Although caterpillars commonly construct shelters on vegetation that other species subsequently occupy, few studies have focused on the spiders that often recruit to them. Fern moth larvae Herpetogramma theseusalis (Lepidoptera: Crambidae) produce large, roughly circular shelters on ferns that provide them with food and protection. Female jumping spiders Phidippus clarus Keyserling, 1885 (Salticidae) with brood or first-instar young made up over two-thirds of the spiders tallied in a study of abandoned fern moth shelters. The only other species tending young, the sac spider Clubiona bishopi Edwards, 1958 (Clubionidae), made up less than 10% of the total. Only eight species of spiders used these shelters, one-half to one-fourth that of three other studies and differing in the prevalence of jumping spiders, as opposed to a prevalence of sac spiders in the other studies. Although fern moth shelters provide important nest sites for two spiders, these sites did not enhance diversity of the spider community.