Diptera(two-winged flies, true flies; class Insecta, subclass Pterygota) Order of insects in which the adults have a single pair of membranous wings, the hind wings having been modified into halteres. The mouth-parts are generally adapted for sucking, and modified into a proboscis, often adapted for piercing. Mandibles are absent in many families. Metamorphosis is complete. Larvae lack true legs and are eruciform, with up to 12 abdominal segments. Larval habits range from phytophagy to parasitism. The number of larval instars ranges from three (Cyclorrapha) to eight (Brachycera). The order is one of the largest within the class, having more than 85 000 described species. Most authors recognize three suborders: Nematocera (21 families), Brachycera (15 families), and Cyclorrapha (57 families).

Diptera An order of insects comprising the true, or two-winged, flies. Flies possess only one pair of wings – the forewings; the hindwings are modified to form small clublike halteres that function as balancing organs. Typically fluid feeders, flies have mouthparts adapted for piercing and sucking or for lapping; the diet includes nectar, sap, decaying organic matter, and blood. Some species prey on insects; others are parasitic. Dipteran larvae (maggots) are typically wormlike with an inconspicuous head. They undergo metamorphosis via a pupal stage to the adult form. Many flies or their larvae are serious pests, either by feeding on crops (e.g. fruit flies) or as vectors of disease organisms (e.g. the house fly (Musca domestica) and certain mosquitoes).

diptera two-winged flies. XIX. — Gr. díptera, n. pl. of dipteros two-winged (f. DI- 2 + pterón wing) used sb.
So dipterous XVIII.