Lucilia cuprina

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Lucilia cuprina
Australian sheep blowfly.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Calliphoridae
Genus: Lucilia
Species:
L. cuprina
Binomial name
Lucilia cuprina
(Wiedemann, 1830)
Synonyms
  • Phaenicia cuprina(Wiedemann, 1830)
  • Chloromelas gorgoneaLindner, 1949
  • Chloromelas heteroneura f. gorgonea Lindner, 1949
  • Odontomyia heteronevra Macquart, 1838
  • Stratiomyia heteroneura Walker, 1854
  • Stratiomys cuprina Wiedemann, 1830

Lucilia cuprina, formerly named Phaenicia cuprina, the Australian sheep blowfly is a blow fly in the family Calliphoridae. It causes the condition known as "sheep strike"'. The female fly locates a sheep with ideal conditions, such as an open wound or a build-up of faeces or urine in the wool, in which she lays her eggs. The emerging larvae cause large lesions on the sheep, which may prove to be fatal.

Contents

Anatomy

L. cuprina is a species of blow fly characterized by a metallic outer appearance and reddish eyes. They usually have a shiny green or greenish/blue abdomen with bronze/coppery reflections. Because of this, Lucilia species are known as the bronze bottle flies. [1] Their body shape is round to oval and their length varies from 4.5–10 mm. They have two pairs of wings, the first pair being membranous wings and the second pair being reduced wings known as halteres, which are used for flight stabilization. [2] Adults are easy to distinguish due to bristles on the meron, in addition to the arista, the prominent hair on the terminal antennal segment being plumose, or feathery. L. cuprina is most easily identified by its strong dorsal setae and black thoracic spiracle. It is almost indistinguishable from its conspecific L. sericata , and the difference between the two can be determined only by microscopic analysis of the occipital setae.

Habitats and diet

Although known as the Australian sheep blowfly, L. cuprina can be found in other parts of the world, including Africa and North America. These blow flies like warmer weather with soil temperatures above 15°C, air temperatures above 17 and below 40°C. They like low wind conditions with wind speeds below 30 km/h. Adapted perfectly to the Southern United States, this fly is well known because of its importance in forensic entomology. L. cuprina can fly up to 10 miles looking for food, and can be found on foods ranging from carrion to decaying fruit. Larvae are often found in shaded regions of carrion, while the adults prefer bright, open areas. [3]

Lifecycle

Adults of L. cuprina arrive early on carrion, appearing hours or even minutes after death. There, on the fresh body, they lay their eggs. The eggs then hatch into larvae that begin to feed and grow. After about five days, larvae enter the pupal stage. This is said to be an inactive stage, although many changes occur during this part of the flies’ lifecycle. The pupa does not feed, but rather uses the time inside the casing to change from a rice-like larva into an adult fly with wings and six legs. The whole process can take anywhere 11-21 days depending on environmental conditions, including temperature and food availability. In most cases, higher temperatures and a better plane of nutrition lead to a faster lifecycle. L. cuprina can have between four and eight generations per year depending mostly on temperature.

Effects on sheep

Blowfly strike, or flystrike, is a serious welfare problem in the animal industry. [4] This cutaneous myiasis or infestation not only causes severe discomfort or stress to the animal, but also causes death when left untreated. [5] Ewe lambs and female sheep are primarily affected and are struck predominately in the rear quadrant of the animal due to fecal staining. Due to the difficulty in controlling these flies, considerable losses in the sheep industry occur every year. Also, concern is increasing for insecticide use and the surgical procedures done to control L. cuprina, making this not only an animal welfare issue, but also an economical one. The maggots of L. cuprina rapidly grow while eating the living flesh of the sheep, and secrete ammonia, thus poisoning the sheep. Sheep show signs of skin irritation by rubbing and biting the affected areas during the first few days after the eggs have been laid. This causes an inflammatory response in the sheep, resulting in severe irritation and pyrexia. Once a flystrike has started, other flies are attracted to the site. Although treatment is available, the delayed response time due to symptoms allows wool breakage in the affected area and fleece to be tender overall. Many predispositions to the flystrike make a host more favorable, including an infection with dermatophilosis and footrot, both of which can be treated and prevented. In some animals, a weak resistance can develop, but this immune response is often associated with a decrease in productivity, which is an undesirable trait.

Prevention

Many options are available to prevent infestation. Many of the precursors drawing the flies initially are sanitary problems, which is where control measures are directed. Drenching, shearing, or crutching are basic procedures that can reduce flystrike. Crutching is the trimming of excess wool from the breech area, and the timing of both shearing and crutching is critical in reducing the amount of flystrike.

Surgical procedures are also performed in the sheep industry to help prevention, one of which is controversial due to its invasive nature. Tail docking to the correct length reduces the amount of staining in the breech area due to urine and fecal matter. Pizzle dropping severs the connective tissue between the penis and the body. Not only does it reduce the incidence of relentless pizzle rot in sheep, but it also decreases the amount of urine staining on the belly of the sheep. This procedure can greatly reduce the occurrence of flystrike on the belly area. Mulesing is an animal husbandry procedure that has recently faced opposition. Large scissors are used to cut off the backs of the sheep's thigh region. This procedure is usually carried out by untrained farmers without the use of any analgesia. It flattens out the wrinkles around the breech of the sheep, reducing the places where moisture collects, affecting the skin of the sheep and resulting in liquid protein exudate, which is attractive to L. cuprina. Mulesing also increases the amount of bare skin around the vulva during the healing process, reducing urine staining and amount of flystrike. This procedure does cause pain, but since it is considered the most effective method to prevent breech strike, it is seemingly justifiable. Mulesing is as effective as breeding sheep for less wrinkle (score 2), which are resistant to flystrike. Mulesing is a good prevention until breeding can remove the need for the operation in flystrike prevention

Insecticides have also been used often in prevention, but with improper application and heavy reliance throughout the years, insecticide resistance and residues within the wool have caused much concern. The primary reason for failures in using insecticides is attributed to poor application. Jetting, dipping, and backlining are the three most commonly used methods for insecticide application, and most of the chemicals used belong to these types of chemicals: synthetic pyrethroids, organophosphates, insect growth regulators, and spinosins. Insect growth regulators can provide the long-term protection against flies, and when applied correctly, provide protection during the susceptible times of the year. Resistance to this group of insecticide has been identified. Spinosins are good for short-term control of flies and leave no residues in wool. Many government agencies mandate that the wool be free of insecticidal residues, forcing withholding periods by farmers before shearing. During this time, the flock can become extremely sensitive to flystrike.

Baited traps are a good monitoring tool, and provide for some suppression of fly populations. Traps are a good addition to an integrated fly management program. A simple-to-use, nonchemical fly trap called Lucitrap targets L. cuprina. [6] This trapping system is now sold under the name Lucilure. [7] Many attempts have been made to find an alternative. [8] Vaccinations are currently being developed to help, but none has yet proved effective in the prevention of flystrike.

Demographics

Today, L. cuprina can be found throughout the world in various warm locations. Australia is one of the many places L. cuprina is found, and where it has been known to cause the most havoc. Its wide distribution is due to movement patterns and the traveling of humans and livestock within the last century. Although it can now be found worldwide, the species' origins are linked to afrotropical and oriental regions of the world.

L. c. cuprina is distributed in Neotropical, Oriental and southern Neartic regions, while L. c. dorsalis is found in Australasian, East, and sub-Saharan Afrotropical regions. [9]

Similar species

L. cuprina is one of many species of the family Calliphoridae. Though many of its species have similar characteristics, L. cuprina’s closest relative is its conspecific, L. sericata. These flies are very similar in appearance and morphological characteristics, which can sometimes cause errors when trying to differentiate between them. They each exhibit specific genetic variations, which can be distinguished by using random amplified polymorphic DNA and/or mitochondrial DNA sequences, and are known to cause myiasis (flystrike) in sheep. [9] They are some of the first blow flies to arrive at a corpse and each has smooth larvae. Unlike L. cuprina, L. sericata does not usually infest live sheep. L.cuprina is a worldwide sheep pest, though it is usually found in dry climates. L. sericata has a coastal distribution. [10]

Forensic importance

L. cuprina is often used as a helpful tool to aid medical and forensic professionals. Since it is one of the first flies to occupy a corpse upon its death, its lifecycle stage can helpdetermine time of death. Once it lands on a corpse, it lays its eggs, which hatch into larvae, followed by its pupal and finally the adult stages. Forensic professionals may then form a post mortem interval by the life stage found on the corpse. L. cuprina, although it is a worldwide pest, is very climate specific - dryer climates. A forensic investigator may conclude that a corpse has been relocated from its original location if it is found in a moist climate with L. cuprina on it.

The maggots of L. cuprina have been used by medical doctors for debridement therapy for patients who suffer from wounds that are healing slowly. [11] The maggots cleanse the wound by eating the dead and infectious skin and preventing gangrene and further infection.

Ongoing research

Current research involving L. cuprina and other Lucilia species range from identifying genetic variation between the different species to the ultrastructure of flies' eggs. Egg ultrastructure has recently become important in the field of forensic science. It is used to distinguish L. cuprina eggs from other Lucilia species, such as Lucilia illustris and Lucilia sericata . This defining feature becomes relevant when determining the post mortem interval because it varies with each species. [12] Other ongoing research includes bacteria and fungi associated with the insect. Numerous studies have been conducted to determine if the fly is a mechanical vector of bacteria. So far, many have been found only to be carriers and cannot transmit disease. [13] There have also been studies on the taxonomic grouping of Lucilia based on geography. The use of RAPD (Random amplified polymorphic DNA analysis) and mitochondrial DNA sequencing has been used to investigate genetic variation within the species. [9]

Related Research Articles

Maggot Larva of a fly

A maggot is the larva of a fly ; it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and crane flies. A 2012 study estimated the population of maggots in North America to be in excess of 3×1017.

Calliphoridae Family of insects in the Diptera order

The Calliphoridae are a family of insects in the order Diptera, with almost 1,900 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.

Myiasis Infestation of parasitic maggots

Myiasis is the parasitic infestation of the body of a live animal by fly larvae (maggots) which grow inside the host while feeding on its tissue. Although flies are most commonly attracted to open wounds and urine- or feces-soaked fur, some species can create an infestation even on unbroken skin and have been known to use moist soil and non-myiatic flies as vector agents for their parasitic larvae.

Mulesing is the removal of strips of wool-bearing skin from around the breech (buttocks) of a sheep to prevent the parasitic infection flystrike (myiasis). The wool around the buttocks can retain faeces and urine, which attracts flies. The scar tissue that grows over the wound does not grow wool, so is less likely to attract the flies that cause flystrike. Mulesing is a common practice in Australia for this purpose, particularly on highly wrinkled Merino sheep. Mulesing is considered by some to be a skilled surgical task. Mulesing can only affect flystrike on the area cut out and has no effect on flystrike on any other part of the animal's body.

Common green bottle fly Species of insect

The common green bottle fly is a blowfly found in most areas of the world and is the most well-known of the numerous green bottle fly species. Its body is 10–14 mm (0.39–0.55 in) in length – slightly larger than a house fly – and has brilliant, metallic, blue-green or golden coloration with black markings. It has short, sparse, black bristles (setae) and three cross-grooves on the thorax. The wings are clear with light brown veins, and the legs and antennae are black. The larvae of the fly may be used for maggot therapy, are commonly used in forensic entomology, and can be the cause of myiasis in livestock and pets. The common green bottle fly emerges in the spring for mating.

<i>Calliphora vomitoria</i> Species of fly

Calliphora vomitoria, known as the blue bottle fly, orange-bearded blue bottle, or bottlebee is a species of blow fly, a species in the family Calliphoridae. Calliphora vomitoria is the type species of the genus Calliphora. It is common throughout many continents including Europe, Americas, and Africa. They are fairly large flies, nearly twice the size of the housefly. They can be easily identified by their shiny, blue bodies.

<i>Cochliomyia</i> Genus of insects

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.

<i>Chrysomya rufifacies</i> Species of fly

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 post mortem 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 screwworms. This genus includes other species such as Chrysomya putoria and Chrysomya bezziana, which are agents of myiasis. C. rufifacies prefers very warm weather and has a relatively short lifecycle. 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.

Forensic entomological decomposition is how insects decompose and what that means for timing and information in criminal investigations. Medicolegal entomology is a branch of forensic entomology that applies the study of insects to criminal investigations, and is commonly used in death investigations for estimating the post-mortem interval (PMI). One method of obtaining this estimate uses the time and pattern of arthropod colonization. This method will provide an estimation of the period of insect activity, which may or may not correlate exactly with the time of death. While insect successional data may not provide as accurate an estimate during the early stages of decomposition as developmental data, it is applicable for later decompositional stages and can be accurate for periods up to a few years.

<i>Lucilia illustris</i> Species of insect

Lucilia illustris is a member of the fly family Calliphoridae, commonly known as a blow fly. Along with several other species, L. illustris is commonly referred to as a green bottle fly. L. illustris is typically 6–9 mm in length and has a metallic blue-green thorax. The larvae develop in three instars, each with unique developmental properties. The adult fly typically will feed on flowers, but the females need some sort of carrion protein in order to breed and lay eggs.

<i>Phormia regina</i> Species of fly

Phormia regina, the black blow fly, belongs to the blow fly family Calliphoridae and was first described by Johann Wilhelm Meigen.

Entomological evidence is legal evidence in the form of insects or related artifacts and is a field of study in forensic entomology. Such evidence is used particularly in medicolegal and medicocriminal applications due to the consistency of insects and arthropods in detecting decomposition quickly. Insect evidence is customarily used to determine post mortem interval (PMI), but can also be used as evidence of neglect or abuse. It can indicate how long a person was abused/neglected as well as provide important insights into the amount of bodily care given to the neglected or abused person.

<i>Lucilia silvarum</i> Species of fly

The common toad fly, Lucilia silvarum, is a member of the fly family Calliphoridae. This fly was first discovered by Johann Wilhelm Meigen in 1826 and is found most notably in European and Western Countries.

Lucilia thatuna belongs to the family Calliphoridae, the species most commonly referred to as the blowflies, and the genus Lucilia. Along with several other species of Lucilia, L. thatuna is commonly referred to as a green bottle fly. L. thatuna is very scarce and not much is known about this particular fly. It has been noted to reside in mountainous regions of the northwestern United States.

<i>Cynomya cadaverina</i> Species of fly

Cynomya cadaverina, also known as the shiny blue bottle fly, is a member of the family Calliphoridae, which includes blow flies as well as bottle flies. In recent years, this family has become a forensically important facet in many medicocriminal investigations in the growing field of forensic entomology. C. cadaverina is specifically important in determining a post-mortem interval, as well as other important factors.

<i>Lucilia mexicana</i> Species of insect

Lucilia mexicana is a species of blow fly of the family Calliphoridae, one of many species known as a green bottle fly. Its habitat range extends from southwestern North America to Brazil. L. mexicana is typically 6–9 mm in length with metallic blue-green coloring. This species is very similar in appearance to L. coeruleiviridis, the primary difference being that L. mexicana has two or more complete rows of post-ocular setae. L. mexicana has the potential to be forensically important in the stored-products and medicocriminal fields, but more research is needed for the fly to be used as evidence in criminal investigations.

<i>Calliphora livida</i> Species of fly

Calliphora livida is a member of the family Calliphoridae, the blow flies. This large family includes the genus Calliphora, the "blue bottle flies". This genus is important in the field of forensic entomology because of its value in post-mortem interval estimation.

<i>Lucilia coeruleiviridis</i> Species of fly

Lucilia coeruleiviridis, formerly Phaenecia coeruleiviridis, is commonly known as a green bottle fly, because of its metallic blue-green thorax and abdomen. L. coeruleiviridis was first discovered by French entomologist Pierre-Justin-Marie Macquart in 1855. It belongs to the family Calliphoridae and is one of many forensically important Diptera, as it is often found on decaying substances. L. coeruleiviridis is one of the most ubiquitous blow fly species in the southeastern United States, particularly in the spring and fall months.

<i>Calliphora stygia</i> Species of fly

Calliphora stygia, commonly known as the brown blowfly, or rango tumaro in Māori, is a species of blow-fly that is found in Australia and New Zealand. The brown blowfly has a grey thorax and yellow-brown abdomen.

Flystrike in sheep is a myiasis condition, in which domestic sheep are infected by one of several species of flies which are external parasites of sheep. Sheep are particularly susceptible to flystrike because their thick wool, if sufficiently contaminated with urine and faecal material, can provide effective breeding ground for maggots even in the relative absence of wounds.

References

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  2. Durden, C. (1999). Two-wing flies. In G. Zappler (Ed.), Texas insects (pp. 46-49). Austin, Texas: Texas Parks and Wildlife Press.
  3. Byrd, J. H., & Castner, J. L. (Eds.). (2001). Insects of forensic importance. In Forensic entomologist: The utility of arthropods in legal investigations (Phaenicia cuprina). Florida: CRC Press.
  4. A. C. Heath & D. M. Bishop (2006). "Flystrike in New Zealand: An overview based on a 16-year study, following the introduction and dispersal of the Australian sheep blowfly, Lucilia cuprina Wiedemann (Dipteran: Calliphoridae)". Veterinary Parasitology . 137 (3–4): 333–344. doi:10.1016/j.vetpar.2006.01.006. PMID   16464534.
  5. J. W. Plant (2006). "Sheep ectoparasite control and animal welfare". Small Ruminant Research. 62 (1–2): 109–112. doi:10.1016/j.smallrumres.2005.08.003.
  6. Urech, Rudolf; Green, Peter E; Rice, Martin J; Brown, Geoffrey W; Webb, Philip; Jordan, David; Wingett, Murray; Mayer, D avid G; Butler, Lock; Joshua, Edward; Evans, Ian; Toohey, Les; Dadour, Ian R (2009). "Suppression of populations of Australian sheep blowfly,Lucilia cuprina(Wiedemann) (Diptera: Calliphoridae), with a novel blowfly trap". Australian Journal of Entomology. 48 (2): 182–188. doi:10.1111/j.1440-6055.2009.00701.x. ISSN   1326-6756.
  7. "Bioglobal". Bioglobal.com.au. Retrieved 9 April 2022.
  8. Tellman, R.L. Eisemann, C.H. “Inhibition of growth of Lucilia cuprina using serum from sheep vaccinated with first-instar larval antigens.” International Journal for Parasitology 28 (1998):439–450
  9. 1 2 3 Jamie Stevens & Richard Wall (1997). "Genetic variation in populations of the blowflies Lucilia cuprina and Lucilia sericata (Diptera: Calliphoridae). Random amplified polymorphic DNA analysis and mitochondrial DNA sequences". Biochemical Systematics and Ecology . 25 (2): 81–87. doi:10.1016/S0305-1978(96)00038-5.
  10. "Archived copy". Archived from the original on 2009-02-18. Retrieved 2009-04-14.{{cite web}}: CS1 maint: archived copy as title (link)
  11. Mohd Marsi, S.; W.A. Nazni (2005). "Sterilisation of Lucilia cuprina Wiedemann Maggot Used in Therapy of Intractable Wounds" (PDF). Tropical Biomedicine. 22: 185–89. Retrieved 9 April 2022.
  12. Sukontason, K.L. Bunchu, N. Chaiwong, T. Kuntalue, B. Sukontason, K. “Fine structure of the eggshell of the blow fly, Lucilia cuprina.” 8pp. Journal of Insect Science 7:09 (2007), available online: insectscience.org/7.09
  13. Banjo, A.D. Lawal, O.A. and Akintola, O.I. “Bacteria and Fungi Associated with Lucilia cuprina (Sheep Blowfly) Larvae.” Research Journal of Agriculture and Biological Sciences 2.6 (2006): 358-364