A revision of the Oriental species of Bolitogyrus Chevrolat (Coleoptera, Staphylinidae, Staphylininae)

Abstract The Oriental species of the relictual genus Bolitogyrus are revised based on 200 specimens. An updated description of the genus is provided, including additional putative synapomorphies. Fifty valid Oriental species are diagnosed herein and the following nineteen are described as new to science: B. concavus sp. n.; B. confusus sp. n.; B. himalayicus sp. n.; B. khasiensis sp. n.; B. luteus sp. n.; B. mulayitensis sp. n.; B. nanus sp. n.; B. nokrek sp. n.; B. pecki sp. n.; B. pederseni sp. n.; B. phukhieo sp. n.; B. rougemonti sp. n.; B. sepilok sp. n.; B. schillhammeri sp. n.; B. smetanai sp. n.; B. solodovnikovi sp. n.; B. temburong sp. n.; B. tigris sp. n.; and B. tumidus sp. n. The following synonymies are proposed: Cyrtothorax borneensis Cameron, 1942, syn. n. = Cyrtothorax caesareus Bernhauer, 1915; Cyrtothorax octomaculatus Cameron, 1937 syn. n. = Quedius ornatipennis Wendeler, 1927. Quedius (Raphirus) ornatipennis is moved to Bolitogyrus as B. ornatipennis (Wendeler), comb. n. A lectotype is designated for Cyrtothorax rufipennis Cameron, 1937. Several species are named in recognition of conservation efforts to protect tropical primary forests in Asia that are important to the survival of many Bolitogyrus species. All available bionomic and distributional data for Oriental Bolitogyrus are summarized, and an identification key is provided.


Introduction
Species of the genus Bolitogyrus are rarely collected specialists of fungusy deadwood in the humid forests of the Neotropical and Oriental regions (Brunke and Solodovnikov 2014). Specimens of most species are predictably (and often solely) collected from primary or near-primary, usually protected, forests with large fallen or standing trees (Brunke and Solodovnikov 2014, Brunke pers. obs.). Thus, many species of Bolitogyrus may be at high risk of extinction without adequate designation of forest preserves. A widely disjunct distribution in the New and Old World tropics, similar to several other Staphylinini, suggests that the lineage is an ancient Eocene relict, previously widespread across the northern hemisphere when global climate was far warmer and more equable (Brunke and Solodovnikov 2013). Bolitogyrus is now classified as a member of the relictual Staphylinini subtribe Cyrtoquediina (Brunke et al. 2016), a placement supported by both morphological and molecular data (Chani-Pose et al. 2017). Other members of the subtribe include the European Astrapaeus ulmi (Rossi), Oriental Quwatanabius Smetana and Neotropical Cyrtoquedius Bernhauer, with one species in the southern Nearctic (Brunke et al. 2016). These taxa can be recognized as cyrtoquediines based on a row of coarse, epipleural punctures (Brunke et al. 2016). The monophyly of Bolitogyrus is rigorously supported and morphological characters support reciprocal monophyly of single Oriental and Neotropical lineages Solodovnikov 2014, Brunke et al. 2016).
Recently, all Neotropical species of Bolitogyrus were revised and a key was provided for their identification (Brunke and Solodovnikov 2014). Unlike the Neotropical species, which had received very little modern taxonomic attention, Oriental species of Bolitogyrus have gradually been discovered until the most recent description of seven Chinese species by Cai et al. (2015). As species concepts in Oriental Bolitogyrus have become far more complex than their original descriptions and taxonomic treatments of the genus are becoming more regionally focused (e.g., China), a broad revision of the Oriental species is greatly needed. Therefore, the present work aims to refine the morphological definition of Bolitogyrus, critically review all described Oriental species, describe previously unrecognized diversity and summarize all available data on these taxa.

Specimens
This study is based on 200 specimens that are deposited in the following collections:

BMNH
Natural History Museum, London, U.K. (R. Booth) cAss Personal collection of V. Assing, Hannover, Germany cHay Personal collection of Y. Hayashi, Kawanishi City, Japan cRou Personal collection of G. de Rougemont, London, U.K. cSch Personal collection of M. Schülke, Berlin, Germany water was applied directly to the tip of the abdomen using a fine paintbrush. As a precaution against DNA degradation, specimens examined in the present study were never subjected to high ambient humidity relaxing chambers or entirely submersed in water. This was in direct contrast to the specimens dissected for Brunke and Solodovnikov (2014), which may be less suitable for future amplification of DNA. Genitalia were cleared in a 10% potassium hydroxide solution and then washed with distilled water, then with 70% alcohol and finally placed in glycerin for observation. Genitalia were placed in glycerin filled vials for long-term storage, which were pinned with their respective specimen. Line illustrations were performed in Adobe Illustrator CS6 based on photographs. Photomontage was accomplished using a motorized Nikon SMZ25 microscope and NIS Elements BR v4.5. Photos were processed in Adobe Photoshop CS6. Distribution maps were created using QGIS 2.18 as in Brunke and Solodovnikov (2014).

Measurements and character variability
All measurements were made using a live measurement module within NIS Elements BR v4.5. Measurements were taken as listed below, but only proportional (HW/HL, PW/PL, EW/EL, ESut/PL, PW/HW) and forebody measurements were stated directly in descriptions due to a wide variability in body size. Total body length is generally not diagnostic of Bolitogyrus species and was not measured due to the contractile nature of the abdomen.

HL
Head Length, at middle, from the anterior margin of frons to the nuchal ridge. HW Head Width, the greatest width, including the eyes.

PL
Pronotum Length, at middle.

EL
Elytral Length, greatest length taken from level of the anterior most large, lateral macroseta to apex of elytra (this seta can be seen in Fig. 9 B, C and F). Its length approximates the length of the elytra not covered by the pronotum and therefore contributing to the forebody length.
Greater intraspecific variability in female tergite X and a general lack of maleassociated females made it difficult to incorporate female genitalia as fully in the Oriental species concepts compared to those of the Neotropics. Therefore, female genitalia were not illustrated though they were described where possible. Notches in the apex of female tergite X are typical of many Oriental Bolitogyrus but the size of this notch is subject to large intraspecific variation in some species. For example, the female paratypes of B. lasti Rougemont lack the notch but a small notch is present on additional female specimens examined herein. The median completion of the transverse basal line of male tergite VIII was used in previous treatments of Bolitogyrus Solodovnikov 2014, Cai et al. 2015) but significant intraspecific variability was observed in the Oriental species and so this structure is not included in descriptions.

Data resources
A specimen level dataset was made available as a Darwin Core Archive and was deposited in GBIF at http://ipt.pensoft.net/resource?r=oriental_bolitogyrus Brunke and Solodovnikov (2014) provided a redescription of Bolitogyrus and suggested that the following character states were putative synapomorphies for the genus: spineless lateral face of the hind tibia, antennomeres 1-5 without tomentose pubescence and elytra with scattered, asetose punctures. Three additional character states unique to Bolitogyrus (within Cyrtoquediina), were discovered in the course of this revision: abdominal sternite IV with basal sternal carina acutely projected at middle, single epipleural row of setae situated very close to or in contact with epipleural ridge, and epipleural ridge thickened.

Species
A revision of the Oriental Bolitogyrus resulted in the discovery of 19 new species, 2 new synonyms and the transfer of Quedius ornatipennis Wendeler to Bolitogyrus, resulting in a total of 50 valid species . The number of Bolitogyrus species worldwide now stands at 78 but can be expected to be well over one hundred with additional collecting. Male characters continue to be unknown for Bolitogyrus fukiensis (Scheerpeltz), the only Oriental species still known only from female specimens. The species were organized into eight putative species groups to facilitate comparisons between species, but it is recognized that they may not reflect monophyletic groups. Four species were not placed to any of the species groups and in general, great difficulty was experienced to form useful groupings based on multiple characters. Currently the richest country is China with 15 species but every country in the Oriental range of Bolitogyrus is still heavily under sampled. For example, the genus is entirely unknown from Sumatra and a single but widespread species is known from mainland Malaysia. At least fifteen new species represented by only females were seen in the course of this study and many others are expected, especially with more widespread use of micro-fogging of fungusy logs (see Brunke and Solodovnikov 2014 for details). 1 Elytra without red, yellow or orange coloration (e.g., Fig. 1A-B); pronotum with two fine punctures in the dorsal row, anterior angles densely and deeply punctate, and sides of disc explanate laterally ( Paramere with peg setae medially, on projected ridge (Fig. 9O); peg setae with median group extended clearly basad of marginal group (Fig. 9N); median lobe in lateral view without subapical teeth (Fig. 9L) Hind tibia entirely dark, as dark as darkened portion of femur (Fig. 3G); antennomere 6 as dark as more distal segments; paramere slightly to distinctly longer than median lobe; Yunnan province, south to northern Laos and Thailand .....7 -Hind tibia in lateral view with at least distal half distinctly lighter than darkened portion of femur (  ( In lateral view, discal elytral markings not extending halfway to epipleural margin, therefore epipleuron at most pale at humerus and apex only (as in Fig. 5F); Khasi Hills, India; aedeagus as in Fig. 17G Pale basal part of elytra composed of both yellow to orange raised marking and slightly darker non-raised area ( Fig. 6A-B Median lobe in lateral view slender and not distinctly narrowed to apex (Fig. 14K); median lobe in parameral view with acute apex (Fig. 14J)

Electus Group
The Electus Group (B. confusus, B. cyanipennis, B. electus, B. huanghaoi, B. kitawakii, B. metallicus, B. nigerrimus, B. nigropolitus and B. uncus) consists of mostly dark colored species that all possess a rounded longitudinal ridge on the prosternum (Fig. 3D) and a pronotum with two punctures in the dorsal row ( Fig. 1A-B), deeply punctate anterior angles, explanate lateral areas and a margin that is weakly expanded (Fig. 3B). A pair of lateral teeth, not found in any other Bolitogyrus species, are formed from a pair of very weakly to strongly produced carinae on the apical portion of the median lobe (Fig. 8B, H). Two reddish species have metallic green-blue elytra (Fig. 1B). As far as known, all species have an entire margin of female tergite VIII. The Electus Group was first proposed by Smetana (2000) based on the coarse punctation of the anterior angles of the pronotum. The distribution of this well-defined group is distinctly more northern than that of the others ( Fig. 19A-B), and several species occur in the warm temperate montane forests of China, a transitional zone between subtropical and cold temperate forest, where they coexist with distinctly temperate beetle groups (e.g., Lathrobium Gravenhorst (Assing 2013)). Diagnosis. Among the members of the Electus Group: head punctures clearly separated (Fig. 3E); elytra non-metallic; hind tibia entirely dark, as dark as darkened portion of femur (Fig. 3H); antennomere 6 quadrate, 7 weakly transverse (Fig. 4A); paramere slightly to distinctly longer than median lobe, with strongly attenuate apex in parameral view (Fig. 8A), in lateral view with broad lateral expansion (Fig. 8F); apex of median lobe in lateral view forming an elongate triangle (Fig. 8B); median lobe with expansion in lateral view (Fig. 8B Coloration: body black, abdominal segments sometimes slightly paler at base and apex, dorsal forebody often with faint metallic reflection; maxillary and labial palpi entirely yellowish-brown, last segment often darkened; antennomeres 1-4 or 1-5 reddish-orange with apices often darkened, 6-11 dark brown, contrasting with previous; legs bicolored: forecoxa yellow with basal fifth (males) or nearly one half dark brown (females), femur yellow and darkened apically, tibia entirely dark brown (very apex sometimes slightly paler), tarsus light brown.

Bolitogyrus electus
Head distinctly transverse, dorsal surface with moderately dense but clearly separated and asetose punctures, frons distinctly more densely and coarsely punctate.
Pronotum distinctly transverse, posterior puncture in dorsal row occasionally doubled. Elytra weakly to distinctly transverse, shorter than pronotum at middle.
Abdomen with disc of tergites III-V distinctly, VI narrowly impunctate at middle; sternites III-V with basal line projected posteriad (IV-V weakly) at middle.
Median lobe with expansion at apical third in lateral view and narrowed to acute apex, with pair of moderately-sized lateral teeth projecting ventrad (Fig. 8B, H); apical portion of median lobe in parameral view gradually narrowed to acute apex (Fig.  8H); paramere slightly to distinctly longer than median lobe, entire but with median apical suture, distinctly dilated at apical fourth and then strongly converging to attenuate apex (Fig. 8A), in lateral view with broad lateral expansion (Fig. 8F); peg setae distributed in a marginal group and a pair of divergent and elongate median clusters that are narrowly to indistinctly separated from middle, median clusters extended only slightly basad of marginal group (Fig. 8D); apical margin of male sternites VII and VIII weakly emarginate, VIII with elongate triangular asetose area medially; male sternite IX distinctly expanded at midlength, with distinct apical emargination.
Female tergite X triangular with small rounded apex, disc not characteristically flattened.
Distribution. Figure 19A. This species is distributed in the mountains of central Yunnan, China. The female paratype from Gaoligongshan may actually belong to B. uncus based on distribution. Until males are available from western Yunnan, the identity of this specimen must remain in doubt.
Bionomics. Bolitogyrus electus is found at higher elevations than its closest relatives (B. uncus, B. huanghaoi and B. confusus) and, according to more precise labels, occurs at or above 2500 m. Specimens were collected in June and July.
Comments. The identity of Bolitogyrus electus was until now rather confused in the literature (see discussion under B. confusus) and the concept herein is based on diagnostic differences consistent with the male holotype. Presently, Bolitogyrus electus cannot be separated from B. uncus unless males are dissected but it is possible that these two species are not sympatric in Yunnan Province, China. Cai et al., 2015 Figs 8C, E, G, I, 19A (map) Bolitogyrus uncus Cai et al., 2015: 472. Type locality. Longtanghe, Tengchong County, Yunnan, China. Type material. The holotype was not examined of this recently described species but the illustrations in the description (Cai et al. 2015) and additional photos provided by the senior author of that paper were studied.
Distribution. Figure 19A. Known only from one locality in western Yunnan, China.
Bionomics. This species was collected at a lower elevation (ca. 2080 m) than its closest relative, B. electus, and may regularly occur in the different forest type. The single known specimen was collected in May.
Comments. In their description of Bolitogyrus uncus, Cai et al. (2015) apparently compared it to the concept of B. electus used by Hu et al. (2011), which actually represented a different and new species (B. confusus). However, B. uncus remains a valid species based on diagnostic characters given above including the shorter apex of the median lobe and different shape of the paramere in lateral view. The differences mentioned by Cai et al. (2015) in the length of the paramere versus the median lobe (slightly longer versus approximately equal) are considered too variable based on the study of more material. Diagnosis. Among the members of the Electus Group: head punctures clearly separated (Fig. 3B); elytra non-metallic; hind tibia entirely dark, as dark as darkened portion of femur (Fig. 3H); antennomere 6 weakly transverse, 7 distinctly transverse (Fig. 4B); paramere slightly longer than median lobe, only moderately dilated and apex not attenuate (Fig. 8J); apex of median lobe in lateral view forming an elongate triangle (Fig. 8B); median lobe with expansion in lateral view (Fig. 8B); peg setae absent from only narrow strip along middle of paramere (Fig. 8K).
Distribution. Figure 19A. Known from southeastern Yunnan and northern Laos. A single female from northern Thailand may belong to this species.
Bionomics. Bolitogyrus confusus has been collected from forests in May, at elevations at or less than 2000 m and has a distinctly more southern distribution than all other members of the Electus group.
Etymology. The species epithet refers to the previous confusion of this species with B. electus and B. uncus.
Comments. This is the taxon illustrated by Hu et al. 2011 as B. electus. The authors commented that the 'apex [of the paramere] was broader' but attributed this to intraspecific variation. Additional distinguishing characters can be found under diagnosis. Diagnosis. Among the members of the Electus Group: head punctures clearly separated (Fig. 3E); elytra non-metallic; hind tibia entirely dark, as dark as darkened portion of femur (Fig. 3H); antennomere 6 weakly transverse, 7 distinctly transverse (4B); paramere slightly longer than median lobe, only slightly dilated and apex not at-tenuate ( Fig. 8M); apex of median lobe in lateral view forming a more elongate triangle (Fig. 8N); median lobe without expansion in lateral view (Fig. 8N); peg setae absent from broad oval-shaped area along middle of paramere (Fig. 8O).
Distribution. Figure 19A. Known from a single locality in western Yunnan, China. A specimen from nearby in Myanmar is tentatively identified as this species but is missing the terminal segments of the abdomen.
Bionomics. The holotype was collected at about 1600m in June.

Comments.
Bolitogyrus huanghaoi is most similar to B. confusus but they are distinctly allopatric and differ in the arrangement of peg setae of the paramere. Diagnosis. Among the members of the Electus Group: head punctures clearly separated (Fig. 8E); elytra non-metallic; hind tibia with at least distal half distinctly lighter than apex of femur (Fig. 8G); median lobe in lateral view with large expansion (Fig. 8P, arrow); paramere distinctly shorter than median lobe, distinctly dilated in apical third (Fig. 8Q); peg setae absent from narrow median area of paramere, pair of median clusters extended distinctly basad of marginal group (Fig. 8Q). Extremely similar to B. electus and differing only in the following: antennomeres I-VI paler than following segments; hind tibia brownish to brownish-yellow, paler than apical darkened area of femur, especially lateral face (Fig. 8G); head slightly less transverse; sternites III-V with basal line projected sharply posteriad at middle; median lobe in lateral view with much larger expansion at apical third (Fig. 8P), with lateral teeth smaller; paramere distinctly shorter than median lobe, slightly less dilated, apex slightly attenuate (Fig. 8Q); peg setae with pair of median clusters extended distinctly basad of marginal group (Fig. 8Q); female tergite X with acute, pointed apex.

Redescription. Measurements
Distribution. Figure 19B. Known from three localities within a small area of central Sichuan, China.
Bionomics. Collected in June-August at elevations ranging from 1730-2100 m.
Comments. Bolitogyrus nigropolitus is easily distinguished from its closest relatives by the paler antennae and legs. Type material. The type series of this recently well illustrated (Cai et al. 2015) species was not examined but the illustrations in the description (Cai et al. 2015) and additional photos provided by the senior author of that paper were studied.
Distribution. Figure 19B. Known from a single locality in northwestern Hubei, China and is the easternmost described species of the Electus group.
Bionomics. The holotype was collected in September but nothing more is known. Comments. Bolitogyrus metallicus is most similar to B. nigerrimus from Guizhou, China and can only be distinguished from it by characters on the aedeagus including the basally extended peg setae of the paramere, median ridge of the paramere and narrower apex of the median lobe in lateral view. Similar to B. electus and differing only in the following: palpi entirely pale; tibia with distal half yellowish-brown, paler than dark apical portion of femur ( Fig 3G); head slightly less transverse, dorsal surface with punctures more deeply impressed and often confluent (Fig. 3F); pronotum with sides more strongly explanate; sternite V with basal line weakly (male) or not projected posteriad (female) at middle; median lobe in lateral view with small expansion in apical fourth, with small pair of lateral teeth (Fig. 9I); paramere distinctly longer than median lobe, slightly constricted in apical fourth, apex not attenuate (Fig. 9J); peg setae in medial group not extended basad of marginal group, both groups becoming indistinguishable at apex, medial groups not divergent and situated on midline (Fig. 9K); male sternite IX not distinctly widened at midlength, markedly more elongate; female tergite X shorter, with slightly broader apex.

Bolitogyrus nigerrimus
Distribution. Figure 19B. Known from a single locality in Guizhou, China. Bionomics. The type series was collected in September at an elevation of 1450-1500 m.
Comments. Bolitogyrus nigerrimus is most similar to B. metallicus and can only be distinguished by characters on the aedeagus including the median peg setae, which are not on a ridge or extended basad, the larger lateral teeth of the paramere and larger subapical expansion of the median lobe in lateral view. The paramere was drawn in the original description (Yuan et al. 2007) with more than two macrosetae on the lateral margin when, in fact, there are only the usual two. (Zheng, 1988 Distribution. Figure 19B. Known only from the type locality in central Sichuan, China.

Bolitogyrus cyanipennis
Bionomics. A recently collected specimen was found in August at an unknown elevation.
Similar to B. electus and differing only in the following: body bicolored, head dark with moderate metallic greenish-bronze reflection, pronotum entirely pale, reddishorange, elytra dark, with bright metallic green to blue reflection, abdominal segments III-V entirely reddish-orange, segment VI reddish-orange with narrow part of apex dark, segments VII-VIII entirely dark; palpi entirely pale; antennomeres slightly but successively darker; forecoxae and tibia entirely yellowish-brown; head slightly less transverse; elytra very slightly longer than pronotum at middle; dorsal surface with punctures more deeply impressed and often confluent (Fig. 3F); pronotum with sides more strongly explanate; sternites III-V with basal line sharply (III-IV) or weakly (V) projected posteriad at middle; median lobe in lateral view without expansion, with slight expansion, with moderately-sized pair of lateral teeth (Fig. 9F); median lobe in parameral view with obtuse apex (Fig. 9H); paramere distinctly longer than median lobe, slightly more constricted in basal third (Fig. 9E); male sternite IX not distinctly widened at midlength, markedly more elongate; female tergite X shorter, with slightly broader apex.
Distribution. Figure 19B. Known from Chongqing, Sichuan, and Shaanxi provinces of China.
Bionomics. Specimens have been collected at elevations ranging from 1200-1900 m during April-June and once in August. Bolitogyrus kitawakii (B. cyanipennis probably similar) is unique within the genus for its occurrence in warm-temperate forests that experience coldest monthly mean temperatures of below freezing (-1°C) (Brunke et al. in prep).
Comments. The Shaanxi locality reported here is slightly north of the northernmost record of the genus (also for this species) (Cai et al. 2015). Bolitogyrus kitawakii cannot be externally distinguished from the allopatric B. cyanipennis but differs by the differently shaped paramere, arrangement of peg setae and shorter apex of the median lobe.

Undescribed species of the Electus Group
One female similar to B. nigerrimus was examined from Huangganshan (1800-2050 m), in the Wuyi mountains of Jiangxi province, China (FMNH). This is the only record of the Electus Group from this far east and undoubtedly represents a new species.

Caesareus Group
The Caesareus Group (B. caesareus, B. temburong, B. proximus, B. rufipennis) consists of relatively large species that occur in the Sundaland region of southeast Asia and possess the following combination of characters: prosternum without longitudinal ridge; pronotal margin greatly expanded, at its widest point, more than four lateral puncture widths wide; median lobe of aedeagus usually with a single or pair of median teeth ( Fig. 10E) but always without pairs of subapical or basal teeth that occur in members of the similar Carnifex Group; female tergite VIII lacking median notch. All members of this group, at present, also have an orange marking on the frons, which serves to distinguished them externally from members of the Carnifex Group. (Bernhauer, 1915 Cameron (1942) stated that his specimen was a female but it is actually a male with an aedeagus not appreciably different from that of the holotype of B. caesareus, and well within the range of variation seen by the present author for this taxon. Diagnostic characters given by Cameron included antennal and abdominal coloration but these are variable within B. caesareus and both extremes were observed at the same collection site (e.g., Danum valley).

Bolitogyrus caesareus
Other Coloration: body yellowish-red; head black except middle third of frons; elytra with distinct black spot margined with yellow, spot about one third the length of elytra; abdominal tergites III (entirely), IV (basally and medioapically), VI (entirely except very base), VII (entirely except for pale apical one fifth) and VIII (entirely) black; antennomere 1 yellowish except for occasionally darkened apex, 2 reddish with dark apical half, 3-7 dark brown, apical four or apical three (most common) pale yellow to almost white, apical segment asymmetrically dark on one specimen, a few specimens seen with an antennomere half dark and half pale yellow; palpi entirely yellow to dark orange, apices sometimes darkened.
Pronotum variable in shape but always distinctly transverse, convex, pronotal margin greatly expanded to variable degree. Elytra weakly to moderately transverse depending on the degree of lateral dilation, slightly shorter than pronotum at middle, in addition to usual macrosetal rows on disc, scattered punctures bearing setae, nearly all punctures setose on epipleuron of elytron; elytral disc bearing yellow margin of humeral spot raised and impunctate.
Abdomen with disc of tergites III-V distinctly, VI narrowly or not impunctate at middle; sternites III-IV with basal line distinctly, V slightly projected posteriad at middle.
Median lobe in lateral view gradually narrowed toward distinctly to slightly hooked apex, slightly constricted at apical third, without median tooth (Fig. 10B); median lobe in parameral view with apical half spoon shaped, apex slightly acute and pointed (Fig.  10A); paramere slightly to very slightly shorter than median lobe, constricted in basal third, variably dilated at about midlength, peg setae distributed in marginal group, about 2-4 peg setae wide, sometimes forming a median group in basal half (Fig. 10C); apical margin of male sternite VII with very slight emargination, male sternite VIII with shallow but distinct emargination and broad triangular, flattened, glabrous area medially; male sternite IX distinctly expanded at midlength, with distinct emargination, disc mostly glabrous except for conspicuous, divergent pair of rows of long setae.
Female tergite X elongate triangular, constricted at about midlength, with elongate raised discal area that is strongly impressed longitudinally.
Distribution. Figure 19C. Distributed on both Borneo and mainland Malaysia. No males were available from Brunei and these are only tentatively identified as this species.
Bionomics. Bolitogyrus caesareus is an inhabitant of lowland, often primary, rainforest, up to an elevation of about 550 m. Specimens were collected February to April and September-October.
Comments. No consistent differences could be found between specimens from mainland Asia and Borneo. Bernhauer (1915) speculated that this species might be termitophilous as it was sent to him along with many other specimens of species known to be termite guests. Similarly, one recent specimen was seen with a highly modified, likely inquiline, aleocharine rove beetle attached to its midleg. As in other staphylinines that are confirmed to be associated with termites (e.g., Taxiplagus), the apical antennomeres of B. caesareus and its closest relatives are asymmetrical and slightly expanded, possibly to find social insects via airborne pheromones. While this species is unlikely to be a truly integrated 'guest' of termites, it is quite possibly a predator of wood-nesting termites and may become attracted to nests that have been physically compromised. Fig 1D, Cameron (1942) stated that his specimen was a female, though it is a male. Diagnosis. Among the members of the Caesareus Group: pronotum not entirely pale; elytra without dark spot; first two visible abdominal segments with distinct darkened area (Fig. 1D); median lobe in parameral view converging to acute apex (Fig. 10D).
Measurements ♀ (n = 5). HW/HL 1.39-1.48; PW/PL 1.32-1.41; EW/ EL 1.22-1.24; ESut/PL 0.88-0.94; PW/HW 1.06-1.09; forebody length 5.9-6.5 mm. Similar to B. caesareus but differing only in the following: antennae with apical 1 or 2 segments distinctly paler, first segment entirely yellow; orange area on frons distinctly larger, reaching up to half the length of eyes; scutellum varying from entirely reddish to basal two-thirds dark brown; palpi with last segment darkened; pronotum not entirely pale and always dark medially with pale expanded margin: sometimes with a spot in each orange lateral area, sometimes pronotum with only anterior angles paler, or pronotum entirely dark; antennomeres 7-10 transverse and asymmetrical; elytra slightly shorter relative to pronotum at middle; elytral disc with small, variably-shaped, elevated and impunctate yellow spot; pronotum wider relative to head; pronotal margin distinctly more expanded; elytral disc with setose punctures only in usual rows; sternites III-V with basal line distinctly projected posteriad at middle; median lobe in lateral view slightly constricted just before apex, this part slightly deflected dorsad, with tooth basad of constriction, this tooth arising from middle of subapex, not apical carina (Fig. 10F); median lobe in parameral view sometimes with slight ridge connecting apex with tooth (Fig. 10E); paramere slightly longer than median lobe, much more strongly constricted at basal third and more strongly expanded about midlength, peg setae similar but more clearly separated into marginal and medial groups, sometimes connecting to form a pair of ovoid shapes (Fig. 10G); male sternite VII additionally with glabrous triangular area medioapically; male sternite IX with regular setation, without conspicuous rows of long setae; female tergite X triangular with acute apex, with raised, flat discal area of approximately same shape.
Distribution. Figure 19D. Endemic to the island of Borneo. The single specimen from Brunei is a female but is tentatively assigned to this species as it was collected at a lower elevation than those of the externally indistinguishable B. temburong.
Bionomics. Like the often co-collected B. caesareus, B. proximus is a species of lowland rainforests in Borneo. Several specimens indicate large trees or primary rainforest on the labels. Specimens have been collected during the months of January-February, April-August, and November, in flight intercept traps and from litter at elevations ranging from 0-200 m. Bolitogyrus proximus has been frequently collected along larger rivers, while its cryptic sister species, B. temburong occurs in lower montane forests (>400 m).
Comments. Although externally indistinguishable from B. temburong, B. proximus differs dramatically in the shape of the paramere and the median lobe in lateral view; it may also be micro-allopatric with it at a lower elevation. Diagnosis. Among the members of the Caesareus Group: pronotum not entirely pale; elytra without dark spot (Fig. 1D); first two visible abdominal segments with distinct darkened area (Fig. 1D); median lobe in parameral view dilated to blunt apex (Fig. 10H) Almost identical to Bolitogyrus proximus except: pronotum entirely black or with anterior angles orange, though variation similar to B. proximus may occur with more specimens; elytra slightly wider; elytra slightly longer proportionally than pronotum; median lobe in lateral view with apical portion thicker and flexed ventrad, median tooth situated more distally (Fig. 10I); median lobe in parameral view widened to a rounded, obtuse apex with outline bearing median tooth (Fig. 10H); paramere with more elongate and blunt apex (Fig. 10J).

Bolitogyrus temburong
Distribution. Figure 20A. Currently known only from Brunei but probably more widely distributed at medium-low elevations in Borneo.
Bionomics. Bolitogyrus temburong has been collected in February from lower montane forests at elevations ranging from 440-770m.
Etymology. The species epithet recognizes Ulu Temburong National Park in Brunei and its conservation achievements.
Comments. Bolitogyrus temburong likely represents the first of many undescribed Bolitogyrus species at medium elevations in Borneo. Based on the samples seen by the author, very limited micro-fogging of fungusy logs has been conducted on Borneo.
Type material. Cyrtothorax rufipennis Cameron, 1937 In his description of B. rufipennis, Cameron (1937) stated ambiguously that the 'Type' was in his collection. However, label data was given for 'Batoerraden' and 'Pengalengan', two different, distant Javanese volcanoes. Complicating matters, the specimen bearing a circular BMNH type label (the only one collected by Fruhstorfer) does not correspond with Cameron's morphological description (black frons, only apical antennomere paler) and is instead a female closely related to B. doesburgi (Scheerpeltz). In order to stabilize the taxonomic concept of B. rufipennis, a different, male, specimen (from "Batoerraden") that matches the original description (orange frons, apical two antennomeres paler) is here designated as a lectotype. The female from Pengalengan is excluded from the paralectotypes.
Diagnosis. Among the members of the Caesareus Group: pronotum entirely pale; elytra without dark spot; first two visible abdominal segments without distinct darkened area (Fig. 1E); median lobe with a pair of median teeth at subapex. Similar to B. caesareus but differing only in the following: antennae with apical 2 segments distinctly paler, first segment entirely yellow; palpi with last segment darkened; abdominal tergites III-V without clear dark markings; antennomeres 7-10 transverse and asymmetrical; head slightly less transverse; pronotum slightly less transverse; elytra distinctly shorter proportional to pronotum at middle; forebody slightly longer; elytral disc with small, variably-shaped, elevated and impunctate yellow spot; elytral disc with setose punctures only in usual rows; median lobe in lateral view angularly truncate with sharp apex, with pair of median teeth basad of truncate face (one visible in lateral view), this tooth arising from middle of subapex, not apical carina (Fig. 10L); median lobe in parameral view more strongly dilated subapically (Fig. 10K); paramere slightly longer than median lobe, peg setae similar but more restricted to marginal area and leaving a wider median space empty (Fig. 10 M); male sternite IX with regular setation, without conspicuous rows of long setae; female unknown.
Distribution. Figure 19D. Endemic to Java and possibly to Mt. Slamet.

Bionomics.
No additional data accompanies the specimens. Comments. Several female specimens examined are similar to B. rufipennis but may represent additional species (see 'Undescribed Species', below).

Undescribed species of the Caesareus Group.
The true diversity of the Caesareus Group appears to be very poorly known based on the number of female specimens that likely represent additional species. Three females from Borneo, consisting of 2-3 species (NMW, BMNH, cShi), are similar to but much larger than B. proximus, possess differently shaped yellow spots on the elytral disc and differ in general coloration. One female specimen, from peninsular Malaysia (600 m) and nearly identical to B. proximus, may represent another undescribed species as it differs in the shape of female tergite X. An additional female specimen from peninsular Malaysia was examined that closely resembles B. rufipennis (known only from Java) yet has an entirely dark pronotal disc. Another single female bearing only the label data 'Java' (BMNH) closely resembles the previous specimen.

Carnifex Group
The Carnifex Group (B. carnifex, B. elegantulus, B. magnimaculosus, B. nokrek, B. pederseni, B. phukhieo, B. vietnamensis) includes the largest species of the genus. The group can be recognized by the following combination of characters: pronotal margin greatly expanded, at its widest point, more than four lateral puncture widths wide (Fig. 4C); frons not contrasting in color with rest of head (Fig. 1G); median lobe with pair of basal teeth (Fig. 11A), sometimes with pair of similar, subapical teeth (Fig. 11B) This specimen in the BMNH matches all information provided by Fauvel (1878), who indicated that a single male was studied from Sharp's collection in London, and is therefore interpreted as the holotype. Another BMNH specimen, here identified as B. elegantulus, and bearing no labels, was studied. According to G. Rougemont (pers. comm.), its original labels corresponded exactly to those of the type of B. carnifex. Based on the fact that Fauvel studied a single specimen from Sharp's collection in London, and the known distribution of B. elegantulus, the true locality data for this specimen must be considered doubtful or simply, lost. However, it is possible that Mouhot did, in fact, collect this specimen during his travels (he also explored Laos) and that Sharp received it later, and prepared it in his stereotypical way.
Coloration: head entirely dark; pronotum reddish with median dark, irregular spot; elytra and scutellum reddish, disc with slightly raised yellow v-shaped marking; abdominal tergites III-V reddish with central dark marking slightly more than one-third to two-thirds the tergal width, VI dark, VII-VIII dark with paler base and apex; antennomere 1 yellow, 2-5 reddish, 6-10 dark brown, 11 yellow-brown; palpi brownish orange, apical segment darkened; legs yellowish brown, dorsal surface but not lateral face of mid-femur with darker brown (Fig. 5E) (on holotype), one nontype male with slight ventral darkening, hind femur with subapical band of dark brown; outer faces of tibia paler.
Head distinctly transverse, dorsal surface with moderately dense, clearly separated asetose punctures, frons with only scattered punctures and deep Y-shaped impression. Antennomeres 8-10 slightly transverse and asymmetrical.
Pronotum distinctly transverse, about as wide as head, convex and with very few shallow micropunctures scattered on disc, becoming more distinct on anterior angles. Elytra slightly transverse, suture distinctly shorter than pronotum at middle.
Abdomen with disc of tergites III-V distinctly impunctate; sternites III-IV with basal line distinctly, V weakly projected posteriad at middle.
Median lobe in lateral view strongly constricted in apical fourth, apical fourth deflexed ventrad, apex knob-like without distinct median tooth, with weakly formed pair of subapical teeth (Fig. 11B); median lobe with pair of basal teeth, in lateral view appearing removed from expanded ventral face (Fig. 11B), in parameral view appearing at lateral margin (Fig. 11A); median lobe in parameral view weakly expanded to apical fourth, at this level forming triangular, extremely slightly acuminate apical portion, apex acute but rounded (Fig. 11A); paramere slightly constricted in basal third, weakly dilated in apical third and narrowed evenly to apex (Fig. 11C); peg setae with marginal group, median group disorganized and connected in several places to marginal group (Fig. 11C); male sternite VIII with shallow emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct, deep emargination.
Female unknown. Distribution. Figure 20B. Known from southern Vietnam and an unknown locality in Cambodia.
Bionomics. One specimen has been collected in July.
Comments. Bolitogyrus carnifex is probably most closely related to allopatric B. pederseni and B. vietnamensis based on the wide abdominal markings and the laterally placed basal teeth of the median lobe. It can be distinguished from these two species by the weakly formed subapical teeth of the median lobe that do not form carinae. Diagnosis. Within the Carnifex Group: elytral disc entirely reddish (Fig. 1F); abdominal tergites III-V with relatively wide dark markings at middle (Fig. 5C); peg setae arranged in both marginal and medial groups (Fig. 11F); apex of median lobe knob-like in lateral view, with prominent pair of subapical teeth each situated on longitudinal ridge (Fig. 11E); basal teeth of median lobe situated laterally (Fig. 11D).
Extremely similar to B. carnifex and differing only in the following: lateral face of mid-femur with at least a faint dark band (Fig. 5D); median lobe in lateral view with prominent pair of subapical teeth each situated on longitudinal ridge forming lateral outline (Fig. 11E); median lobe in parameral view more slender, constricted weakly about midway, slightly dilated in apical third and narrowed to acuminate apex (Fig.  11D); median lobe in lateral view narrower in apical half (Fig. 11E); basal-most peg setae removed from margin (Fig. 11F).
Distribution. Figure 20B. Known from the Bolaven Plateau in southern Laos and an adjacent region of northern Cambodia.
Bionomics. The holotype was collected by pyrethrum fogging of fungusy logs in a disturbed primary rainforest (selective logging) at 1000 m during June. The paratype was collected in a malaise trap during October.
Etymology. This species is named after Jan Pedersen (ZMUC), a friend and Coleopterist, collector of the holotype, and one who shares an interest in this genus.
Comments. Bolitogyrus pederseni is most similar to allopatric B. vietnamensis from northern Vietnam but can be distinguished by the more rounded apex of the median lobe and broader paramere.
Redescription. Measurements ♂ (n = Extremely similar to B. carnifex and differing only in the following: head slightly more transverse; pronotum slightly wider relative to head; lateral face of midfemur with distinct dark band on holotype female (as in Fig. 5D) and only vague darkening on non-type male (as in Fig. 5E); median lobe in parameral view with narrower apical portion (Fig. 11G), in lateral view with subapical teeth on carina connected to apex, apex more angulate, less expanded near level of basal teeth (Fig. 11H); paramere much more slender apically, with peg setae arranged into rows (Fig. 11I).
Distribution. Figure 20B. Currently known from two localities in northern Vietnam. Bionomics. One specimen was collected in an FIT in a rainforest during May, at a relatively low (but unspecified elevation).
Comments.  stated that the type of B. vietnamensis was completely dark on the pronotum and abdomen, while the specimen is actually bicolored on both. The reddish areas of the specimen have become darkened, likely by a killing agent. Bolitogyrus vietnamensis is most similar to allopatric B. pederseni from southern Laos and northern Cambodia but can be distinguished by the differently shaped apex of the median lobe and narrower paramere. Diagnosis. Within the Carnifex Group: elytral disc entirely reddish (Fig. 1F); abdominal tergites III-V with relatively narrow dark markings at middle (Fig. 5B); peg setae arranged in both marginal and medial groups (Fig. 11L); basal teeth of median lobe placed medially in parameral view (Fig. 11J); apex of median lobe in parameral view evenly narrowed to apex (Fig. 11J).
Extremely similar to B. carnifex and differing only in the following: dark medial area on pronotum varying from similar to B. carnifex to distinctly larger; lateral face of midfemur with distinct dark band (Fig. 5D); pronotum slightly wider relative to head; median lobe in parameral view almost evenly converging to smaller apex (Fig. 11J), in lateral view, slightly more strongly constricted after basal tooth, which is distinct and appearing at ventral face (Fig. 11K); apex of median lobe in lateral view with median tooth arising from carina, apical portion only slightly deflexed ventrad (Fig. 11K); median lobe in parameral view with apical portion evenly converging to narrower apex, without pair of subapical teeth, basal teeth appearing medially (Fig. 11J); paramere with narrower and more elongate apical portion, basal constriction narrower (Fig. 11L); peg setae with marginal and medial groups more approximate and linear (Fig. 11L); female tergite VIII with narrow and deep emargination; female tergite X with obtuse but pointed apex, disc with pair of raised carinae in apical half, carinae not forming lateral margins of disc.
Distribution. Figure 20B. Distributed in southern Yunnan, China and northern Laos. Bionomics. Specimens have been collected in January, April and May at elevations ranging from 810-1500 m.
Comments. Bolitogyrus elegantulus is most similar to allopatric B. phukhieo from central Thailand but can be distinguished by the evenly converging apex of the median lobe in parameral view and the differently shaped paramere. Diagnosis. Within the Carnifex Group: elytral disc entirely reddish (Fig. 1F); abdominal tergites III-V with relatively narrow dark markings at middle (Fig. 5B); peg setae arranged in both marginal and medial groups (Fig. 11O); antennomeres 8-10 quadrate; median lobe in parameral view with basal pair of teeth placed medially (Fig.  11M); apex of median lobe in parameral view acuminate (Fig. 11M).
Extremely similar to B. carnifex and differing only in the following: body with paler areas lighter, more orange-yellow; pronotum with smaller spot medially, with two lateral spots; abdominal tergites with narrower central dark markings, about one quarter of the tergal width; antennomere 10 slightly paler than 9; antennomeres 8-10 quadrate; pronotum wider than head; body smaller (based on single specimen); median lobe in lateral view evenly narrowed to smaller apex, apical portion only weakly flexed ventrad, apex with distinct median tooth arising from carina, basal teeth prominent and appearing near ventral face (Fig. 11N); median lobe in parameral view with apical portion more strongly acuminate, apex narrower and pointed, basal teeth located medially (Fig. 11M); paramere less strongly dilated at apical third, apical portion less strongly converging to truncate apex (Fig. 11O); peg setae in medial group larger than those of marginal group, medial group mostly at expanded area of paramere (Fig. 11O).
Distribution. Figure 20B. Bolitogyrus phukhieo is probably endemic to central Thailand.
Bionomics. The holotype was collected in a pitfall trap in January at an elevation of 1000 m.
Etymology. In recognition of Phu Khieo Wildlife Sanctuary, which encompasses the type locality: a remarkable bowl-like plateau raised out of the surrounding lowland landscape to approximately 800-1000 m. The sustainable conservation of Phu Khieo is the subject of a collaborative project between Thailand and the European Union.
Comments. Bolitogyrus phukhieo is most similar to allopatric B. elegantulus from northern Laos and southern Yunnan, China but can be distinguished by the acuminate apex of the median lobe in parameral view and the differently shaped paramere. Type material. The type series of this recently described, and well-illustrated species was not examined (Cai et al. 2015).

Bolitogyrus magnimaculosus
Diagnosis. Within the Carnifex Group: elytral disc entirely reddish (Fig. 1F); abdominal tergites III-V with relatively narrow dark markings at middle (Fig. 5B); peg setae arranged in single arcuate group, removed basally from margin (Fig. 12C). Bolitogyrus magnimaculosus is the only species of the Carnifex Group known from Hainan Island, China.
Distribution. Figure 20B. Likely endemic to Hainan Island, China. Bionomics. This species has been collected at elevations ranging from 525-978 m, in November and December. One specimen was collected by 'beating the shrubs' (Cai et al. 2015) and was probably dispersing to a suitable microhabitat.
Comments. Bolitogyrus magnimaculosus is easily identified by geography alone but is also the only species known with both subapical teeth and proximally placed basal teeth on the median lobe. Extremely similar to B. carnifex and differing only in the following: apical antennomere only slightly paler than previous; pronotum almost entirely covered by dark marking; elytral darkened basally; abdominal segments III-IV almost entirely dark; dorsal face of tibia darkened; midfemur with distinct dark subapical marking; median lobe in lateral view with small, acute apex, slightly deflexed dorsal with flat ventral face instead of tooth, basal teeth present and appearing removed from ventral face, subapical teeth absent (Fig. 12E); median lobe in parameral view slightly constricted at midlength, apical portion strongly acuminate to acute and narrow apex bearing median carina (Fig. 12D); paramere in lateral view strongly projecting beyond and deflexed over apex of median lobe (Fig. 12G); paramere with distinctly narrower apical third, median group of peg setae extending basad of thin marginal group (Fig. 12F); female tergite VIII with narrow and deep emargination; female tergite X with domelike expansion in apical half, without distinct carinae.

Bolitogyrus nokrek
Distribution. Figure 20C. Likely endemic to the Garo Hills, Meghalaya, India. Presently the westernmost species of the Carnifex Group.
Bionomics. Bolitogyrus nokrek has been collected at 1400 m in April and May.
Etymology. This species is named in recognition of the Nokrek UNESCO Biosphere Reserve in the Western Garo Hills of Meghalaya, India, where all known specimens were collected.
Comments. Two females, (Khasi Hills Meghalaya (IRSNB)), and northern Kachin State, Myanmar (SEMC)) may belong to this or additional new species. They are excluded from the type series.

Lasti Group
The members of the Lasti Group share the following character states: a deeply bilobed paramere, unique among Oriental Bolitogyrus; expansion of pronotal margin reduced; apex of median lobe deflexed dorsad. Thus far, the group is restricted to southern India. Diagnosis. This species can be distinguished by the following character states: head entirely dark; elytral disc dark with pale markings not extending onto epipleuron (Fig. 5F); pronotal margin narrow, almost without expansion (Fig. 4G). Coloration: head, pronotum and abdomen entirely dark; elytra with pale yellow, raised markings, inner marking oval shaped and larger than outer circular marking; antennomeres 1-3 dark brown, 4-5 reddish, 6-10 dark brown, 11 distinctly paler, light brown to yellowish; palpi dark brown, apical segment paler; legs yellow, forecoxae dark brown, femur with dark band in apical half, tibia entirely dark with ventral face sometimes paler.
Pronotum distinctly (males) to slightly transverse, about as wide as head, with shallow micropunctures scattered on disc, becoming more distinct on anterior angles. Elytra slightly transverse, suture slightly to distinctly shorter than pronotum at middle.
Abdomen with disc of tergites III-VI distinctly and broadly impunctate; sternites III-IV with basal line distinctly projected posteriad at middle.
Median lobe in lateral view with apical portion projected ventrad, apex deflexed dorsad (Fig. 12I); median lobe in parameral view with basal teeth appearing at lateral margins (Fig. 12H); paramere shorter than median lobe, bilobed, lobes narrowly separated and slightly convergent (Fig. 12J); peg setae occurring in long group on each lobe from apex to just apicad of emargination (Fig. 12J); male sternite VIII with extremely shallow emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct U-shaped emargination.
Female with tergite VIII entire (female paratype) to emarginate, emargination minute to small; tergite X elongate shield-shaped, with broadly rounded apex, disc slightly raised and without depressions or strong ridges.
Distribution. Figure 20D. Endemic to the Western Ghats of India. Bionomics. Bolitogyrus lasti has been collected at 1000-1200 m during January, May, September and December.
Comments. Bolitogyrus lasti is most similar externally to B. ornatipennis from Java but can be distinguished by the narrow pronotal expansion and more circular inner pale elytral spot.

Diagnosis.
Bolitogyrus tigris is easily recognized by a combination of the minutely expanded pronotal margin (Fig. 4G), orange head, the bicolored abdominal tergites IV-V, and orange and black marked elytra (Fig. 1I).
Coloration: body orange to reddish-orange (darkened paratype); head orange with central darkened area larger in female; disc of pronotum orange with central darkened area, a pair of dark spots laterally, a darkened areas along apex and base; elytra orange to reddish-orange (darkened paratype), with darkened area around scutellum; abdominal tergite III mostly dark with lateroapical areas orange, IV-V orange, dark basally and in narrow median stripe, VI entirely dark on disc, VII-VIII orange; antennomeres 1-5 brownish orange, 6-10 dark brown, 11 slightly paler than previous, lighter brown; palpi brownish orange; legs brownish orange, with dorsal and lateral surfaces of mid and hind femur darkened, outer faces of tibia darker.
Pronotum distinctly transverse, about as wide as head, convex and with shallow micropunctures scattered on disc, becoming more distinct on anterior angles. Elytra slightly transverse, suture slightly shorter than pronotum at middle; disc of elytron with slightly raised yellow v-shaped marking.
Abdomen with disc of tergites III-V distinctly impunctate; sternites III-IV with basal line distinctly projected posteriad at middle.
Median lobe in lateral view with apical portion projected ventrad, apex deflexed dorsad, with pair of basal teeth at level of apical fourth (Fig. 12L); median lobe in parameral view slightly dilated to apical fourth, spoon-shaped (Fig. 12K); paramere distinctly shorter than median lobe, distinctly bilobed, each lobe with pointed apex, constricted just basad of v-shaped median emargination (Fig. 12M); peg setae of each lobe arranged in marginal group and medial group, groups joined basally to form a ring (Fig. 12M); male sternite VIII with extremely shallow emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct emargination.
Female with tergite VIII entire in single specimen studied, tergite X elongate triangular, with acute apex, raised disc of similar shape with broad median depression.
Distribution. Figure 20D. Known only from the Cardamom Hills in the Western Ghats of India.
Bionomics. Bolitogyrus tigris has been collected at 1000 m during October and December.
Etymology. This taxon shares its specific epithet with the Bengal Tiger (Panthera tigris tigris (L.)) in recognition of its orange and black appearance, shared distribution, and India's network of preserved forest habitats in the Anaimalai, Palni and Cardamom Hills regions of the Western Ghats. Habitat-focused conservation preserves populations of popular megafauna but also predaceous beetles like Bolitogyrus tigris, a 'tiger' in its own right Comments. Bolitogyrus tigris is easily recognized by coloration alone.

Luteus Group
The members of the Luteus Group share the following character states: head and pronotum mostly orange to reddish-orange; disc of elytra with yellow, raised marking elongate and transverse (Fig. 4H); median lobe in lateral view with distinct apical portion that is expanded (Fig. 13C, 13F). Both members are lowland rainforest species and known only from the holotypes. Diagnosis. This species is easily distinguished by the combination of the orange head and pronotum, transverse and raised yellow marking on the elytra (Fig. 4H-I) and the distinctly paler antennomere XI.
Coloration: body orange, head with small medial darkened spot, pronotum with single median and pair of lateral dark spots, elytra each with large lateral and triangular marking that extends onto epipleuron only apically, elytra each with transverse and raised yellow marking (Fig. 4H); abdominal tergites VI with median dark spot, VII almost entirely dark with apex and base paler; antennomere 1 yellow, 2 -5 reddish, 6-10 dark brown, 11 paler, yellow; palpi yellow with apical segment darker; legs yellow with small ventroapical part of femur darker.
Pronotum distinctly transverse, about as wide as head, with very few shallow micropunctures scattered on disc, becoming more distinct on anterior angles. Elytra slightly transverse, suture slightly shorter than pronotum at middle; disc of elytron with slightly raised yellow transverse marking.
Abdomen with disc of tergites III-IV distinctly, V narrowly impunctate.
Median lobe in lateral view with apical portion sinuate due to expansion, projected ventrally, with large median tooth arising from median carina (Fig. 13A-B); median lobe in parameral view subparallel-sided, apical portion slightly acuminate, without basal teeth (Fig. 13C); paramere entire with median suture, distinctly longer than median lobe, with long and narrow apical portion, peg setae arranged in thin marginal row that extends basad to level of suture, thin median row extending basad of marginal row and slightly thicker at base (Fig. 13D); male sternite VIII with extremely shallow emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct emargination.
Female unknown. Distribution. Figure 21A. Known only from the type locality in western Thailand. Etymology. The specific epithet refers to the warm, reddish-orange body coloration.
Bionomics. The holotype was collected in March along the banks of a large river with several other species of Bolitogyrus and many other staphylinids (G. Rougemont, pers. comm.), which may have been flooded out from the forest with heavy rains.
Comments. Bolitogyrus luteus can be recognized by coloration alone. Diagnosis. This species is easily distinguished by the combination of the orange head and pronotum, transverse and raised yellow marking on the elytra (as in Figs 2A, 4H) and the abdominal tergites with deeply impressed and elongate punctures (Fig. 5A).
Similar to B. luteus and differing only in the following: body with pale areas darker, dark reddish; abdominal tergites I-III with broad medial dark markings; palpi slightly darker; forecoxa with small dark marking at midlength; femur with dark subapical band, apex of hind tibia dark; antennomeres 1-3 orange with slightly darkened apices, 4-8 dark brown, 9 light brown, 10-11 light yellow; pronotum distinctly more elongate and strongly convex; pronotum relatively narrower than head; forebody length smaller; abdominal tergites III-VI with deeply impressed and elongate punctures in basal impressions; median lobe in lateral view with much larger expansion in lateral view, with pair of broad basal teeth (Fig. 13F); median lobe in parameral view with basal teeth appearing medially, apical portion shorter and only slightly acumi-nate (Fig. 13E); paramere shorter than median lobe, narrower with smaller expansion, peg setae in broad single row reaching midlength, distant from midline (Fig. 13G).
Distribution. Figure 19C. Known only from the type locality in northeastern Borneo but probably more widely distributed in remnant lowland forests.
Bionomics. Bolitogyrus sepilok was collected from fungi on a log in February at a lowland elevation.
Etymology. In recognition of the Kabili-Sepilok Forest Preserve, which adjoins the type locality and preserves a significant remnant of virgin lowland Dipterocarp forest in northern Borneo.
Comments. Bolitogyrus sepilok can be recognized by its distinct habitus alone.

Pictus Group
The members of the Pictus Group (B. concavus, B. pictus, B. profundus, B. rougemonti, B. schillhammeri) share a characteristic subbasal expansion of the paramere in lateral view (Fig. 15B, arrow). All species also possess a basal pair of teeth on the median lobe that are placed laterally (minute in B. concavus). The species are identical externally, though nearly all are allopatric. The three species that are known from multiple collecting events were found to exhibit color dimorphism, with bicolored and dark morphs. The holotype of this species is a female and this initially caused doubt about the identity of B. pictus and the externally identical and sympatric B. profundus. Yuan et al. (2007) associated male characters with B. pictus based on a single male collected from near the type locality. However, it was unknown at the time that externally identical species of the Pictus Group exist in sympatry, which is rare in Bolitogyrus. To complicate matters further, Cai et al. (2015) described B. profundus based on a single male from the same locality as the single male identified as B. pictus by Yuan et al. (2007).
With the dissection of females co-collected with both B. pictus and B. profundus, it became possible to recognize the two taxa based on the apex of female tergite X. Luckily, these taxa are not each other's closest relatives, as the shape of female tergite X in B. schillhammeri is indistinguishable from B. pictus. Based on these associations, the male characters described by Yuan et al. (2007) happen to be correctly associated with B. pictus and do not refer to yet another species.
Other Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape (Fig. 2B, 5G), medial and lateral markings of different sizes and never entirely fused (Fig. 5G); apex of median lobe hooked in lateral view, broad and short in parameral view (Fig. 14B); paramere with short apical portion and at most slightly longer than median lobe (Fig. 14A). Coloration: color dimorphic, dark morph with dark pronotum and dark abdomen; bicolored morph with red pronotum and abdomen with tergites III-V entirely and base of VI reddish. Head entirely dark; elytra with raised median marking ovalshaped and larger than raised lateral marking, markings always connected, pale area extended onto epipleuron, epipleuron varying from pale at midlength to nearly entirely pale; scutellum dark; antennomere 1 yellow with darkened apex, 2-5 reddish, 6-10 dark brown, 11 either dark brown or vaguely paler; palpi yellow with apical segment slightly darker; legs yellow, fore and midfemur with small ventroapical dark marking, hind femur with small apical band.
Pronotum distinctly transverse, about as wide as head, with a few shallow micropunctures on disc, becoming more distinct on anterior angles. Elytra slightly transverse, suture slightly shorter than pronotum at middle.
Abdomen with disc of tergites III-VI distinctly impunctate medially, some specimens with VI only narrowly impunctate; sternites III-IV with basal line distinctly projected posteriad at middle.
Median lobe in lateral view sinuate, apex pointed and sharply deflexed ventrad, basal teeth appearing at ventral face (Fig. 14B); median lobe in parameral view slightly dilated to wide and short apex, basal teeth appearing at lateral margins (Fig. 14A); paramere as long as or slightly longer than median lobe, entire but with median suture that extends to about widest point, with apical portion deflected slightly dorsad (Fig. 14A); peg setae arranged in marginal and medial groups, marginal group extending to basal third of median suture, medial group as loose row that extends basad of marginal group (Fig.  14C); male sternite VII with slight emargination and broad impunctate area medially; male sternite VIII with distinct emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct emargination.
Female tergite VIII with median emargination deep and elongate; female tergite X shield-shaped, disc with distinct and entirely rounded dorsal expansion in apical half, apex truncate with narrow and rounded median projection.
Distribution. Figure 21A. Bolitogyrus pictus is known from southern Yunnan, China, and northern Laos. It probably also occurs in northern Thailand.
Bionomics. This species has been collected in March, May and July, at elevations ranging from 600-1500 m.
Comments. Bolitogyrus pictus is most similar to allopatric B. schillhammeri (Myanmar) but differs by the broader apex of the paramere and hooked apex of the median lobe in lateral view. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of differ-ent sizes and never entirely fused (Fig. 2B, 5G; apex of median lobe not hooked or flattened in lateral view, apical portion with flat ventral face in lateral view (Fig. 14E), broad and short in parameral view (Fig. 14D); paramere with long and elongate apical portion, slightly longer than median lobe (Fig. 14D) Extremely similar to B. pictus and differing only in the following: median lobe in lateral view with apex not hooked, apical portion with ventral face straight (Fig. 14E); median lobe in parameral view with apical portion slightly narrower (Fig. 14D); apical portion of paramere distinctly more elongate and narrower (Fig. 14F).

Bolitogyrus schillhammeri
Distribution. Figure 21B. Bolitogyrus schillhammeri is known from three localities in the Shan Hills (incl. Karen hills) of Myanmar.
Bionomics. This species has been collected in March, May and June at 900-1320 m. Specimens have been collected from rotten wood and from within fungi.
Etymology. The species is named in honor of Harald (Harry) Schillhammer (NMW), the collector of many specimens of the type series, and a wonderful friend and field companion. Harry's adventurous spirit and broad knowledge have led to many shared 'eureka' moments for staphylinid systematics.
Comments. Bolitogyrus schillhammeri is most similar to B. pictus but can be distinguished by the narrower apex of the paramere and the non-hooked apex of the median lobe in lateral view. Paratype (♂, cRou): same data as holotype except: AJB0000415. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of different sizes and never entirely fused (Fig. 6C); apex of median lobe flattened in lateral view (Fig. 14H), broad and short in parameral view (Fig. 14G). Extremely similar to B. pictus and differing only in the following: only dark specimens known; head, pronotum and abdomen entirely dark; antennomere dark brown; median lobe in lateral view strongly flattened in apical portion, dilated subapically, basal teeth appearing removed from lateral margin (Fig. 14H); median lobe in parameral view with apical portion slightly narrower (Fig. 14G); paramere with shorter and distinctly acuminate apical portion (Fig. 14I), in lateral view strongly deflexed dorsad over apex of median lobe; female unknown.

Bolitogyrus rougemonti
Distribution. Figure 21B. Known only from the type locality in western Thailand. Bionomics. The type series was collected in March along the banks of a large river, with many other beetles including Bolitogyrus (G. Rougemont, pers. comm.) that may have washed out from preferred deadwood microhabitats.
Etymology. This species is named in honor of Mr. Guillaume de Rougemont (United Kingdom), the sole collector of this and many other Oriental Bolitogyrus species. Material from his personal collection has greatly increased the comprehensiveness of this monograph.
Comments. At present, B. rougemonti is the only lowland member of the Pictus Group. This species is distinctive for its expansion of the median lobe in lateral view and shortened apex of the paramere. Type material. The type specimen of this recently described, and well-illustrated species was not examined (Cai et al. 2015) but the illustrations in the description (Cai et al. 2015) and additional photos provided by the senior author of that paper were studied. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of different sizes and never entirely fused (Fig. 5G); apical portion of median lobe in lateral view not projecting ventrad or dorsad, not flattened, apex angulate and not hooked (Fig.  14K); apical portion in parameral view narrow and acuminate (Fig. 14J) Extremely similar to B. pictus (including color dimorphism) and differing only in the following: median lobe in lateral view with apical portion more or less straight, apex angulate, basal teeth appearing removed from ventral face (Fig. 14K); median lobe in parameral view with apical portion distinctly longer and acuminate, basal teeth appearing laterally (Fig. 14J); paramere slightly shorter than median lobe, with apical portion more strongly acuminate, apex much narrower (Fig. 14L); female tergite X with apex not projecting at middle, apex widely acute and not truncate.

Bolitogyrus profundus
Distribution. Figure 21B. Bolitogyrus profundus is known from southern Yunnan, China, northern Laos, and central and northern Thailand.
Bionomics. Bolitogyrus profundus has been collected in May and October at elevations ranging from 750-1500 m.
Comments. The acute apex of the median lobe was observed to be longer in specimens south of the type locality in Yunnan, China. This is attributed to intraspecific variation. Bolitogyrus profundus is similar to allopatric B. concavus (Meghalaya, India) but can be distinguished by the straight apex of the median lobe and the distinct rows of peg setae on the paramere.
Bolitogyrus concavus Brunke, sp. n. Fig. 15A Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of different sizes and never entirely fused (Fig. 5G); apical portion of median lobe in lateral view flattened and concave ventrad (Fig. 15B), in parameral view narrow and acuminate (Fig. 15A).
Extremely similar to B. pictus and differing only in the following: only dark specimen known; median lobe in lateral view with apical portion thin, and concave ventrad, apex deflexed dorsad, basal teeth extremely weakly formed (Fig. 15B); median lobe in parameral view with apical portion distinctly longer and acuminate (Fig. 15A); paramere only slightly expanded about midway (Fig. 15A); peg setae arranged in marginal group and as several scattered setae medially (Fig. 15C). Female unknown.
Distribution. Figure 21C. Known only from the type locality in the Garo Hills, Meghalaya, India.
Bionomics. The holotype was collected at approximately 1100 m in May. Etymology. The species epithet refers to the apex of the median lobe, which is uniquely thin and concave in lateral view.
Comments. Bolitogyrus concavus is most similar to allopatric B. profundus (China, Laos, Thailand) but is easily distinguished by the shape of the median lobe and the peg setae of the paramere, which are arranged mostly along the margin.

Vulneratus Group
In species of the Vulneratus Group (B. vulneratus, B. flavus, B. rufomaculatus, B. depressus, B. fukiensis, B. tumidus and B. taiwanensis), the median lobe in lateral view is projected ventrad and hooked apically. Unlike species of the Loculus Group (Fig. 16F), the apex of the median lobe is not carinate in the Vulneratus Group (Fig. 13I, M). Most species (except lowland species B. flavus and B. vulneratus) also have a distinctive elongate projection at the middle of the apex of female tergite X. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings not entire-ly fused (Fig. 5G); apex of hind femur with only ventral half darkened (as in Fig. 2C); antennomere 7 distinctly transverse (Fig. 6F); median lobe in lateral view ventrally produced and hooked, without basal teeth (Fig. 13J).
Coloration: head, pronotum and abdomen entirely dark; elytra with raised median marking oval-shaped and larger than raised lateral marking, markings connected, pale area extended onto epipleuron, epipleuron pale, pale area varying from near humerus to basal half; scutellum dark; antennomere 1 yellow with darkened apex, 2-5 reddish, 6-10 dark brown, 11 either dark brown or vaguely paler; palpi yellow with apical segment slightly darker; legs yellow, hind femur with small ventroapical dark marking.
Pronotum distinctly transverse, slightly wider than head, center of disc almost entirely without micropunctures, micropunctures becoming more distinct on anterior angles. Elytra slightly transverse, suture distinctly shorter than pronotum at middle.
Abdomen with disc of tergites III-VI distinctly impunctate medially, VI slightly more narrowly than others.
Median lobe in lateral view projected ventrad, with hooked apex, without basal teeth (Fig. 13J); median lobe in parameral view slender, with very slight expansion at about apical two-thirds, apical portion evenly converging to acute apex (Fig. 13I); paramere about as long as median lobe, slender, moderately expanded in apical twothirds, apical portion broad and truncate (Fig. 13H), peg setae arranged in marginal group with some scattered setae mediad (Fig. 13K); male sternite VIII with distinct but shallow emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct emargination.
Female tergite VIII with median emargination broad triangular, moderately deep; female tergite X elongate shield-shaped, with the disc evenly convex and lacking distinct raised areas, apex acuminate with apex projected.
Distribution. Figure 22A. Bolitogyrus vulneratus is known only from low hills of central and southern Vietnam.
Bionomics. One specimen was collected in March at 100 m. Comments. Bolitogyrus vulneratus has been confused with many small species in previous literature and in collections because, until now, only the female holotype was available. Study of the male genitalia reveals that this species is related to another lowland species, B. flavus, but can be distinguished by the presence of medial and lateral pale areas of the elytra. Bolitogyrus vulneratus is also similar externally to B. hainanensis but can be distinguished based on the simply hooked apex of the median lobe, absence of a clear median group of peg setae and a non-bilobed paramere. Two females (cShu) from southern Vietnam lowlands (60 km NE of Hoa Chi Min city) were studied that may represent an additional, undescribed species close to B. vulneratus. The elytral markings are longer and female tergite X has a distinct, raised area on the disc. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, base of elytra with broad pale area composed entirely of pale, raised yellow marking extending onto epipleuron (Fig.  2C, 6C); elytra with punctures along sutural area (Fig. 6C); paramere not constricted apically (Fig. 13L); female tergite VIII with wide triangular emargination (Fig. 7B).
Similar to B. vulneratus and differing only in the following: elytra with broad basal area composed entirely of raised yellow marking, pale area variable, as large spot extending to apical two-thirds (Fig. 6C) to extended to almost entire disc and leaving only apical angles dark (Fig. 2C); dark markings on femoral apices slightly larger on some specimens but never including dorsal face; head less transverse; antennomeres 7-10 distinctly transverse (Fig. 6F); pronotum more transverse; abdominal tergite VI not or only narrowly impunctate at middle; median lobe in lateral view with basal teeth formed as wide, toothed ridge (Fig. 13N); median lobe in parameral view with basal teeth barely visible, apical portion elongate and expanded, then suddenly constricted to acuminate and narrow apex (Fig. 13M); paramere elongate spoon-shaped (Fig. 13L), peg setae arranged in wide marginal group, convergent basally (Fig. 13O).
Distribution. Figure 22A. Bolitogyrus flavus is widely distributed over the mainland of the southeast Oriental region.
Bionomics. As far as known, B. flavus is a lowland to lower montane species and does not occur above 1000 m. Specimens have been collected in all months except February and September. Bolitogyrus flavus has been collected from fungi and rotten wood.
Comments. Bolitogyrus flavus is the most commonly collected species of the genus in the Oriental region. Several single females could extend its range even further but may actually represent other related species.
Type material. Cyrtothorax rufomaculatus Shibata, 1979. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of different sizes and never entirely fused (Fig. 5G); median lobe in lateral view projected ventrad, with hooked apex and without distinct expansion, basal teeth appearing at or near ventral face (Fig. 15E); median lobe in parameral view with apex acuminate (Fig. 15D); paramere slightly to distinctly longer than median lobe and at most, as wide as median lobe in parameral view (Fig. 15D-E).
Redescription Similar to B. vulneratus and differing only in the following: females sometimes with small basal area of forecoxae dark; head slightly less transverse, frontal impression more weakly impressed; antennomeres less transverse, 7 slightly, 8-10 distinctly transverse, 10 asymmetrical and longer than 9; pronotum more transverse; suture longer relative to pronotum at middle; forebody slightly longer; pronotal disc slightly more micropunctate; median lobe in lateral view with basal teeth appearing at ventral face (Fig. 15E); median lobe in parameral view widened in apical fourth and then strongly narrowed to acuminate apex, basal teeth appearing mediad of lateral margin (Fig. 15D); paramere at widest point, no wider than median lobe, slightly to distinctly longer than median lobe, with longer, slightly to distinctly acuminate apical portion (Fig. 15D); peg setae arranged in clear medial and marginal groups, medial group extended basad of marginal group (Fig. 15G); male sternite VIII emargination very slight; female tergite VIII with narrower emargination, varying from moderately deep to deep U-shaped; female tergite X with apical projection raised and distinctly longer than wide.
Distribution. Figure 21D. Bolitogyrus rufomaculatus is distributed broadly in Taiwan, in mountainous areas on the western half of the island.
Bionomics. Specimens have been collected in January, March-May and July, at elevations ranging from 400-2000 m. Some specimens have been sifted from litter.
Comments. Bolitogyrus rufomaculatus may be allopatric with B. taiwanensis, the only other species of the genus on Taiwan. These two species are easily distinguished using the color of the elytra and are not each other's closest relatives. Bolitogyrus rufomaculatus is most similar to allopatric B. depressus (mainland China) but lacks the expansion of the median lobe in lateral view, has a basal tooth on the median lobe, and the paramere is longer than the median lobe. Cai et al., 2015 Figs 15F, 21D (map) Bolitogyrus depressus Cai et al., 2015: 454. Type locality. Nanling National Forest Park, Ruyuan County, Guangdong, China.

Bolitogyrus depressus
Type material. The type series of this recently described, and well-illustrated species was not examined (Cai et al. 2015).
Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of different sizes and never entirely fused (Fig. 5G); median lobe in lateral view projected ventrad, with hooked apex, basal teeth absent (Fig. 15F); median lobe in parameral view with apex acuminate (Fig. 15D); paramere shorter than median lobe (Fig. 15F) and at widest point slightly wider than median lobe in parameral view.
Distribution. Figure 21D. Known only from the type locality in Guangdong, China.
Bionomics. The holotype was collected in July. Comments. Although Cai et al. 2015 did not directly compare B. depressus to B. rufomaculatus, they are extremely similar. Unlike B. rufomaculatus, Bolitogyrus depressus does not bear basal teeth on the median lobe, has a large expansion on the median lobe in lateral view, and the paramere is shorter than the median lobe. One female specimen from low elevation (600 m) from Guizhou, China was examined (cShi) that could be this species.  1. -31.5.20111. -31.5. , 20°12'N 104°01E, 15001. -31.5. -1900  Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of different sizes and never entirely fused (Fig. 5G); median lobe in lateral view projected ventrad, with hooked apex, basal teeth appearing distant from strongly expanded ventral face (Fig. 15K); median lobe in parameral view with apex acuminate (Fig. 15J).
Similar to B. vulneratus and differing only in the following: elytral markings only weakly connected or separate in specimens available; head less transverse; antennomeres overall less transverse, antennomere 6 slightly, 7-10 distinctly transverse, 8-10 asymmetrical; forebody slightly longer; median lobe in lateral view with ventral face expanded subapically, apical portion projected ventrad, strongly constricted and hooked apically, basal teeth appearing distant from ventral face (Fig. 15K); median lobe in parameral view with apical portion expanded and subparallel, constricted to short, acuminate and narrow apex, basal teeth appearing mediad of lateral margins (Fig. 15J); paramere about as long as median lobe, narrower with longer apical portion (Fig. 15J); peg setae more numerous and densely arranged into discernable marginal and medial groups, marginal group broader (Fig. 15L); male sternite VIII emargination very slight. Female unknown.
Distribution. Figure 21D. Known only from the type locality on Mt. Phu Pan in northern Laos.
Bionomics. Specimens were collected at an elevational range of 1500-1900 m in May and June.
Etymology. The specific epithet refers to the swollen, preapical portion of the median lobe.

Bolitogyrus taiwanensis
Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, with broadly pale basal area composed of yellow raised marking and slightly darker non-raised area; antennomere 7 distinctly transverse; female tergite X with disc raised medioapically.
Similar to B. vulneratus and differing only in the following: elytra with broad basal area composed of raised yellow marking and non-raised, slightly darker area (Fig. 6B); middle femur with small ventroapical area darkened; hind femur with dark apical marking slightly larger; head less transverse; elytral suture relatively longer than pronotum at middle; forebody slightly longer; male unknown; female with tergite VIII with emargination narrower, varying from moderately deep Ushape to minute triangular; female tergite X with apical projection distinctly longer than wide, disc distinctly raised at middle, top of raised area slightly depressed to flattened.
Distribution. Figure 21D. Known only from a small area in Fujian, China. Bionomics. Specimens have been collected in April-July at elevations ranging from 900-1100 m.
Comments. There have been concerns that this species was conspecific with B. taiwanensis due to the lack of a described male specimen and similarities in coloration (Smetana and Zheng 2000a). These species are both treated as valid herein based on clear differences in antennae and in the structure of female tergite X. This is presently the only described Oriental species with unknown male characters.

Loculus Group
The diverse members of the Loculus Group (Bolitogyrus feai, B. hainanensis, B. himalayicus, B. khasiensis, B. loculus, B. mulayitensis, B. nanus, B. pecki, B. smetanai, and B. solodovnikovi) all share a projected carina at the apex of the median lobe, which appears as a tooth in lateral view and a thickened lip in parameral view. Nearly all species of this group also have a medial group of peg setae that are distinctly larger than those of the lateral group. Basal teeth of the median lobe, when present, are always placed laterally. Cai et al., 2015 Fig. 16E-H, 22B (map) Bolitogyrus loculus Cai et al., 2015: 460. Type locality. Menglun Nature Reserve, Xishuangbanna, Yunnan, China.

Bolitogyrus loculus
Type material. The type series of this recently described, and well-illustrated species was not examined (Cai et al. 2015).
Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, forming broadly pale basal area composed entirely of yellow raised marking (similar to Fig. 6C); paramere strongly constricted apically (Fig. 16E); female tergite VIII with narrow emargination (Fig. 7A).
Distribution. Figure 22B. Known only from the type locality in southern Yunnan, China.
Bionomics. The type series was collected in February at elevations ranging from 560-860 m.
Comments. Bolitogyrus loculus is externally similar to B. flavus, especially to morphs of the latter with the minimum extent of pale coloration on the elytra (Fig. 6C). However, B. loculus can be recognized by the sparsely punctate sutural area of the elytra and the entirely darkened apex of the hind femur. Type material. The type series of this recently described, and well-illustrated species was not examined (Cai et al. 2015).

Bolitogyrus hainanensis
Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, not forming v-shape, medial and lateral markings of different sizes and never entirely fused (Fig. 5G); hind femur with dark marking on ventral portion only (as in Fig. 2C; antennomere 7 distinctly transverse (Fig. 6F).
Distribution. Figure 22B. This species may be endemic to Hainan island, China. Bionomics. Specimens have been collected in November and December at elevations ranging from 450-666 m.
Comments. Except for one, much larger, member of the Carnifex Group, B. hainanensis is presently the only species of Bolitogyrus on Hainan island, China. Bolitogyrus hainanensis is externally similar to B. vulneratus and B. pecki but differs by the bilobed paramere, presence of a medial group of peg setae and the recurved apex of the median lobe in lateral view. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, forming v-shape (Fig. 2E, 5H); epipleuron not entirely pale ( Coloration: head entirely dark; pronotum entirely reddish; scutellum reddish, at least at base, disc of elytra dark with yellow v-shaped, raised marking, base sometimes broadly reddish; epipleuron not entirely pale, with subapical darkened area; abdominal tergites III-V entirely reddish, VI varying from dark with reddish base to entirely reddish; antennomere 1 yellow with darkened apex, 2-5 light brownish-red with darkened apex, 6-10 dark brown, apical segment brownish to dark brown; palpi yellow-brown with apical segment slightly darker; legs yellow, midfemur with ventroapical darkened area, hind femur with apical area of femur darkened.
Pronotum slightly transverse to quadrate, about as wide as head, with sparse moderately impressed micropunctation on disc, becoming more distinct on anterior angles. Elytra distinctly transverse, suture distinctly shorter than pronotum at middle.
Abdomen with disc of tergites III-V distinctly, VI narrowly impunctate medially; sternites III-IV with basal line distinctly projected posteriad at middle.
Median lobe in lateral view with narrowed apical portion nearly straight, apex with tooth (Fig. 16J); median lobe in parameral view with expansion in apical two-thirds, with wide basal tooth set on ridge, apical portion evenly converging to acute apex (Fig.  16I); paramere slightly longer than median lobe, elongate spoon-shaped, apex broadly rounded (Fig. 16K); peg setae arranged in thin marginal group, with a fragment of a median group consisting of a few setae basad of marginal group (Fig. 16K); male sternite VIII with distinct but shallow emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct, deep emargination.
Female tergite VIII with median emargination moderately deep and varying from triangular to U-shaped; female tergite X elongate shield-shaped, with moderately projecting and rounded apex, disc distinctly raised, this area longitudinally impressed at middle.
Distribution. Figure 21A. Known only from the Bolaven Plateau in southern Laos. Bionomics. The type series was collected during May-June at 800-1200 m elevation. Specimens were collected using flight intercept traps and from tree fungi.
Etymology. This species is named in honor of Alexey Solodovnikov (ZMUC). His positive energy and endless support as a PhD supervisor and now, as close colleague and friend, continue to develop the next generation of systematists and push staphylinid research forward.
Comments. Bolitogyrus solodovnikovi is externally similar to allopatric B. feai and B. mulayitensis (both Myanmar) but can be distinguished by the epipleuron, which is only partly pale. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, forming v-shape (as in Fig. 2E); epipleuron entirely pale (as in Fig. 7C); antennomere 8-9 weakly transverse (Fig. 7E) Similar to B. solodovnikovi and differing only in the following: epipleuron entirely pale (Fig. 7C); pronotum with broad medial darkening; apical antennomere slightly paler (Fig. 7E); elytral suture relatively longer than pronotum at midline; pronotum slightly narrower than head; abdominal tergite VI entirely dark and punctate medially; antennomeres without distinctly darkened apices; median lobe in lateral view with apical portion more strongly narrowed to apex and slightly sinuate, not distinctly hooked, without basal teeth (Fig. 16M); median lobe in parameral view with shorter, acuminate apical portion (Fig. 16L); paramere about as long as median lobe, less elongate, peg setae arranged in shorter marginal group, median group composed of larger peg setae placed in a broader row basad of marginal group (Fig. 16O); male sternite VIII with shallower emargination. Female unknown.

Bolitogyrus feai
Distribution. Figure 21A. Known from the Karen Kills (Kayin State) in Myanmar. Bionomics. The holotype was collected in May at 900-1100 m.
Etymology. This species is named after Leonardo Fea , an Italian explorer and naturalist who collected a rich variety of Bolitogyrus specimens from Myanmar.
Comments. Bolitogyrus feai is most similar to B. mulayitensis from southern Myanmar but can be distinguished by the longer apical antennomeres and the presence of only traces of microsculpture on the frons.  Paratype (1 ♀,IRSNB): same data as holotype with AJB0000425. Diagnosis. This species may be recognized by the following: head entirely dark; pronotum widest in posterior third; elytra partly dark, discal markings of elytra extending onto epipleuron, forming v-shape (as Figs 2E, 7C); epipleuron entirely pale (Fig. 7C); antennomere 8-9 distinctly transverse (Fig. 7D) Similar to B. solodovnikovi and differing only in the following: pronotum with broad medial darkening; epipleuron entirely pale (Fig. 7C); abdominal tergites IV-V with medial darkening, VI entirely dark; apical antennomere distinctly paler than previous, yellow; head with distinct microsculpture on frons; pronotum distinctly (male) to slightly (female) more transverse; elytral suture relatively longer than pronotum at middle in female; abdominal tergite VI not distinctly impunctate at middle; median lobe in lateral view with apical portion triangular and ventral face slightly inflated, apex with minute tooth formed from median carina, basal teeth present and appearing removed from ventral face (Fig. 17B); median lobe in parameral view only weakly expanded at apical two-thirds, with apical portion shorter, with apex acute and rounded, basal teeth appearing at lateral margins (Fig. 17A); paramere far narrower, with long apical portion narrowed to apex, medial group of peg setae present and extended apicad to overlap with marginal group, medial setae distinctly larger than marginal setae (Fig. 17C); female tergite VIII with minute triangular emargination; female tergite X shield-shaped, with broadly rounded but projected apex, disc slightly raised and with slight longitudinal impression.

Bolitogyrus mulayitensis
Distribution. Figure 21A. Known only from Mt. Mulayit, in southern Myanmar. Bionomics. The type series was collected in March at a relatively high elevation (1800-1900 m).
Etymology. The species is named after Mulayit Taung, a mountain in southern Myanmar. The type series was collected near its summit.
Comments. Bolitogyrus mulayitensis is most similar to B. feai but can be distinguished by the distinctly transverse apical antennomeres and strong microsculpture on the frons. Diagnosis. This species can be recognized by the following combination of characters: orange frons contrasting with dark head (Fig. 2F); pronotal margin only weakly expanded, no more than three lateral puncture widths wide; apical antennomere not distinctly paler than previous segments (Fig. 2F) Coloration: head dark with orange frons; pronotum reddish orange with hourglass-shaped dark marking medially; elytral disc dark brown to dark brownish-red, with orange to yellow marking at middle and along suture, apical angles and humeri paler; scutellum dark; epipleuron pale along its length; abdominal tergites III-VI ranging from almost entirely dark, to reddish with central dark marking, VII entirely dark; antennomere 1 yellow, 2-5 reddish with dark apices, 6-10 dark brown, 11 vaguely paler; palpi yellowish; legs yellowish with small dark marking at ventral apex of femora.
Pronotum distinctly transverse, center of disc with very few micropunctures, about as wide as head. Elytra moderately transverse, suture shorter than pronotum at middle; elytral disc bearing a pair of small, raised, oval and light yellow markings near the center, and an additional, smaller pair laterad.
Abdomen with disc of tergites III-V distinctly, impunctate at middle. Median lobe in lateral view evenly narrowed to apex, ventral face flat, with minute pair of median teeth formed from median carina (Fig. 17E); median lobe in parameral view subparallel to rounded, acuminate apical portion, without subapical or basal teeth (Fig. 17D); paramere longer than median lobe, elongate spoon-shaped, peg setae in thin marginal group, basal-most setae removed from margin and disconnected from main group (Fig. 17F); male sternite VII with distinct, shallow emargination, and with triangular glabrous area medially; male sternite VIII with very slight emargination and elongate triangular, flattened and glabrous area medially; male sternite IX distinctly expanded at midlength, with distinct emargination.
Female unknown. Distribution. Figure 22B. Known from western Thailand and the Karen Hills of Myanmar.
Bionomics. Specimens were collected in March and May at both lowland and montane elevations (900-1100 m). It is unlikely that B. smetanai occurs over such a broad range of elevations and it is possibly that either Fea's material was mislabeled or the specimen from Thailand had washed down with heavy rain from a much higher point.
Etymology. This charming species is named in honor of Aleš Smetana (CNC), a close Canadian colleague and wealth of knowledge concerning the Staphylininae. His taxonomic contributions on the subfamily, including several on Bolitogyrus, form the modern treatments of the Nearctic and Oriental faunas.
Comments. Bolitogyrus smetanai is easily recognized by its small size, dark apical antennomeres and orange frons. Diagnosis. This species can be distinguished by the following character states: head entirely dark; elytral disc dark with pale markings extending halfway to epipleural margin (Fig. 5G); pronotal margin at its widest point no more than three lateral puncture widths wide but still distinctly expanded at hind angles; forebody less than four millimeters; apex of median lobe with single-toothed carina or 'lip' (Fig. 17J); paramere with dense apical cluster of peg setae (Fig. 17I).
Extremely similar to B. khasiensis and differing only in the following: medial and lateral elytral markings more broadly connected, pale area of epipleuron not restricted to humeral spot, pale in entire basal half; pronotum slightly more transverse; elytral suture relatively longer than pronotum at middle; forebody distinctly shorter and thinner; median lobe in parameral view with apex distinctly acuminate and acute, apical portion with single-toothed carina or 'lip' (Fig. 17J); paramere with peg setae closer to margins, removed from margins near base of rows, apex with dense field of peg setae (Fig. 17I). Female unknown.
Distribution. Figure 20C. Known from the Himalaya of West Bengal, India. Bionomics. The holotype was collected in October at 200 m and was sifted from leaves in a forest ravine (Smetana 1988).
Etymology. The species epithet refers to its distribution in the Himalayan mountains. Bolitogyrus himalayicus is the only described species known to occur in this region.
Comments. This is the species Smetana (1988)  Diagnosis. This species can be distinguished by the following character states: head entirely dark; elytral disc dark with pale markings extending halfway to epipleural margin (Fig. 5G); pronotal margin at its widest point no more than three lateral puncture widths wide but still distinctly expanded at hind angles; forebody less than four millimeters; apex of median lobe with double-toothed carina or 'lip' (Fig. 17L); paramere with only simple rows of peg setae and without dense field (Fig. 17K).
Extremely similar to B. khasiensis and differing only in the following: medial and lateral elytral markings more broadly connected, pale area of epipleuron not restricted to humeral spot, pale in up to entire basal half; pronotum slightly more transverse; elytral suture relatively longer than pronotum at middle; forebody distinctly shorter and thinner; median lobe in parameral view with apex distinctly acuminate and acute, apex with folded, double-tooted carina (Fig. 17L); paramere with sparse and simple rows of peg setae placed close to margin, removed from margin only at base of rows (Fig. 17K). Female unknown.
Distribution. Figure 20C. Known only from the Khasi Hills of Meghalaya. Bionomics. The holotype was collected in October at 1000 m. Etymology. The species epithet refers to the fact that this species is the smallest known in the Oriental fauna at 3.5 millimeters in forebody length.
Comments. Bolitogyrus nanus is extremely similar to allopatric B. himalayicus from West Bengal but is slightly smaller and the apex of the median lobe bears a doubletoothed carina and the paramere lacks the dense apical field of peg setae. Diagnosis. This species can be distinguished by the following character states: head entirely dark; elytral disc dark with pale markings extending halfway to epipleural margin (Fig. 5G), medial and lateral discal spots distinguishable and not forming distinct chevron or v-shaped marking or broad pale area; pronotal margin at its widest point no more than three lateral puncture widths wide but still distinctly expanded at hind angles; apex of hind femur with only vague dark marking on ventral margin; antennomere 7 distinctly transverse; paramere with distinct rows of peg setae (Fig. 17O).
Similar to B. khasiensis and differing only in the following: medial and lateral elytral markings much more broadly connected, pale area of epipleuron not restricted to humeral spot, pale in up to entire basal half; abdomen slightly paler, dark reddish brown toward the base; head and pronotum more transverse; elytral suture relatively longer than pronotum at middle; forebody distinctly broader, appearing more robust; median lobe with laterally placed basal teeth, in parameral view with apex bearing folded, single-tooted carina (Fig. 17M); median lobe in lateral view only simple apical tooth, with basal teeth appearing removed from lateral margin (Fig. 17N); paramere with slender apical portion, with sparse marginal and medial rows of peg setae, apex with dense field placed close to margin, apical setae extremely small, almost unobservable at lower magnifications (Fig. 17O). Female unknown.
Distribution. Figure 22B. Known only from northern Vietnam. Bionomics. The holotype was collected in May using an FIT in lowland forest (180 m).
Etymology. This species is named in honor of Stewart Peck (Carleton University, Ottawa, Canada), the collector of its holotype and many other rare taxa belonging to Staphylinini.
Comments. Bolitogyrus pecki is similar to the allopatric B. hainanensis from Hainan, China but can easily be distinguished by median lobe in lateral view, which is not recurved and the peg setae of the paramere, which are arranged in simple marginal and medial rows.

Undescribed species of the Loculus Group
A single female specimen from Kachin State, Myanmar (NHMW) was studied that is similar to B. smetanai but lacks an orange frons and likely represents an undescribed species.
Female tergite VIII with median emargination varying from small and triangular to moderately deep and elongate triangular; female tergite X elongate, with acute, acuminate apex; disc only weakly raised in apical half, not separated by ridges.

Bolitogyrus ornatipennis
Diagnosis. This species can be distinguished by the following character states: head entirely dark; elytral disc dark with pale markings not extending onto epipleuron (Fig. 5F); pronotal margin at its widest point no more than three lateral puncture Coloration: body dark; elytra reddish; abdominal tergite III mostly dark with lateroapical areas reddish, IV with middle dark and remaining area reddish, V entirely reddish, VI-VII dark with base and apex reddish, VIII dark; antennomere 1 yellow, II-V reddish, 6-10 dark brown, 11 pale yellow; palpi yellowish, apical segment darkened; legs yellowish, femora with dorsal surface darkened.
Head distinctly transverse; dorsal surface with moderately dense, clearly separated asetose punctures, frons with coarse depressions in addition to usual frontal impressions and with scattered punctures, frons bearing a pair of setose punctures between anterior frontal punctures. Antennomeres 7-10 transverse and asymmetrical.
Pronotum distinctly transverse, convex and with micropunctures scattered on disc, becoming rather dense on anterior angles. Elytra slightly transverse, slightly shorter than pronotum at middle, in addition to usual macrosetal rows on disc, scattered punctures bearing setae, nearly all punctures setose on epipleuron of elytron.
Abdomen with disc of tergites III-V distinctly impunctate; sternites III-IV with basal line distinctly projected posteriad at middle.
Median lobe in lateral view gradually narrowed apicad to level of single median, apical tooth formed from projection of apical carina, apex of median lobe slightly constricted apicad of tooth, median lobe with pair of basal teeth at about midlength (Fig. 18G); median lobe in parameral view elongate, asymmetrically sinuate in apical half (Fig. 18H); paramere slightly longer than median lobe, apical half leaf-shaped and slightly asymmetrical, peg setae arranged in thin marginal group and sparse medial group, marginal group broadens at apex into a pair of triangular shapes, median group consisting of a paired row extending basad of marginal group (Fig. 18I); male sternite VIII with shallow emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct emargination.
Female unknown. Distribution. Figure 20A. Known only from the type locality on Mt. Muria, Central Java.
Bionomics. The holotype was collected in February at 700-1000 m. Comments. Bolitogyrus doesburgi is the only Oriental species of the genus with an asymmetrical aedeagus. (Cameron, 1932  Diagnosis. Bolitogyrus signatus is easily recognized by the pronotum, which is widest at the anterior angles ( Fig. 2H-I). This species (especially the male) bears a remarkable resemblance to the Neotropical species of the genus.
Coloration: body dark; head, pronotum and abdomen entirely dark, elytra dark, each with yellow v-shaped marking; antennomere 1 yellow with darkened apex, 2-5 reddish-orange with darkened apices, 6-10 dark brown, 11 pale yellow; palpi yellowish with apical segment darkened; forecoxae yellow with basal fifth dark brown in both sexes, legs yellow, forefemur with dorsal surface dark brown, lateral face and dorsal surface of mid and hind tibia with subapical dark marking, tibia with lateral face darker.
Head strongly transverse, more so in male; dorsal surface including frons glossy with sparse, small and poorly impressed punctures; in male, lateral part of head beneath eye expanded ventrad. Antennomeres 8-10 distinctly transverse but not asymmetrical.
Pronotum transverse and widest at anterior angles, strikingly more strongly transverse in males than females, with lateral portions explanate in males, protuberance moderate (male) or distinct (female); medial part of disc almost entirely without micropunctures, anterior angles with many impressed micropunctures. Elytra slightly transverse, suture distinctly to slightly shorter than pronotum at middle, nearly all punctures of epipleuron setose.
Abdomen with disc of tergites III-VI distinctly impunctate. Median lobe in lateral view evenly converging to apex, ventral face nearly straight except for very apex flexed ventrad, without teeth (Fig. 18K); median lobe in parameral view slightly dilated to apical fourth, spoon-shaped with slightly acuminate apex (Fig. 18J); paramere distinctly longer than median lobe, dilated about midlength and weakly narrowed to elongate, parallel apical portion with truncate apex (Fig. 18L); paramere entire but with median suture to almost midlength, peg setae with thin marginal group, peg setae also scattered to each side of the midline (Fig. 18L); male sternite VIII with shallow but distinct emargination and triangular glabrous area medially; male sternite IX moderately expanded at midlength, with distinct emargination, partly fused to laterotergal sclerites at midlength.
Female with tergite VIII bearing large, circular emargination (Fig. 2I), tergite X shield-shaped with raised area elongate trapezoidal and without depression, apex truncate with acutely projected middle; gonocoxae with bases fused medially.
Distribution. Figure 20D. Likely endemic to Sri Lanka. Bionomics. Specimens were collected in September and December-January at 1160-1280 m. One specimen was collected by a malaise trap.
Comments. Bolitogyrus signatus is the only Oriental species of the genus to exhibit strong sexual dimorphism, as in some Neotropical species. The sclerites of the male and female genital segments are uniquely fused in this species.

Undescribed species near incertae sedis taxa
Two female specimens from Java are similar to B. doesburgi but may each represent a different species. One specimen was collected in lowland forest (locality illegible, 100 m, RMNH) and the other from the Pangalengan area of West Java (1200 m, BMNH).