Cold tolarance difference

[MasSalvaje]

I'm guessing this is because they range much farther north than T.radix

I would say that their range goes farther North because they can tolerate the colder temps, not the other way around.

Should I brumate the parietalis at a lower temp.

I do not have experience with the parietalis but I would think that they would do just fine in the same temps as the radix. I know they have been documented at the same dens so I can't imagine them needing different temps.

-Thomas