Trachys chalingensis Peng, 2022

Peng, Zhongliang, 2022, Studies on the Genus Trachys Fabricius from China (3) - A Faunal Survey of Hunan Province and Descriptions of Four New Species (Coleoptera: Buprestidae: Agrilinae: Tracheini), The Coleopterists Bulletin 76 (2), pp. 263-272 : 265-267

4. Trachys chalingensis Peng , new species zoobank.org/ urn:lsid:zoobank.org:act:7DD58C45-E186-4454-9D0E-F3B63B86B867 Figs. 2–4

Type Specimen. Holotype ( BPCQ), female, labeled: “Vil. Shanmuchong, 26°54′N, 113°52′E, altitude 800 m, Zhitang, Chaling, Hunan, 29-VII-2019, Leg. Z-L Peng ”.

Description. Habitus ( Fig. 2 ): Length 2.5 mm, width 1.7 mm; surface uniformly brown-crimson, underside also brown-crimson but with more bright reflections centrally; a very small but rather robust and ovate species. Head: Widely excavated between eyes; vertex transversely flattened, uniformly covered with distinct scale-like or ocellate sculpture, and nearly uniformly clothed with pale pubescence; frons depressed along midline with a longitudinal groove, irregularly punctate; eyes reniform; antennal sockets situated just above lower margins of eyes, wide and deep; clypeus golden bronze, metallic and shiny, nearly rectangular, both anterior margin and clypeal suture transversely straight, lateral sides slightly narrowed at midlength; antenna rather short, barely reaching anterior margin of pronotum when laid alongside; antennal scape and pedicel both moniliform, 1.50 times as long as wide; antennomeres 3 – 6 cylindrical, much shorter than antennal scape and pedicel and slightly shorter than remaining apical ones, 1.80 times as long as wide; antennomeres 7 – 11 serrate; lateral sides of head oblique from dorsal view, nearly on same bevel with lateral margins of pronotum. Pronotum: 2.8 times as wide as long, widest at base, basal margin 1.45 times as wide as anterior margin in dorsal view, much narrower than elytra at base and at elytral humeri; lateral margins very sharply tapering from base to acute anterior angles; anterior margin transversely elevated and smooth, biarcuate with median lobe markedly produced forwards; both inner and outer basal edges trisinuate, median lobe of inner basal edge angulate medially, but that of outer basal edge truncate, extent of margin between outer and inner edges wide and transversely equal; disc convex but slightly depressed along basal margin, surface uniformly covered with scale-like or ocellate sculpture, nearly uniformly clothed with pale pubescence mixed with very sparse brown-yellow setae, slightly glabrous centrally. Scutellar shield: Very small but clearly visible, triangular, smooth. Elytra: 1.42 times as long as wide, 4.25 times as long as pronotum, widest at humeri; lateral margins from base to posterior third nearly parallel, only slightly emarginate behind humeri, from posterior third gradually converging to apices; apices separately arcuate without distinct apical and lateral denticles; elytral surface slightly convex; humeri slightly projecting beyond elytral outline; basal depressions rather wide; entire surface nearly uniformly covered with longitudinally aligned foveae, nearly evenly but sparsely scattered with brown-yellow pubescence and pale pubescence, ornamentation consisting of dense pale pubescence on each elytron including one spot at base, another one under humerus, an indistinct obliquely zigzag band on basal half and two parallel zigzag bands on apical half. Lateral View ( Fig. 3 ): 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 angulate angle above metaventrite, humeral carina indistinct, with only an arcuate convex trace. Underside ( Fig. 4 ): Irregularly covered with short white pubescence, denser near sides; prosternal process about 1.6 times as long as wide, widest at apical angles; apical angles weakly acute, lateral margins narrowed at middle; apical margin rather arcuate, entire apical half dilated; surface sparsely scattered with a few pale setae; anterior part of prosternum transverse, narrow, anterior margin weakly trisinuate, posterior margin slightly obliquely arcuate on each side, lateral margins slightly oblique; hypomeron with a sub-reniform depressed marking near inner side; metaventrite rather smooth with indistinct sparse ocellate sculpture centrally but covered with strong reticulate wrinkles near sides and along anterior margin, anterior margin deeply emarginate; first abdominal ventrite covered with dense longitudinal and reticulate wrinkles, remaining ventrites smooth with indistinct ocellate 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 brown-yellow and soft 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 rather peculiar species only slightly resembles Trachys koshunensis Obenberger, 1940 , but can be distinguished from that and other similar species by its small size, its elytra with longitudinally aligned foveae, and its unique elytral ornamentation.

Etymology. The specific epithet refers to the locality Chaling County in eastern Hunan Province (Shanmuchong) where the holotype was collected.

Figures

Figs. 2–10. Holotypes of new species of Trachys. 2–4) T. chalingensis, new species, holotype, female: 2) Dorsal view; 3) Lateral view; 4) Ventral view. 5–7) T. cylindricus, new species, holotype, female: 5) Dorsal view; 6) Lateral view; 7) Ventral view. 8–11) T. latiquadratus, new species, holotype, male: 8) Dorsal view; 9) Lateral view; 10) Ventral view.