Further studies on the Pselaphodes complex of genera from China (Coleoptera, Staphylinidae, Pselaphinae)

Abstract New data on the Pselaphodes complex of genera (Pselaphitae: Tyrini) from China is presented. The generic limits of Labomimus Sharp and Pselaphodes Westwood are discussed and expanded. A revised key to the genera of the Pselaphodes complex is provided. New geographic evidence suggests that previously believed wide-spread species Pselaphodes tianmuensis Yin, Li & Zhao contains a number of related species, resulting in a division of the species to nine separate taxa. Fourteen new species belonging to three genera are diagnosed, described and illustrated: Dayao emeiensis Yin & Li, sp. n. (Sichuan), Labomimus fimbriatus Yin & Hlaváč, sp. n. (Yunnan), Labomimus jizuensis Yin & Hlaváč, sp. n. (Yunnan), Labomimus simplicipalpus Yin & Hlaváč, sp. n. (Sichuan), Pselaphodes anhuianus Yin & Li, sp. n. (Anhui), Pselaphodes daii Yin & Hlaváč, sp. n. (Sichuan), Pselaphodes grebennikovi Yin & Hlaváč, sp. n. (Yunnan), Pselaphodes hainanensis Yin & Li, sp. n. (Hainan), Pselaphodes kuankuoshuiensis Yin & Li, sp. n. (Guizhou), Pselaphodes longilobus Yin & Hlaváč, sp. n. (Hunbei, Yunnan), Pselaphodes monoceros Yin & Hlaváč, sp. n. (Xizang), Pselaphodes pengi Yin & Li, sp. n. (Sichuan), Pselaphodes tiantongensis Yin & Li, sp. n. (Zhejiang) and Pselaphodes wrasei Yin & Li, sp. n. (Yunnan). Labomimus sichuanicus Hlaváč, Nomura & Zhou (Sichuan) is redescribed and illustrated based on a paratype and the material from the type locality. Two recently described species, Pselaphodes tibialis Yin & Li (Yunnan), and Pselaphodes venustus Yin & Li (Yunnan), are transferred to Labomimus (comb. n.) due to the presence of a median metaventral fovea. New locality data is provided for Pselaphodes aculeus Yin, Li & Zhao (Anhui, Fujian, Guangxi, Hainan, Yunnan), Pselaphodes maoershanus Yin & Li (Guangxi, Guizhou), Pselaphodes tianmuensis (Zhejiang, Anhui, Fujian, Jiangxi, Guangxi) and Pselaphodes pectinatus Yin, Li & Zhao (Hainan), with the aedeagus newly illustrated for the latter species.

Comparative notes. Males of the new species can be readily separated from those of the only known congener, D. pengzhongi, by the unmodified antennae, the pronotum lacking tufts of long golden setae near the anterior margin, the much larger metaventral processes, and the aedeagus has broader parameres. Dayao pengzhongi has modified antennomeres IX and pronotum, and the aedeagus has relatively much thinner parameres (Yin et al. 2011b: 51, figs 11-13).
Distribution. Southwest China: Sichuan. Biology. Adults were collected by sifting leaf litter in a mixed forest. Etymology. The new species is named after the type locality, E'mei Shan Mountain. Notes. A female specimen (in pcPH) from Nibashan Mt., (Daxiangling Mts., ca. 50 km. W E'meishan) has slightly greater body size, and has each eye composed of about 20 facets. An associated male from Nibashan is needed for species identification.
Description. Male (Fig. 1B). Length 3.52-3.77. Head slightly longer than wide, HL 0.70-0.72, HW 0.60-0.65; eyes each composed of about 30 facets. Antennal clubs as in Fig. 3A. Pronotum (Fig. 3B) slightly longer than wide, PL 0.70-0.71, PW 0.65-0.69, roundly expanded at anterolateral margins. Elytra wider than long, EL 0.87-0.92, EW 1.22-1.26. Metaventral processes (Fig. 3C) long, curved anteriorly at apices. Procoxae, protrochanters and profemora spinose at ventral margin (  Comparative notes. This species is close to L. jizuensis and L. simplicipalpus (both described below) in sharing similar modifications of the antennae and legs. Labomimus fimbriatus and L. simplicipalpus share a symmetric aedeagal median lobe. The two species can be separated by the larger size, nearly symmetric antennomeres X, and more slender aedeagus in L. fimbriatus, while L. simplicipalpus is much smaller in size, has strongly asymmetric antennomeres X, and the aedeagus is more robust. Labomimus jizuensis can be separated from both former species by the clearly asymmetric aedeagal median lobe.
Distribution. Southwest China: Yunnan. Biology. Adults were commonly sifted from mixed leaf litter in shrubs and forests and are abundant in litter from appropriate habitats.
Etymology. The Latin word 'fimbriatus' means 'having a fringe, fringed', referring to the fringed apical portion of the metatibiae of the new species. Diagnosis. Reddish brown; length 3.54-3.64; postgenae rounded laterally; antennomeres IX-XI enlarged; IX-X modified in male; pronotum roundly expanded laterally at anterolateral margins; male with short metaventral processes; metacoxae simple; aedeagus with asymmetric median lobe.
Female. Unknown. Comparative notes. Labomimus jizuensis is closely allied to L. fimbriatus and L. simplicipalpus as discussed above, it can be readily separated from both species by the clearly asymmetric aedeagal median lobe.
Distribution. Southwest China: Yunnan. Biology. Individuals were collected by sifting litter and moss in mixed forests. Etymology. The new species is named after the locality where the two paratypes were collected, Jizushan Mountain.  Diagnosis. Reddish brown; length 3.40-3.69; postgenae broadly expanded laterally; antennomeres IX-XI enlarged, simple in both sexes; pronotum rounded at anterolateral margins; male with short metaventral processes; metacoxae spinose ventrally; aedeagus with asymmetric median lobe.

Labomimus sichuanicus
Redescription. Male (Fig. 4B). Comparative notes. This species is placed in the same group as L. shibatai Sawada, L. dabashanus Yin & Li, and L. schuelkei Yin & Li by sharing the laterally expanded postgenae. Labomimus sichuanicus is closest to L. schuelkei by sharing the postgenae being largely expanded laterally together with a thickened posterior margin, and the strongly elongate antennomeres V-VIII. The two species can be readily separated by the simple antennomeres IX-X, and the aedeagus with a much broader median lobe in L. sichuanicus, while L. schuelkei has strongly modified antennomeres IX-X, and the aedeagal median lobe is strongly narrowed dorsoventrally.
Biology. Individuals were sifted from mixed broad-leaved and bamboo leaf litter in a bush.
Remarks. This species was described from three males and two females from Qingchengshan Mountain (type locality) and Wolong Natural Reserve of the Sichuan Province. The holotype and paratypes preserved in the Institute of Zoology, Academia Sinica, Beijing cannot be located at this time (Zhou per. comm.). The descriptions and illustrations provided by Hlaváč et al. (2000: 150) as well as a comparison with a paratype housed in NSMT leave no doubt that the material listed above is conspecific with the holotype.   Included species. Nine species are placed in the tianmuensis-group (here proposed), seven are described here as new: P. anhuianus sp. n., P. daii sp. n., P. hainanensis sp. n., P. kuankuoshuiensis sp. n., P. longilobus sp. n., P. tianmuensis Yin, Li & Zhao, P. tiantongensis sp. n., P. wrasei sp. n., P. yunnanicus Hlaváč, Nomura & Zhou.
Diagnosis (based on male features). Medium to large in size (usually greater than 3 mm); apical three antennomeres enlarged; antennomeres IX slightly modified, with a disc-shaped process at apices, X-XI simple; protrochanters and profemora spinose at ventral margins; mesotrochanters usually with multiple ventral spines, mesofemora simple; metatrochanters and metafemora always simple; aedeagus with asymmetric median lobe, apical portion usually bent leftwards.
Discussion. Pselaphodes tianmuensis Yin, Li & Zhao was recorded from a number of localities in China (Yin et al. 2010(Yin et al. , 2011a. Putting aside the differences of aedeagal structure, populations from these localities present a relatively stable combination of male sexual characters; especially they share similar antennal modifications. Consequently, all of these were assigned to one, wide-spread species pending discovery of evidence leading to a different conclusion. Recently, when working on the material included in this paper, we found populations with two aedeagal forms that have a sympatric distribution (described as P. anhuianus and P. longilobus below). This geographical evidence proved not only the existence of two different species, but also the fact that other populations with different aedeagal forms cannot be treated as conspecific with P. tianmuensis. Hence we reevaluate the specific limit of P. tianmuensis and divide it into nine species.
Species identification of the group largely lies on the aedeagal from, the structure of the endophallus, the form of the metaventral processes, and the distribution. Further notes on these species, if any, will be provided in the 'Comparative notes' of the respective species. Diagnosis. Reddish brown; length 3.00-3.31; postgenae rounded laterally; antennomeres IX-XI enlarged; antennomeres IX modified in male; pronotum rounded at anterolateral margins; male with large metaventral processes; metacoxae simple; aedeagus with asymmetric median lobe.
Comparative notes. This species can be separated from the other members of the group primarily by the large, apically concaved metaventral processes, the more robust aedeagus with short apical portion of the median lobe, the structure of aedeagal endophallus, and its distribution.
Distribution. East China: Anhui; Central China: Hubei. Biology. Adults were collected by sifting mixed leaf litter in forests.

Etymology.
The new species is named after the province where the type locality is located.
Notes. Slight differences in body size and structure of the aedeagal endophallus were observed between specimens from Tianzhushan Mountain and Dabieshan Mountain. Since both localities belong to the Dabieshan Mountain Range, and all specimens were collected at low altitude (below 1000 m), the differences are considered to be intraspecific variation. Diagnosis. Reddish brown; length 3.50-4.43; postgenae rounded laterally; antennomeres IX-XI enlarged; antennomeres IX modified in male; pronotum rounded at anterolateral margins; male with long, sharp metaventral processes; metacoxae simple; aedeagus with asymmetric median lobe.

Distribution. Southwest China: Sichuan.
Biology. Adults were sifted from moss and mixed leaf litter in forests. Etymology. The new species is named after Cong-Chao Dai, co-collector of the type series.
Comments. The single male from Hailuogou has the aedeagal endophallus being slightly different to the males from Er'langshan Mountain. Though this difference is currently considered to be intraspecific variation, we choose a conservative approach here and exclude this specimen from the type series. Diagnosis. Reddish brown; length 3.14-3.43; postgenae rounded laterally; antennomeres IX-XI enlarged; antennomeres IX modified in male; pronotum rounded at anterolateral margins; male with broad metaventral processes; metacoxae simple; aedeagus with asymmetric median lobe.
Comparative notes. This species can be separated from the other members of the group by the short, apically narrowed metaventral processes, the apically rounded median lobe of the aedeagus, the structure of the aedeagal endophallus, and its distribution.
Distribution. Southwest China: Guizhou. Biology. Adults were sifted from leaf litter along a road in a forest. Etymology. The new species is named after the type locality, Kuankuoshui Natural Reserve. Diagnosis. Reddish brown; length 3.31-3.37; postgenae rounded laterally; antennomeres IX-XI enlarged; antennomeres IX modified in male; pronotum rounded at anterolateral margins; male with long metaventral processes; metacoxae simple; aedeagus with asymmetric median lobe.
Comparative notes. The Pselaphodes tianmuensis group is based on this species. Pselaphodes tianmuensis can be separated from the other members of the group by the short, apically narrowed metaventral processes combined with the apically rounded median lobe of the aedeagus, the structure of the aedeagal endophallus, and its distribution.
Notes. The structure of aedeagal endophallus varies slightly among the populations from the listed localities. At this time we are not able to separate these populations at the species level. Diagnosis. Reddish brown; length 3.28-3.45; postgenae rounded laterally; antennomeres IX-XI enlarged; antennomeres IX modified in male; pronotum rounded at anterolateral margins; male with short metaventral processes; metacoxae simple; aedeagus with asymmetric median lobe.
Female Comparative notes. This species can be separated from the other species of the group by the thin, elongate metaventral processes, the thin median lobe of the aedeagus, the structure of the aedeagal endophallus, and its distribution.
Comments. The male pro-and metatibiae of this species are uniquely modified. Populations from different localities have the aedeagus differing in the apices of median lobe and endophallus. Since the male external features are quite stable, all populations are treated as one, wide-spread species.  Diagnosis. Reddish brown; length 3.21-3.55; postgenae rounded laterally; antennomeres IX-XI enlarged; VII and IX-XI modified in male; pronotum rounded at anterolateral margins; male with long, broad metaventral processes; metacoxae simple; aedeagus with asymmetric median lobe.
Comparative notes. This distinct species can be readily separated from all other members of the genus by the antennomeres IX being largely projecting mesally, the modified antennomeres VII, and the aedeagus with a long, apically rounded median lobe.
Comparative notes. This unusual Pselaphodes species has simple maxillary palpomeres II and IV, with palpomeres III only slightly projecting laterally on the anterolateral margins. This form of maxillary palpi together with the modified clypeus in the male is not known in any other species of the Pselaphodes complex of genera. These two characters, in combination with the form of the antennal clubs, and the greatly elongate metaventral processes readily separate the new species from all other congeners of the genus. The generic limit of Pselaphodes is expanded based on this species. The form of maxillary palpi seems to be occasionally variable within genus (also see comments on Labomimus simplicipalpus above). An extensive species-level phylogenetic analysis is needed for the determination of the taxonomic placements of these atypical species. Description. Male (Fig. 25B). Length 3.41-3.50. Head longer than wide, HL 0.76-0.78, HW 0.74-0.75; eyes each composed of about 50 facets. Antennal clubs as in Fig. 27A. Pronotum (Fig. 27B) slightly longer than wide, PL 0.78-0.79, PW 0.74-0.75, rounded at anterolateral margins. Elytra wider than long, EL 0.94-0.99, EW 1.32-1.35. Metaventral processes long, apically broadened (Fig. 27C). Protrochanters and profemora strongly spinose at ventral margins (Fig. 27D), protibiae with small apical spur (Fig. 27E); mesotrochanters with distinct ventral spines, mesofemora with small ventral spine (Fig. 27F); metatrochanters and metafemora simple (Fig. 27G). Abdomen broad at base and narrowed apically, AL 0.93-0.94, AW 1.31-1.37. Sternite IX as in Fig. 27H. Aedeagus length 0.60, with asymmetric median lobe (Figs 27I-K).
Female. Unknown. Comparative notes. The new species has unique, modified antennomeres VI, combined with the slightly modified antennomeres VII, the enlarged antennomeres IX with a round apical process, the metaventral processes each with a preapical denticle on the upper surface, and the aedeagus with an apically greatly broadened median lobe, it can be quickly separated from all other species of the genus. Currently there is no other Pselaphodes species known to process modified antennomeres VI in the male.
Distribution. Southwest China: Sichuan. Biology. Individuals were sifted from leaf litter along roads in forests.
Etymology. This species is named after Zhong Peng, co-collector of the type series.