Diagnostic characters of Horaeomorphus hainanicus sp. n. A Left antenna of male, in dorsal view B Aedeagus, in ventral view C Same, in lateral view D Same, in dorsal view E Apical portion of paramere, enlarged F Endophallus, enlarged, in ventral view G Same, schematic H Spermatheca, in lateral view I Left metatrochanter of male, in ventral view. Scale bards: 0.5 mm (A); 0.2 mm (B, C, D); 0.04 mm (E); 0.1 mm (F, G, H); 0.3 mm (I).