Key to species of the Rhyzodiastes (Temoana) singularis species-group, modified based on Bell & Bell (1985, 2000)
1 Metasternum with median sulcus......................................................................... 2
- Metasternum without median sulcus....................................................................... 4
2 Median sulcus incomplete, limited to posterior half. Temporal lobes convergent posteriorly....... R. convergens Bell & Bell
- Median sulcus complete. Temporal lobes not convergent posteriorly............................................. 3
3 Temporal lobe with one unique seta in disc, besides the usual one in orbital groove. Basal setae present on antennomeres VI–X. Median groove deep, sublinear in middle 1/3............................................ R. bipunctatus Bell & Bell
- Temporal lobe only with one usual seta in orbital groove. Basal setae absent, only antennomere X with one or two. Median groove with moderate width, as wide as median pits................................................ R. xii sp. nov.
4 Sutural stria absent or only represented by a few punctures..................................................... 5
- Sutural stria impressed................................................................................. 6
5 Median groove obsolete. Parasutural stria setose............................................. R. singularis (Heller)
- Median groove impressed. Parasutural stria without setae.................................. R. guineensis (Grouvelle)
6 Median groove between pits linear. Temporal lobe with two setae in orbital groove................ R. mindoro Bell & Bell
- Median groove not as narrow. Temporal lobe only with one usual seta in orbital groove.............................. 7
7 Outer carina of pronotum strongly narrowed anteriorly; pronotum without distinct front angles. Outer antennomeres cylindri- cal, twice as wide as long............................................................. R. indigens Bell & Bell
- Outer carina only slighly narrowed anteriorly, truncate at apex; pronotum with distinct front angles. Outer antennomeres spha- eroid, about 1.5 wider than long.......................................................................... 8
8 Apex of pronotum wider than base; median groove nearly linear, much narrower than anterior median pit. Antenna without basal setae.............................................................................. R. mirabilis (Lea)
- Apex of pronotum slightly narrower than base; median groove dilated, as wide as anterior median pit. Antenna with sparse basal setae on antennomeres VIII–X.................................................... R. rimoganensis (Miwa)