Laudator Temporis Acti

Propertius 2.12.1-16 (tr. A.S. Kline):

Whoever he was who first depicted Amor as a boy, don't you think he possessed a wonderful touch? He was the first to see that lovers live without sense, and that great good is lost in trivial cares. Also, with meaning, he added the wings of the wind, and made the god hover in the human heart: true, since we're thrown about on shifting winds, and the breeze never lingers in a single place. And it's right that his hand should grip barbed arrows, and the Cretan quiver's hung across his shoulders, since he hits us before we can safely see the enemy, and no one escapes unwounded from his hurt. His darts remain in me, and his form, of a boy, remains, but surely he's lost his wings, since he never flies anywhere else but in my heart, and, oh, he wages war endlessly in my blood.

Quicumque ille fuit, puerum qui pinxit Amorem,
  nonne putas miras hunc habuisse manus?
is primum vidit sine sensu vivere amantis,
  et levibus curis magna perire bona.
idem non frustra ventosas addidit alas,
  fecit et humano corde volare deum:
scilicet alterna quoniam iactamur in unda,
  nostraque non ullis permanet aura locis.
et merito hamatis manus est armata sagittis,
  et pharetra ex umero Cnosia utroque iacet:
ante ferit quoniam, tuti quam cernimus hostem,
  nec quisquam ex illo vulnere sanus abit.
in me tela manent, manet et puerilis imago:
  sed certe pennas perdidit ille suas;
evolat heu nostro quoniam de pectore nusquam,
  assiduusque meo sanguine bella gerit.

I'm sure someone else has already noted the following parallels, but I don't have a commentary on book 2 of Propertius to check.

Servius on Vergil, Aeneid 1.663:

Because desire for disgrace is foolish, Cupid is depicted as a boy, as "Among whom Clymene was telling about [Vulcan's] foolish passion" [Georgics 4.345], i.e. his love; likewise because with lovers speech is halting, like it is with a boy, as "She starts to speak, but she stops in the middle of her utterance" [Aeneid 4.76]. Moreover he is winged for this reason, because nothing is found more flighty or fickle than those in love, as is proved in Dido herself; for she is thinking about Aeneas' destruction, but a little while earlier she was perishing for love of him, as "Could I not have seized his body and torn it to pieces?" [Aeneid 4.600]. Cupid is said to carry arrows for this reason, because they too are unpredictable and swift.

nam quia turpitudinis est stulta cupiditas, puer pingitur, ut "inter quas curam Clymene narrabat inanem," id est amorem, item quia inperfectus est in amantibus sermo, sicut in puero, ut "incipit effari mediaque in voce resistit." alatus autem ideo est, quia amantibus nec levius aliquid nec mutabilius invenitur, ut in ipsa probatur Didone; nam de eius interitu cogitat, cuius paulo ante amore deperibat, ut "non potui abreptum divellere corpus." sagittas vero ideo gestare dicitur, quia et ipsae incertae velocesque sunt.

Cf. Athenaeus, Deipnosophistae 13.562 c-d (tr. Charles Burton Gulick):

And Eubulus, or Ararôs, says in The Hunchback: "Who was the fellow, I wonder, who first painted or modelled Eros with wings? He didn't know anything but how to paint swallows; on the contrary, he was utterly ignorant of the god's character. For the god is neither light nor easy to throw off when one is carrying the pest, but he is out-and-out heavy. How, then, can such a thing have wings? It's nonsense, no matter if one has said it." And Alexis in Cut Loose: "It is commonly said by the wiseacres that the god Eros cannot fly, but that lovers can; and that he is falsely charged with being winged, and the painters knew nothing about it when they depicted him as having wings."

Εὔβουλος δ' ἢ ᾿Αραρὼς ἐν Καμπυλίωνι·

τίς ἦν ὁ γράψας πρῶτος ἀνθρώπων ἄρα
ἢ κηροπλαστήσας ῎Ερωθ' ὑπόπτερον;
ὡς οὐδὲν ᾔδει πλὴν χελιδόνας γράφειν,
ἀλλ' ἦν ἄπειρος τῶν τρόπων τῶν τοῦ θεοῦ.
ἐστὶν γὰρ οὔτε κοῦφος οὔτε ῥᾀδιος
ἀπαλλαγῆναι τῷ φέροντι τὴν νόσον,
βαρὺς δὲ κομιδῇ. πῶς ἂν οὖν ἔχοι πτερὰ
τοιοῦτο πρᾶγμα; λῆρος, εἰ κἄφησέ τις.

῎Αλεξις δ' ἐν Ἀποκοπτομένῳ·

                      λέγεται γὰρ λόγος
ὑπὸ τῶν σοφιστῶν μὴ πέτεσθαι τὀν θεὸν
τὸν ῎Ερωτα, τοὺς δ' ἐρῶντας· αἰτίαν δ' ἔχειν
ἐκεῖνον ἄλλως, ἠγνοηκότας δὲ τοὺς
γραφεῖς ἔχοντα πτέρυγας αὐτὸν ζωγραφεῖν.