Trachys latipennis Peng, 2021

Trachys latipennis Peng , new species

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( Figs. 7 – 10 View Figs )

Type Specimen. Holotype ( BPCQ), male, genitalia dissected, mounted on cover slip and pinned with holotype, labeled: “ Mt. Meiling , 500 m, 28°79′N 115.75′E, Suburb of Nanchang, Jiangxi, China, 18-IX-2005, Leg. X-Q. Sheng ”.

Description. Habitus ( Fig. 7 View Figs ): Length 3.6 mm, width 2.1 mm; head and pronotum brown-purple, elytra dark purple; underside brown with purple reflections; a very wide and flattened species. Head: Widely excavated between eyes; vertex transversely flattened; frons deeply depressed centrally, irregularly covered with dense and recumbent dark-yellow pubescence; eyes reniform; antennal sockets situated above lower margins of eyes; clypeus bronze, metallic and shiny, with dense transverse micro-wrinkles; anterior margin deeply and semi-circularly emarginate, clypeal suture nearly straight, lateral sides narrowed at midlength; antennae very short, barely reaching anterior margin of pronotum when laid alongside; antennal scape cylindrical, about 1.52 times as long as wide; pedicel moniliform, nearly as long as wide; antennomeres 3 – 6 subcylindrical, 1.21 times as long as wide, much shorter than scape and pedicel and slightly shorter than remaining apical ones; antennomeres 7 – 11 serrate. Pronotum: About 2.8 times as wide as long, widest at base, nearly as wide as elytra at base but much narrower than at elytral humeri; lateral margins directly and sharply converging from base to acute anterior angles; anterior margin biarcuate with median lobe slightly anteriorly produced; basal margin trisinuate with angulate median lobe; disc convex medially, slightly depressed along basal margin; surface uniformly covered with scale-like sculpture and nearly evenly clothed with yellowish pubescence mixed with irregular white pubescent spots, slightly glabrous in middle. Scutellar shield: Very small but clearly visible, triangular, smooth. Elytra: 1.39 times as long as wide, 4.45 times as long as pronotum, widest at humeri; lateral margins slightly diverging from base to humeri, arcuately emarginate from humeri to midlength, then gradually and arcuately converging to apices; apices jointly arcuate without distinct apical and lateral denticles; elytral surface rather flattened; humeri strongly projecting beyond elytral outline; basal depressions indistinct; entire surface irregularly covered with rugae and foveae; ornamentation consisting of only bright white pubescence, arranged on each elytron as follows: irregular white pubescence at humeral depression, under humeri, and at basal third near suture, an oblique zigzag band at midlength, two parallel and transverse bands on posterior half, and pubescence near apex. Lateral view ( Fig. 8 View Figs ): Thickest point lying at basal third of elytra; maximal thickness greatly exceeding length of head plus pronotum, curvature with angle of about 120° between pronotal margin and subhumeral lobe; basal part of lateral elytral margin obliquely straight with obtuse angle above metaventrite; humeral carina indistinct with only an arcuate convex trace at base. Underside ( Fig. 9 View Figs ): Nearly uniformly covered with short, sparse, pale pubescence; anterior part of prosternum transverse; anterior margin transverse, posterior margin slightly oblique on each side, surface irregularly clothed with dense yellowish and pale pubescence; prosternal process long, widest at apical angles, basal margin distinct, gradually diverging from base to apical angles, apical margin arcuate, surface smooth with sparse pale and yellow pubescence; hypomeron with a footprint-like depressed marking on each side, covered with indistinct micro-wrinkles, a strong carina near side; metaventrite covered with ocellate sculpture centrally, with strong, dense wrinkles near sides and along anterior margin, anterior margin with deep V-shaped emargination; anterior two ventrites of abdomen covered with reticulate wrinkles and ocellate sculpture, remainder rather smooth with only indistinct ocellate sculpture; posterior margin of anal ventrite arcuate. Legs: Procoxa and mesocoxa small and 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 a row of soft brown-yellow spines along inner side; tarsi bright yellow; each claw with a swollen tooth at base. Aedeagus ( Fig. 10 View Figs ): Length 0.90 mm, width 0.4 mm; parameres mostly black-yellow, other areas brown-yellow; phallobase very narrow, handle-shaped, about 0.35 times the total length; basal knots indistinct; at base in middle with a large round hole; lateral sides of parameres slightly diverging from base to apical third, then strongly dilated, forming a sharp lateral angle of lobe on each side, from lobe angle very sharply tapering to apices; median lobe cylindrical, apex very sharp. Sexual dimorphism: Female unknown.

Differential Diagnosis. This species is close to Trachys aeneiceps Obenberger, 1929 ; however, it is wider and more ovate and more flattened, and the elytra in the anterior half are subparallel, while T. aeneiceps is more cylindrical and more robust, and the elytra in the anterior two-thirds are more attenuate. The shape of the prosternal process in the two species also is rather different; in T. latipennis the apical half is only slightly widened, while in T. aeneiceps the apical half is markedly dilated with the basal half very narrow and slender.

Etymology. The species name is derived from the Latin adjective “latipennis ”, meaning wide wing, referring to the wide elytra of this new species.