lepidopteran vs moth

lepidopteran and moth both are nouns.

Word	Noun	Adjective	Verb	Adverb
lepidopteran	Yes	No	No	No
moth	Yes	No	No	No

As nouns, moth is a hyponym of lepidopteran; that is, moth is a word with a more specific, narrower meaning than lepidopteran:

lepidopteran: insect that in the adult state has four wings more or less covered with tiny scales
moth: typically crepuscular or nocturnal insect having a stout body and feathery or hairlike antennae

Other hyponyms of lepidopteran include butterfly.

lepidopteran (noun)	moth (noun)
insect that in the adult state has four wings more or less covered with tiny scales	typically crepuscular or nocturnal insect having a stout body and feathery or hairlike antennae