3.2.4.4. Omalium japonicum Sharp, 1874

(Figs 15, 33, 36–37)

Omalium japonicum Sharp, 1874: 98; Watanabe 1990: 95; Kim & Ahn 2014: 153.

Omalium (Omalium) japonicum: Bernhauer & Schubert 1910: 54.

Type material examined. Lectotype (here designated) ♂ (Fig. 33): ‘ Japan. [underlined by yellow] | G. Lewis | 1910-320.’ <printed>, ‘ Nagasaki. | 13.11.–21.IV.[18]81.’ <printed>, ‘ Omalium | japonicum Sharp, 1874 | Shavrin A. V. 2025 ’ <printed>, ‘LECTOTYPE | Omalium | japonicum Sharp, 1874 | Shavrin A.V. des. 2025’ <red, printed> (BMNH) .

Paralectotypes: 3 ♂♂, 3 ♀♀ (one specimen dissected; one specimen with handwritten numbers on the same plate below the specimen: ‘4.81 <in black> | 9.4.[18]81 <in red>’; one specimen with additinal handwritten label: ‘ Omalium japonicum’): first two labels same as in lectotype, with additional printed label: ‘ Omalium | japonicum Sharp, 1874 | Shavrin A. V. 2025 ’ (BMNH) .

Material examineD. JAPAN: 2 ♀♀: ‘ Type’, ‘ Japan. G. Lewis 1910-320.’, ‘ Sharp Coll. 1905-313.’, ‘ Omalium japonicum Type D.S. ’, ‘NHMUK015009856’ (BMNH); 2 ♀♀, 1 unsexed specimen (without abdomen): ‘Japan. G. Lewis 1910-320.’ (BMNH); 1 ♀: ‘227’, ‘Japan. G. Lewis 1910-320.’ (BMNH); 6 ♂♂, 5 ♀♀: ‘Japan. G. Lewis’, ‘Sharp Coll. 1905-313.’ (BMNH); 1 ♂, 1 ♀: same the first two labels as the previous, with additional label: ‘W. Steel coll B.M. 1969-552.’ (BMNH); 1 ♀: same first two labels as the previous, with additional label: ‘ Omalium japonicum’ (BMNH); 1 ♀: ‘227’, ‘ Japan. G. Lewis 1910-320.’, ‘ Omalium japonicum mihi D.S. ’ (BMNH); 1 ♂: ‘ Kanagawa Japan. Sauter’, ‘japonicum Shp’, ‘ M. Cameron. Bequest. B.M. 1955-147.’ (BMNH); 1 ♀: ‘Japan. G. Lewis 1910-320.’, ‘Yokohama.’ (BMNH); 1 ♂, 1 ♀: the first label as the previous, with additional label: ‘Miyanoshita. 24.IV.–3.V.80.’ (BMNH); 1 ♀: ‘JAPAN Kobe Mayasan 15.X.28 JEA Lewis’, ‘ M. Cameron Bequest. B.M. 1955-147.’ (BMNH); 2 ♀♀: ‘JAPAN Kobe Shinohara 8.XI.27 JEA Lewis’ (BMNH); 2 ♂♂: ‘JAPAN Satsuma Sakurajima. 10.III.12. JEA Lewis’, ‘ Omalium japonicum’, ‘ M. Cameron Bequest. B.M. 1955-147.’ (BMNH); 1 ♀: ‘ Daibosatsu Pass Yamanashi-pref. May-20 th 1961 Coll. K. Mizusawa’ (BMNH); 1 ♂: Ibaraki Prefecture, Mt. Tsukuba vic. 11.11.2001. P. Jałoszýnski leg. (cSh) .

Remarks. Omalium japonicum was originally described from Nagasaki based on an unspecified number of syntypes. I designate the male from BMNH as the lectotype in order to fix the identity of the species. It was redescribed by Watanabe (1990) and Kim & Ahn (2014).

Habitus as in Fig. 33. Measurements of the studied specimens: HW: 0.44–0.52; HL: 0.30–0.37; OL: 0.15–0.17; TL: 0.04–0.06; AL (lectotype): 0.80; PL: 0.43–0.45; PWmax: 0.57–0.62; PWmin: 0.51–0.56; ESL: 0.74–0.78; EW: 0.81–0.67; MTbL (lectotype): 0.45; MTrL (lectotype): 0.22 (MTrL 1–4: 0.09; MTrL 5: 0.13); AW: 0.79–0.85; AedL: 0.49–0.52; BL: 2.15–2.90 (lectotype: 2.65). Aedeagus as in Figs. 36–37. Female accessory sclerite as in Fig. 15.

It was recorded from Honshu several times (see checklist above). To the present date, O. japonicum is known from several localities in Honshu, Japan (e.g. Watanabe 1990) and South Korea (Kim & Ahn 2014). Schülke & Smetana (2015) recorded it from Jiangsu and Shanghai (China) without providing the exact localities, so these records require confirmation.