Puts names to all those faces pressed against the glass at night.
Also the host plants, which is nice. Otherwise not much info, but that's understandable considering how many species they had to cram into the book.
One complaint would be that the photo cutouts tend to obscure the fringed edges of many. Another is that, while it reads "Northeastern North America," the range map view stops at Minnesota in the north and Maine in the east. Say what you mean, guys.