Oberthueria falcigera (Butler, 1878)

Zolotuhin, Vadim V. & Wang, Xing, 2013, A taxonomic review of Oberthueria Kirby, 1892 (Lepidoptera, Bombycidae: Oberthuerinae) with description of three new species, Zootaxa 3693 (4), pp. 465-478 : 471-472

Oberthueria falcigera (Butler, 1878)

Lagyra falcigera Butler, 1878 , Illustrations of Typical Specimens of Lepidoptera Heterocera in the Collection of the British Museum 2: 45, pl. 35, fig. 4. TL: “Hakodaté” [ Japan]. Holotype (by monotypy): ♀ (BMNH) [examined]. = Oberthüria caeca ab. rutilans Grünberg, 1911, in Seitz, Die Gross-Schmetterlinge der Erde 2: 190. TL: “ Japan ” [b. Niko]. Holotype: ♂ (ZMHU) [examined].

Material examined. ♀, holotype of Lagyra falcigera Butler, 1878 , Japan (BMNH); ♂, holotype of Oberthüria caeca ab. rutilans Grünberg, 1911, Japan | b. Niko | W. Blüthgen S. (ZMHU); 1 ♂, Sheji am Fuji, 1200 m, VIII 1916, H. Höne (ZFMK); 1 ♂, Tokyo, VI 1956 (ZFMK); ♂, Japan, Niigata, Ooshima-mura, 30.V 1996, leg. Sato (MWM); ♂, Japan, Niigata, Mt. Oomine (Yuzawa), 13–14.VII 1963 (MWM); 2 ♂, Japan, Honshyu, Nagano Pref., Kiso Onsen, 1000 m, 19–20.VI 1970, leg. J. Razowski (MWM); 2 ♂, Japan, Nagano, Todai, Hase-mura, 1100 m, 15.VI 1980, leg. Kinoshita (MWM); ♂, Japan, Hakone, Kanagawa, Ohiradai, 300 m, 22.VII 1989, leg. Y. Kishida (MWM); ♂, Central Japan, Nagano, Achi, Ina, 14.VI 1981, leg. Kinoshita (MWM); ♂, Japan, Tochigi Pref., Nasu, 21.VIII 1982, leg. A. Torikata (MWM); ♀, Japan, Hokkaido, Yufutsu, Shizukawa, 20 m, 13.VI 1999, leg. Hideki Kobayashi (NSMT). See also images on http://www.jpmoth.org/.

Description. Rather small congener (Figs 4–7), with short and broad wings, always of very dark ground colour varying from very dark dusty yellowish grey to smoky brown or greyish-brown, wing pattern darker and sometimes hardly visible. Submarginal field of the fore wing is sometimes suffused with greyish brown scales but often is concolorous with the hind wing submarginal field and is not prominent, with orange ones on the hind wing making colour contrast. Hind wing with angled outer margin, rarely forming a short bifurcate tail. Females can be paler, with pattern more distinct and serration of the hind wing more distinct and forming a short bifurcate tail. Black (dark) semilunar submarginal spots are usually reduced in both sexes. Male genitalia (Fig. 23). Uncus lobes wide but short, with apices obtuse and only apically pointed; valvae rather short, with short strong spinose right harpe and broad right apical spur.

Diagnosis. Small size, very dark ground colour without yellow or pinkish tint and without white suffusion and markedly angled but not tailed hind wings distinguish the species from other congeners. Dark postmedial fasciae are usually more diffuse and regular in course, and less zigzag than in other species. The species is endemic to larger Japanese islands and is not known from the Chinese mainland although it was repeatedly cited from there (see Chu & Wang Linyao, 1983, 1996). In all such cases all are misidentifications, some of dark forms of the preceding species, but more often of the species described here as new.

Bionomics. The moths are on the wing from June to late August and seemingly produce two generations per season. Acer and Quercus are known larval hosts. The caterpillar is illustrated on http://www.jpmoth.org/.

Distribution. The species is endemic for the Japanese Archipelago and is known from Hokkaido, Honshu, Shikoku and Kyushu. All records of the species from mainland China (Chu & Wang, 1983, 1996; Park et al., 1999) are misidentifications and correctly belong to melanic forms of O. caeca or other species.