Oxyomus species

Key to Taiwanese Oxyomus species

1. Each elytron with 8 visible costae (sutural one counted, marginal one not, Fig. 2C View Fig ). Pronotum with the longitudinal median groove ( Figs. 2A, 2G View Fig , 7D View Fig ) ........................................ O. alligator View in CoL sp. nov.

- Each elytron with 10 visible costae (sutural one counted, marginal one not, Fig. 7J, 7K View Fig ). Pronotum without longitudinal median groove ( Fig. 7A–C View Fig ) ....................................................... 2

2. The first elytra interval with two well-separated rows of punctures thorought; both rows clearly separated at the level of metathorax, parameres longer and apex rather slender ( Fig. 7I, 7G View Fig ) ................. O. taipingensis Masumoto, Kiuchi & Wang, 2014 View in CoL

- The first elytra interval with two rows of punctures gradually fused towards apex; only a single row is present at the level of metathorax, parameres shorter and apex moderately rounded ( Fig. 7E–F, 7H View Fig ) ................................................................................... 3

3. Punctures on pronotal disc with very short setae, setae not reaching neighboring punctures ( Fig. 7O View Fig ). Elytral costae without micro-setae ( Fig. 7M View Fig ). 5 th elytral costa long and strongly developed, reaching as far as 7 th costa ( Fig. 7K View Fig ) ........................... .......................... O. nanxiensis Masumoto, Kiuchi & Wang, 2018 View in CoL

- Punctures on pronotal disc with longer setae, setae reaching neighboring punctures ( Fig. 7N View Fig ). Elytral costae with micro-setae ( Fig. 7L View Fig ). 5 th costa short and low, not reaching as far as 7 th costa ( Fig. 7J View Fig ) .......................................... O. masumotoi Nomura, 1973 View in CoL