Trachys cylindricus 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 : 267-268

5. Trachys cylindricus Peng , new species zoobank.org/ urn:lsid:zoobank.org:act:3795675F-BA62-4CC1-9E97-358AADA5D055 Figs. 5–7

Type Specimen. Holotype ( BPCQ), female, labeled: “ Xiabafengshan (Mt.), Hupingshan, Shimen , Hunan, 29°58′N, 110°43′E, altitude 700 m, 20-VII-2019, Leg. Z-L Peng et Y-Q Cai”.

Description. Habitus ( Fig. 5 ): Length 2.9 mm, width 1.5 mm; surface uniformly black-brown with slightly crimson reflections, underside also black-brown but with brighter crimson reflections centrally; a rather long and cylindrical species. Head: Very short, widely and deeply excavated between eyes; vertex narrowed and transversely flattened, uniformly clothed with pale pubescence; frons widely depressed along midline, irregularly punctate, covered with a few recumbent pale setae, but centrally glabrous; eyes reniform; antennal sockets situated just above lower margins of eyes, wide and deep; clypeus golden bronze, metallic and shiny, nearly rectangular, anterior margin arcuately emarginate and clypeal suture nearly transversely straight, lateral sides slightly narrowed at midlength; antennae reaching past 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 smaller than antennal scape and pedicel and slightly smaller than remaining apical ones, 1.80 times as long as wide; antennomeres 7 – 11 serrate; lateral sides of head slightly oblique from dorsal view, head at base much narrower than anterior margin of pronotum. Pronotum: About 2.85 times as wide as long, widest at base, basal margin 1.50 times as wide as anterior margin in dorsal view, slightly narrower than elytra at base and much narrower than elytra at humeri; lateral margins arcuately tapering from base to acute anterior angles; anterior margin slightly transversely elevated and smooth, biarcuate with angularly produced median lobe; both inner and outer basal edges trisinuate, top of median lobe of both inner and outer basal edges truncate, extent of margin between outer and inner edges very narrow but transversely equal; disc convex but slightly depressed along basal margin, surface uniformly covered with scale-like or ocellate sculpture, densely clothed with white pubescence mixed with very few brown-yellow setae, either side of median line slightly glabrous. Scutellar shield: Very small but clearly visible, triangular, smooth. Elytra: 1.55 times as long as wide, about 4.75 times as long as pronotum, widest at humeri; lateral margins from base diverging to humeri, from humeri obliquely tapering to posterior third, gradually converging to sub-apices and arcuately to apices; apices jointly arcuate without distinct apical and lateral denticles; elytral surface rather convex; humeri strongly projecting beyond elytral outline; basal depressions indistinct; entire surface nearly uniformly covered with round foveae, nearly evenly but sparsely scattered with brown-yellow pubescence, ornamentation consisting of dense pale pubescence on each elytron including one spot at base, one under humerus, an indistinct and obliquely zigzag band at midlength, two parallel zigzag bands on apical half, and a short transverse band near apex. Lateral View ( Fig. 6 ): Thickest point lying behind scutellar shield; maximal thickness slightly exceeding length of pronotum plus head; curvature with angle of 100° between pronotal margin and subhumeral lobe; basal part of elytral margin obliquely straight with angulate angle above metaventrite, humeral carina rather obliquely straight at base, then arcuate to basal third of elytra. Underside ( Fig. 7 ): Nearly uniformly covered with short white pubescence, denser near posterior margin of each abdominal ventrite; prosternal process about 1.75 times as long as wide, widest at apical angles; apical angles angulate, lateral margins arcuate, narrowed at middle; apical margin rather weakly angulate; surface smooth, sparsely scattered with a few pale setae; anterior part of prosternum butterfly-shaped; anterior margin slightly trisinuate, posterior margin arcuately oblique on each side; surface smooth with sparse, pale pubescence; hypomeron with a semilunar depressed marking near inner side; metaventrite rather smooth with distinct and ocellate foveae centrally but covered with strong oblique or arcuate wrinkles near sides and along anterior margin, anterior margin widely and deeply emarginate; first abdominal ventrite covered with dense longitudinally-aligned reticulate wrinkles, remaining ventrites smooth with indistinct ocellate sculpture, posterior margin of anal ventrite arcuate. Legs: Procoxa and mesocoxa globular, metacoxa expanded as a transverse plate and covered with ocellate sculpture and dense, pale pubescence; 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 species is rather unique, and it only slightly resembles Trachys reitteri Obenberger, 1930 , but it can be easily distinguished from T. reitteri for its much longer and much more cylindrical shape, and its prosternal process with narrowed lateral margins at middle, while T. reitteri is much wider and more flattened in shape, and its prosternal process has parallel lateral margins.

Etymology. The species name is derived directly from the Latin adjective “cylindrica”, meaning cylindrical, referring to the adult body shape of the new species.

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.