Figures: 35, 62, 120, 139, 173-174, 196, 218
In addition to the Rhithrogeninae characteristics, the following combination of characteristics will identify the genus:
The combination of a vestigial median caudal filament (as in Fig. 9), absence of a dense fringe of setae on the anterior margin of the head capsule (Fig. 35), and reduced lamellae on gills 1 will differentiate larvae of Bleptus from other Rhithrogeninae.
The presence of a transverse ridge on the prosternum (Fig. 120), long, narrow hindwings (Fig. 174), and the absence of a transverse suture on the mesonotum (as in Fig. 114) will differentiate adults of Bleptus from all other Rhithrogeninae genera. Additionally, the bases of the forceps are expanded so that they meet medially (Fig. 139), and segment 1 of the foretarsi is longer than second 2 (as in Fig. 124).
Japan, Korea (Fig. 218).