Cynomya mortuorum
Encyclopedia
Cynomya mortuorum belongs to the order Diptera
, sometimes referred to as "true flies". In English, the only common name
occasionally used is "fly of the dead" ( in German
). It has a bluish-green appearance, similar to other Calliphoridae 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
. Current research is being done to determine C. mortuorums level of importance and usage within forensic entomology.
. Insects with this kind of life cycle have holometabolous
development, meaning that the larval stage looks completely different than the adult. Each of these stages has identifying characteristics that are unique to this species.
, which acts as a plastron. 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 studies.
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
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 segments 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.
Cynomya is generally identified by their lack of presutural intra-alar seta
. Also, this genus has a shining abdomen
, 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 parafacial
s, whereas C. cadaverina has black or reddish brown gena and parafacials. Also, C. mortuorum has only one postacrostichal seta, and C. cadaverina has two. Lastly, C. cadaverina is much more common throughout North America.
and Asia
. It has been found in the northern regions of both Europe and North America, and east to Turkestan
. Also, it can be found in a wide variety of carrion from rotting fish to Arctic vole
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. 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
.
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.
. It is often useful in estimating the post-mortem interval 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’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.
and Finland
area and is much less popular in the United States. 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
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.
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 used in this study was the large sub-unit (lsu) ribosomal RNA
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 Calliphoridae family, 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
.
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
, sometimes referred to as "true flies". In English, the only common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
occasionally used is "fly of the dead" ( in German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....
). It has a bluish-green appearance, similar to other Calliphoridae 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
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
. 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. This fly is a cold-adapted blowfly originally named by Carl Linnaeus in 1761. 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 most blow flies, or members of the Calliphoridae family, C. mortuorum has a life cycle that includes an egg stage, three larval instars, and a pupal form before becoming an adult, or imagoImago
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...
. Insects with this kind of life cycle have holometabolous
Holometabolism
Holometabolism, also called complete metamorphism, is a term applied to insect groups to describe the specific kind of insect development which includes four life stages - as an embryo or egg, a larva, a pupa and an imago or adult. Holometabolism is a monophyletic trait that all insects in the...
development, meaning that the larval stage looks completely different than the adult. 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 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 callophorid eggs. On the dorsal surface of the egg, there are two hatching pleats on either side of the chorionChorion
The chorion is one of the membranes that exist during pregnancy between the developing fetus and mother. It is formed by extraembryonic mesoderm and the two layers of trophoblast and surrounds the embryo and other membranes...
, which acts as a plastron. 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 studies.
Larvae
The larval stage is broken up into three instarInstar
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...
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
Vertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...
bands on segments 2 through 8 and complete posterior bands on segments 7 through 11. Also, the skeleton of this instar has a lateral
Human anatomical terms
Human anatomical terms make up a distinct nomenclature to describe areas of the body, to provide orientation when describing parts of human anatomy, and to distinguish different movements of the body. An understanding of these terms is necessary to study the human body in depth...
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 segments 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 of C. mortuorum are generally longer than pupae of Calliphora species, ranging from 8.49 to 9.75 mm.Identification
The genusGenus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Cynomya is generally identified by their lack of presutural intra-alar seta
Seta
Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
. Also, this genus has a shining abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
, 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
Cynomya cadaverina
Cynomya cadaverina, also known as the shiny blue bottle fly, is a member of the family Calliphoridae, which includes both 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...
. However, looking at specific characteristics can help separate these two species. First, C. mortuorum has bright yellow to orange gena, or cheeks, and parafacial
Parafacial
In Dipteran, the parafacial or parafacialia is the area between ptilinal fissure and the compound eye....
s, whereas C. cadaverina has black or reddish brown gena and parafacials. Also, C. mortuorum has only one postacrostichal seta, and C. cadaverina has two. Lastly, C. cadaverina is much more common throughout North America.
Ecology
C. mortuorum lives on woodland edges, meadows, and other places with flowers in EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. It has been found in the northern regions of both Europe and North America, and east to Turkestan
Turkestan
Turkestan, spelled also as Turkistan, literally means "Land of the Turks".The term Turkestan is of Persian origin and has never been in use to denote a single nation. It was first used by Persian geographers to describe the place of Turkish peoples...
. Also, it can be found in a wide variety of carrion from rotting fish to Arctic vole
Vole
A vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...
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. 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
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....
.
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.
Uses in forensic entomology
The use of C. mortuorum in the judicial system is most commonly applied to the medicocriminal branch of forensic entomologyForensic 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...
. It is often useful in estimating the post-mortem interval 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’s
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
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 NorwayNorway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
and Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
area and is much less popular in the United States. 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
Toxicology is a branch of biology, chemistry, and medicine concerned with the study of the adverse effects of chemicals on living organisms...
reports. Nozinan
Phenothiazine
Phenothiazine is an organic compound that occurs in various antipsychotic and antihistaminic drugs. It has the formula S2NH. This yellow tricyclic compound is soluble in acetic acid, benzene, and ether. The compound is related to the thiazine-class of heterocyclic compounds...
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.
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, DNADNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
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 used in this study was the large sub-unit (lsu) ribosomal RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
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 Calliphoridae family, 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
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...
.