On the Domene species of China, with descriptions of four new species (Coleoptera, Staphylinidae)

Abstract Material of the paederine genus Domene Fauvel, 1873 from China is examined. Nine species were identified, four of them described previously, one unnamed (represented exclusively by females), and four are newly described: Domene cultrata sp. n. (Gansu, Hubei, Shaanxi); Domene cuspidata sp. n. (Gansu, Shaanxi, Sichuan); Domene chenae sp. n. (Guangxi); Domene reducta sp. n. (Sichuan). A lectotype is designated for Domene reitteri Koch, 1939; a neotype is designated for Domene chenpengi Li, 1990. Domene dersuuzalai Gusarov, 1992 is placed in synonymy with Domene chenpengi. Previous records of two Japanese species from China are most likely based on misidentifications and considered erroneous. Thus, the Domene fauna of China is currently composed of twelve described species. A key to the Domene species of China is provided. The distributions of eleven species are mapped.

In recent years we obtained numerous Domene specimens from several public and private collections. Nine species were identified, four of which are described for the first time.

Material and methods
The examined material is deposited in the following public and private collections: The genitalia and other dissected parts were mounted on plastic slides and attached to the same pin as the respective specimens. Photographs were taken with a Canon EOS 7D camera with a MP-E 65 mm macro lens or with a Canon G9 camera mounted on an Olympus CX31 microscope. The map is created using MapCreator 2.0 (primap) software.
The following abbreviations are used in the text, with all measurements in millimeters: Total length ( The type labels are cited in the original spelling; different labels are separated by slashes.

Results
Thirteen Domene species, ten of them exclusive and one of them unnamed, are known from China (including Taiwan). Four species are described for the first time, a new synonymy is proposed and two species are deleted from the list of Chinese Domene species.
Based on the male sexual characters, mainly the shape and chaetotaxy of sternite VIII and the morphology of the aedeagus, as well as on external characters such as the punctation and sculpture of the head, pronotum and elytra, the Chinese representatives of Domene are attributed to five different species groups.
The D. scabripennis group: see Assing and Feldmann (2014). Note that the placement of D. firmicornis in this group is doubtful. Neither the male nor the female sexual characters suggest closer phylogenetic affiliations to any of the other species known from China.
The D. malaisei group comprises four species (D. malaisei, D. cultrata, D. cuspidata, D. reducta) distributed in the midwest and southwest of China. They share the following differential characters: large body size (length of forebody 4.70-5.50 mm); head and pronotum with moderately coarse and dense punctation; pronotum relatively large and oblong; protarsomeres I-IV weakly dilated in both sexes; elytra with moderately coarse, not coriaceous and irregular macropunctation, with additional micropunctation, without distinct longitudinal elevations and without pronounced impressions; male sternite VII with modified short, stout, black setae; sternite VIII with shallow median impression, this impression with strongly modified, stout black setae, on either side of the deep and almost V-shaped posterior excision with a dense cluster of black setae; ventral process of aedeagus (in lateral view) not conspicuously slender, rather stout.
The D. reitteri group includes two species (D. reitteri, D. chenae) distributed in the east and south of China and is distinguished by the following character combination: moderately large body size (length of forebody 4.16-4.73 mm); head and pronotum with fine and dense punctation; pronotum large and moderately oblong; protarsomeres I-IV weakly dilated in both sexes; elytra without rough surface, with fine, dense and uniform punctation; male sternite VII with moderately to strongly modified short, stout, black setae; sternite VIII with shallow median impression, this impression with strongly modified stout black setae, on either side of the moderately deep and Ushaped posterior excision without cluster of setae; ventral process of aedeagus (in lateral view) relatively stout.
D. chenpengi and D. procera belong to two different species groups which comprise additional species from Japan. Domene chenpengi is closely related to D. curtipennis and allied species, D. procera is closely related to D. crassicornis and allied species. A detailed characterization of these species groups requires a revision of the Domene fauna of Japan.

Domene (Macromene) chenpengi Li et al., 1990
Figs 1, 2A, 3 description of D. chenpengi, which fails to provide any illustration whatsoever, is in agreement with examined material previously identified as D. dersuuzalai from the Russian Far East and China, particularly regarding the habitus and the characteristic shape of the male sternite VIII with its shallow posterior excision. Moreover, the type locality of D. chenpengi accords with the known distribution of D. dersuuzalai. In the interest of stability of nomenclature, a neotype designation is deemed necessary to stabilize the present interpretation of D. chenpengi and the synonymy with D. dersuuzalai. To this end, a male from the Dongling mountains in Beijing, a locality reasonably close to the type locality, is designated as the neotype. Based on the detailed descrip- tion of D. dersuuzalai (Gusarov 1992), the species is doubtlessly conspecific with the neotype of D. chenpengi; hence the synonymy proposed above.
Head orbicular, widest behind eyes; punctation (Fig. 3A) fine and very dense. All antennomeres longer than broad; antennomeres IV-X of equal length; antennomere I 1.9 times, II 1.2 times, III 1.3 times, XI 1.3 times as long as IV. Maxillary palpus slender, preapical joint about 2.5 times as long as broad.
Pronotum about as broad as head, widest in anterior third; lateral margins slightly convex in dorsal view; punctation ( Fig. 3B) very fine with interstices forming narrow, longitudinal ridges.
Elytra without distinct longitudinal ridges; disc often more or less impressed; suture elevated in posterior three-fourths; macropunctation coarse, more or less dense and irregular on disc, interstices with shallow and irregular micropunctation; in lateral and posterior portions with distinctly finer and denser punctation. Hind wings present. Protarsomeres I-IV moderately dilated.
Abdomen with fine and very dense punctation on tergites III-VIII; interstices with microreticulation; tergite VIII more or less obtusely triangularly produced posteriorly (Fig. 3C); posterior margin of tergite VII with palisade fringe.
Male. Sternites III-VI unmodified; sternite VII ( Fig. 3F) distinctly transverse, with shallow postero-median impression, this impression with a few modified short  Comparative notes. The similar external morphology, the similar chaetotaxy and shape of the male sternites VII and VIII, and especially the similar shape of the ventral process of the aedeagus suggest that D. chenpengi is closely allied to D. curtipennis from Japan. For illustrations of D. curtipennis see Gusarov (1992: figure 4). Besides its conspicuous male sexual characters, D. chenpengi is distinguished from the Chinese species of the D. malaisei and D. scabripennis groups and from D. procera by its smaller size alone, and from species of the D. reitteri group by its coarser and less densely punctate the elytra.
Distribution and natural history. The currently known distribution ranges from the Russian Far East and Northern China (Beijing, Jilin) to South Korea. The specimens were partly sifted from leaf litter in mixed forest habitats or found under bark and rocks. The elevations range from 100 up to 1400 m.

Domene (Macromene) crassicornis (Sharp, 1874)
Lathrobium crassicornis Sharp, 1874: 59. Li et al. (1990) from Jilin, the only record of this species from China. This record is evidently based on a misidentification and probably refers to D. procera. Based on available evidence, the distribution of D. crassicornis is restricted to Japan and consequently does not include China. All revised material from the Russian Far East belongs to D. procera.
Comment. The sole record of D. curtipennis from China is that by Li (1992) from Liaoning. It is almost certainly based on a misidentification. Based on available evidence, the distribution of D. curtipennis is restricted to Japan. All the examined material from the Russian Far East, South Korea and China belongs to D. chenpengi, suggesting that D. curtipennis does not occur in China.  Habitus as in Fig. 5. Body black; legs with blackish brown profemora and brown protibiae, basal halves of metafemora light brown, distal halves gradually infuscate; antennae dark brown to brown.
Pronotum nearly as broad as head, widest in the middle; lateral margins convex in dorsal view; punctation (Fig. 6B) somewhat coarser than that of head; midline with rudiment of fine glossy line.
Elytra without distinct longitudinal ridges; disc more or less weakly impressed; suture elevated in posterior three-fourths; macropunctation coarse, irregular, partly confluent, and partly somewhat seriate; interstices with shallow and irregular micropunctation. Hind wings fully developed. Protarsomeres I-IV moderately dilated.
Abdomen with fine and dense punctation on tergites III-VI; tergite VIII with dense pubescence, posterior margin of tergite VIII broadly and weakly convex (Fig. 6C); interstices with distinct microreticulation; posterior margin of tergite VII with palisade fringe.
Male. Sternites III-VI unmodified; sternite VII ( Fig. 6F) distinctly transverse, with very shallow median impression posteriorly, this impression with sparse modified black setae, posterior margin broadly concave; sternite VIII ( Fig. 6G) with shallow median impression posteriorly, this impression with stout black setae, posterior excision deep, almost V-shaped, on either side of the posterior excision with dense cluster of dark setae; aedeagus as in Figs 6H-J, ventral process evenly curved and apically acute in lateral view; dorsal plate long, apical portion distinctly sclerotized and apically acute in lateral view, basal portion short.
Comparative notes. The similar chaetotaxy and shape of the male sternite VIII and the similar shape of the ventral process of the aedeagus suggest that D. malaisei is closely allied to D. reducta. Domene malaisei is readily distinguished from other species of the group by on average darker coloration, smaller body size, the deeper posterior excision of the male sternite VIII, the evenly curved ventral process of the aedeagus and by the shape of the sclerotized structure in the female genital segments.
Distribution and natural history. The currently known distribution is confined to the type locality Kambaiti in northeastern Myanmar at the border with Yunnan, and two localities in western Yunnan (Fig. 1). The examined non-type specimens were sifted from forest leaf litter at altitudes of 2000-2500 m.  Comment. The original description of D. reitteri is based on an unspecified number of syntypes from "Tienmuschan (nordwestliches [sic] China) ex coll. E. Reitter" (Koch 1939). Five syntypes, one male, three females and one unsexed specimen, were located in the Koch collection at the Naturhistorisches Museum Basel. The male syntype is designated as the lectotype.  Habitus as in Figs 7A, 8A, 8D. Body blackish brown; legs with dark brown profemora and protibiae, basal halves of metafemora light brown, distal halves gradually infuscate; antennae brown to light brown.
Head orbicular, broadest across eyes; punctation (Fig. 9A) moderately coarse, weakly umbilicate, and very dense, interstices forming very narrow ridges. All antennomeres longer than broad; antennomeres IV-X of equal length; antennomere I 1.6 times, II 1.1 times, III 1.3 times, XI 1.3 times as long as IV. Maxillary palpus very slender, preapical joint 2.7-3.2 times as long as broad. Pronotum slightly narrower than head, widest in the middle; lateral margins convex in dorsal view; punctation (Fig. 9B) somewhat coarser than that of head; midline with rudiment of a fine glossy line.
Elytra without distinct longitudinal ridges; suture weakly elevated; punctation very fine, dense and uniform; hind wings reduced. Protarsomeres I-IV dilated in both sexes.
Abdomen with punctation fine and dense on tergites III-VI, finer and somewhat sparser on tergite VIII, posterior margin of tergite VIII weakly convex in the middle (Fig. 9C); interstices with shallow microreticulation; posterior margin of tergite VII with palisade fringe.
Male. Sternites III-VI unmodified; sternite VII (Figs 8B, 9F) distinctly transverse, with median impression of triangular shape posteriorly, this impression with numerous distinctly modified, short and stout black setae; posterior margin distinctly concave in the middle; sternite VIII (Figs 8B, 9G) transverse, with pronounced and symmetric impression posteriorly, this impression with distinctly modified short and stout black setae, posterior excision small and U-shaped; aedeagus as in Figs 8C, 9H-J, ventral process stout and apically acute; dorsal plate with large and lamellate apical portion, and with short, thin basal portion; internal sac with membranous structures.
Comparative notes. The fine, dense and uniform punctation of the elytra, and the similar shape and chaetotaxy of the male sternite VII and sternite VIII suggest that D. reitteri is most closely allied to D. chenae. It is distinguished from D. chenae by the finer punctation of the head and pronotum, the numerous distinctly modified, short and stout black setae on the male sternite VII, the stouter ventral process of the aedeagus and by the shape of the sclerotized structure in the female genital segments.
Distribution and natural history. The distribution is confined to several localities in the Tianmu Shan range in the northwest of Zhejiang. The specimens were sifted from leaf litter in broad-leaved and primary mixed forests at altitudes of 300-1500 m. Etymology. The species is named after Yan Chen, who collected some of the type specimens.
Description. Measurements (in mm) and ratios: BL 7. Habitus as in Fig. 7B. Body black with distinctly paler abdominal apex; legs with blackish brown profemora and dark brown protibiae, basal halves of metafemora light brown, distal halves gradually infuscate; antennae brown to light brown.
Pronotum narrower than head, widest in the middle; lateral margins weakly convex in dorsal view; punctation (Fig. 10B) similar to that of head; midline with rudiment of a fine glossy line.
Elytra without distinct longitudinal ridges; suture elevated in posterior two thirds; punctation fine, dense and uniform; interstices without micropunctation. Hind wings probably present. Protarsomeres I-IV moderately dilated.
Abdomen with fine and dense punctation on tergites III-VIII; posterior margin of tergite VIII broadly and weakly convex (Fig. 10C); interstices with shallow microreticulation; posterior margin of tergite VII with palisade fringe.
Male. Sternites III-VI unmodified; sternite VII ( Fig. 10F) distinctly transverse, with median impression of triangular shape posteriorly, this impression with moderately modified dark setae, posterior margin broadly concave in the middle; sternite VIII ( Fig. 10G) transverse, with shallow median impression posteriorly, this impression with distinctly modified stout and black setae, posterior excision small and U-shaped; aedeagus as in Figs 10H-J, ventral process more slender and curved, apically acute; dorsal plate with distinctly sclerotized apical portion, basal portion short.
Comparative notes. The fine, dense and uniform punctation of the elytra, and the similar shape and chaetotaxy of the male sternite VII and sternite VIII suggest that D. chenae is allied to D. reitteri. The species is distinguished from D. reitteri by the coarser punctation of the head and pronotum, the somewhat shorter elytra, the moderately modified dark setae of the male sternite VII, the differently shaped ventral process of the aedeagus and the more distinctly sclerotized structure in the female genital segments.
Distribution and natural history. The type locality is situated in Anjiangping to the northwest of Guilin, northern Guangxi (Fig. 1). The specimens were sifted from leaf litter and grass in broad-leaved forests at an altitude of 1200 m. Etymology. The specific epithet is an adjective derived from the Latin noun culter (knife) and alludes to the shape of the ventral process of the aedeagus.
Description. Measurements (in mm) and ratios: BL 8. Habitus as in Fig. 11A. Body dark brown; legs brownish yellow, with brown profemora and protibiae; antennae brown to light brown. Head orbicular, widest behind eyes; punctation (Fig. 12A) coarse, umbilicate and dense, interstices forming very narrow ridges. All antennomeres longer than broad; antennomeres IV-X of equal length; antennomeres I 1.6 times, II 0.9 times, III 1.3 times, XI 1.4 times as long as IV. Maxillary palpus very slender, preapical joint 2.8-3.0 times as long as broad.
Pronotum about as wide as head, widest in the middle; lateral margins convex in dorsal view; punctation (Fig. 12B) similar to that of head; midline with rudiment of a fine glossy line.
Elytra without distinct longitudinal ridges; suture elevated in posterior two thirds; macropunctation coarse, irregular, partly confluent, and partly somewhat seriate; in- terstices rugose, rendering elytra matt, with irregular and mostly barely visible micropunctation (visible in posterior part of elytra). Hind wings fully developed. Protarsomeres I-IV distinctly dilated.
Abdomen with fine and dense punctation on tergites III-VIII; posterior margin of tergite VIII broadly convex (Fig. 12C); interstices with distinct microreticulation; posterior margin of tergite VII with palisade fringe.
Male. Sternites III-VI unmodified; sternite VII ( Fig. 12F) distinctly transverse, with shallow median impression posteriorly, this impression with sparse, strongly modified, short and stout black setae, posterior margin broadly concave; sternite VIII ( Fig. 12G) with shallow median impression, this impression with distinctly modified stout black setae, posterior excision moderately deep and V-shaped, on either side of the posterior excision with dense cluster of dark setae; aedeagus as in Figs 12H-J, ventral process nearly straight and apically acute; dorsal plate with long, large and distinctly sclerotized apical portion, basal portion short and lamellate; internal sac with small sclerotized spines and with distinct membranous structures.
Intraspecific variation. Domene cultrata is subject to rather pronounced intraspecific variation of size, body proportions and coloration of the legs.
Comparative notes. Based on the similar chaetotaxy and shape of the male sternite VIII, and the shape of the ventral process of the aedeagus, D. cultrata belongs to the D. malaisei species group and is allied to D. cuspidata. It can be distinguished from other species of the group by the distinctly coarser macropunctation of the elytra, the differently shaped ventral process of the aedeagus, and the slender sclerotized structure in the female genital segments, from D. malaisei and D. reducta also by the shallower impression and the less deep posterior excision of the male sternite VIII.
Description. Measurements (in mm) and ratios: BL 8.  External characters (Fig. 11B) as in D. cultrata, distinguished only by the distinctly less coarse macropunctation and less rugose interstices of the elytra rendering the elytra more shiny in D. cuspidata, and by the primary and secondary sexual characters: Male. Sternites III-VI unmodified; sternite VII ( Fig. 13F) distinctly transverse, with shallow postero-median impression, this impression with sparse strongly modified, short and stout black setae, posterior margin concave in the middle; sternite VIII ( Fig. 13G) with extensive median impression, this impression with distinctly modified stout black setae, posterior excision less deep, V-shaped, on either side of the posterior excision with a dense cluster of dark setae; aedeagus as in Figs 13H-J, ventral process distinctly sclerotized, with slender and very acute apical portion; dorsal plate with long, large and distinctly sclerotized apical portion, basal portion short; internal sac with membranous structures.
Comparative notes. Based particularly on the similar chaetotaxy and shape of the male sternite VIII and the shape of the ventral process of the aedeagus, D. cuspidata belongs to the D. malaisei species group and is closely allied to D. cultrata. It is distinguished from other species of the group by the apically more acute ventral process of the aedeagus and by the large, moderately sclerotized structure in the female genital segments, from D. malaisei and D. reducta also by the shallower impression and less deep posterior excision of the male sternite VIII.
Distribution and natural history. The species was recorded from the Qinling Shan and Dalou Shan (Fig. 1). The specimens were sifted from forest leaf litter and a loamy meadow with tall herbaceous vegetation at altitudes of 1300-1850 m. Six paratypes found in July are teneral. Habitus as in Fig. 11C. Body dark brown; legs light brown with darker profemora and protibiae; antennae brown to light brown.
Pronotum slightly narrower than head, widest in the middle; lateral margins convex in dorsal view; punctation (Fig. 14B) somewhat coarser than that of head; midline with rudiment of a fine glossy line.
Abdomen with fine and dense punctation on tergites III-VIII; posterior margin of tergite VIII broadly and weakly convex (Fig. 14C); interstices with shallow microreticulation; posterior margin of tergite VII with palisade fringe.
Male. Sternites III-VI unmodified; sternite VII ( Fig. 14F) distinctly transverse, with median impression of triangular shape posteriorly, this impression with strongly modified, short and stout black setae, posterior margin weakly concave in the middle; sternite VIII ( Fig. 14G) with shallow and extensive median impression, this impression with stout black setae, posterior excision moderately deep and V-shaped, on either side of the posterior excision with a dense cluster of dark setae; aedeagus as in Figs 14H-J, ventral process long, slender, evenly curved and apically acute; dorsal plate with long and distinctly sclerotized apical portion, basal portion long and lamellate. Female. Posterior margin of sternite VIII (Fig. 14D) broadly convex; genital segments with a small symmetric, weakly sclerotized structure (Fig. 14E).
Comparative notes. Based particularly on the similar chaetotaxy and shape of the male sternite VIII, and the shape of the ventral process of the aedeagus, D. reducta belongs to the D. malaisei species group and is closely related to D. malaisei. Domene reducta is distinguished from other species of the group by on average larger body size (especially from D. malaisei), the shape of the impression on the male sternite VIII, the long, slender, evenly curved ventral process of the aedeagus and by the symmetric, small and moderately sclerotized structure in the female genital segments.
Distribution and natural history. The species is known from the Qingcheng Shan and Hengduan Shan, central Sichuan (Fig. 1). The specimens were sifted from leaf litter and soil in evergreen broad-leaved forests at altitudes of 1400-1900 m. Nine paratypes found in July are teneral.
Comment. The above brachypterous females undoubtedly represent an undescribed species distinguished from the other species known from China by the conspicuously large head and the distinctly impressed sutural portion of the elytra, from most species also by the short and narrow elytra and by the absence of a palisade fringe at the posterior margin of the male tergite VII.

Key to the Domene species of China
Because of some variability in size, body proportions, coloration, punctation and sculpture in most species, a positive identification (especially of the species of the malaisei group) requires the examination of the genitalia.