America, North: Biospeleology: Figure 2. Rhadine reyesi, a predatory troglobitic beetle that feeds on the eggs of cave crickets. (Photo by Jean Krejca and Steve Taylor, courtesy of Natural Resources Branch, Fort Hood, Texas)

Plateaux, and Edwards Plateau. Aquatic beetles occur in the Edwards Aquifer. The Leiodidae is one of the important cave beetle families, with more than 18 troglobites in the genus Ptomaphagus in the southeastern United States. Much of the cavernicole diversity in the Coleoptera occurs in the Carabidae, with many troglophilic and troglobitic species especially in the genera Pseudanophthalmus which is especially rich in species in the Appalachians and Interior Low Plateaus and Rhadine (Figure 2) which is most diverse in the Edwards Plateau and occurs in caves throughout much of the southwestern United States. Several species of beetles in each of these two genera are closely associated with cave or camel crickets, and prey upon the eggs of those crickets.