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 female Hendrickson spinner is in kind of bad shape, but at least now I've got some good closeup photos of one. I collected her and a male Hendrickson as duns from the same hatch, and both molted into spinners in my house within a couple of days.
This mayfly was collected from Fall Creek in New York on April 23rd, 2007 and added to Troutnut.com by Troutnut on April 25th, 2007.