Key to Japanese species of the genus Gambrus
(female only)
1. Hind leg entirely black. Metasomal tergites entirely black except for a large median white spot of T VII. ............................................ Ga. wadai (Uchida, 1936)
-. Hind leg and metasomal tergites with a conspicuous red to reddish brown area (Fig. 7A)..................................................................................2
2. Hind tarsus black with conspicuous white bands (Fig. 7A). Hind coxa black (Fig. 7A). ............................................ Ga. homonae Sonan, 1930
-. Hind tarsus without conspicuous white bands, at most tinged with reddish brown. Hind coxa red...........................................................................................3
3. Metathorax and propodeum black. Hind leg reddish brown except for anterior part of tibia, femur and each tarsal segment blackish brown to black. ....................................... Ga. ruficoxatus (Sonan, 1930)
-.“Metathorax”red (= propodeum red?). Hind leg black, with femur towards the base and coxa red. .............................................. Ga. variator (Walker, 1874) (not seen by the author)