The Woodlice guide page says they sometimes eat live plants. Whatever's eating these leaves does it at night. Other leaf eaters may also work on the potato plants. I didn't catch these creatures in the act of taking a bite, but clearly they don't like light. Most of them evaded my strong flashlight.

Maybe they can't see red light. Cover your flashlight with a piece of red cellophane. At least that is what we did when we were tracking egg-laying turtles in Costa Rica.

It's a lantern-type flashlight, and it provided some of the illumination for photos--the rest was the flash. I may be able to enclose it in something red while skulking around looking for bugs, but the photos need white light.