Seems to be building up himself nicely with challengers then as soon as he becomes eligible to compete to more ATP events he gets his ass royally royally...back to challengers for some more then back to ATP events and so forth.
That wouldn't qualify as 'vulturing' though, Lorenzi's just a medium/high level Challenger player who actually tries to play ATP events when his ranking allows it. He's not a solid top 100 player really. I don't know but it's just odd to call someone a vulture when he can't even win matches at ATP level consistently. As a matter of fact, kudos to him for actually trying at ATP level when he can get in!