Cynomya Mortuorum
   HOME

TheInfoList



OR:

''Cynomya mortuorum'' belongs to the order
Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...
, sometimes referred to as "true flies". In English, the only
common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...
occasionally used is "fly of the dead" (' in
German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...
). It has a bluish-green appearance, similar to other
Calliphoridae The Calliphoridae (commonly known as blowflies, blow flies, blow-flies, carrion flies, bluebottles, or greenbottles) are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing bait, ...
and is found in multiple geographic locations with a preference for colder regions. Belonging to the family Calliphoridae, it has been shown to have forensically relevant implications due to its appearance on
carrion Carrion (), also known as a carcass, is the decaying flesh of dead animals. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
. Current research is being done to determine ''C. mortuorums level of importance and usage within forensic entomology.


General characteristics and life cycle

''C. mortuorum'' is a deep blue-green shining metallic fly with a yellowish face and jowls, possessing a body length of 8–15 mm.Haupt, J./Haupt, H.: Fliegen und Mücken – Beobachtung, Lebensweise, Augsburg 1998 Honomichl, K./Bellmann, H.: Biologie und Ökologie der Insekten; CD-Rom, Gustav Fischer Verlag, Stuttgart 1994. West Palaearctic Distribution This fly is a cold-adapted blowfly originally named by
Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
in 1761.Erzincliolu, Y. Z. "Immature stages of British Calliphora and Cynomya, with a re-evaluation of the taxonomic characters of larval Calliphoridae (Diptera)." Journal of Natural History 19:1(1985): 69-96. It lays its eggs on carrion, which provides food for the larvae and facilitates the larvae's development. The development lasts approximately 38 days. As do most blow flies, or members of the family Calliphoridae, ''C. mortuorum'' has a life cycle that includes an egg stage, three larval instars, and a pupal form before becoming an adult, or
imago In biology, the imago (Latin for "image") is the last stage an insect attains during its metamorphosis, its process of growth and development; it is also called the ''imaginal'' stage ("imaginal" being "imago" in adjective form), the stage in wh ...
.Byrd, Jason H., and James L. Castner. Forensic Entomology: The Utility of Arthropods in Legal Investigations. Boca Raton, FL: CRC Press, 2001. Insects with this kind of life cycle have
holometabolous Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago (or adult). Holometabolism is a synapomorphic trait of all insects in the clade Holometabola. Immatur ...
development, meaning that the larval stage looks completely different from the adult.Brundage, Adrienne. Lecture. Orders and Diptera. College Station. 6 Feb 2009. Each of these stages has identifying characteristics that are unique to this species.


Egg

As an egg, it has been described as a whitish cylinder with a tapered
anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
end and blunt posterior end. The egg is generally 1.62 to 1.75 mm in length and 0.5–0.7 mm in width. These eggs are generally larger than other calliphorid eggs. On the dorsal surface of the egg, there are two hatching pleats on either side of the
chorion The chorion is the outermost fetal membrane around the embryo in mammals, birds and reptiles (amniotes). It is also present around the embryo of other animals, like insects and molluscs. Structure In humans and other therian mammals, the cho ...
, which acts as a
plastron The turtle shell is a shield for the ventral and dorsal parts of turtles (the Order (biology), order Testudines), completely enclosing all the turtle's vital organs and in some cases even the head. It is constructed of modified bony elements such ...
. Sometimes, the eggs can be difficult to separate from eggs of other species, so great care needs to be taken when using these eggs for
forensic Forensic science combines principles of law and science to investigate criminal activity. Through crime scene investigations and laboratory analysis, forensic scientists are able to link suspects to evidence. An example is determining the time and ...
studies.Erzincliolu, Y. Z.. "The value of chorionic structure and size in the diagnosis of blowfly eggs." Medical and Veterinary Entomology 3:3(1989): 281-285.


Larvae

The larval stage is broken up into three
instar An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...
s; and, each instar has 12 segments. The first instar is about 1.87 to 2.13 mm in length, and has complete anterior spinal bands on segments 2 through 8 and complete posterior bands on segments 7 through 11. Also, the skeleton of this instar has a
lateral Lateral is a geometric term of location which may also refer to: Biology and healthcare * Lateral (anatomy), a term of location meaning "towards the side" * Lateral cricoarytenoid muscle, an intrinsic muscle of the larynx * Lateral release ( ...
plate on which the narrowest portion is smaller than the length of the mouth hook; this is the same for the second instar. The second instar, however, is 2.74 to 3.75 mm in length, and has complete anterior spinal bands on segments 2 through 9 and complete posterior spinal bands on segments 8 through 11. Lastly, the third instar has been found to be 13.12 to 14.00 mm in length with complete anterior spinal bands on segments 2 through 8 and complete posterior spinal bands on segments 10 through 11. It can be distinguished from other third instar larvae in that the dorsal margin of its tooth is mostly straight, and then curves suddenly at the tip.


Pupae

The
pupae A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...
of ''C. mortuorum'' are generally longer than pupae of ''Calliphora'' species, ranging from 8.49 to 9.75 mm.


Identification

The
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Cynomya'' is generally identified by their lack of presutural intra-alar
seta In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae, ...
. Also, this genus has a shining
abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...
, and when they are viewed from the posterior, no microtomentum can be seen. Within this genus, there are two species that can be commonly confused: ''Cynomya mortuorum'' and '' Cynomya cadaverina''. However, looking at specific characteristics can help separate these two species. First, ''C. mortuorum'' has bright yellow to orange gena, or cheeks, and parafacials, whereas ''C. cadaverina'' has black or reddish brown gena and parafacial setae. Also, ''C. mortuorum'' has only one postacrostichal seta, and ''C. cadaverina'' has two. Lastly, ''C. cadaverina'' is much more common throughout North America.Whitworth, Terry. 2006
Keys to the Genera and Species of the Blow Flies (Diptera:Calliphoridae) of America North of Mexico
PROC. ENTOL. SOC. WASH. 30 June. 108(3), 699-708


Ecology

''C. mortuorum'' lives on woodland edges, meadows, and other places with flowers in
Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
and
Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...
. It has been found in the northern regions of both Europe and North America, and east to
Turkestan Turkestan,; ; ; ; also spelled Turkistan, is a historical region in Central Asia corresponding to the regions of Transoxiana and East Turkestan (Xinjiang). The region is located in the northwest of modern day China and to the northwest of its ...
. Also, it can be found in a wide variety of carrion from rotting fish to Arctic
vole Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of lo ...
carcasses. Within England, it has been found mostly in upland areas – above 500 m. In these upland areas, it is mostly found on small carcasses, such as mice and other small mammals; occasionally, it will be found on larger carcasses like sheep.Davies, L. "Species composition and larval habitats of blowfly (Calliphoridae) populations in upland areas in England and Wales." Medical and Veterinary Entomology 4:1(1990): 61-68. In the absence of carrion, excrement provides a food source. The adults feed on pollen, and are found from May to September. ''C. mortuorum'' has not been shown to cause
myiasis Myiasis ( ), also known as flystrike or fly strike, is the parasitic infestation of the body of a live animal by fly larvae (maggots) that grow inside the host while feeding on its Biological tissue, tissue. Although flies are most commonly attr ...
. As a cold weather fly, it is expected to show up in the fall months. However, one study found the presence of ''C. mortuorum'' on a mouse carcass in mid-August, and on a sheep carcass in mid-June.Davies, L. "Seasonal and spatial changes in blowfly production from small and large carcasses at Durham in lowland northeast England." Medical and Veterinary Entomology 13:3(1999): 245-251.


Uses in forensic entomology

The use of ''C. mortuorum'' in the judicial system is most commonly applied to the medicocriminal branch of
forensic entomology Forensic entomology is a branch of applied entomology that uses insects and other arthropods as a basis for legal evidence. Insects may be found on cadavers or elsewhere around crime scenes in the interest of forensic science. Forensic entom ...
. It is often useful in estimating the
post-mortem interval The post-mortem interval (PMI) is the time that has elapsed since an individual's death. When the time of death is not known, the interval may be estimated, and so an approximate time of death established. Postmortem interval estimations can ra ...
of a human cadaver. By studying the morphology and stage of development of the ''C. mortuorum'' obtained from a body, one can determine an estimate of a time of death for that body. Plenty of variables play into the use of insects in a criminal investigation, including temperature, certain chemicals, or location, but determining an
arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
's stage of development on a corpse proves to be an accurate technique in estimating a time of death. Calliphoridae eggs, like ''C. mortuorum'' eggs, usually hatch twenty-four to forty-eight hours after being laid. These specimens, once hatched, undergo three instars in their larval stage, which can take anywhere from four to twenty-one days. Another three to fourteen days account for the blow fly's pre-pupae stage, and, finally, the pupae stage can take an additional three to twenty days. Depending on certain variables, a forensic entomologist can pinpoint which stage of development a ''C. mortuorum'' is in, and how long it and the carcass it is feeding on have been there.


Forensic case studies

''C. mortuorum'' is used in numerous forensic cases as a source of post mortem interval information. The population tends to locate itself in the
Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...
and
Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...
area and is much less popular in the United States or the Iberian Peninsula. A current case located in Norway dealt with a deceased woman containing dead ''Cynomya mortuorum'' larvae in her oral cavity. It was a suicidal case that was proven by the
toxicology Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating ex ...
reports. Nozinan was found at extreme levels in the woman's blood, and to further prove the suicide, there were pills of this nature located directly next to the body. The larvae found in the mouth were strictly third instar larvae of ''C. mortuorum''. These were the only third instars found on the entire body. Forensic entomologists found that the eggs must have been laid in early October, since in Norway during December months, the temperature would have been too cold to sustain the larvae. Total developmental time consists of 25–31 days. Therefore, the woman had died in the same month, seeing that it takes less than a month's time to reach third instar development.Staerkeby, M. "Dead larvae of ''Cynomya mortuorum'' (L.) (Diptera, Calliphoridae) as indicators of the post-mortem interval — a case history from Norway." Forensic Science International 120:1(2001): 77-78.


Current research

''C. mortuorum'', as well as many other Calliphorid species are forensically important due to their predictable succession within a decomposing corpse, which can provide important information relating to time and place of death. In order to predict a valid time estimation, highly accurate species identification is essential. Using morphological methods to identify differences between such closely related species can often be very difficult, especially if the fly or larvae has been poorly preserved. With current technology,
DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
typing of these insects offers a quick and reliable alternative. In Europe and parts of the U.S., a study has been conducted collecting DNA sequence data over a range of commonly encountered forensically important Calliphoridae species. One species observed was the ''C. mortuorum''. This specimen was collected in Durham, UK. Flies used in this study were caught with liver-baited sticky traps. High quality DNA was extracted from these flies, and the
genetic marker A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can ...
used in this study was the large sub-unit (lsu) ribosomal
RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...
gene. (This lsu rRNA gene has also been used in studies of evolutionary analysis of other organisms.) The DNA analysis collected in this study provides insight to different evolutionary patterns apparent in the family Calliphoridae, which can possibly provide a measure of the degree of genetic variation likely to be encountered within taxonomic groups of different forensic usefulness. This study provides the first documented molecular based phylogenic analysis of the blowfly species. This research and more studies to come in the future will greatly assist the identification of larvae and adult insect species, which may play a great role in medicocriminal
forensic entomology Forensic entomology is a branch of applied entomology that uses insects and other arthropods as a basis for legal evidence. Insects may be found on cadavers or elsewhere around crime scenes in the interest of forensic science. Forensic entom ...
.Stevens, Jamie, and Richard Wall. "Genetic relationships between blowflies (Calliphoridae) of forensic importance." Forensic Science International 120:1-2(2001): 116-123.


Sources

{{Taxonbar, from=Q2445632 Calliphoridae Insects described in 1761 Diptera of Europe Taxa named by Carl Linnaeus