The genus Xenotrichobius Wenzel, 1976 is revised using specimens collected in Venezuela and Peru. X. noctilionis Wenzel, 1976 is redescribed including the puparium. The new species, X. linaresi sp. n., differs from type species in size and shape of male genitalia, and longer setae on dorso-lateral connexivum. Xenotrichobius sp., a single female, has 1 pair of macrosetae in the epiproct and Xenotrichobius sp., a single male, characterized by longitudinal median and transverse mesonotal sutures joined, are described. Close relationships among Xenotrichobius, Paradyschiria Speiser, 1900 and Noctiliostrebla Wenzel, 1966 is supposed, due to the structure of male genitalia, the development of proctiger, and the shape of puparium. A key for the species is given.