Erymus Bordoni, 2002

Zhou, Yu-Lingzi & Zhou, Hong-Zhang, 2014, Taxonomy of the genus Erymus Bordoni (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) in China with descriptions of two new species, Zootaxa 3814 (4), pp. 521-536 : 522-523

Genus Erymus Bordoni, 2002

Bordoni, 2002: 549 (species included: fas, javanicus, guillaumei, vexator , talangensis, gracilis , anomoius, hyatti, apateticus, schwendingeri, blasurus, pluvialis, jacobsoni, axiologus, ceramae, heumorphus, bruneianus); Bordoni, 2007: 68 (catalog).

Type species: Erymus vexator Bordoni, 2002: 558 , fixed by original designation.

The genus Erymus can be distinguished from all other genera within the tribe Xantholinini by the following characters: a) body subcylindrical, usually small in size (3–6 mm), rarely larger (ca. 8 mm); b) head glabrous, with sparsely-scattered and coarse punctures, some with microsculpture, lateral margins normally arcuate; c) frontal furrows often long and deep, ocular furrows usually indistinct; d) antennomere II normally longer than III, some subequal in length, III subspherical or elongate; e) labrum bilobed, with V-shaped anterior margin; f) penultimate segment of maxillary and labial palpi longest, dilated subapically, and last segment of maxillary and labial palpi obconical; g) gular sutures not fused together, separated by the shallowly excavated gular plate; h) neck nearly 1/3 of head width; i) pronotum normally with paired admedian and lateral rows of punctures; j) antesternal plate with a longitudinal medium furrow; k) superior line of hypomeron bending toward prosternum before anterior angle of pronotum, but not joining inferior line; l) protarsi not dilated, and only protibiae with subapical ctenidia; m) bulbus of aedeagus subovoid, anterior portion distinctly short or missing, parameres symmetrical, well-developed and distinctly long; n) female genital segments composed of a distinct rhomboidal sternite, and a pair of subtriangular sclerites ventrally (cf. Bordoni 2002, pp.68: fig. 83).

Based on the distributions of the Erymus species recorded in China ( Fig. 6 ), all Chinese species are clearly the Oriental faunal elements since their northernmost distribution borders do not expand either beyond the south boundary of Tibet Plateau, or into northern China in the monsoon region of the Eastern Asia. Of them, E. gracilis (Fauvel) is a widely distributed species, while all other Chinese species, as far as known, have relatively narrow distributions.

Key to the species of Erymus Bordoni

1 Body large, longer than 7 mm .......................................................... E. paramerum Bordoni

- Body small, shorter than 5 mm ........................................................................... 2

2 Admedian row of pronotum of 9–10 punctures.............................................. E. wufengensis sp. n.

- Admedian row of pronotum of 5–7 punctures............................................................... 3

3 Body color light brown; distance between punctures of head about the diameter of 5–6 punctures........... E. gilvus sp. n.

- Body color dark brown; distance between punctures of head less than the diameter of 5 punctures...................... 4

4 Parameres nearly straight and elongate...................................................... E. gracilis (Fauvel)

- Parameres arcuate and shorter............................................................................ 5

5 Anterior part of aedeagus strongly protruding................................................. E. sinicus Bordoni

- Anterior part of aedeagus slightly protruding................................................. E. dalianus Bordoni

Figures

FIGURE 6. Geographical distribution of species of the genus Erymus Bordoni in China. Erymus wufengensis sp. n. (♠); E. gilvus sp. n. (⋅); E. dalianus Bordoni (●); E. sinicus Bordoni (); E. paramerum Bordoni (∗); E. gracilis (Fauvel) (▲).