[1][2][3] Herbivorous species make up about 75% of the Cecidomyiinae; many are gall-inducers, infecting a wide diversity of plants.

They are found world-wide and are the most ecologically diverse gall-inducing group of organisms.

Larvae of these species attack other arthropods - there are known predators of mites, aphids, scale insects, dragonfly eggs, and endoparasitoids of Hemiptera.

[1][4] Fungivores make up much of the remainder of the subfamily, indicating the retention of (or reversion to) the ancestral food source.

[4] Cecidomyiinae is monophyletic and species of the subfamily can be distinguished from other Cecidomyiidae by characters of the male genitalia, the number of antennal segments, and bristles on the larval abdomen.