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 one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
Millcreek on Jan 11, 2015January 11th, 2015, 7:07 am EST
These are Ecdyonurus nymphs with Symbiocladius parasitizing them. They were collected from Mill Creek, a tributary of the Russian River. Symbiocladius are a member of Diptera, the true flies. They attach themselves behind the wingpads and grow to maturity there without harming the Ecdyonurus nymph. They parasitize Paraleptophebia and Rhithrogena as well though not in this area.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
Entoman on Jan 11, 2015January 11th, 2015, 7:56 am EST
Fascinating, Mark. Are they just attaching themselves for pupation or are they feeding off them?
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Entoman on Jan 11, 2015January 11th, 2015, 12:36 pm EST
Thanks, only noticed your link after posting my question. Oh, well...:)
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman