taxonID	type	description	language	source
BD3D87DD6275DC4BAFD0FC0B9E25F896.taxon	type_taxon	TYPE SPECIES. — Hister ariasi Marseul, 1864, by monotypy.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD6275DC4BAFD0FC0B9E25F896.taxon	diagnosis	DIAGNOSIS. — Body oblong, moderately convex, with matte black integument. Dorsum combining coriaceous-reticulate ground sculpture and variable punctation (fine to coarse). Pronotum and elytra tightly articulated; ventral sclerites bearing deeply impressed, often crenate striae. Head: frontal stria complete (rarely medially interrupted); clypeus with widely crenate margins and straight apical edge; labrum finely punctate, anterolateral setal fringes dense; mandibles robust, inwardly curved, with straight subapical teeth and a setose prostheca; eyes large, convex, dorsolaterally bordered by erect setae. Pronotum moderately convex, reticulate-punctate, lateral stria deeply impressed, curved, weakly crenate; marginal stria complete laterally, broadly interrupted posteriorly. Elytra shiny, striae distinct: external subhumeral stria arcuate, internal reduced; striae 1 - 3 complete, 4 variable (shorter than 3), 5 apically restricted; sutural stria variably developed. Hindwing with unbranched costa, CuA and M veins basally divergent. Propygidium and pygidium with reticulate-punctate mix. Ventral sculpturing: prosternal lobe broadly rounded, sparsely punctate medially; mesoventrite finely sculptured, meso-metaventral sutural stria straight; metaventrite with diagnostic T-shaped suture, lateral striae extending toward metepisterna. Legs: protibia with 4 - 6 denticles and a robust spur; meso- and metatibiae with distally enlarged denticles; mesofemur bearing dual longitudinal setal rows. Tergite X from irregular to with microscopic dentition. Aedeagus slender, parameres apically expanded; spiculum gastrale variable (Y-shaped to slingshot).	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD6275DC45AFAEF8CF9E42FBF7.taxon	description	(Figs 1 - 3; 10)	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD6275DC45AFAEF8CF9E42FBF7.taxon	materials_examined	TYPE LOCALITY. — China, Shanghai. TYPE MATERIAL. — Syntype. China • Shanghai; MNHN-EC-EC 60885 (examined by Prof. Masahiro O’Hara). MATERIAL EXAMINED. — India. Punjab • 15 ♂, 3 ♀; Amritsar; 31 ° 36 ’ 2.05 ” N, 74 ° 52 ’ 31.70 ” E; 8. IV. 2022; J. Kumar col.; JASENT 2022001 - 015, JASENT 2022016 – 018; PUZEC • 5 ♂; Nawanshahr; 31 ° 6 ’ 39.24 ” N, 76 ° 9 ’ 36.42 ” E; 20. VI. 2023; J. Kumar col.; JASENT 2023001 - 005; PUZEC • 2 ♂, 20 ♀; Mullanpur Garibdas; 30 ° 79 ’ 42.247 ” N, 76 ° 74 ’ 90.211 ” E; 11. III. 2023; J. Kumar col.; JASENT 2023006 - 007; JASENT 2023008 - 027; PUZEC.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD6275DC45AFAEF8CF9E42FBF7.taxon	distribution	DISTRIBUTION. — India, Kuril Isls., Japan, Siberia, Far East Russia, Sakhalin, Korean Peninsula, Jeju Is., China, Taiwan, Philippines (Ôhara 1992; Mazur 2011).	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD6275DC45AFAEF8CF9E42FBF7.taxon	diagnosis	DIAGNOSIS. — The labrum bears fine, dense anterolateral setal fringes. Mandibles are robust, inwardly curved, and terminate in a blunt apical tip; their surface is finely punctate, overlain by an alutaceous-reticulate ground sculpture that coarsens laterally. A straight subapical tooth lies anterior to a dense cluster of large, golden prosthecal setae. The protibia bears 3 - 6 denticles, while mesotibiae and metatibiae exhibit dual rows of denticles differing in size. Male genitalia (Fig. 4 D, E): The aedeagus (tegmen) is slender, laterally sclerotized, with inwardly curved median parameres and bulbous apical parameres. The basal piece forms a sclerotized ring encircling the posterior margin, connecting to the parameral basal margins. The tergite X displays denticulate lateral edges, with remaining areas brownish and heavily sclerotized.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD6275DC45AFAEF8CF9E42FBF7.taxon	description	REDESCRIPTION Body (Fig. 1 A-E) Oblong, moderately convex; matte black with faint metallic luster; surface uniformly clothed in coriaceous-reticulate microsculpture. Prothoracic setae golden, short, recumbent; elytra dark, shiny. Measurements provided in Table 1. Head (Figs 1 A, C, E; 2 A) Surface covered with minute punctures (Fig. 2 A). Frontal stria complete, anterior contour rounded to straight, margins crenate, narrowly interrupted at midpoint in some specimens; frontal disc glossy, microsculpture coriaceous-reticulate (Figs 1 A, C, E; 2 A). Clypeus laterally expanded, margins broadly crenate; apex straight. Labrum finely punctate, anterolateral margins bearing dense fringes. Mandibles robust, inwardly curved, apically blunt; lateral surface coarsely punctate, prostheca depressed anterior to subapical tooth; prosthecal setae dense, elongate. Eyes large, convex, dorsolateral margin with row of erect setae (Fig. 1 E). Postoccipital suture encircled by dense cluster of short setae (Figs 1 B; 2 A). Pronotum (Figs 1 A, C-E; 2 B, D) Pronotal disc clothed with reticulate ground sculpture intermixed with microscopic punctures (Figs 1 A; 2 B). Lateral portions bearing dense mixture of microscopic and larger punctures, extending narrowly toward anterior angles (Figs 1 C; 2 D); punctation denser anteriorly and posteriorly, sparser medially. Antescutellar region with short longitudinal punctures (Fig. 1 A); marginal punctures sparse anteriorly, denser approaching pronotal lateral stria (Figs 1 A; 2 D). Marginal pronotal stria complete laterally, broadly interrupted behind head (Fig. 1 C). Lateral pronotal stria deeply impressed, arcuate, weakly crenulate (Fig. 1 A, C-E). Elytra (Figs 1 A; 2 C) Surface dark, shiny, densely punctate; marginal stria complete, finely crenulate (Figs 1 A; 2 C). Epipleural fossette with large, deep punctures forming longitudinal groove along lateral margin; epipleural stria marginal along apical half (Fig. 1 C). External subhumeral stria arcuate; internal subhumeral stria reduced, obsolete. Dorsal striae 1 - 3 complete, finely impressed, none contacting basal margin (Figs 1 A; 2 C); interstitial punctures minute, aligned to contact anterior margins. Fourth stria variable in length, consistently shorter than third; striae 1 - 4 weakly arcuate laterally (Fig. 1 A). Fifth stria abbreviated, confined to apical fourth, rarely extending beyond midlength. Sutural stria incomplete, extending from base to apical third. Striae margins externally crenulate throughout. Hind Wings C unbranched, extending to anterior wing margin; Sc unbranched, originating from first axillary sclerite; A connecting third axillary sclerite; shorter branch terminating medially before wing center; PCu contacting posterior wing margin, not extending to wing base; Cu and M diverging basally; Cu curving anterad toward anal vein; M extending posteriad toward Sc, connecting median plate (Fig. 5). Propygidium and Pygidium (Fig. 1 F) Propygidium with reticulate ground sculpture intermixed with coarse, shallow, rounded punctures, diminishing in size posteriorly; pygidium clothed with punctures transitioning finer as density increases. Both regions bearing combined fine and coarse punctation. Prosternum (Figs 1 B; 2 H) Prosternal lobe apex rounded; disc sparsely punctate at center, punctures coarser laterally. Marginal stria crenulate, fading medially, connecting to lateral margins of lobe, occasionally encircling apex entirely. Parallel crenulate striae originating near basal margin, extending to posterior half. Prosternal keel broad; lateral stria nearly contacting prosternal suture. Mesoventrite (Figs 1 B; 2 I, K) Discal marginal stria crenulate, sinuate, bluntly angulate medially, shortened anteriorly, not attaining lateral metaventral suture. Disc with microscopic reticulate microsculpture. Meso-metaventral sutural stria straight, shortened anteriorly, failing to meet discal marginal stria but both intersecting post-mesocoxal stria. Metaventrite (Figs 1 B; 2 I, K) Lateral disc with coarse punctures and sparse setae. Lateral metaventral stria crenulate, irregular, uniting anteriorly with meso-metaventral sutural stria, extending posteriorly to intersect metepisternal stria. Longitudinal metaventral suture forming T-shaped junction with meso-metaventral sutural stria (Figs 1 B; 2 I). Anepisternum (Fig. 2 K) Surface bearing light brown setae and coarse punctures. Abdomen (Fig. 2 I, J, M) First abdominal ventrite trapezoidal (Fig. 2 J); disc clothed with intermixed small and large punctures, occasionally arranged in striae-like rows anteriorly. Lateral stria of ventrite 1 deeply impressed, crenulate. Intercoxal disc bearing anterior row of coarse punctures, with sparse punctures extending toward longitudinal metaventral suture (Fig. 2 I). Apparent abdominal ventrites 1 - 5, progressively narrower posteriorly (Fig. 2 J, M). Legs Protibia (Figs 2 E, N; 3 A). Densely punctate, dark brown; dorsal margin with 4 - 6 denticles (Fig. 2 E), surface reticulate, setae occasionally reduced. Protibial spur prominent at anterior angle (Fig. 3 A); tibial groove margin bearing row of setae, sometimes reduced. Outer margin with row of robust setae near first denticle (Fig. 2 E). Protarsus length c. 0.2 mm, base slender, glabrous. Claw ultimate segment cylindrical, length c. 0.3 mm. Anterior protibial stria flanked by 4 - 6 - minute denticles (Fig. 2 N); ventral strial region occasionally with diminished denticles or glabrous patches. Posterior protibial spur and ventral first denticle bearing 4 diminutive denticles (Fig. 2 N); inner setal row present basad of stria. Profemur (Fig. 3 A). Coriaceous-reticulate microsculpture, punctate, subrectangular; dorsal setae arranged in scalene triangle; ventral surface with longitudinal groove, reticulate microsculpture basad. Distal end weakly swollen, stria originating dorsally, not attaining tibial base. Dorsal cluster of bristle-like setae near tibial articulation. Mesotibia (Figs 2 F; 3 D). Dark brown; dorsal margin with two denticulate rows, denticle size increasing apicad. Outer surface with three setal rows (Fig. 2 F): inner row ventrally positioned, irregularly spaced; outer row sclerotized, adjacent to dorsal denticles; middle row extending near mesotibial spur. Four apical spurs; tarsomere 1 with two pairs of spines, remaining tarsomeres each with single pair. Mesofemur (Fig. 3 C). Dark brown; posterior surface with dual setal rows; ventral setae restricted to basal half; dorsal setae sparsely distributed. Anterior surface punctate, glabrous. Metatibia (Fig. 2 F). Similar to mesotibia but elongate; dorsal denticles and setal rows proportionally extended. Male genitalia Tergite VIII (Fig. 4 A). Posterior margin medially arcuate, semicircular; anterior margin with deep, angulate median emargination. Sternum VIII (Fig. 4 A). Broadly ovate (1: 1.2 L / W), glossy, glabrous. Margins ornamented by sclerotized, amber-tinted patches; anterior convex, sparsely setose; posterior emarginate with symmetrical, rounded lobes. Translucent golden-amber center grading to smoky margins; paired anterolateral fuscous blotches. Spiculum gastral (Fig. 4 C). More slingshot shape; bifurcate, moderately sclerotized; stem broad, slightly flattened, dividing into two slender, symmetrically divergent arms forming open V-angle; arms narrowing to rounded apices, inner margins smooth. Tergite IX (Fig. 4 B). Bilobed, broadly ovate; lobes symmetrical, weakly convex, apically tapered. Medial margin shallowly emarginate, forming narrow midline gap. Sclerotisation moderate to heavy, pigmentation grading from pale amber basally to golden-brown distally. Surface finely granulate, densely punctate medially and sublaterally; punctures small, shallow, uniform, interspersed with circular sclerites. Margins smooth, arcuate laterally and posteriorly; anterior margin broadly rounded, anterolateral angles weakly elevated. Tergite X. Elongate, narrowly lobed; lobes spatulate to sub rectangular, apically tapered. Sclerotisation heavy, posterior margins amber; surface sparsely punctate laterally and apically, medially glabrous. Apical margins rounded to subacute, occasionally minutely emarginate; apex and lateral margins bearing sparse, sclerotized patches. Moderately membranous, margins finely denticulate. Aedeagus (Fig. 4 D). Slender, elongate (c. 5.6 × longer than wide); lateral margins smooth, sclerotized, tapering apically. Basal piece forming complete sclerotized ring, posterior margin continuous with parameral bases; short, robust, suboval, heavily pigmented. Tegmen elongate, tubular, moderately sclerotized; surface smooth, glabrous. Median lobe strongly sclerotized, sculptured with complex armature, visible through tegmen as darker internal shaft, gradually tapering posteriorly. Parameres distinctly separated, apically lobate, bulbously expanded (c. 0.72 × wider than median region); bilobed, symmetrical, lightly sclerotized; apices rounded, glabrous.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD627BDC41AFD2FB2D9FF3F872.taxon	description	(Figs 6 - 10)	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD627BDC41AFD2FB2D9FF3F872.taxon	materials_examined	TYPE LOCALITY. — India: Dehradun, United Provinces. TYPE MATERIAL. — Presumed holotype. India • ♂; labelled, Dehradun, United Provinces, India; under bark of spruce; Mr. E. P. Stebbing; NHMUK, formal designation lacking and type status unconfirmed. MATERIAL EXAMINED. — India. Punjab • 4 ♂; Amritsar, 31 ° 36 ’ 2.05 ” N, 74 ° 52 ’ 31.70 ” E; 8. IV. 2022; vouchers JAS. ASKENT 2022001 - 004; J. Kumar col.; PUZEC • 1 ♀; same data as preceding males; voucher JAS. ASKENT 2022005; J. Kumar col.; PUZEC.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD627BDC41AFD2FB2D9FF3F872.taxon	distribution	DISTRIBUTION. — India: Dehradun (Mazur 2011).	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD627BDC41AFD2FB2D9FF3F872.taxon	diagnosis	DIAGNOSIS. — Five elytral dorsal striae visible, the striae 1 - 4 fully formed, fifth stria short, second and fourth striae not connected to the base. Protibial outer margin slightly curved and having three denticles. Spiculum gastrale smaller and Y-shaped Tergite X shallowly emarginate, margin angulate and irregular apical margin.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD627BDC41AFD2FB2D9FF3F872.taxon	description	REDESCRIPTION Head (Fig. 7 A). Surface irregularly punctate; cranial stria complete, supraorbital stria arcuate, frontal stria nearly straight, positioned slightly ventral to clypeus. Eyes convex dorsally, bordered posteriorly by cluster of light brown setae. Antennal scape punctate, distally bearing cluster of pale brown setae near pedicel; pedicel laterally concave on one margin, convex on opposite margin; flagellum sparsely setose throughout. Labrum transverse (width: length c. 3: 1), finely punctate, anterolateral margins densely fringed. Mandibles robust, inwardly curved, apically blunt; lateral surface coarsely punctate, broader basally; ventral surface with straight subapical tooth; prostheca depressed proximally, prosthecal setae dense, golden; mandibular surface entirely punctate-reticulate. Pronotum (Figs 6 A; 7 B) Anterior margin concave, posterior margin straight (anterior margin length c. 0.5 × posterior margin); disc convex, microsculpture reticulate, interspersed with minute punctures. Lateral disc densely punctate anterolaterally and posterolaterally; marginal stria complete laterally, broadly interrupted behind head. Lateral stria prominent, not attaining posterior pronotal margin. Antescutellar region nearly smooth, bearing single longitudinal puncture. Elytra (Figs 6 A; 7 C) Width c. 1.4 × length; surface clothed in microscopic punctures and reticulate ground sculpture. Epipleural marginal stria moderately impressed along median third. Elytral striae strongly carinate throughout. Inner subhumeral stria abbreviated; oblique humeral stria connecting to first dorsal stria. Dorsal striae 1 - 3 complete, weakly arcuate laterally, reaching basal margin. Fifth stria variable in length, sutural stria carinate, abbreviated, extending slightly beyond midlength. Hind wing venation (Fig. 9) C unbranched, attaining anterior wing margin; first axillary sclerite bearing anterodistal projection at wing base. Sc unbranched, originating from first axillary sclerite. M and Cu connected to median plate. PCu arising near A, not attaining wing plate; anal vein bearing short lateral branch basally. Anal lobe bilobed; third axillary sclerite anatomically linked to anal vein. Propygidium and Pygidium Propygidium with reticulate ground sculpture intermixed with coarse, rounded, shallow punctures, diminishing in size posteriorly; pygidium clothed with serial punctures. Prosternum (Figs 6 B; 7 H) Prosternal lobe anterior margin rounded, punctate; medio-apical marginal stria deeply impressed, crenate, ascending medio-apically. Basolateral margin with abbreviated striae, two oblique punctures intersecting basolateral stria medially. Interpunctural spaces finely punctate; prosternal process sparsely punctate. Presternal suture deeply incised. Prosternal keel lateral stria nearly straight, crenulate-punctate; keel surface finely punctate, base subglobose. Mesoventrite (Figs 6 B; 7 I) Discal marginal stria carinate, interrupted behind prosternal keel base, forming deep crescentic impression; disc sparsely punctate. Meso-metaventral sutural stria nearly linear, weakly crenulate. Metaventrite (Figs 6 B; 7 I) Lateral stria deeply impressed, carinate, extending obliquely posteriorly, converging posteriorly with recurrent stria. Post-mesocoxal stria deeply impressed, strongly arcuate along mesocoxal posterior margin. Metepimeron with coarse, rounded punctures. Longitudinal metaventral suture weakly impressed, anteriorly forming T-shaped junction with meso-metaventral suture; posteriorly, two fine sutures angling obliquely from suture base toward recurrent stria. Intercoxal disc with punctures denser near lateral stria, sparser medially. Metepisternum Surface bearing coarse punctures and sparse setae; metepisternal stria anteriorly uniting with oblique stria, extending laterally to mesocoxal margin, joining anepisternum. Abdomen (Figs 6 B; 7 J) Ventrite I. Trapezoidal; lateral stria deeply impressed, crenulate; intercoxal disc with reticulate ground sculpture overlain by sparse microscopic punctures. Legs Protibia (Fig. 7 E). Dark brown, surface punctate-reticulate; denticles variably present, ventromedial miniature denticles often reduced or absent. Outer setal row extending from base to basal denticle, curving irregularly beyond posterior denticle; protibial stria faintly visible. Basal margin with inner row of light brown setae, small setal tuft near tibial spur; mid-row punctures glabrous; posterior surface punctate, microsculpture coriaceous. Protarsus. Length c. 0.2 mm; slender, glabrous; tarsomeres 1 - 4 each with single apical spine; tarsomere 5 with paired apical spines. Profemur. Subrectangular; surface coriaceous, punctate; anterodorsal half with setae arranged in scalene triangular cluster; posterior half bearing longitudinal groove-like impressions; distal end with reticulate microsculpture; dorsal setae in single row; anterior edge with sparse, rounded punctures bearing hollow setal bases, not attaining tibial articulation. Mesotibia. Dark brown; dorsal margin with two denticulate rows, increasing in density toward tibial spur; posterior surface with three setal rows: inner row densely clustered ventrally (adjacent to spur), median and outer rows sparser. Mesofemur. Posterior inner margin with dense setal row, terminating before tibial base; anterior surface punctate, glabrous. Mesotarsus. Tarsomeres 1 - 4 each with single apical spine (contrasting protarsus). Metatibia. Structurally similar to mesotibia but proportionally elongate; dentition and setal patterns consistent, adjusted for length. Male genitalia Tergite VIII (Fig. 8 A). Subrectangular, broader than long, transversely oriented, with flat dorsum and straight to weakly convex lateral margins. Anterior margin straight to faintly convex, unmodified, uniformly sclerotized. Lateral margins smooth, tapering posteriad to angular posterolateral corners. Posterior margin bisinuate: lateral concavities flanking paired, sharp posterolateral projections; medial emargination broad, U-shaped (c. 120 °), base smooth. Surface entirely glabrous, polished, lacking sculpturing; texture matte to faintly lustrous. Sclerotisation moderate to heavy, uniform; pigmentation homogeneous pale brown-amber. Sternum VIII (Fi g. 8 A). Body semicircular to subpentagonal, marginally and dorsally ornamented with sclerotized amber-tinted patches; transverse (slightly wider than long), widest at anterior third. Anterior margin strongly arched, dome-like, with sparse marginal setae; posterior margin deeply V-emarginate, forming parallel, elongate lobes. Cuticle polished, glabrous; sclerotisation gradient dense (anterior) to translucent (posterior). Ground color amber, darkest marginally, with anteromedial subtriangular fuscous spot. Sparse, outward-projecting setae on anterior / lateral margins. Tergite IX (Fig. 8 C). Paired, robust, elongate-oval sclerites occupying lateral thirds of dorsum; anteroposteriorly convex, margins smooth, tapering posteriorly to blunt apices. Medial edges separated by narrow, translucent intersegmental membrane, contrasting dense amber sclerotisation of sclerites with paler midline. Surface glabrous, polished, regular. Posterior margin weakly truncate, medially emarginate, forming a shallow notch framing the anterior edge of tergite X; edge smooth. Coloration medium to dark amber, darkest along anterolateral margins, fading to translucent golden-yellow medially; anteromedial triangular fuscous spot near midline. Latero-apical processes arising dorsolaterally from anteroposterior midpoint of tergite IX: slender, arcuate, strongly sclerotized, reddish-brown; broad base integrated seamlessly with tergite, tapering to acute, outwardly curved apex; surface polished. Tergite X (Fig. 8 C). Narrow, weakly sclerotized, hyaline; posterior margin shallowly emarginate, margin angulate, pointed, irregular; contour smoothly rounded; anterior margin bordered by tergite nine, tapering slightly ventrally; cuticle finely micro-reticulate. Coloration uniform translucent pale amber, grading to slightly darker ochre at anterior edge where overlapping tergite IX; internal musculature or membranous structures faintly visible. Aedeagus (Fig. 8 B). Elongate (5.6 × longer than wide); phallobase (basal piece) short (c. 1 / 7 total length); parameres fused apically, forming broadly oval apex; median lobe elongate, encircled strongly sclerotized armature; tapering gradually to narrowly rounded terminus. Spiculum gastrale (Fig. 8 D). Y-shaped; moderately to heavily sclerotized; basal shaft robust, cylindrical, dorsoventrally compressed (flattened laterally); uniform width before tapering toward bifurcation; diverging into two symmetrically arcuate rami forming open V-angle; ramus margins smooth, glabrous, unornamented; inner margins concave, outer margins convex (balanced arcuate profile); apices narrowly rounded; sclerotisa - tion uniform (amber-light brown), marginally darker basally.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
BD3D87DD627EDC5FAC92F9CD9F5FF872.taxon	description	PRINCIPAL COMPONENT ANALYSIS (FIGS 11; 12; TABLES 2 - 5) Morphometric variation between Merohister jekeli and M. asoka was assessed using Principal Component Analysis (PCA) (Table 4) on 14 continuous traits measured across 26 adult specimens (Table 3). The first principal component (PC 1) explained 73.08 % of total variance and was character - ized by uniformly positive loadings across all traits (range: 0.167 - 0.298), indicating a dominant size axis. Traits with the highest contributions to PC 1 included pronotal length (PL, 0.298), pronotal posterior length (PPL, 0.298), pronotal width (ProW, 0.297), and elytral length (EL, 0.288), collectively reflecting overall body robustness. The second component (PC 2), accounting for 7.95 % of variance, revealed a shape-based contrast between cephalic and appendicular dimensions. Head width (HW) exhibited the strongest positive loading (0.557), while total length (MTTL) loaded negatively (- 0.488), indicating that PC 2 separates individuals with broader heads and shorter metatarsi from those with narrower heads and elongated hind appendages. This axis effectively distinguished M. asoka, which clustered toward high PC 2 values, from M. jekeli, which occupied lower PC 2 space. PC 3 (5.73 % variance) further resolved appendicular variation, MSTL showing a strong negative loading (- 0.663) and MTTL a positive loading (0.519). These patterns highlight differential scaling of mesotibia and metatibia segments, reinforcing interspecific separation. A PC 1 – PC 2 biplot revealed minimal overlap between species, with M. asoka occupying a distinct morphospace defined by larger body size and broader cephalic proportions. Based on PCA loadings and species-level separation, five traits – HW, MTTL, MSTL, ProW, and PL – were identified as the most reliable traits for distinguishing M. jekeli and M. asoka, and were subsequently used to construct morphometric diagnostic ratios. CANONICAL DISCRIMINANT ANALYSIS (FIGS 13 - 15) Canonical Discriminant Analysis (CDA) (Table 5) revealed a robust separation between M. jekeli and M. asoka, with a single discriminant axis (F 1) accounting for 100 % of the intergroup variability. The model yielded a canonical correlation of 0.978 and an eigenvalue of 21.837, indicating strong discriminatory power. Multivariate tests including Wilks’ Lambda (λ = 0.044, F (14 11) = 17.158, p <0.0001), Pillai’s Trace, Hotelling-Lawley Trace, and Roy’s Greatest Root all confirmed significant differences in mean vectors between species. Box’s M test rejected the assumption of equal covariance matrices (p <0.0001), validating the use of CDA over LDA. Classification accuracy was perfect, with 100 % of specimens correctly assigned to their respective species. The ROC curve yielded an AUC of 1.0, confirming complete separation in canonical space (Fig. 15). Group centroids on F 1 were − 10.529 for M. asoka and + 1.914 for M. jekeli, with no overlap in discriminant scores (Fig. 13). Among the 14 morphometric characters analyzed, ProW emerged as the most influential variable (standardized coefficient = + 4.192, p = 0.038), followed by APW (+ 2.869, p = 0.014), EL (+ 0.434, p = 0.031), and MTTL (+ 0.550, p = 0.066) (Fig. 14). Although some characters such as PTL and PyL were not individually significant, their high canonical loadings suggest multivariate relevance due to covariance structure. These traits collectively define a diagnostic morphometric profile distinguishing the two taxa.	en	Kumar, Jasvinder, Ôhara, Masahiro, Wats, Meenu, Jaiswara, Ranjana (2026): An integrative approach in taxonomic revision of the genus Merohister Reitter, 1909 (Coleoptera, Histeridae) from India, with redescriptions of M. jekeli (Marseul, 1857) and M. asoka (Lewis, 1910). Zoosystema 48 (11): 305-322, DOI: 10.5252/zoosystema2026v48a11
