this owns dude

Nevermind the loincloth. Why is she holding a sword when her upper arms are literally bladed horrors of sharp pains?

you can never have enough stabbing power.

Because carapace isn't as hard as steel? If the other person is using a sword or an axe, it's good to have something to parry with.

She wears a disguise to look like human guys but she's not a man she's a bug waifu

SHE'S A GIANT CHICKEN I TELL YOU

Makes the mammals nervous and confused if no loincloth

*inserts finger into mantis butt* why do they feel so fun :D

The loincloth is there because even if there's nothing there to hide, doesn't mean insects like people staring at their weak points. A good stab or kick there might hurt even *with* a carapace... it is the joint of a lot of body parts. Covering it makes it a little less easy to score a direct hit. Or maybe they're just modest about that part of their body, genitals or not.

Just keep the mantis chicks coming and I will love you forever

Excellent character design, here's hoping to see more of her in the future. As for the loincloth, chances are that females probably are not mainstream fashion doll featureless, and have some manner of chitinous vulva hidden beneath. As a people they probably have some social ways which would prohibit the baring of genitals, or perhaps it is done in consideration of the ways of others, or it may be worn to prevent dust, grit, dirt, etc from getting into chitinous naughty bits.
--Onni