(Fig. 6)
Material examined. 25 ♂, 7 ♀, Yasnomorskoe and Sokhonda mount., 11–13, 14–15, 17, 18–19.VIII.2020; 1 ♂, 2 ♀, Razdolnoe, 16, 17.VIII.2020.
Distribution. Russia (S RFE: SW * Sakhalin, S Kurils—Kunashir and Shikotan), Japan (Hokkaido, Honshu, Shikoku, Kyushu, Tsushima),? South Korea,?SW China.
Remarks. The finding of L. simplicior in Sakhalin significantly expands its distribution range to the north. In Japan known hostplants of the species are various species of Quercus (Fagaceae), Malus sieboldii, Prunus incisa, P. grayana and Sorbus commixta (Rosaceae). Trees of the last species are numerous around the collection localities. In Sakhalin the moths fly in August.
The specimens in BOLD from N and NE China identified as “ Lomographa simplicior ” (BIN ID: ACJ3123, sequence ID: WOTL1001-13 from Beijing Shi and GWOTL811-13 from Jilin, also in the GBIF as “cf. Lomographa simplicior ”, occurences 1415542470 and1415543101), both are actually Eudjakonovia pulverata (A. Bang-Haas). The presence of L. simplicior in South Korea needs to be verified as no actual specimens are known (Kim et al. 2001; Kim et al. 2016). Subspecies B. simplicior acutangulata Sterneck, and B. simplicior lidjanga Wehrli from Sichuan and Yunnan, judging from their descriptions, can represent the separate species (or two species). So, possibly L. simplicior is endemic to Japan and neighbouring islands.