Some say that Homer preceded Hesiod, some say Homer was more than one person.

Though Hesiod is the earliest source for some specific myths: those of Prometheus, Pandora and of The Golden Age, he has little to say about Demeter (Latin -Ceres) and Persephone.

Hesiod writes of Zeus (Latin -Jupiter) and Demeter as parents of
"White armed Persephone whom Aidoneus stole".
Hesiod makes a connection between Demeter and wealth. It is more frequent to come across references to the Lord of the Underworld -Hades or Aidoneus referred to as Pluto; Pluto means wealth.

Demeter's wealth is the grain store filled to the brim. Hesiod puts it poetically:
"Demeter gave birth to wealth, after lying with Iasius in a thrice-ploughed field."
meaning that Demeter gave Iasius (Demophoon or Triptolemos) the sacred duty of spreading the knowledge of how to grow wheat all around the world.

Going back to the name of the Lord of the underworld, there is perhaps a linguistic connection between Aidna/Aidoneus and Sicily -Aidna sounds like Etna.

And Aidna means hidden, invisible.
It is easy for the sound of the word Aidna to transform into a name: Hades

Where Hesiod fails in providing information about Persephone, he makes amends by providing a detailed description of the Underworld..

When the old gods, the Titans, were conquered by Zeus they were cast down into Tartarus -a deep hole running through the earth, a place of darkness and decay. Bronze doors were fastened by Poseidon to close the region of Tartarus away from the upper world.

Three heroes: Kotlos, Gyges and Briareos guard the gate.

Misty Tartarus is the source and end of the un-draining sea and starry heaven. Here (as in the Mesopotamian myths) all is dismal and dank. Tartarus is a vast chasm full of storm winds. Day and Night cross each other at the threshold of the bronze gate.

Day carries light, whilst night carries sleep, the kind brother of death.

Further on (I'm not too sure where further on from Tartarus may be -perhaps further on within Tartarus itself, beyond the bronze gates?) Further on there is the 'Echoing house of Hades' Cerberus the three headed dog, and Styx.

Styx was once used 'to swear by' for oath taking. Someone swearing a false oath and drinking from the river risks coma, nightmare and exile for nine years (a time period that crops up in the mythology of wolves/werewolf).

Styx was also the name of the daughter of Oceanus and Tethys.

From Hesiod [LINK] :
ll. 912-914) Also he came to the bed of all-nourishing Demeter, and she bare white-armed Persephone whom Aidoneus carried off from her mother; but wise Zeus gave her to him.

(ll. 969-974) Demeter, bright goddess, was joined in sweet love with the hero Iasion in a thrice-ploughed fallow in the rich land of Crete, and bare Plutus, a kindly god who goes everywhere over land and the sea's wide back, and him who finds him and into whose hands he comes he makes rich, bestowing great wealth upon him.