fall armyworm vs Spodoptera frugiperda

fall armyworm and Spodoptera frugiperda both are nouns.

Word	Noun	Adjective	Verb	Adverb
fall armyworm	Yes	No	No	No
Spodoptera frugiperda	Yes	No	No	No

As nouns, fall armyworm and Spodoptera frugiperda are synonyms defined as:

fall armyworm and Spodoptera frugiperda: larva of a migratory American noctuid moth; destroys grasses and small grains

fall armyworm (noun)	Spodoptera frugiperda (noun)
larva of a migratory American noctuid moth; destroys grasses and small grains	larva of a migratory American noctuid moth; destroys grasses and small grains
	moth whose larvae are fall armyworms