Adiscus speciosus Tan, 1988

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 : 68-71

Adiscus speciosus Tan, 1988

(Figs 28-1; 28-2)

Adiscus speciosus Tan, 1988: 319 (type locality: Xizang; type deposited: IZ-CAS); Schöller et al., 2010: 608 (catalogue).

Material examined. CHINA: Holotype: female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 24. IX. 1982 / coll. Yinheng Han [Chinese letters] // HOLOTYPE ”. ( IZ-CAS) ; Paratypes: 1 male, 1 female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 12. IX. 1982 / coll. Yinheng Han [Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 2 males, 1 female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 23. IX. 1982 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 6 males, 11 females, same as holotype; 1 female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 24–25. IX. 1982 / coll. Zaicai Lin [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 5 males, 4 females, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 26. IX. 1982 / coll. Zaicai Lin [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 27. IX. 1982 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 1. X. 1982 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 6. X. 1982 / coll. Zaicai Lin [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 male, 3 females, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 8. X. 1982 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 female, “ Tibet: Moto, Gedang [Chinese letters] / 2000 m / Chinese Academy of Sciences [ Chinese letters] // 14. X. 1982 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 3 females, “ Tibet: Moto, Gejia, Lasa [Chinese letters] / Chinese Academy of Sciences [ Chinese letters] // 10. XI. 1982 / coll. Zaicai Lin [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 male, 6 females, “ Tibet: Bomi [Chinese letters] / Chinese Academy of Sciences [ Chinese letters] // 1982 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 male, “ Tibet: Bomi, Yigong [Chinese letters] / 2300 m / Chinese Academy of Sciences [ Chinese letters] // 16. VIII. 1983 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 male, “ Tibet: Bomi, Yigong [Chinese letters] / 2300 m / Chinese Academy of Sciences [ Chinese letters] // 23. VIII. 1983 / coll. Zaicai Lin [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 2 males, 1 female, “ Tibet: Bomi, Yigong [Chinese letters] / 2300 m / Chinese Academy of Sciences [ Chinese letters] // 23. VIII. 1983 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 male, 2 females, “ Tibet: Bomi, Yigong [Chinese letters] / 2300 m / Chinese Academy of Sciences [ Chinese letters] // 23. VIII. 1983 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 male, 3 females, “ Tibet: Bomi, Yigong [Chinese letters] / 2300 m / Chinese Academy of Sciences [ Chinese letters] // 23. VIII. 1983 / coll. Zaicai Lin [ Chinese letters] // PARATYPE ”. ( IZ-CAS) ; 1 male, “ Tibet: Bomi, Yigong [Chinese letters] / 2300 m / Chinese Academy of Sciences [ Chinese letters] // 26. VIII. 1983 / coll. Yinheng Han [ Chinese letters] // PARATYPE ”. ( IZ-CAS) .

Redescription. Measurements. Males. BL = 3.05–3.46 mm, BW = 2.14–2.56 mm, HL = 0.85 mm, HW = 0.85 mm, PL = 0.92 mm, PW = 2.03 mm, PA = 100°, EL = 2.59 mm, EA = 130°, AL = 1.41 mm, AW = 0.49 mm.

Females. BL = 3.38–3.65 mm, BW = 2.42–2.68 mm, HL = 0.93 mm, HW = 0.94 mm, PL = 1.00 mm, PW = 2.20 mm, PA = 100°, EL = 2.81 mm, EA = 130°, SL = 0.51mm.

Body (Figs. 28-1A; 28-2A) round; dorsum strongly convex, mostly ochraceous. Head pale ochraceous; antennomeres 1–5 or 1–6 fulvous, the rest darkish brown. Pronotum ochraceous, tinged with darkish brown, the longitudinal ridge of prosternum piceous. Elytra reddish brown, with black markings, variegated. Venter reddish or yellowish brown.

Head dull; finely and slightly sparsely punctate. Eyes reniform, superior eye-lobes separated by greater distance than antennal insertions. Clypeus densely granulose and sparsely punctured, with an arcuate line in the basal region of antennae, separated from vertex. Antennae reaching elytral humeri, scape clubbed, pedicel oblong, about half as long as scape, antennomeres 3 and 4 slender, about as long as pedicel; base of 5 thin, the apex slightly broad, weakly longer than 4; 6–11 somewhat broadened.

Pronotum (Figs. 28-1A; 28-2A) convex, base much broader than apex, basal width about twice pronotal length. Anterior margin nearly straight. Posterior margin weakly sinuate with fine serration, and produced into an obtuse angle of about 100° at middle. Disc evenly convex, finely and rather closely punctures.

Elytra (Figs. 28-1A; 28-2A) as broad as prothorax at base, humeri somewhat prominent, glabrous. Disc punctate, with 11 regular striae, with scutellar striole indistinct, intervals with scattered minute punctures, puncture striae irregular and coarser on apical slope. Epipleural lobe (Fig. 28-2B) large, lateral margins distinctly expanded ventrally with rounded lobe at basal 1/4 of elytron, with both lobe sides forming angle about 130°, visible in lateral view.

Venter clothed with pubescence. Prosternum (Fig. 28-2C) subquadrate, slightly narrowed anteriorly, lateral ridge strongly elevated, triangular in lateral view, posterior margin nearly straight. Mesoventrite rectangular, posterior margin slightly arcuate concave. Pygidium with dense punctures and short pubescence.

Aedeagus. (Figs 28-1D–F; 28-2D–F) Median lobe elongate, about 2.8 times as long as wide, nearly parallelsided. Apex of median lobe slightly narrower than middle, acute at apex, strongly curved in lateral view; with several setae on each side of apex, impunctate on ventral side of distal part. Median orifice with median sclerite bending inwards above surface. Inner sac rather narrow, about 3 times as long as wide, cylindrical, slightly twisted. Tegmen Y-shaped, weakly sclerotized, almost translucent.

Female. Body more robust than male, apical hollow in ventrite 5 shallow and triangular. Spermatheca (Figs. 28-1C; 28-2G) falcate, 45°-angled bending halfway, slightly acute at apex; duct weakly sclerotized, irregularly coiling 3–5 times. Rectal sclerites (Fig. 28-1G) moderately sclerotized, sclerite slightly narrow, not connected between two rectangular sclerites on ventral side.

Distribution. China (Tibet).

Diagnosis. This species is easily distinguished from all its congeners by the markings of elytra and the clypeus.