Aquatic Insects of Central Virginia: More streams at Byrom Park --- and more Rhyacophilids

It was pretty much a caddisfly day at Byrom Park (see the posting of February the 10th), at least in terms of the photos I chose to take. To be honest I was mainly interested in exploring new water. I didn't venture up to the streams at high elevation -- I'll save that for spring. Rather, I decided to look in a very small stream that was not too far from the parking lot. This one.

Beautiful water. But I did have to climb over some boulders and crawl through the thorns -- that wasn't pleasant!

The Rhyacophilids (free-living caddisfly larvae) in the photo at the top of the page are not R. nigrita, which is the species I found here last month. I wasn't really sure what they were: I was not all that sure they were both the same species. But they were both part of the Banksi complex of the Invaria Group, possibly R. banksi itself (the posting of 1/28 focussed on this complex, and you might want to look back to that entry before you proceed.)

I didn't know what to make of the head colors -- one very dark, the other golden brown.

But it turns out that that variation is common. Weaver and Sykora (1979) on R. banksi: "Overall length 16 mm, Head: Coloration variable; in some, golden brown, in others dark brown with an irregular row of pale muscle scars extended on each side of the front and the coronal suture." With the microscope, the muscle scars on the dark headed larva were easy to see (and see the photos posted on 1/28); no scars at all on the one with that was more lightly colored.

For the full description of this species, I'd refer you back to 1/28. No question at all that that's what we found.

More species further upstream? Only one way to know.
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Caddisfly number two. The common netspinner we find in our small mountain streams, Diplectrona modesta (TV, 2.3).

I should be seeing them in Sugar Hollow as well, but nothing so far.
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And then there were the Uenoids! Little cases all over the rocks. I picked up a few, hoping to find a new species, Neophylax ornatus, but I think I'll have to start climbing the hills to find that one. Today it was N. mitchelli and N. aniqua, two that I often find in the same place. N. mitchelli, has the pointed tubercle that points towards the back of the head.

One larva actually came out of its case which allowed for some unusual photos.

N. mitchelli has ventral clavate gills on segment 1, but they were just too small to show up in these photos.
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Mayflies? I again found Ameletids, and I saw a lot of tiny Epeorus pleuralis. Oh, and I also saw quite a few "tiny spinys": Ephemerellas, probably E. invaria. For stoneflies -- I saw a number of Clioperla clio Perlodids which I refused to put into my tray (they eat everything in sight!). I did photograph a mature Taenionema atlanticum large winter and a fairly mature P. proteus Giant.