Cybister ventralis Sharp, 1882

Jiang, Zhuo-Yin, Zhao, Shuang, Mai, Zu-Qi, Jia, Feng-Long & Hendrich, Lars, 2023, Review of the genus Cybister in China, with description of a new species from Guangdong (Coleoptera: Dytiscidae), Acta Entomologica Musei Nationalis Pragae 63 (1), pp. 75-102 : 90-91

Cybister ventralis Sharp, 1882

( Figs 11A–E ; 22A )

Cybister ventralis Sharp, 1882: 742 (orig. descr.); KANO (1931): 177

(Taiwan); FENG (1933a): 329 (Sichuan, Shandong: Qingdao).

Material examined. None from China. INDIA: 1 J 2 ♀♀, Behar, India or., Coll.A. Zimmermann ( ZSMG). SRI LANKA: 1♀, Negombo, 1899, W. Horn, Coll. A. Zimmermann ( ZSMG).

Diagnosis. TL 28–32 mm, broad, oblong-oval ( Fig. 11A ). Head dark green, clypeus yellow. Pronotum dark green to black with lateral yellow margins projecting a little inwards along anterior margin behind eyes; elytra dark green to black, with distinct yellow margin laterally, apex of yellow margin on elytra hooked. Ventral surface yellow with central part of metaventrite and metacoxae black; abdominal ventrites III–V yellowish with a dark brown band anteriorly ( Fig. 11B ). Dorsal surface dimorphic in females: smooth or with isolated short, irregular striae on pronotum and dense longitudinal striae of three-fourths of elytral length from base. Prosternal process lanceolate, with distinct lateral bead, surface flat, apex pointed; lateral parts of metaventrite tongue-shaped, slender, not reaching lateral margins; metacoxal lines distinct, well impressed, nearly parallel medially, divergent anteriorly, along metacoxal lines with a row of punctures. Forelegs and midlegs yellow, tarsi darker; metafemur and metatibia yellow with broad dark brown marking; female with a single metatarsal claw. Median lobe of aedeagus ʻCʼ- shaped in lateral view, moderately curved ( Fig. 11C ); slightly narrow near apex in ventral view, apex furcate, with a notch medially, lateral margins of apex concave ( Fig. 11D ). Parameres more elongate, strap-like apically ( Fig. 11E ).

Distribution. China ( Macao, Sichuan, Shandong, Taiwan) ( Fig. 22A ), Bangladesh, India, Myanmar, Pakistan, Sri Lanka (RḖGIMBART 1899, ZIMMERMANN 1920, KANO 1931, FENG 1933a, VAZIRANI 1969, NILSSON 1995, GHOSH & NILSSON 2012, NILSSON & HÁJEK 2022b).

Figures

Fig. 11. Cybister ventralis Sharp, 1882 (J♀, Pusa, Bihar, India). A – habitus in dorsal view; B – habitus in ventral view; C – median lobe of aedeagus in lateral view; D – median lobe of aedeagus in ventral view; E – paramere. Scale bars: 5.0 mm (A, B), 1.0 mm (C–E).

Fig. 22. Map of distribution of Cybister in China.