Japanese Journal of Systematic Entomology, 26 (1): 183–189. June 30, 2020.

A New Apterous Rove , Lathrobium hibagon (Coleoptera: Staphylinidae: ), from Western Honshu, Japan

Yoshihiro SENDA c/o Hiwa Museum of Natural Science, Hiwa 1119–1, Hiwa, Shôbara City, Hiroshima, 727–0301 Japan. E-mail: [email protected]

Abstract A new apterous paederine species, Lathrobium hibagon sp. nov. is described from mountainous area of Chûgoku Re- gion, western Honshu, Japan. Detail illustrations of male and female genital parts are given. The structures of endophallus in a fully everted condition is observed and described.

Introduction The verbatim label data indicated by double quotation marks (“”) are given for the holotype and the line breaks of The Lathrobium Gravenhorst, 1802 is distributed the label are indicated by a slash (/). in the Palaearctic, Oriental, Australian, Nearctic, Neotropical, The abbreviations for measurements are follow: AL and Afrotropical Regions, and includes over 750 species – antennal length; BL – body length (approximate whole (Newton, 2019). The species-diversity of this genus is rich length); EL – elytral maximum length; EW – elytral maximum in the Japanese Archipelago, and of these 131 species are width; FBL – forebody length (HL + PL + EL); HL – head divided into seven species groups mainly based on secondary length (apex of clypeus to posterior margin of head capsule); sexual character of male (Shibata et al., 2013; Ryvkin, 2014; HW – head maximum width; PL – pronotal maximum length; Assing, 2019). One of them, the brachypterum group (sensu PW – pronotal maximum width. Watanabe, 1997, 2006) consists of 32 species (Shibata et al., 2013; Watanabe, 2014, 2016; Assing, 2013, 2015, 2019; see Appendix 2), and the members of this group are generally found from organic surface layer in forest. In Chûgoku Region, The Lathrobium brachypterum group only one species, L. okiense Watanabe & Shimada, 2004, was (sensu Watanabe, 1997, 2006) discovered from Oki Islands located off the northern coast of Shimane Prefecture (Watanabe & Shimada, 2004, 2005), but Diagnosis. Body rather small to medium in size for no species have been found from mainland of the region. Lathrobium species (BL approximately 6.0–9.0 mm). Color In this paper, I describe a new species of the brachypterum almost black to blackish brown in body, but often dark reddish species-group from mainland of Chûgoku Region, western brown in sutural and apical area of elytra. Elytra short; hind Japan, with observation of the endophallic structure. wing completely absent. Male abdominal ventrite VIII with shallow depression in middle area, and truncate or slightly Material and Methods emarginated at caudal margin. Comment. The brachypterum group is proposed by This study based on dried specimens mainly collected by Watanabe (1997). Subsequently, it is identified by the above the author and colleagues, and the specimens are preserved characteristics, referring to Watanabe (2006, 2010a). This in the following public and private collections: Ehime study has tentatively followed the classification of species University Museum, Matsuyama (EUMJ), Hiwa Museum of group proposed by the previous study, but it is presumed Natural Science, Shôbara (HIWA), Mr. Keita Kuroda’s private that the present classification of species group is needed to collection (pcKK), and author’s private collection (pcYS). be reviewed with Chinese and Far Eastern Russian species The observational methodology was mainly followed Hanley especially. & Ashe (2003) and Maruyama (2006), but female terminalia were soaked in 5% KOH solution during 8–10 hours under Lathrobium hibagon sp. nov. the room temperature. The endophallus of male genitalia was observed as following methods (ref. Sugaya & Yamasako, Type series. Holotype (HIWA): ♂, “広島県庄原市西城町 2014; Yoshitomi, 2014): 1) The aedeagus removed from body 比婆山御陵 / [JAPAN; Honshu] / Goryô, Mt. Hiba-yama (alt. by the tweezers and sharp needle was soaked in warm 10% 1,200 m) / Saijô-cho, Shôbara-shi / Hiroshima, 20–VII–2019 / KOH solution (60°C, 15–20 min.), then cleaned in water; Y. Senda leg. (litter)” [printed on white label], “HOLOTYPE 2) The endophallus was everted by picking and extracting / Lathrobium hibagon sp. nov. / Det. Y. Senda, 2019” [printed the endophallic sclerites (as copulatory tube) from apex of on red label with black border]. Paratype: JAPAN. Honshu: aedeagus with tweezers in the water, and inflated using water [Hiroshima Pref.] 5♂♂, 2♀♀ (HIWA, EUMJ, pcYS), same through an injector with a fine needle; 3) After observation, data as holotype; 1♀ (HIWA), ditto except 9.VI.2019; 1♂, the aedeagus was preserved in a microvial with pure glycerin, 4♀♀ (pcYS), Mt. Tate-eboshi-yama (alt. 1,200 m), Saijô-cho, which was attached under pinned specimen. Terminology was Shôbara-shi, 23.VI.2019, Y. Senda leg. (collected from litter); mainly followed Naomi et al. (2017), but adopt Frisch (2016) 10♂♂, 7♀♀ (pcYS), ditto except 20.VII.2019; 3♂♂, 1♀ and Watanabe (2016) in part of genital organs. (HIWA), ditto except 16.X.2019; 1♂ (HIWA), Rokunohara,

Ⓒ Japanese Society of Systematic Entomology 184 Senda, Y.

Fig. 1. Lathrobium hibagon sp. nov. –––– A & B, Male, holotype; C & D, male paratype. –––– A, Habitus, dorsal view; B, secondary sexual characters of abdominal ventrites; C, endophallus (inverted) of male genitalia, lateral view; D, ditto, dorsal view. Scale bars = 2.0 mm for A & B; 0.2 mm for C & D.

Yuki, Saijô-cho, Shôbara-shi, 30.V.2019, Y. Akiyama leg.; 1♀ about apical 1/4, dilated to widest point, thence strongly (HIWA), Mt. Iratani-yama, Saijô-cho, Shôbara-shi, 22.V.2019, contracted toward apex; antennomere II constricted at the Y. Akiyama leg. (HIWA). base; antennomeres III and IV more or less cylindrical; Description. Coloration: Body black, shining; antennae, antennomere V–X almost moniliform; antennomere XI mandibles, labrum, basisternum, meso- and metavantrite fusiform, pointed at apex; the ratio of length / width of each reddish brown; labial palpi, maxillae and legs brownish yellow; antennomere as follow: 2.3, 1.4, 1.5, 1.4, 1.3, 1.3, 1.4, 1.3, elytra sometimes dark reddish brown in sutural and apical area. 1.3, 1.3, 2.0; relative lengths of antennomeres: 23.9 : 11.5 : Male. Body elongate, subparallel-sided, slightly flattened 11.6 : 10.7 : 10.3 : 10.6 : 10.6 : 10.5 : 10.0 : 10.7 : 15.5, and dorsally. Head subtrapezoidal in dorsal view, lateral sides relative widths: 13.7 : 10.3 : 10.1 : 10.0 : 10.1 : 10.4 : 10.0 gently arcuate, widest at basal 1/3 of posterior part of : 10.7 : 10.3 : 10.4 : 10.0. Pronotum oblong, widest about eyes; surface with coarsely and setiferously punctures and middle, sides almost straight, feebly contracted from basal coriaceous microsculpture; punctures of surface becoming 1/3 to posterior corner; disk sparsely covered with coarsely closer and less coarse in temporal area. Eyes small, flat. punctures except median smooth area; anterior margin Antennae moderate in length; antennomere I widest weakly emarginate or truncate at middle, obtusely rounded at

June 30, 2020, JJSE 26 (1) Lathrobium hibagon sp. nov. from western Honshu, Japan 185

Fig. 2. Male (A–C) and female (D–F) terminalia of Lathrobium hibagon sp. nov. –––– A, Aedeagus in dorsal view, B, ditto, lateral view; C, ditto, ventral view; D, terga IX (left half) and X; E, gonocoxites; F, apicolateral process of tergum IX, lateral view. Scale bars = 0.5 mm for A–E; 0.2 mm for F. corners; posterior margin almost straight, narrowly rounded Abdomen covered with minute punctures, densely clothed at corners. Scutellar shield impunctate. Elytra widest just with brownish pubescence; ventrite VI (Fig. 1B) normally before posterior corner, expanded weak arcuately from base shape, without secondary sexual character; ventrite VII to posterior corner; disk closely covered with shallowly (Fig. 1B) with a very shallow semielliptical depression punctures, sparsely clothed with fine brownish pubescence. in posteromedial area, feebly and broadly emarginated at Hind wing absent. Basisternum asetose; inner coxal process caudal margin; tergum VIII weakly arcuate at caudal margin; very short, pointed at apex. Mesoventrite asetose, with ventrite VIII (Fig. 1B) with a shallow depression in posterior microsculpture, fully carinate along midline; inner coxal 2/3 of middle area, which densely clothed with short black process very short, pointed at apex. Metaventrite pubescent, setae, more or less emarginated at caudal margin; tergum IX with microsculpture; inner coxal process absence. Legs setigerous except basal 1/5, with posterolateral projections as simple, rather slender, clothed with golden pubescence. long as 1/4 of tergum IX and curved dorsally from apical 1/3

June 30, 2020, JJSE 26 (1) 186 Senda, Y. to pointed apex; ventrite IX elongate, widest at basal corner, Etymology. The specific name of this new species narrowed apically, setigerous in apical half, with caudal is derived from ”Hibagon”, which is a kind of Japanese margin feebly arcuate; tergum X trapezium, widest at basal mysterious (or cryptid) likely North American Bigfoot corner with some macrosetae and pores, with caudal margin or Himalayan Yeti. Sightings have been mainly reported in the arcuate. Aedeagus (Fig. 2A–C) robust, weakly asymmetric, 1970s around the Mt. Hiba-yama area, the type locality of this well sclerotized except membranous ventral side; median lobe new species. The specific name is given to this species with robust, nearly parallel-sided, broadly rounded at apex; ventral the hope of preserving the good natural environment in which sclerite slender, with a long median carina ventrally, widest Hibagon can ever live. at apical 1/5, weakly curved ventrally at 1/2, dilated to widest Diagnosis. This new species is similar to Lathrobium point, thence emarginately contracted toward saliently round kagawaense Watanabe, 2016 in general appearance and basal apex in ventral view, with a small hook in apex; paramere conformation of male genital organ, but distinguishable considerably larger than median lobe, curved dorsally from from it by the following characteristics: 1) ventral sclerite 1/2 to apex, almost parallel sided in basal half, contracted of aedeagus comparatively slender, weakly curved ventrally, toward very acute apex in dorsal view; internal sac (Fig. 1C & with rounded apex (comparatively wide, not curved ventrally, D) shorter than ventral sclerite, simple, symmetrical, without with pointed apex in L. kagawaense); 2) paramere distinctly any projection in everted condition, partly covered with small curved dorsally from 1/2 to apex (curved dorsally at about 1/2 spicules in dorso-lateral area of basal 2/3, without any other in L. kagawaense); 3) copulatory tube slender (rather robust in sclerites; copulatory tube (Fig. 1C & D) well sclerotized, L. kagawaense). short, slender, tapering to pointed apex. Female. Similar to male in general appearance. The ratio of Discussion length / width of each antennomere from 1st to 11th as follow: The endophallus of the genus Lathrobium have not been 2.4, 1.4, 1.3, 1.3, 1.4, 1.2, 1.2, 1.1, 1.2, 1.2, 1.8; relative observed and studied in detail. Watanabe (2016) did not lengths of antennomere from basal to apical: 27.1 : 11.8 : 11.8 describe any internal structures of aedeagus. Peng et al. (2014) : 11.5 : 12.1 : 10.6 : 10.0 : 10.0 : 10.3 : 10.9 : 15.3, and relative and Assing (2015) described and observed the endophallus widths: 13.6 : 10.0 : 10.7 : 11.1 : 10.4 : 10.4 : 10.0 : 10.7 : 10.7 through the aedeagus, and they probably referred to copulatory : 10.7 : 10.4. Tergum VIII weakly emarginate at caudal margin; tube as “sclerotized spines” (Peng et al., 2014) or “sclerotized ventrite VIII clearly projected apically, arcuate at caudal structures” (Assing, 2015). In this paper the endophallus of margin; tergum IX (Figs. 2D & E) setigerous except basal 1/3, L. hibagon sp. nov. fully inflated condition is described, and with posterolateral projections as long as 1/4 of tergum IX and consists of copulatory tube and small spicules in basal 2/3 of curved dorsally from apical 1/3 to pointed apex; tergum X (Fig. internal sac. Based on my preliminary observation of several 2D) small, subquadrate, shorter than posterolateral projections species of this genus, detail of the endophallus is different of tergum IX, with a few macrosetae in apical half of middle between species groups. Further studies of the endophallus of area, with caudal margin weakly emarginated. Gonocoxites as this genus in species or species group level will be expected. shown in Fig. 2E: lateral gonocoxal plate (distal and proximal For close and precise examination of the endophallus, it is gonocoxites fused) elongate, with a few setae in apical area, necessary to evert the internal sac from the aedeagal apex. with apical margin weakly arcuate. As a result of comparing female of present new species Measurements. Male (n = 7) –– BL: 6.92–7.67 mm with several species included other species groups (see (7.29±0.32 mm); FBL: 2.90–3.27 mm (3.09±0.13 mm); Appendix 1), new species distinguishable from the others by HL: 0.82–1.00 mm (0.90±0.06 mm); HW: 0.88–1.01 mm combination of following features: 1) posterolateral projections (0.94±0.05 mm); AL: 1.58–1.77 mm (1.71±0.06 mm); PL: of tergite IX comparatively short, with feebly convex and slim 1.15–1.31 mm (1.23±0.06 mm); PW: 0.94–1.09 mm (1.01±0.05 in basal part; 2) tergite X more or less wide, rather small; 3) mm); EL: 0.88–1.00 mm (0.95±0.04 mm); EW: 1.02–1.14 mm lateral gonocoxal plate comparatively slim, elongate. These (1.10±0.05 mm). HL/HW = 0.91–1.00 (0.97±0.03); AL/FBL = features appear to be similar for L. kagawaense Watanabe, L. 0.54–0.58 (0.55±0.01); PL/PW = 1.18–1.31 (1.21±0.05); PW/ toonicum Assing (present study), and L. trabale Assing (fig. 142 HW = 1.02–1.14 (1.08±0.04); EL/EW = 0.80–0.93 (0.87±0.04); in Assing, 2015). The present classification of species group in EW/PW = 1.04–1.13 (1.09±0.03). Japanese Lathrobium is mainly based on male secondary sexual Female (n = 3) –– BL: 7.06–7.16 mm (7.13±0.06 mm); characters, and female ones have not yet examined and used FBL: 2.91–3.04 mm (2.95±0.08 mm); HL: 0.87–0.92 mm adequately. (0.89±0.03 mm); HW: 0.85–0.91 mm (0.87±0.03 mm); AL: The observations in this study suggest that male 1.57–1.64 mm (1.60±0.04 mm); PL: 1.14–1.20 mm (1.17±0.03 endophallus and female sexual characters are useful for the mm); PW: 0.96–0.98 mm (0.97±0.01 mm); EL: 0.88–0.92 mm classification of species groups. Actually, characters of four (0.9±0.02 mm); EW: 1.04–1.13 mm (1.07±0.05 mm). HL/HW Chinese species groups proposed by Assing (2015) include = 0.96–1.08 (1.02±0.06); AL/FBL = 0.54–0.55 (0.54±0.00); male endophallus and female sexual characters. The present PL/PW = 1.19–1.22 (1.21±0.02); PW/HW = 1.05–1.15 classification of species groups probably should be revised (1.11±0.05); EL/EW = 0.81–0.87 (0.84±0.03); EW/PW = observing these characters. However, it is unclear whether the 1.08–1.15 (1.11±0.04). above features are common within the species group. This is a Distribution. Western Honshu (northeastern area of problem for future studies. Hiroshima Prefecture).

June 30, 2020, JJSE 26 (1) Lathrobium hibagon sp. nov. from western Honshu, Japan 187

Acknowledgements Peng, Z., L.-Z. Li & M.-J. Zhao, 2014. Seventeen new species and additional records of Lathrobium (Coleoptera, Staphylinidae) I gratefully acknowledge the kind help of Dr. Yasuaki from mainland China. Zootaxa, 3780 (1): 1–35. Watanabe (Machida City) for his kind guidance and providing Ryvkin, A. B., 2014. Notes on distribution and taxonomy of some important his paper. I would like to express my hearty thanks Far Eastern Staphylinidae (Coleoptera). Acta Biologica to Dr. Hiroyuki Yoshitomi (EUMJ) for reviewing the draft Universitatis Daugavpiliensis, 14: 177–185. of this paper and his kind helps in various ways, to Mr. Shibata, Y., M. Maruyama, H. Hoshina, T. Kishimoto, S.-I. Naomi, S. Nomura, V. Puthz, T. Shimada, Y. Watanabe & Yoshifumi Akiyama (HIWA) and Ms. Ai Katô (Kurashiki S. Yamamoto, 2013. Catalogue of Japanese Staphylinidae City) for their kind support of field survey, and to Mr. Shôma (Insecta: Coleoptera). Bulletin of the Kyushu University Sejima (Kashiwa City), Mr. Ryôtarô Wakimura (Aioi High Museum, (11): 69–218. School of Hyôgo), and Mr. Keita Kuroda (Laboratory of Sugaya, K. & J. Yamasako, 2014. A new species of the genus Environmental Entomology, Ehime University) for their kind Ishikawatrechus (Coleoptera, Trechinae) from Japan. Zootaxa, offer of specimens for this study. I also thank to the Northern 3768 (2): 189–195. Area Branch Office of Hiroshima Prefectural Government Watanabe, Y., 1997. Four new species of the Lathrobium and Shobara City Board of Education for their permission brachypterum group (Coleoptera, Staphylinidae) from the Hokuriku District, Japan. Elytra, Tokyo, 25: 135–146. for my survey in the nature reserve area. Last, but not least, Watanabe, Y., 1998. Five new species of the Lathrobium (s. str.) I am greatly indebted to late Mr. Narumi Kanazawa (Retired nomurai group (Coleoptera, Staphylinidae) from Japan. President of the Hiba Society of Natural History) who had Elytra, Tokyo, 26: 85–98. kindly guided, supported, and encouraged to my study of the Watanabe, Y., 2001. Four new species of apterous Lathrobium natural history in the northeastern area of Hiroshima Prefecture. (Coleoptera, Staphylinidae) from Central Honshu, Japan. Part of this study was conducted as “Entomological Elytra, Tokyo, 29: 465–475. Survey of Hiba Mountains” by HIWA. Watanabe, Y., 2005a. Apterous Lathrobium (Coleoptera, Staphylinidae) from the Kii Peninsula in Japan. 1 Group of Lathrobium shingon. Elytra, Tokyo, 33: 313−325. References Watanabe, Y., 2005b. Apterous Lathrobium (Coleoptera, Assing V., 2013. On the Lathrobium fauna of Japan (Coleoptera: Staphylinidae) from the Kii Peninsula in Japan. 2 Group of Staphylinidae: Paederinae). Linzer Biologische Beiträge, 45: Lathrobium pollens. Elytra, Tokyo, 33: 589−601. 1615–1641. Watanabe, Y., 2006. Apterous Lathrobium (Coleoptera,Staphylinidae) Assing, V., 2015. New species and additional records of from the Kii Peninsula in Japan. 3 Group of Lathrobium Lathrobium and Elytrobium from the Palaearctic region, with brachypterum. Elytra, Tokyo, 34: 47–62. special reference to the fauna of East Yunnan (Coleoptera: Watanabe, Y., 2010a. Lathrobium brachypterum and its new Staphylinidae: Paederinae). Beiträge zur Entomologie, 65: relative (Coleoptera, Staphylinidae) from Central Honshu, 41–74. Japan. Elytra, Tokyo, N. Ser., 38: 257–265. Assing, V., 2019. New species and records of Lathrobium, with Watanabe, Y., 2010b. More new species of the group of Lathrobium the first and southernmost record of the genus from Vietnam nomurai (Coleoptera, Staphylinidae) from Eastern Shikoku, (Coleoptera: Staphylinidae: Paederinae). Acta Musei Japan. Japanese Journal of Systematic Entomology, 16: 63−69. Moraviae, Scientiae biologicae, 104 (2): 87–107. Watanabe, Y., 2014. New brachypterous Lathrobium (Coleoptera, Frisch, J., 2016. On the Scopaeina Mulsant & Rey of Australasia Staphylinidae) from the Island of Awaji-shima in Hyôgo (Staphylinidae, Paederinae): type revisions and new Prefecture, Japan. Elytra, Tokyo, N. Ser. 4: 133−140. biogeographic data. Soil Organisms, 88: 55–88. Watanabe, Y., 2016. Four new brachypterous Lathrobium Hanley, R. S. & J. S. Ashe, 2003. Techniques for dissecting adult (Coleoptera, Staphylinidae) from Eastern Shikoku, Japan. aleocharine (Coleoptera: Staphylinidae). Bulletin of Elytra, Tokyo, N. Ser., 6: 321−330. Entomological Research, 93: 11–18. Watanabe Y. & Shimada T. 2004. A new apterous Lathrobium Maruyama, M., 2006. Revision of the Palearctic species of (Coleoptera, Staphylinidae) from the Island of Dôgo of the myrmecophilous genus Pella (Coleoptera, Staphylinidae, Oki Islands off western Honshu, Japan. Elytra, Tokyo, 32: Aleocharinae). National Science Museum Monographs, (32): 293−298. 1–207. Watanabe Y. & Shimada T. 2005. More apterous Lathrobium Naomi, S.-I., S. Nomura & V. Puthz, 2017. The subfamily Steninae (Coleoptera, Staphylinidae) from Nishi-no-shima of the Dôzen Macleay, 1825 (Coleoptera: Staphylinidae) of Japan Part 1. group of the Oki Islands off western Honshu, Japan. Elytra, Dianous and Stenus (S. comma group to S. guttalis group). Tokyo, 33: 603–608. National Museum of Nature and Science Monographs, (46): Yoshitomi, H., 2014. Comparative morphology of the endophallic 1–339. structures of the genus Laius (Coleoptera, Melyridae), with Newton, A.F., 2019. StaphBase: Staphyliniformia world catalog the descriptions of three new species. European Journal of database (version Nov 2018). In: Species 2000 & ITIS Taxonomy, 97: 1–29. Catalogue of Life, 2019 Annual Checklist. Website at https:// www.catalogueoflife.org/col/details/database/id/204 [accessed [Received: May 5, 2020; accepted: June 4, 2020] 30. Dec. 2019].

June 30, 2020, JJSE 26 (1) 188 Senda, Y.

Appendix 1: Comparative materials examined Pref.] 3♂♂, 4♀♀ (pcYS), Mt. Yamanori-yama (alt. 600 m), Maniwa-shi, 29.IV.2019, Y. Senda leg. The Lathrobium brachypterum Sharp, 1889 group (sensu Watanabe, 1997, 2006) The Lathrobium pollens Sharp, 1889 group (sensu Watanabe, 2005b) Lathrobium kagawaense Watanabe, 2016 Specimens examined. JAPAN. Shikoku: [Kagawa Pref.] Lathrobium pollens Sharp, 1889 2♂♂, 1♀ (pcYS), Mt. Daisen-zan (alt. 1,000 m), Mannô-cho, Specimens examined. JAPAN. Honshu: [Tokyo Pref.] 29.VII.2007, Y. Senda leg. 2♂♂ (pcYS), Mt. Tsukiyomi-yama (alt. 1, 020 m), Okutama- cho, 28.IV.2018, S. Sejima leg. Lathrobium toonicum Assing, 2019 Specimens examined. JAPAN. Shikoku: [Ehime Pref.] Lathrobium omogoense Watanabe, 1991 3♂♂, 2♀♀ (pcYS), Mt. Saragamine, Tôon-shi, 5.VII.2009, Y. Specimens examined. JAPAN. Shikoku: [Ehime Pref.] Senda leg. 1♂ (EUMJ), Val. Omogo-kei, Omogo-mura, 12.XI.1996, M. Mino leg. The Lathrobium ishiharai Hayashi, 1994 group (sensu Ryvkin, 2014) Lathrobium tokushimanum Watanabe & Yoshida, 2009 Specimens examined. JAPAN. Shikoku: [Tokushima Pref.] Lathrobium ishiharai Hayashi, 1994 1♂ (pcKK), Dosu-tôge, Kamibun, Kamiyama-cho, 3.XII.2017, Specimens examined. JAPAN. Honshu: [Hiroshima K. Kuroda leg. Pref.] 1♀ (HIWA), Kan’on-shinmachi, Naka-ku, Hiroshima- shi, 5.X.1998, S. Nakamura leg.; 1♂ (HIWA), Imaida (alt. Lathrobium sp. 35 m), Kabe-chô, Asakita-ku, Hiroshima-shi, 24.VI.1999, Specimens examined. JAPAN. Honshu: [Nagano Pref.] S. Nakamura leg.; 1♂ (HIWA), Higashihara (alt. 5 m), 3♂♂, 2♀♀ (pcYS), Koshimizugahara (alt. 1,240 m), Asaminami-ku, Hiroshima-shi, 14.VII.1998, S. Nakamura Togakushi, Nagano-shi, 3.VI.2018, S. Sejima leg. leg.; 1♀ (HIWA), ditto except Yagi (alt. 12 m), 24.IV.1999; Notes. This species is similar to Lathrobium loebli 1♂ (HIWA), Minamihatajiki-machi, Miyoshi-shi, 21.VI.1999, Assing, 2013 in general appearance and basal conformation S. Nakamura leg.; 1♀ (HIWA), Mihara-machi, Miyoshi-shi, of male genital organ, but is different from the latter by the 25.IV.1999, S. Nakamura leg.; 1♀ (HIWA), Yoshida, Yoshida- slimmer apical lobe of aedeagal median lobe. I will leave the cho, 24.IV.1999, S. Nakamura leg.; 1♂, Shimodoi (alt. 244 taxonomic aspects of this species to future research. m), Doi, Togôchi-cho, 26.IV.1999, S. Nakamura leg. Shikoku: [Ehime Pref.] 1♀ (EUMJ), Nakamura, Ôzu-shi, 7.X.2001, S. The Lathrobium tahirai group Ito & Y. Nakata leg. (sensu Watanabe, 2001)

The Lathrobium nomurai Nakane, 1955 group Lathrobium nidoagense Watanabe, 2001 (sensu Watanabe, 1998, 2010b) Specimens examined. JAPAN. Honshu: [Gunma Pref.] 2♂♂, 1♀ (pcYS), Kusatsu (alt. 1,270 m), Kusatsu-machi, Lathrobium aioiense Watanabe, 2002 3.VI.2018, S. Sejima leg. Specimens examined. JAPAN. Honshu: [Hyôgo Pref.] . 1♂, 5♀♀ (pcYS), Kuga (34°50'02"N, 134°28'37"E), Aioi-shi, 27.III–24.V.2019, R. Wakimura leg. Note. All specimens were collected by the trap set in subterranean zone.

Lathrobium kamezawai Watanabe, 2002 Specimens examined. JAPAN. Shikoku: [Ehime Pref.] 1♀ (pcYS), Mt. Saragamine, Tôon-shi, 5.VII.2009, Y. Senda leg.

The Lathrobium shingon Watanabe, 1992 group (sensu Watanabe, 2005a)

Lathrobium taishakuense Watanabe, 2011 Specimens examined. JAPAN. Honshu: [Hiroshima Pref.] 11♂♂, 7♀♀ (pcYS), Val. Taishaku-kyô (alt. 370 m), Misaka, Tôjô-cho, Shôbara-shi, 16.VI.2019, Y. Senda leg.

Lathrobium suzukii Watanabe, 2011 Specimens examined. JAPAN. Honshu: [Okayama

June 30, 2020, JJSE 26 (1) Lathrobium hibagon sp. nov. from western Honshu, Japan 189

Lathrobium sugiei Watanabe, 1997 Appendix 2: List of Japanese species of Lathrobium Honshu (Hokuriku Region: Ishikawa). brachypterum group Lathrobium tamotsui Watanabe, 1994 Shikoku (Ehime). Lathrobium tokuenjiense Watanabe, 2016 Lathrobium adachii Watanabe, 2010 Shikoku (Tokushima). Honshu (Kantô Region: Saitama; Tokyo; Kanagawa; Lathrobium toonicum Assing, 2019 Shizuoka) Shikoku (Ehime). Lathrobium brachypterum Sharp, 1889 Lathrobium trabale Assing, 2015 Honshu (Kantô Region: Kanagawa; Yamanashi; Honshu (Kinki Region: Kyoto). Shizuoka). Lathrobium wasamatanum Watanabe, 2006 Lathrobium hibagon sp. nov. Honshu (Kii Peninsula: Nara). Honshu (Chûgoku Region: Hiroshima).

Lathrobium horridum Assing, 2013 Kyushu (Fukuoka) Lathrobium isense Watanabe, 2006 Honshu (Kii Peninsula: Mie). Lathrobium kagaense Watanabe & Hoshina, 2003 Honshu (Hokuriku Region: Ishikawa). Lathrobium kagawaense Watanabe, 2016 Shikoku (Kagawa). Lathrobium kasaharai Watanabe, 2002 Honshu (Kantô Region: Chiba). Lathrobium kinokuniense Watanabe, 2006 Honshu (Kii Peninsula: Wakayama). Lathrobium kitosonense Watanabe, 2016 Shikoku (Tokushima). Lathrobium kotsuzanum Watanabe, 2016 Shikoku (Tokushima). Lathrobium koyasanum Watanabe, 2006 Honshu (Kii Peninsula: Wakayama). Lathrobium kuramaicum Assing, 2013 Honshu (Kinki Region: Kyoto). Lathrobium kurosawai Watanabe, 2001 Eastern Honshu (Fukushima; Tochigi; Gunma; Toyama; Gifu). Lathrobium masaoi Watanabe, 1999 Honshu (Kii Peninsula: Mie; Nara). Lathrobium masarui Watanabe, 2014 Awaji-shima Lathrobium masumotoi Watanabe, 2011 Honshu (Chûbu Region: Nagano). Lathrobium monticola Sharp, 1889 Kyushu (Nagasaki). Lathrobium nabetaniense Watanabe, 1997 Honshu (Hokuriku Region: Ishikawa). Lathrobium nankiense Watanabe, 2006 Honshu (Kii Peninsula: Mie; Wakayama). Lathrobium notoense Watanabe, 1997 Honshu (Hokuriku Region: Ishikawa). Lathrobium ohtohense Watanabe, 2006 Honshu (Kii Peninsula: Wakayama). Lathrobium okiense Watanabe & Shimada, 2004 Oki Islands. Lathrobium sasajii Watanabe, 2001 Honshu (Hokuriku Region: Ishikawa; Fukui). Lathrobium satoi Watanabe, 2003 Honshu (Tôkai Region: Aichi). Lathrobium shinanense Watanabe, 2011 Honshu (Chûbu Region: Nagano). Lathrobium shiritakanum Watanabe, 1997 Honshu (Hokuriku Region: Ishikawa).

June 30, 2020, JJSE 26 (1)