New caddis casemakers from my trip to Montana

It was a very good trip.  Fishing was great -- so too was the insect collecting.  In this entry, two caddisfly casemakers that I've not seen before: next entry, two new flatheaded mayflies.

Number one, this neat larva with a prominent dorsal hump and long stringy gills.  Found this one in a backwater eddy of the Bitterroot River, kind of like this one.

The water was still, relatively shallow (1-2'), with a sandy bottom.  There were about a dozen of these crawling along on the sand.

This identification has given me fits.  I got it into my mind -- given that prominent hump and the long, single gills -- that it had to be Phryganeidae (Giant Casemaker).  That led me astray for most of yesterday.  That just didn't work, so I keyed it out and came out to Limnephilidae, Northern Casemaker.   One of the things that led me in that direction was the fact that the mesonotum has sclerotized plates while the metanotum is largely membranous with sclerites at sa1, sa2, and sa3.

That led me to Wiggins (Larvae of the North American Caddisfly Genera, 1977), where I worked through the descriptions and illustrations of the various genera of Limnephilidae.  Even then, the genus ID wasn't real clear.  But in the end, I've decided that the probable genus ID is Psychoglypha (Wiggins, p. 280-281).  Here's Wiggins' description:

Larvae of Psychoglypha spp. are sufficiently divergent morphologically that it is difficult to find characters diagnostic for the genus.  The two sclerites lying close to the dorsal edge of the lateral hump of abdominal segment I provide the only consistent character discovered thus far for all the larvae we have collected.

I can see such sclerites on the larva I found, and, they are the same shape and size that we see in Wiggins' illustration (p. 281).

A few other features.

...in a few species stout spines and setae occur along the pronotum and on the sclerite of segment IX and the lateral sclerites of the anal prolegs.

The spines and the setae on the pronotum seem to me to be present on this particular larva, and the stout setae on the sclerites on segment IX and the anal prolegs clearly have "stout spines and setae."

Head markings usually consist of dark brown spots and blotches on a yellowish brown background, except in P. bella where the head and legs are uniform dark brown.  Abdominal gills are single.  Length of larva up to 26 mm.  

The gills are single for sure (not branched).  The head color -- I see a dark brown head and legs, but P. bella is a species that has not yet been found in MT.  (But it is listed in Rohrbeck in his record of Psychoglypha species. ???)  The Psychoglypha species that have been found in Montana are alascensis, prita, and subborealis.  (See Natureserve Explorer, explorer.natureserve.org).  This larva was only 16 mm, and the case was 29mm.   But I think this larva was still immature.   For the habitat, Wiggins says this: "Psychoglypha larvae occur in a wide range of cool-water habitats, ranging from springs runs to larger streams and their marginal pools."  I can live with a "marginal pool" for this one.  In any event, at this point, Psychoglypha is my best guess for the genus ID.   I might know more if I can get Steve Beaty to have a look at this larva.

More photos.

_________________

Number two, a Uenoid.

I found these Uenoids in a small mountain stream that's across the street from the motel we use: Grant Creek.   There were a bunch of them attached to the rocks near the shoreline.

All Uenoids are genus Neophylax, but what about the species ID?  For a number of reasons, I think it's N. splendens.  Let's go over the data.   To begin with, the source I use to work on genus and species ID for the insects I find in Montana is Roger Rohrbeck's Fly Fishing Entomology, here using the descriptions found in the section "Pacific Northwest Caddisflies" (http://www.flyfishingentomology.com/PNW%20Caddisflies.htm).   There are three species of Neophylax described at this site: occidentis, rickeri, and splendens.  I think we can eliminate N. occidentis.  The pronotum of the species is described as "front 1/3 light, rear 2/3 dark," and "evenly spaced spines at front edge with only a few scattered hairs on rest of pronotum."  Don't see that at all on our larva.  There are quite a few, very small, hairs on the surface of the pronotum, and the front 1/3 is actually darker than the rear.

That brings us to rickeri and splendens.  There are a couple of things that lead me to an N. splendens ID.  First of all, on rickeri, there are "short stout black setae scattered evenly across entire surface of [the] pronotum," while on splendens there are "fewer dark thick setae concentrated towards back."  Have a look.

I'd say there are thick dark setae at the back of the pronotum, with smaller setae mainly along the inner edges of the pronotal plates.

Secondly, Rohrbeck notes that "there are prominent gill-like filaments on the underside of ab1."  That means clavate gills on the venter.

And there they are.  But there is more.  The key source to use on Neophylax species ID is the book The Caddisfly Genus Neophylax (Royal Ontario Museum, 2005), edited by R.N. Vineyard, G.B. Wiggins, H.E. Frania, and P.W. Schefter.  There it is clear that rickeri and splendens are similar in many ways (e.g., dark heads and legs).  But on rickeri they note that the spines on the leading edge of the pronotum are "moderate in size" while those on splendens are "small".  I'd go with small.

Also a critical factor, rickeri is said to inhabit "medium to large streams" while splendens "occurs in small first-to third- order streams.  Grant Creek is, without question, one of the latter.  You might recall the photo I posted in April.

So I'd lean towards N. splendens for the ID.  But as always, I could be wrong, and rickeri can't be ruled out without closer inspection than I can do.
_________________

Good fun as always, and going to Montana in July instead of August -- when we normally do -- means finding a new set of insects.  In the next entry, a look at a new Epeorus and a new Leucrocuta.

We may have found a new Northern Case maker: Pycnopsyche luculenta

On Saturday, as I looked through my reference vials, I discovered a pair of Limnephilids (Northern Case makers) that I had found years ago in the Whippoorwill Branch of the Mechums (one was in the case in the photo above).  I had identified them to the level of genus -- Pycnopsyche -- but not to the level of species.  Decided to give it a try.  I concluded that they were P. scabripennis, but I thought I'd check in with Beaty.  Without seeing the larva, he said that the case looked like that of P. luculenta.  Well, back to the drawing board.

I began by looking at Beaty's description of P. luculenta.  ("The Trichoptera of North Carolina," p. 85)

P. luculenta -- larvae 20-22 mm; head yellowish, dark spots mostly distinct, ventral margin of posterior femora with 3-4 major setae; venter of first abdominal segment with more than 15 setae.  Case a distinctive, slightly flattened cylinder of plant materials with long sticks laterally extending posteriorly.  Common.

Kind of a perfect description of the case.  But let's look at the larva.

1. Pycnopsyche -- single abdominal gills.

2. Pycnopsyche -- long sclerite at base of posterior of lateral hump.

3. Pycnopsyche -- metanotal sa1 sclerites not fused.

Good to go on the genus.  On to the species ID.

1. Size of the larva?  Mine was 20 mm so that fits.

2. Head color and pattern look right.

3.Ventral margin of the posterior femora -- are there 3-4 major setae?  I'd say that there are.

4. The case we've already cleared.  But what about the setae on the first abdominal ventral segment?  I see a total of, maybe 10 setae, and most are very small.

Now that looks like a problem.  There clearly are not more than 15 setae on the first ventral abdominal sternum.  However, when Steve wrote to me yesterday, he sent me a new key on Pycnopsyche, part of a new book that has just been released: John C. Morse, W. Patrick McCafferty, Bill P. Stark, and Luke M. Jacobus, Editors, Larvae of the Southeastern USA: Mayfly, Stonefly, and Caddisfly Species (Clemson University Press).  (I immediately put in my order!)  Let's see what we get using that key.

230.  .... case cylindrical, constructed of stones only........231
230'; .... case cylindrical or depressed, constructed of plant materials or of sand, or stones and often with plant materials..........232

We move on to 232.

232.  Ventral margin of each hind femur with 3 or more major setae.... 233
232'.  Ventral margin of each hind femur usually with 2 major setae.... 234

We've already seen that there are 3 or more major setae on the hind femur.  On to 233.

233. Abdominal sternum I with 12-17 anterior (sa1) setae (mostly very small), 6-7 setae on each posteromesal (sa2) sclerite, and 6-8 setae on each lateral (sa3) sclerite....Pycnopsyche divergens

233'  Abdominal sternum I with 3-11 anterior (sa1) setae (mostly very small), 3-6 setae on each posteromesal (sa2) sclerite, and 2-6 setae on each lateral (sa3) sclerite; case depressed in cross section and with 1 or more long sticks along sides...........streams........... WI to QC south to AL, GA, KY, MS, NC, SC, TN, Pycnopsyche luculenta

The case is a match for P. luculenta.  So too is the number of setae on abdominal sternum I.  What about the number of setae at positions sa2 and sa3?  Two microscope photos.

No problem on the sa2 sclerites: I see 4 on each.  How about sa3?

I can see 2, possibly 3, setae on the lower lateral sclerite.  Have to say that if we use the new key, we key out, indeed, to Pycnopsyche luculenta.  I'll send these larvae to Beaty in a couple of weeks -- when I return from Montana (:  to see what he thinks.  But I feel pretty good about that ID.

One more thing, I have pics of another larva I found in another small stream in Sugar Hollow that also looks like P. luculenta to me.  Very cool.

_________________

While I was working on this yesterday, I decided to use the new key to see what I could find out about the many Limnephilids I've found over the years at the Rapidan River.  Here are pics of a few.

I could go on.  I seem to find 1 or 2 every year.   Using Beaty's description ("The Trichoptera of North Carolina," p. 85), I had concluded, with reservations, that these were all Pycnopsyche scabripennis.  I say reservations because he says that there are less than 15 setae on the "venter of [the] first abdominal segment":  I always see more.   (More than 20, by the way, would lead to an ID of P. guttifer, but that's problematic.  P. guttifer is said to be found in "large, warm streams": that doesn't describe the Rapidan River at all.)

Let's use the new key.  As we did before, we can move to 232 from item 230.

232.  Ventral margin of each hind femur with 3 or more major setae.... 233
232'.  Ventral margin of each hind femur usually with 2 major setae.... 234

Let's see what we've got.  (I'm using the larva in the last photo above.)

In this case I'd say there are no more than 2 major setae on the femur.  On to item 234.

234.  Case mostly mineral; in .....lowland streams.. or possibly spring brooks... or lakes and streams  (that's clearly out)
234'  Case of plant material; in 
...... small to moderate streams
.....  or small to medium rivers (that includes P. guttifera)
.....  or larger streams & rivers
.....  or possibly spring brooks
....   or cool, moderate-size streams ..... Pycnopsyche scabripennis
....   or lowland streams

The Rapidan River is, without a doubt, a "cool, moderate-size stream."

Think my previous ID can stand.  Can't wait to get that new book!
_________________

As noted above, I'm off to Montana for a week of fishing and insect collecting.  Next entry will be a report on those findings.

______________

Should note, by the way, that I'm not sure that all of the Rapidan Limnephilids I've found were P. scabripennis.  I have found some with cases that look a lot like P. luculenta.  Unfortunately, I can't check them since I no longer have the larvae.

But I forgot about Paraleptophlebia jeanae

My post of two days ago was premature.  I had forgotten all about the article I read just two weeks ago(!), written by R.P Randolph and W.P. McCafferty: "First Larval Descriptions of Two Species of Paraleptophlebia (Ephemeroptera: Leptophlebiidae)", Entomological News 107 (4) 225-229, 1996.  The two species described are Paraleptophlebia assimilis and Paraleptophlebia jeanae.  In the article, the authors note: "In present keys to the larvae of Paraleptophlebia, P. jeanae will key with P. debilis (Walker) at couplet 9 of Traver (1935: 515) and couplet 7 of Burks (1953: 90).  This is because of the similarity of gill structure, posterolateral projections on abdominal segments 8 and 9, and brown banding on the legs of P. jeanae and P. debilis."

Their description of P. jeanae goes into detail on 1) the parts of the head (head capsule, eyes and antennae, labrum, mandibles, maxillary palps, hypopharnyx, etc.); 2) the markings on the thorax and legs; and 3) abdominal coloration.  Of all of these features, most important of all is the mouthpart structure. ("Although abdominal coloration may prove to be unreliable to differentiate the larvae of these two species [i.e. debilis and jeanae], mouthpart structure will consistently distinguish them.")  Of course, that's the one thing I cannot examine without a specimen or two, something I won't collect until next winter or spring.  Bummer.

What I can see is the abdominal coloration, and that is very interesting.  Let me review what they say.

Abdominal coloration variable: abdominal tergum 1 brown; terga 2-9 often with paired crescent-shaped pale markings submedially on each tergum; submedial tergal markings less often coalescing, forming larger pale area in posterior area of terga: submedial tergal markings also less often appearing as pair of submedial streaks along entire dorsum of abdomen; lateral margins of abdominal terga 2-9 pale; tergum 10 brown, pale medially.  Posterolateral corners of segments 8 and 9 extended into sharp projections.

Take a look at the abdomens of the two nymphs my friend has found in her small stream in Sugar Hollow (which correspond to my nymph at the top of the page).

(Should be "on posterior edge of tergites.")

On the second nymph, we can very clearly see that the submedial tergal markings (the crescent-shaped marks) coalesce "forming [a] larger pale area in [the] posterior area of [the] terga."

Hmm... Very intriguing.  Still, remember that they insist that we must see the mouthparts to be certain of our ID.
____________________

Have to leave it there until sometime next spring.  In the meantime, the safe ID is "Paraleptophlebia debilis/jeanae."

A strong likelihood that this pronggilled is Paraleptophlebia debilis

I've been looking through photos I've taken of mayflies, looking for Pronggilled mayflies, and yesterday I came across this one, a picture I took in May of 2012.  If you look closely at the terga you'll note that this appears to be the same species of one of the nymphs my friend found in Sugar Hollow.

The same crescent shaped marks on the anterior edges of terga 4-6, and the markings on terga 7-10 match up as well.  Also of note, 1) the gills lack lateral branching, and 2) there are posterolateral projections on terga 8 and 9.

Those features alone -- the lack of tracheal branching and the posterolateral projections on 8 and 9 -- would lead to a Paraleptophlebia debilis ID in Mayflies by Knopp and Cormier (p. 269).   But I'd prefer to have additional confirmation.

Let's look at Donald Chandler's Key to Species of Leptophlebiidae.  Now, I no longer have a specimen that I can examine, which means I can't look at the maxillary palps, and that's a problem.  To be certain of our ID, we'd have to see palps on which -- in contrast to those we see on P. strigula and P. guttata (see the entries of 6/23 and 6/25) -- the "Segments of [the[ maxillary palpus [are] comparatively short."  But I think that that's a pretty good bet.  Why?  Because there are three species with "elongate" segments -- P. strigula, P. guttata, and P. ontario -- and we know from our previous entries that this is not strigula or guttata, and ontario has "Abdominal tergites [that] are largely yellowish with irregular brown markings."  No match there.

That takes us to dichotomy 9.

9. Abdominal tergites mottled; legs pale, barred with darker brown........paraleptophlebia debilis.
Legs uniformly brown or nearly so......10 

I'm fine with calling those terga "mottled," and the legs do look "pale [but] barred with darker brown," at least on the nymph that was found by my friend.
___________________

Not a certain ID.  But if my reasoning is solid, I think there's a pretty good chance that we've found a third Pronggilled species that inhabits our small cold-water streams.

Getting to know the Pronggilled mayflies

I went up to the upper stretch of the Doyles River this morning -- just short of where it flows out of the Shenandoah National Park.  I wasn't sure what I was going to find, but this one surprised me.  It's a Pronggilled mayfly that I've found at the Rapidan River and in the small streams in Sugar Hollow.  The upper Doyles -- in terms of size -- is somewhere in-between.  Paraleptophlebia guttata.

And I saw a lot of them.  At 6 mm, this was the largest, that most were smaller indicates they'll be around for awhile.

I decided to work more on the ID using two sources.  First, Unzicker and Carlson's article on "Ephemeroptera" in Aquatic Insects and Oligochaetes of North and South Carolina (pp. 3.59-3.60).  In their key, item 2. is

Tracheae of gills with conspicuous lateral branches.......................3
Tracheae of gills without conspicuous lateral branches..................4

Pretty clear from the first photo above that we move on to 4.  There we find

2nd and 3rd segments of each maxillary palp together 1.3 to 1.5 times the length of the 1st (basal) segment......................Paraleptophlebia guttata (McDunnough)

I measured -- no need to go further.  The segments of the maxillary palps, like those of P. strigula, are all "elongate" (to use Don Chandler's term), and I found that with this nymph, segments 2. and 3. combined were 1.38 times as long as 1.  Done.

But I also looked at Chandler's Key for the "Species of Leptophlebiidae," where after his description of the maxillary palps we find this.

8. Abdominal tergites largely dark, shining brown, with narrow pale submedian streaks at anterior margin; legs pale; length 7 mm; common in NH....................paraleptophlebia guttata

While my nymph only measured 6 mm, everything else is a match.  Here's a good shot of those "narrow pale submedian streaks" on the tergites.

Very pleased with the quality of the photos that I got this morning.

__________________

But I'm learning some things.  For example, 1) on my way out to the Doyles this morning I was pondering the difference between the pronggilled nymphs that have branched gills vs. those devoid of any branching.  Could it be that the "branching" helps with the absorption of dissolved oxygen? That might mean that those with branched gills are slightly more tolerant than those without.  After all, the species we find in the small, very clean streams in Sugar Hollow have gills that lack tracheal branching.  Have to give up on that theory. Previously, the only pronggilled nymphs that I've seen in the Doyles River are those with tracheal branching.  E.g., Paraleptophlebia sp. (mollis?)

and genus Leptophlebia.

But now we've got P. guttata in here as well.

2) Different pronggilled species seem to show up at different times.  The Paraleptophlebia. sp. (mollis?) nymph in the picture above was found in the month of March, the Leptophlebia nymph in the month of December.  No longer see either one.  At the moment P. guttata's the only show in town.  It appears to be a late spring/summer species.

And 3) while I thought P. guttata might be uncommon, I've been disabused of that idea.  It seems to be plentiful in the Doyles -- i.e. "common" -- as it is in NH, at least this time of year.
__________________

So much to learn. so little time.

Yes. It keys out to Paraleptophlebia strigula

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

Leptophlebia

Time to start paying attention.

Paraleptophlebia strigula? An intriguing possibility

A follow-up to my two previous entries.  As I was putting my copy of Knopp and Cormier away this morning, I took another quick look at their descriptions (Mayflies, p. 269) and noticed that they list another species of Paraleptophlebia that is found in the East -- P. strigula.  They describe the nymph as follows:  1) tracheal branching on gills: absent; 2) posterolateral projections or spines: present on abdominal segment 9; and 3) abdominal markings: "dark streaks along body margin".   Those "dark streaks" rang a bell.  Have a look.

Absolutely.  But is there a posterolateral projection on segment 9?

Yes!  And nothing on 8.  Hmm....

One problem.  This is a species that is not attested in the state of Virginia.  Its provenance is from New England down to Ohio and Pennsylvania.  But then, we're awfully close to Pennsylvania, so I'd not be surprised to find it in some of our streams.

I'm trying to learn more from entomologists.  Let you know what I find.

_________________

(See the tail end of yesterday's entry for a correction to my description of P. guttata.)