Taxonomy of Homoeusa Kraatz, 1856 (Coleoptera, Staphylinidae, Aleocharinae) from the East Palearctic: II. Revision of Japanese species

Taxonomy of Homoeusa Kraatz, 1856 (Coleoptera, Staphylinidae, Aleocharinae) from the East Palearctic: II. Revision of Japanese species Tsubasa Nozaki1,2, Munetoshi Maruyama2 1 Entomological Laboratory, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 819-0395, Japan 2 The Kyushu University Museum, Fukuoka 812-8581, Japan https://zoobank.org/0F162CF0-9B4E-476B-A832-91BBCCD00D6A Corresponding author:Tsubasa Nozaki (dosanko.lathr[email protected]) Academic editor: Emmanuel A. Varela ♦ Received 12 May 2025 ♦ Accepted 9 October 2025 ♦ Published 3 December 2025 Abstract Members of the myrmecophilous rove beetle genus Homoeusa Kraatz, 1856 are symbiotically associated with ants of the genus Lasius Fabricius, 1804 with a high degree of host specificity, making them biologically intriguing subjects for studying myrmecophily and host–parasite interactions. Their identification, however, remains challenging. Diagnostic characteristics, particularly the genitalia, have not been well documented for the three previously described species of the genus from Japan, and the presence of undescribed species has been suggested. In this study, we revise the taxonomy of Japanese Homoeusa, providing detailed descriptions and illustrations of seven species, including three new species: Homoeusa translucida sp. nov., Homoeusa brevitarsis sp. nov., and Homoeusa gigantea sp. nov. Additionally, we present ecological information for each species and discuss their interactions with their host ants. Key Words Aleocharine, description, Dinardina, inquiline, Lasius, myrmecophily, new species, rove beetles Introduction The genus Homoeusa Kraatz, 1856 is a myrmecophilous rove beetle group associated with Lasius Fabricius, 1804 ants (subfamily Formicinae, tribe Lasiini). Currently, this genus comprises 12 species that are distributed across the Holarctic region (Nozaki and Maruyama 2022a). This series of papers aims to revise the species-level taxonomy of the genus in the East Palearctic region, with a particular focus on the fauna of East Asia and the Russian Far East. The present paper focuses on the Japanese members of this genus. To date, six species are known from Japan. Of these, four were described by David Sharp based on specimens collected by George Lewis (Sharp 1874, 1888). Subsequently, Sawada (1970b) described a single species, H. prolongata Sawada, 1970. In our previous paper, we formally verified the combination of Homoeusa rufescens (Sharp, 1874) and described one species, H. ovata Nozaki & Maruyama, 2022. Detailed descriptions and illustrations of the genitalia are provided for three species: H. rufescens, H. prolongata, and H. ovata. However, this information is not available for the remaining three species. Through extensive collection efforts and the examination of historical specimens, two previously undescribed species have been discovered (Maruyama et al. 2013). Additionally, a previously unknown species from the Kii Peninsula of Honshu has been identified, further emphasizing the need for comprehensive taxonomic studies in underexplored regions. This paper builds on the legacy of previous studies by revisiting historical specimens and integrating new materials, offering a complete re-evaluation of the Japanese Homoeusa species. The present paper provides redescriptions of four previously known Japanese species and descriptions of three new species. Besides detailed morphological descriptions, this study provides ecological insights into the species of Homoeusa. These include geographic distribution, host ant associations, seasonal activity patterns of adults, collection methods, and behaviors observed in the presDtsch. Entomol. Z. 72 (2) 2025, 525–555|DOI 10.3897/dez.72.158689 Copyright Tsubasa Nozaki & Munetoshi Maruyama. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 526 ence of host ant workers. Such ecological observations not only complement taxonomic findings but also contribute to a broader understanding of the interactions between these beetle inquilines and their ant hosts. Finally, we discuss aspects of their life cycle and behavior, highlighting potential adaptive traits that may have evolved in response to their myrmecophilous lifestyles. Materials and methods The materials used in this study have been deposited in the following institutions and private collections: cKam The private collection of Hiromu Kamezawa (Saitama-ken, Japan) cSch M. Schülke collection, Berlin, Germany (belonging to Museum für Naturkunde, Berlin, Germany) EUMJ Ehime University Museum, Japan (H. Yoshitomi) HUM The Hokkaido University Museum, Sapporo (M. Ôhara) IPMM Iwate Prefectural Museum, Morioka, Japan (S. Watanabe) KPMNH Kanagawa Prefectural Museum of Natural History (K. Watanabe) KUM The Kyushu University Museum (M. Maruyama) NHM The Natural History Museum, London (K. Matsumoto) NHMW The Natural History Museum Vienna (M. Seidel) NSMT National Museum of Nature and Science, Tsukuba (S. Nomura) OUAVM The Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan SCM Sagamihara City Museum, Kanagawa, Japan (S. Shimamoto) SPMN Museum of Natural and Environmental History, Shizuoka (T. Kishimoto) TUA Laboratory of Entomology, Faculty of Agriculture, Tokyo, University of Agriculture, Kanagawa, Japan (T. Ishikawa) The morphological observations were made using an Olympus SZX12 stereomicroscope. For measurements, 5–15 photographs per specimen were captured using a Canon EOS Kiss X5 camera mounted on the Olympus SZX12 stereomicroscope, and the following parts were measured using ImageJ 1.54g. 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 For the dissection and preparation of permanent slides, Maruyama (2004) was referenced. Habitus photographs were taken with a Canon 7D camera, Canon MP-E 65 mm f/2.8 1–5X macro lens, and Neewer TT560/1Y strobe. The images were stacked using ZERENE STACKER ver. 1.04 (Zerene Systems, LLC). The dissected parts were drawn using a Nikon Eclipse Ci microscope with an Olympus drawing tube attached with a Nikon Y-IDT and imaged using a Canon Eos Kiss X8i mounted on an Olympus BX50 microscope. The terminology of the internal structure of the male aedeagus follows the description of H. prolongata (Sawada 1970b), and that of the spermatheca follows Maruyama (2006), as shown in Fig. 1A, B, respectively. A distribution map was constructed using QGIS 3.34 Prizren. Host ant workers collected with the Homoeusa species were mostly identified by MM and F. Ito, and some by TN, K. Kinomura, and Y. Hisasue. Based on the scientific names of Lasius ants, we followed Bolton (1995), Radchenko (2005), and Boudinot et al. (2022), who referred to species groups as in Nozaki and Maruyama (2022a). The identified symbiotic host species and relevant data are as follows. Lasius fuliginosus group LFN Lasius nipponensis Forel, 1912 LFcfF Lasius cf. fuliginosus LFM Lasius morishitai Yamauchi, 1979 LFS Lasius spathepus Wheeler, 1910 LFO Lasius orientalis Karavaiev, 1912 Lasius niger species group LNH Lasius hayashi Yamauchi & Hayashida, 1970 LNJ Lasius japonicus Santschi, 1941 LNP Lasius productus Wilson, 1955 LNS Lasius sakagamii Yamauchi & Hayashida, 1970 Lasius umbratus group LUM Lasius meridionalis (Bondroit, 1920) LUU Lasius umbratus (Nylander, 1846) In addition to collections by MM, newly collected Homoeusa specimens by TN from 2021 to 2024 were included. Collection methods usually involved picking the insects from foraging trails or nests under stones. Shifting litter around foraging trails or destroying nests in decayed wood was also adopted. TN frequently set bait near foraging trails/nests in the litter or soil and under stones. If successful, it resulted in a small swarm of worker ants (Fig. 1C), and Homoeusa adults could be collected by shifting such clusters. Some specimens were collected using flight intercept traps (FIT) and a malaise trap. Behavioral observations were conducted at their habitat outdoors and at the laboratory or accommodations just after collecting (mentioned as “indoors” or “indoor observation”). Videos were recorded using Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 527 Figure 1. Explanations on research methods. A. Terminology of aedeagal median lobe (Homoeusa prolongata); al – apical lobe; av – apical valves; cp – copulatory piece; B. Terminology of spermatheca (Homoeusa laevigata); ap – apical part; bp – basal part; C. A simple bait trap set under stone with a swarm of Lasius meridionalis; D. A small camera shooting video of a Lasius fuliginosus group sp. foraging trail; E. Indoor observation setup using a plastic container with plaster. a Camera Ricoh WG5, which was set in front of the foraging trails outside (Fig. 1D) or indoors in plastic containers with plaster (Fig. 1E). Sometimes during indoor observations, a Nikon Digital Sight DS-Fil camera attached to a microscope Leica S8APO was also used. Still images were captured from the videos using Adobe Premiere Elements 2025. All figures were edited and combined with Photoshop Elements 2025. Results Tribe Oxypodini Thomson, 1859 Subtribe Dinardina Mulsant & Rey, 1873 Genus Homoeusa Kraatz, 1856 Homoeusa Kraatz, 1856: 76. Myrmobiota Casey, 1893: 594. Soliusa Casey, 1900: 53 Note. See Nozaki and Maruyama (2022a) for a detailed synonymic list and the diagnosis of this genus. Remarks. No apparent sexual dimorphism other than in the genitalia or terminalia has been reported in this genus. However, based on extensive examination of several species, females were often found to have shorter and denser stout setae on the middle posterior margin of the 8th sternite than males did (Fig. 9F, G). Moreover, there are more or less interspecific variation in the marginal shape of the 8th sternite on each sex. Therefore, we provide illustrations and descriptions of this characteristic for all the species, including the well-described species in our previous papers (Nozaki and Maruyama 2022a, 2022b), Homoeusa rufescens and H. ovata. To measure the antennae, we provided the width and aspect ratio of each segment in the previous paper. However, they usually have elliptical cross-sections, which can cause instability during measurement. Therefore, we provided the relative length of each segment instead. The males have various parameral apical lobe shapes and arrangements of the four setae across species. Although strict homology is not available for these four setae, for the convenience of a comparative description, we named them as Sawada (1970b) did for H. prolongata. Each seta typically has the following characteristics in Homoeusa (e.g., Fig. 13H): a, longest and distributed at the most basal position; b, medium in length and distributed dorsally; c, medium in length and distributed ventrally; d, shortest, thinnest, and distributed at the most apical position. Key to species of Homoeusa in Japan 1 Pronotum strongly transverse, 1.84–2.05 as wide as long (Fig. 4B); pronotum and elytra sparsely covered with modified stout setae (Fig. 4C) ........................................................................................................ Homoeusa translucida sp. nov. – Pronotum moderately transverse, 1.38–1.80 times as wide as long (e.g., Fig. 7B); pronotum and elytra moderately densely covered with normal setae (e.g., Fig. 7B, C) ................................................................................................... 2 2 Metatarsus shorter than half of the metatibia (Fig. 17F, G) ............................................... Homoeusa brevitarsis sp. nov. – Metatarsus longer than half of the metatibia (Fig. 3E) ............................................................................................... 3 3 Antennal segment 10th more transverse (e.g., Fig. 13A) .............................................................................................. 4 – Antennal segment 10th less transverse (Fig. 9A, B) ..................................................................................................... 6 4 Pronotum weekly transverse (PW/PL, 1.38–1.49); median lobe of aedeagus having round flattened projection on ventral side (fig. 12 in Nozaki and Maruyama 2022a) .......................................................... Homoeusa rufescens (Sharp, 1874) – Pronotum strongly transverse (PW/PL, 1.54–1.68); median lobe of aedeagus without round flattened projection on ventral side ............................................................................................................................................................... 5 dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 528 5 Metaventral process distinctly produced (fig. 22 in Nozaki and Maruyama 2022a); median lobe of aedeagus, apical lobe s-shaped in lateral view with small lanceolate flattened projection on ventral side (fig. 23 in Nozaki and Maruyama 2022a) .......................................................................................................Homoeusa ovata Nozaki & Maruyama, 2022 – Metaventral process slightly or indistinctly produced (e.g., Fig. 13D); median lobe of aedeagus, apical lobe not s-shaped without flattened projection ................................................................................. Homoeusa prolongata Sawada, 1970b 6 Postero-lateral angle of pronotum acute (e.g., Fig. 15B); metaventral process slightly or indistinctly produced (e.g., Fig. 15D) ......................................................................................................................................................................... 7 – Postero-lateral angle of pronotum obtuse or around 90 degrees (e.g., Fig. 9C); metaventral process distinctly produced (e.g., Fig. 9E) ............................................................................................................................................................ 8 7 Pronotum and elytra covered with long setae (Fig. 15B, C); elytral postero-lateral notch deep (Fig. 15B); mesocoxal cavities almost separated (Fig. 15D) ................................................................................... Homoeusa gigantea sp. nov. – Pronotum and elytra covered with distinctly shortened setae (Fig. 7B, C); elytral postero-lateral notch shallow (Fig. 7B); mesoventral process reaching only middle of mesocoxal cavities (Fig. 7D) .................. Homoeusa laevigata Sharp, 1888 8 Apical lobe of paramere moderately long (Fig. 9I, J), length about half of whole paramere, apex simply round ............. ................................................................................................................................... Homoeusa japonica Sharp, 1874 – Apical lobe of paramere extremely long (Fig. 11I), length a little over half of whole paramere, apex blade-shaped ........ ................................................................................................................................Homoeusa longicornis Sharp, 1888 Homoeusa translucida Nozaki & Maruyama, sp. nov. https://zoobank.org/B3ED5737-79D9-4A24-B513-344F726D937B Figs 3A, 4A–I, 5A, B Japanese name: Sukashi-hirata-ariyadori “Homoeusa sp.4”: Saitoh et al. 2017: 33, fig. 65 (recorded from Kanagawa-ken). “Oxypodini? sp.2”: Nishida 2019: 135, fig. 11 (recorded from Saga-ken). Material examined. Holotype (Fig. 1A) • ♂; “Mt. Minoyama, Minano,” / “Saitama, Japan, alt. 500-” / “560 m; MC: 5439-00-69.” / “21.V.1999 M. UCHIDA” (KUM). Paratypes. Japan: Hokkaido • 1♀; Nopporo Forest Park, Sapporo-shi; 24.V. & 5.VI.2008; Tomáš Lackner leg. (NHMW). Honshu: Kanagawa-ken • 1 ex.; Yakunimi-yama, Hadano-shi; 10.V.2013; O. Saitoh leg. (KPMNH) • 1♀; same locality; 24.V.2014; O. Saitoh leg. FIT (KPMNH) • 1♂; same locality; 8.VI.2014; O. Saitoh leg. FIT (KPMNH). Shimane-ken • 1 ex.; Urahikimi, Masuda-shi; 6.VI.1998; S. Nomura leg. (KUM). Okayama-ken • 1 ex.; Nagi-yama, Nagi-chô; 17.V.2005; W. Suzuki leg. (KUM). Shikoku: Ehime-ken • 1 ex.; Mt. Sara-ga-mine, Toon-shi; 13.VII.2008; Y. Yamauchi leg. (EUMJ). Kochi-ken • 1 ex.; Kajigamori, Ôtoyo-chô; 20.V.1951; M. Miyamoto leg. (EUMJ). Kyushu: Fukuoka-ken • 1 ex.; Takasubaru, Mt. Hikosan [33.4883, 130.9174], Soeda-machi; 27.VI.2021; TS. (Tsubasa) Nozaki leg. LUM (KUM) • 1 ex.; Bio. lab. KU. Mt. Hikosan, Soeda-machi; 28.III–27.IV.2023; J. Abe leg. Malaise trap (KUM). Saga-ken • 1♂; Mt. Seira, Imarishi; 28.V.1984; S. Nomura leg. (KUM) • 1♂; Kurokami-yama, Arita-cho; 18.V.2018; M. Nishida leg. FIT (KUM). Diagnosis. This species can be easily distinguished from the other species of the genus by the following combination of characteristics: body color yellowish orange; pronotum strongly transverse (PW/PL, 1.84–2.05), postero-lateral angle distinctly acute (Fig. 4B); metaventral process weakly produced (Fig. 4D); pronotum and elytra sparsely covered with modified stout setae (Fig. 4B, C); median lobe of aedeagus apical lobe straight, apex round and slightly humped in lateral view, apical valves very large and cheliform (Fig. 4G); spermatheca (Fig. 4I) L-shaped, basal part very long. This species is slightly similar to H. gigantea sp. nov. in color but differs in its pronotal and setal shapes. Description. Body (Figs 3A, 5B) small, broad; dorsal surface mostly polished. Head large; color yellowish orange; eyes large. Antennae (Fig. 4A) long; relative length of each antennal segment from first to 11th, 2.48: 1.96: 1.39: 1.22: 1.04: 1.09: 1.00: 1.15: 1.15: 1.37: 3.26. Thorax. Pronotum (Fig. 4B) subrectangular, strongly transverse (PW/PL, 1.84–2.05), widest near middle, postero-lateral angle distinctly acute, posterior margin distinctly sinuate, color yellowish orange, subtransparent, surface sparsely covered with modified stout setae and punctures, gently polished without reticulation. Elytra (Fig. 4B, C) slightly widened posteriad, widest at middle, then narrowed roundly, posterior margins shallowly notched near lateral corners, color yellowish orange, subtransparent, surface sparsely covered with modified stout setae and punctures, gently polished without reticulation. Hind wings developed. Mesoventral process (Fig. 4D) narrow, with weak medial carina, apex gently pointed, reaching posterior 1/3 of mesocoxal cavities, Metaventral process weakly produced. Abdomen elongate, narrowed posteriad; surface sparsely covered with short setae and each posterior margin with long stout setae; covered with fine vertical furrows. Male: 8th sternite (Fig. 4E) widely protruding at middle of posterior margin; median lobe of aedeagus (Fig. 4G) elongate, length about 0.57 mm, apical lobe straight, apex round and slightly humped in lateral view, apical valves large and cheliform, dorsal arms boot-shaped; basal part of copulatory piece very large and having clawshaped projection, basal corner acutely pointed. Paramere (Fig. 4H) length about 0.59 mm; apical lobe of paramere long, length over 1/3 of whole paramere, curved ventrally, slightly dilated apicad; four setae, c located a little more apically than b; velum narrow and membranous. Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 529 Female: 8th sternite (Fig. 4F) slightly protruding at the middle of posterior margin; spermatheca (Fig. 4I) L-shaped, basal part very long, apex of basal part not swollen, base almost straight and only slightly swollen. Measurements (in mm) and ratios. Body parts (N = 10): BL ≈ 2.13–2.91; AL, 0.93–1.07; HW, 0.51–0.57; PL, 0.5–0.59; PW, 1–1.13; EL, 0.47–0.52; EW, 0.98–1.16; HTL, 0.69–0.76; PW/PL, 1.84–2.05; AL/PL, 1.69–1.95; HTL/PL, 1.29–1.46. Distribution. Japan (Honshu, Shikoku, Kyushu) (Fig. 5A). Symbiotic hosts. Lasius umbratus species group: L. meridionalis (only single example). Bionomics. Two individuals were collected by FIT, and a single individual was collected by the malaise trap. The behavior with the host ants is unknown. Remarks. This species is relatively rare, and most specimens have no information regarding their host ants. However, a single specimen (Fig. 5B) was collected with L. meridionalis using a bait trap set by TN under the stone where the ant trail was located. Etymology. The specific name is derived from the Latin adjective, which means “transparent” and refers to the character of the pronotum of this new species. Homoeusa rufescens (Sharp, 1874) Fig. 6A–C, G (Japanese name: Hoso-hirata-ariyadori) 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); Schülke and Smetana 2015: 682 (catalogue); Nozaki and Maruyama 2022a: 42 (the combination confirmed). Figure 2. Type materials deposited in NHM. A–C. The habiti of the type specimens of three species; A. The holotype of Homoeusa laevigata Sharp, 1888, male; B. The lectotype of Homoeusa japonica Sharp, 1874, male; C. The holotype of Homoeusa longicornis Sharp, 1888, male; D, E. The labels pinned with each specimen (all photographed by Keita Matsumoto). dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 530 Figure 3. Habiti of Japanese Homoeusa spp. A. Homoeusa translucida sp. nov., holotype, male; B. Homoeusa laevigata Sharp, 1888, male from Nagano-ken; C. Homoeusa japonica Sharp, 1874, male from Fukuoka-ken; D. Homoeusa longicornis Sharp, 1888, male from Hokkaido; E. Homoeusa prolongata Sawada, 1970b, male from Nagano-ken; F. Homoeusa gigantea sp. nov., holotype, male; G. Homoeusa brevitarsis sp. nov., holotype, male. Additional material. Japan: Honshu: Ibaraki-ken • 2 exs.; Asahi-tôge, Tsuchiura-shi; 8.V.2022; Y. Komatsuzaki leg. (KUM) • 1 ex.; Nagai, Tsuchiura-shi; 27.IV.2022; Y. Komatsuzaki leg. (KUM). Chiba-ken • 5 exs.; Shimin-nomori Yachô-no-mori, Toyooka, Futtsu-shi; 10.V.2007; H. Ono leg. (KUM). Tokyo-to • 1 ex.; Mt. Takao (alt. 450 m), Hachiôji-shi; 4.VI.2001; M. Maruyama leg. LFS (NHM). Kanagawa-ken • 1 ex.; Nonkendainomori, Enkaizan, Yokohama-shi; 3.V.1991; K. Kubo leg. (SPMN). Nagano-ken • 2 exs.; Fuji, Satoyamabe, Matsumoto-shi; 21.V.2004; T. Komatsu leg. (KUM) • 1 ex.; Fuji, Satoyamabe, Matsumoto-shi; 9.VI.2004; T. Komatsu leg. (KUM). Gifu-ken • 3 exs.; Mitahora, Gifu-shi, 10.VI.2013; K. Kinomura leg. (KUM) • 2 exs.; Hirugano Bunsuirei Park, Gujo-shi; 10.VI.2013; K. Kinomura leg. (KUM). Shizuoka-ken • 2 exs.; Kumazaka, Izu-shi, Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 531 Figure 4. Homoeusa translucida sp. nov. A. Antenna; B. Pronotum and elytra; C. Zoomed view of elytron; D. Mesoand metaventrite; E, F. Posterior margin of 8th sternite; E. Male; F. Female; G. Median lobe of aedeagus from lateral view; H. Paramere of aedeagus from lateral view; I. Spermatheca. 30.V.2022; T. Tenma leg. (KUM). Aichi-ken • 1 ex.; Jôkôji-kôen, Seto-shi; 4.V.2023; T. Tenma leg. (KUM). Osaka-fu • 3 exs.; Sakurai [34.8828, 135.6525], Shimamoto-chô; 9.V.2021; Y. Takatani leg. LFS (KUM). Shikoku: Kagawa-ken • 1 ex.; Shirahige-jinja, Ayagami-chô; 25.IV.2004; H. Fujimoto leg. LFM (KUM). Kochi-ken • 2 exs.; Ashizuri-misaki (alt. 120 m) [32.7480, 133.0136], Tosashimizu-shi; 21.V.2024; TS. Nozaki leg. (KUM). Kyushu: Fukuoka-ken • 2 exs.; Bio. Exp. Center of Kyushu Univ., Mt. Hikosan, Soeda-machi; 24.IV.2021; N. Tsuji leg. (KUM) • 1♂; Biol. Lab. KU, Hikosan (alt. 750 m), Soeda-machi; 22.V.2011; M. Maruyama & T. Kanao leg. (KUM). Miyazaki-ken • 1 ex.; Ômoridake forest road (alt. 600 m) [32.0435, 131.1973], Aya-machi; 12.VI.2024; TS. Nozaki & T. Kinoda leg. LFS (KUM). Diagnosis. See Nozaki and Maruyama (2022a). Additional description. Relative length of each antennal segment from first to 11th, 2.27: 1.63: 1.37: 1.27: 1.02: 1.02: 1.00: 1.05: 1.07: 1.44: 3.34. Hind wings developed. Male. 8th sternite (Fig. 6A) weakly round at posterior margin; four setae of parameral apical lobe (Fig. 6C) normally arranged. dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 532 Figure 5. Homoeusa translucida sp. nov. A. Distribution map; black star – the type locality; white circles – collection data examined in this paper; B. A photograph of a living adult collected with Lasius meridionalis at Mt. Hikosan, Fukuoka-ken, Kyushu. Figure 6. Homoeusa rufescens (Sharp, 1874) and Homoeusa ovata Nozaki & Maruyama, 2022b. A–C, G. Homoeusa rufescens; D–F, H. Homoeusa ovata. A, B, D, E. Posterior margin of 8th sternite; A, D. Male; B, E. Female; C, F. Parameral apical lobe (modified from figs 13, 24 in Nozaki and Maruyama 2022a); G, H. Distribution map; black star – the type locality; white circles – collection data examined in Nozaki and Maruyama (2022a); black circles – additional data examined in this paper. Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 533 Female. 8th sternite (Fig. 6B) gently round at posterior margin. Distribution. Japan (Honshu, Shikoku, Kyushu) (Fig. 6G). Symbiotic hosts. Lasius cf. fuliginosus, L. morishitai, L. nipponensis, L. spathepus. Homoeusa ovata Nozaki & Maruyama, 2022 Fig. 6D–F, H (Japanese name: Hime-hirata-ariyadori) Homoeusa ovata Nozaki and Maruyama 2022b: 1 (provideing depository); Nozaki and Maruyama 2022a: 48 (detailed description but unavailable). “Homoeusa sp.:” Maruyama et al. 2013: 24 (distribution and bionomics mentioned). Additional material from Japan. Hokkaido • 1 ex.; Mt. Moiwa (alt. 520 m), Sapporo-shi; 27.VII.1991; A. Smetana leg. (NMST, ex A. Smetana coll.) • 5 exs.; Memanbetsu, Ôzora-chô; 7.VIII.2018; Y. Yoshimura leg. LFcfF (KUM). Honshu: Aomori-ken • 1 ex.; Yokonagare-tôge (alt. 300 m) [41.264, 141.314], Higashidori-mura; 26.VI.2023; TS. Nozaki leg. (KUM). Iwate-ken • 8 exs.; Gandô-ko, Morioka-shi; 9.VI.2019; N. Nakaya leg. LFcfF (IPMM) • 1 ex.; Kitayama-sansakuro, Morioka-shi; 31.VII.2019; N. Nakaya leg. LFcfF (IPMM). Yamagata-ken • 1 ex.; Senjuin, Yamadera (alt. 300–320 m) [38.319, 140.448]; Yamagata-shi; 15.VII.2024; K. Mizota leg. LFcfF (KUM). Ibaraki-ken • 2 exs.; Asahi-tôge, Tsuchiura-shi; 8.V.2022; Y. Komatsuzaki leg. (KUM). Saitama-ken • 1 ex.; Ushidatekubo (alt. 830 m) [35.9685, 139.1793], Tokigawa-machi; 21.V.2023; S.T. (Shota) Inoue & N. Katsube leg. LFcfF (KUM). Kanagawa-ken • 1 ex.; Kowakien, Mt. Hakone, Hakone-chô; 22.V.1963; R. Kiryu leg. (SCM) • 1 ex.; Toya, Tsukui, Sagamihara-shi; 11.IV.1976; R. Kiryu leg. (SCM) • 2 exs.; Nanzawa, Tsukui, Sagamihara-shi; 14.IV.1977; R. Kiryu leg. (SCM). Niigata-ken • 2 exs.; Sado Daira Ski Resort, Shinbo, Kanai (alt. 390 m) [38.076, 138.350], Sado-shi; 19.VI.2023; TS. Nozaki & W.R. Liang leg. LFN (KUM) • 1 ex.; Sado Daira Ski Resort, Shinbo, Kanai (alt. 380 m) [38.075, 138.350], Sado-shi; 20.VI.2023; TS. Nozaki & W.R. Liang leg. LFO (KUM) • 2 exs.; Sado Daira Ski Resort, Shinbo, Kanai (alt. 380 m) [38.075, 138.355], Sado-shi; 20.VI.2023; TS. Nozaki & W.R. Liang leg. LFcfF (KUM). Nagano-ken • 1 ex.; Bôdaira, Shiga-kôgen (alt. 1,160 m) [36.7203, 138.4656], Yamanouchi-machi; 9.VII.2022; TS. Nozaki leg. LFM (KUM) • 2 exs.; Satoyamabe [36.2457, 138.0096], Matsumoto-shi; 12.V.2021; TS. Nozaki leg. LFN (KUM). Gifu-ken • 2 exs.; Mt. Kentô, Takayama-shi; 6.VII.2003; K. Kinomura leg. (KUM) • 2 exs.; Bijo Pass, Takayama-shi; 5.VIII.2003; K. Kinomura leg. (KUM) • 1 ex.; Isshiki, Takayama-shi; 23.V.2004; K. Kinomura leg. (KUM) • 1 ex.; Nabedaira-kôgen, Takayama-shi; 30.VI.2013; K. Kinomura leg. (KUM) • 2 exs.; Hirugano Bunsuirei Park, Gujo-shi; 10.VI.2013; K. Kinomura leg. (KUM) • 1 ex.; Yôrô Park, Yôrô-chô; 29.IV.2004; K. Kinomura leg. (KUM) • 2 exs.; Mitahora, Gifu-shi; 10.VI.2013; K. Kinomura leg. (KUM). Shizuoka-ken • 2 exs.; Kumazaka, Izu-shi; 30.V.2022; T. Tenma leg. (KUM). Aichi-fu • 2 exs.; Jôkôji-kôen, Seto-shi, 4.V.2023; T. Tenma leg. (KUM). Osaka-fu • 3 exs.; Sakurai [34.8828, 135.6525], Shimamoto-chô; 9.V.2021; Y. Takatani leg. LFS (KUM). Shikoku: Kochi-ken • 1 ex.; Ashizuri-misaki (alt. 120 m) [32.7480, 133.0136], Tosashimizu-shi; 21.V.2024; TS. Nozaki leg. (KUM). Kyushu: Miyazaki-ken • 1 ex.; Ômoridake forest road (alt. 600 m) [32.0435, 131.1973], Aya-machi; 12.VI.2024; TS. Nozaki & T. Kinoda leg. LFS (KUM). Diagnosis. See Nozaki and Maruyama (2022a). Additional description. Relative length of each antennal segment from first to 11th, 2.31: 1.98: 1.48: 1.29: 1.17: 1.00: 1.14: 1.14: 1.26: 1.4: 3.36. Hindwings developed. Male. 8th sternite (Fig. 6D) gently round at posterior margin; apical lobe of paramere (Fig. 6F), setae b and c irregularly distributed at the acute corner on dorsal side. Female. 8th sternite (Fig. 6E) gently round at posterior margin. Distribution. Russia (Primorskyi krai), Korea, Japan (Hokkaido, Honshu, Shikoku, Kyushu) (Fig. 6H). Symbiotic hosts. Lasius fuji, L. cf. fuliginosus, Lasius morisitai, L. nipponensis, L. orientalis, L. spathepus. Homoeusa laevigata Sharp, 1888 Figs 2A, D, 3B, 7A–I, 8A–H (Japanese name: Tsuya-hirata-ariyadori) Homoeusa laevigata Sharp, 1888: 283 (original description); Schülke and Smetana 2015; 682 (catalogue); Maruyama et al. 2013: 24 (distribution and bionomics mentioned). Type material. Holotype (Fig. 2A, D) • ♂; “Homoeusa” / “laevigata” / “Type” / “D.S.” (written on the card which the specimen mounted) // “Seba” / “30.y.’81.” // “Type” (red round curator label) // “HOLOTYPE” / “Homoeusa” / “laevigata” / “SHARP, 1888” / “det. MARUYAMA, 2003” // “NHMUK014379778” (dissected by MM) (NHM). Additional material examined. Japan: Honshu: Miyagi-ken • 2 exs.; Aoba-yama, Sendai-shi; 10.VII.2004; K. Mizota leg. LFN (KUM) • 3♂♂, 1♀, 7 exs.; same locality; 17.VII.2004 K. Mizota leg. LFN (KUM) • 2♂♂; Aoba Forest Greenery [38.2577, 140.8255], Sendai-shi; 12.VIII.2024; TS. Nozaki leg. LFN (KUM). Fukushima-ken • 2♀♀; Kuraizaka-toge, Nishiaizu-machi; 18.VI.2022; K. Haga leg. LFN (KUM) • 1♂; Ueda dam, Kaneyama-machi; 25.VI.2023; K. Haga leg. LFN (KUM). Ibaraki-ken • 1♂, 1 ex.; Mt. Yamizo, Daigo-machi; 4.V.2022; Y. Komatsuzaki leg. (KUM). Saitama-ken • 1 ex.; Hashidate riv. (alt. 500 m), Chichibu-shi; 17.VII.1999; K. Toyoda leg. LFN (KUM) • 2♂♂, 1♀, 3 exs.; Hashidate, Chichibu-shi; 17.VII.1999; K. Toyoda leg. LFN (KUM) • 2♂♂, 1♀, 12 exs.; same locality; dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 540 Thorax. Pronotum (Fig. 9C) subrectangular, transverse (PW/PL, 1.59–1.71), widest near middle, postero-lateral angle around 90 degrees, posterior margin slightly sinuate, reddish yellow to reddish brown, surface finely covered with setae and punctures, gently polished and slightly reticulated. Elytra (Fig. 9C, D) distinctly widened posteriad entirely, posterior margins shallowly notched near lateral corners, reddish yellow to reddish brown, surface finely covered with setae and punctures; gently polished and weakly reticulated. Hind wings developed. Mesoventral process (Fig. 9E) very narrow, with weak medial carina, forming Y-shaped, apex sharply pointed, reaching posterior 1/3 of mesocoxal cavities. Metaventral process weakly produced. Abdomen elongate, narrowed posteriad; surface covered with short setae and each posterior margin with long stout setae; finely reticulated. Male: 8th sternite (Fig. 9F) rounded at posterior margin; median lobe of aedeagus (Fig. 9H) slender, length about 0.55 mm, apical lobe narrow and elongate, slightly curved dorsally, apex gently pointed in lateral view, apical valves simple and elongate, without dorsal arms, basal part of copulatory piece very small. Paramere (Fig. 9I, J) length about 0.65 mm; apical lobe of paramere very long, length about half of whole paramere, curved ventrally, slightly dilated apicad, apex simply round; four setae, a far longer than others, b located most apically, velum short and suboval. Female: 8th sternite (Fig. 9G) truncated or slightly rounded at posterior margin; spermatheca (Fig. 9K, L) S-shaped, base of apical part not swollen, base largely hooklike. Variations. Geographical variations were found in the parameral apical lobe. The populations from Chugoku, Shikoku, and Kyushu had a less curved apical lobe, with a finely dentate dorsal margin (Figs 9I, 10A), whereas the population from the eastern part of Honshu had a more curved apical lobe with a smooth dorsal margin (Figs 9J, 10 B–D). The distribution of each population is shown in Fig. 10E. Measurements (in mm) and ratios. Body parts (N = 19): BL ≈ 2.14–3.27; AL, 0.81–1.03; HW, 0.51–0.66; PL, 0.48–0.63; PW, 0.78–1.03; EL, 0.42–0.51; EW, 0.85– 1.02; HTL, 0.52–0.67; PW/PL, 1.59–1.71; AL/PL, 1.36– 1.86; HTL/PL, 0.94–1.15. Distribution. Japan (Honshu, Shikoku, Kyushu) (Fig. 10E). Symbiotic hosts. Lasius fuliginosus species group: L. cf. fuliginosus, L. morisitai, L. nipponensis, L. orientalis, L. spathepus. Bionomics. Homoeusa japonica can be observed in Lasius fuliginosus species group foraging trails on the forest floor from April to August (Fig. 10F). Only a few individuals were collected using FIT (N = 7). They frequently raised the tip of their abdomen toward approaching host ant workers, both in the field and indoors (Fig. 10G). Remarks. According to the original description (Sharp 1874), the type locality was assumed to be Nagasaki City, Nagasaki Prefecture, Kyushu. This species was rarely collected from the trails of L. nipponensis and L. orientalis. The differences in the parameres between the two populations were significant; however, no other differences were found. They may have been distributed separately because they were never collected from the same locality. We conclude that they can be reasonably treated as intraspecific populations. This species tends to occur at lower altitudes than H. longicornis does. Homoeusa longicornis Sharp, 1888 Figs 2C, F, 3D, 11A–K, 12A–F (Japanese name: Higenaga-hirata-ariyadori) Homoeusa longicornis Sharp, 1888: 283 (original description); Schülke and Smetana 2015; 682 (catalogue); Maruyama et al. 2013: 25 (distribution and bionomics mentioned). Type material. Holotype (Fig. 2C, F) • ♂; “Homoeusa” / “longicornis” / “D.S. Type” (written on the card which the specimen mounted) // “Japan.” / “G. Lewis.” / “1910–320” // “Sapporo.” / “5.VIII.–16.VIII.80.” // “Type” (red round curator label) // “HOLOTYPE” / “Homoeusa” / “longicornis” / “SHARP, 1888” / “det. MARUYAMA, 2003” // “NHMUK014379776” (dissected by MM) (NHM). Additional material examined. Japan: Hokkaido • 2 exs.; Hebinuma, Teshio-gawa, Teshio-chô; 9.VII.1992; S. Hori leg. (KUM) • 2♂♂; Mukôengaru, Engaru-chô; 25.V.2000; Y. Kida leg. (KUM) • 3 exs.; Kanayama, Makoi, Shari-chô; 24.VI.2002; Y. Kida leg. (KUM) • 3 exs.; Taihei, Maruseppu, Engaru-chô; 28.V.2000; Y. Kida leg. LFcfF (KUM) • 22 exs.; same locality; 29–31.V.2000; Y. Kida leg. LFcfF (KUM) • 11 exs.; same locality; 2–3. VI.2000; Y. Kida leg. LFcfF (KUM) • 1 ex.; same locality; 13.VI.2000; Y. Kida leg. (KUM) • 6♂♂, 5♀♀, 288 exs.; same locality; 16–17.VI.2000; Y. Kida leg. LFcfF (KUM) • 1♂, 7 exs.; same locality; 19–21.VIII.2000; Y. Kida leg. LFcfF (KUM) • 2♂♂, 1♀, 17 exs.; same locality; 25.VIII.2000; Y. Kida leg. LFcfF (KUM) • 1 ex.; Memanbetsu, Ôzora-chô; 7.VIII.2018; Y. Yoshimura leg. LFcfF (KUM) • 1 ex.; Kashiwa-gaoka-kôen, Bihoro-chô, 23.VI.2000; Y. Yamaga leg. (KUM) • 1 ex.; Mitomi-shizenkôen, Bihoro-chô; 13.VI.2000; Y. Yamaga leg. (KUM) • 2 exs.; Attoko, Nemuro-shi; 30.VI.1996; Y. Hirama leg. (KUM) • 5 exs.; Ôsawaguchi, Nopporo-shinrin-kôen, Ebetsu-shi; 2.VI.1999; M. Maruyama leg. (KUM) • 26 exs.; Ôsawaguchi, Nopporo-shizenkôen, Ebetsu-shi; 16–19. VI.2001; S. Hori leg. (KUM) • 2 exs.; Mt. Maruyama, Sapporo-shi; 6.VI.1998; M. Maruyama leg. (KUM) • 2 exs.; Tomanbetsu, Nopporo, Ebetsu-shi; 29.V.2002; M. Maruyama leg. LFcfF (KUM) • 2 exs.; Shibumbersu, Nopporo-shinrin-kôen, Ebetsu-shi; 11.V.2000; M. Maruyama leg. LFcfF (KUM) • 1 ex.; Mt. Moiwa, Sapporo-shi, 16.VI.1983; Y. Hirano leg. (KUM) • 10 exs.; Hitsujigaoka, Sapporo-shi; 18.V.2000; M. Maruyama leg. LFS (KUM) • 24 exs.; Kannon-zawa, Sapporo-shi; 1.VI.2002; M. Maruyama leg. LFcfF (KUM) • 1♂, 2♀♀, 24 exs.; same locality; 31.VI.2002; M. Maruyama leg. LFcfF (KUM) • 2 exs.; Hyakumatsuzawa, Sapporo-shi; 8.VI.1998; M. Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 541 Maruyama leg. LFcfF (KUM) • 4 exs.; Hakken-zan, Sapporo-shi; 31.V.2002; M. Maruyama leg. LFcfF & LU (KUM) • 3 exs.; same locality; 1.VI.2002; M. Maruyama leg. LFcfF & LU (KUM) • 1 ex.; Yûtoku, Ôtaki-mura, Date-shi; 24.VIII.2001; M. Maruyama leg. (KUM). Honshu: Aomori-ken • 1 ex.; Yokonagare-tôge (alt. 300 m) [41.264, 141.314], Higashidori-mura; 26.VI.2023; TS. Nozaki leg. LFcfF (KUM) • 1♂, 1♀, 1 ex.; Kuromori (alt. 280 m) [40.677, 140.191], Ajigasawa-machi; 24.VI.2023; TS. Nozaki leg. LFcfF (KUM) • 1♀; Yunosawa, Tokiwano (alt. 490 m) [40.633, 140.268], Hirosaki-shi; 25.VI.2023; TS. Nozaki leg. LFcfF (KUM). Miyagi-ken • 1♀; Toriido-yama, Komono-chô; 2.VI.2012; N. Tsuji leg. (KUM). Yamagata-ken • 1♂, 1 ex.; Senjuin, Yamadera (alt. 300– 320 m) [38.319, 140.448], Yamagata-shi; 15.VII.2024; K. Mizota leg. LFcfF (KUM). Fukushima-ken • 4 exs.; Kashi Spa., Nishigo-mura; 16.VI.1998; M. Maruyama leg. LFcfF (KUM) • 1♀, 3 exs.; same locality; 17.VI.1998; M. Maruyama leg. LFcfF (KUM) • 1 ex.; Yukiwari-bashi, Nishigo-mura; 29.VII.2000; M. Maruyama leg. (KUM). Ibaraki-ken • 1 ex.; Sadanami, Sekimoto-chô, Kitaibaraki-shi; 4.V.2022; Y. Komatsuzaki leg. (KUM). Gunma-ken • 1 ex.; Tanigawa Spa, Minakami-chô; 7.VI.2001; T. Watanabe leg. (KUM) • 1 ex.; Near Shima, Nakanojo-machi; 12.VI.1986; T. Katsumoto leg. (SCM) • 2♂♂, 1♀, 4 exs.; Nakanojo Forest Park, Nakanojo-machi; 8.VI.2001; T. Watanabe leg. (KUM) • 10 exs.; Sakurayama Park, Onishi, Fujioka-shi; 9.V.1998; Shiho Arai leg. LFS (KUM) • 4 exs.; Mt. Sakurayama, Onishi, Fujioka-shi; 9.V.1998; K. Toyoda leg. LFS (KUM) • 3 exs.; same locality; 18.V.1998; K. Toyoda leg. LFS (KUM) • 2♂♂, 3♀♀, 3 exs.; same locality; 22.V.1999; Shiho Arai leg. LFS (KUM) • 1 ex.; Shiozawa-toge, Fujioka-shi, 6.IX.2001; T. Watanabe leg. (KUM). Saitama-ken • 1 ex.; Mt. Sakurayama, Onishi; 2.V.2009; K. Arai leg. (KUM) • 2 exs.; Mt. Kamafuse yama, Fu-uppu (alt. 570 m), Yorii-machi; 22.IV.2006; K. Arai leg. LFcfF (KUM) • 1 ex.; Chichibu-kôgen, Higashichichibu-mura; 3.VII.1999; K. Toyoda leg. (KUM) • 6 exs.; Kasayama Sancho, Koshigoe, Ogawa-machi; 30.IV.2005; K. Arai leg. LFS (KUM) • 2 exs.; Karibazaka Pass [35.9683, 139.1816], Tokigawa-machi; 24.V.2022; TS. Nozaki leg. LFcfF (KUM) • 2 exs.; Hashidate, Chichibu-shi; 26.IV.1998; K. Toyoda leg. LFS (KUM) • 1 ex.; same locality; 26.IV.1998; S. Arai leg. (KUM) • 3 exs.; same locality; 7.VI.2002; K. Toyoda leg. LFM (KUM) • 1 ex.; Koakazawa, Irikawa, Mt. Hakutai-san, Ootaki (alt. 1,100 m), Chichibu-shi; 7–8.VI.2008; K. Arai leg. (KUM). Tokyo-to • 4 exs.; Mt.Takao, Hachiôji-shi; 1.V.1985; S. Kubota leg. (KUM) • 2 exs.; Mt.Takaozan, Hachiôji-shi; 26.IV.1986; A. Izumi leg. LFS (KUM) • 2 exs.; Mt. Takao, Hachiôji-shi; 1.VII.1998; M. Maruyama leg. LFS (KUM) • 1 ex.; same locality; 4.VII.1998; M. Maruyama leg. LFS (KUM) • 1 ex.; Mt. Takao (alt. 500 m), Hachiôji-shi; 1–4.VII.1998; M. Maruyama leg. (KUM) • 1♂, 1♀, 12 exs.; Mt. Takao (alt. 450 m), Hachiôji-shi; 4.VI.2001; M. Maruyama leg. (KUM) • 1♂, 1 ex.; same locality, Hachiôji-shi; 4.VI.2001; M. Maruyama leg. LFS (NHM). Kanagawa-ken • 2 exs.; Hokizawa, Nishi-tanzawa; 25–26.VI.1983; Y. Hirano leg. (KUM) • 1 ex.; Minami-Ashigara-shi; 11.II.1975; Y. Hirano leg. (KUM) • 2 exs.; Mt. Daiyûzan, Minami-Ashigara-shi; 28.VI.1987; A. Izumi leg. LFcfF (KUM) • 1 ex.; Daiyuzan, Hakone; 26.V.1986; Y. Shibata leg. (KUM) • 1 ex.; Daiyuzan, Ashigara; 21.V.1989; Y. Shibata leg. (KUM) • 2 exs.; Hakone; 4.V.1987; M. Tao leg. (KUM). Niigata-ken • 1 ex.; Ochinomizu, Tokamachi-shi; 19.IV.1998; T. Kishimoto leg. LFcfF (KUM) • 1 ex.; Foot of Mt. Uedafuji, Yuzawa-machi; 18.IV.1998; H. Yoshitomi leg. (KUM) • 1 ex.; Yuzawa-machi; 20–22.VI.2002; S. Nagashima leg. LFcfF (KUM). Yamanashi-ken • 1♂; Gozaishi-kôsen (alt. 900 m), Nirasaki-shi; 25.VII.2002; S. Nomura leg. LFN (KUM) • 3 exs.; Ashiyu-onsen, Ashiyu-mura; 23.V.2001; T. Watanabe leg. (KUM) • 1 ex.; same locality; 24.V.2001; T. Watanabe leg. (KUM). Nagano-ken • 1 ex.; Midarebashi, Chikuhoku-mura; 21.VII.1999; T. Watanabe leg. (KUM) • 1♂, 1 ex.; Ôkubo, Komoro-shi; 29–30.IV.2001; H. Kamezawa leg. LFcfF (cKam). Gifu-ken • 2♂♂; Bijo Pass, Takayama-shi; 5.VIII.2003; K. Kinomura leg. (KUM) • 1♂, 1 ex.; Hirugano Bunsuirei Park, Gujo-shi; 10.VI.2013; K. Kinomura leg. (KUM) • 1♂; Mt. Kentô, Takayama-shi; 6.VII.2003; K. Kinomura leg. (KUM) • 2♂♂; Yôrô Park, Yôrô-chô; 29.IV.2004; K. Kinomura leg. (KUM). Shizuoka-ken • 2 exs.; Utsuno, Fujinomiya; 30.V.2000; T. Watanabe leg. Fish feed Bait, pinned with a Phidole ant det. by K. Matuura (KUM). Aichi-ken • 1♀; Jôkôji-kôen, Seto-shi; 16.IV.2023; T. Tenma leg. (KUM). Kyoto-fu • 1♂, 1 ex.; Tenno-zan, Oyamazaki-chô; 16.IV.2008; T. Ito leg. (OMNH) • 2 exs.; same locality; 31.V.2008; T. Ito leg. (OMNH) • 1♀; Amagase Forest, Uji-shi; 8.V.2013; T. Ito leg. (OMNH) • 1 ex.; Otokoyama, Yawata-shi; 11.V.2014; T. Ito leg. (OMNH) • 1♂; same locality; 14.VI.2008; T. Ito leg. (OMNH). Osaka-fu • 1♂; Mt. Mikusa, Nosechô; 21.VI.2008; T. Ito leg. (OMNH) • 1♂; Mino-o Park, Mino-shi; 28.V.2008; T. Ito leg. (OMNH). Hyogo-ken • 2♂♂, 1♀, 1 ex.; Dojo, Kobe-shi; 13.IV.2009; T. Ito leg. (OMNH). Nara-ken • 1♀; Yamato-Koriyama, Yata; 9.VII.2009; T. Ito leg. (OMNH) • 1♂; same locality; 18.V.2009; T. Ito leg. (OMNH). Wakayama-ken • 1♂; Kimitoge Pass, Hashimoto-shi; 1.VI.2009; T. Ito leg. (OMNH) • 1♂; same locality; 27.IV.2014; T. Ito leg. (OMNH). Tottori-ken • 1 ex.; Mt. Daisen, Daisen-chô; 3–5.VI.1980; S. Naomi leg. (KUM). Shimane-ken • 1♂; Urahikimi, Masuda-shi, Masuda-shi; 6.VI.1998; S. Nomura leg. LFS (KUM). Hiroshima-ken • 1♂; Mt. Iwahi (alt. 1,110 m) [35.0712, 133.2192], Shobara-shi; 16.VI.2024; TS. Nozaki leg. LFcfF (KUM). Shikoku: Tokushima-ken • 2 exs.; Takashiro-yama, Naka-chô; 24.V.2007; H. Fujimoto leg. LFS (KUM). Kagawa-ken • 1 ex.; Ôtawa, Nagao, Sanuki-shi; 22.V.2000; F. Ito leg. (KUM) • 2 exs.; Daisen-zan, Kotonami-chô; 1.VI.2001; M. Maruyama et al. leg. LFN (KUM) • 1 ex.; same locality; 3.V.2004; H. Fujimoto leg. LFcfF (KUM). Ehime-ken • 1♂, 1♀; Mt. Ishiduchi, Saijo-shi; 29.VI.2014; Y. Hisasue leg. (KUM). Kochi-ken • 1♂, 1♀; Hokigamine (alt. 500 m) [33.6719, 133.6846], Kami-shi; 11.V.2023; TS. Nozaki leg. LFS (KUM). dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 542 Figure 11. Homoeusa longicornis Sharp, 1888. A, B. Antenna; A. Male; B. Female; C. Pronotum and elytra; D. Zoomed view of elytron; E. Mesoand metaventrite; F, G. Posterior margin of 8th sternite; F. Male; G. Female; H. Median lobe of aedeagus from lateral view; I. Paramere of aedeagus from lateral view; J, K. Spermatheca. Diagnosis. This species is distinguished from the other species of the genus by the following combination of characteristics: pronotal posterolateral angle around 90 degrees (Fig. 11C); elytra distinctly widened entirely posteriad (Fig. 11C, D); apical lobe of paramere very long, length over half of whole paramere, curved ventrally, apex blade-shaped (Fig. 11I). This species is quite similar to H. japonica in its general appearance but can be separated by the blade-like apex of its parameral apical lobe. Redescription. Body (Figs 3D, 12F) large, broad, stout; dorsal surface mostly moderately polished. Head large; color reddish brown to dark brown; eyes small. Antennae (Fig. 11A, B) very long. Thorax. Pronotum (Fig. 11C) subrectangular, transverse (PW/PL, 1.53–1.64), widest anterior 1/3, postero-lateral angle around 90 degrees, posterior margin slightly sinuate, reddish yellow to reddish brown, surface finely covered with setae and punctures, gently polished and slightly reticulated. Elytra (Fig. 11C, D) distinctly widened posteriad entirely, posterior margins shallowly notched near lateral corners, reddish yellow to reddish brown, surface finely covered with setae and punctures; Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 543 Figure 12. Homoeusa longicornis Sharp, 1888. A–C. Variations of aedeagi; A. Mt. Ishizuchi-san, Ehime-ken, Shikoku; B. Maruseppu-chô, Hokkaido; C. Nakanojo-shi, Gunma-ken; D. Distribution map; black star – the type locality (“Sapporo”); white circles – collection data examined in this paper; E. A walking adult in a foraging trail of Lasius cf. fuliginous on a fallen branch, Iimori-toge, Saitama-ken, Honshu; F. Clear image of living adult from Aomori-ken. gently polished and weakly reticulated. Hind wings developed. Mesoventral process (Fig. 11E) very narrow, with weak medial carina, forming Y-shaped, apex sharply pointed, reaching posterior 1/3 of mesocoxal cavities. Metaventral process weakly produced. Abdomen elongate, narrowed posteriad; surface covered with short setae and each posterior margin with long stout setae; finely reticulated. Male: Relative length of each antennal segment from first to 11th, 1.66: 1.13: 1.16: 1.07: 1.00: 1.04: 1.00: 1.06: 1.01: 1.13: 2.25. 8th sternite (Fig. 11F) weakly rounded at posterior margin; median lobe of aedeagus (Fig. 11H) slender, length about 0.63 mm, apical lobe elongated, ventral side slightly humped at middle, apex gently pointed in lateral view, apical valves simple and very long, without dorsal arms, basal part of the copulatory piece very small. Paramere (Fig. 11I) length about 0.79 mm; apical lobe of paramere extremely long, length over half of whole paramere, curved ventrally, dilated apicad, apex blade-shaped; four setae, a far longer than others, b located most apically, velum elongate, broad and produced apically. Female: Relative length of each antennal segment from first to 11th, 2.37: 1.57: 1.29: 1.09: 1.06: 1.00: 1.06: 1.08: 1.17: 1.40: 2.88. 8th sternite (Fig. 11G) truncated or slightly rounded at posterior margin; spermatheca (Fig. 11J, K) S-shaped, apex of basal part not swollen, base largely hooklike. Variation. Apical lobe of aedeagal median lobe varies on the degree of dorsally curve, intension of middle hump dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 544 ventral side, and depth of basal concave (Fig. 12A–C) independently of geographical locations. Measurements (in mm) and ratios. Body parts (N = 12): BL ≈ 2.58–3.54; AL, 0.98–1.3; HW, 0.59–0.7; PL, 0.59–0.72; PW, 0.97–1.13; EL, 0.5–0.59; EW, 0.94–1.13; HTL, 0.65–0.8; PW/PL, 1.53–1.64; AL/PL, 1.5–1.91; HTL/PL, 0.98–1.13. Differences between sexes: AL/PL (male, N = 5), 1.82– 1.91; AL/PL (female, N = 7), 1.5–1.65; HTL/PL (male, N = 5), 1.05–1.13; HTL/PL (female, N = 7), 0.98–1.04. Distribution. Japan (Hokkaido, Honshu, Shikoku) (Fig. 12D). Symbiotic hosts. Lasius fuliginosus species group: L. cf. fuliginosus, L. morisitai, L. nipponensis, L. orientalis, L. spathepus. Bionomics. Homoeusa longicornis can be observed in Lasius fuliginosus species group foraging trails on the forest floor from April to August (Fig. 12E). To the best of our knowledge, no individual was collected using FIT. The beetles were observed to be frequently raising the tip of their abdomen when approaching the host ant workers in the field and indoors. Remarks. This species is rarely collected from the trails of L. nipponensis and L. orientalis. This species is very similar to H. japonica in terms of its habitus (Fig. 12F) and bionomics. H. longicornis tends to occur at higher altitudes than that of H. japonica. However, both species frequently co-occur at moderate altitudes in Honshu and Shikoku, even within the same colony of host ants. Precisely distinguishing between the two species is challenging without examining male genitalia. The pronotum length can be helpful; that of H. longicornis is usually longer than 0.65 mm, whereas that of H. japonica is shorter than 0.65 mm, but some exceptions remain in both species. Homoeusa prolongata Sawada, 1970 Figs 3E, 13A–I, 14A–D (Japanese name: Hirata-ariyadori) Homoeusa prolongata Sawada, 1970b: 57, fig. 14 (original description); Schülke and Smetana 2015; 682 (catalogue); Maruyama et al. 2013: 26 (distribution and bionomics mentioned). Type material. Not examined. Additional material examined. Japan: Hokkaido • 2 exs.; Near Hime-numa, Oshidomariwannai (alt. 130 m), Rishiri-chô; 5.VI.2024; T. Yamauchi leg. (OUAVM) • 1 ex.; “Horokanai Butokamabetsu Riv” (alt. 300 m); 3. VIII.1991; A. Smetana leg. (NMST, ex A. Smetana coll.) • 1 ex.; Kanayama, Makoi, Shari-chô; 24.VI.2002; Y. Kida leg. (KUM) • 1♂, 1 ex.; Teine-yama [43.0836, 141.2024], Sapporo-shi; 23.V.2020; Y. Tasaku leg. (KUM) • 1♂; Ôsawaguchi, Nopporo-shizenkôen, Ebetsu-shi; 16–19.VI.2001; S. Hori leg. (KUM) • 2 exs.; Kannon-zawa, Sapporo-shi; 19.V.2021; Y. Tasaku leg. (KUM) • 2 exs.; Hakken-zan, Sapporo-shi; 1.VI.2002; M. Maruyama leg. (KUM) • 1♀; Mt. Kariba, Shiribeshi; 12.VI.1986; S. Nomura leg. (KUM). Honshu: Aomori-ken • 1 ex.; Iwaki river riverbed, Kawazura (alt. 10 m) [40.694, 140.455], Itayanagi-machi; 28.VI.2023; TS. Nozaki leg. LNS (KUM). Iwate-ken • 1♀, 1 ex.; Kitayama, Morioka-shi; 23.IV–3.V.2024; N. Nakaya leg. FIT (IPMM) • 1 ex.; Mt. Takabora, Kamiyonai, Morioka-shi; 21.IV–3.V.2024; N. Nakaya leg. FIT (IPMM). Akita-ken • 1 ex.; Kawara-bo, Mt. Hachimine, Hanamaki-shi; 22– 24.VI.1980; S. Naomi leg. (KUM). Fukushima-ken • 1 ex.; Zenjin, Mt. Chokai, Yurihonjo-shi; 19–20.VI.1980; S. Naomi leg. (KUM) • 1 ex.; Yokomuki, Mt. Adatara, Inawashiro-machi; 10.VII.1985; S. Nomura leg. (KUM) • 1 ex.; Kozodaira, Hinoemata-mura; 26.VII.1996; S. Naomi leg. (KUM) • 2 exs.; Nanairi, Hinoemata-mura; 24.VII.1990; T. Kishimoto leg. (KUM). Tochigi-ken • 1 ex.; Mt. Nasu; 3.VI.1994; S. Naomi leg. (KUM) • 2 exs.; Chuzenji, Nikko-shi; 28–30.VI.1982; S. Naomi leg. (KUM) • 1 ex.; same locality; 24.VII.1985; S. Nomura leg. (KUM) • 1 ex.; “Nikko N.P. Lake Chuzenjiko” (alt. 1,280 m); “14.VII.80” [1980]; A. & Z. Smetana leg. (NMST, ex A. Smetana coll.) • 1 ex.; “Nikko N.P. Senjugahara” (alt. 1400 m); “15.VII.80” [1980]; A. & Z. Smetana leg. (KUM, ex A. Smetana coll.) • 1 ex.; Nagaishi Forest Road, Ashikaga-shi; 27.V.1990; H. Ohkawa leg. (KUM) • 1♂; Watarase-yûsuichi, Fujioka-machi; 16. IV.2000; H. Ôkawa leg. (KUM). Gunma-ken • 1 ex.; Mikuni-tôge, Minakami-machi; 27.VI.1997; S. Naomi leg. (KUM) • 1 ex.; Hôshi-onsen, Minakami-machi; 26. VI.1997; S. Naomi leg. (KUM) • 1 ex.; Amemi-rindou, Minakami-machi; 4.V.1998; Shiho Arai leg. (KUM) • 1♂, 1 ex.; Sakurayama, Fujioka-shi; 9.V.1998; Shiho Arai leg. (KUM) • 1 ex.; same locality; 22.V.1999; K. Toyoda leg. LNH (KUM) • 1♀, 3 exs.; same locality; 22.V.1999; Shiho Arai leg. LNH (KUM) • 1 ex.; same locality; 27.V.2000; Shiho Arai leg. LNH (KUM). Saitama-ken • 1 ex.; Mt. Jômine-san, Minano-machi; 29.V.1999; Shiho Arai leg. LNH (KUM) • 1 ex.; Chichibu-kôgen, Higashichichibu-mura; 5.V.2000; Shiho Arai leg. (KUM) • 1 ex.; Sugaya, Ranzan-machi; 14.VI.1994; K. Toyoda leg. LNH (KUM) • 1 ex.; same locality; 16.VI.1994; K. Toyoda leg. (KUM) • 1 ex.; Iwadono, Higashimatsuyama-shi; 3.V.2005; K. Toyoda leg. LNJ (KUM) • 1 ex.; Near Tsumasaka-Toge, Hanno-shi; 20.VI.1998; K. Toyoda leg. (KUM) • 1♂; Kawaura-keikoku (alt. 600 m), Chichibu-shi; 20.VI.1998; Shiho Arai leg. (KUM) • 1♀; same locality; 27.VI.1998; Shiho Arai leg. (KUM) • 1 ex.; Kaminaguri, Hanno-shi; 23.V.1998; Shiho Arai leg. LNH (KUM) • 1 ex.; Sumiyairi-rindô, Hanno-shi; 3.VI.2000; Shiho Arai leg. LNH (KUM). Chiba-ken • 2 exs.; Ashida (alt. 10 m), Narita-shi; 17–25.VII.2014; R Nakamura leg. FIT (KUM) • 11 exs.; Okuno, Ichihara-shi; 12–14. VII.2000; S. Hatsushiba & T. Shimada leg. (KUM) • 1 ex.; same locality; 16–18.V.2001; S. Hatsushiba & T. Shimada leg. (KUM) • 1 ex.; same locality; 12–14.V.2001; S. Hatsushiba & T. Shimada leg. (KUM) • 1 ex.; Mt. Gundari, Ichinomiya-machi; 12.IV.1997; S. Nomura leg. (KUM) • 1 ex.; Umegase, Daifuku-yama, Ichihara-shi; Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 545 Figure 13. Homoeusa prolongata Sawada, 1970b. A. Antenna; B. Pronotum and elytra; C. Zoomed view of elytron; D. Mesoand metaventrite; E, F. Posterior margin of 8th sternite: E. Male; F. Female; G. Median lobe of aedeagus from lateral view; H. Paramere of aedeagus from lateral view; I, J. Spermatheca. 6.V.1998; S. Naomi leg. (KUM) • 1 ex.; Amatsu (alt. 70 m) [35.1406, 140.1512], Kamogawa-shi; 3.V.2016; S. Sejima leg. Litter (KUM). Tokyo-to • 1 ex.; Ônita, Ome-shi; 20.V.1991; T. Kishimoto leg. (KUM) • 1 ex.; Oyamada-chô, Machida-shi; 19.V.1992; T. Kishimoto leg. (KUM) • 1 ex.; Machida-shi; 28.V.1981; T. Niizato leg. (KUM). Kanagawa-ken • 3 exs.; Nanzawa, Tsukui, Sagamihara-shi; 6.V.1977; R. Kiryu leg. (SCM) • 1 ex.; Miyagase, Aikô; 19.IV.1977; R. Kiryu leg. (SCM) • 2 exs.; Kozukue, Yokohama-shi; 21.IV.1994; H. Sato leg. (KUM) • 1♂; Niiharutyô、Midori-ku [35.50, 139.51], Yokohama-shi; 25.IV.2012; O. Saitoh leg. (KPMNH) • 3 exs.; Trap St.1.Park / “Y.N.S”, Yokohama-shi; 8.VI.1988; Y. Kominami leg. (SPMN) • 1 ex.; Yakunimi-yama [35.35, 139.17], Hadano-shi; 27.VI.2014; O. Saitoh leg. (KPMNH) • 1 ex.; Kinugasa, Yokosuka-shi; 26–27. IV.1995; S. Tsuboyama leg. (KUM). Niigata-ken • 1♂; Kita-ikari (alt. 760 m) [38.1500, 138.4049], Sado-shi; 18.VI.2023; TS. Nozaki leg. (KUM) • 3 exs.; Mt. Tadara-mine, Ryotsu (alt. 810 m) [38.13, 138.38]; Sado-shi; 11.VI.2012; M. Yoshida leg. (KUM) • 2 exs.; Yokoyama, Sado-shi; 24–25.V.1995; T. Kishimoto leg. (KUM) • 1 ex.; Kaikake-onsen, Yuzawa-machi; 23.VI.1996; K. Haga leg. Leaf litter in Beech forest (KUM) • 1 ex.; Sasaga- dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 546 mine, Myoko-shi; 14–15.VI.1980; S. Naomi leg. (KUM) • 1 ex.; Suginosawa (alt. 950 m) [36.8519, 138.1399], Myoko-shi; 3.VI.2018; S. Sejima leg. Litter (KUM). Fukui-ken • 1 ex.; Mt. Houonji-san, Katsuyama-shi; 31.V.1989; Kouichi Matsumoto leg. (KUM) • 1 ex.; Mt. Gongen, Echizen-shi; 22.V.1981; H. Sasaji leg. (KUM). Yamanashi-ken • 1♀; Daibosatsu-rei [35.73, 138.82], Koshu-shi; 9.VI.2019; O. Saitoh leg. (KPMNH) • 1 ex.; Ryomata-goya, Noro-gawa riv., Minami-alps-shi; 3. VIII.1996; K. Haga leg. Fallen branch (KUM) • 5♂♂, 1♀, 2 exs.; Karumizu-rindo (alt. 1600 m), Narusawa-mura; 22–29.VI.2011; T. Watanabe leg. FIT (KUM) • 1 ex.; same locality; 29.VI–6.VII.2011; T. Watanabe leg. FIT (KUM) • 1 ex.; same locality; 27.VI–4.VII.2012; T. Watanabe leg. FIT (KUM) • 1 ex.; same locality; 25.VII–1. VIII.2012; T. Watanabe leg. FIT (KUM) • 2 exs.; Subashiri-guchi, Fujisan (alt. 1,400 m), Oyama-chô; 15– 20.V.2011; T. Watanabe leg. FIT (KUM) • 1 ex.; Subashiri, Fujisan 1-gome (alt. 1,400 m), Oyama-chô; 20–26.V.2011; T. Watanabe leg. FIT (KUM). Nagano-ken • 2 exs.; Shiga-kôgen (alt. 1,380 m) [36.728, 138.478], Yamanouchi-machi; 9.VII.2022; TS. Nozaki leg. Litter (KUM) • 1 ex.; same locality; 9.VII.2022; TS. Nozaki leg. LNH (KUM) • 1♂; Mizunashiike, Shiga-kôgen, Yamanouchi-machi; 9.VII.2022; TS. Nozaki leg. (KUM) • 1 ex.; Satoyamabe, Matsumoto-shi; 4.VI.2009; T. Komatsu leg. LNJ (KUM) • 1♂; Tobira, Matsumoto-shi; 5.VI.2011; M. Maruyama et al. leg. (KUM) • 1♀; Kohigashi, Chino-shi; 19.VI.2011; M. Maruyama et al. leg. (KUM) • 1♂; Kannon-daira, Yatsuga-take; 11. VII.2000; H. Hoshina leg. Beating (KUM). Shizuoka-ken • 1 ex.; Subashiri-guchi, Fujisan (alt. 1,400 m), Oyama-chô; 15–22.VI.2011; T. Watanabe leg. FIT (KUM) • 2 exs.; Hiekawa, Izu-shi; 2.VI.1983; T. Tahira leg. (KUM). Kyoto-fu • 1 ex.; Mt. Yôrô-san, Maizuru-shi; 25–26.V.2000; K. Mizuno leg. (KUM). Hyogo-ken • 1 ex.; Mt. Hyonosen; 5.VI.1984; S. Nomura leg. (KUM) • 1 ex.; Mt. Mimuro-yama; 7.VI.1997; H. Hoshina leg. (KUM). Nara-ken • 1 ex.; Nara; “11.VIII.80” [1980]; A. & Z. Smetana leg. (KUM, ex A. Smetana coll.) • 1 ex.; Nishitani, Yoshino-chô; 18–19.V.1995; Y. Nakahara leg. Bait trap (KUM) • 2 exs.; Mt. Nehan-dake (alt. 1,140 m), Shimokitayama-mura; 27.VI.1998; T. Kishimoto leg. (KUM). Wakayama-ken • 1 ex.; Hirai, Kozagawa-chô; 15.VIII.1999; M. Maruyama leg. LNJ (KUM) • 1 ex.; same locality; 16.VII.1999; M. Maruyama leg. LNN (KUM). Tottori-ken • 1 ex.; Hokidaisen, Daisen-chô; 3.VI.1980; S. Naomi leg. (KUM) • 3 exs.; Mt. Daisen, Daisen-chô; 3–5.VI.1980; S. Naomi leg. (KUM) • 2 exs.; Ônarubara-kôgen (alt. 770 m), Kôfu-chô; 18– 24.V.2008; A. Watanabe leg. FIT (KUM) • 3 exs.; same locality; 7–23.VI.2008; A. Watanabe leg. FIT (KUM) • 1 ex.; same locality; 24.V–1.VI.2008; A. Watanabe leg. FIT (KUM). Shimane-ken • 1♀; Dangyô-no-taki, Dôgo Is., Okinoshima-chô; 5–16.VI.2008; T. Shimada leg. (KUM). Okayama-ken • 1 ex.; Kanehira, Bicchu-chô (alt. 300 m), Takahashi-shi; 22.V–2.VI.2010; A. Watanabe leg. FIT (KUM) • 1 ex.; same locality, Takahashi-shi; 2–19. VI.2010; A. Watanabe leg. FIT (KUM). Hiroshima-ken • 1♂; Mt. Tate-eboshi (alt. 1,180 m) [35.0527, 133.0696], Shobara-shi; 15.VI.2024; TS. Nozaki leg. (KUM) • 1 ex.; Kakezu-yama, Higashiyawatahara (alt. 850–1,126 m), Kitahiroshima-chô; 30.IV–9.V.2009; TA. Nozaki & Y. Nozaki leg. FIT (KUM) • 2 exs.; same locality; 9–18.V.2009; TA. Nozaki & Y. Nozaki leg. FIT (KUM) • 1 ex.; same locality; 30.V–13.VI.2009; TA. Nozaki & Y. Nozaki leg. FIT (KUM) • 5 exs.; same locality; 13–27. VI.2009; TA. Nozaki & Y. Nozaki leg. FIT (KUM) • 1 ex.; same locality; 27.VI–4.VII.2009; TA. Nozaki & Y. Nozaki leg. FIT (KUM) • 1♂, 1 ex.; same locality; 4–18. VII.2009; TA. Nozaki & Y. Nozaki leg. FIT (KUM). Yamaguchi-ken • 1 ex.; Nodani, Tokuji-chô; 21.IV.2004; Y. Fujitani leg. (KUM). Shikoku: Tokushima-ken • 1 ex.; Meoto-ike, Tsurugi-chô; 30.VI.2006; H. Fujimoto leg. (KUM). Kagawa-ken • 2 exs.; Nagara-dam, Ayakami-chô; 5.V.2003; S. Nagashima leg. in litter (KUM) • 2 exs.; Shôzaka, Sogisho-higashi, Ayagawa-chô; 9–12. IV.2009; H. Fujimoto leg. FIT (KUM) • 1 ex.; same locality; 12–18.IV.2009; H. Fujimoto leg. FIT (KUM) • 1 ex.; same locality; 22–30.V.2009; H. Fujimoto leg. FIT (KUM) • 1 ex.; same locality; 25.IV–2.V.2010; H. Fujimoto leg. FIT (KUM). Kochi-ken • 1 ex.; Mt. Tsutsujô-zan (alt. 1,600 m), Ino-chô; 30.VI.2007; TA. (Takasuke) Miyata & TO. (Toshie) Miyata leg. (KUM) • 1 ex.; Ekawa, Nishitosa (alt. 120 m) [33.217, 131.784], Shimanto-shi; 12.V.2023; TS. Nozaki leg. (KUM). Kyushu: Fukuoka-ken • 1♂; Mt. Inunaki, Miyawaka-shi; 22.V.1980; T. Gotô leg. (KUM) • 1 ex.; Mt. Tachibana; 1.VI.1978; K. Yamagishi leg. (KUM) • 1 ex.; same locality; 5.V.1979; K. Yamagishi leg. (KUM) • 6 exs.; same locality; 10–14.V.1996; T. Ueno, Y. Higashiura & H. Goto leg. FIT (cSch) • 4 exs.; same locality; 15–17.V.1996; T. Ueno & H. Goto leg. FIT (cSch) • 1♀, 2 exs.; Mt. Shiouji-yama, Onojo-shi; 8.V.2013; K. Kido leg. FIT (KUM) • 1 ex.; same locality; 12.V.2013; K. Kido leg. FIT (KUM) • 1 ex.; same locality; 18.V.2013; K. Kido leg. FIT (KUM) • 2 exs.; Mt. Hikosan; 13.VI.1966; K. Takeno leg. (KUM) • 1♂, 1♀, 4 exs.; Seinen-no-ie, Hikosan (alt. 800 m), Soeda-machi; 22.V.2011; M. Maruyama & T. Kanao leg. LNJ (KUM) • 2 exs.; Kusenbu-yama; 24.V.2014; K. Kido leg. FIT (KUM) • 1 ex.; Mt. Miyomizu-yama, Miyama-shi; 16.V.1997; T. Ishikawa leg. (KUM). Saga-ken • 1♂; Mt. Ten-zan (alt. 1040 m) [33.339, 130.143], Karatsu-shi; 29.VI.2022; S.T. Inoue & Y. Hisasue leg. LNJ (KUM) • 1 ex.; Mt. Tenzan (alt. 1,000 m) [33.340, 130.142], Saga-shi; 18.VI.2022; Y. Hisasue leg. (KUM) • 2 exs.; Kurinoki-tôge, Mt. Kunimi-yama; 15.V.2019; M. Nishida leg. FIT (KUM) • 1 ex.; Mt. Kurokami-yama, Arita-chô; 18.V.2018; M. Nishida leg. FIT (KUM) • 2 exs.; Mt. Mifune, Takeo-shi; 27.V.1984; S. Naomi leg. (KUM) • 1 ex.; Tosen-zan (alt. 350 m), Ureshino-shi; 19.V.1997; S. Nomura leg. (KUM) • 1 ex.; Tosenzan, Ureshino-shi; 20.V.2018; M. Nishida leg. FIT (KUM) • 2 exs.; Mt. Tara, Tara-chô; 29.IV.1985; S. Naomi leg. (KUM). Nagasaki-ken • 1♀; Mt. Mitake, Tsushima Is., Tsushima-shi; 31.V.1988; S. Nomura leg. (KUM) Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 547 Figure 14. Homoeusa prolongata Sawada, 1970b. A. Distribution map; black star – the type locality (“Shiga Hights”); white circles – collection data examined in this paper; B, C. Snapped images from videos shot indoors, adults raising abdomen to an ant; D. Clear image of a living adult from Nagano-ken. • 2 exs.; Tanuki-no-o, Ômura-shi; 8.V.2019; M. Nishida leg. FIT (KUM) • 1 ex.; Mt. Yake, Shimabara-shi; 21. IV.1977; Imasaka leg. (KUM). Oita-ken • 1 ex.; Mt. Takasaki-yama, Beppu-shi; 9.V.2013; T. Miyake leg. FIT (KUM). Kagoshima-ken • 1 ex.; Mt. Kurinodake, Kurino-chô; 29.VI.1995; S. Onoda leg. (SPMN) • 1♂; Nageishidaira, Yakushima Is. (alt. 1,825 m) [30.322, 130.512], Yakushima-chô; 18.VIII.2021; S. Inoue leg. (KUM). Diagnosis. This species is distinguished from other species of the genus by the following combination of characteristics: a slightly produced metaventral process (Fig. 13D), median lobe of aedeagus bulbous with a length of approximately 0.47 mm (Fig. 13G). This species is similar to H. ovata and H. japonica, but it can be distinguished by a more flattened and semicircular pronotum, less produced metaventral process, and a bulbous median lobe of the male aedeagus. Redescription. Body (Figs 3E, 14D) small, broad, somewhat limuloid; dorsal surface mostly moderately polished. Head large; color yellowish brown to dark brown; eyes large. Antennae (Fig. 13A) short; relative length of each antennal segment from first to 11th, 2.39: 1.78: 1.14: 1.17: 1.00: 1.01: 1.10: 1.15: 1.20: 1.45: 3.94. Thorax. Pronotum (Fig. 13B) semicircular, transverse (PW/PL, 1.51–1.65), widest at posterior 1/3, postero-lateral angle acute to around 90 degrees, posterior margin slightly sinuate, yellowish brown to dark brown, surface finely covered with setae and punctures, gently polished and slightly reticulated. Elytra (Fig. 13B, C) slightly widened posteriad, widest at posterior 1/3, then narrowed roundly, posterior margins deeply notched near lateral corners, yellowish brown to dark brown, surface finely covered with setae and punctures; gently polished and weakly reticulated. Hind wings developed. Mesoventral process (Fig. 13D) very narrow, with indistinct medial carina, apex sharply pointed, reaching almost anterior margin of mesocoxal cavities. Metaventral process slightly produced. Abdomen elongate, narrowed posteriad; surface sparsely covered with short setae and each posterior margin with long stout setae; finely reticulated. Male: 8th sternite (Fig. 13E) weakly produced and angled at postero-medial margin; median lobe of aedeagus (Fig. 13G) bulbous, length about 0.47 mm, apical lobe short and slightly curved ventrally, apex round in lateral view, apical valves elongate and mitten-shaped, dorsal arms short, basal part of copulatory piece large. Paramere (Fig. 13H) length about 0.47 mm; apical lobe of paramere long, length about 1/3 of whole paramere, curved ventrally; four setae, normally arranged, b located a bit more basally than c, velum small. Female: 8th sternite (Fig. 13F) weakly produced roundly postero-medial margin; spermatheca (Figs 13I, J) Sor C-shaped, apex of basal part slightly sinuate, base largely hooklike. Variation. Intraspecies variations are recognized in the apical lobe of the aedeagal median lobe. Some individuals have a small hump at the base of the ventral side and a slightly deeper basal concave. The length of the parameral apical lobe also varies slightly. Measurements (in mm) and ratios. Body parts (N = 13): BL ≈ 1.9–2.78; AL, 0.67–0.81; HW, 0.43–0.52; PL, 0.46–0.61; PW, 0.73–0.92; EL, 0.37–0.51; EW, 0.73– 0.98; HTL, 0.4–0.48; PW/PL, 1.51–1.65; AL/PL, 1.22– 1.53; HTL/PL, 0.8–0.9. Distribution. Japan (Hokkaido, Honshu, Shikoku, Kyushu) (Fig. 14A). Symbiotic hosts. Lasius niger species group: L. hayashi, L. japonicus, L. sakagamii, L. productus. dez.pensoft.net Tsubasa Nozaki & Munetoshi Maruyama: Taxonomy of Japanese species of Homoeusa Kraatz, 1856 548 Bionomics. This species was collected from the nests of host ants under stones and in decaying wood and leaf litter near the entrances to these colonies from April to August. Many individuals were collected using FIT (N = 69). Bait traps set near the nest entrances were also effective in collecting H. prolongata. During indoor observations, H. prolongata was frequently observed, raising the tip of its abdomen toward approaching host ant workers, and sometimes just stopping (Fig. 14B, C). Remarks. The type specimens are currently not available. Sawada (1970a, 1970b) described 25 aleocharine species from Shiga Heights, Nagano Prefecture, Honshu, including H. prolongata. According to Takuto Hashizume, who specializes in the taxonomy of homalotines and their relatives, he could not access these type specimens by contacting the National Museum of Nature and Science, Tsukuba (“National Science Museum Tokyo”), which is designated in papers as a deposit, or by searching the Osaka Museum of Natural History, Osaka, Japan. However, the original descriptions and drawings of H. prolongata are sufficiently informative for species-level taxonomy. Therefore, we conclude that a neotype designation is not necessary currently. Maruyama et al. (2013) reported that some individuals similar to H. prolongata were found in trails of the Lasius fuliginosus group. However, we did not find any specimens of H. prolongata mounted together with L. fuliginosus. H. ovata may have been misrecognized as H. prolongata because some individuals of H. ovata resemble H. prolongata in terms of body size and general habitus. Homoeusa gigantea Nozaki & Maruyama, sp. nov. https://zoobank.org/124F8B44-AD0B-4159-908C-483796557467 Figs 3F, 15A–I, 16A–E (Japanese name: Ô-hirata-ariyadori) “Oxypodini? sp.1”: Nishida 2019: 135, fig. 10 (recorded from Saga pref.). Material examined. Holotype (Fig. 3F) • 1♂; “[Japan]: Fukuoka-ken, Soeda- ” / “machi, Mt. Hikosan, Takasubaru” / “[33.4883, 130.9174], alt. 770” / “m, 24.VII.2022, Tsubasa”/ “ NOZAKI leg. LCH01.” / “添田町英彦山鷹 巣原” // “Lasius” / “umbratus (Nylander, 1846)” / “ア メイロケアリ” / det. Tsubasa NOZAKI 2025” (KUM). Paratype. Japan: Hokkaido • 1♀; Makoi, Shari-chô; 28.V.2000; Y. Kida leg. LUM (KUM) • 2♀♀; Tôro lakeside, Shibecha-chô; 28.VII.1986; S. Nomura leg. (KUM) • 2♀♀; Nopporo, Ebetsu-shi; 13–21.VI.2000; Shigehisa Hori leg. (KUM) • 1 ex.; Minaminosawa, Sapporo-shi; 16–23.V.2023; Y. Tasaku leg. FIT (HUM) • 1 ex.; Hakken-zan, Sapporo-shi; 31.V.2002; M. Maruyama leg. (KUM) • 1♂; same locality; 20.VII.2022; TS. Nozaki leg. LUU (KUM) • 1 ex.; Obihiro-no-mori (alt. 78 m) [42.8987, 143.1439], Obihiro-shi; 15.VII.2022; TS. Nozaki & H. Nozaki leg. LUU (KUM) • 1 ex.; Higashi-ônura, Nanaechô; 16.VI.1986; S. Nomura leg. (KUM). Honshu: Iwate-ken • 1♂, 1 ex.; Kitayama-sansakuro, Morioka-shi; 2.V.2020; N. Nakaya leg. LUU (IPMM) • 1 ex.; Kitayama, Morioka-shi; 23.IV–3.V.2024; N. Nakaya leg. FIT (IPMM) • 1 ex.; Mt. Takabora, Kamiyonai, Morioka-shi; 3.V.2024; N. Nakaya leg. FIT (IPMM). Gunma-ken • 1 ex.; Yubisogawa, Minakami-machi; 18.VI.2004; M. Yasaka leg. (KUM). Nagano-ken • 2 exs.; Odairahara, Horigane (alt. 1,100 m), Azumino-shi; 12.VII.1998; M. Maruyama leg. LUU (KUM) • 1 ex.; Fujii, Satoyamabe [36.2513, 137.3436], Matsumoto-shi; 13.V.2021; S.T. Inoue leg. LUU (KUM) • 1 ex.; Iriyamabe, Matsumoto-shi; 30.VI.2012; M. Maruyama leg. LUU (KUM) • 1 ex.; Fujimi (alt. 1,510 m) [35.904, 138.190], Fujimi-chô; 4.VI.2023; TS. Nozaki leg. LUM (KUM). Gifu-ken • 1♀; Nabedaira-kôgen, Takayama-shi; 6.VII.2022; TS. Nozaki leg. LUM (KUM) • 2♂♂, 1♀; Nakao (alt. 1,200 m), Takayama-shi; 5.VI.2005; K. Kinomura leg. LUM (KUM) • 1 ex.; Iwai (alt. 830 m) [36.1320, 137.3436], Takayama-shi; 7.VII.2022; TS. Nozaki leg. LUM (KUM) • 1 ex.; Iwase (alt. 850 m), Takayama-shi; 5.V.2005; K. Kinomura leg. LUU (KUM) • 1 ex.; same locality; 4.VI.2006; K. Kinomura leg. LUU (KUM). Nara-ken • 1♂; Wasamata-yama (alt. 1,140 m) [34.2184, 135.9862], Kamikitayama-mura; 14.VI.2023; TS. Nozaki leg. LUM (KUM). Okayama-ken • 1 ex.; Jabuchi-no-taki, Mt. Nagi-san (alt. 579 m) [35.1567, 134.1908]; Nagi-chô; 15.V.2022; Y. Senda leg. (EUMJ). Hiroshima-ken • 1 ex.; Kakezu-yama, Higashiyawatahara (alt. 850–1,126 m), Kitahiroshima-chô; 27.VI–4.VII.2009; TA (Tatsuya). Nozaki & Yoko Nozaki leg. FIT (KUM). Shikoku: Kochi-ken • 1 ex.; Irazu-keikoku, Tsuno-chô; 14.V.2005; TA. Miyata & TO. Miyata leg. (KUM). Kyushu: Fukuoka-ken • 2 exs.; Takasubaru, Mt. Hikosan [33.4883, 130.9174], Soeda-machi; 18.VI.2021; TS. Nozaki leg. LUU (KUM) • 1♀, 1 ex.; same locality; 26.VI.2021; TS. Nozaki leg. LUM (KUM) • 2♂♂; Biol. Lab. KU, Hikosan, (alt. 750 m) [33.4806, 130.9090], Soeda-machi; 26.V.2021; TS. Nozaki leg. LUU (KUM) • 1 ex.; Zuibai-ji, Itoshima-shi; 8.V.2021; T. Hashizume leg. (KUM) • 3 exs.; Mt. Shaka-dake, Kitayabe, Yameshi; 18.V.2017; S. Imasaka leg. FIT (KUM). Saga-ken • 1 ex.; Kurokami-yama, Arita-chô; 27.IV.2018; M. Nishida leg. FIT (KUM) • 1 ex.; same locality; 9.V.2018; M. Nishida leg. FIT (KUM). Kumamoto-ken • 1♂; Momiki (alt. 890 m) [32.494, 130.988], Yatsushiro-shi; 24.V.2023; TS. Nozaki leg. LUM (KUM) • 1♀; Mt. Shiratomi-yama [33.4883, 130.9174], Yatsushiro-shi; 3.V.2022; Y. Uehara leg. (KUM). Oita-ken • 1♀, 3 exs.; Mt. Sobo; 17.V.1986; S. Nomura leg. (KUM) • 1 ex.; Tsukahara, Yufu-shi; 16.V.2014; T. Hada leg. (KUM). Diagnosis. This species is distinguished from other species of the genus by the following combination of characteristics: pronotal posterolateral angle distinctly acute (Fig. 15B); elytra distinctly widened posteriad entirely (Fig. 15B, C); metaventral process slightly produced (Fig. 15D); median lobe of aedeagus bulbous, length approximately 0.63 mm (Fig. 15G). The appearance of this species is similar to H. laevigata and H. prolongata, but it can be distinguished from H. laevigata by Dtsch. Entomol. Z. 72 (2) 2025, 525–555 dez.pensoft.net 549 Figure 15. Homoeusa gigantea sp. nov. A. Antenna; B. Pronotum and elytra; C. Zoomed view of elytron; D. Mesoand metaventrite; E, F. Posterior margin of 8th sternite: E. Male; F. Female; G. Median lobe of aedeagus from lateral view; H. Paramere of aedeagus from lateral view; I. Spermatheca. its normal long setae of pronotum and elytra, and from H. prolongata by its larger body, aedeagus, and distinct acute posterolateral angle. Description. Body (Figs 3F, 16E) large, broad, somewhat limuloid; dorsal surface mostly moderately polished. Head small; color yellowish brown to brown; eyes small. Antennae (Fig. 15A) short, relative length of each antennal segment from first to 11th, 2.91: 2.25: 1.66: 1.27: 1.18: 1.2: 1.23: 1.18: 1.00: 1.45: 4.93. Thorax. Pronotum (Fig. 15B) semicircular, transverse (PW/PL, 1.62–1.80), widest at posterior 1/3, postero-lateral angle distinctly acute, posterior margin distinctly sinuate, yellowish brown to brown, sometimes slightly transparent, surface finely covered with long setae and punctures, gently polished and slightly reticulated. Elytra (Fig. 15B, C) distinctly widened posteriad entirely, posterior margins deeply notched near lateral corners, yellowish brown to brown, surface finely covered with long setae and punctures; gently polished and weakly reticulated. Hind wings developed. Mesoventral process (Fig. 15D) very narrow, with indistinct medial carina, apex sharply pointed, reaching almost anterior margin of metaventrite. Metaventral process slightly produced (Fig. 15D).