Berosus sp.

Family: Hydrophilidae
Subfamily: Hydrophilinae
Tribe: Berosini

General appearance: body dorsoventral flattened with conspicuous lateral tracheal gills on abdominal segments I -VII and spiracular atrium absent (distinguished chacteristics for this genus); head subquadrate, mandibles strongly asymmetrical (left mandible shorter & with a small tooth), clypeolabrum asymmetrical.

 

Reference:

Minoshima, Yûsuke & Hayashi, Masakazu. (2011): Larval morphology of the Japanese species of the tribes Acidocerini, Hydrobiusini and Hydrophilini (Coleoptera: Hydrophilidae). Acta Entomologica Musei Nationalis Pragae 51(supplementum): 1–118.