bladder worm vs larva

bladder worm and larva both are nouns.

Word	Noun	Adjective	Verb	Adverb
bladder worm	Yes	No	No	No
larva	Yes	No	No	No

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

bladder worm: encysted saclike larva of the tapeworm
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

bladder worm (noun)	larva (noun)
encysted saclike larva of the tapeworm	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