Key to the Japanese species of Arotes (female)

1. Subalar prominence strongly striate; metapleuron extensively punctate to rugose-punctate (Fig. 4); hind femur without distinct ventral convexity (Fig. 7). Ovipositor sheath 1.9–2.0 times as long as hind tibia. Scutellum and postscutellum black............................................................................................ A. japonicus sp. nov.

- Subalar prominence sparsely punctate; metapleuron extensively punctate; hind femur with distinct ventral convexity (Figs 8, 9).................................................................................................. 2

2. Fore wing with one discrete dark marking, or lacking (Fig. 11); ovipositor sheath 2.4–2.5 times as long as hind tibia; basal part of S1 weakly convex ventrally in lateral view (Fig. 5); scutellum and postscutellum yellow....... A. moiwanus (Matsumura)

- Fore wing with two discrete dark markings (Fig.12); ovipositor sheath 1.9–2.0 times as long as hind tibia; clypeus yellow (Fig.3); basal part of S1 strongly convex ventrally in lateral view (Fig. 6); scutellum and postscutellum black................................................................................................... A. sugiharai Uchida