plant bug vs hemipteron

plant bug and hemipteron both are nouns.

Word	Noun	Adjective	Verb	Adverb
plant bug	Yes	No	No	No
hemipteron	Yes	No	No	No

As nouns, hemipteron is a hypernym of plant bug; that is, hemipteron is a word with a broader meaning than plant bug:

plant bug: small bright-colored insect that feeds on plant juices
hemipteron: insects with sucking mouthparts and forewings thickened and leathery at the base; usually show incomplete metamorphosis

Other hypernyms of plant bug include bug, hemipteran, hemipterous insect.

plant bug (noun)	hemipteron (noun)
small bright-colored insect that feeds on plant juices	insects with sucking mouthparts and forewings thickened and leathery at the base; usually show incomplete metamorphosis