According to Apollodorus, after the command of the Delphic oracle, two maidens were sent to Ilion, and their duty was to clean the temple. After their death, they were replaced, while the tribute ended after a thousand years with the end of the Phocian War, which destroyed Naryca, the town that supplied the maidens.
Aelian says that the plague, fell upon Locris after the Locrians failed to send the yearly tribute that the oracle demanded. Demetrius of Scepsis knows that the maidens were sent for the first time "when the Persians were already in control", so after 547 BC.