(Fig. 10H)
Material examined. Russia: AO, Skovorodino, nearby the train station, 53.98N, 123.93E, 431 m alt., Salix sp., 26. VI.2016, 1 larva, NK565, MK 403711; SO, Sakhalin Island, Yuzhno-Sakhalinsk, Gagarin Park, 46.97N, 142.75E, 69 m alt., Salix sp., 11.VII.2017, 1 larva, NK620, MK 403678, deposited in INRA.
Leaf mine. The blotch mine is usually bigger than in other Caloptilia spp. listed above, more strongly contorted (that reminds Phyllonorycter mines), situated along the leaf margin, and is preceded by a relatively long, easily distinguishable epidermal tunnel which starts near the main or a secondary vein (Fig. 10H). After vacating the mine, the larva moves to the leaf tip (often on the neighbor leaf), bends it downwards creating a triangular cone in which it continues feeding (Fig. 10H). Pupation is external, in a cocoon on the low side of the leaf.
Trophic specialization. Mainly oligophagous on Salicaceae: Salix, Populus, Chosenia, rarely found on Betulaceae (Betula), Myricaceae (Myrica gale), Fabaceae (Robinia pseudoacacia) (Baryshnikova 2016; De Prins & De Prins 2018; Ellis 2018).
Distribution. Russia: RFE—AO, KK, PK, SO, KamK; Siberia, European part (Baryshnikova 2008, 2016); Japan, China, Korea, Mongolia, India, North Africa, Central Asia, Asia Minor, Caucasus, Europe, Canada (De Prins & De Prins 2018).