lygaeid vs chinch bug

lygaeid and chinch bug both are nouns.

Word	Noun	Adjective	Verb	Adverb
lygaeid	Yes	No	No	No
chinch bug	Yes	No	No	No

As nouns, chinch bug is a hyponym of lygaeid; that is, chinch bug is a word with a more specific, narrower meaning than lygaeid:

lygaeid: a true bug: usually bright-colored; pest of cultivated crops and some fruit trees
chinch bug: small black-and-white insect that feeds on cereal grasses

Other hyponyms of lygaeid include Blissus leucopterus.

lygaeid (noun)	chinch bug (noun)
a true bug: usually bright-colored; pest of cultivated crops and some fruit trees	small black-and-white insect that feeds on cereal grasses