Flies
The presence of a single pair of patent, metathoracic flight wings distinguishes true flies from other insects with "fly" in their names. The Diptera comprise a large order, containing an estimated 240,000 species of mosquitoes, gnats, midges and others, although under half of these (about 120,000 species) have been described. It is one of the major insect orders both in terms of ecological and human (medical and economic) importance.
