taxonID	type	description	language	source
03F687FE434CBC620CD7FDDCFA1472A8.taxon	description	(Figs. 1 – 71)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434CBC620CD7FDDCFA1472A8.taxon	discussion	For complete synonymy, see Hansen (1999).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434CBC620CD7FDDCFA1472A8.taxon	diagnosis	Diagnosis. Body oblong oval to broadly oval, moderately to strongly convex, more or less uniformly brown to black; antenna with 9 antennomeres in Asian species, antennal bases concealed by lateral parts of clypeus, club (antennomeres 7 – 9) loosely segmented or compact; labrum completely concealed by clypeus or partially exposed in front of clypeus in Chinese and Japanese species; frontoclypeal suture distinct; maxillary palps with 4 palpomeres, stout; labial palps with 3 palpomeres, rather stout; gula forming a transverse triangle posteriorly, narrow and parallelsided anteriorly; prosternum more or less tectiform medially, often with a distinct tooth anteromedially; hypomeron pubescent except on marginal portion, without defined antennal grooves; metaventrite with pubescence except on raised median portion; metaventral process strongly projecting anteriorly between mesocoxae, abutting mesoventral elevation; elytron with at least 9 rows of serial punctures or striae, the outer serial punctures usually larger and deeper than the inner serial punctures; sides of elytron more or less explanate at least in posterior half; elytral epipleuron wide and reaching elytron end; first abdominal ventrite with complete or almost complete carina medially.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434CBC620CD7FDDCFA1472A8.taxon	biology_ecology	Biology. All species of Dactylosternum for which biology is known are terrestrial. They usually occur in various types of decaying plant material, including that under bark of freshly cut trees (Bloom 2014) and in tropical forest leaf litter (Fikáček 2010, Fikáček et al. 2020). In tropical areas, Dactylosternum abdominale (Fabricius, 1792) was found in banana trees (Figs. 65, 67) and its larvae are predators of the banana weevil (Koppenhöfer 1995); in temperate areas the same species is found in domestic waste or farmyard manure (Lõkkös 2009). Dactylosternum cacti (LeConte, 1855) in inhabiting rotting cactus tissues (Archangelsky 1994, Arriaga-Varela et al. 2019). Many Chinese species were collected in the decaying pseudostem of banana plants and in rotten wood (Figs. 67 – 69). Dactylosternum nanlingensis Mai et Jia, sp. nov. was collected from fungal hyphae on fallen wood (Figs. 64, 66), and D. songxiaobini Mai et Jia, sp. nov. was collected from a rotten wood with termites.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434CBC620CD7FDDCFA1472A8.taxon	synonymic_list	Dactylosternum abdominale (Fabricius, 1792) Dactylosternum corbetti Balfour-Browne, 1942 Dactylosternum frater Mai et Jia, sp. nov. Dactylosternum hydrophiloides (MacLeay, 1825) Dactylosternum latum (Sharp, 1873) Dactylosternum nanlingensis Mai et Jia, sp. nov. Dactylosternum pseudolatum Mai et Jia, sp. nov. Dactylosternum pui Jia, 2002 Dactylosternum salvazai Orchymont, 1925 Dactylosternum songxiaobini Mai et Jia, sp. nov. A list of Japanese Dactylosternum Wollaston, 1854 Dactylosternum abdominale (Fabricius, 1792)? Dactylosternum latum (Sharp, 1873) (doubtful)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434DBC640CD7F9CAFECC748D.taxon	description	(Figs. 1, 20, 40, 47, 67)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434DBC640CD7F9CAFECC748D.taxon	materials_examined	Type material: not examined. Material examined. CHINA: Guangdong: 24 spec. (SYSU), Shipai Cattle Camp, 25. VII. 1985, Wu leg.; 24 spec. (SYSU), Henan Cattle Camp, 10 – 25. X. 1985, Wu leg.; 5 spec. (SYSU), Guangzhou, Yingzhou Ecological Orchard, in the rotten banana root, 29. VIII. 2010, Jia leg.; 5 spec. (SYSU), Foshan Prefecture, Sanshui District, in the rotten banana tree, 23. VIII. 2012, Jia & Song leg.; 6 spec. (SYSU), Guangzhou, Haizhu District, Wanmu Orchard, 27. VIII. 2012, Song leg.; 14 spec. (SYSU), Fengkai County, Heishiding, 23 ° 31 ′ N 111 ° 52 ′ E, in the rotten bamboo, 21. I. 2014, Lin leg.; 7 spec. (SYSU), Shenzhen, Dapeng District, Shenshuitian, 22 ° 38 ′ 36 ″ N 114 ° 26 ′ 16 ″ E, 40 m, in the rotten wood, 23. VII. 2019, Liang, Yang, Jiang & Ji leg.; Guangxi: 1 spec. (SYSU), Baise Prefecture, Pingguo County, Matou Town, in the farmyard manure, 23.350213 ° N, 107.559134 ° E, 103 m, 28. IV. 2021, Bao-ping Huang & Zu-qi Mai leg.; Macao: 3 spec. (SYSU), Dangzai Mangrove Reserves, 22 ° 8 ′ 24 ″ N 113 ° 33 ′ 11 ″ E, 12 m, in the rotten banana tree, 16. I. 2021, Jia & Mai leg.; Nei Mongol: 1 female (SYSU), Yitulihe Town, 13 – 15. VIII. 2008, Jia leg. JAPAN: Kagoshima Pref.: 1 spec. (SSC), Amami Is, Tokunoshima I., 26 – 29. VI. 2011, S. Sakurai leg.; Okinawa Pref.: 2 spec. (SSC, KMNH), Miyako-jima I., 26 – 28. ii. 2005, S. Sakurai leg.; 1 male (KMNH), Yonaguni-jima I., Sonai, 25. xii. 2005; Y. Minoshima leg.; 1 male, 1 spec. (KMNH), Yonaguni-jima I., Sonai, 24 ° 27.9 ′ N, 123 ° 00.2 ′ E, 29. xii. 2005, at light, Y. Minoshima leg. Additional material examined. VIETNAM: 1 spec. (FEFU), Hanoi Hotel Kim-lien, 1 – 2. V. 1966, Exp. Gy. Topál, Nr. 245, from decaying banana tree, Dactylosternum abdominale (Fabricius), Det. M. Sato, 1980; 1 spec. (FEFU), Hanoi Hotel Kim-lien, 1 – 2. V. 1966, Exp. Gy. Topál, Nr. 244, singled from carcass of rat, Dactylosternum abdominale (Fabricius), Det. M. Sato, 1980.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434DBC640CD7F9CAFECC748D.taxon	diagnosis	Diagnosis. Length 4.4 – 5.0 mm, maximum width 2.5 – 2.8 mm. Body oblong oval, anterior half of elytra nearly parallel-sided (Fig. 1); elytra weakly convex. Dorsal black to dark brown. Anterior margin of clypeus without marginal rim. Clypeus, posterior margin of vertex and lateral portion of pronotum with distinct mesh-like microsculpture between punctures (Fig. 47). Antenna yellow-brown, with club black to yellow-brown, club compact (Fig. 40). Elytron with sutural stria and 10 rows of serial punctures, all nearly reaching elytral base. Aedeagus (Fig. 20) ca. 1 mm long. Phallobase ca. 0.6 × as long as parameres. Parameres slender, mostly membranous in apical half, truncate and widened apically; the widening is often not distinct due to modification of membranous apex during preparation or due to an intraspecific variation. Median lobe shorter than parameres, ca. 0.7 × as long as parameres, moderately stout, elongate, triangular, tapering towards apex; apex of median lobe abruptly tapered with rounded apex. Gonopore situated subapically. For detailed description see Smetana (1978) and Hansen (1991).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434DBC640CD7F9CAFECC748D.taxon	biology_ecology	Biology. (Figs. 65, 67) Found in various types of decaying organic matter, such as rotting plant tissues, domestic waste or farmyard manure, in China often associated with decaying trunks of banana plants and the farmyard manure. Adult individuals are attracted by light.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434DBC640CD7F9CAFECC748D.taxon	distribution	Distribution. China (Nei Mongol, Guangdong, Guangxi, Macao); Japan (Honshu, Kyushu, Nansei-shotô Islands, Ogasawara Islands (e. g., Nakane 1970; Hirano 1985; Satô 1985; Entomological Laboratory & Japan Wildlife Research Center 1989). New for Nei Mongol, China. Outside China and Japan recorded from the following regions: Afrotropical: Benin, Cape Verde Is., Comoros, Guinea, Ivory Coast, Madagascar, Mascarene Is., Nigeria, Senegal, Seychelles, South Africa, Togo, Yemen, Zaire. Palearctic: Algeria, Azores, Canary Is., Croatia, Cyprus, Egypt, France, Germany, Greece, Hungary (Lõkkös 2009), Italy, Japan, Madeira, Spain, Syria, Tunisia. Oriental: Andaman Is., Christmas Is., India, Indonesia (Java, Sumatra), Malaysia (Peninsula), Philippines, Singapore, Sri Lanka, Australian: Australia, Fiji, New Caledonia, New Guinea, New Zealand, Gambier Is., Hawaiian Is., Marquesas Is., Samoa, Society Is., Neotropical: Argentina, Brazil, Cuba, Jamaica, Lesser Antilles, Mexico, Nearctic: U. S. A. (Hansen 1999).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434BBC670CD7FC39FE7A7201.taxon	description	(Figs. 2, 21, 46, 50, 68)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434BBC670CD7FC39FE7A7201.taxon	materials_examined	Type material: not examined. Material examined. CHINA: Guangdong: 1 male (SYSU), Shenzhen, Dapeng District, Shenshuitian, 22 ° 38 ′ 36 ″ N 114 ° 26 ′ 16 ″ E, 40 m, in the rotten wood, 23. VII. 2019, Liang, Yang, Jiang & Ji leg.; 4 spec. (SYSU), Shenzhen, Dapeng District, Jingui Village, Xintang, 22 ° 39 ′ 35 ″ N 114 ° 23 ′ 10 ″ E, 62 m, 15. V. 2019, Xie & Xiang leg.; 17 spec. (SYSU), Taishan Prefecture, Shangchuan Island, Hening Village, 21 ° 43 ′ 59 ″ N 112 ° 46 ′ 35 ″ E, 0 m, 18. I. 2019, Jia & Liang leg. Hong Kong: 1 male (IZCAS), Tai Po District, Sha Lo Tung 187 m, 22.47578 ° N, 114.18192 ° E, 14. iv. 2013, Lin Mei-ying leg. Macao: 12 spec. (SYSU), Dangzai Mangrove Reserves, 22 ° 8 ′ 24 ″ N 113 ° 33 ′ 11 ″ E, 12 m, in the rotten banana tree, 16. I. 2021, Jia & Mai leg.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434BBC670CD7FC39FE7A7201.taxon	diagnosis	Diagnosis. Length 2.9 – 3.8 mm. Body elongate oval, anterior half of elytra nearly parallel-sided (Fig. 2), moderately convex. Dorsal black. Anterior margin of clypeus without marginal rim. Vertex, pronotum and elytron with microsculpture consisting of punctures connected to two short diverging lines forming a flying-bird-like impression, those impressions connected to others in a loose reticulation (Fig. 46). Antenna yellow-brown, club compact. Elytron with 10 distinct rows of serial punctures, all nearly reaching elytral base. Aedeagus (Fig. 21): phallobase rather shorter than parameres; parameres slender and straight; outer margin of median lobe nearly parallel-sided, truncate and slightly concave apically, gonopore situated apically.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434BBC670CD7FC39FE7A7201.taxon	description	Redescription. Total length 2.9 – 3.8 mm; maximum width 1.7 – 2.2 mm; body oblong oval, moderately convex. Coloration. Dorsal black, with lateral margin of elytron slightly paler (Fig. 2). Ventral black. Legs and mouthparts reddish brown. Maxillary palps and antenna yellow brown. Head. Clypeus weakly convex, surface with microsculpture consisting of two short diverging lines connected to each ground pucture, forming a flying-bird-like impression, those impressions connected to others in a loose reticulation. Anterior margin of clypeus without marginal rim. Frons with punctures sparser than those on clypeus. Eyes small, nearly semicircular in dorsal view, separated by ca. 6 × as width as one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with basistipes bearing sparse long setae. Mentum transverse, ca. 1.25 × as wide as long, widest between anterolateral corners, slightly narrowing posteriorly, bearing sparse setae, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum yellow-brown, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longer than other ones. Antennal scapus longest, rather thick, ca. 2 × as long as antennomeres 2 – 6 combined, antennomere 3 thin and almost as long as pedicellus, antennomeres 4 and 5 slightly widening distally, cupula (antennomere 6) short and wide, without any seta, club densely pubescent, with few long setae, compact, ca. 1.6 × as long as wide. Prothorax. Pronotum moderately convex, widest basally, arcuately narrowing anteriorly, anterolateral angles obtusely rounded, posterolateral angles with blunt corners, anterior and lateral margins with narrow marginal bead, surface with punctures similar to those on vertex (Fig. 46). Prosternum weakly tectiform medially, with median carina and a distinct tooth anteromedially. Meso- and metathorax. Scutellum slightly longer than wide, apex rounded, in shape of isosceles triangle, with punctures similar to those on pronotum. Elytron moderately convex, elytral margin slightly explanate in posterior half, sutural stria deeply impressed in posterior half; each elytron with 10 longitudinal serial punctures, all nearly reaching elytral base, the three inner series deeply impressed in posterior half; elytral intervals with flying-bird-like fine punctures sparser than those on pronotum between series (Fig. 50). Epipleuron very wide and strongly oblique, ending at elytral apex, pubescent. Mesoventrite fused to mesepisterna, strongly elevated posteromedially to form an arrowhead-shaped process. Legs. Reddish to yellowish brown, rather short, femora and tibiae flattened. Procoxae globular, pubescent; profemora without pubescence ventrally; protibiae cylindrical, with strong apical spurs and a sparse series of lateral stout spines; protarsomeres pubescent ventrally. Mesocoxae pubescent, separated by metaventral process. Metacoxae pubescent, contiguous medially. Ventral surface of meso- and metafemora without pubescence, with sparse punctures and microsculptures; meso- and metatibiae flattened, with short spines along lateral and mesal faces, and two apical spurs; meso- and metatarsomeres with sparse pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex, with complete marginal bead. Posterior margin of ventrite 5 rounded, with a stria in front of the marginal bead. Male genitalia (Fig. 21). Aedeagus about 0.7 mm long, ca. 2.1 × as long as wide. Phallobase ca. 0.3 × as long as parameres. Parameres straight, gradually narrowing towards apex. Median lobe a little shorter than parameres, ca. 0.7 × as long as parameres, widest basally, outer margin nearly parallel-sided, truncate and slightly concave apically, gonopore situated at apex.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434BBC670CD7FC39FE7A7201.taxon	biology_ecology	Biology (Figs. 65, 68). Living in rotting plant tissues, like rotten wood and rotten banana stems.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE434BBC670CD7FC39FE7A7201.taxon	distribution	Distribution. China (Guangdong, Hong Kong, Macao, Taiwan). Outside of China known from Malaysia and the Philippines (Hansen 1999).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4348BC680CD7FAA0FE0974C5.taxon	description	(Figs. 6, 18, 24, 51, 69)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4348BC680CD7FAA0FE0974C5.taxon	materials_examined	Type material: not examined. Material examined. CHINA: Guangdong: 6 spec. (SYSU), Fengkai County, Heishiding Natural Reserve, decaying pseudostem of banana, 5. VII. 2014, Jia & Song leg.; 1 spec. (SYSU), Fengkai County, Heerkou, decaying bamboo, 15. VIII. 2010, Jia leg.; 12 spec. (SYSU), Guangzhou, Guanzhou Island, pseudostem of banana, 26. VIII. 2012, Song leg.; 4 spec. (SYSU), Guangzhou, Haizhu District, 12. VIII. 2012, Song leg.; 4 spec. (SYSU), Shaoguan Prefecture, Ruyuan County, Danxiashan, Jinshiyan, 22. IV. 2012, Jia & Liao leg.; 1 spec. (SYSU), Heshan Prefecture, 27. VIII. 2002, Liu leg.; 1 spec. (SYSU), Heshan Prefecture, 22 – 24. IV. 2002, Wen leg.; 1 spec. (SYSU), Guangzhou, Sun Yet-sen University, 20. VII. 1997, Jia leg.; 1 spec. (SYSU), Guangzhou, 27. IX. 1993, Liang leg.; 5 spec. (SYSU), Shipai, VII. 1952, Chen leg. 1 spec. (SYSU), Guangzhou, IX. 1964, Li leg.; 1 spec. (SYSU), Shenzhen, Futian District, Meilinyicun, 13. ii. 2017, Huang & Mai leg.; Guangxi: 3 spec. (SYSU), Rongshui County, banana tree, 17. iii. 1959, Wu leg.; 6 spec. (SYSU), Wuzhou, banana tree, 15. iii. 1959, Guangx Team leg.; 3 spec. (SYSU), Longlin County, Jinzhongshan, VIII. 2014, Zhou leg.; 1 spec. (SYSU), Shiwandashan Forest Park, 267 m, light trap, 9. VII. 2011, Song leg.; 1 spec. (IZCAS), Napo, Nonghua, 1000 m, 14. iv. 1998, Li Wen-zhu leg.; Guizhou: 1 spec. (SYSU), Kuankuoshui, 746 m, light trap, 9. VII. 2010, Liu leg.; Hainan: 1 spec. (SYSU), Jianfengling, 9 – 10. V. 2011, Zhao leg.; 1 spec. (SYSU), Jianfengling, light trap, 9. V. 2011, Zhao leg.; 2 spec. (SYSU), Baishabanxi Natural Preservation Zone, 2 – 3. IX. 2013, Xie leg.; 2 spec. (SYSU), Lingmushan, Lingmu Temple, 5 – 6. V. 2011, Zhao leg.; 1 spec. (SYSU), Jianfengling, Tianchi, light trap, 26. VII. 1983, He leg.; 1 spec. (SYSU), Jianfengling, Tianchi, light trap, 17. V. 1985, Long leg.; Hong Kong: 1 spec. (SYSU), Hong Kong Island, VIII. 1933, W. E. Hoffmann leg.; Yunnan: 1 male, 1 female (SYSU), Mengla County, Menglun Reservoir, 620 m, 16. V. 2018, Qiu & Xu leg.; 9 spec. (SYSU), Mengla County, Nazhuo Village, pseudostem of banana, 700 m, 4. X. 2010, Zhou leg.; Mengla County, 850 m, 3. V. 1957, Wang leg.; 7 spec. (SYSU), Xishuangbanna, Nabanhe National Natural Reserve, Naban Village, 12. I. 2004, Li & Tang leg.; 13 spec. (SYSU), Xishuangbanna, Nabanhe National Natural Reserve, Mandian, 11. I. 2004, Li & Tang leg.; 3 spec. (SYSU), Xishuangbanna, Nabanhe National Natural Reserve, Manfei, 9. I. 2004, Li & Tang leg.; 2 males, 2 females (SYSU), Xishuangbanna Botanical Garden, 5. VII. 2003, Hu & Tang leg.; 16 spec. (SYSU), Jiangdong County, Taizhong Town, 24 ° 30 ′ N 100 ° 56 ′ E, 1395 m, 15. IV. 2015, Lin & Tang leg.; 2 spec. (SYSU) Jiangdong County, Taizhong Town, 25 ° 10 ′ N 98 ° 16 ′ E, 1516 m, 18. IV. 2015, Lin & Tang leg.; 6 spec. (SYSU), Yuanjiang County, 500 m, 12. V. 1957, Liang leg.; 3 spec. (SYSU), Xishuangbanna, Jinghong Prefecture, Damenglong Town, 600 m, 29. IV. 1957, Liu leg.; Xizang: 3 spec. (SYSU), Linzhi Prefecture, Motuo County, Yarang, 760 m, 19. VIII. 2006, Bai leg.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4348BC680CD7FAA0FE0974C5.taxon	diagnosis	Diagnosis. Length 5.7 – 8.1 mm. Body elongate oval, anterior half of elytra nearly parallel-sided (Fig. 6), weakly convex. Dorsal black, surface with fine punctures. Anterior margin of clypeus with distinct marginal rim (Fig. 18). Antenna yellow-brown, club compact. Elytron with sutural stria and 10 distinct rows of serial punctures, interstices of ground punctures with dense micropunctures, especially in posterior half (Fig. 51). Aedeagus (Fig. 24): Phallobase almost as long as parameres. Median lobe very short and wide, reaching only to the middle of parameres, gonopore situated subapically.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4348BC680CD7FAA0FE0974C5.taxon	description	Redescription. Total length 5.7 – 8.1 mm; maximum width 3.5 – 4.0 mm; body elongate oval, weakly convex. Coloration. Dorsal black, with lateral margin of elytron slightly paler (Fig. 6). Ventral black. Legs and mouthparts reddish brown. Maxillary palps and antenna yellowish brown. Head. Clypeus weakly convex, surface with dense punctures, anterior portion with denser punctures. Interstices smooth, without microsculpture. Anterior margin of clypeus with distinct marginal rim (Fig. 18). Frons with punctures similar with those on clypeus. Eyes of moderate size, nearly semicircular in dorsal view, separated by ca. 5 × the width of one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with basistipes glabrous. Mentum transverse, glabrous, widest between anterolateral corners, slightly narrowing posteriorly, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum reddish brown, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longer than other ones. Antennal scapus longest, rather thick, ca. 7 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, antennomeres 4 and 5 almost equal in length, slightly widening distally, without any seta, club densely pubescent, with few long setae, compact, ca. 2.5 × as long as wide. Prothorax. Pronotum moderately convex, widest basally, arcuately narrowed in front, anterolateral angles obtusely rounded, posterolateral angles almost rectangular, posterior margin slightly arcuate, anterior and lateral margins with narrow marginal bead, pronotum with punctation similar to those on vertex. Prosternum moderately tectiform medially, with median carina and a distinct tooth anteromedially. Meso- and metathorax. Scutellum distinctly longer than wide, apex rounded, in shape of isosceles triangle, with punctuation similar to those on pronotum. Elytron moderately convex, sutural stria deeply impressed in posterior half; each elytron with 10 longitudinal serial punctures, punctures impressed mesally, becoming slightly sulcate posteriorly and laterally, with shallow fine punctures between serial punctures; series 3 + 4 and 6 + 7 linked together subposteriorly, other serial punctures reaching end of elytron; lateral four series with punctures larger and deeper than in inner six series; interstices of ground punctures with dense micropunctures in posterior half of elytron, especially in females (Fig. 51). Legs. Reddish brown, rather short, profemora without pubescence ventrally; protarsomeres pubescent ventrally. Ventral surface of meso- and metafemora without pubescence, with sparse punctures and microsculptures; meso- and metatarsomeres with sparse pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex, with complete marginal bead. Posterior margin of ventrite 5 rounded, with a stria in front of the marginal bead. Male genitalia (Fig. 24). Aedeagus about 1.7 mm long, ca. 4 × as long as wide. Phallobase well developed, almost as long as parameres. Parameres widest in the middle, gradually narrowing towards apex. Median lobe almost as wide as phallobase, apex rounded, reaching only to the middle of parameres, gonopore situated subapically.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4348BC680CD7FAA0FE0974C5.taxon	biology_ecology	Biology (Figs. 65, 69). Living in moist decaying plant material, such as rotten pseudostem of banana trunks, rotten bamboo or rotten figs.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4348BC680CD7FAA0FE0974C5.taxon	discussion	Remarks. Large-sized species (over 5 mm long). Orchymont (1925) described this species to have a distinct shagreen between ground punctures in the posterior half of the elytron. By observing specimens using a scanning electronic microscope, we that this “ shagreen ” is actujally formed by numerous micropunctures between ground punctures (Fig. 51). We examined other five large-sized species of Dactylosternum from the Orienal region. Dactylosternum dytiscoides (Fabricius, 1775) can be easily recognized by its reddish head, pronotum and scutellum (Fig. 71). The other four species (D. latum, D. salvazai, D. pseudolatum sp. nov. and D. frater sp. nov.) are all generally black, but can be distinguished from D. hydrophiloides by anterior margin of clypeus without distinct marginal rim (Figs 18, 19) (with marginal rim in D. hydrophiloides); ground punctures with associated microsculpture (Figs. 52 – 55) (ground punctures simple and interstices with dense micropunctures in D. hydrophiloides, Fig. 51); phallobase shorter than parameres (almost as long as parameres in D. hydrophiloides); and median lobe slender, reaching to subapical part of parameres (very short and broad, reaching only to the midlength of parameres in D. hydrophiloides, Fig. 24).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4348BC680CD7FAA0FE0974C5.taxon	distribution	Distribution. China (Fujian, Guangdong, Hong Kong, Hainan, Guangxi, Guizhou, Taiwan, Yunnan, Xizang) (this paper, Fikáček et al. 2015). New for Xizang, China. Outside China known from the following regions: Oriental: Bhutan, Nepal, India (West Bengal, Andaman Islands), Indonesia (Borneo, Buru, Java, Sulawesi), Malaysia (Malay Peninsula), the Philippines, Singapore, Thailand, Vietnam. Afrotropical (introduced): South Africa. Australian: Australia, Palau Island. Pacific (introduced): Hawaiian Island. Neotropical (introduced): Jamaica (Orchymont 1935, Hansen 1995).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	description	(Figs. 3, 11 – 13, 17, 23, 39, 42, 45, 49, 64, 66).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	materials_examined	Type material examined. HOLOTYPE: male (SYSU), Guangdong, Ruyuan County, Tianjingshan National Forest Park, 24 ° 43 ′ 19 ″ N 114 ° 2 ′ 51 ″ E, fallen rotten wood in forest, 589 m, 16. IV. 2020, Zuqi Mai, Baoping Huang & Zhaoyang Tang leg. PARATYPES: 1 male, 5 females (SYSU): same information as the holotype; 1 male, 1 female (SYSU), Jiangxi, Ganzhou, Jiulianshan National Reserve, Xiasongtang, 24 ° 32 ′ 28 ″ N 114 ° 27 ′ 32 ″ E, under fallen rotten wood, 526 m, 18. VIII. 2020, Zhenming Yang leg.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	diagnosis	Diagnosis. Length 4.2 – 4.5 mm, ca. 1.4 × as long as wide, widest at midlength. Body broadly oval, outline not parallel (Fig. 3), strongly convex (Figs. 12 – 13). Antenna yellow-brown with club black, club loosely segmented (Fig. 39). Surface of vertex, pronotum and elytron with fine punctures and microsculpture, each puncture connected with two short diverging lines forming a flying-bird-like impression (Fig. 45). Elytra slightly explanate in posterior half, sutural stria reaching ca. one-thirds of elytra posteriorly, with 10 rows of serial punctures, all nearly reaching elytral base. Posterior margin of ventrite 5 with a broad marginal bead. Aedeagus (Fig. 23): Parameres pointed at apex. Median lobe a little shorter than parameres, outer margin nearly parallel-sided in the medial, gradually narrowing apical, gonopore situated at apex.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	description	Description. Total length 4.2 – 4.5 mm (holotype: 4.3 mm); maximum width 2.7 – 2.8 mm (holotype: 2.75 mm); body broadly oval (Fig. 3), strongly convex (Figs. 12 – 13). Coloration. Dorsal black, with lateral margin of elytron slightly paler (Fig. 3). Maxillary palps and antenna yellowish brown with club black. Ventral black, mouthparts and legs reddish brown, tarsomeres reddish yellow (Fig. 11). Head. Clypeus weakly convex, surface with sparse, moderately coarse fine punctures, each puncture with a flying-bird-like microsculpture. Anterior margin of clypeus without marginal rim. Frontoclypeal suture weakly developed but distinct. Frons with punctures sparser than those on clypeus. Eyes of moderate size, nearly semicircular in dorsal view, separated by ca. 5.2 × as wide as one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with basistipes bearing sparse long setae. Maxillary palps stout, palpomere 2 swollen, thicker than the following two palpomeres, palpomere 4 with obtuse apex, ca. 1.3 × as long as penultimate. Mentum transverse, ca. 1.5 × as wide as long, widest between anterolateral corners, slightly narrowing posteriorly, bearing sparse long setae, surface of mentum deeply concave anteromedially, lateral sides with series of fine setae. Submentum black, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longer than other ones, a little narrower and and about 2 × as long as penultimate. Antennal scapus longest, rather thick, ca. 3.5 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, ca. 2 × as long as antennomere 4, antennomeres 4 and 5 almost equal in length, slightly widening distally, without any seta, club densely pubescent, with few long setae, loosely segmented, ca. 6 × as long as wide, antennomeres 7 and 8 almost equal in length, antennomere 9 symmetrical, ca. 1.8 × as long as penultimate. Prothorax. Pronotum transverse, strongly convex, arcuately narrowing anteriorly, anterolateral angles obtusely rounded, posterolateral angles almost rectangular, anterior and lateral margins with narrow marginal bead, pronotum surface with punctures similar to those on vertex (Fig. 45). Posterior margin slightly arcuate. Prosternum weakly tectiform medially, without median carina. Meso- and metathorax. Scutellum slightly wider than long, in shape of equilateral triangle, with fine punctures similar to those on pronotum. Elytron strongly convex, sutural stria reaching ca. one-third of elytra posteriorly, with 10 longitudinal serial punctures, all nearly reaching elytral base, series 1 – 6 consisting of very fine and sparse punctures, lateral four series with punctures larger and deeper than in inner six series, series 5 + 6 linked together subposteriorly. Elytral intervals with fine punctures similar with those on pronotum (Fig. 49). Elytral margin slightly explanate in posterior half. Hind wing (Fig. 17) well developed, with R-M loop widest at distal; RA 3 + 4 not attached to RA basally, forming a large opened radial cell; r 3 absent; r 4 present, connecting RA 3 + 4 to R-M loop; RA 3 short, well defined at apical portion; RA 4 fused with RP 1 forming a pigmented area, nearly reaching the margin of the wing apically, RP 1 attached to R-M loop basally; RP 2 forming a pigmented area wide on base, attached to R-M loop basally but not reaching the margin of the wing apically; RP 3 + 4 well developed, long and narrow, attached R-M loop basally, curved posteriorly and reaching wing margin apically; medial spur straight and sharp; MP 3 + 4 distinct, cambered, connected with MP 1 + 2, not attached to MP 3 apically; MP 3 and MP 4 + CuA 1 well defined, connected to basal portions of the veins proximally, reaching wing margin posteriorly; CuA 1 present, connect with MP 3 and MP 4 + CuA 1; CuA 2 well defined, reaching the posterior edge of the wing apically; AA 3 and AA 4 well defined, nearly reaching posterior margin of the wing; venation of anal field strongly reduced, composed of a short AP 3 + 4. Legs. Reddish brown, rather short. Procoxae globular, pubescent; profemora bearing dense pubescence throughout; protarsomeres with dense pubescence ventrally. Ventral surface of mesofemora covered with pubescence on marginal portion (Fig. 42), metafemora without pubescence, with fine punctures and sparse microsculptures; meso- and metatarsomeres with dense pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina. Posterior apex of ventrite 5 nearly truncate, with an incomplete marginal bead along margin. Male genitalia (Fig. 23). Aedeagus about 0.9 mm long, ca. 2.6 × as long as wide. Phallobase short, with manubrium short and rounded posteriorly. Parameres widest in the middle, gradually narrowing towards apex, outside slightly and smoothly curved. Median lobe a little shorter than parameres, wide throughout, ca. 3 × as long as phallobase, gradually narrowing apical, gonopore situated apically.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	etymology	Etymology. This species is named after the type locality, the Nanling Mountains.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	biology_ecology	Biology (Figs 64, 66). Specimens were collected from the surface of fallen wood in forest. The surface of the wood was wet and covered with thick layer of fulgal hyphae. Adults crawled quickly at the surface of the fallen wood.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	discussion	Remarks. This species is quite similar to D. cycloides Knisch, 1921 from Indonesia and Malaysia and D. auripes Fauvel, 1883 (Fig. 70) from New Caledonia. These two species also have a loose antennal club and highly convex body. This new species can be distinguished from D. cycloides by posterior margin of ventrite 5 with a broad marginal bead (marginal bead not distinct in D. cycloides), apex of median lobe rounded but sharper (with a duller apex in D. cycloides). It differs from D. auripes by shallower and finer serial punctures on elytron (strongly impressed punctures in D. auripes), inner 5 punctural series reaching elytral base (not reaching elytral base in D. auripes), median lobe rounded apically (apex truncate in D. auripes).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4347BC6D0CD7FBE4FD25741A.taxon	distribution	Distribution. China (Guangdong, Jiangxi).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4342BC6C0CD7FCA5FDA475C2.taxon	description	(Figs. 4, 22, 41, 43)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4342BC6C0CD7FCA5FDA475C2.taxon	materials_examined	Type material examined. HOLOTYPE: male (IZCAS), Guangxi, Napo, Nonghua, 750 m, 18. VIII. 1998, Fusheng Huang leg. PARATYPE: 3 females (SYSU): same information as the holotype.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4342BC6C0CD7FCA5FDA475C2.taxon	diagnosis	Diagnosis. Length 3.2 – 3.4 mm, widest in the middle. Body broadly oval, body outline not parallel-sided (Fig. 4), strongly convex. Body reddish brown to piceous brown. Antenna yellow-brown with club black, club loosely segmented. Anterior margin of clypeus pubescent, without marginal rim. Elytron with sutural stria reaching half of elytra, with 9 serial punctures, series 1 reaching basal third, series 2 – 3 reaching basal half, series 4 – 9 nearly reaching elytral base. Ventral surface of mesofemora bearing dense pubescence. Aedeagus (Fig. 22): Phallobase a little shorter than parameres (Jia 2002). Apex of parameres projecting slightly outwards. Median lobe a little shorter than parameres. Gonopore rounded, subapically.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4342BC6C0CD7FCA5FDA475C2.taxon	description	Redescription. Total length 3.2 – 3.4 mm; maximum width 2.0 – 2.1 mm; body broadly oval, strongly convex. Coloration. Reddish brown to piceous brown (Fig. 4), Ventral with the same color as dorsal; mouthparts, maxillary palps and labial palps reddish yellow; antenna reddish yellow with club black; legs with the same color as ventral but tarsomeres somewhat paler. Head. Clypeus weakly convex, surface with sparse and moderately strong punctures, anterior portion with denser punctures. Interstices between punctures smooth. Anterior margin of clypeus without marginal rim, bearing pubescence. Frons with punctures similar to those on clypeus, posterior margin of vertex with microsculpture between punctures. Eyes of moderate size, nearly semicircular in dorsal view, separated by ca. 5.5 × of the width of one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with basistipes bearing sparse long setae. Mentum transverse, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum yellowbrown pubescent. Labial palps rather stout. Antennal scapus longest, rather thick, ca. 3.5 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, antennomeres 4 and 5 almost equal in length, slightly widening distally, without any seta, club densely pubescent, with few long setae, loosely segmented. Prothorax. Pronotum moderately convex, widest basally, arcuately narrowed in front, with punctures similar to those on vertex (Fig. 43), posterior margin slightly arcuate, with narrow marginal bead. Prosternum strongly tectiform, with median carina and a distinct tooth anteromedially. Meso- and metathorax. Scutellum slightly longer than wide, apex rounded, in shape of isosceles triangle, with punctures similar to those on pronotum. Elytron ca. 1.45 × as wide as long, highly convex, sutural stria reaching half of elytra posteriorly, with 7 series of pigmented spots; each elytron with 9 longitudinal series of impressed punctures, with shallow fine ground punctures on intervals; series 1 reaching basal third, series 2 – 3 reaching basal half, series 4 – 9 nearly reaching elytral base. Inner 3 series with smaller punctures than outer seriesl; punctures in outer series becoming coarser gradually; the outer 4 serial punctures coarser and stronger than the inner 6 serial punctures; intervals of serial punctures with two sizes of punctures, the finer punctures similar to those on pronotum, the coarser punctures almost as coarse as those of the series that make it more or less difficult to separate the series posteriorly and laterally. Legs. Reddish brown to piceous brown. Procoxae globular, pubescent; profemora bearing dense pubescence throughout; protarsomeres pubescent ventrally. Mesofemora with dense pubescence (Fig. 43). Metafemora without pubescence, with sparse microsculpture; meso- and metatarsomeres with sparse pubescence ventrally. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex, with complete marginal bead. Posterior margin of ventrite 5 rounded, without stria. Male genitalia (Fig. 22). Aedeagus about 0.7 mm long. Phallobase slightly shorter than parameres. Parameres apex projecting slightly outwards, gradually narrowing. Median lobe ca. 0.8 × as long as parameres, apex rounded, gonopore rounded, situated at midlength.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4342BC6C0CD7FCA5FDA475C2.taxon	biology_ecology	Biology. Unknown.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4342BC6C0CD7FCA5FDA475C2.taxon	distribution	Distribution. China (Guangxi).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	description	(Figs. 5, 14 – 16, 44, 48)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	materials_examined	Type material examined. HOLOTYPE: female (SYSU), Guangxi, Jinxiu County, Yinshan Conservation Station, 24 ° 10 ′ 01 ″ N 110 ° 14 ′ 38 ″ E, lives with Hodotermopsis sjostedti in a fallen wood, 1200 m, 11. VII. 2014, Zhong Peng & Xiaobin Song leg.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	diagnosis	Diagnosis. Length 3.75 mm, widest in the middle. Body broadly oval, outline not parallel-sided (Fig. 5), strongly convex (Figs. 14 – 16). Antenna yellowish brown, club loosely segmented. Dorsal dark brown to black, Vertex, pronotum, scutellum and elytron with fine punctures, each puncture attached with a cambered microsculpture, forming flying-bird-like shape (Fig. 44). Elytron sutural stria reaching half of elytra, with 20 rows of serial punctures.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	description	Description. Total length 3.75 mm; maximum width 2.27 mm; body broadly oval, strongly convex. Coloration. Dorsal dark brown to black, with lateral margin of elytron reddish brown (Fig. 5). Maxillary palps and antenna yellowish brown. Ventral black, legs and mouthparts reddish brown, tarsomeres reddish yellow (Fig. 14). Head. Clypeus weakly convex, surface with two sizes of punctures, each puncture with a cambered microsculpture at margin, the coarser punctures attached with fine short microsculpture, finer punctures with long deep microsculpture, forming flying-bird-like shape. Anterior margin of clypeus without marginal rim. Frons with punctures sparser than those on clypeus. Eyes of moderate size, minimum interocular distance in dorsal view, ca. 5.2 × as wide as one eye, nearly semicircular in dorsal view, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with basistipes bearing sparse long setae. Mentum transverse, ca. 1.7 × as wide as long, bearing sparse setae, moderately concave anteromedially, lateral sides with series of fine setae. Submentum reddish brown, pubescent. Labial palps with three palpomeres, rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin. Antennal scapus longest, rather thick, ca. 2.6 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, ca. 2 × as long as antennomere 4, antennomeres 4 and 5 slightly widening distally, club with few long setae, loosely segmented, ca. 4.5 × as long as wide, antennomeres 7 and 8 almost equal in length, antennomere 9 symmetrical, ca. 2 × as long as penultimate. Prothorax. Pronotum transverse, strongly convex, widest basally, arcuately narrowed in front, anterolateral angles nearly indistinct, posterolateral angles obtusely rounded, surface with flying-bird-like shape microsculpture and punctures similar to those on vertex (Fig. 44). Prosternum moderately tectiform, without median carina. Meso- and metathorax. Scutellum slightly longer than wide, in shape of equilateral triangle, with punctures similar to those on pronotum. Elytron strongly convex, sutural stria reaching half of elytra, each elytron with 10 longitudinal primary serial punctures, all nearly reaching elytral base, with 10 shorter and more or less irregular secondary serial punctures that with similar size as primary series, intervals between series with sporadic trichobothria and shallow fine punctures that similar to those on vertex (Fig. 48). Legs. Reddish brown, rather short. Procoxae globular, pubescent; profemora bearing dense pubescence throughout; protarsomeres with dense pubescence ventrally. Ventral surface of mesofemora covered with pubescence on marginal portion. Metafemora without pubescence, with fine punctures and sparse microsculptures; meso- and metatarsomeres with dense pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex, with complete marginal bead. Posterior margin of ventrite 5 rounded, with a stria in front of the marginal bead.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	etymology	Etymology. This species is named after Mr. Song Xiao-bin, a specialist of staphylinid beetles of Shanghai Normal University, who collected and donated the specimen to us.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	biology_ecology	Biology. The single specimen collected from a decaying fallen wood living with termite Hodotermopsis sjostedti Holmgren, 1911.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	discussion	Remark. The specimen of D. songxiaobini sp. nov. collected with termites may be the first known termitophilous Dactylosternum. No other known species of Dactylostetnum has elytra with 20 rows (10 primary and 10 secondary) of serial punctures. Hence, although we have only examined one female, we are still confident that it represents a new species.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4341BC6E0CD7FF69FDA470B6.taxon	distribution	Distribution. China (Guangxi).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435EBC750CD7FF69FAA174E1.taxon	description	(Figs. 9, 30 – 38, 54, 58, 62)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435EBC750CD7FF69FAA174E1.taxon	materials_examined	Type material examined: Dactylosternum latum: SYNTYPES: 1 male (BMNH): “ Japan / Lewis // Sharp Coll / 1905 – 313 // Type // Cyclonotum latum / type D. S. // SYNTYPE / CYCLONOTUM / latum Sharp, 1873 / YN Minoshima det. 2021 ” (Figs 32, 34); 1 male (BMNH), “ Japan / G. Lewis / 1910 — 320 // Cyclonotum / latum / mihi D. S. // SYNTYPE / CYCLONOTUM / latum Sharp, 1873 / YN Minoshima det. 2021 ”. Dactylosternum vitalisi: HOLOTYPE: male (IRSNB): “ Laos: / Ban Sai / 8.12.1918 / Vitalis // Ban Sai / 8 - XII- 18 / No 2199 // TYPE // TYPE // A. d´Orchymont det. / Dactylosternum 1922 / Vitalisi d´Orchymont ” (Fig. 36); PARATYPE: 1 male (BMNH): “ Fokien // A. d’ Orchymont det / Dactylosternum 1922 / Vitalisi d’ Orchymont // Co-type // co- TYPE. ” Note. On the request of loan of the type specimens of D. latum, we received two Japanese specimens of Sharp collection from BMNH. Sharp (1873) mentioned that he examined two specimens, therefore they can be considered as syntypes. Both specimens are male, morphologically identical and with labels indicating that they are from Japan. The syntype status of both specimens does not cause any taxonomic confusion and we hence retain their status of syntypes. Additional material examined. CHINA: Anhui: 1 female (SYSU), Huangshan Prefecture, Tangkou County, Hougu, 13. VII. 2013, Qiu & Xu leg.; Guangxi: 1 male (HBUM), Tianlin County, Jiudongpin, 1200 – 1300 m, 27. V. 2002, Xiujuan Yang leg.; Hunan: 2 males, 1 female (HBUM), Shimen County, Huping Mountain, 17 – 20. VIII. 2004, Jianfeng Wang & Jiliang Wang leg.; 2 females (SYSU), Shimen County, Huping Mountain, Maozhuhe, 6. VI. 2017, Qiu & Xu leg.; 1 male (HBUM), Fenghuang County, Liangtouyang, 30. VII. 2004, Jishan Xu & Lingxiao Chang leg.; Yunnan: 1 male, 1 female (SYSU), Baoshan Prefecture, Gaoligong Natural Park, 24.91 ° N 98.81 ° E, 1751 m, 22. V. 2016, Yudan Tang & Ruijuan Zhang. Locality uncertain: 1 female (BMNH), “ China. // Sharp Coll. / 1905 - 313. ” [Note: Precise identification of the species without examination of aedeagus is difficult, but the specimen agrees with the type specimens in all external characters.]	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435EBC750CD7FF69FAA174E1.taxon	diagnosis	Diagnosis. Length 6.9 – 8.0 mm. Body oval, anterior half of elytra nearly parallel-sided (Fig. 9), moderately convex. Dorsal black, surface with fine punctures, comparatively shiny. Anterior margin of clypeus without marginal rim. Antenna yellow-brown, club compact. Elytra with sutural stria and ten distinct rows of serial punctures, all nearly reaching elytral base. Anteromedial portion of metaventral process with a strongly depressed pit (Fig. 58). Posterior margin of abdominal ventrite 5 with fine marginal bead, without stria behind the marginal bead (Fig. 62). Aedeagus (Figs. 30 – 38). Morphologically variable, phallobase shorter than parameres. Parameres slightly sinuate on outer margin. Median lobe widest in the basal one-fourths or at midlength, a little shorter than parameres; ventral plate of the median lobe almost parallel-sided in apical half, apex rounded, gonopore situated at apex of ventral plate (Figs. 30 c, 31 c), reaching ca. 0.8 of median lobe.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435EBC750CD7FF69FAA174E1.taxon	description	Redescription. Total length 6.9 – 8.0 mm; maximum width 4.5 – 4.8 mm; body oval, moderately convex. Coloration. Dorsal black, with lateral margin of elytron reddish brown (Fig. 9). Maxillary palps and antenna yellowish brown. Ventral black to reddish brown, legs reddish brown. Head. Clypeus weakly convex, surface with dense and fine punctures, anterior portion with denser punctures. Interstices between punctures smooth. Anterior margin of clypeus without marginal rim. Frons with punctures sparser than those on clypeus. Eyes of moderate size, separated by ca. 5 × as wide as one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with glabrous basistipes. Mentum transverse, glabrous, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum reddish brown, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longest. Antennal scapus longest, rather thick, ca. 7.5 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, antennomeres 4 and 5 almost equal in length, slightly widening distally, club densely pubescent, with few long setae, compact, ca. 2.5 × as long as wide. Prothorax. Pronotum moderately convex, widest basally, arcuately narrowed in front, with punctures sparser than those on vertex, interstices between punctures smooth; posterior margin slightly arcuate. Prosternum strongly tectiform, with median carina and a distinct tooth anteromedially. Meso- and metathorax. Scutellum distinctly longer than wide, apex rounded, in shape of isosceles triangle, with punctation similar to those on pronotum. Elytron moderately convex, sutural stria deeply impressed in posterior half; each elytron with 10 longitudinal serial punctures, deeply impressed in posterior half, intervals with fine ground punctures, each puncture attached with two short transverse microsculpture especially in posterior half (Fig. 54), series 3 + 4 and 6 + 7 linked together subposteriorly, others serial punctures reaching end of elytron, the outer 4 serial punctures larger and deeper than the inner 6 serial punctures. Anteromedial portion of metaventral process with a strongly depressed pit (Fig. 58). Legs. Reddish brown, rather short. Procoxae globular, pubescent; profemora without pubescence ventrally; protarsomeres unpubescent ventrally. Ventral surface of meso- and metafemora without pubescence, with sparse punctures and microsculptures; meso- and metatarsomeres with sparse pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex. Posteromedial portion of ventrite 5 unpubescent, with fine punctures, posterior margin of ventrite 5 rounded, with fine marginal bead, without stria (Fig. 62). Male genitalia (Figs. 30 – 38). Aedeagus around 1.2 mm long, ca. 2.7 × as long as wide. Phallobase shorter than parameres, with short manubrium and rounded posteriorly. Parameres widest basally, gradually narrowing toward apex, outer margin straight, slightly sinuate, slightly or strongly curved inwards apically. Median lobe ca. 0.8 – 0.9 × as long as parameres, widest in the basal 0.25 or at midlength, outer margin nearly parallel-side or slightly narrowing towards apex, rounded anteriorly, dully pointed apically; ventral plate of median lobe widest basally, almost parallelsided in apical half, apex rounded, gonopore situated at apex of ventral plate (Figs 30 c, 31 c), reaching ca. 0.8 of median lobe.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435EBC750CD7FF69FAA174E1.taxon	biology_ecology	Biology. Unknown. The species was considered as aquatic in the original description (Sharp 1873), based on the information from the collector (G. Lewis) that it is ‘ common in ponds’. Satô (1960) questioned the habitat of D. latum and suspected the species to be a synonym of D. hydrophiloides. We suspect that the habitat information in the original description was likely based on the confusion with some Coelostoma species which are common in Nagasaki, of the similar morphology, coloration and body size as D. latum, and are aquatic. All species of Dactylosternum known so far are terrestrial species (Hansen 1991; Fikáček 2010), including the other species treated here (D. frater, D. pseudolatum and D. salvarzai) which are very similar and likely rather closely related to D. latum. We hence assume that D. latum is a terrestrial species living in decaying plant material.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435EBC750CD7FF69FAA174E1.taxon	discussion	Remarks. This species was described based on two specimens collected by George Lewis in Japan. It had not been reported since the original description (Sharp 1873). Orchymont (1925) described D. vitalisi as a new species from Laos (type locality) and Fujian without examining the type specimens of D. latum. Dactylosternum vitalisi is also a large-sized species (more than 6 mm long) and is similar with D. latum. The examination of the holotype of D. vitalisi from Laos confirmed it represents the same species as the examined type specimens of D. latum. Surprisingly, the examined paratype of D. vitalisi is not identical to the holotype and is more similar to D. pseudolatum sp. nov., especially in the shape of aedeagus. This indicates the type series of D. vitalisi contains two species. We hence consider D. vitalisi is a junior synonym of D. latum. Variability. This species is morphologically variable, especially in the shape of aedeagus, as illustrated in Figs. 33 – 38.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435EBC750CD7FF69FAA174E1.taxon	distribution	Distribution. China (Anhui, Fujian, Hunan, Guangxi, Yunnan); Japan (Nagasaki, based on historical specimens only). New for China. Outside of China and Japan, the species if known from: Laos (Orchymont 1925).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	description	(Figs. 7, 19, 27 – 29, 52, 56, 60)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	materials_examined	Type material examined. HOLOTYPE: male (SYSU), Guangdong, Shaoguan Prefecture, Chebaling Nature Reserve, 23 ° 14 ′ 46 ″ N 113 ° 33 ′ 56 ″ E, 496 m, 28 – 29. V. 2017, Jia, Wang & Leung leg. PARATYPE: 1 male (IRSNB) “ Laos / 28.3.1918 / Vitalis // male symbol // co- / type // Para- / type // A. d´Orchymont det. / Dactylosternum 1922 / Vitalisi d´Orchymont ”; Fujian: 1 male (SYSU), Nanping City, Mangdangshan, 26 ° 41 ′ 51 ″ N, 118 ° 07 ′ 00 ″ E, mixed forest, leaf litter shifted, 400 m, 10. XI. 2015, Yan & Tang leg.; Guangdong, 7 spec. (SYSU), same information as the holotype; 1 male, Shaoguan Prefecture, Chebaling Nature Reserve, 23.7038 ° N 114.1914 ° E, 399 m, 27. V – 1. VI. 2019, XingminWang.; Hainan, 3 spec. (SYSU), Bawangling, Dongwu District, 8. V. 2011, Zhao leg.; 1 spec. (SYSU), Limushan, Limu Temple, 5. V. 2011, Zhao leg.; Jiangxi, 15 spec. (SYSU), Jinggangshan Prefecture, Xiangzhou, 26. IV. 2011, Jia leg.; 4 spec. (KMNH), Jinggangshan Prefecture, Xiangzhou, 26. IV. 2011, Jia leg.; 4 spec. (NMPC), Jinggangshan Prefecture, Xiangzhou, 26. IV. 2011, Jia leg.; Yunnan, 6 spec. (SYSU), Baoshan Prefecture, Baihualing, 25 ° 10 ′ N 98 ° 16 ′ E, 1516 m, 18. IV. 2015, Lin & Tang leg.; 1 spec. (SYSU), Xishuangbanna, Wangtianshu, 23. V. 2016, Lu Qiu leg.; 2 spec. (SYSU), Cheli, 600 m, 22. IV. 1957, Hong leg.; 2 spec. (SYSU), Xishuangbanna, 580 m, 22. IV. 1957, Pu leg.; 1 spec. (HBUM), Laiyanghe, Xinzhai village, 22.631 ° N 101.132 ° E, 1487 m, 21. V. 2011, Song leg.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	diagnosis	Diagnosis. Length 5.9 – 7.2 mm. Body oval, anterior half of elytra slightly parallel-sided (fig. 7), moderately convex. Dorsal black, surface with dense and fine punctures. Anterior margin of clypeus without marginal rim (Fig. 19). Antenna yellowish brown, club compact. Elytron with sutural stria and 10 distinct rows of serial punctures, all nearly reaching elytral base, ground punctures attached with one / two short transverse microsculptures. Anteromedial portion of metaventral process with a short transverse groove (Fig. 56). Posterior margin of ventrite 5 with distinct marginal bead and a stria behind the marginal bead (Fig. 60). Aedeagus (Figs. 27 – 29): Phallobase shorter than parameres. Parameres distinctly sinuate on outer margin, and strongly curved subapically. Median lobe widest in the middle, a little shorter than parameres; ventral plate triangular, strongly pointed at apex, gonopore situated at apex of ventral plate (Figs. 27 c, 28 c).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	description	Description. Total length 5.9 – 7.2 mm; maximum width 3.6 – 4.2 mm; body oval, moderately convex. Coloration. Dorsal black, with lateral margin of elytron reddish brown (Fig. 7). Maxillary palps and antenna yellowish brown. Ventral black to reddish brown, legs reddish brown. Head. Clypeus weakly convex, surface with dense and fine punctures, anterior portion with denser punctures. Interstices between punctures smooth. Anterior margin of clypeus without marginal rim (Fig. 19). Frons with punctures sparser than those on clypeus. Eyes of moderate size, separated by ca. 6 × as wide as one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with glabrous basistipes. Mentum transverse, glabrous, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum reddish brown, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longest. Antennal scapus longest, rather thick, ca. 7.5 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, antennomeres 4 and 5 almost equal in length, slightly widening distally, club densely pubescent, with few long setae, compact, ca. 2.5 × as long as wide. Prothorax. Pronotum moderately convex, widest basally, arcuately narrowed in front, with punctures sparser than those on vertex, interstices between punctures smooth; posterior margin slightly arcuate. Prosternum strongly tectiform, with median carina and a distinct tooth anteromedially. Meso- and metathorax. Scutellum distinctly longer than wide, apex rounded, in shape of isosceles triangle, with punctation similar to those on pronotum. Elytron moderately convex, sutural stria deeply impressed in posterior half; each elytron with 10 longitudinal serial punctures, deeply impressed in posterior half, intervals with fine ground punctures, each puncture with one / two short transverse lines especially in posterior half (Fig. 52); series 3 + 4 and 6 + 7 linked together subposteriorly, others serial punctures reaching end of elytron; lateral four series with punctures larger and deeper than those in the inner six series. Anteromedial portion of metaventral process with a short transverse groove (Fig. 56). Legs. Reddish brown, rather short. Procoxae globular, pubescent; profemora without pubescence ventrally; protarsomeres pubescent ventrally. Ventral surface of meso- and metafemora without pubescence, with sparse punctures and microsculptures; meso- and metatarsomeres with sparse pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex, with complete marginal bead. Posteromedial portion of ventrite 5 without pubescence, with fine punctures, posterior margin of ventrite 5 rounded, with a stria in front of the marginal bead (Fig. 60). Male genitalia (Figs. 27 – 29). Aedeagus about 1.1 mm long, ca. 2.2 × as long as wide. Phallobase shorter than parameres, with short manubrium and rounded posteriorly. Parameres strongly curved inwards apically, pointed at apex, sinuate on outer margin. Median lobe ca. 0.94 × as long as parameres, widest in the middle, gradually narrowing towards apex; ventral plate triangular, widest basally, tapering towards apex, strongly pointed at apex (Figs. 27 c, 28 c). Gonopore triangular, situated at apex of ventral plate, reaching ca. distal 0.8 of median lobe.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	etymology	Etymology. This species name is a combination of the Latin pseudo -, false, and the species name of Dactylosternum latum. The name refers to the fact that this species is quite similar to D. latum in morphology characters.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	biology_ecology	Biology. Living in moist plant material, such as decaying pseudostem of banana trunks and in leaf litter.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	discussion	Remarks. We examined two specimens of the type series of Dactylosternum vitalisi (the holotype and a paratype from Laos), in which we found several morphological differences. The holotype differs from the paratype in the morphology of the anterior part of the metaventral elevation, the mesoventral elevation, especially in the shapes of the aedeagus (compare Figs 29 and 36). This indicates that the holotype and paratype of D. vitalisi each represent a different species. The paratype of D. vitalisi is possibly represent an undescribed species. This new species is similar to D. salvazai Orchymont, D. latum (Sharp, 1873) and D. frater sp. nov. in both habitus and aedeagus morphology. It can be distinguished from the latter three species by dorsal surface with rather densely arranged fine punctures, less shiny (with sparser punctures on the dorsal surface and shiny in the latter three species). It can be distinguished from D. salvazai by anteromedial portion of metaventral process with a short transverse groove (Fig. 56) (anteromedial portion of metaventrite, behind metaventral process with a Λ-shape divergent ridge in D. salvazai, Fig. 57), each elytral ground puncture with one / two short transverse line especially in the posterior half of elytra (Fig. 52) (each puncture with a K / H-shape microsculpture in D. salvazai, Fig. 53), posteromedial portion of ventrite 5 with fine punctures (Fig. 60) (with mesh-like microsculpture instead of puncture in D. salvazai, Fig. 61), parameres distinctly sinuate on outer margin and more curved on lateral margin subapically (Figs. 27 – 29) (not sinuate and less curved on lateral margin subapically in D. salvazai, Figs. 25 a, b) and ventral plate of the median lobe strongly pointed apically (Figs 27 c, 28 c) (rounded at apex in D. salvazai, Fig. 25 c). The new species differs from D. latum and D. frater by anteromedial portion of metaventral process with a short transverse groove (Fig. 56) (with a strongly impressed pit in D. latum (Fig. 58) or slightly impressed pit in D. frater (Fig. 59 )), posterior margin of ventrite 5 with distinct marginal bead and a stria behind the marginal bead (Fig. 60) (with fine marginal bead and without stria in D. latum and D. frater; Figs. 62 – 63). Variability. Outer margin of parameres of the specimen from Hainan Island not so sinuated in apical twothirds as in specimens from other areas (Figs 28 a, b). In this aspect, the aedeagus of the Hainan specimens is almost the same as that of the paratype of D. vitalisi from Laos. The latter specimens also corresponds with the Chinese specimens of D. pseudolatum in external morphology. We hence treat the paratype of D. vitalisi as a paratype of D. pseudolatum herein.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE435ABC760CD7FBC0FB807669.taxon	distribution	Distribution. China (Guangdong, Jiangxi, Fujian, Hainan, Yunnan), Laos.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	description	(Figs. 10, 26, 55, 59, 63)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	materials_examined	Type material examined. HOLOTYPE: male (SYSU), Yunnan, Honghe Autonomous Prefecture, Luchun County, Pinghe Village, 28. VII. 2004, Jing Li & Caixia Yuan leg.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	diagnosis	Diagnosis. Length 7.1 mm. Body oval, anterior half of elytra nearly parallel-sided (Fig. 10), moderately convex. Dorsal black, surface with densely arranged fine punctures, comparatively shiny. Anterior margin of clypeus without marginal rim. Antenna yellow-brown, club compact. Elytron with sutural stria and ten distinct rows of serial punctures, all nearly reaching elytral base. Anteromedial portion of metaventral process with a slightly drepressed pit (Fig. 59). Posterior margin of ventrite 5 without marginal bead (Fig. 63). Aedeagus (Fig. 26): Phallobase shorter than parameres. Parameres slightly sinuate on outer margin. Median lobe a little shorter than parameres, apex pointed; gonopore situated apically.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	description	Description. Total length 7.1 mm; maximum width 4.1 mm; body oval, moderately convex. Coloration. Dorsal black, with lateral margin of elytron reddish brown (Fig. 10). Maxillary palps and antenna yellowish brown. Ventral black, legs reddish brown. Head. Clypeus weakly convex, surface with dense and fine punctures, anterior portion with denser punctures. Interstices between punctures smooth. Anterior margin of clypeus without marginal rim. Frons with punctures sparser than those on clypeus. Eyes of moderate size, separated by ca. 5 × as wide as one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with glabrous basistipes. Mentum transverse, glabrous, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum reddish brown, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longest. Antennal scapus longest, rather thick, ca. 7.5 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, antennomeres 4 and 5 almost equal in length, slightly widening distally, club densely pubescent, with few long setae, compact, ca. 2.5 × as long as wide. Prothorax. Pronotum moderately convex, widest basally, arcuately narrowed in front, with punctures sparser than those on vertex intervals without microculpture, posterior margin slightly arcuate. Prosternum strongly tectiform, with median carina and a distinct tooth anteromedially. Meso- and metathorax. Scutellum distinctly longer than wide, apex rounded, in shape of isosceles triangle, with punctures similar to those on pronotum. Elytron moderately convex, sutural stria deeply impressed in posterior half; each elytron with 10 longitudinal serial punctures, deeply impressed in posterior half, intervals with fine ground punctures, each puncture with two short transverse lines especially in posterior half (Fig. 55), series 3 + 4 and 6 + 7 linked together subposteriorly, other serial punctures reaching end of elytron, lateral four series with punctures larger and deeper than the inner six series. Anteromedial portion of metaventral process slightly depressed (Fig. 59). Legs. Reddish brown, rather short. Procoxae globular, pubescent; profemora without pubescence ventrally; protarsomeres not pubescent ventrally. Ventral surface of meso- and metafemora without pubescence, with sparse punctures and microsculpture; meso- and metatarsomeres with sparse pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex. Posteromedial portion of ventrite 5 not pubescent, with fine punctures, posterior margin of ventrite 5 rounded, without marginal bead and stria (Fig. 62). Male genitalia (Fig. 26). Aedeagus 1.26 mm long, ca. 3.2 × as long as wide. Phallobase shorter than parameres, with short, rounded manubrium posteriorly. Parameres slightly curved inwards apically, pointed at apex, slightly sinuate on outer margin. Median lobe ca. 0.8 × as long as parameres, widest in the basal 0.25, gradually narrowing towards apex, pointed apically; ventral plate slender, widest basally, almost parallel-sided in apical half (Fig. 26 c). Gonopore triangular, reaching subapical of median lobe.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	etymology	Etymology. This new species is derived from the Latin adjective frater, meaning a brother, reflecting that this species is very similar to the other three species in China: Dactylosternum salvazai Orchymont, 1925, D. pseudolatum sp. nov. and D. latum (Sharp, 1873).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	biology_ecology	Biology. Unknown.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	discussion	Remarks. This species is very similar to Dactylosternum latum (Sharp). It can be distinguished from the latter by anteromedial portion of metaventral process slightly drepressed pit (Fig. 59) (with a strongly depressed pit in D. latum (Fig. 58 )), gonopore reaching apical of median lobe (Fig. 26) (gonopore reaching ca. 0.8 of median lobe in D. latum (Figs. 30 – 38 ))	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4356BC780CD7FA43FDA97105.taxon	distribution	Distribution. China (Yunnan).	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4357BC7A0CD7F9B1FB2477BD.taxon	description	(Figs. 8, 25, 53, 57, 61)	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4357BC7A0CD7F9B1FB2477BD.taxon	materials_examined	Type material: not examined. Material examined. CHINA: Yunnan: 1 male (SYSU), Gaoligong Mountain, 2000 m, 23. VII. 2012, Jishan Xu & Lingxiao Chang leg.; 4 spec. (SYSU), Yingjiang County, Xima Town, 2000 m, light trap, VI. 2019, Zhaoyang Tang leg. Additional material examined. LAOS: 1 female (SMNH), Hua Phan Prov., Ban Saluei, Phu Phan Mt., 20 ° 15 ′ N, 104 ° 02 ′ E, 1500 – 2000 m, 26. IV – 11. V. 2001, J. Bezděk leg., coll. H. Hebauer, Dactylosternum salvazai Orch., det. F. Hebauer.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4357BC7A0CD7F9B1FB2477BD.taxon	diagnosis	Diagnosis. Length 7.3 mm. Body broadly oval, slightly parallel-sided in anterior half of elytra (Fig. 8), moderately convex. Dorsal black, surface with fine punctures, comparatively shiny. Anterior margin of clypeus without marginal rim. Antenna brown, club compact. Elytron with sutural stria and ten distinct rows of serial punctures, all nearly reaching elytral base, serial punctures with reticulation in ca. posterior half, intervals of serial punctures with fine ground punctures, each puncture with a K / H-shape microsculpture especially in posterior half (Fig. 53). Anteromedial portion of metaventrite, behind metaventral process with a Λ- shape divergent ridge (Fig. 57). Posteromedial portion of ventrite 5 with mesh-like microsculpture, posterior margin of ventrite 5 with a stria behind the marginal bead, with median group of strong setae along marginal bead (Fig. 61). Aedeagus (Fig. 25): Phallobase shorter than parameres. Outer margin of parameres slightly and continuously convex, not sinuate. Median lobe a little shorter than parameres; ventral plate of the median lobe triangular, apex rounded, gonopore situated at apex of ventral plate (Fig. 25 c), reaching almost apex of median lobe.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4357BC7A0CD7F9B1FB2477BD.taxon	description	Redescription. Total length 7.3 mm; maximum width 4.8 mm; body broadly oval, moderately convex. Coloration. Dorsal black, with lateral margin of elytron reddish brown (Fig. 8). Maxillary palps and antenna brown. Ventral black, legs reddish brown. Head. Clypeus weakly convex, surface with dense and fine punctures, anterior portion with denser punctures. Interstices between punctures smooth. Anterior margin of clypeus without marginal rim. Frons with punctures sparser than those on clypeus. Eyes of moderate size, separated by ca. 5 × as wide as one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with glabrous basistipes. Mentum transverse, glabrous, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum reddish brown, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longer than other ones. Antennal scapus longest, rather thick, ca. 7.5 × as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, antennomeres 4 and 5 almost equal in length, slightly widening distally, club densely pubescent, with few long setae, compact, ca. 2.5 × as long as wide. Prothorax. Pronotum moderately convex, widest basally, arcuately narrowed in front, with punctures sparser than those on vertex, interstices between punctures smooth; posterior margin slightly arcuate. Prosternum strongly tectiform, with median carina and a distinct tooth anteromedially. Meso- and metathorax. Scutellum longer than wide with rounded apex, in shape of isosceles triangle, with punctation similar to those on pronotum. Elytron moderately convex, sutural stria deeply impressed in posterior half; each elytron with 10 longitudinal serial punctures, deeply impressed in posterior half; intervals with fine ground punctures, each puncture with a K / H-shape microsculpture especially in posterior half of elytra (Fig. 53); series 3 + 4 and series 6 + 7 linked together subposteriorly, others serial punctures reaching end of elytron, lateral four series with punctures larger and deeper than the inner six series, around serial punctures with reticulation especially in posterior half. Mesoventrite with a Λ-shape divergent ridge at anteromedial portion, behind metaventral process (Fig. 57). Legs. Reddish brown, rather short. Procoxae globular, pubescent; profemora without pubescence ventrally; protarsomeres without pubescence ventrally. Ventral surface of meso- and metafemora without pubescence, with sparse punctures and microsculpture; meso- and metatarsomeres with sparse pubescence ventrally, almost equal in length. Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex, with complete marginal bead. Posteromedial portion of ventrite 5 wirhout pubescence, with mesh-like microsculpture, posterior margin of ventrite 5 rounded, with a stria in front of the marginal bead (Fig. 61). Male genitalia (Fig. 25). Aedeagus about 1.15 mm long, ca. 2.4 × as long as wide. Phallobase shorter than parameres, with short manubrium and rounded posteriorly. Parameres widest basally, gradually narrowing toward apex, outer margin slightly and continuously convex, incurved apically, inner margin almost truncate apically. Median lobe ca. 0.83 × as long as parameres, widest in the basal 0.25, gradually narrowing towards apex; ventral plate of the median lobe triangular, widest basally, tapering towards apex, apex rounded, gonopore situated at apex of ventral plate (Fig. 25 c), reaching almost apex of median lobe.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4357BC7A0CD7F9B1FB2477BD.taxon	biology_ecology	Biology. Unknown.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4357BC7A0CD7F9B1FB2477BD.taxon	distribution	Distribution. China (Yunnan); Laos (Orchymont 1925). New for China.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4357BC7A0CD7F9B1FB2477BD.taxon	discussion	The species of D. salvazai and closed species can be distinguished using following table.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
03F687FE4352BC7C0CD7F884FD5674A9.taxon	description	Dactylosternum latum was described based on the Japanese specimens, but the occurence of the species in Japan is questionable. Three possibilities arise from this and previous studies: (1) the type specimens were mislabelled; (2) the species is extremely rare or occurs in uncommon habitats, and thus it has been overlooked; or (3) this species has already become extinct in Japan. Mislabelled specimens are not rare in any collection, and mislabelling would imply that the actual collection locality is outside Japan. Similar cases have been recognized in some Japanese beetles collected in Nagasaki by G. Lewis; for example, Tenebrio alternicostis Marseul, 1876 (Tenebrionidae) and Eotrichia niponensis (Lewis, 1895) (Marseul 1876; Lewis 1895) have never been collected in Japan since the original description at present (Kobayashi 1982; Akita & Masumoto 2016); the latter species was also recorded from Russian Far East and China (Bezděk 2016). On the request of the loan of the type specimens, we also received one additional unidentified female specimen of Chinese Dactylosternum from D. Sharp collection in NHM. The specimen is identical to D. latum in dorsal and ventral external characters and there is a high probability that it belongs to the species. Moreover, we found additional specimens of D. latum from China. These findings raise the possibility that D. latum may be native to south China and Laos and the real origin of the type specimens of C. latum is China. Alternatively, habitat loss associated with environmental destruction has long been serious in Japan as well as in other biodiversity hotspots. It is not impossible that the species has already become extinct or is exceedingly rare at present. Dactylosternum latum has been neglected and it has never been figured in any literature. Hence, it is still possible that it has been overlooked and is preserved in cabinets as unidentified Coleoptera. Beetle fauna has been rather well studied in Japan; it is therefore difficult to assume that no entomologist has ever encountered D. latum over the past 150 years. Moreover, Dactylosternum is a terrestrial lineage (Hansen 1991), and its occurrence in aquatic habitats is questionable. We therefore consider the possibility that the locality as well as the habitat data are doubtful. However, at present, we cannot rule out any possibilities based on our poor knowledge of the species. We expect that this study may help to discover more recently collected specimens and help us to understand the distribution of the species.	en	Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong, Fikáček, Martin (2022): Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae). Zootaxa 5091 (2): 269-300, DOI: https://doi.org/10.11646/zootaxa.5091.2.3
