A new species of genus Nippononebria Uéno ( Coleoptera , Carabidae , Nebriini ) from Changbai Mountain , Jilin Province , China , the first species of the genus confirmed from the Asian mainland

Th e authors describe a new species, Nippononebria changbaiensis sp. n. (type locality: Changbai Mountain, 42.034004°N, 128.055854°E, 2000–2600 m, Jilin Province, PR China), which represents the fi rst confi rmed record of the genus from the Asian mainland. Th ey also provide a review of the taxonomic history of the genus and a key for distinguishing adults of subgenus Nippononebria species.


Introduction
Nippononebria was fi rst described by Uéno (1955) as a subgenus of Nebria Latreille (1802) to include two Japanese species, Nebria chalceola Bates (1883) and Nebria pusilla Uéno (1955), both from Honshu Island, with the latter designated as type species.Habu (1958) revised Nippononebria, recognized it as a distinct genus, and described a new species, Nippononebria kyushuensis, from Kyushu Island, and a new subspecies, Nippononebria pusilla teres, from Honshu Island.Nakane (1960) described two new subspecies, Nippononebria chalceola horioi and Nippononebria pusilla yatsuana, and later (Nakane 1979) described a new species, Nippononebria sawadai.All three of these taxa were recorded from restricted areas on Honshu Island.Subsequently, N. pusilla teres has been recognized as a junior synonym of N. pusilla pusilla (Uéno) (Habu 1975), and N. kyushuensis has been treated as either a distinct species (Lorenz 2005) or as a subspecies of N. chalceola (Nakane 1974;Ledoux and Roux 2005).As a result of this taxonomic history, the known Nippononebria fauna, as recently as the mid-1990s, comprised only three or four species, two of them represented by two or three subspecies, all of them restricted to the islands of Japan, and all but one of these taxa (N.kyushuensis) restricted to Honshu Island.Kavanaugh (1995) broadened the generic concept of Nippononebria by including three western Nearctic species, Nebria virescens Horn (1870), Nebria altisierrae Kavanaugh (1984), and Nebria campbelli Kavanaugh (1984), in a new subgenus, Vancouveria.Although members of these Nearctic species diff er from those of species of subgenus Nippononebria in some conspicuous features, such as in having antennomere 4 [mistakenly cited repeatedly as "antennomere 3" in Kavanaugh (1995)] without (or with extremely sparse) pubescence on the apical one-third, (the apical one-third of antennomere 4 is distinctly pubescent in members of the nominate subgenus), numerous characters of external and male and female genitalic form and structure suggest very close phylogenetic relationship between these taxa.Ledoux and Roux (2005) recognized this close relationship but ranked these taxa as diff erent subgenera of genus Nebria, based on their hypothesis of relationships among Nebria subgenera.Lorenz (2005) followed Habu (1958) in treating Nippononebria as a genus distinct from Nebria and included Vancouveria as a subgenus of Nippononebria, a classifi cation with which we agree.As thus conceived, Nippononebria was a genus with a north-temperate trans-Pacifi c distribution, with the Nearctic component restricted to the west coast of North America, from southern British Columbia to central California, and the known Palaearctic component restricted to Honshu and Kyushu Islands of Japan.
In 1992, Li and Liang (Li 1992) described a new species of Nippononebria from Jilin Province, China under the name Nipponebria [sic] xiaoxinganensis.Th ierry Deuve, of the Museum National d'Histoire Naturelle in Paris, identifi ed the holotype as a specimen of Diacheila polita Faldermann, a member of the tribe Elaphrini, in 1999; and Ledoux et al. (2003) formally established this synonymy.So this fi rst record of Nippononebria from the Asian mainland proved invalid.However, in 1998, while sorting through undetermined carabid material in the collection of the Institute of Zool-ogy of the Chinese Academy of Sciences in Beijing, the senior author noticed two unusual Bembidion-sized specimens among materials collected by Professor Peiyu Yu and her assistant on remote Changbai Mountain, Jilin Province, in July 1987.Careful examination of these specimens revealed that they are nebriines with nearly all of the external features characteristic of members of Nippononebria (sensu stricto), but also with several features distinguishing them from members of all previously described species.Subsequent genitalic dissections have confi rmed both basic similarities with other Nippononebria members and diff erences from them.
Th e purpose of this contribution is to describe this new species of Nippononebria, provide a key for distinguishing members of this species from those of other known species in subgenus Nippononebria, and report this fi rst valid record for the genus on the Asian mainland.

Materials and methods
Specimens examined are housed in the California Academy of Sciences, San Francisco, U.S.A (CAS) and the National Zoological Museum of China, Institute of Zoology, Beijing, China (IOZ).
Methods used in the present study, including dissection techniques and criteria for ranking taxa as distinct species, were as described in Kavanaugh (1979).Th e only measurements used are: standardized body length (SBL), which equals the sum of the lengths of the head (measured from apex of clypeus to a point on midline at level of posterior margin of compound eye), pronotum (measured from apical margin to basal margin along midline), and elytra (measured along midline from apex of scutellum to apex of the longer elytron); and ratio of pronotal width (transverse width across pronotum measured at the widest point) to pronotal length (distance from anterior margin to posterior margin measured along midline (i.e.not including apical and basal angles)).Digital photographs of dorsal habitus, pronotum, and male genitalia were taken using an Automontage imaging system by Syncroscopy with a Leica M420 dissecting microscope.Etymology.Th e species epithet is an adjective in the nominative singular derived from the name of the type locality, Changbai Mountain, and referring to it.

Taxonomy
Diagnosis.Adults of this species can be distinguished from those of all other species of subgenus Nippononebria by the following combination of character states: size very small (SBL of male less than 6.5 mm); head, pronotum, and elytra shiny, with faint but distinct blue-green metallic refl ection; pronotum relatively short and broad, distinctly wider than head across eyes, ratio of pronotal width to length = 1.4-1.5, basal margin distinctly wider than apical margin, with basal sinuation of lateral margin long and shallow, basal angles rectangular, lateral explanation narrow anteriorly and at middle, markedly broadened basally; elytral silhouette subovoid, relatively short, widest distinctly anterior to middle, elytral microsculpture comprised of moderately impressed and markedly transverse meshes, humeral carina and tooth slightly developed, striae markedly punctate, intervals very slightly and smoothly convex; hindwings full-sized; thorax coarsely punctate ventrally (most distinctly so on mesepisterna and metepisterna, but also on prosternum and proepisterna anteriorly, on mesosternum, and on metasternum laterally).
Description.Body (Fig. 1) size very small for a Nippononebria or a nebriine, SBL males 5.8-6.0 mm; head piceous or reddish brown, without pale spot or spots on vertex, pronotum and elytra piceous or reddish-brown, legs brown or reddish-brown, venter brown or reddish-brown; dorsum with faint but distinct metallic blue-green refl ection (most evident on elytra), venter without metallic refl ection; frons smooth or slightly punctate laterally, vertex smooth or nearly so; head slightly shiny, pronotum and elytra markedly shiny, microsculpture on frons and pronotum faintly impressed with sculpticells comprised of broken isodiametric meshes, microsculpture on elytra moderately impressed with sculpticells comprised of markedly transverse meshes.
Head.Size and width relative to pronotum average for genus.Genae and occiput not infl ated, head very slightly constricted behind eyes.Eyes medium in diameter and convexity for genus.Vertex with one pair of supraorbital setae.Antennae moderately elongate; scape slightly short and slightly arcuate, markedly narrowed basally, with one anterodorsal seta subapically; pedicel with one ventral seta subapically; fl agellar antennomeres moderately elongate, medium width, antennomeres 3 and 5 subequal in length, antennomere 4 with apical one-third distinctly pubescent, antennomeres 5 to 11 distinctly pubescent.Labrum with apical margin truncate or slightly concave, with four or fi ve setae.Clypeus with apical margin truncate or slightly concave.Glossal sclerite (ligula) with apicoventral margin moderately and bluntly toothed, with one pair of ligular setae apicoparamedially; paraglossae separate, minute, dentiform.Labium with penultimate labial palpomere trisetose anteriorly, minutely unisetose posteroapically.Submentum with two pairs of lateral setae and one pair of medial setae.
Pronotum.Size relative to elytra large, markedly wide, and slightly short for genus; shape (Fig. 3) subquadrate, markedly convex, basal margin distinctly wider than apical margin; lateral margins slightly arcuate, with basal sinuation long and shallow; lateral explanation present throughout pronotal length, narrow anteriorly and at middle, markedly broadened basally; basal margin straight; apical angles moderately long, slightly narrow, and moderately rounded; basal angles rectangular or slightly acute, not projected posteriorly, not apically dentate; lateral margination (also called "lateral bead") uniformly present throughout, moderately wide and moderately impressed; anterior margination present in lateral 30-40%, absent medially, moderately wide and moderately impressed; anterior transverse impression broad and slightly shallow; posterior transverse impression narrow and very deep; basal foveae deep, extremely broad, slightly divergent basally, without or with a faint and broad tubercle medially; one pair each of midlateral and basolateral setae present.
Legs.Medium length for genus; hind coxae with one seta basally and one seta apically.Hind trochanters kidney-shaped, medium length, truncate or broadly rounded apically.Middle tibiae with dorsal sulcus present, extended from near base to apical one-third, with brush of sparse setae present dorsosubapically.Tarsi with very sparse, minute setae dorsally; protarsi of males with basal three tarsomeres broadened and with pads of adhesive setae ventrally; hind tarsi with ventroapical margin of tarsomere 4 truncate.
Abdomen.Sternum II (fi rst visible sternite) sparsely and coarsely punctate, other sterna impunctate; suture between sterna III and IV complete, distinct throughout; sternum III without setae; sterna IV to VI with one pair of posterior paramedial setae, without paralateral setae; sternum VII (last visible sternite) of males with one pair of posterior paramedial ("anal") setae.
Male genitalia.Median lobe of aedeagus (Fig. 4A-B) with basal bulb rounded and markedly closed basally, dorsobasal piece present as a large, simple mid-sagital fi n dorsally; mid-shaft moderately thick, slightly narrowed basally, with its axis bent to a slightly acute (< 90 degrees) angle (in lateral aspect), circular (in cross-section), with right face of mid-shaft unmodifi ed; preapical-shaft narrow and moderately tapered apically, ventral margin straight or slightly and smoothly concave (in lateral aspect), broad, slightly tapered basally and apically and faintly defl ected right (in dorsal aspect), with apical orifi ce slightly defl ected right (in apical aspect); apical lamella (Fig. 4A) short, narrow, narrowly rounded apically, nearly centered on preapical shaft (in ventral aspect), plane of lamellar face horizontal (in apical aspect).Parameres asymmetrical, with right slightly longer than left; right paramere (Fig. 4C) slender, more fully sclerotized apically but with more faintly sclerotized areas subapically on anterior and posterior margins; left paramere (Fig. 4D) broad, slightly narrowed and only faintly sclerotized apically.
Female genitalia.No female specimens are known.

Geographical distribution.
Th is species is known only from the type locality, on Changbai Mountain, on the border between Jilin Province, China, and North Korea (Fig. 5).
Habitat distribution.According to Professor Peiyu Yu (personal communication), the two known specimens of N. changbaiensis likely were collected under stones above treeline on the north slope of Changbai Mountain.Th ere is some diffi culty, however, in determining the precise locations where these specimens were collected on the mountain.To the unaided eye, there is little remarkable about adults of this species, and they could readily be mistaken for adults of some Bembidion species (which would be both diverse and abundant in this area) rather than a nebriine; hence there would have been little reason for Professor Yu to mark their capture in memory."Tianchi", which appears on the labels for both specimens, means "mountain lake", suggesting that they were collected near the lake that occupies the summit crater.Th e holotype label also mentions the "waterfall", which is a well-known feature at the head of the valley leading to the rim of the summit crater and lake.Th e holotype's label cites an elevation range of 2000-2600 m and the paratype's label cites an elevation of 2000 m.Th e level of the lake shore is at about 2200 m elevation, the base of the waterfall at about 2000 m, and the top of the waterfall and fl oor of the upper valley leading directly to the lake at about 2200 m.We conclude that both specimens were probably collected under stones along the stream course that includes the large waterfall, perhaps both above and below that feature.We have used this feature to estimate the geographical coordinates specifi ed in the type locality description.
Phylogenetic relationships.Based on characters of external morphology and form and structure of male genitalia, N. changbaiensis is clearly a member of genus Nippononebria and of the nominate subgenus.Th e very small body size, unusual body shape (especially the elytral silhouette), and thoracic venter coarsely punctate laterally distinguish members of this species from those of the Japanese species, as well as from members of all Vancouveria species.We found no features that suggest a closer relationship of N. changbaiensis to any one of the Japanese than to any other; it is probably the sister species to a clade including the three Japanese species of subgenus Nippononebria.
Geographical relations with most closely related species.Th e known geographical range of N. changbaiensis, confi ned to a single locality on the Asian mainland, is allopatric with respect to the ranges of the three other species of subgenus Nippononebria, all restricted to Japan (Fig. 5).Nippononebria pusilla and N. sawadai occur only on Honshu Island (at high elevations in restricted parts of central and northern Honshu, respectively); and N. chalceola ranges more widely, and at lower elevations, on both Honshu and Kyushu Islands.

Comparisons
Adults of the four species of Nippononebria (sensu stricto) are easily distinguished using the key provided below.We have avoided the use of gender-specifi c characters in distinguishing the species here because females of N. changbaiensis are not yet known.We also take this opportunity to correct two crucial errors in Kavanaugh's (1995) key to the subgenera of Nippononebria.He incorrectly used the absence or extremely sparse presence of pubescence on "antennomere 3" and the presence of "two pairs of posterior paramedial setae" on abdominal sterna "III to V" (actually sterna IV to VI) to distinguish members of his new subgenus Vancouveria from those of subgenus Nippononebria.In fact, the antennomere on which the diff erence in pubescence occurs is antennomere 4; and, as correctly pointed out by Ledoux and Roux (2005), members of both subgenera have only one pair of posterior paramedial setae on the designated sterna.It is only on sternum VII (the so-called "apical" or "anal" sternite) of both males and females of Vancouveria spp. that two pairs of setae are seen in most individuals, whereas only females of Nippononebria spp.have two pairs of setae and males have only a single pair.We incorporate these features in our new key, couplet 1, which distinguishes the subgenera.Th orax coarsely punctate ventrally (most distinctly so on mesepisterna and metepisterna, but also on prosternum and proepisterna anteriorly, mesosternum and metasternum laterally); size very small (SBL of male less than 6.5 mm); elytral silhouette (Fig. 1

Figure 2 .
Figure 2. Photographs of labels for type specimens of Nippononebria changbaiensis sp.n.A Holotype B Paratype.

Figure 5 .
Figure 5. Map of the Sea of Japan and adjacent land areas, showing the known geographical distribution of Nippononebria (sensu stricto) Uéno and included species: solid yellow circle N. changbaiensis sp.n.C N. chalceola (Bates) P N. pusilla (Uéno) S N. sawadai Nakane (n.b.Only exemplar localities shown for N. chalceola and N. pusilla).Scale line = 400 km.