Discussion

Semiclaviger Wasmann, 1893 is placed in the tribe Clavigerini, where it is closely related to Pseudacerus Raffray, 1895 (2 described and more undescribed species in southern Asia) and Clavister Besuchet & Hlaváč, 2011 (one species in Fiji) by having neck region of head completely inserted into pronotum, not visible dorsaly. The three genera can be separated by following key.

1 Head, pronotum and elytra with long setae; pronotum evenly convex............................................ 2

- Head, pronotum and elytra with minuscule setae, hardly visible; pronotum concave on disc, lateral margins raised...................................................................................... Clavister Besuchet & Hlaváč

2 Setae on pronotum and elytra arranged in longitudinal lines; eyes not visible dorsaly; each elytron on posterior margin with trichomes located laterad; terminal antennomere subcylindrical............................... Semiclaviger Wasmann

- Setae on pronotum and elytra not arranged in longitudinal lines; eyes well-visible dorsaly; elytra lacking trichomes; terminal antennomere bulges into a club and flattened............................................... Pseudacerus Raffray

The similar structure of head is also encountered in the genus Tiracaleda Hlaváč, Parker, Maruyama & Fikáček, 2021 (one species in New Caledonia) but this genus is actually assigned into the tribe Tiracerini .