| 1 | Elytra with distinct parasutural furrows | 2 |
| - | Elytra without distinct parasutural furrows | 3 |
| 2 | Body length 2.7-2.9 mm; elytra without pale yellow spots at base; median lobe bearing lateral subapical rows of stout spines (Jia et al, 2013: figs 3-5) | L. qinlingensis Jia, Gentili & Fikacek |
| - | Body length 1.8-2.1 mm; base of elytra with two or four distinct pale yellow spots; median lobe without lateral subapical rows of spines (Zhang and Jia 2017: figs 6, 7) | L. yinziweii Zhang & Jia |
| 3 | Body length 2.0-2.8 mm; elytral borders and epipleura are swollen at base; median lobe narrowly pointed apically (Gentili 1995: figs 52, 53) | L. nitidus Gentili |
| - | Body length 1.8-2.1 mm; elytral borders and epipleura are not swollen at base; median lobe rounded apically | 4 |
| 4 | Apical part of the median lobe without series of fine setae. Elytra completely black at the base. Species from Hainan and Taiwan | 5 |
| - | Apical part of the median lobe with series of fine setae. Elytra with or without pale basal spots. Continental species | 6 |
| 5 | Median lobe strongly constricted subapically (Jia et al. 2013: figs10-12). Hainan | L. hainanensis Jia, Gentili & Fikacek |
| - | Median lobe indistinctly constricted subapically (Jia et al. 2013: figs 14-16). Taiwan | L. politus Gentili |
| 6 | Elytral series regular throughout; primary series of punctures distinctly stronger and coarser than secondary ones; median lobe ca. of the same width in apical half (Figs 5, 6) | L. motuoensis sp. nov. |
| - | Elytral series somewhat irregular at base, with some secondary punctures at least as large as those on primary series; median lobe distinctly widened apically (Figs 20-22) | L. yunnanensis Gentili |