Leptophion

Key to Japanese and Taiwanese species of Leptophion

1. Hind wing with uniform shaped hamuli on R 1, its penultimate hamulus not elongate. Proximal areas of marginal cell and second subdiscal cell of fore wing with a clouded area. The angle of an intersection of two veins of hind wing, R 1 and Rs, about 45°............................................................................ L. radiatus (Uchida, 1956)

–. Hind wing without uniform shaped hamuli on R 1, its penultimate hamulus significantly elongated (Figs 9, 10). Proximal area of marginal cell with a clouded area (Figs 14, 16). Second subdiscal cell of fore wing without a clouded area (Figs 15, 17). The angle of an intersection of two veins of hind wing, R 1 and Rs, about 90° (Figs 15, 17)............................... 2

2. Pterostigma with a transpicuous membranous area (Fig. 14). Mesopleuron strongly polished. Body small, length of fore wing 13.5 mm .............................................................. L. parvus Shimizu & Watanabe sp. nov.

–. Pterostigma without a transpicuous membranous area (Fig. 16). Mesopleuron various (Fig. 13). Body large, length of fore wing 15.0–18.0 mm.................................................................................... 3

3. Mesopleuron strongly polished without wrinkles. AI, 1.3–1.7......................... L. maculipennis (Cameron, 1905)

–. Mesopleuron with longitudinal wrinkles (Fig. 13). AI, 1.0................. L. septentrionis Shimizu & Watanabe sp. nov.