R. Boyle: Googling for VN is very resticted, but there is a sighting on page 133. The Lives of Lepidopterists - Page 133 - Google Books Result

https://books.google.com/books?isbn=3319204572

Lee A. Dyer, ‎Matthew L. Forister - 2015 - ‎Science

Lee A. Dyer, Matthew L. Forister. Chapter. 11. Butterfly. Reflections. in. Thirds. Phil DeVries Preamble

Another reference to VN, accessed through google searches, appears in the introduction: “Another adventurous lepidopterist who I met on that dirt road in Ecuador was Suzanne Rab Green, who works with collections of moths at the American Museum of Natural History (AMNH). When she is not sailing around the world for her “other job,” or sneaking off to a secret high spot that offers the most unique view of New York City, Suzanne can show visiting lepidopterists some very special projects at AMNH, including a large collection of reared tiger moths from the tropics, or a collection of some of Nabokov’s butterflies from one of his long road trips.” ( xi)