Oryctini, Mulsant, 1842

Costa, Leidiane O., Duarte, Paulo R. M., Iannuzzi, Luciana & Grossi, Paschoal C., 2022, Taxonomic revision and notes on natural history of the enigmatic beetle genus Gibboryctes Endrödi (Coleoptera: Melolonthidae: Dynastinae), Journal of Natural History 56 (1 - 4), pp. 191-225 : 221-222

Identification key to the genera of adult Oryctini of South America

1. Body convex dorsally in lateral view. Ventral area of metatarsomeres with a longitudinal row of bristles ......................................................................................................... 2

- Body flattened dorsally in lateral view. Ventral area of metatarsomeres bearing a brush of bristles........................................................................................ Platyphileurus Ohaus

2. Protibia tridentate ............................................................................................................................... 3

- Protibia quadridentate....................................................................................................................... 5

3. Colour black. Elytra nearly smooth, except for a deep sutural stria ............................... 4

- Colour reddish brown. Elytra with distinct rows of punctures................ Coelosis Hope

4. Mandibles bidentate............................................................................................ Megaceras Hope

- Mandibles tridentate.......................................................................... Megaceropsis Dechambre

5. Male head bearing a tubercle, never with a horn. Female pronotum with an anterior tubercle or concavity, or both combined .................................................................................. 6

- Male head bearing a prominent horn. Female pronotum simple, without anterior tubercle or concavity.......................................................................................................................... 8

6. Tergite VII bearing stridulatory apparatus.......................... .......................... Strategus Kirby.

- Tergite VII without stridulatory apparatus................................................................................. 7

7. Teeth small and triangular at galea. Pronotum similar in both sexes, without horn or deep concavity. Female abdomen bearing the ventrite V shorter than ventrite VI...... .............................................................................................................................. Gibboryctes Endrödi.

- Teeth strong and scythe-shaped at galea. Male pronotum with an anterior horn. Pronotal concavity deep in both sexes. Female abdomen bearing the ventrite V longer than ventrite VI.................... .................... Tetragus Duarte and Grossi , gen. nov.

8. Prosternal process conspicuous, produced between coxae. Female head with 1–2 tubercles, never with a prominent horn ................................................................................... 9

- Prosternal process quite reduced, nearly obsolete, confined below coxae. Female head with a prominent horn......................................... ......................................... Enema Hope.

9. Body elongated in overall aspect, subparallel laterally. Anterior margin of clypeus with 2 teeth separated by a wide emargination............ ............ Podischnus Burmeister.

- Body broader in overall aspect, rounded laterally. Anterior margin of clypeus convergent, rounded, or with 2 teeth separated by a small notch............................................. ................................................................................................................ Heterogomphus Burmeister.