1911 Encyclopædia Britannica/Fly

​FLY (formed on the root of the supposed original Teut. fleugan,to fly), a designation applied to the winged or perfect state ofmany insects belonging to various orders, as in butterfly (seeLepidoptera), dragon-fly (q.v.), may-fly (q.v.), caddis-fly (q.v.),&c.; also specially employed by entomologists to mean anyspecies of the two-winged flies, or Diptera (q.v.). In ordinaryparlance fly is often used in the sense of the common house-fly(Musca domestica); and by English colonists and sportsmenin South Africa in that of a species of tsetse-fly (Glossina), or atract of country (“belt”) in which these insects abound (seeTsetse-Fly).

Apart from the house-fly proper (Musca domestica), which inEngland is the usual one, several species of flies are commonlyfound in houses; e.g. the Stomoxys calcitrans, or stable-fly;Pollenia rudis, or cluster-fly; Muscina stabulans, another stable-fly;Calliphora erythrocephala, blue-bottle fly, blow-fly or meat-fly,with smaller sorts of blue-bottle, Phormia terraenovae andLucilia caesar; Homalomyia canicularis and brevis, the smallhouse-fly; Scenopinus fenestralis, the black window-fly, &c.But Musca domestica is far the most numerous, and in manyplaces, especially in hot weather and in hot climates, is a regularpest. Mr L. O. Howard (Circular 71 of the Bureau of EntomologyU.S. Dept. of Agriculture, Washington, 1906) says that in 1900he made a collection of the flies in dining-rooms in different partsof the United States, and out of a total of 23,087 flies, 22,808were the common house-fly. Its geographical distribution isof the widest, and its rapidity of breeding, in manure and door-yardfilth, so great that, as a carrier of germs of disease, especiallycholera and typhoid, the house-fly is now recognized as a potentsource of danger; and various sanitary regulations have beenmade, or precautions suggested, for getting rid of it. These arediscussed by Mr Howard in the paper referred to, but in briefthey all amount to measures of general hygiene, and the isolation,prompt removal, or proper sterilization of the animal or humanexcrement in which these flies breed.