How many eyes does a housefly have?

Copulating houseflies

The Housefly (Musca domestica from lat. musca "Fly", domus "House"), too Common housefly or Big housefly (to distinguish it from the small housefly), is a fly from the family of real flies (Muscidae).

features

The body structure generally corresponds to that of the real flies family. Size, color and wing veining serve as morphological distinguishing features to other species. They have licking-sucking mouthparts. Adult houseflies are six to seven millimeters long, their bodies are gray and have four longitudinal stripes on the thorax. The underside of the trunk is yellowish, its extremities are black, the body is completely covered with hair. They have red compound eyes. The bodies of female flies are slightly larger and their eye relief is usually slightly larger than that of male specimens. In the rest position, the wings are spread at a narrow angle. Because of their similar appearance to common biting flies, they can easily be confused with these.

Occurrence

Musca domestica occurs almost everywhere in the world (cosmopolitan), it is only not found in deserts, polar and high alpine landscapes. Their distribution is mostly associated with humans, as this is where the greatest food supply prevails.

Houseflies are used, among other things, for research purposes and as animal feed[1] bred.

Way of life

The housefly lives 6 to 42 days depending on the ambient temperature and food availability, with females usually living a little longer than males. The flight speed is about 2.9 meters per second, the fly flaps its wings about 180-330 times per second.[2] Flies can smell butyric acid as an indication of putrefaction and intestinal excretions. They have chemoreceptors on the distal limbs that enable them to taste sugar. They lay their eggs in putrefactive substances and excrement (coprophagia), on which the larvae feed. The adults suck on all nutritious liquids and also on solid, water-soluble substances that they can dissolve with the help of their saliva, such as sugar. Their behavior and their service life are very dependent on the ambient conditions such as temperature and humidity, with the optimum temperature between 20-25 ° C and immobilization taking place from a minimum temperature of 15 ° C. This also explains the development to a diurnal temporal specialist with the largest population size in the summer months.

Reproduction and development

As holometabolic insects, the house flies go through a complete metamorphosis, which is divided into egg, three larval stages, pupa and imago. The females lay their eggs in decomposing organic material such as manure, garbage, compost and food. The larvae then develop there. During the summer months, females lay between 150–400 eggs several times per oviposition with an interval of three to four days.[3] Due to good environmental conditions, which are given in stables, for example, up to 15 generations per year are possible (plurivoltin).[4] It takes about 12 to 25 hours for the larvae to hatch in the eggs. The headless and legless fly maggots can move awkwardly with body curves, reach a size of 12 mm and feed on the organic material (substrate) on which they hatched. The nutrition is made possible by mouthparts with forceps-like mouth hooks, this implies at the same time breathing through skin breathing and spiracles, which are located at the end of the body. After moulting twice in the course of growth, at the end of the third larval stage, the contents of the digestive tract are emptied and the maggots begin to immobilize as a result of genetic changes. Their skin hardens and the larvae develop into barrel pupae, which are significantly smaller and darker than the larvae. A transformation begins within such a doll, which takes 3 to 8 days depending on the temperature. After the development is complete, the so-called arched seam on her head is pressed into a bubble for hatching, which enables the adults to leave the doll through an opening at the head end (hatchers). Just 3 days after this act of hatching, the houseflies mate and then the females are ready to lay their first eggs. The metamorphosis from egg to fly can be completed in 7 days under good environmental conditions, but in our latitudes it takes an average of 2 to 3 weeks.[5] Mating is already possible after 3 days, although apart from the hibernating animals, the lifespan is only a few weeks.

The housefly - benefit and harm

The housefly as a disease vector

House flies are generally considered pests because they serve as vectors for pathogens despite being cleaned. For example, they are carriers of various infectious diseases such as dysentery, typhus, cholera, salmonellosis, polio, foot-and-mouth disease and others. Because of this, the excretions of the flies should be mentioned in particular.

Their function as a disease transmitter is due to their food sources, as they have a preference for human and animal body excretions such as sweat and feces as well as festering wounds. Furthermore, decaying human or animal carcasses (necrophagia) serve as a protein-rich food source for oviposition and larval development. A large-scale control would not necessarily be effective (→ insect protection), since on the one hand resistance to insecticides develops very quickly and the population size is contained by natural predators anyway.[6]

In order to limit the places of spread and transmission of diseases, all that is recommended is a sufficient standard of hygiene and clean handling of waste and decomposition products.

Fly maggots as a protein supplier

As a full substitute for protein-rich fish meal with protein from fly larvae meal, a company is breeding the species on the agricultural science site of the University of Stellenbosch in Elsenburg (South Africa) Musca domestica a million times. One kilogram of fly eggs can produce around 380 to 420 kilograms of protein in just 72 hours. With a corresponding large-scale production, a large part of the global fishmeal production could be saved and the world's oceans relieved of industrial fishing. The Agriprotein company plans to go into mass production in 2012.[1] 65 t of blood from conventional slaughterhouses are required to pull 100 t of fly larvae over a length of around 12 mm each, from which in turn 20 t of the protein product are obtained by drying, grinding and subsequent pelletizing. Another pilot plant in Germany is funded by the German government with 50%.[7]

literature

  • Jason H. Byrd & James L. Castner: Forensic Entomology. The Utility of Arthropods in Legal Investigations. Taylor & Francis Group, LLC 2010, ISBN 978-0-8493-9215-3
  • Wilfried Westheide & Reinhard Rieger (Eds): Special Zoology, Part 1. Gustav Fischer Verlag, 1996, ISBN 3-437-20515-3

See also

Web links

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Individual evidence

  1. 1,01,1Breeders produce alternative animal feed - the masters of the flies
  2. ↑ Wilfried Westheide & Reinhard Rieger (Eds): Special zoology. Part 1 edition. Gustav Fischer Verlag Jena, Jena 1996.
  3. ↑ Johannes Keiding: The housefly — biology and control. Training and information guide. World Health Organization, Vector Biology and Control Division, 1986.
  4. ↑ Wilfried Westheide & Reinhard Rieger (eds): Special zoology. Part 1 edition. Gustav Fischer Verlag Jena, Jena 1996.
  5. ↑ Heiko Joachim Koch: [http://benecke.com/pdf/koch_fe.pdf. 2002 (diploma thesis).
  6. ↑ Katharina Schmitt: [http://benecke.com/pdf/Katharina_Schmitt_Facharbeit_Forensische_Entomologie_Benecke_Com.pdf. 2010 (technical work).
  7. ↑ AgriProtein's managing director sees maggots as next protein alternative