The larva and pupa of Heterogomphus dilaticollis Burmeister and Podischnus agenor (Olivier) (Scarabaeidae: Dynastinae: Oryctini) are described for the first time based on specimens from Colombia. Podischnus agenor is the first species in the genus to have its immature stages described. Keys to the third-instar larvae of genera in the tribe Oryctini and species of Heterogomphus are included. Data on larval natural history for both species are provided.