gallfly

(noun) small solitary wasp that produces galls on oaks and other plants. Synonyms: gall wasp, cynipid wasp, cynipid gall wasp.

(noun) fragile mosquito-like flies that produce galls on plants. Synonyms: gall midge, gall gnat.

(noun) any of various insects that deposit their eggs in plants causing galls in which the larvae feed.