bed bug vs hemipteron

bed bug and hemipteron both are nouns.

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

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

bed bug: bug of temperate regions that infests especially beds and feeds on human blood
hemipteron: insects with sucking mouthparts and forewings thickened and leathery at the base; usually show incomplete metamorphosis

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

bed bug (noun)	hemipteron (noun)
bug of temperate regions that infests especially beds and feeds on human blood	insects with sucking mouthparts and forewings thickened and leathery at the base; usually show incomplete metamorphosis