Key to the species of the crassum group

1 Pronotum with anterior angles widely rounded, lateral margins with strong tooth-shaped projections. Lateral portions of elytra very wide. Body yellow-brown. Apical portion of median lobe wide, parameres narrow and very long, internal sac simple (Fig. 69). Body length: 3.20–3.27 mm. Habitus as in Fig. 58. China: Sichuan ........................... A. explanatum sp.n.

- Pronotum with more narrow anterior angles, lateral margins with indistinct to distinct small projections. Lateral portions of pronotum markedly narrower. Body reddish-brown to brown. Apical portion of median lobe narrower, parameres wider and shorter, internal sac with complex, large distal portion (Figs. 60, 62, 71).......................................... 2

2 Punctation of pronotum and elytra small and sparse. Aedeagus as in Fig. 71. Body length: 3.87 mm. Habitus as in Fig. 59. China: Sichuan ............................................................................ A. farkaci sp.n.

- Punctation of pronotum large, deep, and dense. Aedeagi different (Figs. 60, 62)................................... 3

3 Elytra short, slightly widened posteriad, about as long as combined wide. Median lobe rather narrow, parameres longer, markedly exceeding apex of median lobe (Fig. 60). Body smaller: 2.62–3.12 mm. Habitus as in Fig. 56. China: Yunnan ................................................................................................ A. crassum sp.n.

- Elytra subparallel-sided, long, longer than combined wide. Median lobe wide, parameres shorter, slightly exceeding apex of median lobe (Fig. 62). Body larger: 3.40 mm. Habitus as in Fig. 57. China: Yunnan .................. A. crenulatum sp.n.