Cybister rugosus (W. S. Macleay, 1825 )

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 : 85-89

Cybister rugosus (W. S. Macleay, 1825)

( Figs 9A–E ; 18D–E, G ; 19C ; 21A)

Dytiscus rugosus W. S. Macleay, 1825: 32 (orig. descr.).

Cybister indicus Aubé, 1838: 62 (orig. descr.), synonymy by SHARP (1882: 992).

Cybister rugosus: NILSSON (1995) : 78 (Taiwan).

Material examined. CHINA: CHONGQING: 1 J, Fengdu County, Shiping Village, 610 m, 5.x.1994, J. Chen leg. ( SYSU); 2 JJ, Fengdu County, Shiping Village, 580 m, 6.x.1994, J. Yao leg. ( SYSU). GUANG- DONG: 1J 2♀♀, suburbs of Guangzhou, 6.xi.1956 ( SYSU); 1♀, Nanhai District, Jiujiang Township, 16.xi.1957, D. X. Gu leg. ( SYSU); 69 spec., Guangzhou, 14.xi.1964, T. X. Peng got from market ( SYSU); 1 J, Sanshui District, 18.xi.1964, T. X. Peng leg. ( SYSU); 2 JJ, Nanhai District, Xiqiaoshan Mt., 11.x.1973, S. T. Lu leg. ( SYSU); 1 J, Guangzhou, Sun Yat-sen University, x.1973, S. T. Lu leg. ( SYSU); 1 J, Dinghushan Mt., 28.vi.1978, Z. Y. Wang leg. ( SYSU); 1 J, Guangzhou, Sun Yat-sen University, in front of Huaishitang, 2.x.1999, L. Z. Hua leg. ( SYSU); 1 ♀, Shaoguan, Danxiashan Mt., 30.v.–8.vi.2008, F. L. Jia leg. ( SYSU); 1 J, Fengkai County, He’erkou, light trap, 2.xii.2010, L. J. Yang & Y. L. Yu leg. ( SYSU). HUBEI: 1 ♀, Hwang-mei & vicinity, Hwang-mei Dist., 9.–11.vii.1935, H. W. Djou ( SYSU). HUNAN: 1 J, Tongdao County, 20.viii.1982, Z. H. Huang leg. ( SYSU); 1 J, Hengyang, Zhoujiaao, 28.vi.1986, Q.Zou leg. ( SYSU). JIANGXI: 1♀, main peak of Jinggangshan Mt., 1.ix.2011, L. J. Yang leg. ( SYSU); 1 J, Nanchang ( SYSU); 1 ♀, Shusi, H. Y. Cai leg. ( SYSU). YUNNAN: 1 ♀, Yingjiang County, 820 m, 25.v.1983, L. Z. Hua leg. ( SYSU). ZHEJIANG: 2 ♀♀, Kecheng district, Lankeshan Mt., Quzhou, 28.8781N, 118.9199E, 118 m, 18.iii.2020, Z. Y. Jiang leg. ( SYSU).

Diagnosis. TL 27–33 mm, elongate, oblong-oval ( Fig. 9A ). Head dark green, clypeus yellow. Pronotum and elytra dark green to black, with distinct yellow margins laterally, apex of yellow margin on the elytra hooked. Ventral surface black with lateral part of metaventrite and metacoxae yellow; abdominal ventrites I–V with yellow spot on each side ( Fig. 9B ). Dorsal surface dimorphic: smooth sometimes with inconspicuous small granules in male; in female with isolated short, irregular striae on pronotum and dense longitudinal striae of various length on elytra at its apex. 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 yellow, midlegs and hindlegs yellow to black; protarsomeres 1–3 of male broadly expanded into a palette, with four rows of adhesive setae on their ventral side; both sexes with a single metatarsal claw. Median lobe of aedeagus ʻCʼ- shaped in lateral view, moderately curved ( Fig. 9C ); slightly narrow near apex in ventral view, apex furcate, with a notch medially, lateral margins of apex concave ( Fig. 9D ). Parameres moderately broad, strap-like apically ( Fig. 9E ).

Habitat. This species inhabits ponds, abandoned paddy fields and wetlands with aquatic plants (MORI & KITAYA- MA 1993); specimens from Shenzhen (Guangdong) were found in a lowland marsh ( Figs 18D–E ) and specimens from Lankeshan Mt. (Zhejiang) were found in a natural pond ( Fig. 18G ).

Distribution. China (Chongqing, Guangdong, Hubei, Hunan, Jiangxi, Taiwan, Yunnan, Zhejiang) ( Fig. 21A), Cambodia, Indonesia (Java, Kalimantan), Japan, Laos, Malaysia, Singapore, Thailand, Vietnam (RḖGIMBART 1899, ZIMMERMANN 1920, GSCHWENDTNER 1938, MORI & KITAYAMA 1993, NILSSON 1995, HENDRICH et al. 2004, HENDRICH & BRANCUCCI 2013). First record from Chongqing, Guangdong, Hubei, Hunan, Jiangxi, Yunnan and Zhejiang.

Cybister tripunctatus lateralis ( Fabricius, 1798) ( Figs 10A–E ; 18D–F ; 19D ; 21B)

Dytiscus lateralis Fabricius, 1798: 64 (orig. descr.).

Cybister asiaticus Sharp, 1882:731 (orig. descr.), synonymy by NILSSON (2001: 90).

Cybister gotschii Hochhuth, 1846: 214 (orig. descr.), synonymy by NILSSON (2001: 90).

Cybister similis Régimbart, 1899: 352 (orig. descr.), synonymy by NILSSON (2001: 90).

Cybister tripunctatus orientalis Gschwendtner, 1931: 99 (orig. descr.), synonymy by NILSSON (2001:90); FENG (1932):37 and FENG (1933a): 329 (Sichuan, Hubei:Wuchang, Fujian:Fuzhou and Xiamen, Guangdong, Hainan); BRINCK (1946): 151 (Heilongjiang); ZHAO (1981): 110 (Fujian); ZENG (1989): 91 (Fujian, Guangdong, Hainan, Hubei, Hunan, Jiangsu, Sichuan, Yunnan, Xizang, Zhejiang); LI (1992): 36 (NE China); PU et al. (1992): 484 (Yunnan); MORI & KITAYAMA (1993): 142 (Taiwan).

Cybister szechwanensis Falkenström, 1936: 238 (orig. descr.), synonymy by JIA et al. (2010: 258).

Cybister tripunctatus lateralis: JIA et al.(2010) :258 (NE China, N China, Fujian, Guangdong, Hainan, Hubei, Hunan, Jiangsu, Sichuan, Taiwan, Yunnan, Xizang, Zhejiang).

Material examined. CHINA: CHONGQING: 1 ♀, Jinyunshan Mt., 800

m, 13.vi.1994, Y. W. Zhang leg. ( SYSU). FUJIAN: 1 J, Haitong, NR.,

Foot How, iii.1926, H.T. Chen ( SYSU); 1J, Fuqing, Xitai, 6.–13.x.1932

( SYSU); 1 J, Nan-ping District, Yen-ping, vi.–vii.1933, D. C. Ngu

( SYSU). GUANGDONG: 1 J 2 ♀♀, Ch’eng-hai District, K’ei-luk, Swa-

tow, viii.1932, Y. C. Ng ( SYSU); 1 J, Lingnan University, 10.vi.1948

( SYSU); 3 ♀♀, suburbs of Guangzhou, 6.xi.1956 ( SYSU); 1 J 2 ♀♀,

Guangzhou, Honam Island, 2.–9.xi.1957, D. X. Gu leg. ( SYSU); 6 JJ

6 ♀♀, Nanhai District, Jiujiang Township, 16.xi.1957, D. X. Gu leg.

( SYSU); 1 J 2 ♀♀, Guangzhou, Xinshi, 11.x.1964, C. M. Chen & Z.

W. Huang leg. ( SYSU); 1 J, Guangzhou, Lianhe, 18.x.1964, Z. Y. Chen leg. ( SYSU); 1♀, Guangzhou, Baiyunshan Mt., 2.xi.1964, J. C. Bao leg.

( SYSU); 126 spec., Guangzhou, 14.xi.1964, T. X. Peng got from market

( SYSU); 1♀, Guangzhou, 18.xi.1964, T. X. Peng leg.( SYSU); 1J, Nanhai District, Shijing Village, 10.x.1973, S. T. Lu leg. ( SYSU); 84 spec.,

Nanhai District, Xiqiaoshan Mt., 10.–11.x.1973, S. T. Lu leg. ( SYSU); 1

J 2 ♀♀, suburbs of Guangzhou, Renhe Township, 26.–27.x.1973, S. T.

Lu leg. ( SYSU); 1 ♀, Nanhai District, 2.xi.1973, S. T. Lu leg. ( SYSU); 1

J, Shunde District, Xingtan Township, 2.xi.1973, S. T. Lu leg. ( SYSU);

1 ♀, Guangzhou, Baiyunshan Mt., 6.xi.1973, S. T. Lu leg. ( SYSU); 1 ♀, Ruyuan County, Luoyang Commune, 26.v.1974, C. Liao leg. ( SYSU); 1 J, Guangzhou, Kangle, 28.iv.1989, F. L. Jia leg. ( SYSU); 1 J 1 ♀, Shenzhen, Noi Ling Ding Island, 20.x.1998, H. D. Chen leg. ( SYSU); 1 J 1 ♀, Xinhui District, viii.2001, X. L. Tong leg. ( SYSU); 4 JJ 11 ♀♀, Gaoming District, Yangmei Township, 20.–27.iv.2006, F. L. Jia et al. leg. ( SYSU); 1 J, Lian County, Dadongshan Mt., 3.–9.vii.2008, W. C. Xie leg.( SYSU); 1♀, Lianjiang City, 26. ix.2008 ( SYSU); 1J, Fengkai County, Heishiding, 5.x.2011, Y. Li leg. ( SYSU). GUANGXI: 2 JJ, Rong County, 10.x.1962, D. X. Gu leg. ( SYSU); 4 JJ 2 ♀♀, Nanning, 19.vi.1977, Z. H. Huang leg. ( SYSU). HAINAN: 1 J, Jianfengling Mt., 18.xii.1963, T. X. Peng leg. ( SYSU); 3 JJ 1♀, Sanya, 24.xii.1963, T. X. Peng leg. ( SYSU); 1 J, Dongfang-Huangliu, 25.xii.1963, T. X. Peng leg. ( SYSU); 2 JJ, Tongshi, 27.xii.1963, T. X. Peng leg. ( SYSU); 1 J, Lingshui County, Diaoluoshan Mt., Xiaomei Village, 29.xii.1963, L. F. Huang leg. ( SYSU); 1 ♀, Qionghai, Shangyong Village, light trap, 17.vii.1984, C. L. Wang leg. ( SYSU). HUBEI: 1 J, Zigui County, Maoping Township, 80 m, 28.iv.1994, W. Z. Li leg. ( SYSU). HUNAN: 2 JJ, Tongdao County, 20.viii.1982, Z. H. Huang leg. ( SYSU); 1 ♀, Hengyang, Zhoujiaao, 2.vii.1986, Q. Zou leg. ( SYSU). JIANGXI: 1 ♀, Nanchang, iii.1963, X. W. Chen leg. ( SYSU); 1 ♀, Nanchang ( SYSU). SHANGHAI: 1J, Shanghai, 16.ii.1926, W.E.Hoffmann ( SYSU). YUNNAN: 1 ♀, Xishuangbanna, Menglun Township, light trap, 580 m, 13.ix.1993, H. L. Xu leg. ( SYSU); 1 ♀, Xishuangbanna Tropical Botanical Garden, 650 m, 9.viii.2003,Y.Zhang leg. ( SYSU). XIZANG: 1♀, Gyirong County, Gyirong Commune, 26.vii.1984, Z. X. Yan leg. ( SYSU); 5 JJ 10 ♀♀, Linzhi, Mêdog County, Beibeng Township, Didong Village, 840 m, 16.viii.2006, M. Bai leg. ( SYSU); 3 JJ 1 ♀, Linzhi, Mêdog County, Beibeng Township, 887 m, 17.viii.2006, M. Bai leg. ( SYSU); 3 JJ 2 ♀♀, Linzhi, Mêdog County, Yarang Township, Didong Village, 760 m, 19.viii.2006, M.Bai leg. ( SYSU); 20 spec., Linzhi, Mêdog County, 1084 m, 21.viii.2006, M. Bai leg. ( SYSU); 20 spec., Linzhi, Mêdog County, 1084 m, 23.viii.2006, M. Bai leg. ( SYSU); 1 J, Linzhi, Mêdog County 80K, 2110 m, 24.viii.2006, M. Bai leg. ( SYSU).

Diagnosis. TL 24–28 mm, elongate, oblong-oval ( Fig. 10A ). Head dark green, clypeus yellow. Pronotum and elytra dark green to black, with distinct yellow margins laterally, apex of yellow margin on the elytra slightly hooked. Ventral surface black, sometimes with lateral part of metaventrite and metacoxae yellow; abdominal ventrites III–V with a yellow spot on each side ( Fig. 10B ). Dorsal surface smooth in both sexes. 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; metatarsal claws single in both sexes. Median lobe of aedeagus ʻCʼ- shaped in lateral view, moderately curved ( Fig. 10C ); slightly narrow near apex in ventral view, apex furcate, with a deep acute-angled notch medially, lateral margins of apex convex ( Fig. 10D ). Parameres moderately broad, tapering apically ( Fig. 10E ). Habitat. The most common species of the genus in Southeast Asia. An eurytopic species which is widespread in artificial habitats such as irrigation channels, flooded paddy fields, open swamps, fish and ornamental ponds and larger ditches, even in urban and suburban areas ( MORI & KITAYAMA 1993, HENDRICH et al. 2004). Specimens from Shenzhen (Guangdong) were found in a lowland marsh( Figs 18D–E ) and specimens from Danxiashan Mt. (Guangdong) were found in a temporary pond in a valley ( Fig. 18F ).

Distribution. China (Chongqing, Fujian, Guangdong, Guangxi, Hainan, Hebei, Heilongjiang, Hubei, Hunan, Jiangsu, Jiangxi, Macao, Shanghai, Sichuan, Taiwan, Yunnan, Xizang, Zhejiang) ( Fig. 21B), Afghanistan, United Arab Emirates, Azerbaijan, Bhutan, Cyprus, India, Iran, Iraq, Japan, Kyrgyzstan, Laos, Mongolia, Nepal, Oman, Pakistan, Russia, Singapore, Syria, Thailand, Tajikistan,

Turkmenistan, Turkey, Uzbekistan (RḖGIMBART 1899; ZIMMERMANN 1920; FENG 1932, 1933a,b; GSCHWENDTNER 1938; VAZIRANI 1969; ZAITZEV 1972; ZENG 1989; MORI & KITAYAMA 1993; HENDRICH et al. 2004; GHOSH & NILSSON 2012; HENDRICH & BRANCUCCI 2013; NILSSON & HÁJEK 2022b). First record from Chongqing, Guangxi, Jiangxi and Shanghai.

Figures

Fig. 9. Cybister rugosus (W. S. Macleay, 1825) (J, Fengkai County, Guangdong). 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. 19. Live specimens of Chinese Cybister. A – C. chinensis Motschulsky, 1854 (mating couple); B – C. lateralimarginalis torquatus (Fischer von Waldheim, 1829); C – C. rugosus (W. S. Macleay, 1825); D – C. tripunctatus lateralis (Fabricius, 1798); E – C. convexus Sharp, 1882; F – C. sugillatus Erichson, 1834.

Fig. 10. Cybister tripunctatus lateralis (Fabricius, 1798) (J, Guangzhou, Guangdong).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).