firebug vs heteropterous insect

firebug and heteropterous insect both are nouns.

Word	Noun	Adjective	Verb	Adverb
firebug	Yes	No	No	No
heteropterous insect	Yes	No	No	No

As nouns, heteropterous insect is a hypernym of firebug; that is, heteropterous insect is a word with a broader meaning than firebug:

firebug: a true bug: brightly colored bug that can exude a stain
heteropterous insect: true bugs: insects whose forewings are membranous but have leathery tips

firebug (noun)	heteropterous insect (noun)
a true bug: brightly colored bug that can exude a stain	true bugs: insects whose forewings are membranous but have leathery tips
a criminal who illegally sets fire to property