Taxonomic study on the queens of the Japanese ponerine genera, with a redescription of Ectomomyrmex horni restituted as a valid species (Hymenoptera: Formicidae) Author Yamane, Seiki Haruyama 1054 - Author Hosoishi, Shingo Institute of Tropical Agriculture, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819 - 0395, Japan Author Ito, Fuminori Faculty of Agriculture, Kagawa University, Ikenobe, Miki, Kagawa Pref. 761 - 0795, Japan text Acta Entomologica Musei Nationalis Pragae 2024 Acta. Ent. Mus. Natl. Pragae 2024-10-01 64 2 249 267 https://doi.org/10.37520/aemnp.2024.017 journal article 10.37520/aemnp.2024.017 1804-6487 14655612 E3DA805D-15F4-46DF-93C2-85C512C1ECBA Odontomachus Mayr, 1862 ( Figs 2F , 4F , 6F ) Recognition. Large ants measuring 9.4–10.2 mm in total body length; nuchal carina (occipital carina) running behind vertex turned anteriad medially on vertex forming V-shaped infolding, merging with median line of head; mandible very long, linear, apically strongly curved inward; petiole sharply pointed apically. Description. Large ants measuring 9.4–10.2 mm in total body length. Head longer than broad, broadest at level of eye, with posterior margin shallowly and broadly emarginate; lateral margin in front of and behind eye concave; nuchal carina (occipital carina) running behind vertex turned anteriad medially on vertex forming V-shaped infolding, merging with median line of head. Eye with rather long sparse hairs. Ocelli situated far from posterior margin of head; distance between posterior ocellus and posterior margin of head more than three times as long as distance between posterior ocelli. Mandible linear and long, inserted medially on front of cranium, apically strongly curved inwardly; in the two Japanese species apical portion with three teeth that are arranged vertically; upper tooth truncate apically. Metanotum flanked by deep anterior and posterior furrows. Opening of propodeal spiracle elongate. Petiole conical with pointed apex; subpetiolar process without anterior fenestra. Prora projected anteriad as small tongue. Gastral constriction weak; pretergite of gastral segment II generally concealed under tergite I, transversely striate; presternite with same sculpturation; cinctus not differentiated. Both mid- and hindtibiae with a simple spur and a longer pectinate spur. Hindwing with jugal lobe. Caste differences. In O. cf. monticola Emery, 1892 the worker differs from the queen in having the following characters: body slightly smaller (HW 2.01–2.24 mm in the worker vs . 2.28–2.44 mm in the queen); eye smaller (major diameter 0.30–0.33 vs . 0.38); ocelli absent; thorax without wings and simply constructed; mesoscutellum absent; groove dividing mesopleuron into upper and lower sections very faint. For more details for the entire genus see BROWN (1976) . Remarks. In the Japanese Odontomachus species , the antennal scape and mid- and hindtibiae bear no distinct erect hairs, while in Anochetus shohki these parts have erect hairs. Species examined (2/2). Odontomachus kuroiwae (Matsumura, 1912) and O . cf. monticola Emery, 1892 .