New or little-known species of the genus Amphimenes Bates, 1873 (Coleoptera, Carabidae, Lebiinae) from Vietnam

Abstract Twelve new species of the genus Amphimenes Bates, 1873 are described from Vietnam: Amphimenes maculatus sp. n., Amphimenes bidoupensis sp. n., Amphimenes gracilis sp. n., Amphimenes montanus sp. n., Amphimenes giganteus sp. n., Amphimenes medius sp. n., Amphimenes minutus sp. n., Amphimenes rufipes sp. n., Amphimenes reflexicollis sp. n., Amphimenes planicollis sp. n., Amphimenes nitidus sp. n., and Amphimenes kabakovi sp. n.. Amphimenes rugulipennis Bates, 1892, comb. n., is transferred from the genus Brachichila Chaudoir, 1869 and is redescribed from fresh material. A key to all congeners is provided, these being arranged into five new species-groups. Adults of the rugulipennis- and piceolus-groups show subcortical habits, while those of the medius-, rufipes- and planicollis- groupsare herpetobiotic, resulting in such morphological adaptations as partly reduced eyes, missing wings and adnate elytra.


Introduction
Th e genus Amphimenes Bates, 1873 is still a poorly-known member of the subtribe Pericalina, Lebiini. It was established for the only, and type, species A. piceolus Bates, 1873 from Japan (Bates 1873). Two further congeners, A. asahinai Nakane, 1957, andA. ryukiuensis Habu, 1964, were added from Taiwan and Japan (Ryukyus; Amamioshima Is., Kyushu), respectively, while the genus was revised by Habu (1964Habu ( , 1967. He reviewed and keyed all these species, and pointed out that the earlier records of A. piceolus in Taiwan and Fujian [Fukien], southern China (Jedlička 1940(Jedlička , 1953(Jedlička , 1963 actually belonged to diff erent species. In addition, A. rugulipennis (Bates 1892), comb. n., has hitherto been considered as a member of the genus Brachichila Chaudoir, 1869, this being corrected here.
Among the other members of Oriental Pericalina, Amphimenes seems to be especially similar to the genera Brachichila and Dolichoctis Schmidt-Goebel, 1846, diff ering well from both chiefl y by the combination of a well-developed median tooth on the mentum, a highly characteristic cross-striation on the elytra and some other characters. Th e adults of at least some winged species (A. piceolus) have been known to live under the bark [of dead trees] (Habu 1964(Habu , 1967.
During a few recent expeditions of the Russia-Vietnam Tropical Center to Vietnam, I collected eight species of the genus, all of them but B. rugulipennis being new. Only three of these new species showed subcortical habits and well-developed wings, while the remaining ones dwelled under or in logs or larger branches on the soil surface and were wingless following their habits. Th is proved to also be true of four species of fi ve further described here as new, these collected by O. N. Kabakov in Vietnam fi ve decades ago. As a result, all congeners are keyed here, with the Vietnamese species described or redescribed. Taking new characters into account, I also think it advisable now to refi ne the diagnosis of the genus.
One to 18 specimens per species studied were measured concerning the following parameters: body length from the apex of the mandible to the apex of the abdomen/elytra, head width across eyes (HW), maximum pronotal and elytral widths (PW and EW, respectively), length of pronotum along its mid-line (PL), length (MESL) and width (MESW) measured along the outer and anterior margin of the metepisternum, respectively, length from the basal margin to the apex of the elytra (EL), and distances between the elytral basal margin and the discal setigerous pores (D1, D2 and D3). Th e indices PW/HW, PW/PL, EL/EW, EW/PW, MESL/[MES]W, as well as D1/EL, D2/EL and D3/EL, were analysed.
Holotypes and paratypes of the species described here are deposited in the Zoological Institute of the Russian Academy of Sciences, St. Petersburg (ZISP), Zoological Museum of the Moscow State University (ZMMU), and the author's reference collection at the A. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences (SIEE), as indicated hereafter.
Redescription. Small-to medium-sized pericaline lebiines, either unicoloured or with a pale pattern composed of two, posthumeral and subapical, rounded, yellow spots on each elytron, latter spots adjoining suture; refl exed side margins of both pronotum and elytra, antennae, mouthparts, legs, labrum and clypeus usually paler, often contrastingly so. Body glabrous, except for underside microscopically ciliate and pronotum almost indistinctly so in some species. Forebody dorsum dull due to an almost granulate isodiametric microsculpture occupying head, pronotum and scutellum, sometimes somewhat shining because of a weaker microsculpture which, in addition, forms slightly transverse meshes behind pronotal front margin and base. Elytral microsculpture composed of very fi ne and dense transverse lines or very narrow transverse meshes, anyway contributing to dorsum's iridescence, rarely coarse and isodiametric. All but one congener show a highly characteristic cross-striated sculpture occupying entire disc or, rarely, only elytral base; this cross-striation, combined with microsculpticells or lines, becoming increasingly oblique outwards, resulting in both being conspicuously oblique posterolaterad on intervals 5 to 8.
Eyes varying from large and hemispherical to small and flat. Labrum trapezoidal ( Fig. 1), a little narrowing forwards, with front angles rounded; anterior margin slightly sinuate, with six setae of gradually decreasing length inwards. Last maxillary palpomere narrowing apicad, longer than penultimate one. Submentum with a pair of strong setae; another pair situated at base of a large median tooth of mentum, latter rounded apically, about half as long as wide lateral lobes (Fig.  2). Ligula well-developed, sclerotized apically and not so strongly basally, fairly narrow, with two pairs of apical setae, inner much longer than outer; paraglossae membranous, wide, a little longer than ligula, each with four setae over outer margin. Penultimate labial palpomere with two preapical setae drawn together; proximal and distal setae of anterodorsal and anteroventral position, respectively; last labial palpomere subcylindrical, slightly narrowing apicad. Antennae long to short, pubescent from apical half of antennomere 4 onward, some species (A. medius, A. minutus, A. rufipes) showing apical half of antennomere 3 spa s ly ciliate along outer margin; 3 rd antennomere 1.2-2.05 times as long as 2 nd ; 7 th to 9 th 1.22-3.34 times as long as wide.
Pronotum rather fl at, strongly transverse to about as long as wide, weakly cordate, deeply emarginate anteriorly, with protruding and fairly narrow front angles, rather strongly rounded on sides, somewhat narrowing basad, broadest before middle, i.e. level to anterolateral setigerous pore at which side margin often slightly angulate; latter moderately strongly sinuate to straight before posterior angles, these varying from obtuse to almost indistinct due to pronotal base increasingly oblique forward towards posterolateral setigerous pore. Front margin with a very narrow but distinct polished bead; side margin rather strongly explanate-refl exed, narrow anteriorly and gradually broadening basad; basal transverse depression conspicuous to weak, when well-developed, ca 0.15 times as long as pronotum along mid-line, latter varying from deep to superfi cial; lateral basal foveae weak to indistinct, each usually extended to the middle or anterior third as a very shallow depression running parallel to side margin; disc at middle with a pair of small and shallow paramedian foveae. Base slightly trilobed, with medial part mostly a little surpassing lateral lobes.
Metathorax longer in winged than in wingless species; accordingly, metepisternum much longer than wide (MESL/W=1. 35-1.73) in the former versus about as long as wide (MESL/W=0.78-1.02) in the latter.
Profemur rather strong. Claws serrate in basal two-thirds. Pretarsus with two or only one, distal, pair of setae beneath.
Aedeagus. Penis mostly rather stout, weakly arcuate, strongly bent to the right just behind basal ca s le and often twisted to the right behind the middle, with apical orifi ce rounded and shifted to the left; apical lamella rather small, of characteristic shape and structure in diff erent species. Microsculpture usually conspicuous, composed of iso- diametric to slightly longitudinal meshes predominantly developed over left side; right ventral side mostly longitudinally striate in basal half. Parameres moderately strongly reduced, left paramere subrectangular, right one small, rounded apically, with base long, narrow and hooked apically.
Female gonapophyse as in Fig. 3. Sexual dimorphism: male protarsomeres 1-3 dilated, each with an adhesive pubescence beneath, sternite 6 sometimes slightly desclerotized or weakly emarginate posteriorly, with one, lateral, pair of setae, versus not sinuate and with two pairs of setae in female. Males of two species show basal third of profemur underside furnished with a small tubercle instead of a pointed mesotrochanteral tubercle observed in males of most other congeners.
Geographic distribution. Th e range of the genus extends from Japan (Kyushu and Shikoku) in the north and east to at least southern Vietnam in the south, and Myanmar in the west. Winged congeners are certain to be much more widespread than wingless ones, implying still undescribed species of very local ranges to be discovered in unexplored montane regions of Indochina, Vietnam in particular.
Habits and habitats. All congeners inhabit forested areas, both montane and lowland. Original adult habits seem to be strictly subcortical. In southern Vietnam, species with such habits occur under bark (A. bidoupensis) or also in chapped bark of standing dead trees (A. rugulipennis, A. maculatus), never of fallen deadwood or logs. All of them are winged, some fl ying to light at night. Such soil-dwellers as A. medius, A. minutus, A. rufi pes and A. giganteus are certain to be derived, being adapted to living in leaf litter or cavities in logs or fallen larger branches. Th is has resulted in a few morphological adaptations, among them, the hindwings missing, the elytra wide, fused along the suture, with strongly rounded shoulders, while the eyes tending to be reduced to small and fl at. Th e latter contributes much to the head being narrower across the eyes while broader across the neck, all relative to body width. Only A. giganteus among the members of the latter ecological group sometimes occurs under bark, while the others have never been observed there. Four species from northern Vietnam show similar morphological adaptaptions, suggesting herpetobiotic habits as well.
In the Bi Doup -Nui Ba Nature Reserve, three to fi ve species live sympatrically, with up to four soil-dwellers among them occurring syntopically. Th is seems to also be true for elsewhere in Vietnam north of the Dalat Plateau because more than one species have been recorded from such localities as Tam  and predominantly winged species, with metepisternum distinctly longer than wide. Eyes either large and hemispherical or only slightly fl attened; posterior supraorbital seta situated level to or slightly behind eye back margin. 9(12) Elytral microsculpture composed of transverse meshes. Body length 5.8-7.0/5.5-6.8 mm. 10(11) Wings full, both metepisternum and elytra longer, ca 1.4-1.5 times as long as wide, latter less strongly rounded on sides (ex Habu, 1964
Th e group includes two species. ( Redescription. Body length 6.4-8.2/6.3-7.7 mm, width 2.7-3.5 mm. Dorsum black, head dark brown to black; refl exed side margins of both pronotum and elytra, legs, mouthparts and antennae reddish yellow. Underside dark brown; gula, prosternum, median part of mesoventrite, metaventrite and abdomen red, with abdominal sternites 4-6 darkened laterally as well as 6 in apical half. Epipleura mostly dark, brown to dark brown. Elytron with two, rounded, yellow spots, isolated both from each other and elytral margin. Of them, anterior spot usually larger, occupying intervals 3 to 8, laterally almost extending to shoulder, mostly not surpassing midway between D1 and D2; posterior spot occupying four inner intervals and not extending forward midway between D2 and D3. Left and right posterior spots widely adjoining, thus often merging into a common macula sinuate along suture posteriorly. 3 rd antennomere 1.58-1.76 (mean 1.65) times as long as 2 nd , 8 th 2.0-2.63 (mean 2.26) times as long as wide.

Amphimenes rugulipennis
Pronotum 1.51-1.60 (mean 1.56) times as wide as long, 1.40-1.48 (mean 1.44) times as wide as head, fairly strongly rounded laterally, broadest before middle, a little narrowing basad, distinctly but not strongly sinuate before hind angles, latter obtuse due to base increasingly oblique forward at extremities. Anterior margin strongly sinuate between strongly protruding and apically rounded front angles. Base medial part distinctly convex backward, with a narrow refl exed border almost reaching hind angles. Mid-line deep, deeper basad, not adjoining anterior bead and abruptly disappearing before transverse basal depression, latter sublinear and not deep; lateral basal foveae weak; paramedian foveae small and very shallow. Refl exed side margin indistinctly separated from disc convexity by a narrow fl at gutter.
Male profemur ventrally with a small but sharp tubercle in basal third. Penis (Figs 17,26,35) regularly arcuate, microsculpture very coarse, apical orifi ce bilobed due to a strongly sclerotized dorsolateral projection extending to about its middle. Apical lamella small and triangular in lateral view, with a small rounded membranous window on right dorsal side.
Other Description. Very similar to the preceding species, except as follows: Body smaller, 5.6-5.9/5.3-5.7 mm long, 2.3-2.5 mm wide. Paler side margin of pronotum broader, slightly entering pronotal disc. Underside, on average, darker, with gula same coloured as lateral parts of head; anterior paler spot on elytron about 1/2 spot length distant from base, always surpassing midway between D1 and D2, often reaching or almost reaching D2 level, mostly not extending outwards beyond stria 7; posterior spots usually somewhat angulate, starting midway between D2 and D3, widely adjoining along the suture.
Male profemur without ventral tubercle. Penis (Figs 18, 27, 36) with a very coarse microsculpture and left margin in dorsal view sinuate behind basal third. Apical orifi ce rounded but for a distinctly sclerotized dorsolateral projection (lobe), latter being much smaller and less strongly sclerotized than in A. rugulipennis. Apical lamella rather large, strongly bent upwards and entirely occupied by a membranous window on right dorsal side.
Eyes large, tempora short and rather abruptly extending into neck; posterior supraorbital seta situated level to eye back margin. Antennae long and surpassing pronotal base at least by last two joints, 3 rd antennomere 1.54-1.88 (mean 1.72) times as long as 2 nd , 8 th 2.29-2.75 (mean 2.47) and 1.89-2.21 (mean 2.05) times as long as wide in males and females, respectively. Pronotum 1.36-1.55 (mean 1.44) times as wide as long, 1.38-1.50 (mean 1.43) times as wide as head, similar to that of A. rugulipennis but the following characters: less convex, with less distinct basal transverse depression, broadest a little before middle; side margin slightly to rather strongly sinuate before hind angles, latter subrectangular due to base lateral parts sublinear and oblique only before posterolateral setigerous pore. Base medial part distinctly convex backwards, its border very shallow, especially so at middle. Mid-line rather shallow throughout its length, often shortly deeper where adjoining basal transverse depression; latter distinctly to weakly separated from disc convexity; lateral basal foveae weak but usually almost extended to anterior margin as very shallow depressions parallel to side margins. Paramedian foveae mostly shallow but distinct.
Last tarsomere often with proximal pair of ventral setae rudimentary or absent from some, rarely, all legs. Male profemur without ventral tubercle.
Diagnosis. Habitually, the present species is very similar to A. ryukyuensis, A. montanus sp. n. and, especially, A. gracilis sp. n. From the former species, it diff ers chiefl y in the combination of the larger and stouter body, namely, shorter elytra, longer pronotum, with sides distinctly sinuate before posterior angles. Th e latter character, together with the pronotum more strongly narrowing backwards, the narrower refl exed side border of the pronotum, and the longer metepisternum, separates it from A. montanus. Th e larger body and the wider pronotum, combined with the longer metepisternum, as well as certain peculiarities of penial structure, diff erentiate the present species from A. gracilis.
Material Life history. Th e species is very common all over its type locality, where it occurs under the exfoliating bark of standing dead trees and, in addition, it fl ights to light at night.
Name. Th e species name is derived from the species' type locality. Type locality: North Vietnam, 40 km NE of Th ai Nguen. Geographic distribution. Known only from the above two localities. Occurring at lower altitudes (~200-500 m a s l.) than do A. bidoupensis or A. montanus, also probably being allopatric with both. Description. Body length 6.7-7.8/6.5-7.6 mm, width 2.5-3.2 mm. Same coloured as A. bidoupensis but a little darker, with femora more strongly infuscate except at apices.

Amphimenes montanus
Eyes prominent to slightly reduced in size and a little fl attened; posterior supraorbital seta situated slightly behind eye back margin. Antennae long, 3 rd antennomere 1.58-1.70 times as long as 2 nd , 8 th 2.0-2.22 times as long as wide.
Pronotum 1.30-1.44 times as wide as long, 1.49-1.57 times as wide as head, weakly contracted basad, with side margin almost straight between antero-and posterolateral setigerous pores, hind angles subrectangular but rounded apically. Base medial part distinctly convex backwards, with a very shallow border, especially so at middle. Mid-line rather shallow throughout and shortly deeper where adjoining transverse basal depression; latter separated from disc convexity; lateral basal foveae weak. Paramedian foveae shallow but distinct.
Elytra same as in A. bidoupensis, 1.43-1.50 times as long as wide, and 1.51-1.55 times as wide as pronotum, with no depression between D2 and stria 6. D1/EL=0.

The medius-group
Either body colour uniform black or side margins of pronotum and elytra slightly paler; femora infuscated to dark brown entirely or except for at extremities; antennae, mouthparts, tarsi and usually also tibiae red. Antennae often slightly infuscated apicad. Eyes conspicuously to strongly reduced, posterior supraorbital setae situated far behind posterior eye margin; tempora long and smoothly extending into neck. Wings completely reduced; metepisternum very short, about as long as wide. Elytra fused along suture, oval, rather strongly rounded on sides, with strongly rounded shoulders. Discal setigerous pores on elytra either three or D1+D3; D1 and, when present, D2 being in anterior and posterior position, respectively (D1/ EL=0.10-0.14, D2/EL=0.61-0.76). Setigerous pores of umbilicate series uninterrupted or weakly divided into two, posthumeral and preapical, groups. Last tarsomere mostly with one, distal, pair of ventral setae, otherwise proximal pair rudimentary. Pronotum long, only 1.13-1.29 times as wide as long, non-ciliate; medial part of pronotal base nearly straight; refl exed side margin rather narrow, especially so anteriorly. Antennae long to very short, not reaching pronotal base. Elytral striae moderately deep throughout, intervals convex. Elytral microsculpture composed of strongly transverse meshes.
Th e group includes three sympatric and partly syntopic species of soil-dwelling habits. Description. Body length 8.5-10.6/8.3-10.2 mm, width 3.2-4.1 mm. Dorsum black, mouthparts and antennae red, clypeus and labrum mostly brown; refl exed side margin of pronotum dark brown to reddish-brown, that of elytra translucent reddish at the very base only. Gula brownish-red. Tarsi and tibiae, latter all along or apically, as well as all trochanters and procoxa red or brownish-red. Antennae often infuscated toward apex to brownish-red. Eyes rather small and slightly fl attened, a little longer than tempora; these smoothly extending into neck in dorsal view; posterior supraorbital seta situated about 1/3 distance between eye back margin and pronotal front margin. Frontal foveae fairly deep and reaching level to eye front margin. Antennae very long, surpassing pronotal base by last three or more joints, 3 rd antennomere 1.88-2.05 (mean 1.95) times as long as 2 nd , 8 th 2.73-3.36 (mean 3.11) times as long as wide.

Amphimenes giganteus
Pronotum subcordate, 1.18-1.26 (mean 1.22) times as wide as long, 1.37-1.49 (mean 1.43) times as wide as head, conspicuously sinuate before hind angles, with front angles pointed and approaching neck; hind angles very obtuse and strongly sloping forward. Base medial part weakly convex backward, often almost straight, with a very shallow border not extended to lateral lobes. Disc rather fl at, mid-line superfi cial throughout its length and weakly separated from transverse basal depression, lateral basal foveae weak, each usually almost extended to anterior margin as a very shallow submarginal depression parallel to side margin. Paramedian foveae lengthwise, very shallow to indistinct.
Proximal pair of ventral setae on last tarsomere rudimentary or absent. Male profemur without ventral tubercle.
Penis (Figs 22,31,40) long, narrow, weakly arcuate in lateral view and abruptly curved to the right behind the middle in dorsal view; apical lamella large, long, parallel-sided, widely rounded apically; apical orifi ce rounded; both ventral striae and microsculpture absent.
Diagnosis. Th e present species is easily recognizable among the other congeners by the combination of the large and wingless body, protruding outer angles of the elytral apical truncature, peculiar formula of discal setae, and other characters specifi ed above.  Description. Body length 5.7-7.2/5.5-7.0 mm, width 2.2-2.9 mm. Same coloured as A. giganteus, but a little paler: dorsum black, more rarely dark brown, often with head and pronotum a little paler; clypeus and labrum brown or reddish-brown; mouthparts, antennae and legs red; underside and femora, latter except at extremities, infuscated to dark brown; refl exed side margin of pronotum brownish-red; gula reddish, epipleura brownish.
Eyes rather small and fl attened, a little longer than tempora; these smoothly extending into neck in dorsal view; posterior supraorbital seta situated level to about 1/3 distance between eye back margin and pronotal front margin. Frontal foveae shallow. Antennae moderately long, surpassing pronotal base by approximately last joint only, 3 rd antennomere 1.40-1.58 (mean 1.47) times as long as 2 nd , 8 th 1.89-2.09 (mean 1.97) and 1.86-1.98 (mean 1.91) times as long as wide in males and females, respectively.
Pronotum 1.18-1.29 (mean 1.24) times as wide as long, 1.52-1.71 (mean 1.63) times as wide as head, with front angles protruding but slightly rounded apically and remote from neck; refl exed side margin narrow, especially so anteriorly, indistinctly sinuate or straight before hind angles. Base medial part weakly convex backwards, as wide as lateral lobes, these surpassing medial part and rather strongly rounded so that hind angles almost indistinct; basal border shallow and disappearing at about middle of lateral lobe. Mid-line superfi cial, not or hardly deeper basad, shortly deeper where adjoining basal transverse depression, latter very short, weakly to distinctly separated from a very convex disc, lateral basal foveae weak, without forward extensions along side margin. Paramedian foveae mostly indistinct.
Last tarsomere with distal pair of ventral setae only. Basal third of male profemur with a distinct but wide and obtuse ventral tubercle.
Penis (Figs 23, 32, 41) triangular in ventral view, strongly twisted to the right before apex, resulting in apical orifi ce of almost ventral position; apical lamella large subtriangular, with a rounded tip.
Diagnosis. Easily recognizable chiefl y by the combination of the medium-sized body, D1+D3 formula of discal setae, absent wings, etc. It diff ers well from A. minutus in the stouter body, less strongly reduced eyes and longer antennae. 8. Amphimenes minutus Fedorenko, sp. n. urn:lsid:zoobank.org:act:3D264770-BEDF-4258-BE9E-58E9BBB5443D Fig. 11 Description. Similar to the preceding species in many characters, especially body colour. Th e main diff erences are as follows: Body small, 5.3-6.3/5.1-6.0 mm long, 2.0-2.2 mm wide. Eyes very small and fl at, about as long as tempora; these very smoothly extending into neck in dorsal view; posterior supraorbital seta situated level to about midway between eye back margin and pronotal front margin. Antennae short, not reaching pronotal base; 3 rd antennomere 1.38-1.45 times as long as 2 nd , 8 th 1.63-1.76 times as long as wide. Pronotum longer, 1.13-1.15 times as wide as long, 1.44-1.47 times as wide as head, much less convex in posterior half. Base straight, with medial part wide and almost inseparable from lateral lobes. Mid-line superfi cial throughout its length, basal transverse depression weakly separated from disc convexity, lateral basal foveae longitudinal and rather distinct, somewhat extended forward as very shallow depressions not reaching level of anterolateral setigerous pore. Paramedian foveae nearly indistinct. Elytra 1.42-1.43 times as long as wide, 1.50-1.55 times as wide as pronotum, with a straight but narrower base; apical truncature a little more strongly sinuate, with a slightly more protruding outer angle. Formula of discal setae seems to be D1+D3, both setae being in anterior and posterior position, respectively: D1/EL=0.12-0.14, D3/EL=0.93-0.95. Yet, two of three specimens of the type series show either an unilateral setigerous pore ("D2"/ EL=0.27) situated just posterior to D1 or such an additional pore ("D2"/EL=0.33) on right elytron combined with only one anterior pore of similar position on left elytron ("D1"=0.23). Metepisternum very short, 0.9-0.97 times as long as wide.
Diagnosis. Th e present species is easily recognizable by the combination of the small, slender and wingless body, peculiar formula of discal setae, strongly reduced eyes and short antennae. Life history. Th e species is rare and has been caught in rotten wood of a log together with A. medius.

The rufipes-group
Th is monobasic group is unique fi rst due to the combination of a strong isodiametric microsculpture on the entire dorsum combined with no cross-striation on elytra and a peculiar formula of elytral discal setigerous pores: D2+D3, D2 being in anterior position (D2/EL=0.47-0.49). Eyes distinctly reduced in size and fl attened, posterior supraorbital seta situated level to about 1/3 distance between eye back margin and pronotal front margin. Wings completely reduced; metepisterna slightly longer than wide. Setigerous pores of umbilicate series uninterrupted. Last tarsomere with distal pair of ventral setae only. Antennae very short, shortest in the genus, not reaching pronotal base. Body appendages contrastingly paler than body dorsum.
Eyes rather small and fl attened, a little longer than tempora; these smoothly extending into neck in dorsal view, latter broadest among those of other congeners. Frontal foveae very shallow. 3 rd antennomere 1.2 times as long as 2 nd , 8 th 1.22 times as long as wide.
Pronotum 1.24 times as wide as long, 1.42 times as wide as head, rather strongly convex on disc, broadest before middle, distinctly sinuate before hind angles, front angles protruding; refl exed side margin rather narrow, only a little wider basad. Base medial part weakly convex backwards, much broader than lateral lobes, these slightly rounded posteriorly and increasingly oblique forward, resulting in hind angles very obtuse at apices; basal border obsolete over medial part. Mid-line shallow, hardly deeper before a superfi cial basal depression; lateral basal foveae indistinct, merging into refl exed side margin. Paramedian foveae represented by two pairs of almost indistinct, very small depressions before and behind middle.
Elytra widely oval, 1.36 times as long as wide, 1.36 times as wide as pronotum, rather strongly rounded on sides, broadest in apical third, with base very short and shoulders rounded; apical truncature hardly sinuate between distinct but rounded outer angle and a separately rounded apex of each elytron. D3/EL=0.89-0.93. Elytral intervals slightly convex, 6 th and 7 th subcarinate internally in basal half. Metepisternum very short, 0.82 times as long as wide. Material

The planicollis-group
Either body coloration uniform black or side margins of pronotum and elytra slightly paler; antennae and mouthparts red or reddish-yellow, either legs reddish-yellow or femora infuscated to dark brown except extremities. Eyes not or only slightly reduced in size and fl attened, posterior supraorbital setae situated a little to far behind the level of eye back margin. Wings completely reduced; metepisternum about as long as wide. Elytra fused along suture, oval, rather strongly rounded on sides, with strongly rounded shoulders. Discal setigerous pores on elytra two, D2+D3, D2 situated before (D2/EL=0.41-0.45) or behind (D2/EL=0.55-0.67) middle. Setigerous pores of umbilicate series uninterrupted or weakly divided into two, posthumeral and preapical, groups. Last tarsomere mostly with distal pair of setae only, otherwise proximal pair rudimentary. Refl exed side margin of pronotum moderately to very wide posteriorly; dorsum with no cilia.
Antennae long or moderately so, surpassing pronotal base. Elytral microsculpture composed of fi ne and dense transverse lines or strongly transverse meshes. Cross-striation often confi ned to elytral base only.
Th e group includes four species. Of them, two, A. refl exicollis and A. planicollis, resemble and thus might have been immediate derivatives of A. montanus and A. gracilis, respectively. Description. Body length 8.5/8.3 mm, width 3.3 mm. Black, with clypeus and labrum reddish-brown, mouthparts, antennae and legs red; femora infuscated to dark brown, except at extremities; refl exed side margins of both pronotum and elytra brownishred. Underside brown with a little paler elytral epipleura. Head and pronotum with isodiametric granulate microsculpture forming slightly transverse meshes on each side from mid-line of pronotum slightly before and behind the middle of its disc. Elytral microsculpture composed of fi ne and dense transverse lines, cross-striated sculpture moderately strong and developed throughout.
Eyes moderately convex, tempora rather smoothly extending into neck in dorsal view; posterior supraorbital seta situated slightly behind level of eye back margin. Frontal foveae shallow. Antennae long, surpassing pronotal base al least by last three joints, 3 rd antennomere 1.9 times as long as 2 nd , 8 th 3.2 times as long as wide.
Pronotum rather fl at, 1.39 times as wide as long, 1.56 times as wide as head, with front angles protruding, strongly and evenly rounded on sides, broadest about at middle, a little narrowing backwards, indistinctly sinuate before obtuse but very distinct hind angles; refl exed side margin wide, especially so basally; this, as well as lateral gutter distinctly though spa s ly punctulate. Base medial part about as wide as lateral lobes, these weakly rounded posteriorly, directed posterodistad and extending beyond medial part; basal border missing. Mid-line moderately deep, slightly deeper at a very shallow transverse basal depression; lateral basal foveae wide, rounded and fairly shallow, each as a shallow depression extending to about middle of pronotum parallel to its side margin. Paramedian foveae longitudinal, shallow, situated before middle.
Last tarsomere with two pairs of ventral setae in hind two leg pairs, but with only apical pair in fore legs. Male mesotrochanter with a weak ventral tubercle looking like a short longitudinal carina.
Penis (Figs 24,33,42) in ventral view almost straight and a little swollen in apical third, with apical lamella triangular and rounded at tip.
Diagnosis. Th is species is easily recognizable by the combination of the fairly large body, the D2+D3 formula, the absent wings, the peculiar shape and structure of the pronotum, etc.
Material Description. Body length 5.4-6.6/5.2-6.6 mm, width 2.2-2.6 mm. Dark brown to black, with clypeus and labrum reddish, mouthparts, antennae and legs reddish-yellow; refl exed side margin of pronotum hardly paler while that of elytra distinctly so, reddish. Head and pronotum dull due to a granulate microsculpture. Elytral microsculpture composed of fi ne and dense transverse lines, cross-striated sculpture moderately strong and developed throughout.
Eyes slightly reduced in size and a little fl attened, but tempora short and smoothly extending into neck in dorsal view; posterior supraorbital seta situated level to about 1/3 distance between eye back margin and pronotal front margin. Frontal foveae shallow. Antennae long, surpassing pronotal base al least by last 2.5 joints, 3 rd antennomere 1.6-1.8 times as long as 2 nd , 8 th 2.5-2.8 times as long as wide.
Pronotum very fl at, 1.30-1.41 times as wide as long, 1.40-1.47 times as wide as head, rather strongly rounded on sides, broadest before middle, rather strongly narrowing backwards and mostly conspicuously sinuate before hind angles, with front angles protruding; refl exed side margin moderately wide. Base almost straight, with medial part a little wider than lateral lobes, these somewhat increasingly oblique towards obtuse hind angles; basal border obsolete or absent medially. Mid-line rather shallow, slightly deeper at transverse basal depression, often almost extending to pronotal basal margin due to latter very weak; transverse basal depression angular forward but distinct only laterally where adjoining rather deep basal foveae; these extending forward into very shallow longitudinal depressions running parallel to pronotal side margin and sometimes traceable up to anterior third of pronotum. Paramedian foveae longitudinal and very shallow, ranging between missing to occupying middle third of pronotum length.
Last tarsomere with two pairs of ventral setae. Male mesotrochanter with a small pointed ventral tubercle.
Diagnosis. Th is species is easily recognizable by the combination of the small body, the D2+D3 formula, the absent wings, the peculiar shape and structure of the pronotum as specifi ed above.
Material. Holotype ♂ (ZISP) labelled: "Centr. Description. Body length 7.5/7.2 mm, width 3.1 mm. Black, clypeus, labrum, mouthparts, antennae and legs red; femora slightly infuscated at middle; refl exed side margin of both pronotum and elytra a little paler, reddish-brown. Head and pronotum shining in spite of a coarse isodiametric microsculpture; this transformed into slightly transverse meshes before and again behind middle of disc while weakened on vertex, neck, and over a short distance along pronotal front margin on each side from midline. Elytral microsculpture composed of fi ne and dense transverse lines, cross-striated sculpture very weak and restricted to elytral base only. Eyes slightly reduced in size and a little fl attened; posterior supraorbital seta situated slightly behind eye back margin. Frontal foveae shallow. Antennae rather long, surpassing pronotal base by last two joints, 3 rd antennomere 1.5 times as long as 2 nd , 8 th 2.3 times as long as wide.
Pronotum rather convex, especially so anteriorly, 1.54 times as wide as long and as much wider than head, with protruding front angles, slightly narrowing basad, evenly but poorly rounded on sides, broadest a little before middle, indistinctly sinuate before hind angles; side border rather widely explanate but hardly refl exed. Base almost straight, narrowly bordered, with medial part and lateral lobes subequally wide, these strongly oblique only at rounded hind angles. Mid-line rather deep throughout its  length; transverse basal depression rather sharply separated from disc convexity; basal foveae small but deep and extending forward into very wide and increasingly shallow depressions, each running parallel to side margin up to middle of pronotum length. Paramedian foveae small, rounded, deep, situated before middle. 13. Amphimenes kabakovi Fedorenko, sp. n. urn:lsid:zoobank.org:act:8DF0D22F-8C2A-4746-85E3-3539AAE60495 Fig. 16 Description. Body length 6.6/6.3 mm, width 2.75 mm. Almost black, pronotum and head dark brown, with clypeus reddish, labrum, mouthparts, antennae and legs  uniform red; refl exed side margin of elytra and pronotum behind the middle reddish. Head and pronotum with a moderately deep isodiametric microsculpture resulting in both, especially pronotum, shining, latter due chiefl y to a wide longitudinal band of a much weaker microsculpture occupying middle third of pronotum. Elytral microsculpture composed of strongly transverse but distinct meshes, cross-striated sculpture very weak and restricted to elytral base only.
Eyes rather strongly reduced in size and fl attened; posterior supraorbital seta situated level to about 1/3 distance between eye back margin and pronotal front margin. Frontal foveae shallow. Antennae surpassing pronotal base by last 1.5 joints, 3 rd antennomere 1.6 times as long as 2 nd , 8 th 2.2 times as long as wide.
Pronotum rather fl at, 1.34 times as wide as long, 1.46 as wide as head, with protruding front angles, slightly narrowing basad, moderately widely rounded on sides, broadest before middle, indistinctly sinuate before hind angles; refl exed side border narrow, a little wider basad. Base almost straight, medially unbordered, with medial part slightly broader than lateral lobes, these very strongly oblique towards almost indistinct hind angles. Mid-line moderately deep, slightly deeper where adjoining a sharp and deep basal transverse depression; basal foveae fairly deep, weakly extending forward, externally limited by a small and fl at tubercle. Paramedian foveae lengthwise, superfi cial, situated at middle. Elytra rather fl at, widely oval, 1.30 times as long as wide, 1.70 times as wide as pronotum, broadest at about middle, with shoulders strongly rounded, apical truncature slightly sinuate between rounded outer angles and elytral apices, these separate a little, due to their rounded tips. Elytral striae deep, intervals convex. D2/EL=0.42-0.44, D3/ EL=0.91-0.92. Umbilicate series of setigerous pores uninterrupted. Metepisternum 0.9 times as long as wide.
Last tarsomere only with distal pair of ventral setae. Diagnosis. Similar to the preceding species, diff ering well in the smaller body, the peculiar shape of the pronotum, as well as in the meshed microsculpture of the elytra. Material