Key to males of Rotigonalia Young
1. Aedeagus with pair of clawlike processes at apex (Fig. 5) .............................................................................................................. 2
- Aedeagus without apical processes ................................................................................................................................................. 3
2. Pygofer 2.5x longer than wide; style apices directed outwards; body length 5.7–5.8 mm ............................ R. larissae Cavichioli
- Pygofer 1.5x longer than wide; style apices directed inwards (Fig. 4); body length 9.5 mm ................................. R. regina sp. nov.
3. Aedeagus bicurved, in lateral view with basidorsal lobe bearing tuft of setae ............................................... R. curvula Cavichioli
- Aedeagus not as above ..................................................................................................................................................................... 4
4. Paraphyses with rami straight, in lateral view with apices broadened and truncate ........................................ R. olivacea Cavichioli
- Paraphyses with rami curved dorsally, with apices acute............................................................................ R. concedula (Melichar)