Trachys scapulis Peng, 2021

Trachys scapulis Peng , new species

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( Figs. 19–21 View Figs )

Type Specimen. Holotype ( BPCQ), female, labeled: “Wutaishan, altitude 400 m, 32°10′N 110.73′E, Fangxian , Hubei, China, 29-VII-2019, Leg. Z-L. Peng et Y-Q. Cai ”.

Description. Habitus ( Fig. 19 View Figs ): Length 3.8 mm, width 1.9 mm, surface uniformly golden brown, underside brown with slightly bronze reflections; a long and robust, ovate species. Head: Widely excavated between eye; vertex transversely convex, uniformly covered with distinct scale-like or ocellate sculpture, irregularly clothed with brown-yellow pubescence mixed with sparse, pale pubescence, frons depressed along midline with a longitudinal groove, covered with dense, recumbent, pale pubescence; eyes reniform; antennal sockets situated just above lower margins of eyes, wide and deep; clypeus golden bronze, metallic and shiny; anterior margin arcuately and deeply emarginate; clypeal suture arcuate; lateral sides narrowed at midlength; antennae long, reaching past anterior margin of pronotum when laid alongside; antennal scape moniliform, 1.21 times as long as wide; pedicel shorter than scape, subcylindrical, 1.52 times as long as wide; antennomeres 3 – 6 cylindrical, much shorter than antennal scape and pedicel and slightly shorter than remaining apical ones, 1.52 times as long as wide; antennomeres 7 – 11 serrate. Pronotum: About 2.8 times as wide as long, widest at base, basal margin 1.92 times as wide as anterior margin in dorsal view, nearly as wide as elytra at base but much narrower than at elytral humeri; lateral margins very sharply tapering from base to acute anterior angles; anterior margin biarcuate with weakly produced median lobe; basal margin trisinuate, median lobe rather angulately produced posteriorly and rather acuminate apically; disc more or less convex but slightly depressed along basal margin, surface uniformly covered with scale-like or ocellate sculpture, densely and nearly uniformly clothed with brown-yellow pubescence mixed with sparse, white pubescence, slightly glabrous centrally. Scutellar shield: Very small but clearly visible, triangular, smooth. Elytra: 1.37 times as long as wide, about 4.2 times as long as pronotum, widest at and very strongly projecting at humeri; lateral margins slightly diverging from base to humeri, deeply emarginate from humeri to midlength, then arcuately converging to apices; apices jointly arcuate without distinct apical and lateral denticles; elytral surface convex; humerus strongly expanded as a bump each side; basal depressions rather wide; entire surface nearly evenly covered with brown-yellow pubescence except for markings of white pubescence consisting of three spots on basal half and two transverse zigzag bands on apical half. Lateral view ( Fig. 20 View Figs ): Thickest point lying at basal third of elytra; maximal thickness greatly exceeding length of pronotum plus head; curvature with angle of 115° between pronotal margin and subhumeral lobe; basal part of elytral margin obliquely straight with obtuse angle above metaventrite, humeral carina indistinct, with only an arcuate convex trace. Underside ( Fig. 21 View Figs ): Irregularly covered with short white pubescence, denser near sides; prosternal process about 1.7 times as long as wide, widest at apical angles; apical angles weakly acute, lateral margins narrowed at middle; apical margin arcuate; surface sparsely punctate with sparse pubescence; anterior part of prosternum transverse, narrow, anterior margin broadly emarginate, posterior margin transversely arcuate on each side, lateral margins slightly oblique; hypomeron with a subovate depressed marking near inner side, outside quite smooth, depressed marking covered with dense micro-wrinkles; metaventrite with sparse ocellate sculpture centrally but covered with strong transverse or arcuate wrinkles near sides and along anterior margin, anterior margin with V-shaped emargination; first abdominal ventrite covered with dense, longitudinal wrinkles and ocellate sculpture, remaining ventrites nearly uniformly with biarcuate or triarcuate sculpture; posterior margin of anal ventrite arcuately acuminate. Legs: Procoxa and mesocoxa globular, metacoxa expanded as a transverse plate and covered with ocellate sculpture; all trochanters small, nearly triangular; all femora moderately dilated; all tibiae slender with pale pubescence, row of soft brown-yellow spines along outer and inner sides; all tarsi light yellow; each claw with a swollen tooth at base. Sexual dimorphism: Male unknown.

Differential Diagnosis. This species resembles Trachys tsushimae Obenberger, 1922 , but can be separated as follows: 1) in T. scapulis the elytral humerus is very strongly expanded as a bump on each side, while in T. tsushimae the humerus is only moderately projecting; 2) in T. scapulis the lateral pronotal sides strongly taper from the base to the anterior angles, and the basal margin is 1.9 times as wide as the anterior margin in dorsal view, while in T. tsushimae the lateral pronotal sides only moderately taper to the anterior margin, and the basal margin is only 1.58 times as wide as the anterior margin; 3) in T. scapulis the median lobe of the basal margin is rather sharply produced posteriorly and rather acuminate apically, while in T. tsushimae it is only moderately produced posteriorly and only slightly angulate apically.

Etymology. The species name is derived directly from the Latin adjective “scapulis ”, meaning hunched, referring to the shape of the elytral humeri.