Dear Alexey,
If I had a little more energy this morning I could of course answer this question myself, but let me ask you a bit about Batyushkov. I think I confuse him, God knows why, with Bogdanovich. Who is responsible for the absolutely delightful Dushen'ka? Since you mention Hebe and Zeus, I'll note that this is a re-telling of the Apuleius tale of Cupid and Psyche.
In any event, what were the circumstances of Batyushkov's madness? Nabokov doesn't say.
Tiutchev's reaction to the skylark is interesting. I used to hear meadowlarks when I was growing up and their song, while sung fully perched, was a very beautiful melody, rippling down then quickly back up. I can see how a disturbed soul could interpreted it as almost diabolical laughter. How does a skylark sound (you ought to know!)?
Carolyn