hymenopter vs hymenopterous insect

hymenopter and hymenopterous insect both are nouns.

Word	Noun	Adjective	Verb	Adverb
hymenopter	Yes	No	No	No
hymenopterous insect	Yes	No	No	No

As nouns, hymenopter and hymenopterous insect are synonyms defined as:

hymenopter and hymenopterous insect: insects having two pairs of membranous wings and an ovipositor specialized for stinging or piercing

Other synonyms of hymenopter include hymenopteran, hymenopteron.

hymenopter (noun)	hymenopterous insect (noun)
insects having two pairs of membranous wings and an ovipositor specialized for stinging or piercing	insects having two pairs of membranous wings and an ovipositor specialized for stinging or piercing