''Cynomya cadaverina'', also known as the shiny blue bottle fly, is a member of the family

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, ...

, 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 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 ...

. ''C. cadaverina'' is specifically important in determining a

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 ...

, as well as other important factors.

Taxonomy

''Cynomya cadaverina'' was first described in 1830 by the French entomologist

Jean-Baptiste Robineau-Desvoidy André Jean Baptiste Robineau-Desvoidy (1 January 1799 in Saint-Sauveur-en-Puisaye – 25 June 1857 in Paris) was a French physician and entomologist specialising in the study of Diptera (flies), and to some extent of the Coleoptera (beetles). Fl ...

. Its epithet ''cadaverina'' is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word, meaning ‘(that feed on) dead bodies.’Beard, J.R., & C., Cassell's Latin Dictionary, 1977, Cassell's, Pg. 501 This species is a member of 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 ...

and the diverse family Calliphoridae.

Description

''C. cadaverina'' is a fairly large species, ranging anywhere from 9-14 millimeters long. and has many characteristics that are common to its family, Calliphoridae.Hall, G., David, The Blowflies of North America, 1948, Thomas Say Foundation, Pgs. 327-331 These characteristics include their metallic color, having bristles on their meron as well as having plumose arista.Castner, L., James, Photographic Atlas of Entomology and Guide to Insect Identification, 2001, Feline Pr, Pg. 148 This species is known for having a shiny metallic blue

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 ...

for which it is named. It has a dark blue or black

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

and distinctive darker blue stripes present on the dorsum behind its head.Byrd, H., Jason, and James L. Castner, Forensic Entomology: The Utility of Arthropods in Legal Investigations, 2000, CRC, pg. 48 Along with these other characteristics, ''C. cadaverina'' also has white

calypters A calypter is either of two posterior lobes of the posterior margin of the forewing of flies between the extreme posterior wing base and the alula, which covers the halteres. The lower calypter is the proximal calypter (synonyms: squama (of som ...

, a bare stem vein, and a parafacial with a ground color ranging from black to reddish brown with a yellow covering.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), Pp.699-708

Distribution

''Cynomya cadaverina'' is known to range throughout the Neartic region with it being found mostly in southern Canada but also in the northern United States. Despite their normal location, they have also been found in states as far south as Florida and Texas. This species is known as a cool weather species and colonizes

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 ...

in the highest numbers in the spring and fall months. In most cases, they

overwinter Overwintering is the process by which some organisms pass through or wait out the winter season, or pass through that period of the year when "winter" conditions (cold or sub-zero temperatures, ice, snow, limited food supplies) make normal activ ...

as adults and may enter into houses during that time.Gill, J., Ginger, 2005,
"Decomposition and Arthropod Succession on Above Ground Pig Carrion in Rural Manitoba"
, Canadian Police Research Centre

Life cycle and development

Members of the order Diptera have a

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 ...

lifecycle, meaning they go through four life stages: egg,

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

pupa 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 ...

and

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 ...

, or adult. ''C. cadaverina'' typically has around 17 generations of offspring per year with 25 to 50 eggs per generation if the right conditions are present. Temperature can have an extreme impact on development. If the temperature gets above or below a certain temperature it can cause all development of the fly to stop. In general, the warmer it is, the faster the lifecycle will go; while if it is colder, the lifecycle may take longer than usual. This has to be taken into account when estimating the postmortem interval. Adults of ''C. cadaverina'' lay their eggs in open wounds or natural body openings on carrion, typically in small clusters or scattered singly.Southwestern Entomologist, 2003, Volume 1, Issue 1, Pg. 41 The eggs usually hatch out within 24 to 72 hours depending on the season. The eggs will then hatch into larvae that will go through three

instars An instar (, from the Latin ''wikt:instar#Latin, īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each ecdysis, moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the ...

(stages). Each one of these stages is separated by a

molt In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at ...

. During a molt, the larvae shed its outer layer in order to accommodate for new growth that comes with increased consumption of food needed for energy stores. The first instar typically lasts for approximately 20 hours, while the second instar lasts for 16 hours followed by the third instar for 72 hours. After the larvae have completed their development and stored as much energy as possible, they disperse to a safe area to complete their next stage, the pupal stage. This stage lasts for about 9 days before the fly finally emerges as an adult. The total lifecycle of ''C. cadaverina'' can take anywhere from 17–19 days depending on the temperature.

Forensic and medical importance

Post-mortem interval estimation

PMI estimation is used to figure out how much time has elapsed since a person died by using insects to help estimate this interval. It depends on the species of insect, as some are attracted to fresh corpses while others are only attracted to the

putrid Putrefaction is the fifth stage of death, following pallor mortis, livor mortis, algor mortis, and rigor mortis. This process references the breaking down of a body of an animal post-mortem. In broad terms, it can be viewed as the decomposi ...

and advanced stages of

decomposition Decomposition is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is ess ...

. This means the insects go through waves of succession. Using this information as well as the lifecycle of the insect in question can help to estimate the PMI. The judgment depends on what stage of development the insect is in, as well as the weather in recent months among other factors. Specifically with ''C. cadaverina'', they tend to be attracted to fairly advanced stages of decomposition, while rarely being found on fresh carrion. They also tend to be in the second wave of succession, usually showing up after ''Lucilia spp.'' and ''Calliphora spp.''Smith, G.V., Kenneth, A Manual of Forensic Entomology, 1987, Cornell Univ Pr, Pgs. 16 & 46

Myiasis and maggot therapy

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 ...

is the infestation of living or

necrotic Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who is ...

tissue in a living host by fly larvae. Some flies may just lay their eggs in a festering wound, while other may infest unwounded tissue. ''C. cadaverina'' has occasionally been found in cases of myiasis but is not a fly that is regularly found. Myiasis is fairly uncommon in the United States, but tends to be very common in third world countries and can create a major problem with livestock, causing severe economic losses. Myiasis is different from

maggot therapy Maggot debridement therapy (also known as MDT, larval therapy, or simply maggot therapy) is a type of biotherapy involving the introduction of live, disinfected maggots (fly larvae) into non-healing skin and soft-tissue wounds of a human or othe ...

in which physicians purposely use larvae of flies that feed on necrotic tissue in order to clean up a wound and aid healing. Maggot therapy can clean up a wound that has been festering for months very quickly.

Mitochondrial DNA analysis

In recent years, there have been numerous research projects on the topic of

mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...

analysis in fly larvae. In cases where larvae have fed on human tissue, these larvae are collected and then the gut is dissected out. The mitochondrial DNA from the gut is analyzed and can lead to the identification of the corpse the

maggot A maggot is the larva of a fly (order Diptera); it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, hoverflies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and cr ...

was feeding on as well as the species of the maggot itself.Wells, JD.
"Human and Insect Mitochondrial DNA Analysis From Maggots"
Journal of Forensic Sciences, Volume 46, Issue 3 This information could be critical if the body was too decomposed to lead to identification, or in other situations where identification would be near to impossible. Research concerning mitochondrial DNA analysis is currently being conducted on ''C. cadaverina'' in order to aid in investigations.

Disease transmission

''Cynomya cadaverina'' has been found to demonstrate communicative behavior via clustering and aggregation. It has been described by the

U.S. Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

as being a part of the "filthy fly" category, as it tends to breed in excrement and thrives in filthy habitats. This fly can also pose a health hazard due to the transmission of enteric

pathogens In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ...

that can lead to foodborne diseases in humans.

Future research

Further research is being conducted on ''Cynomya cadaverina'' to gain more information on its lifecycle as well as its behavior in order to better pinpoint

time of death ''Time of Death'' is a 2013 American documentary television series. It airs on the premium cable station Showtime. The series follows the lives and deaths of eight individuals and their families. It features Nicole "Little" Lencioni, an America ...

with postmortem interval estimation. This information will further aid forensic entomologists as well as investigators in solving medicocriminal investigations. Also, continued research on mitochondrial DNA analysis will be able to provide more identifications in cases where identification may have seemed impossible. Although'' Cynomya cadaverina'' is not as forensically or medically important as some of the other species of fly, it can still be a powerful tool in investigations as well as aid in maggot therapy.

References

External links

Bugguide.net
by L. Watson, M.J. Dallwitz
Entomology & Death: A Procedural Guide
by Elmer Paul Catts, Neal H. Haskell
Forensic Entomology: The Utility of Arthropods in Legal Investigations
by Jason H. Byrd, James L. Castner
The blowflies of North America
by David G. Hall
Kaufman field guide to insects of North America
by Eric R. Eaton, Kenn Kaufman {{Taxonbar, from=Q5199986 Calliphoridae Diptera of North America Insects described in 1830 Taxa named by Jean-Baptiste Robineau-Desvoidy