Xenorthrius Gorham, 1892

Gerstmeier, Roland & Eberle, Jonas, 2010, Revision of the Indo-Australian checkered beetle genus Xenorthrius Gorham, 1892 (Coleoptera: Cleridae, Clerinae) 2584, Zootaxa 2584 (1), pp. 1-121 : 7-11

publication ID	https://doi.org/ 10.11646/zootaxa.2584.1.1
persistent identifier	https://treatment.plazi.org/id/03F45644-013D-FFDE-6FD3-F8D9DACBB4DE
treatment provided by	Felipe
scientific name	Xenorthrius Gorham, 1892
status

Treatment

Type species: Xenorthrius mouhoti Gorham, 1892 Gorham 1892: 733, 1893: 575 ; Schenkling 1903a: 46–47. Head: Punctation setiferous, interstices among punctures shiny; labrum bilobed, anterior margin densely vested with short setae, remainder laterally vested with longer setae; anterior part of clypeus semi-transparent, smooth, anterior margin of posterior part of clypeus mostly concave, posterior margin mostly convex; distal part of clypeus trapezoidal, proximal part usually darker than anterior part; terminal maxillary palpomeres digitiform, darker than other segments; terminal labial palpomeres securiform ( Fig. 1 View FIGURE 1 ); mandibles laterally vested with long setae; eyes coarsely facetted, protruding laterally, margined, emarginate at antennal insertion, with sparse pubescence between ommatidia; interocular space larger than one eye width (as viewed from above); genae behind the eyes with distinct wrinkles; gula smooth, gular process interspecifically varying in width ( Fig. 2 View FIGURE 2 ); antennae with 11 antennomeres, filiform ( Fig. 3A and C View FIGURE 3 ), length interspecifically variable ( Fig. 3 View FIGURE 3 ) and sometimes sexually dimorphic (longer in males), scape bent, flattened towards the eyes, A1 longer than A2, A2 shorter than A3, terminal three antennomeres forming a club ( Fig. 3C View FIGURE 3 ), A11 elongate in X. stefanieae and X. berndi ( Fig. 3D View FIGURE 3 ), antennomeres vested with short setae, club tomented yellowish to white.

Thorax: Punctation setiferous, interstices among punctures shiny; pronotum longer than wide ( Fig. 4A View FIGURE 4 ) or subquadrate ( Fig. 4B View FIGURE 4 ), sides slightly to distinctly convex between anterior and posterior transverse depressions ( Fig. 4C View FIGURE 4 ); each side of pronotum with a dorsolateral fovea; subapical transverse depression slightly impressed; prebasal transverse depression distinct; punctation mostly coarser on pronotum proper; pronotal arch broadest centrally; collar broadened laterally; prosternum smooth, sometimes with microsculpture, not pilose except for a line of setae at the anterior margin, pro-intercoxal process narrow, often dilated distally ( Fig. 1 View FIGURE 1 ); procoxal cavities wide open behind; mesosternum coarsely punctured to wrinkled, anterior mesosternal process distinct, narrow, with a subtriangular sulcus in the middle, intercoxal mesosternal process projecting ventrally; ventral part of mesepisternum smooth (except X. cruralis and X. tuberculicollis ) with isolated, often large punctation, dorsal part coarsely punctured; punctation of metasternum fine, discriminal line smooth; metendosternite ( Fig. 5) not significantly varying, furcal arms broad, apically dilated, laminae well developed.

Elytra: Elytral base without abrupt margin, lateral margins subparallel, elytra broadest behind middle, apices rounded (most species), strongly dehiscent ( X. prolongatus and X. furcalis )( Fig. 6B View FIGURE 6 ), or dentate ( X. truncatus and X. scordalus )( Fig. 6A View FIGURE 6 ); setae arising from between striae and among punctation, punctation asetiferous, often more distinct in basal half and in darker areas, in most species punctation in basal half of elytra rasp-like (meaning the interstices among punctation bulging over the punctures, see Fig. 7 View FIGURE 7 ), punctation often obsolete in the middle of elytron near suture; subcutaneous structures of elytra mostly visible through lighter areas (this often makes punctures appear larger than their actual size); elytral punctation arranged into ten striae, in some species additional punctures are present between the striae, one species with more or less irregular punctation ( X. temeris ), in most of the species the interstices in the apical half of elytra are carinated; hindwing ( Fig. 8 View FIGURE 8 ) with wedge cell open, anal anterior 1+2 very small or absent, margin of radial cell strongly sclerotized, the highest interspecific variability occurs in anterior cubital veins and posterior medial veins 3 and 4 where some proportions slightly differ, in some specimens cubitus anterior 1 is very short or even obsolete.

Legs: Mostly relatively short, metatibiae often slightly bent; tarsal pulvillar formula 4-4-4, tarsal pulvilli bilobed, basal pulvillus often obscure, particularly that of the metatarsus; tibial spur formula 1-2-2; tibiae with or without longitudinal carinae; claws with pronounced basal denticle ( Fig. 9); trochanter densely vested with short setae, femora and tibiae vested with short decumbent setae and longer erect setae dorsally, tarsal setae short.

Abdomen: Six visible abdominal sternites, apical margin of male ventrite 6 more or less distinctly emarginate, female ventrite 6 without emargination; abdominal metaintercoxal process narrow; vestiture yellowish, ventrites vested with fine setae, surface with microsculpture and fine punctation, apical margin of ventrites 1 to 4 broadly pale margined, pale margin smooth; male reproductive organs with tegmen mostly elongate, cross-section subrectangular, lateral sclerotization weak; ventral sclerotization with two branches in a V-shape; spiculae of spicular fork dilated apically.