Chrysomya rufifacies
Encyclopedia
Chrysomya rufifacies is a species belonging to the blow fly family, Calliphoridae, and is most significant in the field of forensic entomology
due to its use in establishing or altering postmortem intervals. The common name for the species is the hairy maggot blow fly, and it belongs to the genus Chrysomya
, which is commonly referred to as the Old World screw-worms. This genus includes other species such as Chrysomya putoria
and Chrysomya bezziana
, which are agents of myiasis
. Chrysomya rufifacies prefers very warm weather and has a relatively short life cycle. It is widely distributed geographically and prefers to colonize large carcasses over small ones. The species commonly has a greenish metallic appearance and is important medically, economically, and forensically.
. Its specific epithet is derived from the Latin
words rufus 'reddish' and facies 'face'. Some taxonomists believe C. rufifacies is conspecific with Chrysomya albiceps
due to biological, ecological, distributional and morphological similarities. The larvae of both species are very difficult to distinguish, and there is only a minor difference between the imagines
. A prostigmatic
bristle is said to be present in C. albiceps and absent in C. rufifacies but it is not present in all albipes or it is very reduced so this character is unreliable. The status of C. rufifacies is not completely clear, and its relation to C. albiceps has not been fully determined.
spiracle
that is pale in color. The mature adult is about 6 millimetre (0.236220472440945 in) – 12 millimetre (0.47244094488189 in) in length.
The use of a microscope
allows the investigator to identify setae on the fly's meron
, a greater ampulla
with stiff erect setae, black first and second abdominal tergites, and a black posterior margin of the third and fourth abdominal tergites. These features are characteristic of the genus Chrysomya. The differentiation between megacephala and rufifacies is accomplished by observing the anterior thoracic spiracle color. Chrysomya rufifacies has a pale or white anterior thoracic spiracle, while Chrysomya megacephala has a dark brown or dark orange anterior thoracic spiracle. Also, Chrysomya rufifacies contains three faint pronotal (pronotum) thoracic stripes which are not readily
visible.
s running down their bodies, and the mature larva is about 14 millimetre (0.551181102362205 in) in length with a dirty yellowish color; hence the common name, hairy maggot blow fly. The peritreme of the posterior spiracle is very wide with a narrow gap that contains forked edges; the slits are short and wide, almost filling the plate.
l, pupa
l, and adult stages. The entire life cycle involving development from egg to adult takes from 190 to 598 hours depending on temperature.
The female lays an average of 210 eggs and a recorded maximum of 368 eggs near fresh corpses and often during daylight hours. After the eggs have been laid, the first instar
larva of the insect emerges from the egg after approximately 26 hours at a temperature of 29° C. A total of three larval instars are involved in the life cycle of the species, and the entire larval development stage takes 2.5 days at a temperature of 29°C. The larvae are capable of regulating their body temperature by moving to a different position in the maggot mass in order to maintain a preferred developmental temperature. The maximal preferential temperature for the larvae of Chrysomya rufifacies is 35.1°C. The developmental time of the species is highly dependent upon temperature due to the cold-blooded nature of insects and the number of accumulated degree day
s. Any variability in developmental times can also be due to different rearing temperatures under different conditions such as varying humidity, rearing media, and larval density.
A pre-pupal stage is often present and characterized by larval dispersion and migration away from the food source in search of a pupation site. The body length of the larva decreases during this stage in preparation for pupation. If the larvae are restricted from movement and not allowed to disperse during the pre-pupal stage, a 24-hour delay in pupation will be observed. Thus, in medicocriminal investigations, if a corpse is wrapped and causes restriction of maggot migration, altered developmental times should be considered. The pre-pupal stage takes 1.5 days and the pupal stage takes 3 days at a temperature of 29°C. Pupation usually occurs near the soil surface or near decaying flesh, and the skin of the larvae harden to form a dark brown puparium or outer casing. Adults emerge after pupation and mate 3–7 days after emergence in summer, and 9–10 days after emergence in autumn. Adults are capable of living for 23–30 days and oviposition
occurs approximately five days after mating.
to treat patients with osteomyelitis
, a microbial infection of the bone C. rufifacies can be a vector for enteric pathogens in countries such as India and Australia
, specifically, if it intrudes homes due to its attraction to feces, fruits, meats, and refuse. Multiple pathogens such as Bacillus bacteria, roundworm, and pinworm have been recovered from the alimentary canal and feces of C. rufifacies. The late instars of the species are beneficial medically by acting as predators of maggots of pathogen-transmitting and myiasis
-producing flies; thus, the larvae can be used as beneficial and effective biological control agents. However, certain strains from Australia, India, and Hawaii have been documented to have instars that are harmful when involved in secondary myiasis.
n species. It is beneficial to humans due to its facultatively predacious nature, in which it consumes maggots of other species, especially competitors on necrotic tissue. The species is known to control populations of Lucilia cuprina
and Lucilia sericata, a dipteran species that arrives first on a dead or rotten body. C. rufifacies can also behave cannibalistically when no other food source is present.
Although a report had been made in 1982 of a case in Hidalgo County, Texas
, where myiasis had been discovered in a dog, Chrysomya rufifacies tends to primarily affect livestock. In many countries, especially Australia, C. rufifacies maggots are known to cause skin and underlying tissue damage of sheep; this processes is known as “sheep strike” and results in economic loss. Typically, economic damage inflicted by C. rufifacies maggots occurs as cutaneous myiasis on ovine livestock. Periodic oviposits on improperly cleaned newborn calves as well as myiasis of mature cattle and sheep have been reported in Texas and Arizona, where the fly has established resident populations. Animal myiasis caused by the species often produces large wounds that heal very slowly; however, this blow fly is not considered as a significant myiasis fly and is rarely involved in myiasis. Although the economic damage inflicted by the fly is unknown, estimates depend on the quality of livestock care and the size of the fly population.
, which occurs when the second instar larvae consume the first instar larvae.
In the southeastern, central, and southwestern part of the United States the adult C. rufifacies is one of the first insects to arrive on a fresh corpse. The adults normally arrive within the first ten minutes after death. The larvae also have a shorter developmental time than other species, but because of their predaceous nature they can also alter entomological based postmortem interval estimation. In Texas and Florida, the species emerges from corpses that are in an advanced stage of decomposition.
macellaria species and may cause the latter species to become extinct. The fly has been successful in competing with other species in many regions of the world. This newly achieved success will require close monitoring of the species in order to examine its ecological effects and determine any serious involvement in myiasis. Further research in the developmental and successional behavior of the species will allow for more accurate postmortem interval calculations in relation to the field of medicocriminal entomology.
Forensic entomology
Forensic entomology is the application and study of insect and other arthropod biology to criminal matters. It is primarily associated with death investigations; however, it may also be used to detect drugs and poisons, determine the location of an incident, and find the presence and time of the...
due to its use in establishing or altering postmortem intervals. The common name for the species is the hairy maggot blow fly, and it belongs to the genus Chrysomya
Chrysomya
Chrysomya is an Old World blow fly genus belonging to the family Calliphoridae. The Chrysomya genus contains a number of species including Chrysomya rufifacies and Chrysomya megacephala...
, which is commonly referred to as the Old World screw-worms. This genus includes other species such as Chrysomya putoria
Chrysomya putoria
Chrysomya putoria, an Old World screw-worm fly, or screw-worm for short, is a species of parasitic fly lay larvae in the living tissue of warm-blooded animals....
and Chrysomya bezziana
Chrysomya bezziana
Chrysomya bezziana, also known as the Old World screwworm fly or screwworm, is an obligate parasite of mammals. Obligate parasitic flies require a host to complete their development. Named to honor the Italian entomologist Mario Bezzi, this fly is widely distributed in Asia, tropical Africa, India,...
, which are agents of myiasis
Myiasis
Myiasis is a general term for infection by parasitic fly larvae feeding on the host's necrotic or living tissue. Colloquialisms for myiasis include flystrike, blowfly strike, and fly-blown. In Greek, "myia" means fly....
. Chrysomya rufifacies prefers very warm weather and has a relatively short life cycle. It is widely distributed geographically and prefers to colonize large carcasses over small ones. The species commonly has a greenish metallic appearance and is important medically, economically, and forensically.
Taxonomy
Chrysomya rufifacies was first described by the French entomologist MacquartJustin Pierre Marie Macquart
Justin Pierre Marie Macquart was a French entomologist specialising in the study of Diptera. He worked on world species as well as European and described many new species.-Early years:...
. Its specific epithet is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
words rufus 'reddish' and facies 'face'. Some taxonomists believe C. rufifacies is conspecific with Chrysomya albiceps
Chrysomya albiceps
Chrysomya albiceps is a species belonging to the blow fly family, Calliphoridae. It is of great medical and sanitary importance, being associated with myiasis in Africa and America although it plays a more significant role as a predator of other dipteran larvae...
due to biological, ecological, distributional and morphological similarities. The larvae of both species are very difficult to distinguish, and there is only a minor difference between the imagines
Imago
In biology, the imago is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis, or after emergence from the pupa where the metamorphosis is complete...
. A prostigmatic
Prostigma (Diptera)
The Prostigma , Stigma Anteriore or Anterior Spiracle is the anterior of the two pairs of spiracles opening on the pleura. The mesothoracic pair is located between the pro- and mesothorax and the metathoracic pair between the meso- and metathothorax...
bristle is said to be present in C. albiceps and absent in C. rufifacies but it is not present in all albipes or it is very reduced so this character is unreliable. The status of C. rufifacies is not completely clear, and its relation to C. albiceps has not been fully determined.
Adult
The hairy maggot blow fly can be readily identified by examining for a shiny metallic blue-green color, a pale genal dilation, and a vestiture of the anterior thoracicThorax (insect anatomy)
The thorax is the mid section of the insect body. It holds the head, legs, wings and abdomen. It is also called mesosoma in other arthropods....
spiracle
Spiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
that is pale in color. The mature adult is about 6 millimetre (0.236220472440945 in) – 12 millimetre (0.47244094488189 in) in length.
The use of a microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
allows the investigator to identify setae on the fly's meron
Meron
A meron or half-instanton is a Euclidean space-time solution of the Yang-Mills field equations. It is a singular non-self-dual solution of topological charge 1/2. The instanton is believed to be composed of two merons....
, a greater ampulla
Ampulla
An ampulla was, in Ancient Rome, a "small nearly globular flask or bottle, with two handles" . The word is used of these in archaeology, and of later flasks, often handle-less and much flatter, for holy water or holy oil in the Middle Ages....
with stiff erect setae, black first and second abdominal tergites, and a black posterior margin of the third and fourth abdominal tergites. These features are characteristic of the genus Chrysomya. The differentiation between megacephala and rufifacies is accomplished by observing the anterior thoracic spiracle color. Chrysomya rufifacies has a pale or white anterior thoracic spiracle, while Chrysomya megacephala has a dark brown or dark orange anterior thoracic spiracle. Also, Chrysomya rufifacies contains three faint pronotal (pronotum) thoracic stripes which are not readily
visible.
Larvae
The larvae of Chrysomya rufifacies are very easily identified with sharp fleshy tubercleTubercle
A tubercle is generally a wart-like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to....
s running down their bodies, and the mature larva is about 14 millimetre (0.551181102362205 in) in length with a dirty yellowish color; hence the common name, hairy maggot blow fly. The peritreme of the posterior spiracle is very wide with a narrow gap that contains forked edges; the slits are short and wide, almost filling the plate.
Life cycle
Knowledge of the life cycle of Chrysomya rufifacies is crucial in determining the postmortem interval for applications related to medicocriminal entomology. Accurate developmental and successional data for the species can significantly aid in legal investigations. Chrysomya rufifacies is especially important in postmortem interval determinations due to its highly predictable developmental time and low degree of variation in larval development. The life cycle of Chrysomya rufifacies is characterized by holometabolous development, consisting of egg, larvaLarva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
l, pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
l, and adult stages. The entire life cycle involving development from egg to adult takes from 190 to 598 hours depending on temperature.
The female lays an average of 210 eggs and a recorded maximum of 368 eggs near fresh corpses and often during daylight hours. After the eggs have been laid, the first instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
larva of the insect emerges from the egg after approximately 26 hours at a temperature of 29° C. A total of three larval instars are involved in the life cycle of the species, and the entire larval development stage takes 2.5 days at a temperature of 29°C. The larvae are capable of regulating their body temperature by moving to a different position in the maggot mass in order to maintain a preferred developmental temperature. The maximal preferential temperature for the larvae of Chrysomya rufifacies is 35.1°C. The developmental time of the species is highly dependent upon temperature due to the cold-blooded nature of insects and the number of accumulated degree day
Degree day
A degree day is a measure of heating or cooling. Totalized degree days from an appropriate starting date are used to plan the planting of crops and management of pests and pest control timing...
s. Any variability in developmental times can also be due to different rearing temperatures under different conditions such as varying humidity, rearing media, and larval density.
A pre-pupal stage is often present and characterized by larval dispersion and migration away from the food source in search of a pupation site. The body length of the larva decreases during this stage in preparation for pupation. If the larvae are restricted from movement and not allowed to disperse during the pre-pupal stage, a 24-hour delay in pupation will be observed. Thus, in medicocriminal investigations, if a corpse is wrapped and causes restriction of maggot migration, altered developmental times should be considered. The pre-pupal stage takes 1.5 days and the pupal stage takes 3 days at a temperature of 29°C. Pupation usually occurs near the soil surface or near decaying flesh, and the skin of the larvae harden to form a dark brown puparium or outer casing. Adults emerge after pupation and mate 3–7 days after emergence in summer, and 9–10 days after emergence in autumn. Adults are capable of living for 23–30 days and oviposition
Oviposition
Oviposition is the process of laying eggs by oviparous animals.Some arthropods, for example, lay their eggs with an organ called the ovipositor.Fish , amphibians, reptiles, birds and monetremata also lay eggs....
occurs approximately five days after mating.
Medical
Chrysomya rufifacies has been used successfully in maggot therapyMaggot therapy
Maggot therapy is a type of biotherapy involving the intentional introduction of live, disinfected maggots into the non-healing skin and soft tissue wound of a human or animal for the purpose of cleaning out the...
to treat patients with osteomyelitis
Osteomyelitis
Osteomyelitis simply means an infection of the bone or bone marrow...
, a microbial infection of the bone C. rufifacies can be a vector for enteric pathogens in countries such as India and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, specifically, if it intrudes homes due to its attraction to feces, fruits, meats, and refuse. Multiple pathogens such as Bacillus bacteria, roundworm, and pinworm have been recovered from the alimentary canal and feces of C. rufifacies. The late instars of the species are beneficial medically by acting as predators of maggots of pathogen-transmitting and myiasis
Myiasis
Myiasis is a general term for infection by parasitic fly larvae feeding on the host's necrotic or living tissue. Colloquialisms for myiasis include flystrike, blowfly strike, and fly-blown. In Greek, "myia" means fly....
-producing flies; thus, the larvae can be used as beneficial and effective biological control agents. However, certain strains from Australia, India, and Hawaii have been documented to have instars that are harmful when involved in secondary myiasis.
Economic
As a species that is widely distributed around the world, Chrysomya rufifacies has a profound impact on both livestock and population of other dipteraDiptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
n species. It is beneficial to humans due to its facultatively predacious nature, in which it consumes maggots of other species, especially competitors on necrotic tissue. The species is known to control populations of Lucilia cuprina
Lucilia cuprina
The species Lucilia cuprina, formerly named Phaenicia cuprina, is more commonly known as the Australian sheep blowfly. It belongs to the blow-fly family Calliphoridae, and while some authorities combine the blow flies and the flesh flies together into the Metopiidae family, distinguishable...
and Lucilia sericata, a dipteran species that arrives first on a dead or rotten body. C. rufifacies can also behave cannibalistically when no other food source is present.
Although a report had been made in 1982 of a case in Hidalgo County, Texas
Hidalgo County, Texas
Hidalgo County is a county located in the U.S. state of Texas. Located in the Rio Grande Valley of South Texas, Hidalgo County is one of the fastest-growing counties in the United States, and is the seventh most-populous county in Texas. Its population in 2010 was 774,769, a 35% increase from 2000...
, where myiasis had been discovered in a dog, Chrysomya rufifacies tends to primarily affect livestock. In many countries, especially Australia, C. rufifacies maggots are known to cause skin and underlying tissue damage of sheep; this processes is known as “sheep strike” and results in economic loss. Typically, economic damage inflicted by C. rufifacies maggots occurs as cutaneous myiasis on ovine livestock. Periodic oviposits on improperly cleaned newborn calves as well as myiasis of mature cattle and sheep have been reported in Texas and Arizona, where the fly has established resident populations. Animal myiasis caused by the species often produces large wounds that heal very slowly; however, this blow fly is not considered as a significant myiasis fly and is rarely involved in myiasis. Although the economic damage inflicted by the fly is unknown, estimates depend on the quality of livestock care and the size of the fly population.
Forensic
Chrysomya rufifacies is one of the most forensically important flies because of its extremely predictable developmental time, minimal larval length difference, and low regional variation. C. rufifacies has a pupal developmental time ranging from 134 hours to 162 hours. The adult begins to form during the 237th hour to the 289th hour. This is useful for the forensic entomologist in determining the time of death for a corpse. C. rufifacies could have an impact in distorting post-mortem intervals by eliminating primary maggots on a corpse, due to its facultatively predacious nature during the second and third instar larval stages. The facultatively predacious instars feed on other dipteran larvae as alternative food sources, especially in conditions where limited food supply exists. Even undernourished larvae can successfully pupate and become healthy adults. Further altering of the postmortem interval can occur due to cannibalismCannibalism
Cannibalism is the act or practice of humans eating the flesh of other human beings. It is also called anthropophagy...
, which occurs when the second instar larvae consume the first instar larvae.
In the southeastern, central, and southwestern part of the United States the adult C. rufifacies is one of the first insects to arrive on a fresh corpse. The adults normally arrive within the first ten minutes after death. The larvae also have a shorter developmental time than other species, but because of their predaceous nature they can also alter entomological based postmortem interval estimation. In Texas and Florida, the species emerges from corpses that are in an advanced stage of decomposition.
Distribution
Chrysomya rufifacies can be found in a wide variety of human habitats. The fly is native to Australia and has been recently expanding greatly in distribution. Its wide distribution is due to natural dispersal and transportation through airplanes, boats, or automobiles. It occupies an altitudinal rage from sea level to 1,250 m, 1,400 m, or 2,100 m. The first appearance of the species in the continental United States occurred in the 1980s. The species is now established in Southern California, Arizona, Texas, Louisiana, and Florida. It can also be found in Japan, Central America, and India. It is expected to eventually occupy most of the United States in the near future. Due to rapid dispersion of the species, it has become the dominant blowfly on human cadavers in north and central Florida, while Chrysomya megacephala continues to be dominant in southern Florida.Future research
Chrysomya rufifacies is of primary forensic importance in the field of medicocriminal entomology and aids in establishing postmortem intervals. The species will become more significant ecologically, medically, and forensically as it displaces other native species and becomes a dominant blow fly. Future research is directed toward examining the potential effects of the widespread distribution of this species. Chrysomya rufifacies compete with the native CochliomyiaCochliomyia
Cochliomyia is a genus in the family Calliphoridae, known as blowflies, in the order Diptera. Cochliomyia are commonly referred to as the New World screwworm fly. There are four species in this genus: Cochliomyia macellaria, Cochliomyia hominivorax, Cochliomyia aldrichi, and Cochliomyia minima...
macellaria species and may cause the latter species to become extinct. The fly has been successful in competing with other species in many regions of the world. This newly achieved success will require close monitoring of the species in order to examine its ecological effects and determine any serious involvement in myiasis. Further research in the developmental and successional behavior of the species will allow for more accurate postmortem interval calculations in relation to the field of medicocriminal entomology.
External links
- hairy maggot blow fly on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
Featured Creatures Web site