Adiscus maculatus ( Weise, 1912 )

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 : 48-51

Adiscus maculatus ( Weise, 1912)

(Figs 20-1; 20-2)

Dioryctus maculatus Weise, 1912: 80 (type locality: Yunnan; type deposited: MNHN).

Adiscus maculatus: Gressitt & Kimoto, 1961: 118 ; Tan et al., 1980: 170; Schöller et al., 2010: 608 (catalogue). = Dioryctus multimaculatus Pic, 1935: 19 (type locality: China; type deposited: MNHN).

= Adiscus multimaculatus: Gressitt & Kimoto, 1961: 118 (as synonym of Adiscus maculatus ).

= Adiscus maculatithorax sensu Tan, 1992b: 783 , nec Pic, 1927.

Material examined. CHINA: Yunnan Province: 2 males, Kunming, 31. V. 1931, coll. unknown ( IZ-CAS) ; 1 female, Dali, 31. VI. 1955, coll. Chongle Liu ( IZ-CAS) .

Redescription. Measurements. Males. BL = 3.65–3.94 mm, BW = 2.34–2.78 mm, HL = 1.21 mm, HW = 1.07 mm, PL = 1.20 mm, PW = 2.43 mm, PA = 105°, EL = 2.97 mm, EA = 150°, AL = 1.77 mm, AW = 0.66 mm.

Female. BL = 4.22 mm, BW = 2.86 mm, HL = 1.31 mm, HW = 1.16 mm, PL = 1.30 mm, PW = 2.64 mm, PA = 105°, EL = 3.22 mm, EA = 150°, SL = 0.77 mm.

Body (Figs. 20-1A; 20-2A) broadly ovate, reddish brown. Head reddish brown; mandibles black; labrum and antennae tinged with yellow. Pronotum reddish brown, basal margin black; sometimes basal part with two triangular black marks, fused with basal margin. Elytra reddish brown, basal margin and middle of suture black, and black margin of middle suture broadened from middle, disc with four black spots, basal pair always separate, while apical pair sometimes connected. Legs and prosternum yellowish brown, claws black. Venter black or sometimes reddish brown.

Head dull, densely and coarsely punctate, frons partly strigose. Eyes reniform; superior eye-lobes separated by same distance as antennal insertions. Clypeus densely granulose and finely punctate, anterior margin arched and emarginated apically. Antennae reaching elytral humeri; scape broadened, clubbed, pedicel shortly cylindrical, antennomeres 3 and 4 slender, 5 slightly broader, 3–5 about equal in length, 6–11 somewhat broadened and flattened, each segment about equal in length, the last segment pointed apically.

Pronotum (Figs. 20-1A; 20-2A) convex, base much broader than apex, basal width about twice as long as pronotal length. Anterior margin nearly straight. Posterior margin undulated, and produced into an obtuse angle of about 105° at middle. Disc evenly convex, finely and rather closely punctured, with smooth narrow interspaces.

Elytra (Figs. 20-1A; 20-2A) as broad as prothorax at base, subrectangular, humeri a little prominent. Disc slightly coarsely punctate, with 11 regular striae, row intervals with scattered minute punctures, puncture striae irregular on apical slope. Epipleural lobe (Fig. 20-2B) moderately large, lateral margins distinctly expanded ventrally with rounded lobe at basal 1/3 of elytron, with both lobe sides forming angle of 150°, epipleura obliquely placed and visible in lateral view.

Venter clothed with shortly silvery pubescence and fine punctures. Prosternum (Fig. 20-2C) trapezoidal, the lateral ridge distinctly and triangularly protruding, posterior margin nearly straight, Pygidium with coarse punctures and short fine pubescence.

Aedeagus. (Figs. 20-1D–F; 20-2D–F) Median lobe elongate, about 3 times as long as wide, parallel-sided. Apex of median lobe slightly narrower than middle, acute at apex, narrowly rounded, 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 slightly slender, bell-shaped, base with three lobes and slightly prominent, apex narrow and anterior margin nearly straight. Tegmen Y-shaped, weakly sclerotized, almost translucent.

Female. Body more robust than male, apical hollow in ventrite 5 deep and round. Spermatheca (Figs. 20-1C; 20-2G) s-shaped, acute-angled bending from base 1/3 and then bending in opposite direction from apex 1/3, weakly acute at apex; duct weakly sclerotized, irregularly coiled. Rectal sclerites (Fig. 20-1G) strongly sclerotized, not connected between two clubbed sclerites on ventral side.

Distribution. China (Yunnan); Vietnam.