Trachys quadripennis Peng, 2021

Peng, Zhongliang, 2021, Studies on the Genus Trachys Fabricius from China (2) - Descriptions of Six New Species (Coleoptera: Buprestidae: Agrilinae: Tracheini), The Coleopterists Bulletin 75 (4), pp. 749-757 : 755-756

Trachys quadripennis Peng , new species

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( Figs. 15–18 )

Type Specimen. Holotype ( BPCQ), male, genitalia dissected, mounted on cover slip, and pinned with holotype, labeled: “Zuojiang, altitude 143 m, 22°19′N 107.08′E, Ningming , Guangxi, China, 21-VII-2019, Leg. Yongyi Yuan ”.

Description. Habitus ( Fig. 15 ): Length 2.8 mm, width 1.6 mm; surface uniformly bronze-brown, underside brown with bronze reflections; form very broad and rather quadrate. Head: Widely excavated between eyes; vertex transversely flattened, uniformly covered with dense brown-yellow pubescence with four transversely arranged white pubescent spots; frons depressed along midline, covered with dense, recumbent, brown-yellow pubescence; eyes reniform, genae very short; antennal sockets situated just above lower margins of eyes; clypeus bronze, metallic and shiny; anterior margin widely and deeply emarginate; clypeal suture nearly straight; lateral sides narrowed at midlength; antennae relatively long, reaching slightly past anterior margin of pronotum when laid alongside; antennal scape and pedicel cylindrical, 1.20 times as long as wide; antennomeres 3 – 6 cylindrical, much shorter than scape and pedicel and slightly shorter than remaining apical ones, 1.50 times as long as wide; antennomeres 7 – 11 serrate. Pronotum: 2.95 times as wide as long, widest at base, slightly wider than elytra at base but much narrower than at elytral humeri; lateral margins slightly diverging from base to basal third, then sharply converging to anterior angles; anterior margin semi-rounded without distinct median lobe; both inner and outer basal edges trisinuate, with angulate median lobe; extent of basal margin between outer and inner edges wide and transversely equal; disc convex medially, slightly depressed along basal margin; surface uniformly covered with ocellate sculpture, nearly uniformly clothed with brown-yellow pubescence mixed with nine irregular spots of white pubescence. Scutellar shield: Very small but clearly visible, triangular, smooth. Elytra: 1.30 times as long as wide, 3.90 times as long as pronotum, widest at humeri; anterior two-thirds of elytra rather quadrate; lateral margins slightly diverging from base to humeri, deeply emarginate from humeri to posterior third, then gradually and arcuately converging to apices; apices jointly arcuate without distinct apical and lateral denticles; elytral surface broad, slightly convex; humeri distinctly projecting beyond elytral outline; basal depressions indistinct; entire surface nearly uniformly clothed with brown-yellow pubescence mixed with white pubescent markings but with a transverse glabrous band at posterior third, wider near suture; ornamentation consisting of white pubescence arranged on each elytron as follows: three spots in basal third, an oblique zigzag band at midlength, two transverse bands on posterior half, first one zigzag, apical one transverse. Lateral view ( Fig. 17 ): Thickest point lying at basal third of elytra; maximal thickness slightly exceeding length of head plus pronotum; 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 short, arcuate but rather weak. Underside ( Fig. 16 ): Nearly uniformly covered with short, pale pubescence; prosternal process 1.48 times as long as wide, widest at apical angles; lateral sides parallel in basal half, gradually diverging from midlength to apical angles; apical margin arcuate; surface slightly depressed, smooth, with dense and long, pale pubescence; anterior part of prosternum transverse, narrow, anterior margin slightly emarginate, lateral sides slightly oblique, posterior margin transversely oblique laterally; surface clothed with dense pale and brown-yellow pubescence; hypomeron with a reniform depressed marking on each side, covered with dense micro-wrinkles; metaventrite smooth centrally with ocellate sculpture, near sides with strong reticulate wrinkles, near anterior margin with two arcuate grooves on each side, anterior margin with V-shaped emargination; anterior two abdominal ventrites uniformly and densely covered with round or ocellate sculpture, remaining ventrites rather smooth, ocellate sculpture indistinct; posterior margin of anal ventrite arcuate. Legs: Procoxa and mesocoxa globular, metacoxa expanded as a transverse plate and covered with round ocellate sculpture; all trochanters small, nearly triangular; all femora moderately dilated; all tibiae slender with pale pubescence and soft yellow spines along inner sides; all tarsi bright yellow; each claw with a short, swollen tooth at base. Aedeagus ( Fig. 18 ): Length 0.70 mm, width 0.20 mm; entirely yellow-brown; phallobase long, about 0.4 times the total length; basal knots small or inconspicuous; basal lobe greatly prolonged posteriorly; lateral sides of parameres gradually diverging from base to apical fifth, then very sharply tapering to apices, median lobe cylindrical, rather swollen and acuminate apically. Sexual dimorphism: Female unknown.

Differential Diagnosis. This species is very similar to Trachys taiwanensis Obenberger, 1929 , but differs in that the elytra are wider, more quadrate, and nearly uniformly covered with dense brown-yellow pubescence, while in T. taiwanensis the elytra are narrower, more attenuate posteriorly, and covered with only sparse brown-yellow pubescence.The prosternal processes of the two species are also rather different; in T. quadripennis the prosternal process diverges laterally in the apical half and the apical margin is arcuate, while in T. taiwanensis the entire lateral sides are subparallel and the apical margin is rather angulate.

Etymology. The species name is an adjective derived from two Latin words, “quadratus” meaning square or quadrate, and “pennis” meaning wing, referring to the elytral shape of the new species.

Figures

Figs. 13–21. Holotypes of new species of Trachys. T. aureolus, new species, holotype, male: 13) Lateral view; 14) Aedeagus (dorsal view). T. quadripennis, new species, holotype, male: 15) Dorsal view; 16) Ventral view; 17) Lateral view; 18) Aedeagus (dorsal view). T. scapulis, new species, holotype, female: 19) Dorsal view; 20) Lateral view; 21) Ventral view.