Adiscus bimaculicollis Chen & Pu, 1980

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 : 23-25

Adiscus bimaculicollis Chen & Pu, 1980

(Figs 8-1; 8-2)

Adiscus bimaculicollis Chen & Pu, 1980: 110 (type locality: Yunnan; type deposited: IZ-CAS); Schöller et al., 2010: 607 (catalogue).

Material examined. CHINA: Holotype: female, “ Yunnan, Jinping River, Dongzhai [ Chinese letters] / 1500–1700 m // Chinese Academy of Sciences [ Chinese letters] / 11. VI. 1956 / coll. Keren Huang leg. [Chinese letters] // HOLOTYPE ”. ( IZ-CAS).

Redescription. Measurements. Female. BL = 3.94 mm, BW = 2.78 mm, HL = 1.28 mm, HW = 1.22 mm, PL = 1.17 mm, PW = 2.42 mm, PA = 80°, EL = 2.75 mm, EA = 160°.

Body (Figs. 8-1A; 8-2A) ovate, dorsum strongly convex, basic color reddish brown. Antennomeres 1–5 pale brown, 6–11 darkish brown. Pronotum with two transverse-ovate black patches at each side,near but not reaching anterior margin, their combined width about 2/3 as broad as basal margin; posterior margin black. Elytra with two transverse broad irregularly shaped black bands, one at base, extending from lateral margin to suture, with lateral edge reaching basal 1/3 of elytra and inner edge reaching about middle of suture, posterior edge irregular; apical band extending from near lateral margin of elytra to first puncture row, like two black ovals combined, inner longer than outer. Reddish brown on legs, propleura, mesopleura, apical region of Mesoventrite. Venter black, and the apical region of pygidium with a broad black spot.

Head rugose, coarsely and rather closely punctate, middle region slightly concave. Eyes reniform, superior eyelobes separated by slightly greater distance than antennal insertions. Clypeus not distinctly separated from frons, anterior margin arched and emarginated. Antennae moderately short, reaching shoulder region of elytra; scape clubbed, pedicel oblong, about half as long as scape, antennomeres 3 and 4 slender, about equal in length, slightly longer than pedicel; 6–11 broadened but not flattened, each segment obviously longer than wide.

Pronotum (Figs. 8-1A; 8-2A) convex, much broader basely than apically, basal width about twice as long as pronotal length. Anterior margin nearly straight. Posterior margin sinuate with fine serration, and produced into an acute angle of about 80° at middle. Disc with both kinds of coarse and fine punctures, but coarse ones sparse; punctures on black spots slightly denser and more obvious; fine punctures extremely small and dense.

Elytra (Figs. 8-1A; 8-2A) with humeri prominent and glabrous, as long as wide. Disc with regular striae, more coarsely punctured than pronotum, intervals with scattered minute punctures. Epipleural lobe (Fig. 8-2B) weak, lateral margins slightly expanded ventrally and with weakly arcuate lobe at basal 1/4 of elytron, with both lobe sides forming angle of 160°, epipleura visible in lateral view.

Venter clothed with sparse and short pubescence. Prosternum (Fig. 8-2C) trapezoidal, anterior margin not prominent, lateral ridge elevated slightly, posterior margin weakly undulated. Mesoventrite broad, 2.5 times as broad as long. Pygidium with dense coarse punctures.

Distribution. China (Yunnan).

Diagnosis. This species is similar to A. maculatus and A. kweiyangensis . The main difference is that A.bimaculicollis has the black markings of dorsum much larger, the terminal segments of antennae slightly flattened, the lateral ridges of prosternum not as strongly raised, and the epipleural lobe of elytra slightly prominent and weakly arc-shaped.