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Taxonomy of Homoeusa Kraatz, 1856 (Coleoptera, Staphylinidae) from te East Palearctic: I. Homoeusa rufescens (Sharp, 1874) and a new allied species
‡ Kyushu University, Fukuoka, Japan
§ Te Kyushu University Museum, Fukuoka, Japan
Corresponding author: Tsubasa Nozaki ( dosanko.lathrobium@gmail.com )
© 2022 Tsubasa Nozaki, Munetoshi Maruyama.
This is an open access article distributed under te terms of te Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided te original author and source are credited.
There is insufficient information to identify most species of te myrmecophilous rove beetle genus Homoeusa. In this paper, after examining te type material, Homoeusa rufescens (Sharp, 1874) is redescribed in detail and its new allied species Homoeusa ovata sp. nov. is described. We also observed te behavior of these two species in te field; te behavior was similar to that reported for H. acuminata (Märkel, 1842). A checklist of Homoeusa from te Palearctic and Nearctic is also provided.
Aleocharinae, description, Dinardina, Homoeusa ovata sp. nov., Lasius, myrmecophily, new species, rove beetle
Nine species of te myrmecophilous genus Homoeusa Kraatz, 1856 (tribe Oxypodini) are known from te Palearctic region, of which eight are recorded from te East Palearctic, i.e., China, Taiwan, Far East Russia, and Japan (Smetana 2004; Pace 2010; Maruyama et al. 2013). Most species have not been redescribed since their original descriptions 90–120 years ago, which are very short and almost useless for identification. This series of papers aims to revise te East Palearctic species of Homoeusa.
Homoeusa is distinguishable from te other myrmecophilous oxypodine genera of te Palearctic by its sub-limuloid body shape and unilobed ligula; te latter distinguishes it from te similar genus Thiasophila Kraatz, 1856, which has a bifid ligula. Maruyama and Zerche (2014) suggested that Thiasophila rufescens Sharp, 1874 described from Japan could be a member of Homoeusa. Probably based on this statement, Schülke and Smetana (2015) listed T. rufescens as a Homoeusa species. Here, we confirmed that T. rufescens should be transferred to Homoeusa. We found that another species allied to T. rufescens is included in te syntypes of T. rufescens and is very common in te nests of Lasius species in te fuliginosus group (formerly members of te subgenus Dendrolasius). It was found to be a new species and is also described here. Te taxonomy of Homoeusa is very difficult and some species complexes still require time to work. Therefore, this paper treats these two species, which are very common and need to be identified, prior to te revision of te whole genus. We discuss te feeding behavior of these species and provide a checklist of te world species of Homoeusa.
Te material examined in this study is deposited mostly in te Kyushu University Museum (KUM), and some in Te Hokkaido University Museum, Sapporo (HUM), National Museum of Nature and Science, Tsukuba (NSMT), Sagamihara City Museum, Kanagawa, Japan (SCM), and private collections of Hiromu Kamezawa (Saitama-ken) (cKam). Type material of Homoeusa rufescens is deposited in te Natural History Museum, London (NHM). Part of te paratypes from te Russian Far East are in te Institute of Biology and Soil Science, Vladivostok, Russia (IBSS).
Measurement definitions and abbreviations are shown as follows: BL, approximate body length; AL, antennal length; HW, head width; PL, pronotal length; PW, pronotal width; EL, elytral length (sutural length from apex of scutellum to posterior margin of elytra); EW, elytral width; HTL, hind tibial length. Measurements of dorsal morphology were made on 20 specimens of each species, and then te sexes were identified. Measurements of each segment of te antenna (six specimens of each species) were made on dissected specimens mounted in Euparal.
Symbiotic hosts were mostly identified by MM, F. Ito, and some by TN and K. Kinomura.
Te scientific names of Lasius ants follow Bolton (1995), Radchenko (2005), and Boudinot et al. (2022). Lasius fuji was formerly recognized as te eastern Palearctic population of L. fuliginosus. Recently, te Japanese population of “Lasius fuji” has been suggested to be a species complex (Maruyama et al. 2013). Therefore, ‘Lasius cf. fuliginosus’ is adopted as te name of te Japanese population here. Lasius fuliginosus and allied species have long been classified in te subgenus Dendrolasius. However, Boudinot et al. (2022) synonymized all te subgenera of Lasius with te genus Lasius and recognized five species groups, which is adopted here.
Te species names of symbiotic hosts are abbreviated in “Type material” and “Additional material” as follows: Lasius fuliginosus Group: LFFJ, L. fuji Radchenko, 2005; LFFL, L. fuliginosus (Latreille, 1798); LFcfF, Lasius cf. fuliginosus; LFM, Lasius morisitai Yamauchi, 1979; LFN, L. nipponensis Forel, 1912; LFO, L. orientalis Karawajew, 1912; LFS, L. spathepus Wheeler, 1910; LJ, Lasius japonicus Santschi, 1941 (te niger group).
Te distribution and host ant species of each species in te checklist is a synthesis of information from mostly Schülke and Smetana (2015), Maruyama et al. (2013), and this paper.
Subtribe Dinardina Mulsant & Rey, 1873
Homoeusa Kraatz, 1856: 76 (original description, type species: Euryusa acuminata Märkel, 1842, by monotypy); Kraatz 1857: 16 (diagnosis); Jacquelin du Val 1857: 11 (catalogue); Fenyes 1919: 389 (redescription); Bernhauer and Scheerpeltz 1926: 736 (synonymy, catalogue); Smetana 2004: 467 (catalogue); Schülke and Smetana 2015: 682 (catalogue).
Myrmobiota Casey, 1893: 594 (original description, type species: M. crassicornis Casey, 1893, by monotypy); Fenyes 1919: 392 (redescription); Bernhauer and Scheerpeltz 1926: 736 (catalogue; synonym of Homoeusa); Seevers 1978: 75 (redescribed).
Soliusa Casey, 1900: 53 (original description, type species: S. crinitula Casey, 1900, by monotypy); Fenyes 1919: 389 (synonym of Homoeusa); Bernhauer and Scheerpeltz 1926: 736 (catalogue; synonym of Homoeusa).
This genus is distinguished by te following combination of characteristics: body somewhat sub-limuloid; apex of ligula unilobed and round; antennae not or weekly clubbed; posterior margin of antennal insertion forming distinct latitudinal carina extending medially; spermatheca somewhat S-shaped.
As mentioned in Maruyama (2009), this genus is similar to Losiusa and Aspidobactrus, which are called te “Homoeusa genus complex”. Together with some other genera, these genera are classified in te subtribe Dinardina of te tribe Oxypodini (Schülke and Smetana 2015). Te subtribe Dinardina is defined based on its limuloid body and shield-like pronotum (Seevers 1978). However, te monophyly of Dinardina (sensu Seevers 1978) has been rejected; te Dinarda+Thiasophila clade was distant from Myrmobiota (Osswald et al. 2013), which is a close relative of Homoeusa and often regarded as a junior synonym of Homoeusa. Te Homoeusa genus complex is assumed to form a clade with Myrmobiota distant from Dinarda+Thiasophila given their symbiotic hosts and morphological characteristics of te head, ligula, and facial structure of te body. Te relatedness of te Homoeusa genus complex and Nearctic genus Decusa Casey, 1900 was also suggested (see also Wasmann 1901). To reveal te relationships among these genera in detail, future phylogenetic research is necessary.
Homoeusa rufescens (Sharp, 1874), combination confirmed
Japanese name: Hoso-hirata-ariyadori Figs 1–4, 6–9, 10–16, 28, 29
Thiasophila rufescens Sharp, 1874: 5; Fenyes 1919: 393 (catalogue); Bernhauer and Scheerpeltz 1926: 771 (catalogue); Smetana 2004: 488 (catalogue).
Homoeusa rufescens: Maruyama and Zerche 2014: 17 (mentioning actual generic affiliation); Schüelke and Smetana 2015; 682 (catalogue).
Lectotype (Figs 1–3), here designated, ♂, “Japan. Lewis.” / “Sharp Coll 1905-313” / “Syn-type” (blue round curator label) / “Lectotype Thiasophila rufescens det. Maruyama, 2003” (dissected by MM) (NHM). Paralectotypes, 1 ♀, same data as lectotype but labelled “Type” (red round curator label) / “Thiasophila rufescens type D.S.” (NHM); 5 unsexed, same data as lectotype, but one is labelled “Nagasaki” (NHM).
Japan: Honshû: Fukushima-ken: 1 unsexed, Yukiwari-bashi, Nishigô-mura, 29. VII. 2000, T. Kobayashi. Ibaraki-ken: 2 unsexed, Inohana Pass, 29. V. 1994, Y. Hagino. Tochigi-ken: 1 unsexed, Tobiyama Castle, Utsunomiya-shi, 17–18. VI. 1998, M. Maruyama (LFS); 2 unsexed, 1♀, same locality, 17. VI. 1998, M. Maruyama (LFcfF); 2 unsexed, Shimokomoriya, Utsunomiya-shi, 6. VII. 1999, M. Maruyama; 3 unsexed, Sayado, Môka-shi, 15. VI. 2000, T. Kobayashi & H. Obata; 81 unsexed, Ichikai-machi, Haga-gun, 29. IV.–2. V. 2002, Seidai Nagashima. Gunma-ken: 27 unsexed, Mt. Sakurayama, Onishi-chô, 22. V. 1999, Shiho Arai (LFS); 2 unsexed, Sakurayama Park, Onishi-chô, 18. V. 1998, Shiho Arai (LFS); 26 unsexed, 7♂, 3♀, same locality, 9. V. 1998, Shiho Arai (LJ); 10 unsexed, Sakurayama, Onishi-chô, 9. V. 1998, Koji Toyoda (LFS); 5 unsexed, Nakanojo Forest Park, Nakanojô-machi, 8. VI. 2001, T. Watanabe. Saitama-ken: 15 unsexed, Shioyama, Ranzan-machi, 21. VI. 1996, Koji Toyoda; 10 unsexed, same locality, 8. VI. 1997, Koji Toyoda (LFcfF); 16 unsexed, same locality, 10. V. 1998, K. Toyoda (LFcfF); 3 unsexed, Shôgunsama, Ranzan-machi, 21. IV. 1999, K. Toyoda; 1 unsexed, Sugiyama, Ranzan-machi, 13. VII. 1998, K. Toyoda; 13 unsexed, Toki-gawa, Kamagata-mura, Ranzan-machi, 25. IV. 1999, K. Toyoda; 2 unsexed, Shiro-yama, Kamagata-mura, Ranzan-machi, 17. VI. 2000, K. Toyoda (LFcfF); 4 unsexed, Ranzan-keikoku, Kamagata-mura, Ranzan-machi, 14. V. 2000, K. Toyoda; 2 unsexed, Hashidake, Chichibu-shi, 26. IV. 1998, S. Arai; 2 unsexed, Nakano, Showa-machi, 4. V. 2002, Hiromu Kamezawa (LFS) (cKam); 1 unsexed, same locality, 26. VI. 2001, H. Kamezawa (LFcfF) (cKam); 2 unsexed, same locality, 4. V. 2002, H. Kamezawa (LFcfF) (cKam); 5 unsexed, same locality, 4. V. 2003, H. Kamezawa (LFcfF) (cKam); 1 unsexed, Yokoze-machi, Chichibu-shi, 10–11. V. 1995, Yoshinori Kaneko, Akio Ito, Satoshi Tsuboyama. Chiba-ken: 1 unsexed, Mt. Kiyosumi, Amatsukominato, 9. VI. 1991, T. Takeda; 1 unsexed, Azeta, Sakura-shi, 20. VI. 1998, M. Maruyama (LFS); 1 unsexed, 1♀, same locality, 23–24. VI. 1998, M. Maruyama (LFS); 2 unsexed, same locality, 26. VI. 1998, M. Maruyama (LFS). Tôkyô-to: 1 unsexed, Mt. Takao, 1. V. 1985, S. Nomura; 2 unsexed, same locality, 13. V. 1985, S. Nomura; 2 unsexed, Takao-san (450 m in alt.), Hachioji-shi, 4. VI. 2001, M. Maruyama (LFS); 1 unsexed, Otomeyama Park, Shinjuku-ku, 13. V. 1985, S. Kubota; 3 unsexed, Dokan-bori, Imperial Palace, 17. V. 2000, T. Shimada (NSMT); 34 unsexed, Kami-dokan-bori, Imperial Palace, 17. V. 2000, Shiho Arai (LFcfF) (MSMT). Kanagawa-ken: 2 unsexed, Kawasaki-shi, 1. V. 1985, S. Kubota; 3 unsexed, Ikuta-Ryokuchi, Kawasaki-shi, 13. IV. 2002, K. Matsumoto; 1 unsexed, Mt. Masukata, Kawasaki-shi, 15. VI. 1996, K. Kawada; 1 unsexed, Jinmu-ji, Zushi-shi, 20. VI. 2003, M. Maruyama; 1 unsexed, Mt. Tanzawa, 26. VI. 1983, Y. Hirano; 1 unsexed, Kawana, Fujisawa, 19. VI. 2000, T. Watanabe (LFS); 1 unsexed, same locality, 7. V. 2001, T. Watanabe (LFcfF); 3 unsexed, 1♂, same locality, 14. V. 2001, T. Watanabe; 6 unsexed, Toya, Tsukui, 11. V. 1976, Ryo Kiryu (SCM); 6 unsexed, same locality, 29. IV. 1977, Ryo Kiryu (SCM); 2 unsexed, Mikage, Tsukui, 18. V. 1976, Ryo Kiryu (SCM); 1 unsexed, same locality, 23. IV. 1977, Ryo Kiryu (SCM); 1 unsexed, same locality, 9. VI. 1979, Ryo Kiryu (SCM). Yamanashi-ken: 2 unsexed, Karumizu-rindô, (1400 m in alt.), Narusawa, 29. VI. 2011, T. Watanabe. Shimane-ken: 1 unsexed, Urahikimi, 6. VI. 1988, S. Nomura. Okayama-ken: 1 unsexed, Ono Shine, Kawakami, Ohara-chô, Mimasaka-shi, 7. VI. 2009, Yoshifumi Fuzitani; 5 unsexed, same locality, 5. V. 2009, Yoshifumi Fuzitani (LFS). Yamaguchi-ken: 3 unsexed, Nishimagura, (100 m in alt.), Kusunoki, 30. V.–1. VI. 2000, Toshio Kishimoto. Shikoku: Kagawa-ken: 7 unsexed, 1♂, Usa-Jinja, Nagaona, Sanuki-shi, 31. V. 2001, M. Maruyama (LFS); 11 unsexed, 1♂, 1♀, Ôtaki-san, Shionoe-chô, 2. VI. 2001, M. Maruyama (LFN); 1 unsexed, Fujio-Jinja, Nishiuta-chô, Takamatsu-shi, 31. V. 2001, M. Maruyama (LFS); 4 unsexed, same locality, 1. VI. 2001, M. Maruyama (LFN); 5 unsexed, Furodani, Miki-chô, 30. VII. 2000, K. Izawa; 1 unsexed, Kamiyama, Miki-chô, 1. VI. 2001, M. Maruyama (LFS); 4 unsexed, Ôtawa, Nagano-chô, 22. V. 2000, F. Ito; 11 unsexed, Atago-yama, Kotohira-chô, 1. VI. 2001, M. Maruyama (LFS). Ehime-ken: 1♂, Sugitate, 17. VI. 2017, Yu Hisasue. Kyûshû: Fukuoka-ken: 1 unsexed, Hikosan, Biol. Lab. KU, Soeda-machi, 8–10. V. 1957, K. Morimoto; 1 unsexed, same locality, 7. VI. 1993, S. Nomura; 3 unsexed, Hikosan, Biol. Lab. KU (750 m in alt.), Soeda-machi, 22. V. 2011, M. Maruyama (LFcfF); 1 unsexed, Kusaba, Nishi-ku, Fukuoka-shi, 28. IV. 2018, Tsubasa Nozaki; 1 unsexed, Motooka, Nishi-ku, Fukuoka-shi, 29. IV. 2020, Tsubasa Nozaki; 1 unsexed, Mt. Shioji, Otogana, Onojo-shi [33.5416°N, 130.5023°E], 28. V. 2017, Yu Hisasue (LFS). Saga-ken: 1 unsexed, Tôsen-zan, Ureshino-shi, 29. IV. 2018, Mitsuyasu Nishida (fit). Nagasaki-ken: 4 unsexed, Tanukinoo, Masuragahara-machi, Ômura-shi, 5. V. 2018, Mitsuyasu Nishida. Kumamoto-ken: 1 unsexed, Shiraga-dake, 4. XI. 1984, M. Ohara (HUM).
1–3 Lectotype of Homoeusa rufescens (Sharp, 1874): 1 habitus of te lectotype, male 2 labels of te lectotype 3 dissected parts of te lectotype 4 habitus of Homoeusa rufescens from non-type specimens, female 5 habitus of te holotype of Homoeusa ovata sp. nov., male.
It is distinguished from te other species of te genus by te following combination of characteristics: body small, slender and subparallel-sided; pronotum less transverse (PW/PL, 1.38–1.47), widest near middle, posterolateral angle obtuse, posterior margin hardly sinuate; apical lobe of male aedeagus thick with round sheet-like projection; apical lobe of paramere straight; velum broad and round.
Body (Figs 1, 4) small, very slender, subparallel-sided; dorsal surface mostly slightly polished.
Head (Fig. 6) relatively large, reddish brown; frontal margin with few long setae; carina of antennal insertion gently sinuate; eye large. Antennae (Fig. 7) stout, as long as head and pronotum combined, reddish brown, but segments I–IV and XI paler; segment I dilated, widest near apex; segment II slightly longer than III, widened apically; segment III widened apically; segment IV–X widened apically, each apical margin fringed with small teeth and longer than wide; segments IV as long as wide; segments V–X slightly wider than long; segment XI oblong oval. Labrum (Fig. 8), apical margin concave, surface with 20 setae; epipharynx with 2 pairs of sensillae on anterior margin, and 3 pairs of micro setae on lateral margin. Mentum (Fig. 9) with 3 pairs of setae and 1 pair of microsetae; anterior margin deeply concave. Prementum (Fig. 10) with many pseudopores, and with 2–3 real pores and 1 setal pore on each side near middle lateral margin. Ligula elongate, apical margin with 1 pair of spinule and several sensilla. Labial palpus, segment II and III each with 5 setae.
Pronotum (Fig. 6) convex, subrectangular, less transverse, widest near middle; posterolateral angle obtuse, posterior margin hardly sinuate, brownish red to brownish black; surface finely covered with setae and punctures. Elytra (Fig. 6) slightly widened posteriorly, posterior margins shallowly notched near lateral corners, brownish red; surface finely covered with setae and punctures, moderately reticulated. Mesoventral processes (Fig. 11) narrow, with medial carina forming Y-shaped, apex rounded; mesocoxal cavities separated; metaventral process weakly produced.
Abdomen elongate, slightly narrowed posteriad; surface sparsely covered with short setae and each posterior margin with long stout setae; polished and weekly reticulated.
Male: 8th sternite longer than wide, weakly rounded apically. Median lobe of aedeagus (Fig. 12), apical lobe of aedeagus thick with round flattened projection on ventral side; apical lobe of paramere (Fig. 13) short and straight; velum broad and round; ventral margin of paramerite almost straight.
Female: 8th sternite longer than wide, weakly rounded apically. Spermatheca (Figs 14–16), apical part moderately swollen; apical 3/5 with inner wall densely reticulated.
Body shape (N = 20): BL ≈ 1.6–2.7; AL, 0.64–0.75; HW, 0.41–0.47; PL, 0.44–0.50; PW, 0.61–0.70; EL, 0.38–0.44; EW, 0.65–0.73; HTL, 0.42–0.48; PW/PL, 1.38–1.49; PW/HW, 1.38–1.57; AL/HW, 1.45–1.77. Aspect ratio (length/width) of each antennal segment from I to XI (N = 6): 1.36–1.58, 1.43–1.71, 1.15–1.22, 0.63–0.77, 0.52–0.63, 0.43–0.53, 0.44–0.50, 0.39–0.49, 0.43–0.51, 0.49–0.56, 1.26–1.54.
Homoeusa rufescens Sharp, 1874 6 fore body 7 right antenna 8 labrum 9 mentum.
In most individuals, te pronotum tends to be brownish red, but te color varies from brownish red to brownish black.
Japan (Honshû, Shikoku, Kyûshû).
From April to July, this species can be found in te trails of te Lasius fuliginosus species group (Fig. 28). When they encounter host ants, they pause briefly until te ants ignore them and then start walking. TN observed that they ate prey that te ants were trying to carry but dropped. This species is sometimes observed to climb on food that te host ant is carrying and eat it (Fig. 29).
Lasius cf. fuliginosus, L. morisitai, L. nipponensis, L. spathepus.
Te original description suggested that te syntypes included another species (Sharp 1874). Based on our examination of te syntype, it includes two species, as mentioned in te original description. Here, te specimens of te more slender species that more closely match te original description are designated as te lectotype and paralectotype. Te specimens that were judged a different species were excluded from te syntypes of H. rufescens and included in te paratypes of te following species. As is often te case with old specimens, te proteins in te lectotype were denatured and potassium hydroxide did not sufficiently dissolve te muscle of te genital organs (Fig. 3), but te morphological characteristics of this species were fully observed.
Homoeusa rufescens Sharp, 1874 10 labium 11 meso-, metaventrite 12 median lobe of aedeagus from lateral view 13 paramere of aedeagus from lateral view 14–16 spermatheca.
In te original description, “Thiasophila rufescens” is “found with Formica japonica” (Sharp 1874). Ruzsky (1912) established te subgenus ‘Dendrolasius’ (=Lasius fuliginosus species group), with “Formica fuliginosa” as te type species. There were no Homoeusa rufescens specimens collected from Formica ants in te present study, so te syntypes were also likely collected from te Lasius fuliginosus species group. A single specimen was pinned with a Lasius japonicus (niger group), but this is considered to be a coincidence.
Homoeusa ovata Nozaki & Maruyama, sp. nov.
Japanese name: Hime-hirata-ariyadori Figs 5, 17–20, 21–27, 30, 31
Holotype. “Mt. Maruyama / Sapporo-shi / <Hokkaido, JAPAN> / 6. VI. 1988 / M. Maruyama leg. / trail of ants” (LFcfF). Paratypes. 1♂, (ex type series of “Thiasophila rufescens”), “Japan. Lewis.” / “Sharp Coll 1905-313” (no other data) (NHM). Paratypes. 1 unsexed (ex type series of “Thiasophila rufescens”), same data but labelled “rufescens var.?” (NHM). Russia: Primorskyi krai: 1 unsexed, Kamenushka, Ussuryisk (MMLASRUS07), 28. V. 2005, M. Maruyama (LFO); 1 unsexed, same locality (MMLASRUS09), 28. V. 2005, M. Maruyama (LFO) (IBSS); 1 unsexed, 1♂, same locality (MMLASRUS11), 28. V. 2005, M. Maruyama (LFN); 1 unsexed, Bukhta Vityaz, Poluostrov Gamov, Khasanskyi (MMLASRUS14), 29. V. 2005, M. Maruyama (LFO); 2 unsexed, same locality (MMLASRUS17), 31. V. 2005, M. Maruyama (LFO) (IBSS); 2 unsexed, same locality (MMLASRUS19), 31. V. 2005, M. Maruyama (LFFJ); 6 unsexed, 2♀, Okeanskaya, Vladivostok (MMLASRUS23), 1. VI. 2005, M. Maruyama (LFO); 6 unsexed, 1♂, 1♀, Nadezhdinskyi, Khasanskyi, 1. VI. 2005, M. Maruyama (LFFJ) (IBSS); 2 unsexed, 3♂, Arisimovka, 70 km E Vladivostok, [43.11°N, 132.41°E], 5. VI. 1993, L. Zerche (LFO); 2 unsexed, Sibir or. Ussuri Vladivostok, 1919, Dr. Jureček. Korea: 8 unsexed, 1♂, Janggoksa, Chilgab-san, Cheongyang-gun, Chungnam, 23. VI. 2000, Shuhei Nomura (LFS); 70 unsexed, 1♂, Jeonglyeong Chi Samnae Myeon Cheonla-buk Do, 12. VII. 1991, S. Nomura (LFO); 18 unsexed, 3♂, 1♀, same locality, 12. VII. 1991, S. Nomura. Japan: Hokkaido: 23 unsexed, Hyakumatsu-zawa, Sapporo-shi, 8. VI. 1998, M. Maruyama (LFcfF); 50 unsexed, Hakken-zan, Sapporo-shi, 31. V. 2002, M. Maruyama (LFcfF); 54 unsexed, same locality, 31. VI. 2002, M. Maruyama (LFcfF); 17 unsexed, 1♀, same locality, 1. VI. 2002, M. Maruyama (LFO); 92 unsexed, 1♂, 1♀, same locality, 1. VI. 2002, M. Maruyama (LFN); 267 unsexed, 2♂, 2♀, same locality, 1. VI. 2002, M. Maruyama (LFcfF); 2 unsexed, Kannon-zawa, Sapporo-shi, 1. V. 2002, M. Maruyama; 6 unsexed, same locality, 20. V. 2002, M. Maruyama; 27 unsexed, same locality, 31. V. 2002, M. Maruyama (LFcfF); 4 unsexed, 1♂, 5♀, same locality, 1 VI 2002, M. Maruyama (LFcfF); 23 unsexed, Maruyama, Sapporo-shi, 6. VI. 1998, M. Maruyama (LFcfF) (same data as holotype); 3 unsexed, Hitsujigaoka, Sapporo-shi, 18. V. 2000, M. Maruyama (LFS); 2 unsexed, Nopporo, 17. VII. 1990, M. Ohara (HUM); 12 unsexed, Nopporo, Ebetsu-shi, 13. VI. 1999, M. Maruyama (LFcfF); 20 unsexed, 2♀, Ôsawaguchi, Nopporo-shinrin-kôen, Ebetsu-shi, 16–19. VI. 2001, S. Hori; 46 unsexed, same locality, 16–19. VI. 2001, S. Hori (LFO); 25 unsexed, same locality, 2. VI. 1999, M. Maruyama; 2 unsexed, Tomambetsu, Nopporo, Ebetsu-shi, 29. V. 2002, M. Maruyama (LFcfF); 1 unsexed, Nozaki, Bihoro-chô, 23. VI. 2001, Y. Kida; 1 unsexed, Taihei, Maruseppu-chô, 29–31. V. 2000, Y. Kida; 104 unsexed, 1♀, same locality, 16–17. VI. 2000, Y. Kida; 4 unsexed, same locality, 11–12. VIII. 2000, Y. Kida (LFcfF); 36 unsexed, same locality, 19–21. VIII. 2000, Y. Kida (LFcfF); 1 unsexed, 2♂, 1♀, same locality, 25. VIII. 2000, M. Maruyama (LFcfF); 1 unsexed, Makoi, Shari-chô, 27. V. 2000, Y. Kida; 2 unsexed, same locality, 28. V. 2000, Y. Kida; 53 unsexed, 1♂, same locality, 24. VI. 2002, Y. Kida; 4 unsexed, same locality, 13. VI. 2002, Y. Kida; 44 unsexed, Kanayama, same locality, 18–24. VI. 2002, Yasunari Kida; 7 unsexed, Midorioka-kôen, Kitami-shi, 17. VI. 2001, M. Maruyama; 3 unsexed, Hebinuma, Teshio-gawa, Teshio-chô, 9. VII. 1992, S. Hori; 2 unsexed, Kamishunbetu, 20. VII. 1977, Naomi; 2 unsexed, Yûtoku, Ôtaki-mura, 24. VIII. 2001, M. Maruyama; 4 unsexed, Mukôengaru Engaru-chô, 25. V. 2000, Y. Kida (LFcfF); 2 unsexed, Miwa, Koshimizu-chô, 28. VII. 2001, S. Kuwahara; 1 unsexed, Mt. Kariba, Shiribeshi, 13. VI. 1986, S. Nomura; 1 unsexed, Himenuma, Rishiri Is, 4. IX. 1990, T. Kishimoto. Honshû: Aomori-ken: 1 unsexed, Hirosaki, 3. VII. 1960, Y. Murakami; 2 unsexed, same locality, 5. VII. 1960, Y. Murakami. Miyagi-ken: 1 unsexed, Aoba-yama, Sendai-shi, 17. VII. 2004, K. Mizota; 6 unsexed, Naruko-onsen, Naruko-chô, 14–17. VI. 1999, M. Sano (LFO). Akita-ken: 7 unsexed, 1♀, Tamagawa, Tazawako-machi, 12–13. VI. 1999, M. Sano (LFcfF). Fukushima-ken: 6 unsexed, Mizuhiki, Toteiwa-mura, 12. VI. 2004, H. Kamezawa (cKam); 33 unsexed, 2♂, Kashi Spa., Nishigo-mura, 16. VI. 1998, M. Maruyama (LFcfF); 12 unsexed, same locality, 17. VI. 1998, M. Maruyama (LFcfF); 1 unsexed, Nanairi, Hinoemata, 25. VII. 1996, S. Naomi. Ibaraki-ken: 2 unsexed, Inohana Pass, 29. V. 1994, Y. Hagino. Tochigi-ken: 1 unsexed, Yumoto, Nikkô, 29. IV. 1982, S. Naomi; 1 unsexed, Ichikai-machi, Haga-gun, 29. IV.–2. V. 2002, Seidai Nagashima. Gunma-ken: 5 unsexed, Sakurayama, Onishi-chô, 9. V. 1998, Koji Toyoda (LFS); 5 unsexed, same locality, 9. V. 1998, Shiho Arai (LFS); 2 unsexed, same locality, 9. V. 1998, Shiho Arai (LJ); 1 unsexed, same locality, 22. V. 1999, Shiho Arai (LFS); 10 unsexed, Nageishi-tôge, Fujioka-shi, 5. VI. 2001, T. Watanabe; 8 unsexed, Nakanojô-forest-park, Nakanojô-machi, Agatsuma-gun, 8. VI. 2001, T. Watanabe. Saitama-ken: 3 unsexed, Shiro-yama, Kamagata, Ranazan-machi, 17. VI. 2000, K. Toyoda; 1 unsexed, 1♂, Ranzan-keikoku, Kamagata-mura, Ranzan-machi, 14. IV. 2000, K. Toyoda; 1 unsexed, same locality, 25. IV. 2000, K. Toyoda; 1 unsexed, same locality, 21. IV. 1999, K. Toyoda; 4 unsexed, Shioyama, Ranzan-machi, 8. V. 1998, K. Toyoda; 7 unsexed, same locality, 10. V. 1998, K. Toyoda; 11 unsexed, same locality, 10. V. 1998, K. Toyoda (LFcfF); 3 unsexed, 1♂, Toki-gawa, Kamagata-mura, Ranzan-machi, 25. IV. 1999, K. Toyoda; 5 unsexed, Shiroishi-toge, Higashichichibu-mura, 20. VI. 1999, Shiho Arai; 1 unsexed, same locality, 17. VI. 2000, K. Toyoda (LFS); 4 unsexed, Nr. Shiroishi Pass Higashichichibu-mura, 27. VI. 1998, K. Toyoda; 1 unsexed, Chichibu-kôgen, Higashichichibu-mura, 3. VII. 1999, K. Toyoda; 1 unsexed, same locality, 3. VII. 1999, K. Toyoda; 3 unsexed, Hashidake, Chichibu-shi, 17. VII. 1999, Shiho Arai (LJ); 1 unsexed, same locality, 26. IV. 1998, K. Toyoda (LFS); 1 unsexed, Koakazawa, (1,000 m in alt), Iri Kawa, Mt.Hakutai san, Ootaki-chiku, Chichibu-shi, 7. VI. 2002, Koji Toyoda; 1 unsexed, Hashidate Riv., Chichibu-shi, 7. VI. 2002, Koji Toyoda; 3 unsexed, Mt. Jyouminesan Minao-chô, 29. V. 1999, Shiho Arai (LFcfF); 1 unsexed, Nr. Ohno Pass Takigawa-mura, 5. VIII. 1998, K. Toyoda (LFS). Chiba-ken: 2 unsexed, Matuzaki, Inzai-shi, 3. V. 1991, T. Takeda. Tôkyô-to: 1 unsexed, Mt. Takao, 1. V. 1985, S. Kubota; 35 unsexed, 3♂, 2♀, Takao-san (450 m in alt.), Hachiôji-shi, 4. VI. 2001, M. Maruyama (LFS); 4 unsexed, Takao-san, Hachiôji-shi, 1. VII. 1998, M. Maruyama; 2 unsexed, same locality, 4. VII. 1998, M. Maruyama; 1 unsexed, same locality, 4. VII. 1998, M. Maruyama (LFS); 1 unsexed, Oyama, Machida-shi, 19. V. 1991, T. Kishimoto. Kanagawa-ken: 6 unsexed, Kawana, Fujisawa-shi, 14. V. 2001, T. Watanabe (LFS); 4 unsexed, Jimmu-ji, Zushi-shi, 20. VI. 2003, M. Maruyama; 1 unsexed, Toya, Tsukui, 29. IV. 1977, Ryo Kiryu (SCM); 1 unsexed, same locality, 14. V. 1976, Ryo Kiryu (SCM); 1 unsexed, Nanzawa, Tsukui, 14. V. 1977, Ryo Kiryu (SCM); 1 unsexed, Hasuge-san, Aikô, 3. V. 1963, Ryo Kiryu (SCM); 1 unsexed, Minami-Ashigara, 11. II. 1975, Y. Hirano; 2 unsexed, Fudakake, Higashi-Tanzawa, 16. VI. 1984, Y. Hirano; 1 unsexed, Mt. Tanzawa, 26. II. 1973, Y. Hirano; 1 unsexed, Kawasaki, 1. V. 1985, 1. V. 1985; 1 unsexed, Kozuka-yama, Hakozaki-chô, 25–26. V. 1995, Yoshinori Kaneko, Akio Ito, Satoshi Tsuboyama; 6 unsexed, 1♂, Niiharu-shiminno-mori, Yokohama-shi, 21. V. 2001, T. Watanabe (LFO). Niigata-ken: 2 unsexed, Yuzawa-machi, Minami-uonuma-gun, 20–22. VI. 2002, S. Nagashima (LFS); 2 unsexed, Tairai, 3. VII. 1985, S. Nomura. Ishikawa-ken: 2 unsexed, Ichinose pass Shiramine-Village, 25. V–7. VI.2003, Katsuyuki Nakata (fit). Yamanashi-ken: 8 unsexed, Hikawarindô, Daibosatsu-rei, Koushû-shi, 24. VI. 2001, T. Watanabe; 4 unsexed, Ashiyu-onsen, Ashiyu-mura, 23. V. 2001, T. Watanabe (LFcfF); 1 unsexed, same locality, 24. V. 2001, T. Watanabe; 3 unsexed, Shiroidaira Dôshi-mura, 17.VII.2001, T. Watanabe; 4 unsexed, Gozaishi-kôsen (900 m in alt.), Nirasaki-shi, 25. VII. 2002, S. Nomura (LFN); 2 unsexed, Karumizu-rindô, (1400 m in alt.), Narusawa, 29. VI. 2011, T. Watanabe. Nagano-ken: 1 unsexed, Kakuma Valley, Sanada-machi, 17. VI. 2001, T. Watanabe; 1 unsexed, Midarebashi, Honjô-mura, 21. VII. 1999, T. Watanabe; 52 unsexed, Penshionmura, Hara-mura, 11. VII. 1999, Shiho Arai (LFO); 2 unsexed, Otari-onsen (1100 m in alt.), Otari-mura, Kita-azumi-gun, 16. V. 2004, H. Kamezawa (cKam); 2 unsexed, Fujii, Satoyamabe, Matsumoto-shi, 9. VI. 2004, T. Komatsu; 1 unsexed, same locality, 11. VI. 2004, T. Komatsu; 1 unsexed, same locality, 21. VI. 2004, T. Komatsu. Gifu-ken: 6 unsexed, Ogamigo (800 m in alt.) Shôkawa-mura, 5–6. VIII. 1998, M. Maruyama (LFS); 4 unsexed, Mt. Kinkazan, Gifu-shi, 11. VI. 2003, K. Kinomura (LFS); 1 unsexed, Isshiki, Shôkawa-chô, Takayama-shi, 1. VIII. 2004, K. Kinomura (LFN); 51 unsexed, Isshiki, Shôkawa-chô, Takayama-shi, 8. VI. 2013, K. Kinomura (LFM); 29 unsexed, Nabedaira-kôgen, Kansaka, Okuhida-onsenkyô, Takayama-shi, 30. VI. 2013, K. Kinomura (LFN); 20 unsexed, Nabedaira-kôgen, (1305 m in alt.) Kansaka, Okuhida-onsenkyô, Takayama-shi, (1305 m in alt.), 30. VI. 2013, K. Kinomura (LFN). Wakayama-ken: 1 unsexed, Mt. Gomandan, 22–23. VI. 1981, S. Naomi. Tottori-ken: 1♂, Mt. Daisen, 3–5. VI. 1980, S. Naomi; 3 unsexed, same locality, 10. VI. 1986, S. Nomura (LFS); 10 unsexed, 1♂, Urahikimi, Shimane-ken, 6. VI. 1988, S. Nomura (LFS). Okayama-ken: 2 unsexed, Ono Shine, Kawakami, Ohara-chô, Mimasaka-shi, 5. V. 2009, Yoshifumi Fujitani; 1 unsexed, same locality, 24. V. 2009, Yoshifumi Fujitani; 1 unsexed, same locality, 7. VI. 2009, Yoshifumi Fujitani. Hiroshima-ken: 11 unsexed, Nakatsuya, Hatsukaichi-shi, 7. VI. 1987, S. Nomura; 1 unsexed, Mt. Garyu, 27. VI. 1987, S. Nomura (LFcfF). Yamaguchi-ken: 10 unsexed, Nishimagura, (100 m in alt.), Kusunoki, 30. V. – 1. VI. 2000, Toshio Kishimoto; 3 unsexed, Momijidani park, Yokoyama, Iwakuni-shi, 28. V. 2011, M. Shimono (LFS). Shikoku: Kagawa-ken: 5 unsexed, Furodani, Miki-chô, 30. VII. 2000, K. Izawa (LFcfF); 108 unsexed, 3♂, 1♀, Ôtaki-san, Shionoe-chô, 2. VI. 2001, M. Maruyama et al. (LFN); 21 unsexed, Atago-yama, Kotohira-chô, 1. VI. 2001, M. Maruyama et al. (LFS); 22 unsexed, Fujio-jinja, Nishi-ueta-chô, Takamatsu-shi, 31. V. 2001, M. Maruyama et al. (LFN); 2 unsexed, same locality, 1. VI. 2001, M. Maruyama et al. (LFN); 22 unsexed, Daisen-zan, Kotonami-chô, 1. VI. 2001, M. Maruyama et al. (LFM); 13 unsexed, Usa-jinja, Nagaona, Sanuki-shi, 31. V. 2001, M. Maruyama et al. (LFS); 3 unsexed, Shirahige-jinja, Ayakami-chô, 25. IV. 2004, H. Fujimoto (LFM). Ehime-ken: 1♂, Sugitate, 17. VI. 2017, Yu Hisasue; 2 unsexed, Waki-ga-fuchi Park (120–220 m in alt.), Sue-machi, Matsuyama-shi [33.87°N, 132.83°E], 4. V. 2017, Yu Hisasue (Tullgren); 1 unsexed, Mt. Ishizuchi (1400 m in alt.), Saijô-shi, 29. VI. 2014, Yu Hisasue; 1 unsexed, Minamikume-machi, Matsuyama-shi [33.8333°N, 132.8184°E], 25. IV. 2015, Yu Hisasue (Tullgren). Kyûshû: Fukuoka-ken: 1 unsexed, Hakozaki, Fukuoka-shi, 12. V. 1979, K. Yamagishi; 2 unsexed, 1♂, Hikosan, Biol. Lab. KU (750 m in alt.), Soeda-machi, 22. V. 2011, M. Maruyama (LFcfF). Saga-ken: 2 unsexed, Mt. Mifume, 15. V. 2019, S. Nomura; 2 unsexed, Mt. Kurokami-yama (400 m in alt.), Takeo-shi [33.2130°N, 129.9044°E], 9. V. 2021, Yu Hisasue (LFcfF); 4 unsexed, 1♂, Kurokami-yama, Arita-chô, 15. V. 2019, Mitsuyasu Nishida. Nagasaki-ken: 3 unsexed, 1♂, Tanukinoo, Masuragahara-machi, Ômura-shi, 5. V. 2018, Mitsuyasu Nishida; 1 unsexed, Todoroki Valley, 1. VI. 1987, S. Naomi; 1♂, Suwa Shine, Nagasaki-shi, 2. V. 1985, S. Nomura; 1 unsexed, Tomikawa-keikoku, Isahaya-shi, 28. IV.–1. V. 2008, T. Iwai.
It is distinguished from te other species of te genus by te following combination of characteristics: body subparallel-sided; pronotum convex and strongly transverse (PW/PL, 1.54–1.68), widest near middle, sides barely protrude, posterolateral angle obtuse and posterior margin hardly sinuate; apical lobe of male aedeagus S-shaped with small lanceolate sheet-like projection; apical lobe of paramere (Fig. 24) curved ventrally and thickened apicad with four setae gathering to apex; velum emarginate at middle. This species is especially similar to H. rufescens and slightly resembles H. japonica and H. prolongata in habitus. However, this species is easily separated from te three species by te shape of aedeagus and dorsal characteristics: H. rufescens by pronotum aspect ratio (less transverse in H. rufescens); H. japonica by body size and pronotum shape (posterior margin is moderately sinuate in H. japonica); and H. prolongata by pronotum shape (more flattened and hemicircular, posterolateral angle gently acute in H. prolongata).
Body (Fig. 5) small, slender, subparallel-sided; dorsal surface mostly moderately polished.
Head (Fig. 17) relatively large, reddish brown; frontal margin with few long setae; carina of antennal insertion simply bent; eye large. Antennae (Fig. 18) stout, as long as head and pronotum combined, reddish brown, but segments I–III and XI paler; segment I dilated, widest near apex; segment II longer than III, widened apically; segment III widened apically; segment IV–X widened apically, each apical margin fringed with small teeth and longer than wide; segments IV as long as wide; segments V–X slightly wider than long; segment XI oblong oval. Labrum (Fig. 19), apical margin weekly concave surface with 20 setae; epipharynx with 2 pairs of sensillae on anterior margin, and 3 pairs of micro setae on lateral margin. Mentum (Fig. 20) with 3 pairs of setae and 1 pair of microsetae; anterior margin shallowly concave. Prementum (Fig. 21) with many pseudopores, and with 4–5 real pores and 1 setal pore on each side near middle lateral margin. Ligula elongate, apical margin with 1 pair of spinula and several sensilla. Labial palpus (Fig. 21), segment II and III each with 5 setae.
Homoeusa ovata sp. nov. 17 fore body 18 right antenna 19 labrum 20 mentum.
Pronotum (Fig. 17) convex, subrectangular, strongly transverse, widest near middle, posterolateral angle obtuse, posterior margin hardly sinuate; brownish red to brownish black; surface finely covered with setae and punctures, gently polished. Elytra (Fig. 17) slightly widened posteriorly, posterior margins shallowly notched near lateral corners, brownish red; surface finely covered with setae and punctures, gently polished. Mesoventral (Fig. 22) processes narrow, with medial carina, forming Y-shaped, apex rounded; mesocoxal cavities almost separated; metaventral process gently produced.
Abdomen elongate, gently narrowed posteriad; surface sparsely covered with short setae and each posterior margin with long stout setae; gently polished and weakly reticulated.
Male: 8th sternite longer than wide, rounded apically. Median lobe of aedeagus (Fig. 23), apical lobe of male aedeagus s-shaped with small lanceolate flattened projection; apical lobe of paramere (Fig. 24) curved ventrally and thickened apicad with 4 setae gathering to apex; velum emarginated at middle; ventral margin of paramerite strongly concaved.
Female: 8th sternite longer than wide, rounded apically. Spermatheca (Figs 25–27), apical part weakly swollen; apical half with inner wall densely reticulated.
Homoeusa ovata sp. nov. 21 labium 22 meso-, metaventrite 23 median lobe of aedeagus from lateral view 24 paramere of aedeagus from lateral view 25–27 spermatheca.
Body shape (N = 20): BL ≈ 1.91–2.97; AL, 0.61–0.76; HW, 0.45–0.51; PL, 0.45–0.53; PW, 0.72–0.84; EL, 0.38–0.48; EW, 0.73–0.87; HTL, 0.47–0.53; PW/PL, 1.55–1.68; AL/PL, 1.26–1.68; HTL/PL, 0.93–1.12. Aspect ratio (length/width) of each antennal segment from I to XI (N = 6): 1.29–1.67, 1.29–1.75, 0.87–1.2, 0.72–0.82, 0.50–0.55, 0.43–0.50, 0.41–0.55, 0.33–0.61, 0.38–0.48, 0.41–0.54, 1.25–1.48.
In most individuals, te pronotum tends to be darker, but te color varies from brownish red to brownish black.
Russia (Primorskyi krai), Korea, Japan (Hokkaido, Honshû, Shikoku, Kyûshû).
This species behaves almost te same as H. rufescens. It is also observed to feed on prey among ants and sometimes climbs on, and eats food carried by ants (Fig. 31).
Photos of alive individuals of Homoeusa spp. in trails of Lasius fuliginosus species group in field environments 28, 29 H. rufescens: 28 waking on a trail of Lasius morisitai 29 feeding on food being carried by ant workers (photographed by Taku Shimada) 30, 31 H. ovata sp. nov.: 30 waking on a trail of Lasius cf. fuliginosus 31 feeding on food being carried by ant workers (photographed by Kyoichi Kinomura).
Lasius fuji, L. cf. fuliginosus, Lasius morisitai, L. nipponensis, L. orientalis, L. spathepus.
As Quinet and Pasteels (1996) reported, Homoeusa acuminata has been observed to climb on prey being carried by ants and feed on it, simultaneously hitchhiking and stealing food. This beetle has also been reported to rarely feed directly on food not yet carried by ants (Quinet and Pasteels 1995). Similar behaviors have been observed in H. rufescens and H. ovata sp. nov., such as stealing food while boarding and being ignored by te ants during te process. However, H. rufescens and H. ovata sp. nov. have also been observed feeding on food that ants are trying to carry and on prey dropped by ants. These two species may have a wider range of foraging strategies than H. acuminata and may also scavenge and not merely be kleptoparasitic. Te optimal foraging strategy for these beetles near an ant trail may depend on te level of ant activity.
Checklist of te genus Homoeusa Kraatz, 1856
1. Homoeusa acuminata (Märkel, 1842): 143.
Euryusa acuminata Märkel, 1842
Homoeusa tomentosa Reitter, 1909: 38
Distribution. Azerbaijan, Austria, Belgium, Belarus, Croatia, Russia (Central European Territory), Czech Republic, France, Great Britain, Germany, Georgia, Greece, Hungary, Italy, Te Netherlands, Polen, Romania, Slovakia, Spain, Russia (South European Territory), Switzerland, Russia (Far East).
2. Homoeusa chinensis Pace, 1999: 150.
3. Homoeusa japonica Sharp, 1874: 5.
Distribution. Japan (Honshu, Shikoku, Kyushu).
Host. L. cf. fuliginosus, L. morisitai, L. spathepus.
4. Homoeusa laevigata Sharp, 1888: 283.
5. Homoeusa longicornis Sharp, 1888: 283.
Distribution. Japan (Hokkaido, Honshu).
Host. L. cf. fuliginosus, L. morisitai, L. spathepus.
6. Homoeusa ovata sp. nov.
Distribution. Russia (Primorskyi krai), Korea, Japan (Hokkaido, Honshu, Shikoku, Kyushu).
Host. L. fuji, L. cf. fuliginosus, L. morisitai, L. nipponensis, L. orientalis, L. spathepus.
7. Homoeusa prolongata Sawada, 1970: 57.
Distribution. Japan (Hokkaido, Honshu, Shikoku, Kyushu).
8. Homoeusa rufescens (Sharp, 1874): 5.
Thiasophila rufescens Sharp, 1874
Distribution. Japan (Honshu, Shikoku, Kyushu).
Host. L. cf. fuliginosus, L. morisitai, L. nipponensis, L. spathepus.
9. Homoeusa sibirica Rambousek, 1921: 86.
Distribution. Russia (Far East), Korea (South).
10. Homoeusa taiwanensis Pace, 2010: 29.
11. Homoeusa crinitula (Casey, 1900): 53.
Soliusa crinitula Casey, 1900
Homoeusa frosti (Casey, 1911): 53
Soliusa frosti Casey, 1911
Distribution. America (New York, Massachusetts).
12. Homoeusa crassicornis (Casey, 1893): 595.
Myrmobiota crassicornis Casey, 1893
We would like to express our gratitude to Dr Takato Kobayashi (Yamanashi Institute of Environmental Science, Yamanashi pref., Japan), Mr Hiromichi Obata (Kanagawa pref., Japan), Dr Shuhei Nomura (NSMT), Mr Shigehisa Hori (Hokkaido Museum, Hokkaidô, Japan), Dr Fuminori Ito (Kagawa University), Mr Yasunari Kida (Maruseppu Insectarium, Hokkaidô, Japan), Mr Takashi Watanabe (Kanagawa pref., Japan), Mr Koji Arai [Koji Toyoda], Ms Shiho Arai (Ranzan-machi, Saitama pref.), Mr K. Izawa, Mr Hiromu Kamezawa (Saitama pref.), Mr Kyoichi Kinomura (Gifu pref.), Mr Yu Hisasue (Kyushu University, Fukuoka, Japan), and all other collectors for kindly offering te specimens. We would like to show our great appreciation Mr Taku Shimada (Tokyo pref.), K. Kinomura and Ms Mari Muto (Gifu pref.) for kindly allowing te use of photos of alive individuals in fields. MM thanks Dr Roger Booth (NHM) for making loan of te type material, Dr Victor Kuznetsov and Dr Yuri Tshistjakov (IBSS) for arranging his research permit and collecting trip around Vladivostok in 2005 and Mr Yoshiyuki Nagahata for helping him during te trip. We also greatly appreciate Dr Kazuo Ichikawa for his financial support for our research. This study was supported in part by a JSPS KAKENHI Grant Number 19H03285. Finally, we would like to express our gratitude to anonymous reviewers for their helpful comments on te manuscript.
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