Key to species of Andanus

1. Pygofer with ventral margin serrated (Figs 32, 33); aedeagus with pair of sublateroapical flanges with single subdorsoapical spine and single ventromedial spine (Fig. 36); subgenital plates very long, constricted medially, expanded and clublike toward apices (Fig. 34) ........... A. sordidus

1’. Pygofer without processes (Figs 12, 20, 21); aedeagus with pair of apical or dorsopreapical spines and with or without single ventroapical spine; subgenital plates not as above (Figs 5, 14, 22) ...................................................... 2

2. Pygofer with numerous long macrosetae covering entire dorsoapical half (Fig. 12); aedeagus with two pairs of apical spines directed caudad (Figs 15, 16), without single spine on ventral surface or long spines along shaft ......... ..................................................................... A. bimaculatus

2’. Pygofer with macrosetae limited to smaller patch not extended to apex (Figs 4, 21); aedeagus with one pair of long spines along shaft (Figs 7, 24), with or without preapical spines directed anterad and single spine on ventral surface ................................................................................. 3

3. Style with lateral lobe broadly rounded near base, apophysis without triangular lateral projection near mid-length (Fig. 23); aedeagus without short distal spines (Fig. 24) ... ............................................................................. A. raunoi

3’. Style with lateral lobe near base acute, apophysis with triangular lateral projection (Fig. 6); aedeagus with pair of short dorsoapical and single ventroapical spine (Fig. 7) .. ................................................ A. tambopixunensis sp. nov.