The Calliphoridae (commonly known as blow flies, blow-flies, carrion flies, bluebottles, greenbottles, or cluster flies) are a family of insects in the order Diptera, with 1,200 known species. The maggot larvae, often used as fishing bait, are known as gentles. The family is known to be polyphyletic, but much remains disputed regarding proper treatment of the constituent taxa, some of which are occasionally accorded family status (e.g., Bengaliidae, Helicoboscidae, Polleniidae, and Rhiniidae).
The name blow fly comes from an older English term for meat that had eggs laid on it, which was said to be fly blown. The first known association of the term "blow" with flies appears in the plays of William Shakespeare: Love's Labour's Lost, The Tempest, and Antony and Cleopatra.
|Male Chrysomya megacephala|
Calliphoridae adults are commonly shiny with metallic colouring, often with blue, green, or black thoraces and abdomens. Antennae are three-segmented and aristate. The arista are plumose the entire length, and the second antennal segment is distinctly grooved. Members of Calliphoridae have branched Rs 2 veins, frontal sutures are present, and calypters are well developed.
The characteristics and arrangement of hairlike bristles are used to tell the difference between members of this family. All blow flies have bristles located on the meron. Having two notopleural bristles and a hindmost posthumeral bristle located lateral to presutural bristle are characteristics to look for when identifying this family.
The thorax has the continuous dorsal suture across the middle, along with well-defined posterior calli. The postscutellum is absent or weakly developed. The costa is unbroken and the subcosta is apparent on the insect.
Most species of blow flies studied thus far are anautogenous; a female requires a substantial amount of protein to develop mature eggs within her ovaries (about 800 µg per pair of ovaries in Phormia regina). The current theory is that females visit carrion both for protein and egg laying, but this remains to be proven. Blow fly eggs, usually yellowish or white in color, are about 1.5 mm x 0.4 mm, and, when laid, look like rice balls. While the female blow fly typically lays 150–200 eggs per batch, she is usually iteroparous, laying around 2,000 eggs during the course of her life. The sex ratio of blow fly eggs is usually 50:50, but one exception is females from two species of the genus Chrysomya (C. rufifacies and C. albiceps), which are either arrhenogenic (laying only male offspring) or thelygenic (laying only female offspring).
Hatching from an egg to the first larval stage takes about eight hours to one day. Larvae have three stages of development (instars); each stage is separated by a molting event. The instars are separable by examining the posterior spiracles, or openings to the breathing system. The larvae use proteolytic enzymes in their excreta (as well as mechanical grinding by mouth hooks) to break down proteins on the livestock or corpse on which they are feeding. Blow flies are poikilothermic – the rate at which they grow and develop is highly dependent on temperature and species. Under room temperature (about 20 °C), the black blow fly Phormia regina can change from egg to pupa in 150–266 hours (six to 11 days). When the third larval stage is complete, it will leave the corpse and burrow into the ground to pupate, emerging as an adult seven to fourteen days later.
Adult blow flies are occasional pollinators, being attracted to flowers with strong odors resembling rotting meat, such as the American pawpaw or dead horse arum. Little doubt remains that these flies use nectar as a source of carbohydrates to fuel flight, but just how and when this happens is unknown. One study showed the visual stimulus a blow fly receives from its compound eyes is responsible for causing its legs to extend from its flight position and allow it to land on any surface.
Larvae of most species are scavengers of carrion and dung, and most likely constitute the majority of the maggots found in such material, although they are not uncommonly found in close association with other dipterous larvae from the families Sarcophagidae and Muscidae, and many other acalyptrate muscoid flies.
Predators of blow flies include: spiders, beetles, frogs, and birds including chickens.
About 1,100 species of blow flies are known, with 228 species in the Neotropics, and a large number of species in Africa and Southern Europe.
The typical habitats for blow flies are temperate to tropical areas that provide a layer of loose, damp soil and litter where larvae may thrive and pupate.
Blow flies have caught the interest of researchers in a variety of fields, although the large body of literature on calliphorids has been concentrated on solving the problem of myiasis in livestock. The sheep blow fly Lucilia cuprina causes the Australian sheep industry an estimated AU$170 million a year in losses.
The most common causes of myiasis in humans and animals are the three dipteran families Oestridae, Calliphoridae, and Sarcophagidae. Myiasis in humans is clinically categorized in six ways: dermal and subdermal, facial cavity, wound or traumatic, gastrointestinal, vaginal, and generalized. If found in humans, the dipteran larvae are usually in their first instar. The only treatment necessary is just to remove the maggots, and the patient heals naturally. Whilst not strictly a myiasis species, the Congo floor maggot feeds on mammal blood, occasionally human.
The New World primary screwworm (Cochliomyia hominivorax), once a major pest in southern United States, has been eradicated from the United States, Mexico and Central America through an extensive release program by the USDA of sterilized males. The USDA maintains a sterile screwworm fly production plant and release program in the eastern half of the Republic of Panama to keep fertile screwworms from migrating north. Currently, this species is limited to lowland tropical countries in South America and some Caribbean islands.
The Old World primary screwworm (Chrysomya bezziana) is an obligate parasite of mammals. This fly is distributed throughout the Old World, including Southeast Asia, tropical and subtropical Africa, some countries in the Middle East, India, the Malay Peninsula, the Indonesian and Philippine Islands, and Papua New Guinea.
The secondary screwworm (Cochliomyia macellaria) has become one of the principal species on which to base post-mortem interval estimations because its succession and occurrence on decomposing remains has been well defined. The secondary screwworm is found throughout the United States, the American tropics, and in southern Canada during summer months. This species is one of the most common species found on decomposing remains in the southern United States.
Maggot debridement therapy (MDT) is the medical use of selected, laboratory-raised fly larvae for cleaning nonhealing wounds. Medicinal maggots perform debridement by selectively eating only dead tissue. Lucilia sericata (Phaenicia sericata), or the common green bottlefly, is the preferred species used in maggot therapy. MDT can be used to treat pressure ulcers, diabetic foot wounds, venous stasis ulcers, and postsurgical wounds.
Adults may be vectors of pathogens of diseases such as dysentery. Flies, most commonly Calliphoridae, have frequently been associated with disease transmission in humans and animals, as well as myiasis. Studies and research have linked Calliphora and Lucilia to vectors of causal agents of bacterial infections. These larvae, commonly seen on decaying bodies, feed on carrion while the adults can be necrophagous or vegetative. During the process of decay, microorganisms (e.g. Mycobacterium) may be released through the body. Flies arrive at the scene and lay their eggs. The larvae begin eating and breaking down the corpse, simultaneously ingesting these organisms which is the first step of one transmission route.
Other potential and threatening diseases include rabbit haemorrhagic disease in New Zealand and flystrike. Although strike is not limited to blow flies, these maggots are a major source of this skin invasion, causing lesions, which, if severe enough, may be lethal. Strike starts when blow flies lay eggs in a wound or fecal material present on the sheep. When the maggots hatch, they begin feeding on the sheep and thus irritating it. As soon as the first wave of maggots hatch, they attract more blow flies, causing the strike. Insecticides are available for blow fly prevention, and precautionary measures may be taken, such as docking tails, shearing, and keeping the sheep healthy overall.
Salmonellosis has also been proven to be transmitted by the blow fly through saliva, feces and direct contact by the flies' tarsi. Adult flies may be able to spread pathogens via their sponging mouthparts, vomit, intestinal tract, sticky pads of their feet, or even their body or leg hairs.
As the flies are vectors of many diseases, the importance of identifying the transmissible agents, the route of transmission, and prevention and treatments in the event of contact are becoming increasingly important. With the ability to lay hundreds of eggs in a lifetime and the presence of thousands of larvae at a time in such close proximity, the potential for transmission is high, especially at ideal temperatures.
Blow flies are usually the first insects to come in contact with carrion because they have the ability to smell dead animal matter from up to 1 mile (1.6 km) away. Upon reaching the carrion, females deposit eggs on it. Since development is highly predictable if the ambient temperature is known, blow flies are considered a valuable tool in forensic science. Blow flies are used forensically to estimate the PMImin (minimum post-mortem interval) for human corpses. Traditional estimations of time since death are generally unreliable after 72 hours and often entomologists are the only officials capable of generating an accurate approximate time interval. The specialized discipline related to this practice is known as forensic entomology.
In addition to being used to estimate the minimum post-mortem interval (PMImin), assuming colonization occurred after death, blow fly specimens found infesting a human corpse are used to determine if the corpse was relocated or if the individual ingested narcotics prior to death.
Calliphora vicina and Cynomya mortuorum are important flies of forensic entomology. Other forensically important Calliphoridae are Phormia regina, Calliphora vomitoria, Calliphora livida, Lucilia cuprina, Lucilia sericata, Lucilia illustris, Chrysomya rufifacies, Chrysomya megacephala, Cochliomyia macellaria, and Protophormia terraenovae. One myth states that species from the genus Lucilia can sense death and show up right before it even occurs.
Bengalia is a genus of blow flies in the family Calliphoridae with one authority considering the genus to belong to a separate family Bengaliidae. These bristly and, unlike the greens and blues of most calliphorids, dull coloured flies, are especially noted for their relationship to ants. Little is known of their biology and life-cycle, although adults of many species are kleptoparasitic on ants and will snatch food and pupae being carried by ants or feed on winged termites.
The apt name “Highwayman Fly” was given by an early observer of their way of robbing ants.
Very little is known about their breeding habits. The genus is found in the Afrotropical and oriental region with one species from Australia possibly a recent introduction.Blue bottle fly
The bluebottle fly or bottlebee (Calliphora vomitoria) is a common blow fly belonging to the family Calliphoridae. Calliphora vomitoria is the type species for the genus Calliphora.Calliphora
Calliphora is the type genus of blow flies, the family Calliphoridae.Calliphora vicina
Calliphora vicina is a member of the family Calliphoridae, which includes blow flies and bottle flies. These flies are important in the field of forensic entomology. C. vicina is currently one of the most entomologically important fly species because of its consistent time of arrival and colonization of the body following death.Calliphorinae
The Calliphorinae are a subfamily of the blow flies family Calliphoridae. The distinguishing characteristics of this subfamily are: the stem vein is bare, the lower calypter and the proepisternal depression are bristly, but the suprasquamal region is bare or with only a few random bristles. The thorax is dull and bears fine hairs, and the abdomen is usually colored shining blue.The Bengaliinae (which have more yellowish and dull abdomens) are usually included herein, as are the Luciliinae and Polleniinae in older treatments. The latter two are more often considered separate subfamilies in recent works.Chrysomya albiceps
Chrysomya albiceps is a species belonging to the blow fly family, Calliphoridae.Chrysomya megacephala
Chrysomya megacephala, more commonly known as the oriental latrine fly, is a member of the family Calliphoridae (blowflies). It is a warm-weather fly with a greenish-blue metallic box-like body. The fly infests corpses soon after death, making it important to forensic science. This fly is implicated in some public health issues; it can cause accidental myiasis, and also infects fish and livestock.Chrysomyinae
The Chrysomyinae are a subfamily of Calliphoridae, or blow flies. According to Keys of the Genera and Species of Blow Flies (Diptera: Calliphoridae) of America North of Mexico by Terry Whitworth, the distinguishing characteristic of this subfamily is a setose stem vein (Whitworth, 709). This subfamily includes the genera Chloroprocta, Cochliomyia, Chrysomya, Campsomyiops, Phormia, Protocalliphora, Protophormia, and Trypocalliphora.Cochliomyia
Cochliomyia is a genus in the family Calliphoridae, known as blowflies, in the order Diptera. Cochliomyia is commonly referred to as the New World screwworm flies, as distinct from Old World screwworm flies. Four species are in this genus: C. macellaria, C. hominivorax, C. aldrichi, and C. minima.C. hominivorax is known as the primary screwworm because its larvae produce myiasis and feed on living tissue. This feeding causes deep, pocket-like lesions in the skin, which can be very damaging to the animal host. C. macellaria is known as the secondary screwworm because its larvae produce myiasis, but feed only on necrotic tissue. Both C. hominivorax and C. macellaria thrive in warm, tropical areas.Cochliomyia hominivorax
Cochliomyia hominivorax, the New World screw-worm fly, or screw-worm for short, is a species of parasitic fly that is well known for the way in which its larvae (maggots) eat the living tissue of warm-blooded animals. It is present in the New World tropics. There are five species of Cochliomyia but only one species of screw-worm fly in the genus; there is also a single Old World species in a different genus (Chrysomya bezziana). Infestation of a live vertebrate animal by a maggot is technically called myiasis. While the maggots of many fly species eat dead flesh, and may occasionally infest an old and putrid wound, screw-worm maggots are unusual because they attack healthy tissue.Cordylobia anthropophaga
Cordylobia anthropophaga, the mango fly, tumbu fly, tumba fly, putzi fly, or skin maggot fly, is a species of blow-fly common in East and Central Africa. It is a parasite of large mammals (including humans) during its larval stage. C. anthropophaga has been endemic in the subtropics of Africa for more than 135 years and is a common cause of myiasis in humans in the region.Its specific epithet anthropophaga derives from the Greek word anthropophagos, "human eater".
The mode of infection by the Cayor Worm. Doctors Rodhain and Bequaert conclude, from their observations in the Congo Free State, that Cordylobia anthropophaga (Grunberg) lays its eggs on the ground. The larvae, known generally as Cayor Worms, crawl over the soil until they come in contact with a mammal, penetrate the skin and lie in the subcutaneous tissue, causing the formation of tumors. On reaching full growth, the larvae leave the host, fall to the ground, bury themselves and then pupate. This fly is said to be the most common cause of human or animal myiasis in tropical Africa, from Senegal to Natal. In the region of Lower Katanga where these investigations were made, dogs appeared to be the principal hosts, although Cordylobia larvae were found also in guinea-pigs, a monkey, and two humans. The larvae are always localized on those parts of the hosts which come in immediate contact with the soil."
— Ann. Soc. Entom. de Belgique, Iv, pp. 192–197, 1911) summary translation in Entomological News. 1911 Vol. xxii:467.Green bottle fly
The name green bottle fly or greenbottle fly is applied to numerous species of Calliphoridae or blow fly, in the genera Lucilia and Phaenicia (the latter is sometimes considered a subgenus of the former).Lucilia (fly)
Lucilia is a genus of blow flies, in the family Calliphoridae. Various species in this genus are commonly known as "green bottle flies".Lucilia bufonivora
Lucilia bufonivora is a member of the fly family Calliphoridae which are commonly known as blow flies. L. bufonivora is commonly referred to as a toadfly. The adult flies will typically feed on pollen and nectar of flowers, while the larvae are parasitoids that feed mainly on the living flesh of the common toad (Bufo bufo), leading to the toad's death, though they have been found as parasites on other frog and toad species. It is common in north west Europe.Lucilia cuprina
The species Lucilia cuprina, formerly named Phaenicia cuprina, is more commonly known as the Australian sheep blowfly.
Lucilia cuprina also causes the condition known as 'sheep strike'. The female fly locates a sheep with an open wound in which she lays her eggs. The emerging larvae cause large lesions on the sheep, which may prove to be fatal.Oestroidea
Oestroidea is a superfamily of Calyptratae including the blow flies, bot flies, flesh flies, and their relatives.The superfamily includes the families:
Mesembrinellidae (formerly included in Calliphoridae)
Rhiniidae (formerly included in Calliphoridae)
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a mode of reproduction in animals in which embryos that develop inside eggs remain in the mother's body until they are ready to hatch. This method of reproduction is similar to viviparity, but the embryos have no placental connection with the mother and generally receive their nourishment from a yolk sac. In some species, yolk sac supplies are supplemented, or largely replaced by, uterine secretions or other maternal provisioning. Examples include trophic eggs in the uterus, or even intrauterine cannibalism.
Extreme examples of intrauterine secretions occur in some species of insects; for instance, females of some Glossinidae, Hippoboscidae and other Hippoboscoidea retain one larva at a time in the uterus, where it feeds on intrauterine secretions analogous to "milk". When the young insect has completed its larval metamorphosis, the mother deposits it where it can dig in and pupate without further attention. She then proceeds to raise the next larva in the uterus.
The young of some ovoviviparous amphibians such as Limnonectes larvaepartus, are born as larvae, and undergo further metamorphosis outside the body of the mother. Members of genera Nectophrynoides and Eleutherodactylus bear froglets, not only the hatching, but all the most conspicuous metamorphosis, being completed inside the body of the mother before birth.
Among insects that depend on opportunistic exploitation of transient food sources, such as many Sarcophagidae and other carrion flies, and species such as many Calliphoridae, that rely on fresh dung, and parasitoids such as tachinid flies that depend on entering the host as soon as possible, the embryos commonly develop to the first larval instar inside the mother's reproductive tract, and they hatch just before being laid or almost immediately afterwards.Phormia regina
The species Phormia regina, more commonly known as the black blow fly, belongs to the blow fly family Calliphoridae.
Wings of this fly are specialized having a sharp bend halfway through the wing and they are also known to have a well-developed calypter. Blow flies are about the size of a house fly or a little larger, many are metallic blue or green. Key characteristics of this species include black gena, mostly white calypteres and anterior thoracic spiracles that appear to be orange yellow due to being surrounded by bright orange setae.Rhinophoridae
Rhinophoridae is a family of flies (Diptera) found in all zoogeographic regions except Australasia and Oceania, but mainly in the Palaearctic and Afrotropical regions.
They are small, slender, black, bristly flies phylogenetically close to the Tachinidae, although some authors consider them a sister group of te Calliphoridae. The larvae are mostly parasitoids of woodlice, beetles, spiders, and other arthropods, and occasionally snails.
By 2014, about 23 genera were placed in the family, with a total of about 150 species. More are being described occasionally.Genera include:
Acompomintho Villeneuve, 1927
Alvamaja Rognes, 2010
Axinia Colless, 1994
Azaisia Villeneuve, 1930
Baniassa Kugler, 1978
Bezzimyia Townsend, 1919
Macrotarsina Schiner, 1857
Melanophora Meigen, 1803
Oplisa Róndani, 1862
Paykullia Robineau-Desvoidy, 1830
Phyto Robineau-Desvoidy, 1830
Rhinomorinia Brauer & von Bergenstamm, 1889
Rhinophora Robineau-Desvoidy, 1830
Shannoniella Townsend, 1939
Stevenia Robineau-Desvoidy, 1830
Styloneuria Brauer & von Bergenstamm, 1891
Tricogena Róndani, 1856
Tromodesia Róndani, 1856
Extant Diptera families