Those worms have become somewhat common in the US and will do fine here. The nightcrawlers are kind of aggressive though and as I understand, you wouldn't want to put them in the same bin with red wigglers. Someone here on this forum a while back said that they would kill the smaller worms.

I had mostly nightcrawlers in my yard up in Colorado and very few of any other type, so that could be the reason for that. I have very few nightcrawlers here in Texas, and many red wigglers. But I have mostly some weird kind of whitish earthworms, about 6-8" long. I haven't figured out yet what they are. But I have introduced red wigglers to my soil and they have stayed around, and I have more. In fact they're breeding like rabbits in my rose garden. I'm sure your nightcrawlers would be fine. Cheryl

Hi Seamommy; the information on nightcrawlers being aggressive is at best misinformation. The common earthworms in any given temperate zone will co-exist with other earthwotms. Each has its nitch in which it looks for food and shelter from its enemies. Earthworms only eat dead organic decomposing materials. The microbes are its living source of food.
Earthworms have common enemies.

Here is a link that might be useful: earthworm enemies