You deliver the wine to Drest, but he seems agitated by the sound of buzzing flies, so you decide to kill some swarms to calm him.
This quest is available if you have completed the quest Give a Man a Drink.
Starting the Quest
Talk to Drest in the western half of Eastern La Noscea to begin the quest.
Slay Dung Midge Swarms
Go outside. The minimap shows quest icons where you can find Dung Midge Swarms. Slay five swarms.
Speak with Drest
Go back into Drest's shack and talk to him to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Drest to accept the next quest: Battle Scars.