larva vs fauna

larva and fauna both are nouns.

Word	Noun	Adjective	Verb	Adverb
larva	Yes	No	No	No
fauna	Yes	No	No	No

As nouns, fauna is a hypernym of larva; that is, fauna is a word with a broader meaning than larva:

larva: the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose
fauna: a living organism characterized by voluntary movement

Other hypernyms of larva include animal, animate being, beast, brute, creature.

larva (noun)	fauna (noun)
the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose	a living organism characterized by voluntary movement
	all the animal life in a particular region or period