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.
You won't catch any of the little spinner-sippers, but what you do catch might make you question why you've spent so much time and energy fussing with little fish in the darkness!
I think you guys owe him a 6 pack of virtual beers....