Hippoboscoidea is a superfamily of Calyptratae. The flies in this superfamily are blood-feeding obligate parasites of their hosts. Five families are often placed here, though this number actually seems to be off a bit:
The Hippoboscidae are commonly called louse flies. The bat flies are Nycteribiidae and Streblidae; the latter are probably not monophyletic and ought to be either split in two families or united with the Nycteribiidae. The family Glossinidae, monotypic as to genus, contains the tsetse flies, economically important as the vector of trypanosomiasis. The enigmatic Mormotomyiidae is entirely monotypic at present, with the single species Mormotomyia hirsuta known from one locality in Kenya. It might be a distinct offshoot of another family but too little is known about it to be sure.
In older literature, this group is often referred to as the Pupipara ("pupa-bearers"), in reference to the fact that, unlike virtually all other insects, most of the larval development takes place inside the mother's body, and pupation occurs almost immediately after "birth" – in essence, instead of laying eggs a female lays full-size pupae one at a time. In the strict sense, the Pupipara only encompass the Hippoboscidae, Nycteribiidae and "Streblidae", which in older works were all included in Hippoboscidae.