Trachys latiquadratus 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 : 268-270

12. Trachys latiquadratus Peng , new species zoobank.org/ urn:lsid:zoobank.org:act:916345A7-8C43-4BEC-8AE7-352248F5F314 Figs. 8–11

Type Specimens. Holotype ( BPCQ), male, genitalia dissected, mounted on cover slip, and pinned with holotype, labeled: “ Mt. Xiabafengshan, 29°58′N, 110°43′E, altitude 700 m, Hupingshan, Shimen , Hunan, 20-VII-2019, Leg. Z-L Peng et Y-Q Cai ” . Paratype ( ZLPN), female, labeled: “Vil. Dimiao, 26°31′N, 109°25′E, altitude 660 m, Sanqiao , Jingzhou , Hunan, China, 30-IX-2021, Leg. X-Q Sheng et Z-L Peng ” .

Description. Habitus ( Fig. 8 ): Length 3.2 mm, width 2.0 mm; head and pronotum dark brown with slightly but uniformly golden reflections, elytra dark brown with partial golden reflections, underside uniformly brown with stronger and uniformly golden reflections; a very wide and rather square species. Head: Very short, widely excavated between eyes; vertex rather flattened and transversely convex, uniformly covered with scale-like or ocellate sculpture and brown-yellow pubescence; frons deeply and widely depressed along midline, densely covered with recumbent brown-yellow pubescence; eyes reniform; antennal sockets situated just above lower margins of eyes, wide and deep; clypeus golden bronze, metallic and shiny; anterior margin transversely straight, clypeal suture arcuately emarginate, lateral sides narrowed at midlength; antenna long, reaching past anterior margin of pronotum when laid alongside; antennal scape and pedicel both moniliform, 1.20 times as long as wide; antennomeres 3–6 cylindrical, much shorter than antennal scape and pedicel and slightly shorter than remaining apical ones, 1.50 times as long as wide; antennomeres 7–11 serrate; lateral sides of head oblique from dorsal view, but not on same bevel with lateral margins of pronotum, head at base much narrower than anterior margin of pronotum. Pronotum: About 3.05 times as wide as long, widest at base, basal margin 1.55 times as wide as anterior margin in dorsal view, slightly narrower than elytra at base, but much narrower than at elytral humeri; lateral margins obliquely tapering from base to acute anterior angles; anterior margin slightly elevated, biarcuate with slightly produced median lobe; both basal inner and outer edges trisinuate, both with median lobe arcuately produced posteriorly, extent of margin between outer and inner edges transversely equal but rather narrow or indistinct; disc more or less convex but slightly depressed along basal margin, surface uniformly covered with distinct scale-like or ocellate sculpture, uniformly clothed with brown-yellow pubescence except four round markings with sparse black pubescence, ornamentation of white pubescence including five longitudinal stripes, middle three longer but all not reaching base of pronotum. Scutellar shield: Very small but clearly visible, triangular, glabrous and smooth. Elytra: 1.30 times as long as wide, about 4.25 times as long as pronotum, widest at humeri; lateral margins slightly diverging from base to humeri, from humeri to posterior 1/4 nearly parallel, anterior 4/5 very quadrate, then arcuately converging to apices; apices jointly arcuate without distinct apical and lateral denticles; elytral surface very wide and flattened; basal depressions wide; humeri only slightly projecting beyond outline of elytra; elytral surface nearly evenly covered with black pubescence and irregularly clothed with brown-yellow setae, ornamentation consisting of white pubescence, arranged on each elytron as follows: a spot at base near suture, an oblique strip from humerus extending to middle of basal third, a zigzag transverse band at midlength on basal half, two parallel zigzag transverse bands in apical half, and some extra pubescence near apex. Lateral View ( Fig. 9 ): Thickest point lying at basal third of elytra; maximal thickness greatly exceeding length of pronotum plus head; curvature with angle of 110° between pronotal margin and subhumeral lobe; basal part of elytral margin rather obliquely straight with obtuse angle above metaventrite, humeral carina indistinct, with only an arcuate convex trace. Underside ( Fig. 10 ): Nearly uniformly covered with short and recumbent yellow-pale pubescence; prosternal process about 1.60 times as long as wide, widest at apical angles; apical angles arcuate, lateral margins arcuately narrowed at middle, apical margin weakly acuminate apically; surface smooth, densely clothed with long pale-yellow pubescence; anterior part of prosternum butterfly-shaped; anterior margin broadly and arcuately emarginate at middle, posterior margin oblique on each side; hypomeron with a reniform depressed marking near inner side, outer side quite smooth; metaventrite covered with sparse, coarse foveae, near sides with dense, strong arcuate or reticulate wrinkles; anterior margin with a deep V-shaped emargination; first abdominal ventrite covered with dense, strong arcuate or ocellate sculpture, remaining ventrites rather smooth with indistinct arcuate or ocellate sculpture; posterior margin of anal ventrite arcuately acuminate apically. 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, soft spines along outer and inner sides; all tarsi light yellow; each claw with an obtuse tooth at base. Aedeagus ( Fig. 11 ): Length 1.1 mm, width 0.3 mm; brown-yellow but along sides more dark; phallobase narrow, much narrower than base of parameres, about 0.3 times the total length of aedeagus, basal knots small and slightly darkened; tegminal strut moderate; parameres gradually diverging from base to subapices, then sharply tapering to apices; median lobe very wide, slightly longer than tegmen, basal two thirds nearly parallel, from apical third generally converging to apex, but in subapex slightly emarginate. SeXual dimorphism: Female much larger, lateral sides of pronotum more sharply attenuate anteriorly.

Differential Diagnosis. This species resembles T. arhema , but it is much wider and more quadrate, and the lateral sides of elytra are rather parallel in the anterior 3/4, while in T. arhema these are parallel only in the anterior 2/3; the prosternal processes for the species are different, with that of T. latiquadratus narrowed at middle, while the lateral sides of that of T. arhema are rather parallel in the basal two-thirds; the pubescent ornamentation on the pronotum and elytra for each species is quite different.

Etymology. The species name is derived from the two Latin adjectives “latitudo” meaning “wide” and “quadrata” meaning “square”, referring to the adult body shape of the 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.

Figs. 11–14. 11) Trachys latiquadratus, new species, aedeagus (fully dissected). 12–14) T. scapuliformis, new species, holotype, female: 12) Dorsal view; 13) Lateral view; 14) Ventral view.