Cecidomyiidae

thumb|right|A cecidomyiid laying eggs on grass thumb|thumbtime=0:51|Cecidomyiid in copula thumb|thumbtime=1:40|Cecidomyiid oviposting into boreholes of bark beetles on a fallen beech

Cecidomyiidae is a family of flies known as gall midges or gall gnats. As the name implies, the larvae of most gall midges feed within plant tissue, creating abnormal plant growths called galls. Cecidomyiidae are very fragile small insects usually only in length; many are less than long. They are characterised by hairy wings, unusual in the order Diptera, and have long antennae. Some Cecidomyiids are also known for the strange phenomenon of paedogenesis in which the larval stage reproduces without maturing first. In some species, the daughter larvae consume the mother, while in others, reproduction occurs later on in the egg or pupa.