The document discusses the order Diptera, which includes flies and mosquitoes. It has 3 suborders - Nematocera, Brachocera, and Cyclorrhapha - which are distinguished based on antennae structure, mesopleural structure, presence of disc cell, and cubital wing vein closure. Nematocera contains 6 families including craneflies, sandflies, mosquitoes, midges, fungus gnats, and black flies. Brachocera contains 3 families - horse flies, robber flies, and bee flies. Cyclorrhapha contains 7 families such as hoverflies, fruit flies, drosophila, bot flies, house flies, warble flies, and