A region of Sicily, modern Ibla, around the city of Ragusa, and much-hellenized trading post famous in antiquity for its flowers and excellent honey. The poet Martial seems to hold it as a rival to the famous honey of Hymettus in Attica:

Vivida cum poscas epigrammata, mortua ponis
lemmata. Qui fieri, Caeciliane, potest?
mella iubes Hyblaea tibi vel Hymettia nasci,
et thyma Cecropiae Corsica ponis api!

When you demand those vivid epigrams, you suggest a withered title
Caecilianus, who after all can do it?
You order that Hyblaean or Hymettian honey be made for you
and give Corsican thyme to a Cecropian bee!

In other words, Caecilianus demands poetry in poor taste; he demands something the author isn't fit to give. So, the metaphor, he demands a Sicilian bee use Attic flowers; the two honeys, both famed for taste, are not comparable.

It's close to impossible to over-estimate the importance of honey as the only real sweetener available to the ancient kitchen, and for good honey, Hybla was the closest source. It was mixed with wine, used as a preservative and marinade; Apicius gives a recipe for Ova Spongia ex Lacte, or egg-sponge with milk. A modern adaptation:
  • 4 eggs
  • 1/2 cup of milk
  • 4 tablespoons olive oil
  • honey, to taste

Combine the milk, oil, and eggs. Add a little of the oil to a pan and heat. Pour in the eggs, and cook the omelette without folding. Sprinkle with honey and ground pepper, to taste

A simple recipe for a simple dessert; the combination of honey and pepper were common to Roman cooking, and it is remarkable that this survived in a book designed for exclusive tastes.

Because of its natural association with Sicily and the fame of its pastoral beauty, Hybla became associated with the father of Bucolics, Theocritus; Calpurnius Siculus writes in his 4th Eclogue:

Tityrus hanc habuit, cecinit qui primus in istis
Montibus Hyblaea modulabile carmen avena

Tityrus had this, who first sang on these very mountains
his plaintive song upon his own Hyblaean pipes.

Tityrus is a reference to Eclogues I, and so represents Vergil himself, who took up the Sicilian song of Theocritus.