Priochirus (Eutriacanthus), Jakobson, 1908

Key to species of subgenus Eutriacanthus from South China

1. Head: median tooth shorter than lateral tooth ..................... 2

– Head: median tooth longer than lateral tooth ...................... 3

2. Sides of pronotum convergent anteriorly; mentum with two distinct transverse ridges ....... P. ( E.) curtcornis, new species

– Sides of pronotum parallel; mentum with one transverse ridge ............................................... P. ( E.) unicolor (Laporte)

3. Lateral line vanishing before reaching protruding part of posterior margin of pronotum; 8th abdominal segment red ... ............................................... P. ( E.) pulchellus, new species

– Lateral line complete, reaching posterior margin of pronotum; 8th abdominal segment black ............................................... 4

4. Pronotum and elytra red; body size larger ( 13–15 mm) ........ .................................................... P. ( E.) bipunctatus (Fauvel)

– Pronotum and elytra black; body size smaller ( 9–11 mm) .... .................................................. P. ( E.) tonkinensis Bernhauer