We didn't have a single term around here.

Most common was punkin bug, or pumpkin bug for you damn yankees.

But, roly-poly, tomato bug, and pill bug were all in common usage.

What's interesting to me is that they were also called doodle bugs, despite a completely different bug also being called that. Doodle bug is also used for ant lions around here; indeed, that's what they're called almost exclusively.

They were both called that for the same reason, the little doodly tracks they leave in fine sand and soil, though if a punkin bug is on that, they're going elsewhere because they don't really like those conditions.