Oxyambulyx japonica Rothschild, 1894, Novit. zool. 1: 87. Type locality: Japan: Kiushiu [Kyushu].
[Further details on this species in Japan, as well as photos of many stages, can be found on Digital Moths of Japan as well as Moths of the southern Shikoku, Japan.]
Sexually dimorphic. In the male genitalia, abdominal sternum A8 with two tubercles internally near middle of apical margin and which are a little higher and father apart than in Ambulyx subocellata. Gnathos less deeply sinuate than in Ambulyx placida. Harpe resembling that in Ambulyx placida: ventral process triangular, pointed; other process composed of two lamelliform ridges the upper edges so bent towards each other that a hollow cylinder if formed and produced distad. Phallus somewhat bent, its apical edge developed into a short, strongly chitinised hook.
Mid-elevation monsoon evergreen broad-leaved forest. Attracted to light at night (Jiang, Kitching, Xu, Xu, Yan, Yu, Liu & Hu, 2025).
Japan: 5-27.v (Honshu); 2.vi (Honshu); 4.vi (Shikoku); 14-30.vi (Honshu); 1-16.vii (Honshu); 29.vii (Tsushima).
OVUM:
LARVA: See Moths of the southern Shikoku, Japan.
PUPA:
Larval hostplants. Recorded from Acer (Inoue et al., 1982) and Carpinus japonica (Nakamura, 1977). Yano (1994) reared it on Carpinus laxiflora and Carpinus tschonoskii. Juglans mandschurica and Rhus javanica were refused.
Unknown.
Japan: Honshu (Takao-San; nr. Hinoharu; Tokyo; Mikaboyama, 750m; Namezawa Spa, 700m; Bushi; Mononoki Spa, 950m; Kure, Hiroshima Prefecture); Shikoku (Ino); Kyushu; Tsushima (Sasuna).
Endemic to Japan.
Map: Distribution of species of the Ambulyx placida-group: Ambulyx japonica japonica (blue dots); Ambulyx japonica koreana (pink patch); Ambulyx japonica angustifasciata (green dots); Ambulyx placida (ochre squares); Ambulyx semiplacida semiplacida (red dots); Ambulyx semiplacida montana (black dots); Ambulyx semiplacida interplacida (orange patch); Ambulyx semiplacida bhutana (yellow dots); and Ambulyx wukong (purple squares). (© Jiang, Kitching, Xu, Xu, Yan, Yu, Liu & Hu, 2025).