brown-tail moth vs tussock moth

brown-tail moth and tussock moth both are nouns.

Word	Noun	Adjective	Verb	Adverb
brown-tail moth	Yes	No	No	No
tussock moth	Yes	No	No	No

As nouns, tussock moth is a hypernym of brown-tail moth; that is, tussock moth is a word with a broader meaning than brown-tail moth:

brown-tail moth: small brown and white European moth introduced into eastern United States; pest of various shade and fruit trees
tussock moth: dull-colored moth whose larvae have tufts of hair on the body and feed on the leaves of many deciduous trees

Other hypernyms of brown-tail moth include lymantriid.

brown-tail moth (noun)	tussock moth (noun)
small brown and white European moth introduced into eastern United States; pest of various shade and fruit trees	dull-colored moth whose larvae have tufts of hair on the body and feed on the leaves of many deciduous trees