Revision of the Seashore-dwelling Subgenera Emplenota Casey and Triochara Bernhauer (Coleoptera: Staphylinidae: genus Aleochara) from Japan Author Yamamoto, Shûhei Author Maruyama, Munetoshi text Zootaxa 2012 3517 1 52 journal article 10.5281/zenodo.282595 3c0b0572-9d83-492a-8656-229c8b2043a3 1175-5326 282595 F832C768-A8CA-4FEE-8C3B-BD933247FA6E Aleochara ( Emplenota ) segregata Yamamoto & Maruyama n. sp. ( Figs. 5 , 30–37 , 93–94, 97 , 102 ) “ Aleochara ( Emplenota ) fucicola Sharp, 1874 ”; Ahn et al ., 2000 : 243 (diagnosis with figures; later regarded as misidentification of “ A. puetzi ” by Park & Ahn, 2004 , but actually misidentification of A. segregata ; re-examination of specimens is needed). “ Aleochara ( Emplenota ) puetzi Assing, 1995 ”; Park & Ahn, 2004 : 195 (key to littoral Aleochara species of Korea ), 196 (redescription, but misidentification of A. segregata ; re-examination of specimens is needed). Type series. Holotype , 3, JAPAN : Ikinomatsubara-1chôme, Nishi-ku, Fukuoka-shi, Fukuoka-ken, Kyûshû ( 33.580N , 130.293E ), 28 VI 2009 , Yamamoto-S. (collected by an aspirator; from drafted seaweed on fine sandy beach in day time; KUM). Paratypes , JAPAN : [Hokkaidô] : 1 Ƥ, Matue (Okushiri-tô), Okushiri-chô, Okushiri-gun ( 42.072N , 139.471E ), 12 VII 2008 , Ôhara-M. (42°04ʹ18ʺN, 139°28ʹ17ʺE; under seaweed; 5 3, 6 Ƥ, Sawara, Mori-machi, Kayabe-gun ( 42.123N , 140.647E ), 15 VII 2009 , Ôhara-M. (42°07ʹ23ʺN, 140°38ʹ50ʺE; under seaweed ( Sargassum sp.); HUM : HK-09-MO-040/SA); HUM : HK-09-MO-032/SA); 2 3, Esashi-chô, Hiyama-gun ( 41.857N , 140.125E *), 4 VI 1977 , Nishikawa-N. (KUM); 1 Ƥ, Hakodate-shi ( 41.760N , 140.693E *), 13 V 1971 , Hirano-Y. (KUM); 1 3, 1 Ƥ, Hon-chô, Kikonai-chô, Kamiiso-gun ( 41.676N , 140.439E ), 12 VII 2009 , Ôhara-M. (41°40ʹ33ʺN, 140°26ʹ22ʺE; under seaweed ( Laminaria sp., Sargassum sp.) and eel grass ( Zostera sp.); HUM : OK- 08-MO-015). [Honshû] : 1 3, Rikuchû-Yagi, Taneichi, Hirono-chô, Kunohe-gun ( 40.349N , 141.764E ), 28 VI 2010 , Ôhara-M. (40°20ʹ56ʺN, 141°45ʹ49ʺE; under seaweed ( Laminaria sp., Sargassum sp.) and eel grass ( Zostera sp.) on sandy beach: HUM : HN-10-MO-044/SA); 2 Ƥ, Raga, Tanohata-mura, Shimohei-gun, Iwate-ken ( 39.939N , 141.940E *), 30 V 1998 , Watanabe-T. (cWat); 1 3, Jôdoga-hama, Hitachihama-chô, Miyako-shi, Iwate-ken ( 39.649N , 141.981E ), 29 V 1998 , Watanabe-T. (cWat); 3 Ƥ, Isohara, Kitaibaraki-shi, Ibaraki-ken ( 36.790N , 140.752E ), 24 V 1998 , Ohmomo-S. (KUM); 1 3, Majima, Murakami-shi, Niigata-ken ( 38.273N , 139.449E *), 5 V 2000 , no collector’s name (KUM); 1 Ƥ, Benten-misaki (Sadoga-shima), Higashikowashimizu, Sado-shi, Niigataken ( 38.008N , 138.546E ), 4 V 1998 , Kinoshita-T. (cWat); 1 3, same data, 5 V 1998 , Tsuyuki-S. (cWat); 1 3, Hamaogi-kaigan, Hamaogi, Kamogawa-shi, Chiba-ken ( 35.118N , 140.144E ), 24 IV 1990 , Takeda-T. (KUM); 1 3, 1 Ƥ, same data, but 6 IV 1993 ; 2 3, 1 Ƥ, Heisaura, Sakai, Tateyama-shi, Chiba-ken ( 34.948N , 139.801E ), 1 IV 1997 , Maruyama-M. (cMar); 1 Ƥ, Shinmaiko-hama, Yawata, Futtsu-shi, Chiba-ken ( 35.250N , 139.866E ), 11 VI 1995 , Emoto-K. (cWat); 5 3, 4 Ƥ, Shibasaki-bashi bridge, Kanaya, Futtsu-shi, Chiba-ken ( 35.174N , 139.819E ), 14 VI 2009 , Ono-H. (cOno); 1 3, 1 Ƥ, Kaneda swimming beach, Kaneda , Minamishitaura-machi, Miura-shi, Kanagawa-ken ( 35.167N , 139.660E ), 19 III 2001 , Watanabe-T. (cWat); 2 3, 2 Ƥ, Jôgashima (Jôga-shima), Misakimachi, Miura-shi, Kanagawa-ken ( 35.132N , 139.621E ), 10 IV 2003 , Watanabe-T. (cWat); 1 Ƥ, Mito beach, Hassemachi, Miura-shi, Kanagawa-ken ( 35.177N , 139.620E ), 29 V 2007 , Watanabe-T. (cWat); 5 3, 4 Ƥ, same data, but 5 VI 2007 ; 1 3, 1 Ƥ, same data, but 14 V 2009 (collected with Aleochara ( E .) hayamai ); 3 3, 1 Ƥ, same data, but 12 VI 2009 ; 3 3, 1 Ƥ, Arasaki, Nagai, Yokosuka-shi, Kanagawa-ken ( 35.194N , 139.600E *), 12 VI 2009 , Watanabe-T. (cWat); 1 3, 3 Ƥ, Shônan-kaigan, Kanagawa-Ken ( 35.315N , 139.351E *), 2 VII 1976 , Niizato (KUM); 1 3, Eno-shima, Fujisawa-shi, Kanagawa-ken ( 35.300N , 139.485E *), 11 VI 2001 , Watanabe-T. (cWat); 1 3, 3 Ƥ, Mitsuishi, Manazuru, Manazuru-shi, Ashigarashimo-gun, Kanagawa-ken ( 35.138N , 139.163E ), 15 VII 1989 , Watanabe-T. (cWat); 2 3, Shira-hama, Shirahama, Shimoda-shi, Shizuoka-ken ( 34.689N , 138.973E ), 13 III 1989 , Oda-H. (KUM); 33 3, 18 Ƥ, Tsumeki-zaki, Shimoda-shi, Shizuoka-ken ( 34.659N , 138.987E ), 21 IV 2003 , Maruyama-M. (cMar); 1 3, 1 Ƥ, river mouth of Kushida-gawa, Matsunase-chô, Matsuzaka-shi, Mie-ken ( 34.605N , 136.581E ), 29 IV 2002 , Kawakami-Y. (cKaw); 1 3, Maizuru, Kyôto-fu ( 35.514N , 135.387E *), 3 V 1980 , Hayashi-Y. (cHayas); 1 3, Shimakage, Miyazu-shi, Kyôto-fu ( 35.576N , 135.250E *), 31 III 2000 , Yasukawa- K. (KUM); 1 Ƥ, Shionomisaki, Kushimoto-chô, Higashimuro-gun, Wakayama-ken ( 33.445N , 135.756E *), 17 V 1964 , Yasui-M. (cHayas); 1 Ƥ, Kada-kaigan, Kada, Wakayama-shi, Wakayama-ken ( 34.280N , 135.074E ), 4 IX 2003 , Wada-T. (KUM); 1 Ƥ, Niriga-hama, Isonoura, Wakayama-shi, Wakayama-ken ( 34.259N , 135.094E ), 15 V 2007 , Kawakami-Y. (cKaw); 1 Ƥ, river mouth of Ashiya-gawa, Minamihama-chô, Ashiya-shi, Hyôgo-ken ( 34.708N , 135.309E ), 27 V 1998 , Kawakami-Y. (cKaw); 1 3, Sumaura-kaigan, Sumauradôri, Suma-ku, Kôbe-shi, Hyôgo-ken ( 34.637N , 135.103E ), 16 VI 1998 , Kawakami-Y. (cKaw); 1 Ƥ, same data, but 15 IV 2004 ; 4 3, same data, but 27 V 2010 ; 2 3, 1 Ƥ, Maiko-hama, Tarumi-ku, Kôbe-shi, Hyôgo-ken ( 34.638N , 135.027E ), 16 VI 1998 , Kawakami-Y. (cKaw); 2 3, Nada-kaigan (Awaji-shima), Nada, Minamiawaji-shi, Hyôgo-ken ( 34.207N , 134.812E *), 1 IV 1977 , Kaneda (KUM); 1 Ƥ, same locality, but 3 X 1972 , Tomokuni-M. and Sakai-M. ( EEEU ); 1 3, Gunge-hama (Awaji-shima), Gunge, Awaji-shi, Hyôgo-ken ( 34.475N , 134.845E ), 5 V 2000 , Kawakami-Y. (cKaw); 2 3, 1 Ƥ, Sumoto coast (Awaji-shima), Sumoto-shi, Hyôgo-ken ( 34.343N , 134.902E *), 23 V 1998 , Kawakami-Y. (cKaw); 1 Ƥ, river mouth of Akashi-gawa, Akashi, Akashi-shi, Hyôgo-ken ( 34.644N , 134.975E ), 9 IV 2002 , Kawakami-Y. (cKaw); 1 Ƥ, Yagi, Ôkubo-chô, Akashi-shi, Hyôgo-ken ( 34.670N , 134.933E ), 9 V 1999 , Kawakami-Y. (cKaw); 1 3, Matogata beach, Matogata, Matogata-chô, Himeji-shi, Hyôgo-ken ( 34.769N , 134.746E ), 16 V 2010 , Kawakami-Y. (KUM); 1 3, Fukudomari, Matogata-chô, Himeji-shi, Hyôgo-ken ( 34.769N , 134.737E ), 2 VI 2000 , Kawakami-Y. (cKaw); 1 Ƥ, Shirahama, Shirahama-chô, Himeji-shi, Hyôgo-ken ( 34.777N , 134.708E ), 2 VI 2000 , Kawakami-Y. (cKaw); 1 3, 3 Ƥ, river mouth of Chigusa-gawa, Onzaki, Akô-shi, Hyôgoken ( 34.731N , 134.393E ), 15 VI 1999 , Kawakami-Y. (cKaw); 1 3, 1 Ƥ, Kugui, Higashi-ku, Okayama-shi, Okayama-ken ( 34.584N , 134.086E *), 31 III 2003 , Fujitani-Y. (KUM); 5 3, 2 Ƥ, same data, but 9 V 2003 (under seaweed on beach); 3 3, 2 Ƥ, same data, but 28 V 2003 ; 1 3, Inazumi, Sugeura, Mihonoseki-chô, Matue-shi, Shimane-ken ( 35.564N , 133.166E *), 1-2 VI 2008 , Hayama-T. (sandy beach; cHayam); 2 3, Okidomari, Tako, Shimane-chô, Matue-shi, Shimane-ken ( 35.604N , 133.096E *), 3 VI 2008 , Hayama-T. (from seaweed; cHayam); 2 3, Konami-kaigan, Nonami, Shimane-chô, Matue-shi, Shimane-ken ( 35.588N , 133.098E ), 6 V 2008 , Hayama-T. (cHayam); 1 Ƥ, Kakanokuketo, Shimane-chô, Matsue-shi, Shimane-ken ( 35.578N , 133.050E ), 9 VI 2009 , Hayama-T. (cHayam); 1 Ƥ, same data, but 19 VII 2010 , Yamamoto-S. (shingle beach; under flotsom; cYam); 41 3, 56 Ƥ, Koura-kaigan, Koura, Kashima-chô, Matue-shi, Shimane-ken ( 35.5201N , 132.975E ), 8-10 VI 2009 , Hayama-T. (FIT; cHayam); 2 Ƥ, same data, but 3-5 VII 2009 ; 12 3, 36 Ƥ, same data, but 18-20 VI 2009 ; 1 3, 1 Ƥ, same data, but 16-18 VII 2009 ; 3 3, 1 Ƥ, same locality, but 17 VII 2010 , Yamamoto-S. (under flotsam on sandy beach; cYam); 1 3, same data, but 18 VII 2010 ; 2 Ƥ, Sakaura-kaigan, Sakaura-chô, Izumo-shi, Shimane-ken ( 35.508N , 132.861E ), 4 VII 2008 , Hayama-T. (shingle beach with shore reefs; cHayam); 1 3, same data, but 15 IV 2009 (from seaweed); 1 3, 4 Ƥ, same data, but 20 IV 2009 ; 1 3, river mouth of Sakaura-gawa, Sakaura-chô, Izumo-shi, Shimane-ken ( 35.508N , 132.861E ), 24 III 2009 , Hayama-T. (shingle beach; cHayam); 1 3, river mouth of Mitsu-gawa, Mitsu-chô, Izumo-shi, Shimane-ken ( 35.498N , 132.826E ), 30 IV 2008 , Hayama-T. (cHayam); 2 Ƥ, river mouth of Inome-gawa, Inome-chô, Izumo-shi, Shimane-ken ( 35.441N , 132.710E ), 21 III 2008 , Hayama-T. (shingle beach; cHayam); 5 3, Owashi-hama, Nakayama, Taisha-chô, Izumo-shi, Shimane-ken ( 35.433N , 132.634E ), 10 IV 2009 , Hayama-T. (cHayam); 2 3, Akaishihana, Hinomisaki, Taisha-chô, Izumo-shi, Shimaneken ( 35.411N , 132.650E *), 2 IV 2009 , Hayama-T. (cHayam); 2 3, same data, but 2-8 V 2009 (FIT; cHayam); 1 Ƥ, Sotozono-kaigan, Sashiumi, Koryô-chô, Izumo-shi, Shimane-ken ( 35.333N , 132.664E ), 12-13 IV 2009 , Hayama- T. (YPT; cHayam); 2 3, Kumura-kaisuiyokujô swimming beach, Kumura, Taki-chô, Izumo-shi, Shimane-ken ( 35.296N , 132.637E ), 5 X 2008 , Hayama-T. (cHayam); 2 3, 1 Ƥ, Kumura, Taki-chô, Izumo-shi, Shimane-ken ( 35.296N , 132.637E *), 18 IV 2009 , Hayama-T. (cHayam); 1 3, Kuchitaki, Taki-chô, Izumo-shi, Shimane-ken ( 35.271N , 132.581E ), 18 IV 2009 , Hayama-T. (cHayam); 1 3, 1 Ƥ, Iwami-kaigan, Kushiro-chô, Hamada-shi, Shimane-ken ( 34.955N , 132.127E *), 16-17 VI 2008 , Hayama-T. (YPT; cHayam); 1 3, 1 Ƥ, Kiami-chô, Masudashi, Shimane-ken ( 34.676N , 131.750E *), 15 VI 2008 , Hayama-T. (cHayam); 2 3, 1 Ƥ, same data, but 15-16 VI 2008 (FIT); 1 3, 1 Ƥ, same data, but 10 V 2009 ; 7 Ƥ, same data, but 10-11 V 2009 (FIT); 7 3, 11 Ƥ, Yoshimi, Shimonoseki-shi, Yamaguchi-ken ( 34.064N , 130.905E *), 1 VI 1980 , Naomi-S.I. (KUM). [Shikoku] : 3 3, 5 Ƥ, Ariake-hama, Muromoto-chô, Kanonji-shi, Kagawa-ken ( 34.139N , 133.642E ), 9 IV 2011 , Fujimoto-H. (sandy beach; KUM); 21 3, 10 Ƥ, Iwagi (Akahone-jima), Kamijima-chô, Ochi-gun, Ehime-ken ( 34.234N , 133.159E *), 2 V 2009 , Satô-Y. ( EEEU ); 3 Ƥ, same locality, but 7 V 2009 , Senda-Y. ( EEEU ); 1 Ƥ, Hôjôtsuji, Matsuyama-shi, Ehime-ken ( 33.974N , 132.770E ), 16 VI 2008 , Senda-Y. ( EEEU ). [Kyûshû] : 3 3, 4 Ƥ, Watari, Fukutsu-shi, Fukuoka-ken ( 33.786N , 130.454E ), 21 IV 2012 , Yamamoto-S., Maruyama-M., Kanao-T. (from seaweed on small sandy beach with Aleochara ( Triochara ) trisulcata ; KUM); 4 3, 6 Ƥ, Watari, Fukutsu-shi, Fukuoka-ken ( 33.790N , 130.447E ), 21 IV 2012 , Yamamoto-S., Maruyama-M., Kanao-T. (from seaweed on huge sandy beach with A. ( T. ) trisulcata ; KUM); 1 Ƥ, Mitoma, Higashi-ku, Fukuoka-shi, Fukuoka-ken ( 33.703N , 130.417E ), 3 VI 2001 , Ogata- S. (KUM); 2 3, 1 Ƥ, Shikano-shima, Higashi-ku, Fukuoka-shi, Fukuoka-ken ( 33.675N , 130.312E *), 24 VIII 1980 , Naomi-S.I. (KUM); 3 3, 1 Ƥ, Shimomaga-hama, Katsuma, Higashi-ku, Fukuoka-shi, Fukuoka-ken ( 33.684N , 130.290E ), 15 V 2011 (11:30), Yamamoto-S. (seaweed on sandy beach together with A. ( T. ) trisulcata ; cYam); 25 3, 56 Ƥ, same data, but 9 VII 2011 (15:00-16:00; from seaweed and flotsam on beach); 28 3, 39 Ƥ, same data, but 21 III 2012 (14:00); 3 3, 7 Ƥ, Odo-kôen park, Odo-2chôme 6, Nishi-ku, Fukuoka-shi, Fukuoka-ken ( 33.596N , 130.311E ), 28 VI 2009 , Yamamoto-S. (from decaying seaweed along sandy seashore; cYam); 24 3, 26 Ƥ, Ikinomatsubara-1chôme, Nishi-ku, Fukuoka-shi, Fukuoka-ken ( 33.580N , 130.293E ), 28 VI 2009 , Yamamoto-S. (from seaweed on sandy beach; same data as holotype ; cYam); 3 3, 6 Ƥ, Noko (Nokono-shima), Nishi-ku, Fukuoka-shi, Fukuoka-ken ( 33.608N , 130.299E ), 20 III 2009 , Yamamoto-S. (from a seaweed mass on sandy beach with A. ( T. ) trisulcata and A . ( T .) zerchei ; cYam]; 1 Ƥ, Hongô (Sakito-jima), Sakito-chô, Saikai-shi, Nagasaki-ken ( 33.003N , 129.550E *), 23 X 1977 , Imasaka-S. (KUM). [Ryûkyû] : 1 Ƥ, Nakatane-chô (Tanega-shima), Kumagegun, Kagoshima-ken ( 30.515N , 130.980E ), 8-13 V 1996 , Maruyama-M. (cMar). Description. Body ( Fig. 5 ): medium to relatively large size, normally medium sized. Uniformly densely haired except for head along midline; surface of pronotum and elytra covered with numerous somewhat long hairs densely; head, pronotum and elytra with distinct punctures on dorsal surface densely. Colour ( Fig. 5 ): gland colour blackish brown to dark gray; legs, especially tarsal segments, reddish brown to dark brown: maxillary and labial palpi reddish brown to yellowish brown; antennae blackish brown and partly reddish brown. Head : head capsule somewhat rectangle; surface entirely rather flattened, but impunctured area along midline longitudinally swollen (weakly carinate); surface sparsely covered with thin and somewhat long setae except for swollen area; uniformly observed comparatively large hexagonal reticulations on dorsal surface. Antennae : moderately thick and long; segment I, nearly 2.1 times as long as broad; segment II clearly shorter than I; segment III as same length as II; segment IV spherical or short barrel shape, as long as width; segments V and VI short barrel shape; sebments VII to X clearly transverse; segment XI, about 1.6 times as long as broad; relative length (width) of segments from basal to apical: 10.5(5): 7(4): 7(4): 4(4): 4.5(5): 4.5(5): 4(5): 3.5(5): 4(6): 4.5(6): 9(5.5). Thorax : pronotum somewhat wider than long (PW/PL =1.24), a little broader than head (PW/HW =1.36); surface mat with large hexagonal reticulations with somewhat shallow distinct punctures. Metaventrite, about 1.5 times as long as mesoventrite. Apex of inter coxal process of mesoventrite sharply pointed with very short and inconspicuous carina along midline, about 0.3 times as long as mesoventrite. Inter coxal process of metaventrite very broad and short, less than one third as long as mesocoxal cavity, and rounded apically. Legs : relative lengths of tarsomeres from basal to apical: 5.5: 3: 4.5: 4.5: 10.5 in foretarsus, 7.5: 5.5: 5.5: 5.5: 13.5 in midtarsus, 9.5: 6.5: 6.5: 7.5: 16.5 in hindtarsus. [Male] : outer margin of tergite VIII ( Fig. 30 ) nearly truncate, with around 7 macrosetae. Sternite VIII ( Fig. 32 ) with about 5 macrosetae and around 10 thin macrosetae; posterior margin strongly pointed with rounded apex. Median lobe of aedeagus ( Figs. 34–35 ) elongated and slightly narrowing toward apex in lateral view ( Fig. 34 ), subparallel sided in ventral view ( Fig. 35 ); a pair of subapico-ventral projections gently curved in lateral view ( Fig. 34 ); basal swelling of aedeagus, circularly pointed in lateral view ( Fig. 34 ); apical lobe short and abruptly narrowing toward apex in ventral view ( Figs. 35–36 ); flagellum clearly shorter than the whole length of median lobe ( Figs. 34–35 ). [ Female ]: tergite VIII ( Fig. 31 ) with moderately rounded margin, with around 7 macrosetae. Sternite VIII ( Fig. 33 ) with about 7 macrosetae; posterior margin slightly pointed. Spermatheca ( Fig. 37 ): entirely thick; spermathecal head about two to three times longer than apical portion of spermathecal stem; spermathecal neck shorter than (sh); basal portion of spermathecal stem short, slightly narrowing toward base, lacking any bent around middle and base; lack of sclerotized portion of spermathecal stem; each part of spermatheca entirely and moderately sclerotized except for membraneous portion of spermathecal duct (sm); (sm) moderate in length. Measurements (male: n=10) : BL, 3.28–4.96 (4.11±0.58); FBL, 1.57–2.35 (1.92±0.23); HL, 0.44–0.66 (0.55±0.08); HW, 0.52–0.71 (0.62±0.06); AL, 0.95–1.23 (1.13±0.09); PL, 0.56–0.78 (0.68±0.07); PW, 0.71–1.00 (0.86±0.09); EL, 0.57–0.84 (0.67±0.08); EW, 0.93–1.27 (1.11±0.12); HTL, 0.53–0.75 (0.63±0.07). Measurements (female: n=10) : BL, 3.25–4.63 (4.18±0.49); FBL, 1.64–2.15 (1.92±0.16); HL, 0.42–0.65 (0.57±0.07); HW, 0.56–0.71 (0.64±0.05); AL, 0.92–1.26 (1.10±0.10); PL, 0.60–0.80 (0.70±0.06); PW, 0.75–0.99 (0.85±0.07); EL, 0.56–0.85 (0.70±0.09); EW, 0.96–1.22 (1.12±0.09); HTL, 0.54–0.72 (0.63±0.06). Distribution. [ JAPAN ]: Hokkaidô, Honshû, Shikoku, Kyûshû, northern Ryûkyû, Okushiri-tô, Sadoga-shima, Awaji-shima, Tanega-shima. See, Fig. 102 . Other localities in literature. [ SOUTH KOREA ]: Gangwon (Kangwon) Province, Chungnam Province, Gyeongnam Province, Jeonnam Province, Jeju Province ( Ahn et al ., 2000 ; Park & Ahn, 2004 ; both as “ A. puetzi ”; re-examinations are needed). Diagnosis. This new species is similar to the other species, especially A. fucicola and A. puetzi , also in male genitalia. We found several distinguishable character states from other Emplenota species below: varying from medium to relatively large size (not very small or very large); entire body pubescent with weak but dense punctures on dorsal surface of head, pronotum and elytra ( Fig. 5 ); impunctured area along midline of head longitudinally and prominently swollen above, forming carina, but other areas flattened compared to A. fucicola ; antennae relatively thick and robust, with short barrel or spherical shape of segment IV; mesoventrite with quite short carina, about 0.27 times as long as mesoventrite; inter coxal cavity of mesoventrite sharply pointed. [ Male ]: sternite VIII ( Fig. 32 ) strongly pointed with rounded apex; subapico-ventral projections on median lobe gently rounded in lateral view ( Fig. 34 ); median lobe subpararell sided in ventral view ( Fig. 35 ); apex of median lobe short in lateral view ( Fig. 34 ); apical lobe isosceles shape, but narrowing abruptly at base in ventral aspect ( Figs. 35–36 ): basal portion of median lobe pointed oblongly, towards to ventral margin of median lobe in lateral aspect ( Fig. 34 ). [ Female ]: spermatheca ( Fig. 37 ) quite thick and wide, without erect and sclerotized stem (ss). Etymology. The species is named after the Latin adjective segregatus meaning separated. Because of the close similarity of the external appearances among A. segregata , A. fucicola , and A. puetzi , some researchers have often confused these taxa (e.g., Ahn et al ., 2000 ; Park & Ahn, 2004 ). Remarks. This new species is very similar to Aleochara ( Emplenota ) fucicola and A . ( E .) puetzi in general appearance. Therefore, the species has generated some problems regarding the taxonomy of Emplenota species occurring in adjacent regions of Japan (see, remarks for A. fucicola and A. puetzi ). Carina like longitudinal elevation on the dorsal surface of the head characterises this species in morphology, but observation under a microscope is needed to confirm the character state. The species has a wide-ranging distribution in Japan , from the northern (Hokkaidô) to the southern islands (Tanega-shima, northern Ryûkyû). In addition, this species may be the most common Emplenota species in Japan , because large numbers of specimens have been collected by many researchers. Previous records of the Asian Emplenota specimens need to be reexamined to be confirmed, especially those recorded from China and the Korean peninsula.