''Hydrotaea'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of insects in the housefly family,

Muscidae Muscidae are a family of flies found in the superfamily Muscoidea. Muscidae, some of which are commonly known as house flies or stable flies due to their synanthropy, are worldwide in distribution and contain almost 4,000 described species i ...

. They occur in most regions of the world but are more populous in warmer climates. They are often found on feces in summer months, and are therefore generally found in close proximity to

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animal ...

. Among the 130 known species in this genus, one of the most commonly recognized is the dump fly. Along with many others genera in the family, ''Hydrotaea'' is of

forensic Forensic science, also known as criminalistics, is the application of science to criminal and civil laws, mainly—on the criminal side—during criminal investigation, as governed by the legal standards of admissible evidence and criminal p ...

importance in both the economic and public health scene. Flies in general are considered by many authorities to be the most important insects involved in

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

and

veterinary medicine Veterinary medicine is the branch of medicine that deals with the prevention, management, diagnosis, and treatment of disease, disorder, and injury in animals. Along with this, it deals with animal rearing, husbandry, breeding, research on nutri ...

. Certain ''Hydrotaea'' species have been proven to carry and transmit certain diseases to warm blooded animals, including humans. Researchers continue to monitor these vectors of disease as they have been connected with the spread of

mastitis Mastitis is inflammation of the breast or udder, usually associated with breastfeeding. Symptoms typically include local pain and redness. There is often an associated fever and general soreness. Onset is typically fairly rapid and usually occurs ...

Species

Description

Larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e of this genus are often dimorphic obligate

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other s ...

s. The second and third

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

s are predators, and the first is also carnivorous in some species. Some species have

cannibalistic Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, bo ...

final instars. The smallest larvae are under 6 mm and the largest are up to 16 mm. The abdomen has ventral welts and large spiracles with

sinuate A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

slits. Adults commonly feed on the

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

of mammals. They are able to reopen wounds that are almost completely healed. Mouthpart

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts * Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...

in the genus ranges from sponging mouthparts to mouths with rasping teeth. Many species have enlarged prestomal teeth. The metathoracic spiracle is covered in long, thick

seta In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...

e. The average male ''Hydrotaea'' is 6.5-8.5 mm and the average female is 5.75-7.5 mm. They are very light brown to bluish black with large, red eyes and plumose antennae.

Habitat

Flies in this genus are found in the warmer parts of

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

, and Australia. They are most commonly found in

urban Urban means "related to a city". In that sense, the term may refer to: * Urban area, geographical area distinct from rural areas * Urban culture, the culture of towns and cities Urban may also refer to: General * Urban (name), a list of people ...

settings. They are attracted to fermentation and are often found in

vegetation Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characte ...

, feces, and

decomposing Decomposition or rot 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 e ...

carcasses, mainly those dead longer than ten days.

Life cycle

The

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring * Life-cycle hypothesis ...

of ''Hydrotaea rostrata'' has been studied in the field of

forensic entomology Forensic entomology is the scientific study of the colonization of a dead body by arthropods. This includes the study of insect types commonly associated with cadavers, their respective life cycles, their ecological presences in a given environme ...

. Mature flies seek out decay, preferably in material that has been dead for an extended amount of time. Masses of

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, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and crane flies. ...

s, which are often characteristic of other species of flies, are not typical of ''H. rostrata''. The larvae of this species progress through three stages, or

s, which are then followed by the formation of a

pupa A pupa ( la, pupa, "doll"; plural: ''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 thei ...

. The adult fly emerges from the pupa. The developmental process from egg to adult takes between 518.4 and 1555.6 hours, according to one study in Australia. Development is more rapid in warmer temperatures of . In cooler temperatures of , development may take up to 64.5 days. The larvae of another species, the black dump fly (''H. aenescens''), inhabit fecal material and consume other larvae, including those of ''

Musca domestica The housefly (''Musca domestica'') is a fly of the suborder Cyclorrhapha. It is believed to have evolved in the Cenozoic Era, possibly in the Middle East, and has spread all over the world as a commensal of humans. It is the most common f ...

'', the housefly. The black dump fly is commercially available for use in housefly control. It is also useful in forensics, as it may inhabit

corpses A cadaver or corpse is a dead human body that is used by medical students, physicians and other scientists to study anatomy, identify disease sites, determine causes of death, and provide tissue to repair a defect in a living human being. Stu ...

. Some larvae are able to seek shelter underground in cold conditions.

Associated pathogens

Research has incriminated ''Hydrotaea irritans'' as a vector of summer

, a

bovine Bovines (subfamily Bovinae) comprise a diverse group of 10 genera of medium to large-sized ungulates, including cattle, bison, African buffalo, water buffalos, and the four-horned and spiral-horned antelopes. The evolutionary relationship betwe ...

infection that can be caused by multiple suspected

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

. The research allowed flies inoculated with select bacteria from a sample representing summer mastitis to come in contact with the

udder An udder is an organ formed of two or four mammary glands on the females of dairy animals and ruminants such as cattle, goats, and sheep. An udder is equivalent to the breast in primates and elephantine pachyderms. The udder is a single mass han ...

s of

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

. The bacteria appeared in some of the cows and on the bodies of just over a third of the doctored flies. The evidence indicates that ''H. irritans'' transmits the bacterial species '' Staphylococcus aureus'', '' Streptococcus dysgalactiae'', '' Streptococcus uberis'', ''

Streptococcus agalactiae ''Streptococcus agalactiae'' (also known as group B streptococcus or GBS) is a gram-positive coccus (round bacterium) with a tendency to form chains (as reflected by the genus name ''Streptococcus''). It is a beta- hemolytic, catalase-negative, ...

'', '' Arcanobacterium pyogenes'', '' Peptostreptococcus indolicus'', and ''

Fusobacterium necrophorum ''Fusobacterium necrophorum'' is a species of bacteria responsible for Lemierre's syndrome and other medical problems. Biology ''F. necrophorum'' is a rod-shaped species of Gram-negative bacteria. It is an obligate anaerobe and is a common inh ...

''. ''H. irritans'' attacks many other warm-blooded animals, including humans. ''H. aenescens'' also carries bacteria, particularly ''Salmonella'' serovar Infantis.

Forensic importance

''Hydrotaea'' species have been helpful in forensic cases worldwide by indicating

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 ...

(PMI). These flies typically inhabit a carcass 4 to 5 months after the start of

decomposition Decomposition or rot 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 e ...

. Their presence indicates that the corpse was not burned and that the earlier

blow-fly The Calliphoridae (commonly known as blow flies, blow-flies, carrion flies, bluebottles, greenbottles, or cluster flies) are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing ba ...

phase has ended. ''Hydrotaea'' larvae may feed on each other and on other flies, such as blow-flies. ''Hydrotaea'' can be used to identify drugs and to determining whether a body was relocated. ''Hydrotaea spinigera'' can make up 70% of the muscid fly population on a corpse in forested habitat. ''Hydrotaea rostrata'' may arrive at a decomposing body on the second day of decay, and may stay up to 34 days or until the body is skeletonized.

References

{{Taxonbar, from=Q4194465 Muscidae genera Forensic entomology Diptera of North America Muscomorph flies of Europe Taxa named by Jean-Baptiste Robineau-Desvoidy Muscidae