Wednesday, April 3, 2013

A Tale of Two Streams: South River and Entry Run

As you know, I've posted a lot entries on my findings up at South River (Greene County).  The truth is that a lot of insects I've found in the "South" have actually come from "Entry Run" a small tributary that runs into the South right below the section that I explore.   You can see the relationship in this photo: I explore the South right above the bridge in the upper left of the photo.

The most intolerant insects I find at this site are in Entry Run: the variety of insects in Entry Run is astounding -- as you will see.

I. South River

The bottoms of rocks in South Run are absolutely covered with E. pleuralis nymphs, the flathead in the photo at the top of the page, and like the one in the photo, many are fully mature -- nice long, black wing pads.   If I were fishing this stream -- and it does hold populations of trout -- I'd carry lots of Quill Gordon imitations.

But there's another fly that you'll want to carry -- the Blue Quill.  For the other insect that's maturing right at the moment is the pronggilled mayfly, genus Paraleptophlebia.

With the size of those eyes, I'd guess that this nymph is a male -- but I don't really know that for sure.

The other insect that was fairly common this morning in the South River was our small mountain stream, small minnow mayfly -- Baetis tricaudatus.

These, too, are maturing, though the wing pads haven't turned black.  By this time last year, I was already finding mature B. tricaudatus nymphs, but I think things are dragging this year because of the cold weather we've had throughout the winter.

I also saw a fair number of Isoperla namatas (Perlodid stoneflies) and one or two spiny crawlers -- but that's about it for the South.

II. Entry Run

Let me post a list of all of the insects I found in this stream this morning; then we'll turn to the photos.

Stoneflies: Giant stoneflies (Pteronarcys proteus); Common stoneflies (Acroneuria abnormis); Roach-like stoneflies (genus Tallaperla); Perlodid stoneflies (Isoperla namata and Diploperla duplicata); a Leuctrid (Rolled-winged stonefly); and a Chloroperlid (genus Sweltsa).

Mayflies: Small minnow mayflies (Baetis tricaudatus); Flatheaded mayflies (Epeorus pleuralis, Maccaffertium pudicum, and a Maccaffertium species unknown); Brush-legged mayflies (Isonychia); and Spiny crawler mayflies (Ephemerella invaria).

Caddisflies: Free-living caddisflies (Rhyacophila fuscula and Rhyacophila carolina); Common netspinners (Ceratopsyche alhedra and Cheumatopsyche); Fingernet caddisfly (genus Dolophilodes); a Lepidostomatid; and several Strong case-makers which were sealed in pupation.

Pretty impressive, and I really wasn't looking that long!  (Oh yes -- and water pennies, black flies and midges.)

Some photos of Entry Run insects.

1. Free-living caddisfly larva, R. fuscula.  This one was around 1" long.

R. fuscula larvae should start to pupate anytime now.  Here's one in its cocoon that I found in Entry Run on March 26th of last year.

2. Another very nice B. tricaudatus small minnow mayfly.

3. Spiny crawler mayfly, Ephemerella invaria.

4. A lonely Lepidostomatid case-maker caddis.  I thought they were all sealed away in pupation.

5. Perlodid stonefly, Diploperla duplicata.  Getting bigger -- but still a long way to go.  Note that the posterior edge of the wing pads has barely started to bow.

6. And an Isoperla namata, one of many.  The leaf packs -- both in the South and in Entry Run -- were full of them.

These too, it seems to me, ought to be further along in development.  By now, some should have blacker wing pads -- like this nymph that I found in the South on March 26th of last year.

A patch of Coltsfoot grows by the stream.  Where I lived in Vermont (for 27 years), Coltsfoot was the first wildflower I saw in the spring, followed by Bloodroot and Trout-lily.  Gee, maybe spring is finally here!

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