Sphinx morio subsp. arestus
Synonymized with Hyloicus morio as a subspecies by Derzhavets, 1979, Ent. Obozr.58: 114. Inoue, 1982, in Inoue et al., Moths of Japan2: 318, who was probably unaware of Derzhavets' paper, treated arestus as a subspecies of Sphinx pinastri. Reinstated implicitly as a subspecies of Hyloicus morio by Owada & Kishida, 1992, Mem. natn. Sci. Mus., Tokyo25: 168. Implicitly synonymized with Hyloicus pinastri as a subspecies by Zhu & Wang, 1997, Fauna Sinica Insecta 11: 201 (key), 202. Implicitly synonymized with Hyloicus morio morio by Danner, Eitschberger & Surholt, 1998, Herbipoliana4(1): 56. Reinstated as a subspecies of Sphinx morio by Kitching & Cadiou, 2000, Hawkmoths of the world: 68.
Very similar to Sphinx morio morio, the slight differences being: black stripe on tegula narrower, the stripe between it and the wing base duller grey; forewing upperside more uniformly grey, the brown shading on the hind margin less prominent; dark streak behind vein M1, itself faint in Sphinx morio morio, absent or vestigial; apical line fainter; Aedeagus with apical groove shorter than in Sphinx morio morio.