Bookworm
2 of the 7 encyclopedias on this shelf carry an entry for Bookworm. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
any grub which feeds on the paper of books. The name more especially belongs to the larva of an anobium (anobium pertinax, A. eruditum, etc.), a small coleopterous insect, which is classed among the Death-Watch insects; though the larva of ecophora pseudospictella, a small brown moth, seems to have nearly an equal claim to it. The latter much resembles the anobium, save that it has six legs, while the anobium has none. Most people are familiar with the bookworm's ravages; but the creatures are extremely rare in the United States, especially since so many chemical substances have been introduced into the manufacture of paper. In southern Europe, the book-eating anobium is still common.
Aiton's Encyclopedia (1910)
a name given to the grub of any one of several different beetles. A common bookworm of wide distribution is the grub of a beetle closely allied to the cinnamon-brown death-watch family, including the apple twig borer and the cigarette beetle. Bookworms are especially fond of old leather bindings, which they riddle with holes. A proverbial "bookworm" is a person who "always has his nose in a book," to the presumable extinction of all ability in so-called practical directions. See Paper ; Printing ; Periodical 2026 Editor's Note: Real bookworms remain a menace in old libraries, where conservators now fight them with freezing and controlled atmospheres rather than poison. The figurative sort has softened: once a mild insult for someone useless in practical matters, "bookworm" is now more often said with affection or pride. (Ed: BR 2026-06-03)