Males

The species are often indistinguishable from each other in females based on external morphological characters; the most useful diagnostic characters are present in the males. 

1. At least head and mesoscutum completely testaceous or testaceous-reddish or whitish ...Aphelopus testaceus Olmi

- Head and mesoscutum completely or mostly black or brown ...2

2. Notauli absent, or slightly visible near anterior margin of mesoscutum ...3

- Notauli distinct, reaching at least 0.3 × length of mesoscutum ... 4

3. Male genitalia with basivolsella fused with paramere ...Aphelopus incisus Olmi

- Male genitalia with basivolsella not fused with paramere ...Aphelopus mediocarinatus (Benoit)

4. Notauli reaching approximately 0.3–0.8 × length of mesoscutum ...5

- Notauli complete or almost reaching posterior margin of mesoscutum (0.85–0.90 × length of mesoscutum) ...9

5. Male genitalia with basivolsella fused with paramere ...Aphelopus incisus Olmi

- Male genitalia with basivolsella not fused with paramere ...6

6. Basivolsella without lateral distal process ...Aphelopus wittei Benoit

- Basivolsella with lateral process ...7

7. Basivolsella with lateral proximal process; distivolsella with very slender distal part ...Aphelopus sequeirai Olmi, Copeland & van Noort

- Basivolsella with lateral medial or distal process; distivolsella broader ...8

8. Basivolsella with lateral distal process ...Aphelopus vernonensis Olmi

- Basivolsella with lateral medial process ...Aphelopus severancei Olmi, Copeland & Guglielmino

9. Male genitalia with basivolsella not fused with paramere, with lateral basal process ...Aphelopus mostovskii Olmi

- Male genitalia with basivolsella fused with paramere, without lateral basal process ...Aphelopus incisus Olmi