The Phoridae are a family of small, hump-backed flies resembling fruit flies. Phorid flies can often be identified by their escape habit of running rapidly across a surface rather than taking to the wing. This behaviour is a source of one of their alternate names, scuttle fly. Another vernacular name, coffin fly, refers to Conicera tibialis. About 4,000 species are known in 230 genera. The most well-known species is cosmopolitan Megaselia scalaris. At 0.4 mm in length, the world's smallest fly is the phorid Euryplatea nanaknihali.
The Conopidae, usually known as the thick-headed flies, are a family of flies within the Brachycera suborder of Diptera, and the sole member of the superfamily Conopoidea. Flies of the family Conopidae are distributed worldwide in all the biogeographic realms except for the poles and many of the Pacific islands. About 800 species in 47 genera are described worldwide, about 70 of which are found in North America. The majority of conopids are black and yellow, or black and white, and often strikingly resemble wasps, bees, or flies of the family Syrphidae, themselves notable bee mimics. A conopid is most frequently found at flowers, feeding on nectar with its proboscis, which is often long.
Nycteribiidae is a family of the true fly superfamily Hippoboscoidea are known as "bat flies", together with their close relatives the Streblidae. As the latter do not seem to be a monophyletic group, it is conceivable not to unite all bat flies in a single family.
The Psilidae are family of flies. Commonly called the rust flies, at least 38 species are in four genera. The carrot fly is a member of this group. They are found mainly in the Holarctic.
The Agromyzidae are a family commonly referred to as the leaf-miner flies, for the feeding habits of their larvae, most of which are leaf miners on various plants.
Dolichopodidae, the long-legged flies, are a large, cosmopolitan family of true flies with more than 7,000 described species in about 230 genera. The genus Dolichopus is the most speciose, with some 600 species.
The Limoniinae are a paraphyletic assemblage of genera within the crane flies, Tipulidae, although they can usually be distinguished by the way the wings are held at rest. Limoniines usually hold/fold the wings along the back of the body, whereas other tipulids usually hold them out at right angles. Snow flies such as Chionea scita have no wings at all. Limoniines are also usually smaller than other tipulids, with some exceptions. Limoniinae are a very large assemblage with nearly 10500 described species in 133 genera, and were historically treated as a subfamily, but their classification is in flux; numerous authors recently treated the group at the rank of family, but subsequent phylogenetic analyses revealed that the remaining groups of tipulids render the group paraphyletic. These flies are found in damp places throughout the world, and many species form dense swarms in suitable habitats.
Empididae is a family of flies with over 3,000 described species occurring worldwide in all the biogeographic realms but the majority are found in the Holarctic. They are mainly predatory flies like most of their relatives in the Empidoidea, and exhibit a wide range of forms but are generally small to medium-sized, non-metallic and rather bristly.
The Anisopodidae are a small cosmopolitan family of gnat-like flies known as wood gnats or window-gnats, with 154 described extant species in 15 genera, and several described fossil taxa. Some species are saprophagous or fungivorous. They are mostly small to medium-sized flies, except the genera Olbiogaster and Lobogaster, which are large with bizarrely spatulated abdomens. Their phylogenetic placement is controversial. They have been proposed to be the sister group to the higher flies, the Brachycera. Some authors consider this group to be four distinct families – Anisopodidae, Mycetobiidae, Olbiogastridae, and Valeseguyidae.
The Lonchaeidae are a family of acalyptrate flies commonly known as lance flies. About 500 described species are placed into 9 genera. These are generally small but robustly built flies with blue-black or metallic bodies. They are found, mainly in wooded areas, throughout the world with the exception of polar regions and New Zealand.
The Chamaemyiidae are a small family of acalyptrate flies with less than 200 species described worldwide. The larvae of these small flies are active and predatory and are often used for biological control of aphids, scale insects, and similar pests. Chamaemyiid fossils are poorly represented in amber deposits, but a few examples are known from the Eocene epoch onwards.
The Curtotonidae or quasimodo flies are a small family of small grey to dark brown humpbacked flies (Diptera) with a worldwide distribution, but with very few species in the Nearctic, Australasian/Oceanian, and Palaearctic regions. Most members of the family are found in tropical to subtropical latitudes in Africa and the Neotropics. Many remain undescribed in collections, since little work on the family has been done since the 1930s.
Canacidae, incorrectly Canaceidae, or beach flies, surf or surge flies, is a family of Diptera. There are 113 species in 12 genera. The family now includes Tethininae as a subfamily.
Diastatidae are a family of flies, and are in the order Diptera. They occur primarily in the Holarctic Region, but several species are known from the Oriental, Neotropical, and Australasian regions. Members of the family number over 20 described species in three genera. There is an additional fossil genus.
Platypezidae is a family of true flies of the superfamily Platypezoidea. The more than 250 species are found worldwide primarily in woodland habitats. A common name is flat-footed flies, but this is also used for the closely related Opetiidae which were included in the Platypezidae in former times.
Hybotidae, the typical dance flies, are a family of true flies. They belong to the superfamily Empidoidea and were formerly included in the Empididae as a subfamily.
The Dixidae are a family of aquatic nematoceran flies (Diptera). The larvae live in unpolluted, standing fresh waters, just beneath the surface film, usually amongst marginal aquatic vegetation. They are found in all continents except Antarctica.
The Diptera is a very large and diverse order of mostly small to medium-sized insects. They have prominent compound eyes on a mobile head, and one pair of functional, membraneous wings, which are attached to a complex mesothorax. The second pair of wings, on the metathorax, are reduced to halteres. The order's fundamental peculiarity is its remarkable specialization in terms of wing shape and the morpho-anatomical adaptation of the thorax – features which lend particular agility to its flying forms. The filiform, stylate or aristate antennae correlate with the Nematocera, Brachycera and Cyclorrhapha taxa respectively. It displays substantial morphological uniformity in lower taxa, especially at the level of genus or species. The configuration of integumental bristles is of fundamental importance in their taxonomy, as is wing venation. It displays a complete metamorphosis, or holometabolous development. The larvae are legless, and have head capsules with mandibulate mouthparts in the Nematocera. The larvae of "higher flies" (Brachycera) are however headless and wormlike, and display only three instars. Pupae are obtect in the Nematocera, or coarcate in Brachycera.
Heterocheila is a genus of acalyptrate true flies (Diptera). They are placed in their own family, Heterocheilidae, in the superfamily Sciomyzoidea. They are not widely familiar outside entomological circles, but the common name "half-bridge flies" has been associated with them. They are medium-sized flies occurring mainly in temperate regions on seashores of the Northern Hemisphere, where they and their larvae typically feed on stranded kelp in the wrack zone. In this, they resemble kelp flies, which are members of a different family, though the same superfamily.
Ragadidae is a family of true flies in the superfamily Empidoidea. It was formerly considered a lower taxon, but was published as a new subfamily within Empididae in 2016. Since then, it has been classified as the sister group to Empididae, and has been elevated to family level based on the genetic differences which separate it from Empididae.
