And another new find: Ephemerellidae (Spiny Crawler Mayfly), Drunella lata

In early June, I went fishing in western Virginia -- Cow Pasture River -- and of course, I had to look for some insects.  Very happy to find this one, since I knew right away it was a Drunella nymph I had not seen before.  It turned out to be Drunella lata.

Drunella nymphs have robust fore femora with a jagged leading edge, something you can obviously see in this photo.  But what about the species?  Let's look at Steven Beaty's description ("The Ephemeroptera of North Carolina," p. 48). 

Nymphs 6-7 mm; head smooth with short, flattened lateral frontoclypeal projections which are about as long as wide; femora with few or no long, fine setae on posterior margin; abdomen without paired dorsal tubercles although diverging low ridges may be present on 3 or 4-8, becoming successively more parallel in posterior segments; dorsum brown with tergum 8 mostly pale; posterolateral projections on 4-8 and apices of femora pale; mature nymphs often with pale area tinged with red; ventral surface light brown.  Collected in February through July in the Mountains.

This nymph measured 7 mm. I didn't bother to take a close-up of the posterior margins of the femora, but certainly no setae are visible in the photos I've taken.  For the rest of the features, let's take them in order.

1) the smooth head, i.e. no tubercles on top like those we see in Drunella tuberculata (second photo below)

vs.

2) the short, flattened frontoclypeal projections, 

3) the diverging low ridges on sterna 4-8 (hard to see if they are progessively parallel?)

4) brown dorsum, with tergum 8 pale, and the pale apices of the femora and the pale areas on the femora which are tinged with red,

5) posterolateral projections on segments 4-8,

and 6), the ventral surface being light brown,

Pretty cool looking critter!  Drunella lata.

Oh, I also found a very pretty stonefly nymph, Agnetina flavescens.

Habrophlebiodes celeteria and americana: New pronggilled species

I have a number of blog entries lined up to post, so I thought I'd start with this one.  I found this nymph yesterday in my favorite small mountain stream and knew right away that it was the mature version of one that I found on July 7.  This one.

When I found this one on the 7th, I didn't know what it was, but I knew that it was a pronggilled nymph that I'd not seen before.  With the help of some of my friends -- Steve Beaty, Matt Green, and Donna Bennett -- I was able to determine the ID. 

At first, I thought it was genus Neoleptophlebia, seeing light tracheal branching in the gills,

but that turned out to be wrong.  New genus, Habrophlebiodes.  What I needed to see for that ID was  a deep notch in the labrum, a feature that was easy to see on a specimen my friend Donna found in the same stream a number of years ago.

Habrophlebiodes also requires posterolateral spines on terga 8 and 9: I've pointed those out in the photo above that shows the tracheal branching. 

What about the species ID?  For that I turned to the "Clemson key," Morse, McCafferty, Stark, and Jacobus, eds., Larvae of the Southeastern USA: Mayfly, Stonefly, and Caddisfly Species, 2017.  Habrophlebiodes species are keyed out on p. 138, and H. celeteria is clearly what we have.

"Head and mesonotum (dorsum of second thoracic segment) pale with some darker lines, pronotum and abdominal terga dusky yellowish, with abdominal terga paler at anterior margins and with pale mid-longitudinal stripe for length of dorsal abdomen; abdominal sterna 1-2 heavily pigmented and abdominal sterna 3-9 with pigmentation at posterolateral margins; mature body less than 4 mm."

The colors of the head, mesonotum, pronotum and abdominal terga are best seen in my specimen from July 7, and clearly they match the description.  The pale areas at the anterior margins of the terga and the mid-longitudinal stripe can be seen in the photos of both of my specimens posted above. 

For the markings of the abdominal sterna, they're best seen in a photo I took of my nymph from yesterday.

There is one other character trait for Habrophlebiodes that you can see on the specimen found by my friend.  There's a pale triangle at the front of the head. 

Cool!  Habrophlebiodes celeteria.
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On July 12, one week after my H. celeteria find, I went to another small mountain stream, Entry Run in Greene County, and lo and behold, I found another Habrophlebiodes nymph, a different species: Habrophlebiodes americana!

The pale triangle at the front of the head is clearly visible in the second photo above.  The branching on the gills, as well as the spines on terga 8 and 9, can be seen in the following photos. (Actually, there are spines on terga 7-10 in this species, as you can see in the photo.)

And this time, I managed to get my own photo of the notch in the labrum, clearly visible in this microscope shot.

But this did not look like H. celeteria, so what was the species?  Same page in the "Clemson key," p. 138. 

"Dorsum of head and body chestnut brown, without light mid-longitudinal stripe on abdomen."

Bingo! Habrophlebiodes americana.  
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In the past, I've only rarely gone to my small mountain streams, assuming that all of the good critters were gone: nothing to see until winter and spring.  Have to change my thinking on that one!

Here are a few more photos of the H. celeteria nymph that I found yesterday, shots from different angles. 

A New Pronggilled Mayfly: Paraleptophlebia kirchneri

It's been awhile since I've posted an entry, but as you know, I'm reserving this format for new finds.  Remember that I post photos daily on Instagram (buddhabob2hanlubo).

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.

 (I misidentified this nymph as P. debilis in a post of 6/29/17, and as P. jeanae on 7/1/17!)

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!

Leptophlebia: Working on the species ID of a nymph I found on New Years Day

I celebrated New Years Day by going to a tiny, slow water stream in Sugar Hollow and was rewarded by finding a pronggilled mayfly nymph, genus Leptophlebia.  This is only the second time I've found a nymph of this genus,  the first was in December of 2012.  This one.

We can ID these nymphs to the level of genus by looking closely at the gills. 

Gills on segments 2-7 on Leptophlebia nymphs are bilaminate, meaning they have two leaves on each gill, each one ending in a thin, string-like filament.  Here's a microscope view.

Having not saved the nymph I found in 2012, I was excited to find this nymph so I could work out the species ID, though admittedly, the one I found on Wednesday might not be the same species as the one I found 2012.

So what did I find?  My findings suggest that this is either L. cupida or L. nebulosa (the two species  cannot be safely distinguished as nymphs).  However, the two keys that I use both describe features for this ID that I can't be sure that I see: my microscope doesn't provide the magnification that I need.  More on that as we proceed.  Here are the information I've found. 

1. Larvae of the Southeastern USA: Mayfly, Stonefly, and Caddisfly Species (Clemson University, 2017), pp. 138-139).  The couplets are these.

259  Abdominal terga with numerous spinelike setae on lateral margins ........260
259' Abdominal terga with very few or no spinelike setae on lateral margins..........262

Let's look at our nymph.

There are indeed, numerous spinelike setae present.  On to couplets 260 and 260'.

260  Forelegs with broad tibial and tarsal banding as in Fig. 2.423; inner margin of forefemur with considerable palmate setae (Fig. 2.424) ....Leptophlebia intermedia
260' Forelegs without broad tibial and tarsal banding (if banding present, then much narrower or much fainter); inner margin of forefemur with numerous serrate setae with small serrations on one or both sides of setae (Fig. 2.425) .......... 261

Look at the tibia and tarsus.

There is a dark area medially on the tibia, but it is clearly not a band, and there is banding at both ends of the tarsus, but it's clearly narrow and faint.  On the setae on the forefemora, the magnification of my microscope is not strong enough to let me determine the shape of that setae (though I can see it).  But since there is at the most faint banding of the tibia and tarsus, I'd conclude that we should move on to couplet 261/261'.

261  Labrum typically with dorsal surface setae as in Fig. 2.426 .............Leptophlebia cupida
261' Labrum typically with dorsal surface setae as in Fig. 2.427 ............. Leptophelbia nebulosa

The figures in question (on p. 139) both show setae covering the labrum, but the illustration for L. nebulosa has a dense area of setae in the upper half of the labrum, an area that is missing on the  L. cupida nymph.  While I am able to see the setae covering the labrum, I cannot determine if that dense area of setae is present or absent.  Moreover, our key adds the following note: "It may not always be possible to differentiate the larvae of L. cupida and L. nebulosa.  Rearing to obtain  the more easily differentiated adults is advisable." 

If my logic is correct, our nymph appears to be either L. cupida or L. nebulosa, but that's as far as we can go.   Having reached that conclusion, I decided to see what Steven Beaty had to say.

2. Steven Beaty, "The Ephemeroptera of North Carolina," p. 78.  Here are his descriptions.

cupida -- nymphs 8.9-13.2 mm; peg-like setae on palpifer (small basal segment of maxillary palp) usually in regular rows; many large spine-like setae along lateral margins of abdominal segments along with scattered long hair-like setae; legs not usually banded or with faint bands on tibiae and tarsi only.  Note: need to slide mount mouthparts and legs to separate from L. nebulosa which still may not guarantee correct species identification.

nebulosa -- nymphs 7.1-12.5 mm; peg-like setae on palpifer (small basal segment of maxillary palp) usually in regular rows; many large spine-like setae along lateral margins of abdominal segments along with scattered long hair-like setae; legs usually faintly banded or with faint bands only on femora with more distinct bands on tibiae and tarsi.  Note: need to slide mount mouthparts and legs to separate from L. cupida which still may not guarantee correct species identification.  

This is tough.  We've already seen that there are "large spine-like setae along [the] lateral margins of the abdominal segments along with scattered long hair-like setae".  All well and good.  On the legs, there does appear to be faint banding on the femur, though it isn't complete, and I can't say that the banding on the tarsus and tibia is any more distinct.  For the "peg-like setae on the palpifer," I think I can see it, but once again my microscope magnification won't allow me to confirm that let alone try to take a clear photo (I tried!). 

Kind of stuck.  I do think it's safe to conclude that our nymph is either cupida or nebulosa, but there's no way to go beyond that without a microscope with greater magnification.  And even with that, we probably need an adult to be certain of our ID. 
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One other thing about this nymph. 

Check out those eyes.

This "double eye" feature is something we also see on occasion on Baetidae nymphs, and it indicates that this is a male.  The brown eyes on the sides are "compound eyes" that allow the nymph to see in various angles, the red eyes in the middle are "tubinate eyes" and are used by the adult mayfly to see directly above itself.  They allow the male to pick out the females during mating.  Very useful!
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My photos can now be found on Instagram.  My IG name is "buddhabob2hanlubo".  I'll only be using this blog to post info on the new species I find, working out the species ID.