Saturday, July 19, 2014

So many colorful insects: waiting for the annual trip to Montana


I've had trouble this summer getting myself to go to the streams.  I don't like the hot humid weather, wading in water that's choked with vegetation, soaked with sweat while I wait for the condensation to dry on my lens.  All of this when I rather doubt that I'm going to see something new, that I'll be taking of photos of insects of which I all ready have some pretty good pictures.

So I find myself looking forward to that annual fishing trip to Montana.  Time to check my leaders and tippet spools, make sure my fly boxes are full -- need lots of "North Fork Specials"!    And I'll soon by oiling my reels and cleaning my lines.  It's all part of the fun.  But so too is the anticipation of seeing those beautiful larvae and nymphs that we don't find in the East and their beautiful patterns and colors.    For example...

I. Mayflies

1. That beautiful spiny crawler in the photo at the top of the page -- Drunella doddsi.  That's about as colorful as they get -- it's a very small nymph.


2. And the most common insect I see in the small, cold water streams, another spiny crawler, Drunella coloradensis, which comes in all sorts of colors.






3. And there's the weird spiny crawler, Timpanoga hecuba.


4. A flatheaded mayfly that we don't see in the East, Epeorus deceptivus.


5. And another, Nixe simplicioides.


6. Another strange looking mayfly, the pronggilled mayfly with "tusks" -- Paraleptophlebia bicornuta.


7.  And one that we do have here in the East, the little stout crawler, genus Tricorythodes (not sure, however, that this is a species we find.)



II. Caddisflies

1. A free-living caddisfly larva that I've seen only once (last summer), Rhyacophila Brunnea-Vemna group.


2. And the fairly common, common netspinner in the streams that I visit,  Arctopsyche grandis.



III. Stoneflies

And in Montana, there are still some nice stoneflies around at this time of the year.  E.g.

1. The very colorful, Claassenia sabulosa.


2. And, of course, there are still some "Salmon Flies" hanging around, Pteronarcys californica.

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So much to look forward to.  Does it have to be five weeks away?!  Below, the Blackfoot and the Bitterroot Rivers.



Saturday, July 12, 2014

Heterocloeon curiosum (small minnow mayfly) at the Rivanna: summer for sure


When I found this tiny nymph at Darden Towe this morning, I rushed out to take a few photos thinking I might have found the uncommon Heterocloeon petersi -- this one, which I found two years ago in the Rivanna at Crofton.


But I'm pretty sure I was wrong.  The little guy -- and it is a "guy" (male) -- in the first photo is probably a small, immature, Heterocloeon curiosum, an insect which is common at this site every summer.  When they mature, they look more like this.


Alas!  The Rivanna at Darden Towe is still a little bit high, but it's now perfectly safe to wade and scrounge up some bugs, and there were plenty of them to be found.  Lots of small flatheaded mayflies, a fair number of common netspinners -- even a whirligig beetle!  But let's stick with the H. curiosums since they too were around in good numbers.  Here is one of the females I found.


The females, you may recall, are always bigger than the males -- but less colorful.  But on the larger female, one of the key features of H. curiosum shows up very well: there is a dark splotch of pigment in the center of each of the gills.  Still, to be sure you have the small minnow mayfly H. curiosum, you have to see the little white gills that stick out at the base of the forecoxae.  These.


These nymphs are not easy to photograph: they don't stay in one place very long.  But, I'll get plenty of shots at good photos from now through September.
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Other photos.


1. The common netspinner, Hydropsyche rossi/venularis.   I think H. rossi and H. venularis are the only netspinners I see in the Rivanna, and they're fairly tolerant larvae (4.8 and 5.1 respectively).  I took photos of two of these insects this morning: one was brown, the other one green.



In the end I wasn't sure if they were H. rossi or H. venularis -- or possibly one of each.  The head pattern is much the same on both species: "Frontoclypeus with two pairs of yellow spots anterolaterally" (Schuster and Etnier, "a Manual for the Identification of the Larvae of the Caddisfly Genera Hydropsyche pictet and Symphitopsyche ulmer.., p. 96).  We can see those spots in this head shot of the brown nymph.


But to tell the two species apart, we must look at the rows of muscle scars on the sides of the head.  Do they, or do they not, "curve dorsad posteriorly" (Beaty, "The Trichoptera of North Carolina," p. 76).  Here are two microscope photos.  You decide.  I'm inclined to say they were H. rossi, but the evidence just isn't certain.



Best to exercise caution: H. rossi/venularis.
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2. A whirligig beetle larva, the first of the year: also a difficult photo to get.  They wiggle and wiggle and wiggle!



Nasty looking pincers.  This one was determined to get ahold of the H. curiosums.
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3. And last but not least, a Maccaffertium ithaca flatheaded mayfly: I found two.


It's great to get back into the Rivanna.  Every summer I find new things in this river.

Tuesday, July 8, 2014

What are Lepidostomatid case-makers doing in the Rivanna River in summer?


The water in the Rivanna is dropping and clearing -- and really warming up.  So I went to the Rivanna at Crofton to see if I could lift any rocks.  I could -- but I had to stick close to shore.  Still, I saw a lot of insects, though most things are small.


And I found, as you can see, a Lepidostomatid case-maker.  I've seen them before in this river, but it's something I don't understand.  The genus is the same that we see in the winter in spring -- Lepidostoma -- a larva which makes a four-sided case "constructed of quadrate pieces of plant material" (Beaty, "The Trichoptera of North Carolina," p. 81).  Tolerance value: 1.0.  We see a lot of these in the winter and spring, but they're always in small, very clean, cold mountain streams, often head water streams.  So what are they doing in this big, warm, not so clean river in summer?  I assume this is a matter of species, which, unfortunately have not yet been described.  Beaty names 22 species in North Carolina.   Whatever the answer, they're here, though not in very large numbers.


I have to admit that the cases made by those that I find in the winter are aesthetically much more pleasing.  And remember that some begin their cases with grains of sand.

Here's a pair that I found in Sugar Hollow on 3/3/12.


And another from 1/30/12.


I'll have to see what the entomologists say about this one.
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Other photos:

1. The "Rivanna River" Acroneuria abnormis Perlid.  No "M" visible on the head, and no banding on the terga.  (Have a look at the entry of 10/4/13.)  Still very small.



2. A VERY freckled genus Perlesta Perlid.  Note the setal row on the occiput and the presence of anal gills (= Perlesta).  (Red eyes = male?)



3. And among the many flatheaded mayflies I saw, I found our first Heptagenia of the season: Heptagenis marginalis.


Heptagenia flatheads, as opposed to Leurcrocuta flatheads, have "fibrilliform" on gill 7.


We'll get better photos of this one later on in the summer.  This one was taken on 8/8/12.



Tuesday, July 1, 2014

Rare, uncommon, unidentified: what we've found so far in our streams


It's always a pleasure for me to find EPT insects that Beaty notes as "rare" or "uncommon," or those that remain unidentified at this point in time.  While they're always noted in separate entries, in this entry I thought I'd pull all of that data together.  Beaty's comment is noted, and I've also cited the location at which the insect was found.

I. Mayflies (Ephemeroptera)

1. Small minnow mayfly, Heterocloeon petersi.  Found in the Rivanna River at Crofton.  Beaty -- "Listed as 'vulnerable to extirpation' by Morse et al. (1997)."  I've only found one.


2. Small minnow mayfly, Iswaeon anoka.  The Rivanna River at Darden Towe Park (Charlottesville).  Beaty -- "uncommon."  I've only found one.


3. Flatheaded mayfly, Rhithrogena sp., possibly R. exilis.  Buck Mt. Creek.   Beaty -- if it's exilis -- "Listed as 'vulnerable to extirpation' by Morse et al. (1997)."  I've only found one.


4. Spiny crawler mayfly, Drunella walkeri.  Doyles River and Buck Mt. Creek.  Beaty -- "uncommon in the mountains."  Seen a number of times.


5. Spiny crawler mayfly, Serratella serrata.  Doyles River.  Beaty -- "relatively uncommon and collected during summer only."  I've only found one.


6. Pronggilled mafyly, Habrophlebia vibrans.  Rapidan River.  Beaty -- "uncommon."  I've only found one.


7. Common burrower mayfly, Ephemera guttalata.  Small streams in Sugar Hollow.  Beaty -- "uncommon."  My friend and I have found this three times.


II. Stoneflies (Plecoptera)

1. Nemourid stonefly, genus Soyedina.  Small stream in Sugar Hollow.  Beaty -- "relatively rare."
We've seen these twice.


2. Large winter stonefly, Taenionema atlanticum.  Small streams in Sugar Hollow, Entry Run, Rapidan River.  Beaty -- "rarely collected."  ???  We see a lot of them in the winter.


3. Common stonefly, Agnetina capitata.  Entry Run, Greene County.  Beaty -- "Listed by NC Natural Heritage Program as Significantly Rare (2010)."  I've only seen one.


4.  Perlodid stonefly Helopicus subvarians.  Doyles River and Buck Mt. Creek.  Beaty -- "relatively uncommon."  I see a lot of them in the winter.


5.  Perlodid stonefly, Isogenoides hansoni.  Rapidan River.  Beaty -- "relatively rare."  I think I've seen this four times.


6. Perlodid stonefly, Isoperla similis. Rapidan River, small streams in Sugar Hollow.  Beaty -- "relatively uncommon."  I've seen them a number of times -- but not a lot.


7. Perlodid stonefly, Isoperla orata.  Rapidan River.  Beaty -- "uncommon."  I've seen a handful at the Rapidan; mostly late spring.


8.  Perlodid stonefly, Isoperla sp.  Rapidan River, Doyles River, Buck Mt. Creek.  Beaty -- "undescribed and unassociated larva" (personal communication).  I've seen quite a few of them at the Rapidan River.


9. Perlodid stonefly, Isoperla sp.  Small streams in Sugar Hollow.  Beaty -- "undescribed and unassociated larva" (personal communication).  Very common in Sugar Hollow in winter and spring.


10. Perlodid stonefly, Isoperla sp.  Small streams in Sugar Hollow.  Beaty -- "undescribed, unassociated larva" (personal communication).  Only seen twice.

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III. Caddisflies (Trichoptera)

1. Freeliving caddisfly larva, Rhyacophila glaberrima.  Small stream in Sugar Hollow, Entry Run in Greene County.  Beaty -- "relatively rare."  Found twice.


2. Fingernet caddisfly larva, genus Wormaldia.  Small streams in Sugar Hollow.  Beaty -- "uncommon."  I've seen it twice.


3. Humpless case-maker, Adicrophleps hitchcocki.  Small stream in Sugar Hollow.  NatureServe lists as "imperiled" in the state of Virginia."  Found only once by my friend who lives in Sugar Hollow.  The following photo was taken by her.


4. Northern case-maker, Pycnopsyche gentilis.  Small streams in Sugar Hollow.  Beaty -- "relatively uncommon." ??? We find them quite often in the winter and spring, some in three-sided cases of leaves, some in cases of pebbles, and some in "mixed media" cases.


5. Northern case-maker, Pseudostenophalyx sparsus.  Spring seep in Sugar Hollow.  Beaty -- "rare."  Found only once by my friend who lives in Sugar Hollow.  The following photo was taken by her.


6. Weighted case-maker, Goera fuscula.  Entry Run in Greene County.  Beaty -- "rare."  I've seen them twice.


7. Uenoid caddisfly larva, Neophylax fuscus.  South River, Buck Mt. Creek, Moormans River.  Beaty -- "relatively rare."  Found three times.


8. Strong case-maker, Psilotreta frontalis.  Small, temporary stream in Doyles River Valley.  Beaty -- "less than 60 BAU records."  Only seen once.

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When the weather improves, I'll be out looking for more nymphs and larvae to add to this list.