Genus Hydrochara Berthold, 1827

(Figs. 2 A–B, 51A, 52–55, 64A–B, 65B, 67B)

Diagnosis. This genus is distinguished from Japanese Hydrophilini by the following combination of characters: (1) frontal lines V-shaped (Fig. 54A); (2) nasale without distinct teeth, slightly serrate (Figs. 52C, 55A); (3) inner face of scape strongly serrate in first instar (Fig. 53A); (4) three setae (AN7–9) close to antennal sensorium (SE1) (Fig. 53A); (5) mandibles symmetrical, with two inner teeth (Figs. 53 B–C, 55D–E); (6) abdominal segments with long setiferous projections on each side (Figs. 2 A–B, 51A).