Flies are insects of the order Diptera, the name being derived from the Greek δι- di- "two", and πτερόν pteron "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics. Diptera is a large order containing an estimated 1,000,000 species including horse-flies, crane flies, hoverflies, mosquitoes and others, although only about 125,000 species have been described.
The Tachinidae are a large and variable family of true flies within the insect order Diptera, with more than 8,200 known species and many more to be discovered. Over 1,300 species have been described in North America alone. Insects in this family commonly are called tachinid flies or simply tachinids. As far as is known, they all are protelean parasitoids, or occasionally parasites, of arthropods, usually other insects. The family is known from many habitats in all zoogeographical regions and is especially diverse in South America.
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, also 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.
The Nematocera are a suborder of elongated flies with thin, segmented antennae and mostly aquatic larvae. This group is paraphyletic and contains all flies except for species from suborder Brachycera, which includes more commonly known species such as the housefly or the common fruit fly. The equivalent clade to Nematocera is the whole Diptera, with Brachycera as a subclade. Families in Nematocera include mosquitoes, crane flies, gnats, black flies, and multiple families commonly known as midges. The Nematocera typically have fairly long, fine, finely-jointed antennae. In many species, such as most mosquitoes, the female antennae are more or less threadlike, but the males have spectacularly plumose antennae.
The Asilidae are the robber fly family, also called assassin flies. They are powerfully built, bristly flies with a short, stout proboscis enclosing the sharp, sucking hypopharynx. The name "robber flies" reflects their expert predatory habits; they feed mainly or exclusively on other insects and, as a rule, they wait in ambush and catch their prey in flight.
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.
The Platypezoidea are a superfamily of true flies of the section Aschiza. Their closest living relatives are the Syrphoidea, which, for example, contain the hoverflies. Like these, the adults do not burst open their pupal cases with a ptilinum when hatching, thus the Aschiza do not have the inverted-U-shaped suture above the antennae. They are, however, muscomorphs, thus have a particular type of pupal case resembling a rounded barrel and called puparium.
Carnoidea is a superfamily of Acalyptratae flies.
Carnidae, also known as bird flies or filth flies, is a family of flies (Diptera). There are 6 genera, containing about 93 species worldwide.
Bombylius major is a parasitic bee mimic fly. B. major is the most common type of fly within the Bombylius genus. The fly derives its name from its close resemblance to bumblebees and are often mistaken for them.
Carnus hemapterus is a Dipteran insect, a small-bodied and partly black-coloured carnid fly. In their adult stage of life, they are blood-sucking ectoparasites of nestling birds. Within the genus Carnus, this is the only species widespread across Europe and the cold and temperate regions of Asia and North America. Female body length is about 1.5 mm, males are smaller. It typically occurs in the nests of medium- to large-bodied birds, provided that the nest is not on the ground. It is particularly common on the chicks of owls, falcons, rollers, bee-eaters and starlings. Females give birth to larvae that live within the nest and feed on organic debris and the pupae also overwinter there. The emergence of imagines is synchronized to the hatch of host nestlings in the subsequent year. They prefer larger chicks within the nest. Adult flies have a winged and an unwinged variety, the latter being more common. In fact, unwinged flies still carry the basal part of their wings, but the majority of the wing is broken off. Flies live only on the nestlings before and during the development of the plumage, and disappear later on.
Synthesiomyia nudiseta is one of the largest flies in the family Muscidae. The fly has a pair of forewings; the paired hind wings have been reduced to halteres that help with stability and movement during flight. Key characteristics of this species include plumose segmented aristae, well-developed calypters, and sternopleural bristles. Synthesiomyia nudiseta is a forensically important species because it is necrophilous and can therefore help determine the time of colonization for the post mortem interval with its known life cycle.
There are various disparate groups of wingless insects. Apterygota are a subclass of small, agile insects, distinguished from other insects by their lack of wings in the present and in their evolutionary history. They include Thysanura . Some species lacking wings are members of insect orders that generally do have wings. Some do not grow wings at all, having "lost" the possibility in the remote past. Some have reduced wings that are not useful for flying. Some develop wings but shed them after they are no longer useful. Other groups of insects may have castes with wings and castes without, such as ants. Ants have alate queens and males during the mating season and wingless workers, which allows for smaller workers and more populous colonies than comparable winged wasp species.
Braula is a genus of flies (Diptera) in the family Braulidae. These are very unusual flies, wingless and flattened, and barely recognizable as Diptera. Braula coeca Nitzsch is a pest of honey bees. The larvae tunnel through the wax honeycomb and the adults are found on the bodies of honey bees. There is some debate whether the bee louse causes damage to the honey bee. These flies sometimes can be found at places where bees congregate such as flowers or salt licks, waiting to grab onto hosts from uninfested nests. Braula is cosmopolitan and about 1.6 mm in length.
Megabraula is a fly genus in the family Braulidae. These are very unusual flies, wingless and flattened, and barely recognizable as Diptera. Megabraula is found in Nepal and is 3 mm in length. Both species are found in the nests of Apis laboriosa
Dipteran morphology differs in some significant ways from the broader morphology of insects. 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.
Carnus is a genus of flies (Diptera) with 5 described species, all of which are parasites of birds. The adult flies locate a suitable host nest, then shed their wings and feed on the blood of the developing nestlings. Mature female flies lay their eggs in the nest, where their larvae develop on organic detritus.
Braula coeca, the bee louse, is a species of bee louse in the family Braulidae.
Physocephala tibialis is a species of thick-headed fly found throughout the eastern United States, often near flowering plants. The adult fly is primarily black with a yellow face and thin white stripes on the abdomen. It is commonly found along the east coast of the United States and is often found near flowering plants.
