A significant find in Sugar Hollow: The case-maker Pseudostenophylax sparsus

I can't take credit for this one.  This caddisfly larva was found on Sunday by my friend who lives in Sugar Hollow in a spring seep on her land: all of the photos are hers.  It's a new taxon to add to our EPT list, something that's "rare," and from what I can tell it has not been found before this in the state of Virginia (see: http://eol.org/data_objects/14881240).  It is listed as "vulnerable" in North Carolina.

Limnephilidae (Northern case-maker), Pseudostenophylax sparsus.  This is a species that, according to Beaty, "occurs in seeps and temporary streams" ("The Trichoptera of North Carolina," p. 84).  According to Wiggins, "the larvae live in cool spring runs or small streams of intermittent flow; they burrow into sand and gravel substrate as water recedes and presumably are protected there until the return of surface water." (Larvae of the North American Caddisfly Genera, First Edition, 1977, p.278.)   This one was found, quoting my friend, in a "little spring that emerges from an iron pipe in the ravine near our upper garden."  She adds that "this pipe comes out of a wall (constructed of cement blocks more than 100 years ago), feeds into small spring pool (in photo below).  Water flows from it after heavy or prolonged rainfall.  Thus it may be dry for more than 1/2 of the year."

 The case was ~ 20 mm and was made, as you can see, out of pebbles and sand.  On the case Beaty says: "composed of sand, curved and slightly tapered." (p. 84)  That's just what she found.

For the genus ID, let's go to Beaty.  "Mesonotum with pair of plates with as (sic.) [all] setal areas confluent; row of metanotal setae between sa2 and sa3; lateral humps without sclerites; abdominal gills single; head and thorax uniformly orangish to yellowish brown with pale muscle scars." (p. 84)  (Wiggins, p. 278, says much the same thing.)

1. The color of the head and pronotum and the pale muscle scars are clear in the photo above.

2. The "confluent setal areas" (i.e. setae run from sa1 to sa2 to sa3) show up pretty well in this photo.

3. And the metanotal setal row between the sa2 sclerites is very clear here.

3. The left lateral hump can be seen in the following photo, though it is difficult in this shot to see if there may or may not be any sclerites.

4. On the abdominal gills -- they are single, but we don't have a photo.  This insect was not preserved: it was returned to the spring.  But my friend had a clear view of the gills when the larva crawled far enough out of its case.  It just didn't stay out long enough to get a picture.

I don't see any reason to doubt this identification, and it is, indeed, a significant find.  I normally skip over spring seeps when I'm out looking for insects, but that's about to change.
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When Wiggins was writing in 1977, two species of Pseudostenophylax were said to exist in the Eastern U.S. -- P. uniformis and P. sparsus (p. 278).  But according to Beaty (p. 84) "Pseudostenophylax uniformis is now considered a subspecies of P. sparsus."  In some sources, by the way, it is called Pseudosteonophylax sparsus uniformis.
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Late addition: While sorting through the vials in my own Limnephilid collection, I found one marked "Pseudostenophylax":  it contains two larvae I had collected in spring 2010 in the "bio-blitz" at Patricia Byrom Park.  P. sparsus for sure!  Here are two microscope photos: 1) the single gills on the abdominal segments, and 2) another look at the setal rows on the meso and metanota.

Taihao le 太好了 the Chinese would say.  "Too much!"
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Late correction: P. sparsus was reported from Giles, Greene, Madison, Page, and Rappahannock counties in 2008 by Flint.  "In Virginia it has been taken mostly in the northern Blue Ridge in and near Shenandoah National Park." Oliver S. Flint, Jr., Richard L. Hoffman, Charles R. Parker, "An Annotated List of the Caddisflies (Trichoptera) of Virginia: Part II. Families of Integripalpia," Banisteria, Number 31 (2008), p. 16.

Another look: that free-living caddisfly larva was probably R. glaberrima

Back we go to this free-living caddisfly larva from Entry Run.  On Sunday (3/9) I suggested that it might be Rhyacophila shenandoahensis.  But Steven Beaty, based on the photos I sent him, said that R. glaberrima was a more likely ID.

On R. glaberrima, Beaty has only a little to say: "larva 12/ ?? mm; both apicolateral spur and basoventral hook absent; length of segment 2 of maxillary palpi subequal to segment 1. Relatively rare... Collected during spring and summer in the Mountains and Piedmont." ("The Trichoptera of North Carolina," p. 61)

All of that's true of our larva, but can we find a more detailed description?  Fortunately, one is provided by Flint ("Larvae of the caddis fly genus Rhyacophila in eastern North America," p. 471-473.)

Description: Length, 12 mm.  Head, brownish yellow, slightly darker centrally; muscle scars paler, inconspicuous. ... Thorax, pronotum brownish yellow, darker centrally; muscle scars dark; fore femora very broad.  Abdomen, anal proleg with neither basal hook nor apical spur ... claw with 2 ventral teeth. (p. 472)

While the fore femora does not show up very well in my photos, it is indeed very broad.  And the rest of Flint's description is right on the money.  Note the colors of the head and pronotum.

And we've already seen the lack of the basoventral hook and the presence of two ventral teeth.  The apicolateral spurs would -- if they were present -- stick out to the sides of the anal claws.

(Note: There are also two ventral teeth on Rhyacophilids -- like R. shenandoahensis -- in the R. banksi complex of the R. invaria group.  But, on those larvae, the second tooth is very small; not so here.)

There is one other trait of R. glaberrima that is clear in our photos.  There is an oblique suture on the baso-lateral sclerite, a black line.  This feature is illustrated by Flint on p. 471, and it's very clear in this photo.

So, the evidence suggests a correction in our ID.  That Rhyacophilid was R. glaberrima, not R. shenandoahensis.

Microscope photography: taking close-ups of anatomical features

(Microscope photo of the ventral teeth on the anal claws of a free-living caddisfly larva.)

One of our readers has asked what sort of set-up I use for my diagnostic microscope photos.  Since others might like to play at this business as well, here's how I do it.  One caveat at the very beginning: there are many, many ways to take microscope photos.  I doubt that my way is the best -- but it's good enough for me.  (But I'm happy to entertain suggestions on how to improve.)

1. My microscope is an Omano 2300S-V3 Zoom Stereo.  My magnification range is 7X -- 45X.  The round black plate on the base of the scope can be flipped over to a white side.  I often try both sides to see which works the best.  My specimens are in a petri dish filled with alcohol.

2. Forget the ring light they send you with the scope.  You need "Goose-neck" lights to get decent lighting.  I use AmScope LED lights, which are relatively inexpensive, but there are lots of units from which you can choose.

3. To attach your camera to the microscope you need two different things: 1) a "ring adapter," which is camera type specific (e.g. Canon, Nikon), and 2) an eye-piece adapter.  Make sure that your eye-piece adapter is the same diameter as your microscope eye-piece.

4. One end of the eye-piece adapter is threaded and screws on to the ring adapter, the other end fits over the eyepiece on your scope.

5. The ring adapter then fits on to your camera body just like a lens.  I.e. you line up the red or white dots on the two units, fit together and twist (that's the way it works with my Canon, at least).  So, YOU WILL NOT BE USING ANY LENS ON YOUR CAMERA: the microscope objective BECOMES your camera lens.

6. Slip the eyepiece adapter over the eyepiece on the scope and tighten to secure.

7. You're good to go.  To focus your shot, use the focus knob on your microscope, and to get the right light, adjust the shutter speed on your camera.  I usually work between 1/20th second to 1/4th second -- but sometimes I go slower and sometimes I go faster.

Good luck.

On that free-living caddisfly larva -- could it be Rhyacophila shenandoahensis?

The Rhyacophilid I found yesterday at Entry Run in Greene County -- the one in this photo -- might be Rhyacophila shenandoahensis.  Should that turn out to be true, this would be quite a find.

R. shenandoahensis appears to belong to the R. banksi complex of the R. invaria group -- on which see the entry posted on 1/28/14.   Like other members of that complex, our larva does not have an apicolateral spur, lacks a basoventral hook, and has two ventral teeth on each anal claw.

R. shenandoahensis was described by Oliver S. Flint, Jr. in his article, "Larvae of the caddis fly genus Rhyacophila in Eastern North America,"  Proceedings of the United States National Museum, 113:3464 (1962), pp. 483-484.   Before I read parts of that description, have a close look at the head of our larva.

Flint.  "This species has been collected only in the mountains of Shenandoah National Park and those nearby."  (Sure helps our case.)  "Description: Length, 16 mm.  Head, brownish yellow, marked with deep brown, both mesodorsally and ventrally; muscle scars pale, inconspicuous, head capsule slightly wider posteriorly, apex of frontoclypeus blunt."  (I don't have a photo of the ventral side of the head; the rest seems to fit.)  "Thorax, pronotum, yellow, with dark oval mark posteromesally [i.e. back middle]; fore femora much broadened.  Abdomen, anal proleg with short basoventral and apicolateral processes, not free of membrane [i.e., neither sticks out]; claw with a second small ventral tooth."

I think the head and pronotum of our larva match the description supplied.

and

In his remarks, Flint reiterates the close connection of this species with the SNP.  "The larvae of this species seem to be the only ones of the genus in the small brooks and springs of the Shenandoah National Park."  Some of the places where this species is found: Hogcamp Brook (not far from Entry Run), Skyline Drive, Milepost 71.5, Skyline Drive, Milepost 79.5, even near Waynesboro.  We're right in its domain.

However, two points made by Flint work against this ID for our larva.  1) "The larvae were not collected in brooklets more than a yard wide, and were often found in the leaf packets in the small springs."  I did indeed find this larva in a leaf pack, but Entry Run where I was looking was certainly wider than a yard.

2) "Although the larvae were not collected in the fall, they probably do hatch before winter, inasmuch as the larvae are nearly full grown by early March."   The larva I found was far from being "full grown"; it was only 8-10 mm.
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So, we can't be sure we found R. shenandoahensis  -- but it's still an ID to consider.  Since even the pros can't really distinguish the species in the R. banksi complex from one another, this is the best we can do.   It's nice to live near these mountains where the Rhyacophilids abound!

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(Oh.  R. shenandoahensis has been found in Canada (Ontario) and Virginia.  In Virginia it's listed as "vulnerable."  See: http://eol.org/data_objects/14885930.)

Don't mess with the Rhyacophilids (free-living caddisfly larva)! Moving up Entry Run

That flatheaded mayfly just got a little too close!  Rhyacophilids are predaceous.  Had I not broken this up, that flathead would have been missing a leg.

Close call!  This free-living caddis is one that we see fairly often in small mountain streams: Rhyacophila nigrita.  The dark front edge of the pronotum is a fairly good clue.  This was a big one -- ~20 mm -- and chubby as well, and it was one of three species of Rhyacophila I saw today at Entry Run.  The other two: R. fuscula (the green one with the topless "H" on the head), and Rhyacophila sp.  This one.

No guess yet on the species ID: I'll need some time.  It may be one we've not seen before.
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As for the flatheaded mayfly in that photo at the top of the page, it belongs to the "group" Epeorus pleuralis, but the species is Epeorus fragilis.  For the distinction, Look back to my posting of 5/26/13.   Here's a better look at our mayfly.

And this is Epeorus pleuralis.

The difference is in the head.  With Epeorus fragilis, the edge/margin of the head separates abruptly from the eye, and there's a distinct anteromedial "V".  The posterolateral margin of the head is essentially covered by the eye.

By contrast, on Epeorus pleuralis, the posterolateral margin of the head is exposed.

As you know, Epeorus pleuralis is common right now in all of our good mountain streams, with nymphs covering the bottoms of rocks.    Why Epeorus fragilis shows up as well in this particular watershed -- Entry Run/South River -- is something I need to explore.
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I was investigating new water this morning: I drove up Entry Run Rd. as far as I could go making a good jump in elevation.  The water was small and crystal clear.

I photographed quite a few insects, but the photos just didn't turn out.  One of those days.  But you can be sure I'll return later on in the spring.
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Can we say goodbye to winter? A mature S. fasciata large winter stonefly at the Doyles

Sorry.  This is not the S. fasciata large winter, but it has to come first.  A beautiful Perlodid stonefly Helopicus subvarians.  It was about the same size as the one I found last week at Buck Mt. Creek: 17 mm (about 3/4 inch).  I do believe that H. subvarians is the largest Perlodid stonefly I see.

Gorgeous!  This is still immature; the wing pads will lengthen, spread out from the body and turn black.  I normally find nymphs that are fully mature in late March and April.  The photo below was taken on 4/8/12.

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I don't know anyone in Virginia who does not want to wish this winter "Goodbye."   Cold, cloudy, rain and snow.  But there are signs that things are starting to change, both outside and in the insects we see in our streams.  The winter stoneflies -- the small winter stonefly Allocapnia pygmaea, and the large winter stoneflies, Taeniopteryx burksi/maura, Taenionema atlanticum, and Strophopteryx fasciata -- are just about gone.  The small winters are the first to go, then T. burksi/maura followed by Taenionema and Strophopteryx.  Here's the S. fasciata that I found today.

Fully mature.  But from earlier in the winter...

Small winter, Allocapnia pygmaea: 12/11/13

Large winter, Taeniopteryx burksi/maura: 1/19/14

And in Sugar Hollow last week (3/1), I found a Taenionema atlanticum nymph that looked exactly like this (though this photo was taken on 2/2/12).  The Malirekus hastatus nymph ate it when I wasn't looking!

If the winter stoneflies take winter with them, I can't say I'm sorry to see them go!
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But there were also clear signs of spring at the Doyles River this morning.

1. Small minnow mayfly, Heterocloeon amplum, one that's starting to show its colors (note the orange color of terga 4 and 5).

This one was clearly a male -- note the large eyes.  Also worth noting -- and I've seen this before -- the eyes at this point appear to be "double" as they transition to red.

2. A "tiny" spiny crawler, Ephemerella invaria, the one with the tubercles on abdominal segments 3-8.  (Too small to see in this photo; it requires magnification.)

3. And a small Isoperla montana/sp., the Perlodid stonefly that we saw in great numbers at the Rapidan River just a few weeks ago.

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But nothing could compare to this beauty.