It's the most colorful spiny crawler we see -- and at 8.5-9.5 mm -- one of the largest, and the only place that I've seen it is the Rapidan River up in Madison County: Ephemerella subvaria. Beaty says that it's "collected summer through fall"..."mountains only"... and that it's "rare." ("The Ephemeroptera of North Carolina," p. 28.) I see them in fall through winter, and this is about as small as they get.
This one was collected last year on September 22:
This one on December 6:
And these -- male and female -- on March 29:
I'm glad that the season has started, and I look forward to seeing them more and more on future trips.
With this "tiny spiny" as the exception, the insects I saw today were much the same insects I saw on my last trip: Giant stoneflies, Common stoneflies, Humpless casemaker caddis, some flatheads, common netspinners, and fingernets. Oh, and the occasional small minnow mayfly -- looked to be B. intercalaris.
1. Giant stonefly, Pteronarcys biloba. Getting bigger and bigger.
2. Giant stonefly, Pteronarcys proteus.
3. Common stonefly, Acroneuria abnormis. (Note how different this is from the one that I found yesterday in the Rivanna.)
4. And one of the many Brachycentrids (humpless casemaker caddisflies) that I saw clinging to rocks. Brachycentrus appalachia.