Only one real line John?
Care to elaborate?
I'd say the same goes for the UK mate.
As of late I've been seeing tonnes of suspect Terribilis which I'm almost 100% sure are the result of Yellows and Mints being housed together.
Historically there were few exports (illegal or legal) from Colombia, so the real terribilis that we have are likely all descended from very few groups. The yellow terribilis and orange terribilis (not sure about mints but probably them as well) in the US came from Europe, so we're all in the same boat.
Mixing-wise, I firmly believe that there has been a lot of hybridization of yellow terribilis with yellow bicolor. I've been sold such frogs as yellow terribilis here in the US, and having the genuine article already, I was immediately suspicious of these animals.
On the subject of mints and yellows hybridizing, I recently spoke to Marcus Breece here in the US (he of SNDF) and he said something very similar to what you have brought up - he doesn't seem to think there are many genuine mints in the US.
The male calls an awful lot, and while the females seemingly react by increased movement, no courtship has been witnessed so far.
Can I ask what the ideal spawning sites are for these guys? I've got a couple of petri dishes with minimal - no water underneath the 'huts'.
My yellows did not lay eggs for the first time until they were 18-19 months old. They didn't produce viable eggs until they were 21-22 months old. So you have some waiting to do. Petri dishes under coconut huts seem to work fine. Mine have only laid outside a couple of times, and always on a large aroid leaf.