such as Lathrobium and Domene . However, the absence of this submarginal line is most likely a secondary reduction, as can be inferred from the similar external and sexual characters, particularly the bilobed ventral process of the aedeagus, quite evidently a derived condition in the genus, as well as from the fact that one of the unnamed species (sp. 3) has a submarginal line of distinctly reduced length, apparently a transitional condition.

The species of the L. stimulans group are characterised by moderately large to large body size, a relatively large head, a compact pronotum, more or less reduced length of the elytra and the hind wings, the reduced palisade fringe at the posterior margin of the abdominal tergite VII, a characteristic bilobed aedeagus, which may be secondarily fused apically ( L. coalitum , see Figs 239-240 ), an anteriorly (sometimes very narrowly) divided female tergite IX (e.g., Figs 218 , 227 , 234, 243 ) (undivided in Taiwanese species of the subgenus Lobrathium ), and often an apically conspicuously acute female tergite X (e.g., Figs 152 , 161 , 170 , 233 ). They may represent a distinct subgenus, but this can be clarified only based on a comprehensive revision of all Eastern Palaearctic Lobrathium species.

Figures

Figs 234-243: Lobrathium kuanicum sp. n. (234) and L. coalitum sp. n. (235-243): female tergites IX-X (234, 243); habitus (235); forebody (236); male sternite VIII (237); aedeagus in lateral and in ventral view (238-239); apex of aedeagus in ventral view (240); female tergite VIII (241); female sternite VIII (242). Scale bars: 235-236: 1.0 mm; 234, 237-243: 0.5 mm.

Figs 211-218: Lobrathium bidigitatum sp. n.: habitus (211); forebody (212); male sternite VIII (213); aedeagus in lateral and in ventral view (214-215); female tergite VIII (216); female sternite VIII (217); female tergites IX-X (218). Scale bars: 211-212: 1.0 mm; 213-218: 0.5 mm.

Figs 219-227: Lobrathium spoliatum sp. n.: habitus (219); forebody (220); antenna (221); male sternite VIII (222); aedeagus in lateral and in ventral view (223-224); female tergite VIII (225); female sternite VIII (226); female tergites IX-X (227). Scale bars: 219-220: 1.0 mm; 221-227: 0.5 mm.

Figs 145-153: Lobrathium stimulans sp. n.: habitus (145); forebody (146); antenna (147); male sternite VII (148); male sternite VIII (149); aedeagus in lateral and in ventral view (150-151); female tergite VIII (152); female sternite VIII (153). Scale bars: 145-147: 1.0 mm; 148-153: 0.5 mm.

Figs 154-163: Lobrathium stimulans sp. n. (154) and L. sororium sp. n. (155-163): male tergite VIII (154); habitus (155); forebody (156); male sternite VII (157); male sternite VIII (158); aedeagus in lateral and in ventral view (159-160); female tergite VIII (161); female sternite VIII (162); apices of female tergites IX and X (163). Scale bars: 155-156: 1.0 mm; 154, 157-163: 0.5 mm.

Figs 164-171: Lobrathium duplehamatum sp. n.: habitus (164); forebody (165); antenna (166); male sternite VIII (167); aedeagus in lateral and in ventral view (168-169); female tergite VIII (170); female sternite VIII (171). Scale bars: 164-166: 1.0 mm; 167-171: 0.5 mm.

Figs 228-233: Lobrathium kuanicum sp. n.: habitus (228); forebody (229); male sternite VIII (230); aedeagus in lateral and in ventral view (231-232); female tergite VIII (233). Scale bars: 228-229: 1.0 mm; 230-233: 0.5 mm.