caseworm vs strawworm

caseworm and strawworm both are nouns.

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

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

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

Other hyponyms of caseworm include caddisworm.

caseworm (noun)	strawworm (noun)
insect larva that constructs a protective case around its body	larva of chalcid flies injurious to the straw of wheat and other grains
	larva of the caddis fly; constructs a case of silk covered with sand or plant debris