browntail vs tussock moth

browntail and tussock moth both are nouns.

Word	Noun	Adjective	Verb	Adverb
browntail	Yes	No	No	No
tussock moth	Yes	No	No	No

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

browntail: 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 browntail include lymantriid.

browntail (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