Final answer:
Aeneas is led to the Golden Bough by doves, symbolizing his status as an initiate in a quest parallel to the Argonauts. The bough is offered to Proserpina, granting him and the Sibyl access to Elysium in the underworld.
Step-by-step explanation:
Aeneas is led to the Golden Bough by a pair of doves sent by his mother, Aphrodite. These doves parallel the dove that guided the Argonauts through the Clashing Rocks in Apollonius of Rhodes' epic. The Golden Bough, which Aeneas is instructed by the Sibyl to present to Proserpina, is analogous to the Eleusinian Mysteries where participants carried a similar bough during rites and symbolizes Aeneas's undertaking as an initiate.
Furthermore, the Golden Bough and the Golden Fleece share commonalities, shining in the darkness of gloomy forests, thereby suggesting Virgil's Aeneid parallels to the Argonautica in terms of thematic quest elements.
When Aeneas reaches the entrance of the underworld, he performs the necessary rituals, which include sprinkling himself with fresh water and fixing the Golden Bough to the lintel above the entrance, practices associated with rites for chthonian gods. His offering of the bough to Proserpina allows him and the Sibyl access to Elysium, a joyful and blessed place where the souls await reincarnation.