Agraphydrus Régimbart, 1903

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 (suppl.) 51, pp. 1-118 : 17

Genus Agraphydrus Régimbart, 1903

( Figs. 1A, 7–12, 44A, 45A)

Diagnosis. The genus Agraphydrus is similar to other genera of the Japanese Acidocerini , but is distinguished from them by the following characters: (1) head capsule with long scale-like setae ( Figs. 7, 9A, 10, 12C); (2) nasale with distinct teeth, not serrate or smooth ( Figs. 7C, 10C); (3) antennal sensorium (SE1) rather long ( Figs. 8A, 11A); (4) mandibles asymmetrical, left mandible with one inner tooth, right mandible with two teeth ( Figs. 8 B–C, 11B–C); (5) abdominal segments with spinose prolegs ( Figs. 12 A–B).