Distribution of the Orphninae
Orphnines are widely distributed in tropical and subtropical regions of southern hemisphere except for Australasia. Six recent regional faunas, separated by different dispersal barriers, can be distinguished.
Afrotropical fauna includes the majority of the species of the genus Orphnus and 3 monotypical genera – Craniorphnus Kolbe, Goniorphnus Arrow, and Hybaloides Quedenfeldt. Orphnines occur throughout the Afrotropical region except for southern Arab Peninsula (where they will probably be found), and south-western part of Southern Africa (arid region of Namaqualand and Namib Desert).
Indo-Malayan fauna is rather poor and not very distinctive. Six species of the genus Orphnus are known from the Hindustan, Sri Lanka Island, and Indo-China. These species are very similar to some African members of Orphnus, and probably their ancestor or ancestors migrated from Africa into Southern Asia not until Miocene.
Mediterranean fauna comprises Hybalus and Chaetonyx Schaum with all species being wingless and having reduced eyes. This fauna is distributed up to Iberian and Balkan peninsulas in the north, but is the most diverse in the Northern Africa.
Madagascan fauna comprises 4 genera (Pseudorphnus Benderitter, Madecorphnus Paulian, Triodontus Westwood, and Renorphnus Frolov et Montreuil) and 30 species. Orphnines are distributed throughout Madagascar except for hyper-arid south-western region; they are not known from Comoro and Mascarene islands.
New World fauna comprises 5 genera (Aegidium Westwood, Aegidiellus Paulian, Aegidinus Arrow, Onorius Frolov et Vaz-de-Mello and Paraegidium Vulcano et. al.,) and 26 species distributed in Caribbean, Guiana, and Amazon biogeographic regions.
Small but distinctive orphnine fauna of São Tomé Island (Gulf of Guinea) comprises a single species of the monotypic genus Stenosternus Karsch.
All regional faunas, except for Indo-Malayan, are highly distinctive and do not share genera or species. Orphnines are absent from Notogea (Australasia), Patagonian Province of Neotropical Realm, Holarctic Realm (except for southern Mediterranean and transitional zone of Sino-Tibetan Mountains), as well as insular part of Indo-Malayan Province.