Draft:Sarcophaga argyrostoma

Sarcophaga argyrostoma
Flesh fly
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Diptera
Family:	Sarcophagidae
Genus:	Sarcophaga
Species:	S. argyrostoma
Binomial name
Sarcophaga argyrostoma

Sarcophaga Argyrostoma (Sar-co-phage-uh, ar-guy-ro-sto-ma) is a member of the flesh flies. Sarcophaga Argyrostoma is also known as the silver-faced flesh fly, of the Order Diptera, family Sarcophagidae.

As a member of the flesh flies, the species are known to consume flesh from living organisms or the decaying tissue post-mortem. The flies utilize the flesh tissue for feeding as well as suitable environments for proliferation/reproduction.

Description

With the classification from the order Diptera, which is the order encompassing the 'true-flies', distinguishing features would be the presence of only a single pair of wings, very large compound eyes, and mouthparts specialized for sucking, piercing and/or sponging.

With a classification of the family Sarcophagidae, the mouthparts would be primarily used for sponging and sucking, as opposed to mosquitos with piercing proboscis' of the same order Diptera.

Asides from the specific criteria of classification, flies as Arthropods will have general characteristics of 6 segmented limbs (3 pairs of legs) attached to the thorax, as well as the division of the head, thorax and abdomen.

Habitat

Colonization

Sarcophaga translates to 'meat eater', in which S. argyrostoma would typically inhabit necrotic tissue. Larvae of the species are detritovores (dead tissue). Although S. argyrostoma typically inhabit dead tissue, the larvae may also parasitize other invertebrates or decaying vegetable matter. Adult female flies also may deposit larvae, of the first instar, as opposed to eggs in suitable environments; the idea of this as opposed to decreased parental care of simply depositing eggs, is believed to give larvae a head start over other species of flies that deposit eggs in decaying tissue. Because of this reason, flesh flies are able to be utilized for forensic entomology due to the necrophagy of the species [[[Forensic entomology|Forensic Entomology]]]. The use of necrotic tissue seems to provide ideal environments for the Sarcophagid flies development.

Life cycle & development

Environmental effects

Varying environments can help to determine the efficacy of reproduction and development of flesh flies. The application of differing habitats (body tissue) can determine the rates of reproduction and/or the suitability of the environment on larval development. By studying these various flesh environments, the applications to forensic entomology can provide greater insight into criminal cases in which cadavers are involved.

Liver

In fresh liver at standard temperatures, S. argyrostoma are shown to have similar developmental processes to the common fly. Fresh liver may be seen as an ideal environment for development of Sarcophagid flies.

In decayed liver (91-days & 840-days) no difference in observation, regardless of temperature. It appears that flies do not have bias in terms of environment. Within liver tissue, fresh and decayed showed no apparent difference in larval density in which flies can utilize regardless of decomposition of tissue.

In addition to the environment effects on reproduction (in liver), temperature effects are added in addition to the fresh liver, S. argyrostoma exhibit an increase in larval density. By increasing temperature, temperature effects demonstrated greater efficacy for reproduction.

Fresh minced pork

In contrast to the liver environment, both the environment and temperature effects did not effect the larval density between fly species. Diptera flies may not have preference of tissue on the development of fly larvae.

Temperature effects and development

Temperature effects may have significant effects on the development of this species of flesh-eating flies. An in-depth breakdown, at 20^oC.

0 hours

Prepupae stage. Prepupae very soft and not yet sclerotized (darkened).

1st-9th hour

Pupae-form. Pupae with jelly-like appearance with cephalopharyngeal skeleton anterior (which will later become the head), and puparium of the anal area which will later develop to the abdomen.

22nd-27th hour

Cryptocephalic stage. Anterior and posterior-ends have now separated completely from the puparium. Larvae-like form without distinct head, thorax and abdomen structures.

29th-33rd hour

Leg and wing buds can be observed from the ventral aspect, respiratory horns can be observed from anterior end of dorsal view.

43rd-52nd hour

Respiratory horns separating posteriorly.

60th-65th hour

Phareocephalic stage. Head pushed anteriorly due to haemolymph pressure, respiratory horns pushed anterolaterally behind compound eyes and head, thorax and abdomen with more distinct borders formed. Wings and legs have now elongated towards end of abdomen.

73rd-85th hour

Pupal-adult ecdysis stage. Pupal skin beginning to be shed at the end of abdomen.

99th-102nd hour

Antennae begin to form and appear.

104th-110th hour

End/completed pupal-adult ecdysis. Pharate adult covered in pupal cuticle.

148th-172nd hour

Depression formed on dorsal side of abdomen.

194th-227th hour

Eye pigmentation change. Pigmentation from white to yellow with ocelli beginning to appear.

insert Ocelli image

248th-250th hour

Orange band formation in middle of eye.

252nd-259th hour

Orange pigmentation spread to entire eye contour.

261st-270th hour

Pigmentation spread to entire eye.

275th-295th hour

Eye pigmentation now orange-red in colouration.

309th-315th hour

Eyes continue to darken, and ocelli more distinct.

322nd-336th hour

Bristles around eyes, below antennae, and mouthparts orange in colouration and more distinct.

348th-357th hour

Further darkening of bristles. Bristles on thorax also not orange in colouration.

364th-370th hour

Bristle forming on abdomen. Antennae more distinct with pigmentation of costal vein on the wing increased.

381st-411th hour

Checkered pattern on abdomen distinct.

448th-455th hour

Beginning to shed pupal cuticle around pharate adult shed. Respiratory horns now removed from pupal cuticle.

458th-460th hour

Adult emergence.

S. argyrostoma adult emergence times can vary and become delayed under fluctuating temperatures. It can be observed that under constant temperature conditions, the early stages of intrapuparial tend to develop faster than environments that tend to fluctuate. In contrast, the pupal-adult apolysis can be observed to be longer within the constant temperature group. With the crucial development of specific body regions (bristles on the cephalo-thorax region) until adult emergence, constant temperatures are known to be superior at this phase.

Development rate, if not fluctuating, determines that as temperatures increase so does the development and the ability to undergo instars becomes available. It appears that as temperatures increase upward to the 30^oC mark, the development of the species decreases.

Impact (disease)

Myiasis

Myiasis is defined as the parasitic infection via fly larvae inside of a living organism. The infection can occur from wounds, or due to damage to skin tissue from the mouth parts of the fly. Penetration of tissue, whether dead or alive, serves the purpose of reproduction in Sarcophagid flies as they do not differentiate between living and necrotic tissue.

Human impact

Other areas can be affected such as, cutaneous surfaces (accidental/traumatic wound or furuncular creeping), or cavitary (nasal, aural/ear, ophthalmic/eye, nasopharyngeal, gastrointestinal, urinogenital, and rectal). Myiasis can cause for severe outcomes and loss of use due to necrosis of healthy tissue.

Wound Myiasis

Cases for wound myiasis are within the category of 'nosocomial myiasis agents' and are typically found in wound myiasis affecting hospital patients. The usual patients that are affected are those who are immobilized, often elderly or poorly cared for individuals. Due to the prevalence at the site (hospital), flies are attracted to fresh, untreated and infected wounds and utilize this to lay eggs. This action tends to exacerbate wounds and create necrotic (dead) tissue.

Gastrointestinal

Symptoms associated with weakness, gastrointestinal pain, vomiting, cramps, fever, fatigue and weight loss; another symptoms is watery stool/diarrhea.

Due to the environment being alive, the environment tends to not be suitable, however, due to the presence of fly eggs in human excrement, the term of 'pseudomyiasis'. The most common method of transmission of fly eggs are typically due to contaminated food ingestion.

Ear

With myiasis of the ear, symptoms include pruritus (itching), serosanguineous discharge (blood and serum). These symptoms also vary based on the severity and degree of myiasis. Although uncommon, severe effects, such as hearing loss, can also occur due to the damage from an adult fly or due to larval development and consumption of tissue.

Other animal impacts

In cases where live animals are affected by myiasis, whether domestic or wild, are typically due to open wounds in conjunction with a lack of grooming. A potential symptom that can occur is decubitus ulcers (pressure ulcer), which, in humans, are commonly known as bedsores. These ulcers are localized soft tissue injuries due to prolonged exerted pressure(s). In animals, this can be due to being wounded and to avoid pain responses, choose to limit mobility. Another factor that can exacerbate myiasis in animals can be due to unhealthy lifestyles such as being overweight and sedentary.

Medication/treatment for disease impact

Immunomodulatory and antioxidants

The application for Sarcophaga may be also used for medical applications such as utilizing the species as a mediator for antioxidants and anti-inflammation for disease control. The utilization is through the haemolymph found in the larvae of S. argyrostoma; a study is performed with snails and schistosomiasis in which the presence of cytokines in inflammation and other pathological processes (like parasitic infection). Further investigation of the mitochondrial DNA can be utilized for additional application for forensic entomology. The DNA barcoding can assist in a catalogue for the species which may assist in the criminology.

Forensic Entomology

The use of Sarcophaga in forensic entomology is namely due to the species of fly that tends to inhabit indoor environments with dead necrotic tissue. Through the use of understanding each developmental stages and instars of the fly help to determine the mortality of a corpse post-mortem. This concept is analogous to the theories of co-evolution in which, one evolution coincides with another. To explain the developmental phases being directly associated with post-mortem time of death, it allows for greater insight on potential criminology applications. Such applications include the use of Sarcophaga can and have been used for the determination of forensic studies, especially for the use of criminal cases; due to the species of fly that tend to feed on human cadavers.

DNA barcoding

The application of DNA barcoding can be applied to criminology. DNA barcoding can be utilized to solve difficult cases when there is a lack of evidence. It can be used to determine the species of fly and their potential environments, which may create a link between the victim of a case and the accused. Through this application, along with the timeline of development of a specific fly species, we can establish a link or association between a potential individual and the victim. This process has been utilized for both major crimes, such as homicide, as well as minor cases that involve cleanliness.