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 has tarsal claws with 7 denticles and tubercles on abdominal segments 4-7 only. It keys to Serratella micheneri, as do some other specimens from the same collection that lacked the dorsal stripe.
This mayfly was collected from Mystery Creek #199 in Washington on July 28th, 2019 and added to Troutnut.com by Troutnut on July 30th, 2019.