The Acroceridae are a small family of odd-looking flies. They have a hump-backed appearance with a strikingly small head, generally with a long proboscis for accessing nectar. They are rare and not widely known. The most frequently applied common names are small-headed flies or hunch-back flies. Many are bee or wasp mimics. Because they are parasitoids of spiders, they also are sometimes known as spider flies.
Nemestrinoidea is a small, monophyletic superfamily of flies, whose relationship to the other Brachycera is uncertain; they are sometimes grouped with the Tabanomorpha rather than the Asilomorpha. They are presently considered to be the sister taxon to the Asiloidea. The group contains two very small extant families, the Acroceridae and Nemestrinidae, both of which occur worldwide but contain only small numbers of rare species. One extinct family, Rhagionemestriidae, is also included in Nemestrinoidea.
Acrocerinae is a subfamily of small-headed flies in the family Acroceridae. Their larvae are endoparasites of araneomorph spiders, with the exception of Carvalhoa appendiculata which can develop as ectoparasitoids on their host spiders. Traditionally, the subfamily included the genera now placed in Cyrtinae and Ogcodinae, but the subfamily in this sense was found to be polyphyletic and was split up in 2019.
Philopotinae is a subfamily of small-headed flies. They have an arched body shape, as well as enlarged postpronotal lobes that form a collar behind the head. Their larvae are endoparasites of araneomorph spiders in the subgroup Entelegynae.
Panopinae is a subfamily of small-headed flies (Acroceridae). Their larvae are endoparasites of spiders in the infraorder Mygalomorphae.
Acrocera orbiculus, also known as the top-horned hunchback, is a species of fly belonging to the family Acroceridae. The species has a holarctic distribution, ranging from North America to the Palaearctic.
Acrocera is a genus of small-headed flies in the family Acroceridae.
Ogcodes is a cosmopolitan genus of small-headed flies in the family Acroceridae. About 90 species have been described for the genus. It is the most common and speciose genus in its family. These flies are endoparasitoids of ground-dwelling entelegyne spiders.
Eulonchus halli is a species of small-headed flies in the family Acroceridae. It was named after one of its original collectors, Jack C. Hall, who was also a colleague of the species's author, Evert I. Schlinger, at the University of California.
Eulonchus is a genus of small-headed flies in the family Acroceridae. There are six described species in Eulonchus. The genus is found in North America. Adults have a metallic blue, green or sometimes purple coloration, giving them a jewel-like appearance. A common name for flies in the genus is the North American jewelled spider flies. Adults are also known as "sapphires" or "emeralds".
Pterodontia is a genus of small-headed flies. There are at least 20 described species in Pterodontia.
Ocnaea is a genus of small-headed flies. There are 20 described species in Ocnaea.
Lasia is a genus of small-headed flies in the family Acroceridae. There are about 19 described species in Lasia, which are distributed in the New World.
Archocyrtus is an extinct genus of small-headed flies in the family Acroceridae. The genus is known from compression fossils from the Late Jurassic Karabastau Formation of Kazakhstan. The genus is the only member of the subfamily Archocyrtinae.
Archaeterphis is an extinct genus of small-headed flies in the family Acroceridae. It is known from Baltic amber from the Eocene, though the locality is unknown. It contains only one species, Archaeterphis hennigi.
Apsona is a genus of small-headed flies. It contains only one species, Apsona muscaria, which is endemic to New Zealand. It is very similar to the North American species Eulonchus smaragdinus.
Leucopsina is a genus of small-headed flies endemic to Australia. Flies in the genus are colored black and yellow, mimicking the appearance of a wasp. Males and females measure 9.0 mm and 12.0 mm, respectively.
Sabroskya is a genus of small-headed flies in the family Acroceridae. It is known from South Africa and Malawi. It is named after the American entomologist Curtis Williams Sabrosky.
Megalybus is a genus of small-headed flies in the family Acroceridae. It contains three species found in Chile, though two species have also been reported from Neuquén Province of Argentina.
Cyrtinae is a subfamily of the Acroceridae. Their larvae are endoparasites of araneomorph spiders in the subgroup Entelegynae.
