Key to the Kohnometopus species
1. Dorsum with clearly deep and large punctures, embolium distinctly broad, distributed in Taiwan ................ K. yangi
-. Dorsum with tiny punctures, embolium narrow.............................................................. 2
2. Scutellum with large dark marking, evaporatory area broad and not triangular, femur entirely yellowish-brown, distributed in Malaysia ............................................................................ K. yasunagai sp. nov.
-. Scutellum with clear V-shaped marking, evaporatory area distinctly triangular, femur partly pale and brown with dark annulations, distributed in Japan (Ryukyu Arc.)............................................................ K. fraxini