The housefly (Musca domestica) is a fly of the suborder Cyclorrhapha.
It is the most common fly species found in houses.
Adults are gray to black, with four dark, longitudinal lines on the thorax, slightly hairy bodies, and a single pair of membranous wings.
They have red eyes, set farther apart in the slightly larger female.
The female usually mates only once and stores the sperm for later use.
The female housefly lays batches of about 100 eggs on decaying organic matter such as food waste, carrion, or feces.
Eggs soon hatch into legless white larvae, known as maggots.
After two to five days of development, maggots metamorphose into reddish-brown pupae.
Adult flies normally live for two to four weeks, but can hibernate during the winter.
Adult flies feed on a variety of liquid or semi-liquid substances, as well as solid materials which have been softened by their saliva.
Adult flies carry pathogens on their bodies and in their feces, contaminate food, and contribute to the transfer of food-borne illnesses.
Adult houseflies are usually 6 to 7 mm long with a wingspan of 13 to 15 mm.
Females houseflies tend to be larger winged than males, while males have relatively longer legs.
The pair of large compound eyes almost touch in the male, but are more widely separated in the female.
They have three simple eyes (ocelli).
Houseflies process visual information around seven times more quickly than humans.
Housefly mouth parts are used for sucking up liquid food.
Housefly mandibles and maxillae are reduced and not functional, and the other mouthparts form a retractable, flexible proboscis with an enlarged, fleshy tip, the labellum.
The labellum is a sponge-like structure that is characterized by many grooves, called pseudotracheae, which suck up fluids by capillary action.
It distributed saliva to soften solid foods or collect loose particles.
Housefly chemoreceptors, the organs of taste, are on the tarsi of their legs, so they can identify foods such as sugars by walking over them.
Houseflies clean their legs by rubbing them together, enabling the chemoreceptors to taste afresh.
At the end of each housefly leg is a pair of claws, with two adhesive pads, pulvilli.
Pulvilli enable the housefly to walk up smooth walls and ceilings.
Housefly claws help the housefly to unstick the foot for the next step.
Houseflies walk on horizontal and vertical surfaces with three legs in contact with the surface and three in movement, but when walking on the ceiling. they alter the gait to keep four feet stuck to the surface.
Upon landing on a ceiling by flying straight towards it, they use all six legs at the surface, absorbing the shock with the front legs and sticking a moment later with the other four.
The housefly thorax is gray/black, with four dark, longitudinal bands of even width on the dorsal surface.
The housefly’s whole body is covered with short hairs.
Houseflies have only one pair of wings, which are translucent with a yellowish tinge at their base.
The abdomen has 10 segments which bear spiracles for respiration. In males, the ninth segment bears a pair of claspers for copulation, and the 10th bears anal cerci in both sexes.
The housefly is probably the insect with the widest distribution in the world.
The housefly is largely associated with humans and has accompanied them around the globe.
It is present in the Arctic, as well as in the tropics, and in all populated parts of Europe, Asia, Africa, Australasia, and the Americas.
Female houseflies can lay up to 500 eggs in their lifetime.
They lay several batches of about 75 to 150 eggs.
The eggs are about 1.2 mm (1⁄16 in) in length, and they are deposited usually in dead and decaying organic matter, such as food waste, carrion, or feces.
Within a day, larvae, maggots, hatch from the eggs; they live and feed where they were laid.
Maggots are whitish, 3 to 9 mm (1⁄8 to 11⁄32 in) long, thinner at the mouth end, and legless.
Larval development takes from two weeks, under optimal conditions.
Development can take 30 days or more in cooler conditions.
The larvae avoid light.
Animal manure provides nutrient-rich sites and ideal growing conditions, being warm, moist, and dark.
Larvae crawl to a dry, cool place and transform into pupae.
Pupae complete their development in two to six days at 35 °C (95 °F), but may take 20 days or more at 14 °C (57 °F).
With metamorphosis complete, the adult housefly emerges from the pupa.
The life expectancy of a housefly is generally 15 to 30 days and depends upon temperature and living conditions.
A small fly is not necessarily a young fly.
A small fly is result of getting insufficient food during the larval stage.
Male houseflies are sexually mature after 16 hours and females after 24.
Females produce a pheromone, sensed by males only on contact with females.
Males initiates mating by bumping into the female, in the air or on the ground, known as a “strike”.
The female pushes her ovipositor into his genital opening; copulation, with sperm transfer, lasting for several minutes.
Females normally mate only once and then reject further advances from males, while males mate multiple times.
A volatile chemical that is deposited by females on their eggs to attractother gravid females and leads to clustered egg deposition.
The larvae development depends on warmth and sufficient moisture to develop; the warmer the temperature, the faster they grow.
The life cycle can be completed in seven to 10 days under optimal conditions., but may take up to two months in less beneficial circumstances.
In temperate regions, 12 generations of houseflies may occur per year, and in the tropics and subtropics, more than 20.
Houseflies break down and recycle organic matter.
Adults are mainly carnivorous; primary food is animal matter, carrion, and feces, but they also consume milk, sugary substances, and rotting fruit and vegetables.
Solid foods are softened with saliva before being sucked up.
Klebsiella oxytoca bacteria, can live on the surface of housefly eggs and deter fungi which compete with the housefly larvae for nutrients.
Adult houseflies are diurnal and rest at night.
After dark houseflies tend to congregate on ceilings, beams, overhead wires, and while out of doors, they crawl into foliage or long grass, or rest in shrubs and trees or on wires.
Some houseflies hibernate in winter, choosing to do so in cracks and crevices.
Hibernating houseflies arouse in the spring and search out a place to lay their eggs.
Housefly predators include: birds, reptiles, amphibians, various insects, and spiders.
The eggs, larvae, and pupae have many stage-specific parasites and parasitoids.
Housefly are killed by the pathogenic fungus.
Houseflies sometimes carry mites.
A virus that causes enlargement of the salivary glands, salivary gland hypertrophy virus (SGHV), is spread among houseflies through contact with food and infected female houseflies.
Houseflies are a nuisance.
They contaminate foodstuffs: by breeding and feeding in dirty places, and feeding on human foods, during which process they soften the food with saliva and deposit their feces, creating a health hazard.
Houseflies can fly for several kilometers from their breeding places.
They carry a wide variety of organisms on their hairs, mouthparts, vomitus, and feces.
Parasites carried include cysts of protozoa- Entamoeba histolytica and Giardia lamblia and eggs of helminths-Ascaris lumbricoides, Trichuris trichiura, Hymenolepis nana, and Enterobius vermicularis.
Houseflies do not serve as a secondary host or act as a reservoir of any bacteria of medical importance.
Houseflies serve as mechanical vectors to over 100 pathogens, such as those causing typhoid, cholera, salmonellosis, bacillary dysentery, tuberculosis, and anthrax, and pyogenic cocci.
Disease-causing organisms on the outer surface of the housefly may survive for a few hours, but those in the crop or gut can be viable for several days.
There are too few bacteria are on the external surface of the houseflies, except perhaps for Shigella, to cause infection, so the main routes to human infection are through the housefly’s regurgitation and defecation.
Houseflies can be controlled, at least to some extent, by physical, chemical, or biological means.
Physical controls include: screening with small mesh, vertical strips of plastic or strings of beads in doorways, fans to create air movement or air barriers.
Fly-killing devices: sticky fly papers hanging from the ceiling
are effective,bug zappers.
Elimination as far as possible of potential breeding sites: Keeping garbage in lidded containers and collecting it regularly and frequently, prevents any eggs laid from developing into adults.
Insecticides:Many strains of housefly have become immune to the most commonly used insecticides.
Introduction of another species, the black soldier fly, whose larvae compete with those of the housefly for resources.
Churning up the surface of a manure heap and render it unsuitable for breeding with dung beetles.
Augmentative biological control by releasing parasitoids.