Adiscus yunnanus Medvedev, 2008

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 : 77

Adiscus yunnanus Medvedev, 2008

(Figs 32-1; 32-2)

Adiscus yunnanus Medvedev, 2008: 205 (type locality: Yunnan; type deposited: NHMB).

Material examined. China: Holotype: 1 male, “ Yunnan: Lijiang / 2600 m / 30. VI–2. VII. 1960 / coll. L. M. Bocak leg. // HOLOTYPE ”. ( ZIN).

Redescription. Measurements. Male. BL = 2.91 mm, BW = 1.96 mm, HL = 1.05 mm, HW = 0.95 mm, PL = 1.01 mm, PW = 2.05 mm, PA = 110°, EL = 2.20 mm, EA = 120°, AL = 0.97 mm, AW = 0.33 mm.

Body (Fig. 32-A) ovate, dorsum mostly yellowish brown. Head black; antennomeres 1–4 piceous, 5–11 brown; frons and vertex black. Pronotum fulvous, basal margin black. Elytra pale fulvous, basal region and suture black; with four large black spots; two near the suture, anterior dumbell-shaped, posterior oblong; two laterally, anterior oblong, along the anterior margin, posterior oblong, and larger.

Head shiny; densely punctate, partly strigose on frons. Eyes reniform; superior eye-lobes separated and wider than antennal insertions. Anterior margin of clypeus straight. Antennae short, reaching base of pronotum, scape swollen, clubbed, pedicel minute, about as half as the scape, apical 6 segments broad, about 1.6 times as long as wide.

Pronotum (Fig. 32-A) convex and shiny, base much broader than apex, basal width about 2.0 times of pronotal length. Anterior margin nearly straight. Posterior margin sinuate with fine serration, and produced into an obtuse angle of about 110° at middle. Disc evenly convex, impunctate.

Elytra (Fig. 32-A) as broad as long, humeri slightly prominent. Disc finely punctate, with 11 regular striae; intervals flat, except two outermost, with scattered minute punctures and microscopically transverse striation. Lateral margins distinctly expanded ventrally with rounded lobe at basal 1/4 of elytron, with both lobe sides forming angle of 120°, epipleura weak, obliquely placed and visible in lateral view.

Venter clothed with pubescence. Prosternum trapezoidal, lateral ridge sharply and arcuately elevated, posterior margin nearly straight. Mesoventrite broad, twice as wide as long. The first segment of fore and mid tarsi broadened in male. Pygidium with dense punctures.

Aedeagus. (Figs. 32-1C–D; 32-2C–D) Median lobe elongate, about 2.8 times as long as wide, nearly parallelsided. Apex of median lobe slightly narrower than middle, acute at apex, moderately curved in lateral view; with several setae on each side of apex, sparsely punctate on ventral side of distal part. Median orifice with median sclerite bending inwards above surface. Inner sac rather round, dilated at apex nearly round, but bilobed and acute at base, base slightly narrow. Tegmen Y-shaped, weakly sclerotized, almost translucent.

Distribution. China (Yunnan).

Diagnosis. This species is similar to A. occipitalis , but the latter has fine and dense punctures on pronotum, its elytra with epipleura hardly visible in lateral view, and venter is yellowish brown.