Late 19th century; earliest use found in American Naturalist. Either from scientific Latin Perlidae, family name (1835 or earlier; from Perla, genus name + -idae; compare earlier Perlariae: see perlarian adjective), or directly from Perla, genus name + -id. With use as noun compare earlier perlarian, and also French perlides, plural noun. With use as adjective compare earlier perlarious, and slightly later perlarian.