Key to the Japanese Genera of Liparocephalini

1. Labial palpus 3-segmented and segment II thinner than I........................................... Paramblopusa

- Labial palpus 2-segmented or incompletely 3-segmented or completely 3-segmented but, usually segment II as wide as I... 2

2. Body slender; abdominal segments III–VII almost parallel-sided; ligula long, reaching to 1/2 of segment I of labial palpus.. 3

- Body robust and some or less broad; abdomen more or less oval; ligula short, not reaching to 1/2 of segment I of labial palpus ................................................................................................... 4

3. Labrum wider than long; one medial seta presents on prementum....................................... Amblopusa

– Labrum semicircular; two medial setae present on prementum........................................ Halorhadinus

4. Body large, more than 5.0 mm; apical lobe of paramere broad and triangular........................... Liparocephalus

- Body small, less than 3.0 mm; apical lobe of paramere slender................................................. 5

5. Head oblong; tarsal formula 4-4-4 or 4-4-5; abdomen oval............................................... Diaulota

- Head rounded; tarsal formula 3-3-4; abdomen oblong oval................................... Rotundicephala gen. n.