woolly aphid vs woolly plant louse

woolly aphid and woolly plant louse both are nouns.

Word	Noun	Adjective	Verb	Adverb
woolly aphid	Yes	No	No	No
woolly plant louse	Yes	No	No	No

As nouns, woolly aphid and woolly plant louse are synonyms defined as:

woolly aphid and woolly plant louse: secretes a waxy substance like a mass of fine curly white cotton or woolly threads

woolly aphid (noun)	woolly plant louse (noun)
secretes a waxy substance like a mass of fine curly white cotton or woolly threads	secretes a waxy substance like a mass of fine curly white cotton or woolly threads