buffalo gnat vs blackfly

buffalo gnat and blackfly both are nouns.

Word	Noun	Adjective	Verb	Adverb
buffalo gnat	Yes	No	No	No
blackfly	Yes	No	No	No

As nouns, buffalo gnat and blackfly are synonyms defined as:

buffalo gnat and blackfly: small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals

Other synonyms of buffalo gnat include black fly.

buffalo gnat (noun)	blackfly (noun)
small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals	small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals
	blackish aphid that infests e.g. beans and sugar beets