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Schizophora

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36-600: Acalyptratae Calyptratae The Schizophora are a section of true flies containing 78 families, which are collectively referred to as muscoids , although technically the term "muscoid" should be limited to flies in the superfamily Muscoidea ; this is an example of informal, historical usage persisting in the vernacular. The section is divided into two subsections, the Acalyptratae and Calyptratae , which are commonly referred to as acalyptrate muscoids and calyptrate muscoids , respectively. The defining feature of

72-456: A length of up to 7 cm (2.8 in), is generally considered to be the largest fly in the world, while the smallest is Euryplatea nanaknihali , which at 0.4 mm (0.016 in) is smaller than a grain of salt. Brachycera are ecologically very diverse, with many being predatory at the larval stage and some being parasitic. Animals parasitised include molluscs , woodlice , millipedes , insects, mammals , and amphibians . Flies are

108-405: A meal. For visual course control, flies' optic flow field is analyzed by a set of motion-sensitive neurons. A subset of these neurons is thought to be involved in using the optic flow to estimate the parameters of self-motion, such as yaw, roll, and sideward translation. Other neurons are thought to be involved in analyzing the content of the visual scene itself, such as separating figures from

144-401: A mobile head, with a pair of large compound eyes , and mouthparts designed for piercing and sucking (mosquitoes, black flies and robber flies), or for lapping and sucking in the other groups. Their wing arrangement gives them great manoeuvrability in flight, and claws and pads on their feet enable them to cling to smooth surfaces. Flies undergo complete metamorphosis ; the eggs are often laid on

180-604: A subsection of the Schizophora , which are a section of the order Diptera , the "true flies". In various contexts the Acalyptratae also are referred to informally as the acalyptrate muscoids , or acalyptrates , as opposed to the Calyptratae . All forms of the name refer to the lack of calypters in the members of this subsection of flies. An alternative name, Acalypterae is current, though in minority usage. It

216-438: A variety of hosts. The larvae of the shore flies (Ephydridae) and some Chironomidae survive in extreme environments including glaciers ( Diamesa sp., Chironomidae ), hot springs, geysers, saline pools, sulphur pools, septic tanks and even crude oil ( Helaeomyia petrolei ). Adult hoverflies (Syrphidae) are well known for their mimicry and the larvae adopt diverse lifestyles including being inquiline scavengers inside

252-485: Is Spilomyia longicornis , which is a fly but mimics a vespid wasp. Flies have a mobile head with a pair of large compound eyes on the sides of the head, and in most species, three small ocelli on the top. The compound eyes may be close together or widely separated, and in some instances are divided into a dorsal region and a ventral region, perhaps to assist in swarming behaviour. The antennae are well-developed but variable, being thread-like, feathery or comb-like in

288-442: Is likely to change in future. Diptera Housefly (Muscidae) (top left) Haematopota pluvialis (Tabanidae) (top right) Ctenophora pectinicornis (Tipulidae) (mid left) Ochlerotatus notoscriptus (Culicidae) (mid right) Milesia crabroniformis (Syrphidae) (bottom left) Holcocephala fusca (Asilidae) (bottom right) Nematocera ( paraphyletic ) (inc Eudiptera ) Brachycera Flies are insects of

324-547: Is one of the major insect orders and of considerable ecological and human importance. Flies are major pollinators, second only to the bees and their Hymenopteran relatives. Flies may have been among the evolutionarily earliest pollinators responsible for early plant pollination . Fruit flies are used as model organisms in research, but less benignly, mosquitoes are vectors for malaria , dengue , West Nile fever , yellow fever , encephalitis , and other infectious diseases ; and houseflies , commensal with humans all over

360-524: Is widely thought to be a member of Mecopterida , along with Lepidoptera (butterflies and moths), Trichoptera (caddisflies), Siphonaptera (fleas), Mecoptera (scorpionflies) and possibly Strepsiptera (twisted-wing flies). Diptera has been grouped with Siphonaptera and Mecoptera in the Antliophora, but this has not been confirmed by molecular studies. Diptera were traditionally broken down into two suborders, Nematocera and Brachycera , distinguished by

396-514: The Cenozoic , with the first appearance of the group during the early Paleogene , around 53 million years ago, with it being estimated that they split off from other flies around 66-65 million years ago. Acalyptratae Carnoidea Conopoidea Diopsoidea Ephydroidea Lauxanioidea Lonchaeoidea Nerioidea Opomyzoidea Sciomyzoidea Sphaeroceroidea Tephritoidea The Acalyptratae or Acalyptrata are

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432-572: The Jurassic , some 180 million years ago. A third radiation took place among the Schizophora at the start of the Paleogene , 66 million years ago. The phylogenetic position of Diptera has been controversial. The monophyly of holometabolous insects has long been accepted, with the main orders being established as Lepidoptera, Coleoptera, Hymenoptera and Diptera, and it is the relationships between these groups which has caused difficulties. Diptera

468-1071: The Mecopterida , alongside the Mecoptera , Siphonaptera , Lepidoptera and Trichoptera . The possession of a single pair of wings distinguishes most true flies from other insects with "fly" in their names. However, some true flies such as Hippoboscidae (louse flies) have become secondarily wingless. The cladogram represents the current consensus view. Hymenoptera (sawflies, wasps, ants, bees) [REDACTED] Raphidioptera (snakeflies) [REDACTED] Megaloptera (alderflies and allies) [REDACTED] Neuroptera (Lacewings and allies) [REDACTED] Coleoptera (beetles) [REDACTED] Strepsiptera (twisted-wing parasites) [REDACTED] Trichoptera (caddisflies) [REDACTED] Lepidoptera (butterflies, moths) [REDACTED] Diptera [REDACTED] Mecoptera (scorpionflies) [REDACTED] Siphonaptera (fleas) [REDACTED] The first true dipterans known are from

504-666: The Middle Triassic (around 240 million years ago), and they became widespread during the Middle and Late Triassic . Modern flowering plants did not appear until the Cretaceous (around 140 million years ago), so the original dipterans must have had a different source of nutrition other than nectar . Based on the attraction of many modern fly groups to shiny droplets, it has been suggested that they may have fed on honeydew produced by sap-sucking bugs which were abundant at

540-570: 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 more than 150,000 species including horse-flies , crane flies , hoverflies , mosquitoes and others. Flies have

576-548: The thorax , bears the wings and contains the flight muscles on the second segment, which is greatly enlarged; the first and third segments have been reduced to collar-like structures, and the third segment bears the halteres , which help to balance the insect during flight. The third tagma is the abdomen consisting of 11 segments, some of which may be fused, and with the 3 hindmost segments modified for reproduction. Some Dipterans are mimics and can only be distinguished from their models by very careful inspection. An example of this

612-827: The Brachycera includes broader, more robust flies with short antennae. Many nematoceran larvae are aquatic. There are estimated to be a total of about 19,000 species of Diptera in Europe, 22,000 in the Nearctic region, 20,000 in the Afrotropical region, 23,000 in the Oriental region and 19,000 in the Australasian region. While most species have restricted distributions, a few like the housefly ( Musca domestica ) are cosmopolitan. Gauromydas heros ( Asiloidea ), with

648-1403: The Nematocera. The construction of a phylogenetic tree has been the subject of ongoing research. The following cladogram is based on the FLYTREE project. Ptychopteromorpha (phantom and primitive crane-flies) [REDACTED] Culicomorpha (mosquitoes, blackflies and midges) [REDACTED] Blephariceromorpha (net-winged midges, etc) [REDACTED] Bibionomorpha (gnats) [REDACTED] Psychodomorpha (drain flies, sand flies, etc) [REDACTED] Tipulomorpha (crane flies) [REDACTED] Stratiomyomorpha (soldier flies, etc) [REDACTED] Xylophagomorpha (stink flies, etc) [REDACTED] Tabanomorpha (horse flies, snipe flies, etc) [REDACTED] Nemestrinoidea [REDACTED] Asiloidea (robber flies, bee flies, etc) [REDACTED] Empidoidea (dance flies, etc) [REDACTED] Aschiza (in part) Phoroidea (flat-footed flies, etc) [REDACTED] Syrphoidea (hoverflies) [REDACTED] Hippoboscoidea (louse flies, etc) [REDACTED] Muscoidea (house flies, dung flies, etc) [REDACTED] Oestroidea (blow flies, flesh flies, etc) [REDACTED] Acalyptratae (marsh flies, etc) [REDACTED] Flies are often abundant and are found in almost all terrestrial habitats in

684-463: The Schizophora is the presence of a special structure used to help the emerging adult fly break free of the puparium ; this structure is an inflatable membranous sac called the ptilinum that protrudes from the face, above the antennae . The inflation of the ptilinum (using fluid hemolymph rather than air) creates pressure along the line of weakness in the puparium, which then bursts open along

720-519: The antennae and the maxillary palps bear the main olfactory receptors, while the gustatory receptors are in the labium, pharynx, feet, wing margins and female genitalia, enabling flies to taste their food by walking on it. The taste receptors in females at the tip of the abdomen receive information on the suitability of a site for ovipositing. Flies that feed on blood have special sensory structures that can detect infrared emissions, and use them to home in on their hosts, Many blood-sucking flies can detect

756-404: The differences in antennae. The Nematocera are identified by their elongated bodies and many-segmented, often feathery antennae as represented by mosquitoes and crane flies. The Brachycera have rounder bodies and much shorter antennae. Subsequent studies have identified the Nematocera as being non-monophyletic with modern phylogenies placing the Brachycera within grades of groups formerly placed in

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792-431: The different families. The mouthparts are adapted for piercing and sucking, as in the black flies, mosquitoes and robber flies, and for lapping and sucking as in many other groups. Female horse-flies use knife-like mandibles and maxillae to make a cross-shaped incision in the host's skin and then lap up the blood that flows. The gut includes large diverticulae , allowing the insect to store small quantities of liquid after

828-749: The flies, principally in the family Cecidomyiidae (gall midges). Many flies (most importantly in the family Agromyzidae) lay their eggs in the mesophyll tissue of leaves with larvae feeding between the surfaces forming blisters and mines. Some families are mycophagous or fungus feeding. These include the cave dwelling Mycetophilidae (fungus gnats) whose larvae are the only diptera with bioluminescence. The Sciaridae are also fungus feeders. Some plants are pollinated by fungus feeding flies that visit fungus infected male flowers. The larvae of Megaselia scalaris (Phoridae) are almost omnivorous and consume such substances as paint and shoe polish. The Exorista mella (Walker) fly are considered generalists and parasitoids of

864-400: The forms stuck. The Acalyptratae are a large assemblage, exhibiting very diverse habits, with one notable and perhaps surprising exception: no known acalyptrates are obligate blood-feeders ( hematophagous ), though blood feeding at various stages of the life history is common throughout other Dipteran sections. The classification of the Acalyptratae has varied over time, and the below list

900-527: The ground using motion parallax. The H1 neuron is responsible for detecting horizontal motion across the entire visual field of the fly, allowing the fly to generate and guide stabilizing motor corrections midflight with respect to yaw. The ocelli are concerned in the detection of changes in light intensity, enabling the fly to react swiftly to the approach of an object. Like other insects, flies have chemoreceptors that detect smell and taste, and mechanoreceptors that respond to touch. The third segments of

936-431: The larval food-source and the larvae, which lack true limbs, develop in a protected environment, often inside their food source. Other species are ovoviviparous , opportunistically depositing hatched or hatching larvae instead of eggs on carrion , dung, decaying material, or open wounds of mammals. The pupa is a tough capsule from which the adult emerges when ready to do so; flies mostly have short lives as adults. Diptera

972-455: The maternal chorion , two additional membranes develop from embryonic tissue, the amnion and the serosa . This serosa secretes a cuticle rich in chitin that protects the embryo against desiccation. In the Schizophora, however, the serosa does not develop, but these flies lay their eggs in damp places, such as rotting organic matter. The absence of schizophoran flies from Cretaceous rocks implies that they likely rapidly diversified during

1008-419: The nests of social insects. Some brachycerans are agricultural pests, some bite animals and humans and suck their blood, and some transmit diseases. Flies are adapted for aerial movement and typically have short and streamlined bodies. The first tagma of the fly, the head, bears the eyes, the antennae , and the mouthparts (the labrum, labium, mandible, and maxilla make up the mouthparts). The second tagma,

1044-406: The neural ganglia , and concentration of nerve tissue in the thorax, a feature that is most extreme in the highly derived Muscomorpha infraorder. Some flies such as the ectoparasitic Nycteribiidae and Streblidae are exceptional in having lost their wings and become flightless. The only other order of insects bearing a single pair of true, functional wings, in addition to any form of halteres, are

1080-405: The raised concentration of carbon dioxide that occurs near large animals. Some tachinid flies (Ormiinae) which are parasitoids of bush crickets , have sound receptors to help them locate their singing hosts. Diptera have one pair of fore wings on the mesothorax and a pair of halteres , or reduced hind wings, on the metathorax . A further adaptation for flight is the reduction in number of

1116-509: The seam to allow the adult to escape. When the adult emerges, the fluid is withdrawn, the ptilinum collapses, and the membrane retracts entirely back inside the head. The large, inverted, U-shaped suture in the face through which it came, however, is still quite visible, and the name "Schizophora" ("split-bearers") is derived from this ptilinal or frontal suture. The term was first used by Eduard Becher . In contrast to eggs of other arthropods, most insect eggs are drought-resistant, because inside

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1152-568: The second largest group of pollinators after the Hymenoptera (bees, wasps and relatives). In wet and colder environments flies are significantly more important as pollinators. Compared to bees, they need less food as they do not need to provision their young. Many flowers that bear low nectar and those that have evolved trap pollination depend on flies. It is thought that some of the earliest pollinators of plants may have been flies. The greatest diversity of gall forming insects are found among

1188-606: The time, and dipteran mouthparts are well-adapted to softening and lapping up the crusted residues. The basal clades in the Diptera include the Deuterophlebiidae and the enigmatic Nymphomyiidae . Three episodes of evolutionary radiation are thought to have occurred based on the fossil record. Many new species of lower Diptera developed in the Triassic , about 220 million years ago. Many lower Brachycera appeared in

1224-473: The world apart from Antarctica. They include many familiar insects such as house flies, blow flies, mosquitoes, gnats, black flies, midges and fruit flies. More than 150,000 have been formally described and the actual species diversity is much greater, with the flies from many parts of the world yet to be studied intensively. The suborder Nematocera include generally small, slender insects with long antennae such as mosquitoes, gnats, midges and crane-flies, while

1260-607: The world, spread foodborne illnesses . Flies can be annoyances especially in some parts of the world where they can occur in large numbers, buzzing and settling on the skin or eyes to bite or seek fluids. Larger flies such as tsetse flies and screwworms cause significant economic harm to cattle. Blowfly larvae, known as gentles , and other dipteran larvae, known more generally as maggots , are used as fishing bait , as food for carnivorous animals, and in medicine in debridement , to clean wounds . Dipterans are holometabolans , insects that undergo radical metamorphosis. They belong to

1296-525: Was first used by Pierre-Justin-Marie Macquart in 1835 for a section of his tribe Muscides; he used it to refer to all acalyptrates plus scathophagids and phorids , but excluding Conopidae . The confusing forms of the names stem from their first usage; Acalyptratae and Acalyptrata actually are adjectival forms in Neo-Latin . They were coined in the mid 19th century in contexts such as "Muscae Calyptratae and Acalyptratae" and "Diptera Acalyptrata", and

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