Key to the species of the subgenus Phrator Semenov, 1922
1 Mandibles short, their external margin without wedge-shaped extension. Metafemora and mesofemora slightly exceeding the elytral margin.............................................................. Omophron (s.str.) Latreille, 1802
- Mandibles longer, their external margin with wedge-shaped extension. Metafemora and mesofemora strongly exceeding the elytral margin. Subgenus Phrator ........................................................................ 2
2 Elytra with 14 striae, ‘ variegatum’ group.................................................................. 3
- Elytra with 15 striae, ‘ vittulatum’ group................................................................... 6
3 Aedeagus moderately curved apically (Figs 45–49, 53–54).................................................... 4
- Aedeagus strongly curved apically (Figs 50–52). (Algeria, Portugal, Sardinia, Spain)......... O. variegatum Olivier, 1812
4 Elytral striae more or less strongly punctate. Species from Africa............................................... 5
- Elytral striae weakly punctate. Species from Madagascar (Fig. 20)...................... O. grandidieri (Alluaud, 1899)
5 Intervals 1-3 on the disc of elytra usually slightly convex (Figs 9–16). Egypt, Sudan, Eritrea, Ethiopia, Somalia, Kenya, Uganda, Cameroon, Democratic Republic of Congo, Botswana, Mozambique ............ O. multiguttatum s. str. Chaudoir, 1850
- Intervals 1–3 on the disc of elytra usually flattened (Figs 17–19). Southern third of the African continent (Angola, Namibia, Mozambique, South Africa)................................ O. multiguttatum ssp. depressum Klug, 1853 stat. nov.
6 Elytra elongated oval. Punctures on elytral striae well developed. Dark elytral pattern without metallic lustre (Figs 23–26).. 7
- Elytra almost circular. Dark elytral pattern with metallic lustre. Striae slightly punctate on disc and smooth on base. (Figs 21–22). (Nigeria, Cameroon).................................................... O. barsevskisi Valainis, 2011
7 Body size 8–9 mm. Elytral pattern blurred (Figs 23–25). (West Africa).................. O. vittulatum Fairmaire, 1894
- Body size 11–12 mm. Elytral pattern distinct (Fig. 26). (Democratic Republic of Congo)...... O. schoutedeni Deleve, 1924