Fly

Flies are insects of the order Diptera, the name being derived from the Greek δι- di- "two", and πτερόν pteron "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics.[1] Diptera is a large order containing an estimated 1,000,000 species including horse-flies,[a] crane flies, hoverflies and others, although only about 125,000 species have been described.[4]

Diversity

Flies are often abundant and are found in almost all terrestrial habitats in the world apart from Antarctica. They include many familiar insects such as house flies, blow flies, mosquitoes, gnats, black flies, midges and fruit flies. More than 150,000 have been formally described and the actual species diversity is much greater, with the flies from many parts of the world yet to be studied intensively.[17][18] The suborder Nematocera include generally small, slender insects with long antennae such as mosquitoes, gnats, midges and crane-flies, while the Brachycera includes broader, more robust flies with short antennae. Many nematoceran larvae are aquatic.[19] There are estimated to be a total of about 19,000 species of Diptera in Europe, 22,000 in the Nearctic region, 20,000 in the Afrotropical region, 23,000 in the Oriental region and 19,000 in the Australasian region.[20] While most species have restricted distributions, a few like the housefly (Musca domestica) are cosmopolitan.[21] Gauromydas heros (Asiloidea), with a length of up to 7 cm (2.8 in), is generally considered to be the largest fly in the world,[22] while the smallest is Euryplatea nanaknihali, which at 0.4 mm (0.016 in) is smaller than a grain of salt.[23]

Human interaction and cultural depictions

Flies are a health hazard and are attracted to toilets because of their smell. The New Scientist magazine suggested a trap for these flies. A pipe acting as a chimney was fitted to the toilet which let in some light to attract these flies up to the end of this pipe where a gauze covering prevented escape to the air outside so that they were trapped and died. Toilets are generally dark inside particularly if the door is closed.