spruce gall aphid vs adelgid

spruce gall aphid and adelgid both are nouns.

Word	Noun	Adjective	Verb	Adverb
spruce gall aphid	Yes	No	No	No
adelgid	Yes	No	No	No

As nouns, adelgid is a hypernym of spruce gall aphid; that is, adelgid is a word with a broader meaning than spruce gall aphid:

spruce gall aphid: a variety of adelgid which is a pest of the Norway spruce and various North American spruces, especially the white spruce and black spruce (Adelges abietis)
adelgid: any of various insects that feed and form galls on conifers

spruce gall aphid (noun)	adelgid (noun)
a variety of adelgid which is a pest of the Norway spruce and various North American spruces, especially the white spruce and black spruce (Adelges abietis)	any of various insects that feed and form galls on conifers