underwing vs noctuid moth

underwing and noctuid moth both are nouns.

Word	Noun	Adjective	Verb	Adverb
underwing	Yes	No	No	No
noctuid moth	Yes	No	No	No

As nouns, noctuid moth is a hypernym of underwing; that is, noctuid moth is a word with a broader meaning than underwing:

underwing: moth having dull forewings and brightly colored hind wings
noctuid moth: usually dull-colored medium-sized nocturnal moth; the usually smooth-bodied larvae are destructive agricultural pests

Other hypernyms of underwing include noctuid, owlet moth.

underwing (noun)	noctuid moth (noun)
moth having dull forewings and brightly colored hind wings	usually dull-colored medium-sized nocturnal moth; the usually smooth-bodied larvae are destructive agricultural pests