Indeed, and despite its proximity to perpetua, it is (as kmp points out) modifying vestigia in the previous line.kmp dixit:also "inrita" is the key word in the passage - the traces of wickedness have been made void (inrita) and this is what releases the Earth from fear.
Vergil is ingenious here with his phrasing; saving inrita for the first word of the next line gives it an additional emphasis. He then follows it with perpetua up to the caesura; although that word is grammatically linked later with formidine, its position here encourages association with inrita - "wiped out forever".
I should have probably included a note for that; thx to QMF for clarifying.QMF dixit:To better clarify what kmp said, heroas is a Greek accusative plural.
The examples you cite are ones I would also classify as bucolic (I can't believe I overlooked Frost); I should probably have said (as you did) that we don't have formal poetic structures associated with rural themes. But then again, we don't have much at all in the way of formal poetic structure anymore outside of academic exercises. It is my general impression that poetry as practiced, say, 100 years ago is dead as a popular artform. I've attended enough poetry slams and listened to enough rap music (some of it quite good) to believe it.Iynx dixit:We may not have formal structures now that we associate with rural themes. But the last hundred years has brought us much excellent English verse that I, at least, would characterise as bucolic.