Derivation of scientific name: Swedish botanist and scientist Carl Linnaeus originally named the housefly Musca domestica in his 1758 Systema naturae based on common European specimens, and it is still categorised under that name today (Pont 1981). The scientific name Musca domestica is derived from Latin, Musca meaning ‘fly’, while domestica refers to its close association with human habitation. The name reflects the housefly’s common presence in and around human dwellings.
Musca domestica, commonly known as the housefly, is a ubiquitous and cosmopolitan insect that has adapted to coexist with human activities worldwide (Sarwar 2015). These small, greyish-brown flies, which are members of the Muscidae family, are distinguished by their bristle-covered bodies, spongy mouthparts and compound eyes (Iqbal et al. 2014). Since houseflies are known to spread numerous infections by contaminating food and surfaces with their saliva and excrement, they serve as both a nuisance and a possible health risk (Khamesipour et al. 2018). Their abundant presence in both urban and rural habitats can be attributed to their quick and adaptive reproductive cycle, in which females deposit hundreds of eggs in decomposing organic waste. Houseflies are a recurring problem for sanitation efforts because of their short lifespan, surprising resistance against popular pesticides and their resilience (WHO 1986).
Description/How to recognize a common housefly.
The adult housefly is identified by their short aristate antennae, a generally grey thorax with four darker dorsal longitudinal stripes, and a grey or yellowish abdomen with an irregular light yellowish patch at the anterior lateral edges. Males have eight segments in the abdomen, while females have nine. The first five segments are visible on the outside in females. When the female deposits her eggs, the final four segments, which are ordinarily retracted, expand to form the ovipositor. Females may bury the eggs several millimetres below the surface of a substrate with the ovipositor. Compared to the males, females are slightly bigger in terms of relative body size ratio. Houseflies only have one set of flying wings, just as all other flies (the order name, ‘Diptera’, means ‘two-winged’) with another hind wing set reduced to halteres, which are used for balance while in flight, and are all that remain of the second pair. Their membranous wings are translucent and fold back straight at rest. The average body length (head to abdomen) of a housefly is 6.35 mm, with a range of 4 to 8 mm (Borror & DeLong 1971; Robinson 2005; Geden et al. 2021).
Adult houseflies have mouthparts that resemble sponges. The mouthparts consist of two lobes, termed the labella, that are linked to the labium, or lower lip, and are grooved with fleshy tissue. These lobes have a lot of transverse grooves on their bottom surface, which act as channels for liquid food. Only liquid food is ingested by houseflies. The rostrum, a membranous protrusion of the lower skull, is where the mouthparts is attached to the head. The mouth hooks on the larvae are used to filter-feed on large amounts of bacteria (Borror & DeLong 1971; Robinson 2005; Geden et al. 2021). When fully developed, larvae are 12 to 13 mm in length after three instar stages with a yellowish-white colour. They have paired hooks on the head, glossy smooth bodies without prolegs and are called maggots. They have two spiracles, a blunt rear end, and a pointed anterior end (head region). Between abdomen segments 1 and 7 there is a little patch of tiny spines located ventrally; however, the thoracic segments lack this patch. The non-motile pupa stage might take up to six days before adults emerge at optimal growth conditions (Borror & DeLong 1971; Robinson 2005; Geden et al. 2021).
Getting around
Keiding & WHO (1986) described house flies as skilled fliers that can move forward at a speed of 6 to 9 km/h; however, they don’t typically take long flights as they are not migratory by nature. They travel a lot to explore their surroundings, but they usually stay within a 100–500 m radius of the nesting site if they can locate adequate and suitable food, shelter and breeding grounds. Though some house flies from a focus may spread further in good weather, particularly if there is overpopulation at the breeding site, they can be found at areas of attraction up to 5 km away in a town or village, or in nearby farms or villages.
Communicating
Houseflies have olfactory, tactile, visual and chemical senses mediated by pheromones. To locate food, olfactory senses are heavily utilised. Their olfactory system’s chemical perceptions trigger an electrical reaction in the antennae. Researchers can tell if a housefly under investigation is drawn to or repelled from an odour by observing the electrical spikes in the activation of sensory cells on its antennae. Because of this characteristic, humans have created commercial repellents with offensive scents (Kelling et al. 2002). Houseflies use tarsi (taste hairs), many of which are found on their feet, to detect food. They have setae (hairs) all over their bodies that are used to detect airflow. They can also distinguish between lights and motion due to their compound eyes and ocelli, which provide them with an excellent sense of sight. Houseflies utilise pheromones as part of a species recognition system to communicate as well as for copulation (Kelling et al. 2002).
Distribution
The housefly is probably the insect that is most widely distributed in the world, and localised population sizes can grow to unbearable levels. Their cosmopolitan spread has been attributed their close association with people and animals as well as easy substrate contamination, which allows them to travel around the globe. The species is found in large quantities from the tropics to the Arctic. All highly populated regions of the Americas, Europe, Asia, Africa and Australasia are home to houseflies (Hewitt 2011). Major South African cities like Johannesburg, Cape Town, Durban and Pretoria all have large populations of houseflies due to the abundance of waste and suitable breeding grounds in these densely populated urban centres. To date, houseflies continue to be found on all inhabited continents, in all climates from tropical to temperate, and in a range of situations from rural to urban.
Habitat
A large portion of houseflies spend the day outside or in covered spaces close to the open air, such as marketplaces, bazaars, sheds and verandas, as well as stores, eateries and rooms with open facades. They thrive in warm climates and seasons. The majority of houseflies are found on low-lying vegetation, floors, tables and other horizontal surfaces when they are not feeding or in nesting locations. In warm regions, appealing interior spaces such as kitchens, privies and livestock sheds may also have a high daytime housefly incidence. Houseflies are most active and live longest in temperatures between 10°C and 26.6°C (Marshall 2006). Furthermore, when temperatures in the shade increase beyond 30°C during the day, flies may relocate to cooler areas such as inside buildings (Keiding & WHO 1986).
Food
Houseflies consume any moist or early stages of decomposing organic material, but because pet faeces have such a strong smell, they are particularly drawn to it. Houseflies, both male and female, consume all forms of human food as well as perspiration, excrement, trash and animal manure. To make solid food easier to dissolve before consumption, house flies suck up liquid food and moisten solid food with saliva. Its food must include water since it cannot survive for longer than 48 hours without it. Houseflies can also feed on milk, sugar, beef broth and a variety of other items found in regions where people live. Houseflies need to eat two or three times a day (Keiding & WHO 1986).
SEX and LIFE CYCLES
A female housefly can produce four to six hatches, with 75 to 150 eggs in each hatch. To prevent desiccation, eggs are placed in cracks. Houseflies primarily breed in filthy food and trash (Cosse & Baker 1996). An adult housefly’s life cycle is between 15 and 30 days. Males are ready to mate the day they emerge, but females need to be three days old for mating to take place (Sacca 1964). Following a few days of copulation, oviposition occurs. Eggs are pear-shaped, white and measure between one and two millimetres in length. Within a day of oviposition, eggs hatch into larvae (maggots), and within a week, the larvae go through three stages of development (called instars). Maggots are saprophagous in nature, without legs, 3–9 mm long, whitish in colour, and feed on dead or decaying organic matter such as waste or excrement. They have a 14 to 36-hour lifespan. Maggots, or larvae, crawl to a colder, drier location after completing their third instar, where they transform into pupae. The pupa is roughly 8 mm long and reddish-brown in hue. In five days, the pupa finally transforms into an adult housefly. The housefly takes two to three weeks to complete its life cycle in warm climates. Because of its high rate of development and prolific egg production, it generates a big population quickly. In a temperate environment, it can produce 10–12 generations a year. In contrast, they can only breed during the warmer months in colder climates, where they could generate four to six generations (Keiding 1986; Kettle 1990).
Family life:
THE BIG PICTURE
Friends and Foes
Houseflies have natural enemies such as nematodes, parasitic wasps (some pteromalid species), fire ants, predatory beetles (histerial and staphylinid species), mites, flies (Hydrotaea aenescens) and birds that can be used as biological control agents to help reduce the population of houseflies (Iqbal et al. 2014). Some bacterial species have a mutualistic relationship with houseflies such as Salmonella spp., Yersinia enterocolitica, Edwardsiella tarda, Shigella sonnei, Escherichia coli, Klebsiella spp., Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis (Rahuma et al. 2005), to mention a few.
Smart Strategies
The house fly uses its proboscis and chemotactic sensors on its feet to detect prospective food when it comes into touch with it. These receptors are particularly sensitive to sugar solutions. The fly stops, stretches its proboscis, and may begin feeding if the taste is satisfactory. Food that is liquid is sucked up, while solid food that is soluble (like sugar) needs to be wetted and dissolved by saliva and crop fluids first (Keiding 1986).
Poorer world without me
The ecological role of house flies is mainly to serve as decomposers of organic waste. Additionally, they are an important food source for various animal taxa, including birds, mammals and other insects. In scientific research, they are used as base assay model organisms and have contributed to the understanding of genetics, behaviour and disease transmission. Houseflies can be used as experimental organisms to assist in understanding disease condition dynamics and treatment (as in anti-tumour and anti-bacteria research). However, their absence could impact the ecosystem dynamics as they play a role in nutrient recycling and serve as a food source for other organisms.
People & I
The housefly plays its role as a vector of diseases in humans, poultry and livestock from where it scatters to human habitats and activities (Moriya et al. 1999). It is a causative agent for the spread of various diseases like typhoid, dysentery, diphtheria, leprosy, tuberculosis and intestinal parasites in humans, while diseases related to poultry and livestock includes fowl cholera and anthrax. Their frequent movements between animal and human sources of food and filth make them good transmitters of zoonotic diseases through the spread of pathogens (Iqbal et al. 2014).
Fly maggot dead skin tissue therapy
Maggot therapy (larva therapy, biosurgery or Maggot Debridement Therapy (MDT)) is the medical use of live maggots for cleaning human chronic and non-healing wounds or certain wounds that are not amenable to other forms of therapy (Sherman et al. 2000). The most commonly used species of flies are blowflies. Sherman (2002) describes how blowflies typically ‘blow’ (deposit) their eggs on carrion, faeces or necrotic flesh. Depending on the species and the surroundings, the larvae feed on necrotic tissue for three to seven days after hatching. Digestive enzymes are released into the surrounding environment by maggots. They develop and moult twice while they consume the liquefying tissue. The maggots pupate after leaving their food supply and bury themselves in a suitable spot once they are satiated. Flies mature and emerge after one to three weeks. Up to 2 000 or 3 000 eggs can be laid by a single gravid female, who frequently deposits them throughout a few weeks at various locations (Sherman 2002).
Conservation status and what the future holds
Houseflies are not listed on any conservation status list as they are extremely abundant and widely distributed across the globe. They are not considered endangered or under threat in any way.
Relatives
Houseflies belong to the Muscidae family within the order Diptera, which includes various other fly species. Some of its relatives within the Muscidae family include the stable fly (Stomoxys calcitrans), which is similar in appearance to the housefly. Stable flies are known for their painful bites and are often associated with livestock (Malik et al. 2007). The little housefly genus, Fannia, includes small flies that are commonly found in and around houses (Malik et al. 2007). They share similarities in habitat and behaviour with houseflies. The horn fly (Haematobia irritans), which is a blood-feeding fly and the face flies (Muscina spp.) are pests of livestock known for congregating around the faces of these animals (Malik et al. 2007).
Scientific Name and Classification:
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Muscidae
Genus: Musca
Species: M. domestica Linnaeus, 1758
References
- Borror, D.J. & DeLong, D.M. 1971. An introduction to the study of insects (No. Ed. 3). New York, USA, Holt, Rinehart & Winston.
- Cosse, A.A. & Baker, T.C. 1996. Houseflies and pig manure volatiles: wind tunnel behavioral studies and electrophysiological evaluations. Journal of Agricultural Entomology, 13: 301 –317.
- Geden, C.J., Nayduch, D., Scott, J.G., Burgess IV, E.R., Gerry, A.C., Kaufman, P.E., Thomson, J., Pickens, V. & Machtinger, E.T., 2021. Housefly (Diptera: Muscidae): biology, pest status, current management prospects and research needs. Journal of Integrated Pest Management 12,1: 39.
- Hewitt, C.G.. 2011. The housefly. United Kingdom, Cambridge University Press.
- iNaturalist. 2024. https://www.inaturalist.org/taxa/120156-Musca-domestica. Accessed 17 January 2024
- Iqbal, W., Malik, M.F., Sarwar, M.K., Azam, I., Iram, N. & Rashda, A. 2014. Role of housefly (Musca domestica, Diptera; Muscidae) as a disease vector; a review. Journal of Entomology and Zoology Studies 2,2:159–163.
- Keiding, J. & World Health Organization. 1986. The housefly: biology and control (No. WHO/VBC/86.937. Unpublished). World Health Organization.
- Kelling, F., Lalenti, F. & Den Otter, C. 2002. Background odour induces adaptions and sensitization of olfactory receptors in the antennae of houseflies. Medical and Veterinary Entomology, 16,2: 161–169.
- Kettle, D.S., 1990. Muscidae (houseflies, stable flies). In Medical and Veterinary Entomology: 223–240.
- Khamesipour, F., Lankarani, K.B., Honarvar, B. & Kwenti, T.E. 2018. A systematic review of human pathogens carried by the housefly (Musca domestica L.). BMC Public Health: 18: 1–15.
- Malik, A., Singh, N. & Satya, S., 2007. Housefly (Musca domestica): a review of control strategies for a challenging pest. Journal of Environmental Science and Health part B 42,4: 453–469.
- Marshall, S. 2006. Insects: their natural history and diversity. Buffalo, New York: Firefly Books Ltd.
- Moriya, K., Fujibayashi, T., Yoshihara, T., Matsuda, A., Sumi, N., Umezaki, N., Kurahashi, H., Agui, N., Wada, A. & Watanabe, H., 1999. Verotoxin‐producing Escherichia coli O157: H7 carried by the housefly in Japan. Medical and Veterinary Entomology 13,2: 214–216.
- Pont, A.C. 1981. The Linnaean species of the families Fanniidae, Anthomyiidae and Muscidae (Insecta: Diptera). Biological Journal of the Linnean Society 15,2: 165–175.
- Rahuma, N., Ghenghesh, K.S., Ben-Aissa, R., & Elamaari, A. 2005. Carriage by the housefly (Musca domestica) of multiple antibiotic-resistant bacteria that are potentially pathogenic to humans, in hospital and other urban environments in Misurata, Libya. Annals of Tropical Medicine Parasitology 99: 795–802.
- Robinson, A.S. & Hendrichs, J. 2005. Prospects for the future development and application of the sterile insect technique. In Sterile insect technique: principles and practice in area-wide integrated pest management, pp. 727–760. Dordrecht: Springer Netherlands.
- Sacca, G., 1964. Comparative bionomics in the genus Musca. Annual Review of Entomology 9: 341–358.
- Sherman, R.A., Hall, M.J.R. & Thomas. S. 2000. Medicinal maggots: an ancient remedy for some contemporary afflictions. Annual Review of Entomology 45: 55–81.
- Sherman, R.A. 2002. Maggot therapy for foot and leg wounds. The international journal of lower extremity wounds 1,2: 135–142.
- Sarwar, M., 2015. Insect vectors involved in mechanical transmission of human pathogens for serious diseases. International Journal of Bioinformatics and Biomedical Engineering 1,3: 300–306.
- World Health Organization (WHO). 1986. Vector control series: the housefly: training and information guide (No. WHO/VBC/86.937). World Health Organization.
- Yamamoto, R.T. & Jensen, E. 1967. Ingestion of feeding stimulants and protein by the fern housefly, Musca domestica L. Journal of insect physiology 13: 91–98.
Authors:
Veronica Phetla and Ivy Taetsane
E-mail: v.phetla@sanbi.org.za