Smallest true fly (dipteran)

The world's smallest species of true fly (dipteran) is Euryplatea nanaknihali. Formally described and named as recently as 2012, and measuring only 0.4 mm long, this minute insect is native to Thailand, and its larva parasitises acrobat ants of the genus Crematogaster. Eggs laid inside the living bodies of these ants by adult female flies hatch into larvae that then devour the hapless ant hosts internally as they mature before finally emerging as adults from the ants' decapitated bodies.