Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
This specimen was completely green when I collected it from among many others gathered on a midstream rock along with their nymphal shucks early in the morning. There was also a yellow one with them, which I assumed was a different species. Now that I've seen how this one started changing from green to yellow, I have to wonder if they weren't the same species and the yellow one was just older.
This stonefly was collected from Brodhead Creek in Pennsylvania on May 29th, 2007 and added to Troutnut.com by Troutnut on June 4th, 2007.