Always exciting to find something new, especially when it's something that has not yet been attested in the state of Virginia.
Pronggilled mayfly, Paraleptophlebia strigula. Donald Chandler of the University of New Hampshire has shared with me his Leptophlebiidae Key for New England and here's how that works.
3. Trachea of gills with lateral branches 4
Trachea of gills without lateral branches 6
Our nymph lacks tracheal branches
6. Segments of maxillary palpus all elongate, each at least 4X as long as wide, together about twice as long as maxilla 7
Segments of maxillary palpus comparatively short, less than 3X as wide as long, together only slightly longer than maxilla 9
Using photos I printed out to get an accurate read of the ratios, it is clear that we move on to "7"
7. Posterolateral angles of abdominal segments with gills bearing a black streak along margin; known from CT and ME; length 8 mm Paraleptophlebia strigula
The black streaks are clear in my photos. My nymph only measured 6 mm -- but it was still immature. I'll look for something more mature later on in the summer.
And let's not forget the posterolateral projection on segment 9, absent on 8.
I'd say the identity is confirmed.
NatureServe Explorer says this species is attested in the following states: CT, IN, KS, MA, ME, MI, OH, and PA. Seems to me that VA can be added to the list. Also worth noting, although Beaty does not mention P. strigula as a species that occurs in NC, there is evidence that it very well might. Don Kirk, in his book Hatches & Fly Patterns of the Great Smoky Mountains (p. 59) lists Paraleptophlebia strigula as one of the Blue Quills that is found in the national park. That leaves TN, NC, and GA as possible locations as well.
All of a sudden, pronggilled mayflies become interesting (: And don't forget that there are two other genera that we can explore.
Habrophlebia (vibrans), and
Time to start paying attention.