From this weekend's Washington Post Magazine, "The Butterfly, Effect," an article on a Red Admiral that meets a stranger in downtown DC and takes up residence with him...
Not surprisingly, there's a brief VN mention:
"I'm convinced that he also had a tremendous sense of joy. The novelist Vladimir Nabokov
picked up on this. A passionate amateur lepidopterist, Nabokov once wrote that the red admiral is 'a most frolicsome fly.' Nabokov also liked to refer to the butterfly as "Red Admirable," a name that according to at least one account was used as far back as the 18th century."
I had always found the butterfly capers near the end of PF a little unlikely (the daily return of the butterfly, the intentional settling on the sleeve to visit, and especially the sliding down the leaf "like a boy down the banisters on his birthday"), but most of it is quite plausible, apparently...