hymenopteran vs hymenopterous insect

hymenopteran and hymenopterous insect both are nouns.

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

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

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

Other synonyms of hymenopteran include hymenopter, hymenopteron.

hymenopteran (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