Originally posted by Zep Tepi:

Go back to the swamp and make a root chest piece. Despite the fact that the armor rating is lower, the pierce resist dramatically reduces mosquito damage, also works for spear fulings and seekers, but avoid fire.

This.

Piercing resistance is OP in the plains. You only need the chest piece to gain the resistance, so you can put armor pieces from other sets on the rest of your body.