Taxonomic key to males of Kinrentius

1 Pygofer, in lateral view, with apex acutely rounded, ventral margin with anteroventral (AVP) and posteroventral (PVP) processes (Figs 9–10, 18–19); aedeagus weakly constricted sub-basally between preatrium and shaft (Figs 14, 23)................ 2

- Pygofer, in lateral view, with apex broadly rounded (Fig. 10 in Wei, Dietrich & Webb 2010), ventral margin without processes; aedeagus strongly constricted sub-basally between preatrium and shaft (Wei, Dietrich & Webb 2010: Figs 22–26)........................................................................... K. constrictus Wei, Dietrich & Webb, 2010

2 Pygofer with posteroventral processes very short (PVP in Fig. 18); aedeagus with paired apical processes, each subquadrate with apical margin slightly serrate (Fig. 25)........................................ Kinrentius peruvianus sp. nov.

- Pygofer with posteroventral processes well developed (PVP in Figs 9, 10); aedeagus with paired apical processes, each acute with apical margin strongly serrate (Fig. 16)............................................................... 3

3 Pygofer with anteroventral (AVP) and posteroventral (PVP) processes multidentate, with several short teeth between processes (Fig. 9); aedeagus median portion with well-developed dorsal projection forming a distinct process (Fig. 14), apical paired processes, in lateral view, strongly expanded and with anterior margin broadly rounded (Fig. 14)..................................................................................................... Kinrentius catuaba sp. nov.

- Pygofer with anteroventral and posteroventral processes not multidentate, without teeth between processes; aedeagus median portion with dorsal projection small, tooth-like, and apical paired processes, in lateral view, moderately expanded and with anterior margin acute (Wei, Dietrich & Webb 2010: Figs 13, 20, 21)........... K. bispinosus Wei, Dietrich & Webb, 2010 .