Field Guide - Cut Worm
Typical cut worm damage on the foliage will appear as leaves being cut off and laying on the ground. By digging at the base of the potato plant that has the “cut off” leaves, you will be able to find the cut worm in the soil.
Cut worms are nocturnal feeders and hide in the soil during the day.
Cut worms are capable of damaging potato tubers by feeding directly on the tubers.