Adiscus bicoloriceps (Pic, 1932)

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 : 20-23

Adiscus bicoloriceps (Pic, 1932)

(Figs 7-1; 7-2)

Dioryctus bicoloriceps Pic, 1932a: 208 (type locality: China; type deposited: MNHN).

Adiscus bicoloriceps: Gressitt & Kimoto, 1961: 116 ; Schöller et al., 2010: 607 (catalogue).

= Dioryctus bicoloriceps var. interruptus Pic, 1954: 56 (type locality: Kuatun)

= Adiscus bicoloriceps var. interruptus: Gressitt & Kimoto, 1961: 116 (synonym of A. bicoloriceps ).

Material examined. CHINA: Fujian province: 1 female, Jianyang, Huangkeng , 25. III. 1960, coll. Shengqiao Jiang ( IZ-CAS) ; 2 females, Jianyang, Huangkeng , 25. III. 1960, coll. Fuji Pu ; 1 female, Jianyang, Huangkeng , 26. III. 1960, coll. Chenglin Ma ( IZ-CAS) ; 1 female, Jianyang, Huangkeng , 26. III. 1960, coll. Yong Zuo ( IZ-CAS) ; 2 females, Jianyang, Huangkeng , 27. III. 1960, coll. Fuji Pu ( IZ-CAS) ; 2 females, Jianyang, Huangkeng , 27. III. 1960, coll. Yiran Zhang ( IZ-CAS) ; 1 female, Jianyang, Huangkeng , 27. III. 1960, coll. Shengqiao Jiang ( IZ-CAS) ; 1 female, Jianyang, Huangkeng , 29. III. 1960, coll. Yong Zuo ( IZ-CAS) ; 1 female, Jianyang, Huangkeng , 25. III. 1960, coll. Shengqiao Jiang ( IZ-CAS) ; 1 female, Jianyang, Huangkeng , 2. IV. 1960, coll. Fuji Pu ( IZ-CAS) ; 3 males, 4 females, Jianyang, Huangkeng , 29. IV. 1960, coll. Fuji Pu ; 1 female, Jianyang, Huangkeng, Guilin , 4. IV. 1960, coll. Yong Zuo ( IZ-CAS) ; 1 female, Jianyang, Huangkeng, Guilin , 7. IV. 1960, coll. Shengqiao Jiang ( IZ-CAS) ; 1 female, Jianyang, Huangkeng, Guilin , 10. IV. 1960, coll. Fuji Pu ( IZ-CAS) ; 1 female, Jianyang, Huangkeng, Guilin , 17. IV. 1960, coll. Fuji Pu ( IZ-CAS) ; 1 female, Chong’an, Xing Village, Sangang 17. IV. 1960, coll. Yiran Zhang ( IZ-CAS) .

Redescription. Measurements. Males. BL = 3.68–4.02 mm, BW = 2.52–2.78 mm, HL = 1.48 mm, HW = 1.36 mm, PL = 1.49 mm, PW = 2.45 mm, PA = 100°, EL = 2.76 mm, EA = 130°, AL = 1.24 mm, AW = 0.42 mm.

Females. BL = 4.01–5.12 mm, BW = 2.54–2.95 mm, HL = 1.60 mm, HW = 1.48 mm, PL = 1.61 mm, PW = 2.65 mm, PA = 100°, EL = 2.98 mm, EA = 130°, SL = 0.59 mm.

Body (Figs. 7-1A; 7-2A) ovate, dorsum convex. Head basal region black, apical region yellowish brown. Labrum yellowish brown, mandibles yellowish brown, apex black; maxillary palpus and last segment of labial palpus black. Antennomeres 1–4 yellowish brown, 5 darkish brown, 6–11 black. Pronotum yellowish brown, basal margin black. Elytra black, disc either with a round and medium-sized yellowish brown mark, covering about 1/3 area of elytra and extending from the interspace of 1 st and 2 nd puncture rows to 8 th, or elytra largely yellowish brown with black basal margin and subapical spot. Legs largely yellowish brown, lateral surface of tibiae black, tarsi slightly brown. Venter mostly yellowish brown, prosternum and mesoventrite black.

Head with dense and coarse punctures, densely strigose on frons. Eyes reniform; superior eye-lobes separated by slightly greater distance than antennal insertions. Clypeus arched and slightly emarginated. Antennae long, reaching apex of basal 1/3 of elytra; scape broad and long, pedicel shortest, antennomeres 3 and 4 slender, 3 slightly shorter than 4, 5 broader, as long as 4 while longer than 3, 6–11 somewhat broadened and each segment broader than long, but not flattened.

Pronotum (Figs. 7-1A; 7-2A) broadly smooth and glabrous, base much broader than apex, with basal width about 2.5 times of pronotal length. Anterior margin nearly straight; posterior margin undulated slightly, and its middle portion produced into an obtuse angle of about 100°. Disc evenly convex, impunctate.

Elytra (Figs. 7-1A; 7-2A) almost as broad as long, humeri somewhat prominent and glabrous. Disc evenly and moderately punctate, with 11 regular striae, intervals scatted with minute punctures. Epipleural lobe (Fig. 7-2B) large, lateral margins distinctly expanded ventrally with rounded lobe at basal 1/4 of elytron, with both lobe sides forming angle of 130°, epipleura obliquely placed and visible in lateral view.

Venter clothed with dense and short pubescence. Prosternum (Fig. 7-2C) trapezoidal, with coarse and dense punctures, posterior margins slightly emarginated, hind angles not produced, lateral ridges elevated, straight in lateral view. Mesoventrite with dense coarse punctures, about twice as wide as long. Pygidium with dense and coarse punctures. Front and middle legs swollen, femur robust, apex of tibiae thick, tarsi inflated.

Aedeagus. (Figs. 7-1D–F; 7-2D–F) Median lobe elongate, about 3 times as long as wide, parallel-sided, apex of median lobe slightly narrower than middle, strongly arcuate at apex; with several setae on each side of apex, impunctate on ventral side. Median orifice with median sclerite bending inwards beyond surface at one-ninth of median lobe. Inner sac almost round, bilobed and narrowed from apex, truncate at bottom. Tegmen Y-shaped, almost bifurcate at basal 1/3, weakly sclerotized, nearly translucent.

Female. Body more robust than male, apical hollow in ventrite 5 shallow. Spermatheca (Figs. 7-1C; 7-2G) falcate, swollen at base, 45°-angled bending halfway, acute at the apex; duct base thickened strongly, coiled, then becoming thinner, weakly sclerotized, and irregularly coiled about 2–3 times. Rectal sclerites (Fig. 7-1G) strongly sclerotized, two sclerites slender, rectangular, almost connected in ventral view.

Distribution. China (Fujian, Taiwan).