Back to the land of the Theliopsyche -- but no luck this morning

Having found a Theliopsyche Lepidostomatid (Bizarre Caddisfly) two weeks ago (see the entries for 12/19 and 12/21) which was not in the right case, I'm now determined to find one where it belongs ("Case: composed of sand grains, curved and slightly tapered" -- Beaty, "The Trichoptera of North Carolina," p. 81).  So this morning, the search was on in that small stream in Sugar Hollow: back to the scene of the crime.

I found two likely suspects: the one in the photo at the top of the page,

and this one.

That second case seemed to hold a whole lot of promise.  But alas, both larvae turned out to be genus Lepidostoma.  (For the difference between the genera, see the entry of 12/21.)  In fact that slightly curved case is being converted from a case made of sand to one made of "quadrate pieces of plant material" (Beaty, p. 81).

In time, it will probably look something like this.

_________________

Still, there were other nice insects to find.

1. A young flatheaded mayfly, Maccaffertium meririvulanum.  Tolerance value, a mere 0.5, but it's only found in these small, pristine mountain streams.  I picked up three or four in the leaves.

The key to identification is the "V's" on terga 5, and 7-9.  (Beaty, "The Ephemeroptera of North Carolina," p. 19)

2. And a young Northern case-maker, Pycnopsyche gentilis, the one that makes a three-sided case out of pieces of leaves and/or bark.

We see a lot of these small cases that are abandoned.  Apparently the larvae build new cases as they mature and out-grow the old ones.
________________

Back to the hunt when the weather warms up.  And there are other small streams to explore.

A rare one this morning: the "humpless case-maker" (Brachycentridae), Adicrophleps hitchcocki

I did not expect to see this this morning, and I didn't know what I had when I headed back to the car to start taking photos.  I was digging around in a very small stream/spring seep at high elevation in Sugar Hollow, sifting through gravel, hoping to find another Theliopsyche (see the posting for 12/21).  I picked up this case -- not even sure that it was a case -- until I saw a little brown head sticking out.

It was only when I looked through my camera that I knew what it was: the "humpless case-maker," Adicrophleps hitchcocki.  This is an insect that is listed as "imperiled" in the state of Virginia (http://eol.org/data_objects/28878539), but it's the second larva that we've found in Sugar Hollow's small headwater streams.  You may recall that my friend found one in December, 2013, and I posted an entry describing the find on 12/2.

Her photos were excellent -- and taken with a 65 mm lens (I use a 60 mm) -- and I encourage you to look again at that entry.  But to review...  since this larva hasn't been found in NC, we use the Wiggins book for our detail (Glenn B. Wiggins, Larvae of the North American Cadddisfly Genera, 1977 [1st edition], pp. 51-53).

1. There is only one Adicrophleps species -- hitchcocki.

2. To date, A. hitchcocki has only been found in Connecticut, Maryland, Pennsylvania, Virginia, and West Virginia.  (See Nature Serve Explorer.)

3. Wiggins keys out the genus in following way: "Each half of mesonotum subdivided into three separate sclerites, posterior margin not conspicuously raised or coloured." (p. 51)  (Note that the separation between sclerites 2 and 3 on each side is difficult to see, but they are distinguished by color.)

4. To this Wiggins adds, "The head of A. hitchcocki has light-coloured muscle scars and bears a pair of longitudinal ridges along the anterolateral margins of the frontoclypeal apotome." (p. 52)  Both features are clear in this close-up.

Actually, those ridges on the sides of the head are visible in one of my photos.

5. On the case -- "Larval cases in Adicrophleps are four-sided, tapered, and constructed of pieces of moss arranged transversely; trailing ends frequently left attached to the moss pieces give the case a furry appearance."  We can see that in all of our photos, and the transverse arrangement of the moss pieces shows up nicely in the photo that shows us the ridges.

6. I also noted in my post of 12/2/13, that in Wiggins' illustration of the larva on p. 53, it is clear that there are very long setae on the anterior edge of the pronotum.  No question about it.  (Also note the "divot" in the pronotum, a defining trait of the family.)

7.  One final point.  On the habitat -- "Larvae were collected in several cold, rapid streams from 1 to 10 m wide from aquatic moss in riffle areas at depths not exceeding 30 cm; they were exceeding difficult to find in the moss."  As I mentioned, I found this little larva (case was 6 mm long) in sand and gravel, and this was the stream.

_______________________

That was a treat... and what a nice way to start the new year!

An interesting morning at Buck Mt. Creek

I had hoped to get into the mountains today, but I didn't have time.  So, a quick trip to Buck Mt. Creek -- where the water is still running high.  I saw a lot of small winter stoneflies, but they're still not showing color (i.e. maturing) so I'll focus on other things.
__________________

Apatania incerta: common name, "little mountain case-makers".  I've only seen them in three different streams: Buck Mt. Creek, the Doyles River, and the Rapidan River.  Apataniidae, like Uenoidae, used to be considered a genus in the Limnephilidae family (northern case-makers), but is now a family all on its own.

This is the little larva that makes a "cornucopia-shaped" case with a hood at the top that completely covers the larva in the dorsal view,

though on occasion, you can see some or all of the legs.

Worth another look at Beaty's description.  ("The Trichoptera of North Carolina," p. 85)

Genus Diagnosis [for Apatania].  Mesonotum with two plates; metanotal sa1 sclerites absent; arrangement of sa1 associated setae in a linear transverse row.

Case: composed of mineral particles and strongly curved, cornucopia-shaped; larger mineral particles laterally.

A. incerta -- larvae 6-9 mm; head dark brown to black; nota brownish-black; anterior metanotal plates replaced by row of about 20 setae.

We can see the shape of the case in the photos at the top of the page.  For the "larger mineral particles laterally" -- i.e. a "flange" -- a couple of photos.

The color of the head -- "dark brown to black" -- can also be seen in our photos (also, legs are "yellow brown").  But for the nota, and the row of 20 setae that replaces the sa1 sclerites on the metanotum, best to use a microscope view.

We can actually count 10 setae on the left side of the metanotum.  This is, by the way, a fairly intolerant larva.  In the tolerance values assigned in North Carolina, the TV is 0.6.
_________________

Strophopteryx fasciata: one of our "large winter stoneflies".   The largest nymph I found today liked to sit on the A. incerta case!

Strophopteryx nymphs are given a tolerance value of 3.3.  I almost always find them in the very same streams in which I find the large winter stonefly, Taeniopteryx burksi/maura.   This is the best I could do for a photo,

but it's sure a good match for Beaty's description ("The Plecoptera of North Carolina," p. 7): "abdominal terga yellow with uneven, dark brown transverse bands on anterior half of each tergite; median row of transverse dark dots on each tergite."  Here's a close-up of those tergites, and also a look at the ventroapical plate the juts out from tergite 9.

You'll recall from the entry of 12/26, that the large winter stonefly T. atlanticum also has a ventroapical plate that is "broad apically" (Beaty, p. 7).  By way of contrast, those on Strophopteryx nymphs are "concave laterally" (Beaty, p. 6).  They look like this.

________________

Acroneuria lycorias.   And more evidence to support my theory that A. lycorias and A. carolinensis can be distinguished (see the entry posted on 12/17).

Once again, this nymph lacked medial longitudinal markings on the terga, but had anal gills.  On this one, the anal gills were gray, sparse, and hard to see.

A closer look at those gills.

A. carolinensis nymphs have medial markings and lack anal gills: A. lycorias nymphs are just the reverse.  By the way, I ran this by Steven Beaty, and he thinks this might work out to be true.  He finds the same correlation with the nymphs in his collection.  Aha!

Hope to celebrate the New Year in the morning by exploring a very small stream in Sugar Hollow.

Not a total waste anyway: a new Crane Fly larva, Dicranota sp.

I plan to do a lot of exploring this winter: new streams, new waters, and I hope some new insects.  That means getting into small streams higher up in the mountains.  This morning I tried a small stream that empties into the Doyles even though it wasn't all that remote.

Sort of struck out.  Oh, I found plenty of insects: large winter stoneflies (Taeniopteryx), some common stones (A. abnormis), some flatheads, one small minnow mayfly, and lots of Uenoids (all were the "tolerant" N. oligius).    The stream was in the woods at the top of a hill.  Still, there was a farm up above it, and the rocks -- and the insects as well -- were covered with silt.  Ugh!

One thing of interest: this little larva (10 mm), one I've not seen before.  From my live photos, it's easy to see the prolegs on the venter, but I needed a microscope photo to see if they were paired, and how many there were.

Five pairs on segments 3-7.

It took me awhile to find a Tipulidae (Crane Fly) with that exact number of prolegs, but there it was on pp. 776-777 of Merritt, Cummins and Berg (An Introduction to the Aquatic Insects of North America, 2008).

Paired prolegs (pseudopods) with sclerotized apical crochets (curved hooks) on venter of abdominal segments 3-7; larvae in wet to saturated soil along streams..... most Dicranota

As I recall, this one was in a pretty muddied up leaf pack.  However, if you look at some of the internet sources, you'll find that it's a fairly intolerant insect.  Tom Murray has posted a photo of one that was "netted from a fast flowing rocky mountain stream" (http://bugguide.net/node/view/264471/bgpage), and the North Carolina list of tolerance values gives a TV of 0.0 to Dicranota spp.  Maybe I need to see if I can get into this stream upstream from that farm!

From what I can tell, it's very difficult to key this one down to the level of species.

Large winter stones and Uenoids: reporting on two different streams

I've just returned from one of my small streams in Sugar Hollow where I found that winter is now in full swing.  Lots of small winter stoneflies, some Leuctrids (Needleflies), a few small Perlodids, oodles of Epeorus pleuralis flatheaded mayflies on the bottoms of rocks, and Giant stones (Pteronarcys proteus) that are getting fairly mature (they'll hatch in March and April).  And I found a large number of the large winter stonefly that we find in these small mountain streams -- Taenionema atlanticum (photo at the top of the page).   Beaty says they are "rarely collected" ("The Plecoptera of North Carolina," p. 7) -- a statement I've always found strange.  They abound in these small streams, and I find them as well in the Rapidan River.

In the photo at the top of the page, you can make out one of the key features for identification, the "ninth sternal plate [is] broad apically" (Beaty, p. 7).

This can be used to distinguish T. atlanticum from a similar large winter stonefly, Strophopteryx limata.  (Beaty, pp. 6 and 7)

And the Uenoids (Little northern case-makers) are starting to show up on the rocks.  Picked up two this morning, both were Neophylax consimilis.

(That young Free-living caddisfly larva that shows up in these photos is either R. glaberrima or R. invaria (Banksi complex).  Can't be sure which it was since I decided not to preserve it.  Both are fairly rare.)

Neophylax consimilis, you may recall is a Uenoid that has "ventral clavate gills" on abdominal segment 1, these...

but it does not have a tubercle on its head.  In some cases, the head/face is completely brown -- true of the nymphs that I found this morning -- in others there's an orange/red spot in the center.
_______________

That orange/red spot was very clear on this N. consimilis that I found last weekend in a trip to the upper reaches of Buck Mt. Creek.  (Click on the photo to enlarge.)

And there was another Uenoid up there, Neophylax oligius.

N. oligius, like N. consimilis, lacks a tubercle on its head, and it has ventral clavate gills.  But note the different marks on the face.  N. oligius has a long orange stripe on its face that extends from the top to the bottom.

And to end up where we began, Buck Mt. Creek was loaded with a quite different large winter stonefly: the large winter that we see in a lot of our streams, Taeniopteryx burksi/maura.

Pretty easy to recognize this one by the colors and that long, medial yellow stripe that runs the length of the body.  But if you want confirmation, flip it over.  There are long, telescoping gills at the base of each of the legs (coxal gills).

This is a fairly tolerant nymph with a tolerance value of 6.6.  (T. atlanticum has not been assigned a TV: too uncommon.)