Passage 8.53.1
τῷ δὲ Ἀπόλλωνι οἱ Τεγεᾶται τῷ Ἀγυιεῖ τὰ ἀγάλματα ἐπʼ αἰτίᾳ φασὶν ἱδρύσασθαι τοιᾷδε. Ἀπόλλωνα καὶ Ἄρτεμιν ἐπὶ πᾶσαν λέγουσι χώραν τιμωρεῖσθαι τῶν τότε ἀνθρώπων ὅσοι Λητοῦς, ἡνίκα εἶχεν ἐν τῇ γαστρί, πλανωμένης καὶ ἀφικομένης ἐς τὴν γῆν ἐκείνην οὐδένα ἐποιήσαντο αὐτῆς λόγον.
The Tegeans say they set up the statues of Apollo Agyieus for the following reason. They report that Apollo and Artemis exacted vengeance throughout this entire region upon those people who, at the time Leto wandered pregnant and came to their land, took no heed of her whatsoever.