Trichopteryx hemana

Trichopteryx hemana (Butler)

(Figs 28, 29, 61a, 61b, 62a, 62b)

Trichopteryx hemana: Beljaev & Mironov 2019: 257 (Sakhalin).

Trichopteryx incerta, nec Yazaki: Beljaev & Mironov 2019: 257 (Sakhalin).

Material examined. 1 ♂, “Saghalien Cent. Exp. Sta., Takinosawa [20 km NW of Uzhno-Sakhalinsk, railway station Pereval, 47°03′N, 142°31′E] 13.VI.1934 ”; S Kholmsk: 1 ♂*, 1 ♀, 22.V.2016; 1 ♂, 1 ♀, 14.VI.2017; 2 ♂, 2 ♀, 23, 31.V, 01.VI.2018; 3 ♂, 1 ♀, 16, 25, 30.V.2019; 1 ♂, 1 ♀, 24.V.2021; 1 ♂, 28.V.2022.

Distribution. Russia (S RFE: S Sakhalin, S Kurils—Kunashir (Rybalkin et al. 2022), S Khabarovskii Krai, S Amurskaya Oblast, Primorskii Krai), Japan (Hokkaido, Honshu, Shikoku, Kyushu, Tsushima), North Korea, South Korea, NE China.

Remarks. The finding of T. hemana in Sakhalin significantly expands its distribution range to the northeast. The larvae are polyphagous on broadleaved trees, in Japan noted on Quercus (Fagaceae), Acer (Sapindaceae) and Hamamelis (Hamamelidaceae). In Sakhalin the moths fly from mid-May to mid-June.

The report of T. incerta from Sakhalin by Beljaev & Mironov (2019, 2021) is erroneous. It was based on a shabby male with the “unusual” male genitalia, which is marked with an asterisk in the Material examined. Unlike the other examined specimens of T. hemana from Russian Far East, which have the distal projection of a valvula almost digital and the excision between this projection and the costa of valva deep (form A, Fig. 61a), this specimen from Sakhalin has wide triangular the distal projection of a valvula, and shallow the excision between this projection and the costa of valva, and somewhat shorter distal process of sacculus (form B, Fig. 62a). This makes general shape of the genitalia similar to those of T. incerta (see Yazaki 1978; figs 3, 4; Choi 2007a: figs 13, 22; Choi 2012: figs 154, 233; Hashimoto 2021: fig. 69 [uncus looks to be broken off distally]). But both these forms possess almost identical aedeagus which is strictly characteristic for T. hemana (Figs 61b, 62b). Hashimoto (2021) illustrated both these shapes of valva in the moths from Japan (loc. cit.: fig. 14: A, E—form B; fig. 14: B—form A), whereas from the continental East Asia only form A is known (for Korea see Choi 2007a, fig. 11, and Choi 2012, fig. 150; and for China see Xue, Zhu 1999, fig. 135). Possibly, T. hemana in the current understanding contains two “cryptic” species with the similar moths without distinct differences in the wing pattern. Of these, one is widespread in East Asia, and the other one limited to Japan and the adjacent islands. However, polymorphism in the male genitalia is also not excluded, because we have not yet been able to find T. hemana specimens that differ either in appearance or in the female genitalia, which could be associated with this male. Therefore, we retain identification of the form B as T. hemana. This issue requires a separate study.