Muscina

{{short description|Genus of flies}} {{Automatic taxobox | image = Fly August 2008-3.jpg | image_caption = Adult ''Muscina stabulans'' | display_parents = 2 | taxon = Muscina | authority = Robineau-Desvoidy, 1830<ref name="Robineau-Desvoidy1830">{{cite journal |last1=Robineau-Desvoidy |first1=André Jean Baptiste |title=Essai sur les myodaires |journal=Mémoires presentés à l'Institut des Sciences, Lettres et Arts, par divers savants et lus dans ses assemblées: Sciences, Mathématiques et Physique |date=1830 |volume=2 |issue=2 |pages=1–813 |url=https://www.biodiversitylibrary.org/page/3472165#page/9/mode/1up |access-date=15 July 2018}}</ref> | type_species = ''M. stabulans'' | type_species_authority = Fallén, 1817<ref name="Coquillett01">{{cite journal | last = Coquillett | first = D.W. | year = 1901 | title = Types of anthomyid genera | journal = Journal of the New York Entomological Society | volume = 9 | issue = 3 | pages = 134–146 | author-link = Daniel William Coquillett | jstor = 25002949 }}</ref> }}

'''''Muscina''''' is a genus of flies that belongs to the family Muscidae, currently consisting of 27 species.<ref name=laura2>"ITIS Standard Report Page: Muscina." Integrated Taxonomic Information System. 20 Mar. 2009 <https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=150028></ref> They are worldwide in distribution and are frequently found in livestock facilities and outside restrooms. The most common species are ''M. stabulans'' (the most widely studied species), ''M. levida'', and ''M. prolapsa''. ''Muscina'' flies commonly breed in manure and defecate on food, which has been linked to the spread of some disease and illnesses.<ref name=numberseven>"False Stable Fly." North Carolina IPM. 20 Mar. 2009 <http://ipm.ncsu.edu/AG369/notes/false_stable_fly.html></ref><ref name=numbereight>"Fly Control In Confined Livestock And Poultry Production - Novartis Animal Health Inc." The Control Of Flies On Livestock And Poultry Farms - Novartis Animal Health Inc. 20 Mar. 2009</ref> The occurrence of ''Muscina'' larvae on dead bodies has led to their regular use in forensic investigations, as they may be used to estimate the time of death.<ref>{{cite book | last = White | first = Richard E. | title = A Field Guide to the Beetles of North America | publisher = Houghton Mifflin Harcourt | year = 1998 | location = New York, New York | pages = 208–214 | url = https://books.google.com/books?id=S9IK9OMjuNEC&q=Peterson+Field+Guides:+Beetles | isbn =978-0-395-91089-4 }}</ref> Research have shown the prevalence of certain species of ''Muscina'' flies as vectors of diseases such as poliomyelitis.<ref name=polio/>

==Characteristics== {{Multiple image | align = left | direction = vertical | width = 200 | image1 = | caption1 = ''Muscina levida'' wing | image2 = | caption2 = ''Muscina prolapsa'' wing }} ''Muscina'' species are characterized by a retractable proboscis, sponging or sucking mouthparts, and a pale tip on the scutellum.<ref name=numberone>{{cite journal |last1=Dodge |first1=Harold R. |title=Identifying common flies |journal=Public Health Reports |date=1953 |volume=68 |issue=3 |pages=345–350 |doi=10.2307/4588414 |jstor=4588414|pmid=13037962 |pmc=2023985 }}</ref><ref name=numberseven/> The species ''M. stabulans'' and ''M. levida'' are larger than the housefly, and have moderately curved fourth veins with the latter also having a black palpi. The species ''M. levida'' has legs that are entirely black. ''M. pascuorum'' flies have a red palpi, a strongly curved fourth vein that ends in or before the wing tip, and are generally larger than ''M. levida''.<ref name=numberone/>

==Life cycle== ''Muscina'' species undergo the same transformations throughout the life cycle as similar species and families in the order Diptera. Flies in the Dipteran order undergo what is known as holometabolous transformation, a type of metabolic transformation in which an insect starts out as an egg, undergoes larval stages, and then pupates before reaching full adulthood. The adult insect is referred to as an imago.<ref>{{cite web |url=http://www.amonline.net.au/insects/insects/metamorphosis.htm |title=Metamorphosis - A remarkable change |work=Insects |access-date=2006-04-22 |url-status=dead |archive-url=https://web.archive.org/web/20060422032155/http://www.amonline.net.au/insects/insects/metamorphosis.htm |archive-date=2006-04-22 }}</ref>

===Eggs and larvae=== Flies are completely wingless at the beginning of development. In normal fly production there can be as many as 250 eggs laid by a mature female.<ref>"Decomposition: Fly eggs." 11 Mar. 2009 <http://www.deathonline.net/decomposition/corpse_fauna/flies/eggs.htm></ref> The adult female keeps the eggs inside the abdomen until all of the eggs are produced and then lays the eggs through an ovipositor located on the hind end of the abdomen. thumb|''Muscina'' flies mating

These eggs are very small in size. Female adult flies usually choose decaying matter as sites to lay the eggs. These nutrient-rich areas are ideal for the growth and development of the hatching larvae. In contrast to adult flies, the larvae do not have a definite head. Instead, there are two grasping hooks that they use to cut and tear food.<ref name=ross5>{{cite web |url=http://www.britannica.com/EBchecked/topic/164747/dipteran |title=dipteran (insect) -- Britannica Online Encyclopedia |access-date=2009-04-01}}</ref> The larvae of ''Muscina'' have 11 segments. At the posterior end of the larvae are a set of spiracles. The spiracles of ''Muscina'' have spiracular slits that are not straight and exhibit some form of curvature.<ref name="Srinivasan et al 2008">{{cite journal |last1=Srinivasan |first1=R |last2=Sureshbabu |first2=L |last3=Chand |first3=P |last4=Shanmugam |first4=J |last5=Gopal |first5=R |last6=Shivekar |first6=S |last7=Senthil |first7=K |title=Intestinal myiasis caused by ''Muscina stabulans'' |journal=Indian Journal of Medical Microbiology |date=2008 |volume=26 |issue=1 |pages=83–5 |doi=10.1016/S0255-0857(21)02003-X |pmid=18227609 |doi-access=free |hdl=1807/53547 |hdl-access=free }}</ref> Larvae use the spiracles to breathe. The spiracles have a number of slits that can be used to determine what instar, or larval stage, the larvae are in; for example, one slit means first instar, two slits means second instar, and three slits means third instar.<ref name=ross5/> It has been shown that the environmental temperature has a strong influence on larval development: increasing temperature directly influences the amount of time that the larvae need to complete development.<ref name=ross4>{{cite journal |last1=Mascarini |first1=Luciene Maura |last2=Prado |first2=Ângelo Pires do |title=Thermal Constant of an Experimental Population of ''Muscina stabulans'' (Fallén 1817) (Diptera:Muscidae) in the Laboratory |journal=Memórias do Instituto Oswaldo Cruz |date=2002 |volume=97 |issue=2 |pages=281–283 |doi=10.1590/s0074-02762002000200026|pmid=12016459 |url=http://repositorio.unicamp.br/jspui/bitstream/REPOSIP/21607/1/S0074-02762002000200026.pdf }}</ref>

===Pupa=== After the larval phase, the Muscina larvae pass through a pupal stage. In this stage, there are many transformations that occur, such as the formation of legs, head, and wings. Simultaneously, a protective layer builds up and forms a cocoon, which aids in protection of the vital organs of the fly. ''M. levida'' is a species in this genus that does not form a cocoon. The duration of the pupal stage also varies depending on the temperature of the surrounding environment.<ref name=ross4/>

===Adults=== After sufficient time for pupal development has elapsed, the fly will be able to break out of its hard pupa shell, and the fly's wings begin to spread. Although completely formed in the pupa stage, the adult's wings do not reach its full size until outside the pupa covering. Through the use of blood vessels inside the wings, the fly is able to expand to full width and length and complete its life cycle.<ref name=ross5/>

==Medical importance== thumb|left|''Muscina'' fly with a drop of regurgitated fluid

Some insects have been shown to be potential carriers of pathogenic agents that can cause diseases. Mosquitoes and ticks as well as certain species of ''Muscina'' flies have been revealed to be possible vectors. ''M. stabulans'', along with almost two dozen other species of flies have been named the “disease-causing flies.”<ref name="urlwww.killgerm.com">{{cite web |url=http://www.killgerm.com/downloads/Hazards%20Pests%20Food%20Premises.pdf |title=www.killgerm.com |access-date=2009-04-01 |archive-url=https://web.archive.org/web/20080517055330/http://www.killgerm.com/downloads/Hazards%20Pests%20Food%20Premises.pdf |archive-date=2008-05-17 |url-status=dead }}</ref> Species of flies such as ''M. stabulans'' can spread bacterial and viral pathogens via transfer from its feet or mouthparts. Adult female flies tend to lay eggs in decaying material such as food or dead organisms and fresh fecal material. The fecal material houses a vast number of pathogenic bacteria, viruses, protozoan and other disease-causing agents. Most of the bacteria and viruses are not introduced from the fecal material to the fly when in the egg or larvae form; rather, the transfer occurs in the transition of a young fly to adulthood. Fecal particles attach to the fly's outer body as it emerges from the larvae. Transfer of bacteria occurs when the fly takes off and lands on an open wound or food material. Physical contact flakes the pathogen off the fly's body and causes contamination. The spread of a pathogen by means of a fly's outer body, such as its feet, to the host, is referred to as mechanical transmission. It is possible to determine the identify pathogen carried by identifying the species of fly. In these instances, food sanitation is an important preventive measure to ensure food safety.<ref name="pmid15653822">{{cite journal |vauthors=Graczyk TK, Knight R, Tamang L |title=Mechanical Transmission of Human Protozoan Parasites by Insects |journal=Clinical Microbiology Reviews |volume=18 |issue=1 |pages=128–32 |date=January 2005 |pmid=15653822 |pmc=544177 |doi=10.1128/CMR.18.1.128-132.2005 }}</ref> Moreover, a study of flies including ''M. stabulans'' and ''M. levida'' has shown that fly incidence peaked about 4–5 months before the occurrence of a poliomyelitis epidemic. This time period matches the time it takes for the infective agent to incubate in a human plus the extra time necessary for the fly to acquire and incubate the virus in its body.<ref name=polio>{{cite journal |last1=Power |first1=Maxwell E. |last2=Melnick |first2=Joseph L. |title=A Three-year Survey of the Fly Population in New Haven During Epidemic and Non-epidemic Years for Poliomyelitis |journal=The Yale Journal of Biology and Medicine |date=October 1945 |volume=18 |issue=1 |pages=55–69 |pmid=21434247 |pmc=2601852 }}</ref>

==Forensic importance== ''M. stabulans'' and ''M. levida'' belong to the ecological group of the filth fly.<ref name="numbersix">{{cite book |author1=Gary R. Mullen |url=https://books.google.com/books?id=u4RGXGkRq5YC&pg=PA280 |title=Medical and Veterinary Entomology |author2=Lance A. Durden |publisher=Elsevier |year=2002 |isbn=978-0-08-053607-1 |page=280}}</ref> ''Muscina'' flies are attracted to decaying organic matter, and are commonly found on corpses, urine, and feces. ''Muscina'' flies are useful in determining post-mortem intervals. The presence of ''Muscina'' larvae in diapers and on genitalia can indicate a timeline for the period of neglect in infant or elderly death cases. From the second instar phase onwards, ''M. stabulans'' are predacious upon other larvae, and will eat other forensically important arthropods.<ref name="url2000-07 Mark Benecke: Child neglect and forensic entomology - ForensicWiki">{{cite web |url=http://wiki.benecke.com/index.php?title=2000-07_Mark_Benecke:_Child_neglect_and_forensic_entomology |title=2000-07 Mark Benecke: Child neglect and forensic entomology - ForensicWiki |access-date=2009-04-01}}</ref> Presence of the false stable fly larvae on buried bodies enables investigators to estimate the time of death. The antennae of the false stable fly can detect buried bodies. In these cases, the fly lays its eggs on top of the soil, and the hatching larvae will then burrow and invade the corpse. The false stable fly will also lay its eggs in blood, even in the absence of a body.<ref name="isbn0-312-28774-7">{{cite book |author1=Erzinۅclioڷglu, Zakaria |author2=Zakaria Erzinclioglu |title=Maggots, murder, and men: memories and reflections of a forensic entomologist |publisher=Thomas Dunne Books |location=New York |year=2002 |isbn=0-312-28774-7 }}</ref> The presence of eggs in blood allows entomologists to estimate the time of injury, which helps investigators and crime scene investigators. ''Muscina stabulans'' are found on corpses in autumn and winter. In one experiment, ''M. stabulans'' larvae were found on a rabbit corpse two days after death. ''M. stabulans'' are present in the fresh stage, but are predominantly found in the adipocere-like stage, characterized by the hydrolysis of the carcass’ fatty tissue. In this phase, the carcass loses its shape and is a mass of hair, fat, skin, and cartilage. The skin eventually becomes rigid, protecting the larvae on the carcass and the insects living underneath the carcass.<ref name="de Souza et al 2008">{{cite journal |last1=de Souza |first1=Alex Sandro Barros |last2=Kirst |first2=Frederico Dutra |last3=Krüger |first3=Rodrigo Ferreira |title=Insects of forensic importance from Rio Grande do Sul state in southern Brazil |journal=Revista Brasileira de Entomologia |date=2008 |volume=52 |issue=4 |pages=641–646 |doi=10.1590/S0085-56262008000400016 |doi-access=free }}</ref>

==Myiasis== Myiasis is the feeding on live humans and vertebrates by dipterous fly larvae.

===Human=== ''Muscina'' flies are rarely seen on the skin of living mammals, but there has been one reported case where a ''Muscina'' species alone caused cutaneous myiasis in a human. A nine-year-old girl from Minnesota was reported with a lump on her wrist that was reddened and elevated, but showed no signs of any external openings or of containing any pus inside. A vaseline bandage was applied after some blood was extracted, and the lump was soaked in hot water several times. Twelve hours later, a worm was found in the cut after removing the bandage. Several other small lesions were noticeable around the proximity of the cut, but they receded at about this time. The girl recovered after applying a hot pack to the lesion. The larvae were confirmed by M. T. James of the State College of Washington and C. W. Sabrosky and W. W. Wirth of the United States National Museum to be a ''Muscina'' fly, most likely ''M. levida''.<ref>{{cite journal |last1=Barr |first1=A. Ralph |last2=Thompson |first2=John H. |title=A Case of Cutaneous Myiasis in a Child Caused by ''Muscina'' sp. |journal=The Journal of Parasitology |date=1955 |volume=41 |issue=5 |pages=552–553 |doi=10.2307/3273822 |jstor=3273822 |doi-access=free }}</ref>

''Muscina stabulans'' was reported in a case of intestinal myiasis. A twenty-year-old Indian man experienced abdominal discomfort, bloated abdomen, and intestinal hurrying after meals. Larvae of ''M. stabulans'' were found in the man's stool.<ref name="Srinivasan et al 2008" />

===Sheep=== In certain parts of the world where sheep production is important, ovine myiasis by certain dipteran species is a major concern. Areas where ruminant myiasis are problematic are Australia, Southern Africa, and the British Isles. ''M. prolapsa'' along with other dipteran flies have been identified in cases in southwestern Scotland.<ref>{{cite journal |last1=Morris |first1=Owen S. |last2=Titchener |first2=Richard N. |title=Blowfly species composition in sheep myiasis in Scotland |journal=Medical and Veterinary Entomology |date=July 1997 |volume=11 |issue=3 |pages=253–256 |doi=10.1111/j.1365-2915.1997.tb00403.x |pmid=9330256 |s2cid=30393977 }}</ref>

==Ongoing research== Current research have delved into the role ''Muscina'' flies play in forensics. ''Muscina stabulans'' was found to be an important fly in the determination of post-mortem intervals (PMI) in the Rio Grande do Sul state in southern Brazil. ''M. stabulans'' show up during the adipocere-like stage of decomposition whereby the carcass loses its natural shape due to hydrolysis of the fatty tissue. Moreover, ''M. stabulans'' appearance on bodies in large numbers during the autumn and winter months is useful in narrowing down time of death.<ref name="de Souza et al 2008"/>

==Species== {{multiple image | direction = horizontal | width = 200 | header = ''Muscina prolapsa'' | image1 = | caption1 = | image2 = Diptera-Muscidae-Muscina-prolapsa-201205120103.JPG | caption2 = Female }} {{multiple image | direction = horizontal | width1 = 200 | width2 = 200 | header = ''Muscina levida'' | image1 = | caption1 = Female | image2 = Diptera-Muscidae-Muscina-levida-201209210022.JPG | caption2 = Male }} *''Muscina angustifrons'' Loew, 1858<ref name=laura1>"|M. (Genus)."Welcome to ZipcodeZoo. 21 Mar. 2009<http://zipcodezoo.com/Key/Animalia/Muscina_Genus.asp#Overview {{webarchive|url=https://web.archive.org/web/20120604000533/http://zipcodezoo.com/Key/Animalia/Muscina_Genus.asp |date=2012-06-04 }}></ref> *''Muscina arcuata'' Shinonaga, 1989<ref name=laura1/> *''Muscina aurantiaca'' Hough, 1899<ref name=laura1/> *''Muscina brunnea''<ref name=laura1/> *''Muscina concolor''<ref name=laura1/> *''Muscina dorsilinea'' Wulp, 1896<ref name=laura2/> *''Muscina flukei'' Snyder, 1956 <ref name=laura2/> *''Muscina fulvacrura'' Snyder, 1956<ref name=laura2/> *''Muscina fungivora'' Robineau-Desvoidy, 1830<ref name=laura1/> *''Muscina grisea'' <ref name=laura1/> *''Muscina heterochaeta'' Villeneuve, 1915<ref name=laura1/> *''Muscina japonica'' Shinonaga, 1974 <ref name=laura1/> *''Muscina krivosheinae'' Lobanov, 1977<ref name=laura1/> *''Muscina latipennis''<ref name=laura1/> *''Muscina levida'' (Harris, 1780)<ref name="Harris1780">{{cite book |last1=Harris |first1=M. |title=An exposition of English insects |volume= Decads III, IV|date=1780 |publisher=Robson Co. |location=London |pages= 73-99, 100-138, pls. 21-30, 31-40 |url=https://www.biodiversitylibrary.org/item/226006#page/5/mode/1up |access-date=16 July 2021}}</ref> *''Muscina longicornis'' <ref name=laura1/> *''Muscina minor'' Portschinsky, 1881 <ref name=laura1/> *''Muscina pascuorum'' Meigen, 1826<ref name=laura2/> *''Muscina principalis'' Schiner, 1868 <ref name=laura1/> *''Muscina prolapsa'' (Harris, 1780)<ref name="Harris1780"/> *''Muscina stabulans'' Fallén, 1817<ref name=laura2/> *''Muscina sumatrensis'' Shinonaga & Kurahashi, 2002<ref name=laura1/> *''Muscina texana''<ref name=laura1/> *''Muscina tripunctata'' Wulp, 1896 <ref name=laura1/> *''Muscina varicolor''<ref name=laura1/>

==References== {{Reflist|30em}}

==Further reading== *[https://books.google.com/books?id=CvYuAAAAMAAJ&dq=Muscina+latipennis&pg=RA2-PA229 ''Muscina latipenis'' characteristics (pg. 229)] *[https://books.google.com/books?id=peJQEeZRuDUC&dq=Muscina+texana&pg=PP1 The Biological Bulletin] *[https://archive.org/stream/bookofflynatures00harduoft/bookofflynatures00harduoft_djvu.txt The Book of the Fly]

==External links== *[http://www.galerie-insecte.org/galerie/html/INSECTA__Diptera__Muscidae.html Common ''Muscina sp.'' pictures]

Category:Muscidae Category:Forensic entomology Category:Brachycera genera Category:Taxa named by Jean-Baptiste Robineau-Desvoidy