This family includes only about 20 to 25 species, of which most occur in the Palaearctic region. The family is also represented in North America and in Australia (Scoble 1992: 235).
Identification: Agassiz 1985, Gaedike 1974, Gozmány 1955a, Toll 1956, Zagulyaev 1990c.
Nomenclature according to Fauna Europaea.
Species in Belgium: 4.