orthopterous insect vs orthopteran

orthopterous insect and orthopteran both are nouns.

Word	Noun	Adjective	Verb	Adverb
orthopterous insect	Yes	No	No	No
orthopteran	Yes	No	No	No

As nouns, orthopterous insect and orthopteran are synonyms defined as:

orthopterous insect and orthopteran: any of various insects having leathery forewings and membranous hind wings and chewing mouthparts

Other synonyms of orthopterous insect include orthopteron.

orthopterous insect (noun)	orthopteran (noun)
any of various insects having leathery forewings and membranous hind wings and chewing mouthparts	any of various insects having leathery forewings and membranous hind wings and chewing mouthparts