RES Handbook Vol 9 Part 2 iii. Diptera - 2. Nematocera: families Tipulidae to Chironomidae (Chironomidae)

FLIES of the family CHIRONOMIDAE may be distinguished from other Nematocerous families of Diptera by the following combination of characters: ocelli absent; antennae hairy (especially in male); six to eight veins reaching wing-margin; one or both anal veins not reaching margin; vein M simple; cross-veins R-M and M-CU (latter when present) near middle of wing. The reduced mouthparts and the fact that the costa is not continued around the entire wing provide simple distinctions from CULICIDAE, to which family some groups bear a superficial resemblance. The closely-related CERATOPOGONIDAE ("biting midges") were formerly included in the CHIRONOMIDAE ("non-biting midges"), and differ most obviously by the forked vein M; head rounded behind instead of flattened; postnotum without a distinct median longitudinal furrow or keel, which is present in most CHIRONOMIDAE.