This one's exciting, since this is a species that, until now, had only been found in Tennessee. It's a pronggilled mayfly (Leptophlebiidae), Paraleptophlebia kirchneri, and I found it in two different streams just a few weeks ago. As you can see, this nymph is fully mature: I also took photos of one that was not yet mature.
I was really excited to see this nymph again having found one on May 19, 2012, in Entry Run in Greene County.
It's clear that all of these nymphs are the same species by looking at the abdominal pattern, especially segments 7-10.
I was able to work out the ID using our new key published by Clemson University, John C. Morse, et.al., Larvae of the Southeastern USA: Mayfly, Stonefly, and Caddisfly Species. The relevant pages are 140-144. Let's work through the couplets.
First, it is clear that this is genus Paraleptophlebia since there is no tracheal branching on the gills, the branching we see on Neoleptophlebia nymphs, so we move to couplet 267.
267 Combined length of distal two maxillary palp segments about 1.5x or more length of proximal segment ...268
267' Combined length of distal two maxillary palp segments about 1.3x or less length of proximal segment ...273
This is a toughy. Here's what we we have to work with.
I measured this a couple of ways and came up with different numbers, reaching no certain conclusion, so I sent my nymphs to Steve Beaty, asking for help. He felt that segments 1 and 2 were about 1.5x longer than the proximal segment. So we move on to couplet 268. (Thanks Steve!)
268 Posterolateral projections present on abdominal segments 8 and 9 ... 269
268' Posterolateral projections present on abdominal segment 9 only ... 272
They were clearly present on both 8 and 9.
(In fact, on the nymph that was fully mature, they were present on segment 7 as well, but I forgot to take a picture!) We move on to couplet 269.
269 Legs with contrastingly dark area at femur-tibia joint; otherwise with only diffuse shading not forming distinct bands on femur and tibia ... 277
269' Legs not as above, with distinct dark banding, including for example, dark areas more centrally on femur and elsewhere on tibia and tarsus ... 270
It's pretty clear from my photos, I think, that there is not distinct banding on the legs, and yes indeed, there is a dark area at the femur-tibia joint. It's actually at the base of the tibia.
On we go to our final couplet, 277.
277 Abdominal sterna 2-8 or at least 6-7 with large, medial, orange spot in anterior half of segments; sternum 7 with additional, reddish spot posteriorly, sometimes coalescing with anterior spot ... Paraleptophlebia kirchneri
277' Abdominal sterna not exactly as above ... Paraleptophlebia ontario
Our key adds, on the orange spots, "Spots are best seen in fresh material." Well, my nymphs had been preserved so they weren't really "fresh," but I could see enough to make a determination.
The spots were there, even though faded. Two for sure on segment 7, anterior and posterior coalescing, and you can also make out faint spots on segments 5 and 6. This is a view of the spots on the immature nymph. On the mature nymph, they were more vivid, and present on segments 2-7 -- but I forgot to take a photo before I rushed that nymph off to Steve Beaty! Sheesh!
Fortunately, my good friend who lives on the stream where I found the mature nymph, had found this species in a previous year and had taken photos of the dorsal and ventral views. We have a fresh nymph! And check out those spots on the venter.
dorsal view -- with the same pattern on segments 7-10
ventral view
Gorgeous. Her photos really sealed the deal.
So, clearly, we have Paraleptophlebia kirchneri here in Virginia. In fact I've found it in three different streams: 1) Entry Run in Greene County, 2) a small branch of Ivy Creek in the Ivy Creek Natural Area here in Charlottesville, and 3) in a small, pristine stream that feeds into the Moormans River in Sugar Hollow at the base of the Blue Ridge Mountains.
I should note in conclusion, that this is the second species of Paraeptophlebia I've found that is not attested in the state of Virginia. The first was Paraleptophlebia strigula -- photo below -- a species I found in that same small stream in Sugar Hollow in 2017.
Unfortunately, neither species will be confirmed officially as being found in Virginia without an adult specimen. Alas!
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