Working on a Race

[rferries]

Child-sized. Wide, luminous eyes. Pronounced canines. Green-blue skin. Dressed in iridescent chitin.

I get the impression that members of this race are very much like vermin themselves, in spite of their hatred of arthropods. You are what you eat, I guess! :D

Here are some suggestions:

Ability score bonus: +2 Con (hardy enough to withstand disgusting meals, swarm distraction, and vermin venom, as you've already noted), or +2 Dex (Small sized and nimble), or +2 Wis (like standard Vermin)

Ability score penalty: -2 Charisma (uncharismatic as standard vermin), or -2 Int (stupid as standard vermin), or -2 Str (due to Small stature)

Bug-Eyed: Bonus on Spot and/or Search checks

Darkvision 60 ft (like standard vermin)

Bite attack (pronounced canines)

Natural Armor +1 (inherent chitin? or they just wear it?)

Favoured Enemy (Vermin) or racial bonuses to attacks and AC against vermin (as a dwarf against giants)

Damage reduction vs swarm attacks, and/or swarms aren't immune to their weapon damage?

Scent?

It's possible I misread the intent of your post - did you want racial abilities, or background lore?