Key to species of Thai Planiculus Hulcr & Cognato, 2010 (modified from Smith et al. 2020)

1 Elytral apex entire..................................................................................... 2

- Elytral apex emarginate................................................................................ 3

2. Elytral apex from dorsal view rounded, declivital interstriae armed with small granules, separated by at least 2× diameter of a granule........................................................................................ bicolor

- Elytral apex from dorsal view strongly angulate, armed with small granules separated by 1× diameter of a granule or less, no tubercle............................................................................... angulatus sp. nov.

3 Declivital interstriae1 armed with one distinctly larger tubercle and a few scattered granules....................... shiva

- Declivital interstriae1 armed with several granules...................................................... limatus