Megaceras, Hope, 1837

Alvarez, Héctor Jaime Gasca, da, Claudio Ruy Vasconcelos, Fonseca & Ratcliffe, Brett C., 2008, Synopsis of the Oryctini (Coleoptera: Scarabaeidae: Dynastinae) from the Brazilian Amazon, Insecta Mundi 2008 (61), pp. 1-62 : 28

Key to the species of adult Megaceras of Brazilian Amazonia

1. Apex of clypeus with 2 teeth ( Fig. 59 ). Mandibles with 2 subequal teeth with acuminate apex ... ........................................................................................................... M. philoctetes (Olivier)

— Apex of clypeus truncate or slightly emarginate. Mandibles with 2 teeth different in size ....... 2

2(1). Elytra with sutural stria slightly impressed or absent. Head horn with apex rounded or slightly acuminated. Pygidium of females with strong transverse furrow ( Fig. 54 ), anterior half concave in lateral view .......................................................................................... M. laevipenne Prell

—- Elytra with sutural stria impressed. Head horn with apex slightly bilobed or strongly bifurcate. Pygidium of females covex in lateral view ............................................................................... 3

3(2). Apex of head horn slightly bilobed. Horns of pronotal prominence subparallel, curved down. Pronotum of females with 2 tubercles. Pronotum of females with 2 tubercles behind anterior margim and with a slight furrow between them ........................................ M. crassum Prell

—- Apex of pronotal horn bifurcate. Horns of pronotal prominence divergent, strongly curved down. Pronotum of females with 2 conical tubercles behind anterior margin, without slight furrow between them ............................................................................................. M. stuebeli Kirsch

Figures

Figure 58-63. Megaceras philoctetes. 58) Habitus. 59) Male head (dorsal view). 60) Male major. 61) Male minor (scale line: 5 mm). 62) Parameres frontal view. 63) Parameres lateral view (scale line: 2 mm).

Figure 51-56. Megaceras laevipenne. 51) Habitus. 52) Male head and pronotum (lateral view). 53) Male head (dorsal view). 54) Female pygidium (scale line: 5 mm). 55) Parameres frontal view. 56) Parameres lateral view (scale line: 2 mm).