gall midge vs gallfly

gall midge and gallfly both are nouns.

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

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

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

Other synonyms of gall midge include gall gnat.

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