(Fig. 48)
Material examined. 2 ♂, S Kholmsk, 25.IX, 09.X.2022.
Distribution. Russia (S RFE: SW * Sakhalin,?S Pimorskii Krai), Japan (Hokkaido, Honshu, Shikoku, Kyushu),? South Korea.
Remarks. The finding of V. phasma in Sakhalin significantly expands its distribution range to the north. The distribution of V. phasma in the continental East Asia is questionable. Reports of this species from Primorskii Krai (Viidalepp 1977: 564; Viidalepp 1996: 29; and subsequent references in Mironov et al. 2008: 218; Beljaev 2016: 633; Beljaev & Mironov 2019: 269; Beljaev & Mironov 2021) are apparently based on the specimen cited on the GBIF website, taken in Gornotajozhnaja village 19.VI.1979 (Kurina 2022h) (Table 2). However, V. phasma is an autumn species, flying in Japan (Kanto region) from mid-September to late October (Nakajima & Yazaki 2011). In Korea, Leech (1897: 77) reported that this species (as “ Hydrelia phasma ”) was caught “at Gensan in August”, which also does not correspond to the characteristic flight period for the imago. All subsequent information about V. phasma from Korea seems to be based on this report by Leech, with the exception of an additional report from South Jeolla Province by Kim et al. (2016: 396), but without a photo of the moth in the cited book. Therefore, it is necessary to confirm the distribution of V. phasma in Korea.
In Japan the larvae feed on the leaves and seeds of Fagus crenata (Fagaceae); in Sakhalin they apparently feed on Quercus mongolica subsp. crispula (Fagaceae).