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.
The striking coloration of this Ephemerella nymph earned it a turn under the camera lens. It has a different look than others I've collected, but I still might tentatively guess it belongs to the widely variable (and ironically named) invaria species.
This mayfly was collected from Cayuta Creek in New York on April 14th, 2007 and added to Troutnut.com by Troutnut on April 22nd, 2007.