Key to species of Cornugon

1. Upper part of frons with two pointed protrusions resembling "horns" (Figs 14, 15, 19, 23)............................ 2

- Upper part of frons either with one pointed protrusion medially (Fig. 48), without protrusions (e.g. Figs 2, 33) or with rounded protrusions (Fig. 38)................................................................................... 4

2. Mesonotum with a small, transverse fovea between midlobe of mesoscutum and scutellum (Fig. 16); scape, femora and tibiae dark brown with metallic tinges............................................... C. bicornis sp. nov. (female, male)

- Mesonotum with a large, more or less quadrangular or round fovea between midlobe of mesoscutum and scutellum (Figs 21, 26); scape, femora and tibiae white........................................................................ 3

3. Petiole widest and with irregular transverse carinae in anterior half, and with a constriction posteriorly (Fig. 22).................................................................................... C. diabolos sp. nov. (female, male)

- Petiole narrowest anteriorly and gradually increasing in width posteriorly, and dorsally reticulate with small meshes (Fig. 27)........................................................................... C. diceros sp. nov. (female, male)

4. Upper part of frons with one pointed protrusion medially (Fig. 48)........................ C. unicornis sp. nov. (female)

- Upper part of frons without pointed protrusions (e.g. Figs 2, 33) or with rounded protrusions (Fig. 38).................. 5

5. Coxae white to yellowish-white.......................................................................... 6

- Coxae dark brown..................................................................................... 7

6. Scutellum with a median groove extending entire length, and posterior ½ with weak reticulation (Fig. 3); propodeum 0.4X as long as wide measured between spiracles, and without groove along anterior margin (Fig. 5)... C. albicoxa sp. nov. (female)

- Scutellum with a median groove in anterior ½ only, and predominantly with strong reticulation (Fig. 9); propodeum 0.2X as long as wide measured between spiracles, and with a wide groove along anterior margin (Fig. 11).. C. anais sp. nov. (female)

7. Scutellum with a strong median groove in anterior 2/3 (Figs 36, 39); propodeum with a median carina (Figs 37, 40)....... 8

- Scutellum without median groove (Figs 30, 45); propodeum without median carina (Figs 31, 47)...................... 9

8. Mesoscutum predominantly reticulate (Fig. 39); propodeal plicae parallel (Fig. 40).......... C. petiolatum sp. nov. (female)

- Mesoscutum predominantly smooth and shiny (Fig. 36); propodeal plicae converging posteriorly (Fig. 37)............................................................................................ C. leios sp. nov. (female, male)

9. Vertex anteriorly and upper part of frons with strong reticulation (Figs 42–44); upper posterior surface of hind coxa with more than 10 long hairs....................................................... C. reticulatum sp. nov. (female, male)

- Vertex entirely and upper part of frons smooth and shiny (Figs 28, 29); upper posterior surface of hind coxa with less than 5 long hairs..................................................................... C. gibberum sp. nov. (female)