Passage 8.26.7
τῆς δὲ Ἀθηνᾶς τὸ ἄγαλμα πεποίηται χαλκοῦ, Ὑπατοδώρου τε ἔργον, θέας ἄξιον μεγέθους τε ἕνεκα καὶ ἐς τὴν τέχνην. ἄγουσι δὲ καὶ πανήγυριν ὅτῳ δὴ θεῶν, δοκῶ δὲ σφᾶς ἄγειν τῇ Ἀθηνᾷ· ἐν ταύτῃ τῇ πανηγύρει Μυάγρῳ προθύουσιν, ἐπευχόμενοί τε κατὰ τῶν ἱερείων τῷ ἥρωι καὶ ἐπικαλούμενοι τὸν Μύαγρον· καί σφισι ταῦτα δράσασιν οὐδὲν ἔτι ἀνιαρόν εἰσιν αἱ μυῖαι.
The statue of Athena is made of bronze, a work of Hypatodorus, and is worthy of inspection both for its size and its artistry. They hold a festival in honor—I think—of Athena; and during this festival they first sacrifice to Myagros, offering victims and praying to the hero, invoking him under the name Myagros. After performing these rites, flies no longer trouble them.