Key to the Japanese species of Amblopusa

1. Body longer than 3.0 mm; head, pronotum and elytra reddish brown; apical lobe of median lobe divided......... A. magna

- Body short, at most 2.5 mm long; head, pronotum and elytra yellowish brown; apical lobe of median lobe unilobed....... 2

2. Body about 1.5 mm long, parallel-sided......................................................... A. hokkaidona

- Body about 2.5 mm long, subparallel (between pronotum and elytra more constricted).............................. 3

3. Pronotum rather flattened with anterolateral margin angular; median lobe of aedeagus slightly swollen near apex in lateral view....................................................................................... A. pacifica

- Pronotum slightly convex with anterolateral margin rounded; median lobe of aedeagus apically acute in lateral view................................................................................................... A. brevipes