Adiscus grandipalpus Tan, 1992

Duan, Wen-Yuan & Zhou, Hong-Zhang, 2022, Revision of the genus Adiscus Gistel, 1857 (Coleoptera: Chrysomelidae, Cryptocephalinae) from mainland China, Zootaxa 5096 (1), pp. 1-80 : 37-38

Adiscus grandipalpus Tan, 1992

(Figs 15-1; 15-2)

Adiscus grandipalpus Tan, 1992a: 602 (type locality: Hunan; type deposited: IZ-CAS); Schöller et al., 2010: 607 (catalogue).

Material examined. CHINA: Holotype: male, “ Hunan: Mt.Huping [Hupingshan] [ Chinese letters] / 800 m / Chinese Academy of Sciences [ Chinese letters] // 22. VI. 1987 / coll. Guangchun Lei [Chinese letters] // HOLOTYPE ”. ( IZ-CAS) ; Paratype: 1 male, same data as holotype .

Redescription. Measurements. Males. BL = 1.98–2.33 mm, BW = 1.36–1.63 mm, HL = 0.73 mm, HW = 0.76 mm, PL = 0.72 mm, PW = 1.35 mm, PA = 125°, EL = 1.57 mm, EA = 150°, AL = 1.21 mm, AW = 0.24 mm.

Body (Figs. 15-1A; 15-2A) small, ovate; mostly black. Head dark reddish brown, except vertex black; mouthparts yellowish; antennae yellowish brown, base of terminal segment fuscous; legs yellowish brown. Venter dark brown.

Head dull and smooth; finely and sparsely punctate. Eyes distinct, reniform; inner margin slightly emarginated; superior eye-lobes separated wider than antennal insertions. The anterior part of clypeus with punctures, slightly denser than those on head. Antennae slightly short, reaching elytral humeri, scape strongly swollen, pedicel subspherical and small, antennomeres 3–5 slender, almost as long as pedicel, 6–11 somewhat thickened, terminal segment about as long as scape.

Pronotum (Figs. 15-1A; 15-2A) convex, and broad, base much broader than apex, basal width about 1.9 times as long as pronotal length. Anterior margin nearly straight. Posterior margin sinuate with fine serration, and its middle portion produced into an obtuse angle of about 125°. Disc evenly convex, impunctate.

Elytra (Figs. 15-1A; 15-2A) as broad as pronotum at base, humeri somewhat prominent, glabrous. Disc sparsely and finely punctate, with 11 regular striae, without distinct minute punctures between rows. Epipleural lobe (Fig. 15-2B) weak, lateral margins weakly expanded ventrally and with fine lobe at basal 1/4 of elytron, with both lobe sides forming angle of 150°, epipleura obliquely placed and visible in lateral view.

Venter clothed with short pubescence and fine punctures. Prosternum (Fig. 15-2C) transverse, subquadrate, both sides weakly elevated into a low longitudinal ridge. Mesoventrite twice as wide as long, hind angles protruded.

Aedeagus. (Figs. 15-1C–E; 15-2D–F) Median lobe elongate, about 3 times as long as wide. Apex of median lobe slightly narrower than middle, acute at apex, moderately curved in lateral view; with several small setae on each side of apex, impunctate on ventral side. Median orifice with median sclerite bending inwards below surface. Inner sac slightly narrow, bell-shaped, dilated at apical 1/3, and strongly narrow at basal 1/4, but rounded and acute at apex. Tegmen Y-shaped, weakly sclerotized, almost translucent.

Distribution. China (Hunan).

Diagnosis. This species is similar to A. niger in body color, but distinguished by the strongly developed terminal segment of maxillary and labial palpi; head with fine punctures, impunctate pronotum and finely punctured elytra.