I'm not aware of any way to tell the two species of Doroneuria apart as nymphs, so this one is classified to species based on location alone. Doroneuria baumanni is found in the Cascades and in Washington, and the other species is not known here yet.
The Jodea is EPIC. I got one a month ago and I will tell all you that if you like having a portable carrier that you can not lose this is it. Handling mayflies is tricky when you are seriously collecting for science and sometimes people may like small independant containers. But if you fly fish and collect a few every trip to post here, the Jodea is exactly what you need. I told Jeremiah I was going to give him excellent input towards considering another model of the same unit that is geared to the serious collector guy like me.
I even have a Canadian store chain that has looked at it with interest.
The black flies have forced me to just collecting so far. But in a few weeks I will be up north and fishing YEEeeee. I am going to film a HD video on this product to show how we in north America would use it. It is so well made you would not believe me until you see it. www.thejodea.com