(Fig. 49)
Material examined. 1 ♂, 2 ♀, S Kholmsk, 21, 24.V, 9.VI.2021.
Distribution. Russia (S RFE: SW * Sakhalin, S Kurils—Kunashir (Rybalkin et al. 2022), S Khabarovskii Krai, Primorskii Krai), Japan (Hokkaido, Honshu, Shikoku, Tsushima), South Korea.
Remarks. The finding of V. semistrigata in Sakhalin significantly expands its distribution range to the northeast. In appearance, the specimens from this island, as well as from Kunashir (Rybalkin et al. 2022, fig. 38), differ from the continental ones and are similar to those from Hokkaido in having moderately expressed and some brownish traverse lines on the wings and a very light brown stripe outward from the black postmedial line between the veins R and CuA1 on the forewing. Inoue (1963, 1977; and after them other Japanese authors) associated V. semistrigata from Hokkaido with the nominative subspecies V. s. semistrigata, whereas the moths with a brighter colouration of the wings from more southern Japanese islands were separated in subspecies V. semistrigata expressa Inoue. However, V. semistrigata from Sakhalin and Hokkaido differs in appearance both from the continental nominate subspecies and from V. s. expressa.
The known hostplant in Japan is Photinia villosa (Rosaceae), belonging to the apple subtribe Malinae. This plant is absent in Sakhalin; possibly, the species from the genera Malus and / or Sorbus could be the hostplants for V. semistrigata on the island.