Not to be confused with horsefly.
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Section: Schizophora
Family: Muscidae
Genus: Musca
Species: M. domestica
Binomial name
Musca domestica
Linnaeus, 1758
  • M. d. calleva Walker, 1849
  • M. d. domestica Linnaeus, 1758

The housefly (also house fly, house-fly or common housefly), Musca domestica, is a fly of the suborder Cyclorrhapha. It is the most common of all domestic flies, accounting for about 91% of all flies in human habitations, and indeed one of the most widely distributed insects, found all over the world; it is considered a pest that can carry serious diseases.


Physical description

A scan of a house fly taken at 40 magnifications under a scanning electron microscope.

The adults are 8–12 mm long. Their thorax is gray, with four longitudinal dark lines on the back. The whole body is covered with hair-like projections. The females are slightly larger than the males, and have a much larger space between their red compound eyes. The mass of pupae can range from about 8 to 20 mg under different conditions.[1]

Like other Diptera (meaning "two-winged"), houseflies have only one pair of wings; the hind pair is reduced to small halteres that aid in flight stability. Characteristically, the media vein (M1+2 or fourth long vein of the wing) shows a sharp upward bend. Species that appear similar to the housefly include:

  • The lesser house fly, Fannia canicularis, is somewhat smaller, more slender, and the media vein is straight.
  • The stable fly, Stomoxys calcitrans, has piercing mouthparts and the media vein is only slightly curved.

Life cycle

Anatomy of a housefly

Each female fly can lay approximately 500 eggs in several batches of about 75 to 150.[2] The eggs are white and are about 1.2 mm in length. Within a day, larvae (maggots) hatch from the eggs; they live and feed on (usually dead and decaying) organic material, such as garbage or feces. They are pale-whitish, 3–9 mm long, thinner at the mouth end, and have no legs. They live at least one week. At the end of their third instar, the maggots crawl to a dry cool place and transform into pupae, colored reddish or brown and about 8 mm long. The adult flies then emerge from the pupae. (This whole cycle is known as complete metamorphosis.) The adults live from two weeks to a month in the wild, or longer in benign laboratory conditions. After having emerged from the pupae, the flies cease to grow; small flies are not necessarily young flies, but are instead the result of getting insufficient food during the larval stage.[3]

The male mounts the female from behind

Some 36 hours after having emerged from the pupa, the female is receptive for mating. The male mounts her from behind to inject sperm. Copulation takes between a few seconds to a couple of minutes.[3] Normally the female mates only once, storing the sperm to use it repeatedly for laying several sets of eggs.

Housefly pupae killed by parasitic wasp larvae. Each pupa has one hole through which a single adult wasp emerged; feeding occurs during the wasp's larva stage.
Illustration of a housefly

The flies depend on warm temperatures; generally, the warmer the temperature the faster the flies will develop. In winter, most of them survive in the larval or the pupa stage in some protected warm location.[3]


Houseflies feed on feces, open sores, sputum, and moist decaying organic matter such as spoiled food, eggs, fruit and flesh.[4] Houseflies can take in only liquid foods. They spit out saliva on solid foods to predigest it. They also regurgitate partly digested matter and pass it again to the abdomen.

Sex determination

The housefly is an object of biological research, mainly because of one remarkable quality: the sex determination mechanism. Although a wide variety of sex determination mechanisms exist in nature (e.g. male and female heterogamy, haplodiploidy, environmental factors) the way sex is determined is usually fixed within one species. However, the housefly exhibits many different mechanisms for sex determination, such as male heterogamy (like most insects and mammals), female heterogamy (like birds) and maternal control over offspring sex. This makes the housefly one of the most suitable species to study the evolution of sex determination.[5]


Even though the order of flies (Diptera) is much older, true houseflies are believed to have evolved in the beginning of the Cenozoic era, some 65 million years ago.[6] They are thought to have originated in the southern Palearctic region, particularly the Middle East. Because of their close, commensal relationship with man, they probably owe their worldwide dispersal to co-migration with humans.[3]

Flies and humans

In colder climates, houseflies survive only with humans. They have a tendency to aggregate and are difficult to dispel. They are capable of carrying over 100 pathogens, such as typhoid, cholera, salmonella, bacillary dysentery, tuberculosis, anthrax, ophthalmia, and parasitic worms. Some strains have become immune to most common insecticides.

House flies feed on liquid or semiliquid substances beside solid material which has been softened by saliva or vomit. Because of their high intake of food, they deposit feces constantly, one of the factors that makes the insect a dangerous carrier of pathogens. Although they are domestic flies, usually confined to the human habitations, they can fly for several miles from the breeding place. They are active only in daytime, and rest at night, e.g., at the corners of rooms, ceiling hangings, cellars, and barns, where they can survive the coldest winters by hibernation, and when spring arrives, adult flies are seen only a few days after the first thaw.

Housefly as a transmitter of disease

Mechanical transmission of organisms on its hairs, mouthparts, vomitus and feces:


  1. ^ Larraín, Patricia & Salas, Claudio (2008). "House fly (Musca domestica L.) (Diptera: Muscidae) development in different types of manure [Desarrollo de la Mosca Doméstica (Musca domestica L.) (Díptera: Muscidae) en Distintos Tipos de Estiércol]". Chilean Journal of Agricultural Research 68 (2): 192–197. doi:10.4067/S0718-58392008000200009. ISSN 0718-5839. 
  2. ^ Stuart M. Bennett (2003). "Housefly". 
  3. ^ a b c d Anthony DeBartolo (June 5, 1986). "Buzz off! The housefly has made a pest of himself for 25 million years". Chicago Tribune. 
  4. ^ Adapted from Dewey M. Caron (1999). "House flies". University of Rhode Island. 
  5. ^ Dübendorfer A, Hediger M, Burghardt G, Bopp D. (2002). "Musca domestica, a window on the evolution of sex-determining mechanisms in insects". International Journal of Developmental Biology 46 (1): 75–79. PMID 11902690. 
  6. ^ Brian M. Wiegmann, David K. Yeates, Jeffrey L. Thorne, Hirohisa Kishino, a fly's head, showing compound eyes and hair
  7. ^ A. L. Szalanski, C. B. Owens, T. Mckay & C. D. Steelman (2004). "Detection of Campylobacter and Escherichia coli O157:H7 from filth flies by polymerase chain reaction". Medical and Veterinary Entomology 18 (3): 241–246. doi:10.1111/j.0269-283X.2004.00502.x. PMID 15347391. 
  8. ^ Sheri M. Brazil, C. Dayton Steelman & Allen L. Szalanski (2007). "Detection of pathogen DNA from filth flies (Diptera: Muscidae) using filter paper spot cards". Journal of Agricultural and Urban Entomology 24 (1): 13–18. doi:10.3954/1523-5475-24.1.13. 

External links

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Look at other dictionaries:

  • housefly — house fly n. 1. common fly ({Musca domestica}) that frequents human habitations and spreads many diseases. Syn: {Musca domestica}. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • housefly — early 15c., from HOUSE (Cf. house) (n.) + FLY (Cf. fly) (n.) …   Etymology dictionary

  • housefly — ► NOUN ▪ a common small fly occurring in and around human habitation …   English terms dictionary

  • housefly — [hous′flī΄] n. pl. houseflies any of a genus (Musca) of disease carrying muscid flies found in and around houses, and feeding on garbage, manure, and food; esp., a common worldwide species ( M. domestica): see INSECT …   English World dictionary

  • housefly — /hows fluy /, n., pl. houseflies. a medium sized, gray striped fly, Musca domestica, common around human habitations in nearly all parts of the world. Also, house fly. [1400 50; late ME; see HOUSE, FLY2] * * * Common dipteran (Musca domestica),… …   Universalium

  • housefly — UK [ˈhaʊsˌflaɪ] / US noun [countable] Word forms housefly : singular housefly plural houseflies a very common flying insect that often lives in houses and is attracted by food …   English dictionary

  • housefly — noun Date: 15th century a cosmopolitan dipteran fly (Musca domestica) that is often about human habitations and may act as a mechanical vector of diseases (as typhoid fever); also any of various flies of similar appearance or habitat …   New Collegiate Dictionary

  • housefly — noun The common fly, of the species Musca domestica that occurs in most homes; it can spread some diseases …   Wiktionary

  • housefly — See Musca, Fannia. * * * house·fly .flī n, pl flies a cosmopolitan dipteran fly of the genus Musca (M. domestica) that is often found about human habitations and may act as a mechanical vector of diseases (as typhoid fever) also any of various… …   Medical dictionary

  • housefly — house|fly [ˈhausflaı] n plural houseflies a common type of fly that lives in people s houses …   Dictionary of contemporary English