gallfly vs gall midge

gallfly and gall midge both are nouns.

Word	Noun	Adjective	Verb	Adverb
gallfly	Yes	No	No	No
gall midge	Yes	No	No	No

As nouns, gallfly and gall midge are synonyms defined as:

gallfly and gall midge: fragile mosquito-like flies that produce galls on plants

Other synonyms of gallfly include gall gnat.

gallfly (noun)	gall midge (noun)
any of various insects that deposit their eggs in plants causing galls in which the larvae feed	fragile mosquito-like flies that produce galls on plants
small solitary wasp that produces galls on oaks and other plants
fragile mosquito-like flies that produce galls on plants