caseworm vs caddisworm

caseworm and caddisworm both are nouns.

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

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

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

Other hyponyms of caseworm include strawworm.

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