caddisworm vs caseworm

caddisworm and caseworm both are nouns.

Word	Noun	Adjective	Verb	Adverb
caddisworm	Yes	No	No	No
caseworm	Yes	No	No	No

As nouns, caseworm is a hypernym of caddisworm; that is, caseworm is a word with a broader meaning than caddisworm:

caddisworm: larva of the caddis fly; constructs a case of silk covered with sand or plant debris
caseworm: insect larva that constructs a protective case around its body

caddisworm (noun)	caseworm (noun)
larva of the caddis fly; constructs a case of silk covered with sand or plant debris	insect larva that constructs a protective case around its body