Cybister brevis Aubé, 1838

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 : 91-93

Cybister brevis Aubé, 1838

( Figs 12A–E ; 18G ; 22A )

Cybister brevis Aubé, 1838:98 (orig.descr.); KANO (1931): 177 (Taiwan); FALKENSTRÖM (1936): 238 (Sichuan); LI (1992): 36 (Liaoning).

Material examined. CHINA: GUIZHOU: 1 J, Jiangkou County, Shengxisi, 19.vi.1984 ( SYSU); 1 J, west slope of Fanjingshan Mt., Huguosi, 1.viii.2001, H. Pang leg. ( SYSU). HUNAN: 1 J, Longshan County, Tongche, 5.vi.1965, Z. Y. Chen leg. ( SYSU). ZHEJIANG: 2 JJ 1 ♀, Quzhou, Kecheng district, Lankeshan Mt., 28.8781N, 118.9199E, 118 m, 18.iii.2020, Z. Y. Jiang leg. ( SYSU).

Diagnosis. TL 20–25 mm, elongate, oblong-oval ( Fig. 12A ). Head dark green, clypeus orange. Pronotum and elytra dark green to black, apex of elytra with reddish-brown spots. Ventral surface black; abdominal ventrites III–IV with a yellow spot on each side ( Fig. 12B ). Head and pronotum densely covered with coarse punctures, elytra sparsely covered with inconspicuous small granules. 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 reddish-brown, midlegs and hindlegs reddish-brown to black; protarsomeres 1–3 of male broadly expanded into a palette, with four rows of adhesive setae on their ventral side; male with a single metatarsal claw; female with two metatarsal claws, posterior claw small and sinuate. Median lobe of aedeagus ʻCʼ- shaped in lateral view, slightly curved, gradually broader from base to apex, then strongly narrowing at apex ( Fig. 12C ); broad medially in ventral view, apex obtuse-angled ( Fig. 12D ). Parameres moderately broad, strap-like apically ( Fig. 12E ).

Habitat. This species inhabits ponds, abandoned paddy fields and ditches of paddy fields with aquatic plants (MORI

& KITAYAMA 1993); specimens from Lankeshan Mt. (Zhejiang) were found in a natural pond ( Fig. 18G ).

Distribution. China (Guizhou, Hunan, Liaoning, Sichuan, Taiwan, Zhejiang) ( Fig. 22A ), Japan, South Korea (RḖGIMBART 1899, ZIMMERMANN 1920, FENG 1933a, GSCHWENDTNER 1938, ZAITZEV 1972, MORI & KITAYAMA 1993, NILSSON 1995, NILSSON & HÁJEK 2022b). First record from Guizhou, Hunan and Zhejiang.

Figures

Fig. 12. Cybister brevis Aubé, 1838 (J, Lankeshan Mt., Zhejiang).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. 18. Habitats of Cybister in China. A–C – lake, Shanxi (C. chinensis); D–E – lowland marsh, Shenzhen, Guangdong (C. rugosus, C. tripunctatus lateralis and C. sugillatus); F – temporary pond in a valley, Danxiashan Mt., Guangdong (C. tripunctatus lateralis and C. limbatus); G – natural pond, Lankeshan Mt., Zhejiang (C. rugosus and C. brevis); H – terraced fields pools, Lvchun County, Yunnan (C. convexus and C. sugillatus).

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