A two-winged insect in the order Diptera. Important flies include Simulium (black fly), Calliphora (bluebottle fly), Piophila casei (cheese fly), Chrysops (deer fly), Siphona irritans (horn fly), Fannia scolaris (latrine fly), Oestrus ovis and Gasterophilus hemorrhoidalis (nose fly), Cochliomyia hominivorax (primary screw-worm fly) and C. macellaria (secondary screw-worm fly), Stomoxys calcitrans (stable fly), Glossina (tsetse fly), and members of the insect order Trichoptera. For some types of flies not listed as subentries here (usually written as one word), see the full name (e.g., blowfly, botfly, gadfly, horsefly, housefly). [A.S. fleóge]